The effects of omega-3 fatty acids supplementation on hemoglobin, hematocrit, and platelet levels of patients with ESRD condition undergoing dialysis

Background

Concomitant inflammation may boost the cardiovascular complications in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD). Omega-3 fatty acids may have certain health benefits in HD patients. The aim of this study was to investigate the effects of omega-3 fatty acids supplementation on hematocrit (HCT), hemoglobin (HB) level and platelet (PLT) counts of HD patients.

Methods

A randomized controlled trial was conducted on HD patients at a private dialysis center in Rasht, Iran. Three omega-3 fatty acid supplement capsules (3 g/d) were administered daily for two months to patients in the intervention group (n = 55). The control group (n = 60) were given three placebo capsules containing medium chain triglyceride (MCT) oil, similar to the supplemental dose of the intervention group at the same period. Three parameters of HCT, HB and PLT were measured at baseline and after the intervention.

Results

The PLT count decreased in the intervention group compared to the control group (173.38 ± 74.76 vs. 227.68 ± 86.58 103/mm3, F = 4.83, P = 0.03). No significant change was found on the levels of HCT and HB parameters between the two groups after the intervention.

Conclusion

Omega-3 supplementation in HD patients may decrease the risk of forming blood clots in the blood vessels. Further studies are warranted.

Association of iron supplementation, HFE and AMPD1 polymorphisms and biochemical iron metabolism parameters in the performance of a men's World Tour cycling team: A pilot study

BACKGROUND

Nutritional strategies with iron supplementation have been shown to be effective in preventing the decline of blood biochemical parameters and sports performance. The aim of the study was to describe biochemical iron metabolism parameters in association with iron supplementation and HFE and AMPD1 polymorphisms in a Union Cycliste Internationale (UCI) World Tour cycling team to evaluate performance during a whole season METHODS: Twenty-eight professional men cyclists took part in this longitudinal observational pilot study. AMPD1 c.34 C>T (rs17602729) and HFE c.187 C>G (rs1799945) polymorphisms were genotyped using Single Nucleotide Primer Extension (SNPE). All the professional cyclists took oral iron supplementation throughout the season. Four complete blood analyses were carried out corresponding to UCI controls in January (1st), April (2nd), June (3rd) and October (4th). Data on participation in three-week Grand Tours, kms of competition and wins were analyzed.

RESULTS

In performance, especially in wins, there was a significant effect in HFE on biochemical hemoglobin (F = 4.255; p = 0.021) and biochemical hematocrit (F = 5.335; p = 0.009) and a hematocrit biochemical × genotype interaction (F = 3.418; p = 0.041), with higher values in professional cyclist with GC genotype. In AMPD1 there were significant effects in the biochemical iron x genotype interaction in three-week Grand Tours (F = 3.874; p = 0.029) and wins (F = 3.930; p = 0.028) CONCLUSIONS: Blood biochemical iron metabolism parameters could be related to performance in the season due to increasing hemoglobin and hematocrit concentration under iron supplementation, associated with winning in the professional cyclists with GC genotype of the HFE polymorphism.

Hematocrit drift and outcomes in surgical patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

There is a paucity of conclusive evidence regarding the impact of downward drift in hematocrit levels among patients who have undergone surgical clipping for aneurysmal subarachnoid hemorrhage (aSAH). This study endeavors to explore the potential association between hematocrit drift and mortality in this specific patient population.

METHODS

A cohort study was conducted, encompassing adult patients diagnosed with aSAH at a university hospital. The primary endpoint was follow-up mortality. Propensity score matching was employed to align patients based on their baseline characteristics. Discrimination capacity across various models was assessed and compared using net reclassification improvement (NRI).

RESULTS

Among the 671 patients with aSAH in the study period, 118 patients (17.6%) experienced an in-hospital hematocrit drift of more than 25%. Following adjustment with multivariate regression analysis, patients with elevated hematocrit drift demonstrated significantly increased odds of mortality (aOR: 2.12, 95% CI: 1.14 to 3.97; P = 0.019). Matching analysis yielded similar results (aOR: 2.07, 95% CI: 1.05 to 4.10; P = 0.036). The inclusion of hematocrit drift significantly improved the NRI (P < 0.0001) for mortality prediction. When in-hospital hematocrit drift was served as a continuous variable, each 10% increase in hematocrit drift corresponded to an adjusted odds ratio of 1.31 (95% CI 1.08-1.61; P = 0.008) for mortality.

CONCLUSIONS

In conclusion, the findings from this comprehensive cohort study indicate that a downward hematocrit drift exceeding 25% independently predicts mortality in surgical patients with aSAH. These findings underscore the significance of monitoring hematocrit and managing anemia in this patient population.

Impacts of temperature and turbidity on the gill physiology of darter species

Fish gills are complex organs that have direct contact with the environment and perform numerous functions including gas exchange and ion regulation. Determining if gill morphometry can change under different environmental conditions to maintain and/or improve gas exchange and ion regulation is important for understanding if gill plasticity can improve survival with increasing environmental change. We assessed gill morphology (gas exchange and ion regulation metrics), hematocrit and gill Na+/K+ ATPase activity of wild-captured blackside darter (Percina maculata), greenside darter (Etheostoma blennioides), and johnny darter (Etheostoma nigrum) at two temperatures (10 and 25 °C) and turbidity levels (8 and 94 NTU). Samples were collected August and October 2020 in the Grand River to assess temperature differences, and August 2020 in the Thames River to assess turbidity differences. Significant effects of temperature and/or turbidity only impacted ionocyte number, lamellae width, and hematocrit. An increase in temperature decreased ionocyte number while an increase in turbidity increased lamellae width. Hematocrit had a species-specific response for both temperature and turbidity. Findings suggest that the three darter species have limited plasticity in gill morphology, with no observed compensatory changes in hematocrit or Na+/K+ ATPase activity to maintain homeostasis under the different environmental conditions.

Hematocrit control and thrombotic risk in patients with polycythemia vera treated with ruxolitinib in clinical practice

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by unregulated red blood cell production resulting in elevated hemoglobin and/or hematocrit levels. Patients often have symptoms such as fatigue, pruritus, and painful splenomegaly, but are also at risk of thrombosis, both venous and arterial. Ruxolitinib, a selective Janus kinase inhibitor, is approved by the US Food and Drug Administration as second-line cytoreductive treatment after intolerance or inadequate response to hydroxyurea. Although ruxolitinib has been widely used in this setting, limited data exist in the literature on ruxolitinib treatment patterns and outcomes among patients with PV in routine clinical practice. We report a retrospective, observational, cohort study of patients treated for PV with ruxolitinib across three US centers (academic and regional practice) from December 2014-December 2019. The study included 69 patients, with a median follow-up duration of 3.7 years (95% CI, 2.9-4.4). Our data demonstrate very high rates of hematocrit control (88% of patients by three months and 89% by six months); few patients required dose adjustments or suspension. No arterial thromboses were observed; however, the follow-up duration does not allow for the generation of meaningful conclusions from this. Three patients had thrombotic events; one was in the setting of a second malignancy, one post-operative, and a third related to prolonged immobility. We also found that 28% of patients initiated ruxolitinib as a result of poorly controlled platelet counts, second only to hydroxyurea intolerance (46%) as a reason to start therapy. In clinical practice, ruxolitinib continues to be effective in controlling hematocrit levels after three and six months of treatment in patients and is associated with low thrombotic risk.

Testosterone Replacement Therapy: Effects on Blood Pressure in Hypogonadal Men

PURPOSE

While testosterone therapy can improve the various pathologies associated with adult-onset testosterone deficiency (TD), Summary of Product Characteristics (SPC) of five testosterone preparations caution that treatment may be associated with hypertension. This paper evaluates the impact of testosterone undecanoate (TU) on blood pressure (BP) in men with adult-onset TD.

MATERIALS AND METHODS

Of 737 men with adult-onset TD in an on-going, observational, prospective, cumulative registry, we studied changes in BP using non-parametric sign-rank tests at final assessment and fixed time points. We used multiple regression analysis to establish factors (baseline BP, age, change/baseline waist circumference [WC] and hematocrit [HCT] and follow-up) potentially associated with BP change in men on TU.

RESULTS

TU was associated with significant reductions in systolic, diastolic BP and pulse pressure, regardless of antihypertensive therapy (at baseline or during follow-up), larger reductions were seen with concurrent antihypertensive therapy. In men never on antihypertensive agents, median changes (interquartile range [IQR]) in systolic BP, diastolic BP and pulse pressure were -12.5 (-19.0, -8.0), -8.0 (-14.0, -3.0), and -6.0 (-10.0, -1.0) mmHg, respectively at final assessment, with only baseline BP values inversely associated with these changes (HCT and WC were not significantly associated). In men not on TU, systolic BP, diastolic BP, and pulse pressure significantly increased. In the TU treated men only 1 of the 152 men (not on antihypertensive agents at baseline) were started on antihypertensives during follow-up. In contrast 33 of the 202 men on antihypertensives (at baseline or follow-up) had the antihypertensive agent discontinued by the end of the follow-up.

CONCLUSIONS

TU was associated with lowering of BP during follow-up irrespective of antihypertensive therapy, with greater reductions in men with higher baseline BP. In the context of SPC warnings, our long-term data provide reassurance on the effect of TU on BP.

The effect of polycythemia vera on choroidal thickness and retrobulbar blood flow

BACKGROUND

To evaluate the choroidal thickness and retrobulbar hemodynamic parameters in polycythemia vera (PV) patients in comparison with healthy individuals, and to investigate the relationship of these values with blood hematocrit levels.

METHODS

This prospective study included the 35 eyes of 35 PV patients and the 30 eyes of 30 healthy individuals. Choroidal thickness was measured at the subfoveal area and at 500 µm intervals nasal and temporal to the fovea up to a distance of 1500 µm. Color Doppler ultrasonography (CDU) was used to evaluate the retrobulbar vessels. Complete blood count values were recorded.

RESULTS

Choroidal thickness was found to be significantly lower in the PV group than in the control group at the subfoveal, nasal 500, and temporal 500 and 1000 µm measurement points (p = 0.01, p = 0.011, p = 0.04, p = 0.045, respectively). The central retinal artery (CRA) peak systolic velocity (PSV) and end diastolic velocity (EDV) values and the ophthalmic artery (OA) PSV value were significantly lower in the PV group than in the control group (p < 0.001, p < 0.001, p = 0.019, respectively). No significant difference was present between the groups in terms of CRA and OA resistive index (RI) and pulsatile index (PI) values (p = 0.388, p = 0.564, p = 0.897, p = 0.693, respectively). A negative correlation was found between the blood hematocrit levels and the subfoveal, nasal 500 µm, and temporal 500 µm choroidal thickness measurements and the CRA PSV and EDV and the OA PSV values.

CONCLUSIONS

PV may cause microvascular changes and lead to ocular vascular complications by affecting the choroidal and retrobulbar blood flow.

The importance of personalization in high altitude protocols for hematologic and metabolic benefits in sports: A multi-dimensional N-of-1 case study

The hematologic and metabolic benefits of high altitude exposure have been extensively studied in athletes due to their promising performance enhancing effects. However, despite the increased research and development of various high altitude protocols for achieving peak performance, the reproducibility of the results at the individual level remains sparse. To systematically address this limitation and establish a more effective method to achieve consistent results at the individual level, we conducted a multi-dimensional study of one elite endurance athlete in two Phases. In Phase 1, we applied the standard protocol of LHTH (Live-High-Train-High) using a commercially available, at-home, normobaric, high altitude simulation tent under the SHTL (Sleep-High-Train-Low) model. Then, we developed the athlete's personalized protocol for peak hematologic parameters during their off-season. This protocol determined the exact total high altitude exposure time required to achieve peak hematologic parameters, which in the case of this athlete, amounted to 45 nights with approximately 8hrs per night. In Phase 2, we replicated the Phase 1 protocol during the athlete's in-season and observed the same or even higher hematologic and metabolic benefits compared to Phase 1. During both phases, we collected thousands of multi-dimensional data points to ensure that the athlete's lifestyle and environmental factors remained stable, and to increase the likelihood that physiological changes resulted primarily from the high altitude exposure. The data trends in both Phases validated that, for this athlete, hematologic measures such as red blood cell count, hematocrit, and hemoglobin, as well as electrolyte content, body weight and gut microbiome composition improved to their personal best values after a total of approximately 15 days of high altitude exposure (45 nights with roughly 8hrs per night totaling 360hrs or 15days). These improvements did not occur after the 21 days recommended by the LHTH protocol highlighting the significance of personalization in high altitude protocols that are designed for peak performance parameters. Therefore, to maximize the benefits in hematologic and other metabolic values and thus increase muscle oxygen supply and peak aerobic capacity through high altitude exposure, each athlete may require a unique total duration of high altitude exposure tailored to their individual physiology. This duration must be determined by their specific response in hematologic peaking. Therefore, initially establishing a personalized protocol for an athlete by determining their required total duration of high altitude exposure for peak hematologic values during their off-season and applying this protocol during their in-season phase may lead to more successful and reproducible benefits compared to following a generalized protocol alone.

A comparative study of synthetic and venous hematocrit for calculating cardiovascular magnetic resonance-derived extracellular volume

The extracellular volume (ECV) fraction derived from cardiac magnetic resonance (CMR) can reflect various pathologies. The application of ECVs was limited by the strict requirement that hematocrit (Hct0) should be obtained within 24 hours of CMR scan. The aim of this study was to obtain accurate and convenient ECV calculated from the venous Hct and synthetic Hct in CMR. A total of 839 subjects were retrospectively enrolled. The subjects were divided into derivation cohort for local sex-specific models and validation cohort for assessing the accuracy of different ECVs. In the validation cohort, venous Hcts from 7 days before the scan (Hct1 - 7), outside 7 days (Hct> 7), the closest day (Hctclosest), and Hctsyn were compared with Hct0. The agreement and correlation of the conventional ECV (ECV0) with the corresponding ECVs were analyzed. The factors affecting the accuracy of ECVsyn were assessed. ECV1-7 and ECVclosest had the best correlation and smallest bias with ECV0 (R = 0.959 and 0.951, bias = 0.02% and - 0.03%). When using an absolute 2% error as the standard, the performance of ECV1-7 was the best, with an accuracy of 81.0%, followed by ECVclosest (78.8%), ECV> 7 (77.2%) and ECVsyn (70.7%). Abnormally low and high Hcts and decreased left ventricular ejection fractions were associated with miscalculation of ECVsyn, especially patients with dilated cardiomyopathy. We recommend extending the time interval between a Hct and a CMR scan to 7 days for ECV calculation. The synthetic ECV should be used cautiously, especially for patients with extremely low or high Hcts, decreased cardiac function, and dilated cardiomyopathy.

Calcium flux alterations in erythrocytes from sickle cell mice: The relevance of mean corpuscular volume

Red blood cells (RBC) from patients with sickle cell disease (SCD) have elevated calcium levels at baseline, which are further elevated upon deoxygenation. Here we examined baseline calcium levels and calcium flux in RBCs from a mouse model of SCD mice. We found that akin to humans with SCD, sickle (HbSS) Townes mice, have higher baseline levels and increased calcium flux in RBCs compared to control (HbAA) animals. As HbSS mice, unlike humans with SCD, have high mean corpuscular volume compared with HbAA, we highlight the importance of adjusting biochemical results to number of RBCs rather than hematocrit during the analysis and interpretation of the results. Our findings add to the face validity of humanized sickle cell mice and support its use for studies of RBC calcium flux in SCD.

Evaluation of Blood Loss in Third-Generation Internal Ultrasound-Assisted Liposuction

BACKGROUND

In large-volume liposuction procedures, one of the most important limitations of total lipoaspirate volume is blood loss. In this study, we aimed to determine the amount of blood loss in individuals who underwent a third-generation internal ultrasound-assisted liposuction (UAL).

METHODS

Eleven female and eleven male participants with a mean age of 35.31 (range 20-47) were included in this prospective study. The third-generation internal UAL was performed on multiple anatomical regions using the VASER® Internal Ultrasound Device (Sound Surgical Technologies; Louisville, CO). The demographic characteristics of the participants, the amount of aspirate collected, and hemoglobin (Hgb) and hematocrit (Htc) values before and after the third-generation internal UAL were evaluated.

RESULTS

The mean third-generation internal UAL time was 74.81 ± 17.95 minutes, and the mean aspiration amount was 5,122.27 ± 1,597.43 ml. The aspirated amount was 6.64% ± 2.20 of body weight. The mean Hgb value was 13.87 ± 1.99 before the third-generation internal UAL and 11.26 ± 2.16 (g/dL) after the third-generation internal UAL (z = 4.108, p < 0.001). The mean reduction in Hgb levels with the third-generation internal UAL was 2.61 ± 1.73 and 0.53 ± 0.36 per liter of aspirate taken. The mean Htc value after the third-generation internal UAL was 33.91 ± 6.03 and was significantly lower than the mean Htc value before the third-generation internal UAL, 41.39 ± 5.13 (z = -3.946, p < 0.001). The mean reduction in Htc with the third-generation internal UAL was 7.48 ± 5.42, and the Htc value decreased by 1.50 ± 1.13 per liter of aspirate ingested. The amount of aspirated supernatant was responsible for 44.4% of the change in Hgb and 30.9% of the change in Htc after the third-generation internal UAL.

CONCLUSION

Knowing the reduction rates in Hgb and Htc with the third-generation internal UAL is useful to plan the amount of aspirate to be taken, the amount of blood loss that may occur with the third-generation internal UAL, and the postoperative care of the patients.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Masked anemia and hematocrit elevation under sodium glucose transporter inhibitors: findings from a large real-world study

AIMS

Sodium glucose transporter inhibitors (SGLT2i) therapy is associated with an increase in hematocrit as a class effect. There is a lack of information regarding the clinical magnitude and significance of hematocrit elevation, especially cardiovascular outcomes in patients with polycythemia and possible masking of lower hemoglobin levels as a sign of potential severe disease.

METHODS

A retrospective study utilizing large community healthcare provider electronic database. Hematocrit levels and variables with potential effect on hematocrit change were compared before and during SGLT2i treatment in adults with type 2 diabetes mellitus.

RESULTS

Study population included 9646 patients treated with Dapagliflozin or Empagliflozin between 01.2015 and 06.2019. Hematocrit levels were significantly higher after treatment initiation (2.1%), with higher median elevation among male vs female (2.3% vs. 1.8%). Anemia prevalence was significantly lower under treatment (20% vs. 31.6%). In multivariable model, gender, smoking status, SGLT2i type, pretreatment hematocrit, diabetes duration, body mass index and estimated glomerular filtration rate change significantly effected hematocrit change.

CONCLUSIONS

In the current study SGLT2i treatment was associated with significant hematocrit elevation, polycythemia and lower anemia prevalence. Further studies are needed to determine the clinical significance and approach to patients with pretreatment or on treatment polycythemia and the approach to patients with lower-normal hemoglobin levels under SGLT2i treatment.

Prediction of hematocrit decline and the impact of peri-operative fluid use in lumbar spinal fusion surgery

PURPOSE

Peri-operative blood loss unaccounted for and post-operative hematocrit decline could have a significant impact on the outcome of elective spinal surgery patients. The study assesses the accuracy of predictive models of hematocrit decline and blood loss in spinal surgery and determines the impact of peri-operative fluid administration on hematocrit levels of patients undergoing first-time single level lumbar fusion surgery for degenerative spine disease and the trend thereof in the first 24 h post-operatively.

METHODS

Clinical and biochemical parameters were prospectively collected in patients undergoing single level lumbar spinal surgery. Predictive models were applied to assess their accuracy in intra-operative blood loss and post-operative hematocrit decline.

RESULTS

High correlation (0.98 Pearson correlation coefficient) occurred between calculated (predicted) and recorded hematocrit from hours 2 to 6 post-operatively. Predictive accuracy declined thereafter yet remained moderate. Patients received an average intra-operative fluid volume of 545.45 ml per hour (47% of estimated total blood volume). A significant hematocrit decline occurred post-induction (43.47-39.78%, p < 0.001) with total fluid volume received being the significant contributing variable (p < 0.001). Hypertensive patients were the only subgroup to drop below the safe hematocrit threshold of 30%.

CONCLUSION

Iatrogenic hemodilution can accurately be predicted for the first six hours post-operatively, with high risk patients identifiable. Fluid therapy should be goal directed rather than generic, and good communication between the surgeon and anesthesiologist remains the cornerstone to manage physiological changes secondary to blood loss. Although helpful, predictive formulas are not universally applicable to all phenotypes.

A high-throughput LC-MS/MS assay for piperaquine from dried blood spots: Improving malaria treatment in resource-limited settings

Background

Malaria is a parasitic disease that affects many of the poorest economies, resulting in approximately 241 million clinical episodes and 627,000 deaths annually. Piperaquine, when administered with dihydroartemisinin, is an effective drug against the disease. Drug concentration measurements taken on day 7 after treatment initiation have been shown to be a good predictor of therapeutic success with piperaquine. A simple capillary blood collection technique, where blood is dried onto filter paper, is especially suitable for drug studies in remote areas or resource-limited settings or when taking samples from children, toddlers, and infants.

Methods

Three 3.2 mm discs were punched out from a dried blood spot (DBS) and then extracted in a 96-well plate using solid phase extraction on a fully automated liquid handling system. The analysis was performed using LC-MS/MS with a calibration range of 3 - 1000 ng/mL.

Results

The recovery rate was approximately 54-72 %, and the relative standard deviation was below 9 % for low, middle and high quality control levels. The LC-MS/MS quantification limit of 3 ng/mL is sensitive enough to detect piperaquine for up to 4-8 weeks after drug administration, which is crucial when evaluating recrudescence and drug resistance development. While different hematocrit levels can affect DBS drug measurements, the effect was minimal for piperaquine.

Conclusion

A sensitive LC-MS/MS method, in combination with fully automated extraction in a 96-well plate format, was developed and validated for the quantification of piperaquine in DBS. The assay was implemented in a bioanalytical laboratory for processing large-scale clinical trial samples.

Risk of deep vein thrombosis (DVT) in lower extremity after total knee arthroplasty (TKA) in patients over 60 years old

PURPOSE

There is a significant risk of DVT after TKA. We aim to evaluate the potential risk factors for postoperative DVT in the lower extremities in TKA patients over 60 years of age and provide a reference for the effective prevention of DVT.

METHODS

This retrospective study included patients older than 60 who underwent TKA surgery in our hospital from May 2015 to May 2022 and compared and analyzed patients' personal characteristics and clinical data with or without postoperative DVT. Logistic regression analysis was performed to determine the potential risk factors for DVT after TKA. The sensitivity and specificity of each risk factor in the diagnosis of DVT were compared by the ROC curve, and the value of this model in the diagnosis of DVT was further investigated using a multivariable combined diagnosis ROC curve model.

RESULTS

A total of 661 patients over 60 who underwent TKA were included. Preoperative Hematocrit (HCT), platelet count, anesthesia mode, postoperative D-dimer, ESR, diabetes mellitus, and other aspects of the DVT group and non-DVT group were statistically significant after TKA (P < 0.05). Multivariate logistics regression analysis showed that preoperative HCT, anesthesia mode, and diabetes were independent risk factors for DVT in patients over 60 years old after TKA. Compared with the univariate ROC model, the multivariable combined ROC curve analysis model has a higher diagnostic value for the diagnosis of DVT.

CONCLUSION

DVT is common in patients over 60 years of age after TKA, and there is a multivariable influence on its pathogenesis. For patients over 60 with diabetes, neuraxial anesthesia is recommended for patients with high preoperative HCT levels, which may reduce the incidence of postoperative DVT.

Performance Evaluation of Geometrically Different Pediatric Arterial Cannulae in a Pediatric Cardiopulmonary Bypass Model

OBJECTIVE

To define a reference chart comparing pressure drop vs. flow generated by a set of arterial cannulae currently utilized in cardiopulmonary bypass conditions in pediatric surgery.

METHODS

Cannulae from two manufacturers were selected considering their design and outer and inner diameters. Cannula performance was evaluated in terms of pressure drop vs. flow during simulated cardiopulmonary bypass conditions. The experimental circuits consisted of a Jostra HL-20 roller pump, a Quadrox-i pediatric oxygenator (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set. The circuit was primed with lactated Ringer's solution only (first condition) and with human packed red blood cells added (second condition) to achieve a hematocrit of 30%. Cannula sizes 8 to 16 Fr were inserted into the cardiopulmonary bypass circuit with a "Y" connector. The flow was adjusted in 100 ml/min increments within typical flow ranges for each cannula. Pre-cannula and post-cannula pressures were measured to calculate the pressure drop.

RESULTS

Utilizing a pressure drop limit of 100 mmHg, our results suggest a recommended flow limit of 500, 900, 1400, 2600, and 3100 mL/min for Braile arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, respectively. For Medtronic DLP arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, the recommended flow limit is 600, 1100, 1700, 2700, and 3300 mL/min, respectively.

CONCLUSION

This study reinforces discrepancies in pressure drop between cannulae of the same diameter supplied by different manufacturers and the importance of independent translational research to evaluate components' performance.

Core-Shell Microfiber Encapsulation Enables Glycerol-Free Cryopreservation of RBCs with High Hematocrit

Cryopreservation of red blood cells (RBCs) provides great potential benefits for providing transfusion timely in emergencies. High concentrations of glycerol (20% or 40%) are used for RBC cryopreservation in current clinical practice, which results in cytotoxicity and osmotic injuries that must be carefully controlled. However, existing studies on the low-glycerol cryopreservation of RBCs still suffer from the bottleneck of low hematocrit levels, which require relatively large storage space and an extra concentration process before transfusion, making it inconvenient (time-consuming, and also may cause injury and sample lose) for clinical applications. To this end, we develop a novel method for the glycerol-free cryopreservation of human RBCs with a high final hematocrit by using trehalose as the sole cryoprotectant to dehydrate RBCs and using core-shell alginate hydrogel microfibers to enhance heat transfer during cryopreservation. Different from previous studies, we achieve the cryopreservation of human RBCs at high hematocrit (> 40%) with high recovery (up to 95%). Additionally, the washed RBCs post-cryopreserved are proved to maintain their morphology, mechanics, and functional properties. This may provide a nontoxic, high-efficiency, and glycerol-free approach for RBC cryopreservation, along with potential clinical transfusion benefits.

Study of the link between hemotopoietic and skeletal systems in patients attending a referral center for osteoporosis

PURPOSE

To investigate the link between hematopoietic and skeletal tissues in patients with fragility fractures.

METHODS

We retrospectively analyzed the medical records of women older than 40 years who attended the Bone Disease Unit of "Sapienza" University of Rome for their first visit for osteoporosis from January 2020 to June 2022.

RESULTS

Fragility fractures were found in 61.8% of the sample. In particular, vertebral fractures in 35.5%, femoral fractures in 6.3%, Colles fractures in 16.5% and non-vertebral non-hip in 42.5%. Fractured patients were significantly older compared to non-fractured, had lower mean values of lumbar spine (p = 0.01), and femoral neck BMD (p = 0.007). A red blood cell distribution width (RDW) value higher than 15% was observed four times more in those with fractures compared to non-fractured patients (8.9% vs 2%, p = 0.01) and was associated with vertebral fracture after adjusting for age, BMI, menopause, nutritional status, smoking, osteoporosis and anemia (OR = 4.1, 95% CI 1.6-11.4, p = 0.003). Hematocrit was negatively associated with hip fracture also adjusting for age, BMI, menopause, nutritional status, smoking, osteoporosis (p = 0.025).

CONCLUSION

Our study demonstrates that RDW values were significantly associated with vertebral fracture and hematocrit with hip fracture. Since both parameters are included in the initial evaluation of patients with suspected bone fragility, our results should push doctors to look at these values with no incremental cost for national health services.

Hydration and evaporative water loss of lizards change in response to temperature and humidity acclimation

Testing acclimation plasticity informs our understanding of organismal physiology and applies to conservation management amidst our rapidly changing climate. Although there is a wealth of research on the plasticity of thermal and hydric physiology in response to temperature acclimation, there is a comparative gap for research on acclimation to different hydric regimes, as well as the interaction between water and temperature. We sought to fill this gap by acclimating western fence lizards (Sceloporus occidentalis) to experimental climate conditions (crossed design of hot or cool, dry or humid) for 8 days, and measuring cutaneous evaporative water loss (CEWL), plasma osmolality, hematocrit and body mass before and after acclimation. CEWL changed plastically in response to the different climates, with lizards acclimated to hot humid conditions experiencing the greatest increase in CEWL. Change in CEWL among individuals was negatively related to treatment vapor pressure deficit and positively related to treatment water vapor pressure. Plasma osmolality, hematocrit and body mass all showed greater changes in response to temperature than to humidity or vapor pressure deficit. CEWL and plasma osmolality were positively related across treatment groups before acclimation and within treatment groups after acclimation, but the two variables showed different responses to acclimation, suggesting that they are interrelated but governed by different mechanisms. This study is among few that assess more than one metric of hydric physiology and that test the interactive effects of temperature and humidity. Such measurements will be essential for predictive models of activity and survival for animals under climate change.

The severity of preoperative anemia escalates risk of poor short-term outcomes after lumbar spine fusion

OBJECTIVE

To evaluate how preoperative anemia severity affects 90-day outcomes of spinal fusion surgery.

METHODS

A retrospective cohort study was conducted on adult lumbar fusion patients at a tertiary medical center. Patients were classified by World Health Organization anemia severity definitions for comparisons. Multivariate regression models were created to control for confounding variables, for all primary outcomes of transfusion requirements, non-home discharge, readmissions, complications, and length of stay.

RESULTS

A total of 2582 patients were included: 2.7% with moderate-severe anemia, 11.0% with mild anemia, and 86.3% without anemia. Moderate-severe patients had the longest hospital stay (5.03 days vs 4.14 and 3.59 days, p < 0.001) and highest risk of transfusion (52.2% vs 13.0% vs 2.69%, p < 0.001), non-home discharge (39.1% vs 27.8% vs 15.4%, p < 0.001), readmission (7.25% vs 5.99% vs 3.36%, p = 0.023), and complications (13.0% vs 9.51% vs 6.20%, p = 0.012). On multivariable logistic regression, both patients with mild and moderate-severe anemia had an increased risk of transfusion (OR: 37.3, p < 0.001; OR: 5.25, p < 0.001, respectively) and non-home discharge (OR: 2.00, p = 0.021; OR: 1.71, p = 0.001, respectively) compared to patients without anemia. Anemia severity was not independently associated with complications or 90-day readmission. On multivariable linear regression, mild anemia (β: 0.37, p = 0.001) and moderate-severe anemia (β: 1.07, p < 0.001) were independently associated with length of hospital stay.

CONCLUSION

Patients with moderate-severe preoperative anemia are at increased risk for longer length of stay, transfusions, and non-home discharge. Improved optimization of preoperative anemia may significantly reduce healthcare utilization, and surgeons should consider these risks in preoperative planning.

LEVEL OF EVIDENCE

III.

Evolution of hematocrit in burn patients as a marker of early fluid management during acute phase

OBJECTIVE

To evaluate the value of hematocrit for monitoring fluid resuscitation of burn patients in the acute phase of their care.

METHOD

We conducted a single-center retrospective study focused on patients admitted with a burn surface of more than 20 % of the total body surface area (TBSA) from 2014 to 2021. We investigated the relationship between the change in hematocrit and the volume administered for patient resuscitation. The change in hematocrit is the difference between an admission hematocrit and a second one taken between the eighth and twenty-fourth hour.

RESULTS

We included 230 patients with an average burn size of 39.1 ± 20.3 % TBSA, in 94.4 % by a thermal mechanism. The management seems to be in accordance with the current recommendations, with a volume administered during the first 24 h of 4.3 ± 2.5 ml/kg/ % BSA, allowing to obtain an hourly diuresis of 0.9 ± 0.7 ml/kg/h. We did not find any correlation between the pre-hospital volume administration and the hematocrit at admission (p = 0.36). Hematocrit decreased on average to -4.5 ± 8.1 % between admission and a control performed after the 8th hour. This decrease was weakly correlated with the volumes infused between the two samples (r2 =0.13, p < 0.001). A resuscitation above 5.2 ml/kg/ % Burn surface area is an independent factor for excess mortality.

CONCLUSION

Hematocrit or its variations in our limited data base appears to not reliably detect over-resuscitation, therefore it is possible that it may not be a relevant marker. These conclusions should be clarified in a multi-institutional prospective or real-world analysis to validate the findings and null hypothesis.

The associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents: a prospective cohort study

Uncontrolled pediatric hypertension may increase the risk of hypertension in adulthood. Several studies have reported an association between hematological parameters and blood pressure (BP) levels. However, epidemiologic evidence of this association in children and adolescents remains scarce. This study aims to explore the associations between hematological parameters and the incidence of prehypertension and hypertension in children and adolescents. This longitudinal study was conducted with 1368 participants aged 6-8 years from baseline visit to follow-up visit. Compared with participants from the normal blood pressure (BP) group, participants from the elevated BP group had significantly higher baseline red blood cell (RBC) counts, hemoglobin (Hb) counts and hematocrit (Hct) levels (all P < 0.001). A multilevel linear mixed model was conducted to analyze the relationship between hematological parameters and BP levels. The results suggested that SBP, DBP and MAP increased significantly with a quartile increase of levels of hematological parameters (all P < 0.05). Furthermore, a multilevel mixed logistic regression model was used to analyze the risk of per interquartile range increase in hematological parameters on the incidence of prehypertension and hypertension. The risk of prehypertension and hypertension incidence increased by (1.34 (95%CIs: 1.20, 1.50)), (1.38 (95%CIs: 1.24,1.54)), (1.33 (95%CIs: 1.19,1.50)), (1.14 (95%CIs: 1.03,1.26)) fold with a one-quartile increase in levels of RBC, Hb, Hct and Fe, respectively (all P < 0.05). This longitudinal study showed that hematological parameters were positively associated with BP levels in healthy children and adolescents, which excluded the effect of antihypertensive drugs on BP levels that often appeared in adults.

Relevant detection indicator of prethrombotic state in patients with primary hypertension

BACKGROUND

Hypertension is a common chronic disease that affects many people worldwide. Only a few reports related to the exploration of relevant indicators of the prethrombotic state in patients with primary hypertension (PH) in clinical settings were available.

AIM

To detect prethrombotic state-related indicators in patients with PH and analyze their differences in different patient populations to provide a laboratory basis for the clinical prevention and control of hypertensive thrombotic diseases.

METHODS

The general data of patients with PH who attended the Department of Cardiovascular Medicine, The First Affiliated Hospital of Jiangxi Medical College, from January 2022 to December 2022 were collected retrospectively. The patients were divided into three groups of 40 patients each according to the Grade of PH: Grade 1, Grade 2, and Grade 3 hypertension experimental group. The baseline data of 40 volunteers, who underwent physical examination in our hospital but were not diagnosed with PH during the same period, were included in the control group. The relevant indicators of prethrombotic state of the participants were compared, and mainly included inflammation-related indicators, hemorheology-related indicators, and coagulation function related indicators. The relationship between the aforementioned indicators and the progression of PH was analyzed.

RESULTS

No significant differences were observed in age, sex, diabetes mellitus, smoking history, drinking history, body mass index, New York Heart Association functional classification, or the course of hypertension among the four groups (P > 0.05). The expressions of high-sensitivity C-reactive protein (hs-CRP), thrombomodulin (TM), hematocrit (Hct), erythrocyte sedimentation rate (ESR), P-selectin on platelet surface (CD62P), and fibrinogen (FIB) in the control group were < Grade 1 hypertension group < Grade 2 hypertension group < Grade 3 hypertension group, and the expressions of platelet (PLT), activated partial thromboplastin time (APTT), prothrombin (PT), and plasma thrombin time (TT) in the control group was > Grade 1 hypertension group > Grade 2 hypertension group > Grade 3 hypertension group, and the difference was statistically significant (P < 0.05). The results of the multivariate logistic regression model showed that the expression of hs-CRP, TM, Hct, ESR, CD62P, PLT, APTT, PT, TT, and FIB in the included participants was related to the progression of PH. Among these, high expression of hs-CRP, TM, Hct, ESR, CD62P, APTT, PT, and TT, and low expression of PLT and FIB were risk factors for PH (OR > 1, P < 0.05). The results of the receiver operating characteristic curve analysis showed that the area under the curve of hs-CRP, TM, ESR, CD62P, APTT, PT, TT, and FIB for the prediction of PH were > 0.80, and the prediction value was ideal. Linear correlation analysis with bivariate Spearman showed that hs-CRP, TM, Hct, ESR, CD62P, APTT, PT, and TT were positively correlated with each other (r > 0, P < 0.05); PLT and FIB were negatively correlated with hs-CRP, TM, Hct, ESR, CD62P, APTT, PT, and TT (r < 0, P < 0.05); and PLT and FIB were positively correlated (r > 0, P < 0.05). Linear correlation analysis using bivariate Spearman showed that hs-CRP, TM, Hct, ESR, CD62P, and FIB were positively correlated with each other (r > 0, P < 0.05), whereas PLT, APTT, PT, and TT were negatively correlated with hs-CRP, TM, Hct, ESR, CD62P, and FIB (r < 0, P < 0.05). There was a positive correlation between PLT, APTT, PT, and TT (r > 0, P < 0.05).

CONCLUSION

The relevant indicators of the prethrombotic state in patients with PH, such as hs-CRP, TM, Hct, ESR, CD62P, PLT, APTT, PT, TT, and FIB, showed differences. High expression of hs-CRP, TM, Hct, ESR, CD62P, and FIB, and low expression of PLT, APTT, PT, and TT are the keys to the occurrence, progression, and thrombotic state of PH. Based on the above serum indicators' expression in patients, targeted interventions can be administered to patients with abnormal expression levels to control the progression of their disease and reduce the risk of developing a prethrombotic state.

Computational modeling of hemodynamics and risk of thrombosis in the left atrial appendage using patient-specific blood viscosity and boundary conditions at the mitral valve

Hemodynamics play a vital role for the risk of thrombosis in the left atrial appendage (LAA) and left atrium (LA) for patients with atrial fibrillation. Accurate prediction of hemodynamics in the LA can provide important guidance for assessing the risk of thrombosis in the LAA. Patient specificity is a crucial factor in representing the true hemodynamic fields. In this study, we investigated the effects of blood rheology (as a function of hematocrit and shear rate), as well as patient-specific mitral valve (MV) boundary conditions (MV area and velocity profiles measured by ultrasound) on the hemodynamics and thrombosis potential of the LAA. Four scenarios were setup with different degrees of patient specificity. Though using a constant blood viscosity can classify the thrombus and non-thrombus patients for all the hemodynamic indicators, the risk of thrombosis was underestimated for all patients compared with patient-specific viscosities. The results with least patient specificities showed that patients prone to thrombosis predicted by three hemodynamic indicators were inconsistent with clinical observations. Moreover, though patients had the same MV inlet flow rate, different MV models lead to different trends in the risk of thrombosis in different patients. We also found that endothelial cell activation potential and relative residence time can effectively distinguish thrombus and non-thrombus patients for all the scenarios, relatively insensitive to patient specificities. Overall, the findings of this study provide useful insights on patients-specific hemodynamic simulations of the LA.

Effects of delayed cord clamping at different time intervals in late preterm and term neonates: a randomized controlled trial

Delayed cord clamping (DCC) at delivery has well-recognized benefits; however, current scientific guidelines lack uniformity in its definition. This parallel-group, three-arm assessor-blinded randomized controlled trial compared the effects of three different timings of DCC at 30, 60, and 120 s on venous hematocrit and serum ferritin levels in late preterm and term neonates not requiring resuscitation. Eligible newborns (n = 204) were randomized to DCC 30 (n = 65), DCC 60 (n = 70), and DCC 120 (n = 69) groups immediately after delivery. The primary outcome variable was venous hematocrit at 24 ± 2 h. Secondary outcome variables were respiratory support, axillary temperature, vital parameters, incidences of polycythemia, neonatal hyperbilirubinemia (NNH), need and duration of phototherapy, and postpartum hemorrhage (PPH). Additionally, serum ferritin levels, the incidence of iron deficiency, exclusive breastfeeding (EBF) rate, and anthropometric parameters were assessed during post-discharge follow-up at 12 ± 2 weeks. Over one-third of the included mothers were anemic. DCC 120 was associated with a significant increase in the mean hematocrit by 2%, incidence of polycythemia, and duration of phototherapy, compared to DCC30 and DCC60; though the incidence of NNH and need for phototherapy was similar. No other serious neonatal or maternal adverse events including PPH were observed. No significant difference was documented in serum ferritin, incidences of iron deficiency, and growth parameters at 3 months even in the presence of a high EBF rate.   Conclusion: The standard recommendation of DCC at 30-60 s may be considered a safe and effective intervention in the busy settings of low-middle-income countries with a high prevalence of maternal anemia.   Trial registration: Clinical trial registry of India (CTRI/2021/10/037070). What is Known: • The benefits of delayed cord clamping (DCC) makes it an increasingly well-accepted practice in the delivery room. • However, uncertainty continues regarding the optimal timing of clamping; this may be of concern both in the neonate and the mother. What is New: • DCC at 120 s led to higher hematocrit, polycythemia and longer duration of phototherapy, without any difference in serum ferritin, and incidence of iron deficiency. • DCC at 30-60 s may be considered a safe and effective intervention in LMICs.

Factors affecting dialysis duration in children with Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome

BACKGROUND

Predicting disease severity can be informative for management of HUS. Dialysis requirement, volume depletion, elevated white blood cell counts, very young age, and use of antimotility agents are known factors associated with severe HUS.

METHODS

A retrospective cohort analysis was performed to identify factors associated with dialysis duration using electronic medical record and chart review of 76 children ≤ 18 years of age at presentation with STEC-HUS identified through billing data from July 2008 to April 2020 at James Whitcomb Riley Hospital for Children, Indiana University, Indiana.

RESULTS

Novel findings associated with prolonged dialysis duration were age ≥ 6 years old at presentation (p = 0.041) and lack of drop in platelets below 60,000/mm3 anytime during the illness (p = 0.015). In addition, children with NSAID exposure trended longer on dialysis: 15 days with vs. 10 days without (p = 0.117). Known risk factors for severe disease including elevated peak white blood cell (WBC) count and higher hematocrit at presentation were also associated with longer dialysis duration: children with peak WBC > 20,000/mm3 were on dialysis for 15 vs. 9.5 days (p = 0.002) and in children on dialysis ≥ 14 days hematocrit at presentation was 29.6% vs. 24.2% (p = 0.03). Children requiring dialysis for 20 days or longer were more likely to be on anti-hypertensive medications (p = 0.025) and have chronic kidney disease at 12-month follow up (p = 0.044).

CONCLUSIONS

Age ≥ 6, elevated WBC count > 20,000/mm3, higher hematocrit at presentation, lack of drop in platelets to < 60,000/mm3, and possibly NSAID exposure during illness are associated with longer dialysis duration in STEC-HUS. A higher resolution version of the Graphical abstract is available as Supplementary information.

Short-term effects of cold spells on hematocrit among adults in Nanjing, China: A distributed-lagged effect analysis

BACKGROUND

Previous studies have linked exposure to cold spells with cardiovascular diseases, however, underlying mechanisms remained to be understood. We aimed to explore the short-term effects of cold spells on hematocrit, a blood indicator associated with cardiovascular disease.

METHODS

Our study was performed among 50,538 participants (68,361 health examination records) who visited the health examination centers of Zhongda Hospital in Nanjing City, China, during the cold seasons from 2019 to 2021. Data on meteorology and air pollution were obtained from the China Meteorological Data Network and the Nanjing Ecological Environment Bureau, respectively. Cold spells in this study were defined as daily mean temperatures (Tmean) <3rd or 5th percentile with two or more consecutive days. Linear mixed-effect models combined with distributed lag nonlinear models were applied to estimate associations of cold spells with hematocrit.

RESULTS

Cold spells were found to be significantly correlated with increased hematocrit on lag 0 to 26 days. Moreover, the cumulative effects of cold spells on hematocrit remained significant at varying lag days. These single and cumulative effects were robust across different definitions of cold spells and conversions of hematocrit. For instance, cold spells (Tmean <3rd percentile) at lags 0, 0-1, and 0-27 days were significantly associated with 0.09 [95 % confidence interval (CI): 0.03, 0.15], 0.17 (95 % CI: 0.07, 0.28), and 3.71 (95 % CI: 3.06, 4.35) - unit (%) increases in original hematocrit, respectively. In subgroup analyses, stronger effects of cold spells on hematocrit were observed in females and participants aged 50 years or over.

CONCLUSION

Cold spells have significant immediate and longer-lagged effects (up to 26 days) on hematocrit. Females and individuals aged 50 years or over are more sensitive to cold spells. These findings might provide a new perspective for exploring the effects of cold spells on adverse cardiac events.

Tissue Oxygenation Around Capillaries: Effects of Hematocrit and Arteriole Oxygen Condition

Oxygen transfer in the microvasculature is a complex phenomenon that involves multiple physical and chemical processes and multiple media. Hematocrit, the volume fraction of red blood cells (RBCs) in blood, has direct influences on the blood flow as well as the oxygen supply in the microcirculation. On the one hand, a higher hematocrit means that more RBCs present in capillaries, and thus, more oxygen is available at the source end. On the other hand, the flow resistance increases with hematocrit, and therefore, the RBC motion becomes slower, which in turn reduces the influx of oxygen-rich RBCs entering capillaries. Such double roles of hematocrit have not been investigated adequately. Moreover, the oxygen-hemoglobin dissociation rate depends on the oxygen tension and hemoglobin saturation of the cytoplasm inside RBCs, and the dissociation kinetics exhibits a nonlinear fashion at different oxygen tensions. To understand how these factors and mechanisms interplay in the oxygen transport process, computational modeling and simulations are favorite since we have a good control of the system parameters and also we can access to the detailed information during the transport process. In this study, we conduct numerical simulations for the blood flow and RBC deformation along a capillary and the oxygen transfer from RBCs to the surrounding tissue. Different values for the hematocrit, arteriole oxygen tension, tissue metabolism rate and hemoglobin concentration and affinity are considered, and the simulated spatial and temporal variations of oxygen concentration are analyzed in conjunction with the nonlinear oxygen-hemoglobin reaction kinetics. Our results show that there are two competing mechanisms for the tissue oxygenation response to a hematocrit increases: the favorite effect of the higher RBC density and the negative effect of the slower RBC motion. Moreover, in the low oxygen situations with RBC oxygen tension less than 50 mmHg at capillary inlet, the reduced RBC velocity effect dominates, resulting in a decrease in tissue oxygenation at higher hematocrit. On the opposite, for RBC oxygen tension higher than 50 mmHg when entering the capillary, a higher hematocrit is beneficial to the tissue oxygenation. More interestingly, the pivoting arteriole oxygen tension at which the two competing mechanisms switch dominance on tissue oxygenation becomes lower for higher oxygen-hemoglobin affinity and lower hemoglobin concentration. This observation has also been analyzed based on the oxygen supply from RBCs and the oxygen-hemoglobin reaction kinetics. The results and discussions presented in this article could be helpful for a better understanding of oxygen transport in microcirculation.

The influence of blood composition and loading frequency on the behavior of embolus analogs

In cases of acute ischemic stroke (AIS), mechanical thrombectomy (MT) can be used to directly remove lodged thromboemboli. Despite improvements in patient outcomes, one of the key factors affecting MT success is the mechanical properties of the occlusive thrombus. Therefore, the goal of this study was to investigate the viscoelastic properties of embolus analogs (EAs) and determine the influence of EA hematocrit and loading frequency. Bovine blood EAs were created over a range of physiological hematocrits (0-60%) and cyclic uniaxial compression testing was performed at three loading frequencies to mimic in vivo loading conditions, followed by stress-relaxation testing. It was found that EAs exhibited behaviors typical of hyper-viscoelastic materials and that EA hematocrit played a large role in both EA stiffness and relaxation, with both parameters decreasing as hematocrit increased from 0 to 60%. The viscoelastic behavior of the EAs was also affected by the frequency at which they were loaded, with significant increases in peak stresses between the 0.5 and 2 Hz loaded EAs. Lower hematocrit EAs had very dense fibrin networks while the higher hematocrit EAs consisted of closely packed RBCs with little fibrin present. These results suggest that fibrin contributes to EA stiffness and relaxation behaviors while RBCs play a role in decreasing the overall viscous response and strain-rate dependency. An Ogden hyperelastic model was found to best reproduce the EA loading data while a 3-term Prony series was fit to the stress relaxation data. A hyper-viscoelastic modeling framework was then implemented combining the loading and stress-relaxation fits and the results could match the full cyclic loading data for EAs of varying hematocrit and loading frequency. The results of the experimental mechanical characterization and hyper-viscoelastic curve fitting can be incorporated in future modeling efforts to optimize mechanical thrombectomy for AIS patients.

Factors Affecting Day-to-Day Variations in Tacrolimus Concentration among Children and Young Adults Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Tacrolimus is widely used as prophylaxis for graft-versus-host disease (GVHD) in allogeneic stem cell transplantation (allo-HSCT). It has a narrow therapeutic index range; high tacrolimus concentrations are associated with toxicity, whereas low concentrations are associated with an increased risk of GVHD. Although dose adjustments based on therapeutic drug monitoring are performed, unexpected large variations in tacrolimus concentration are sometimes encountered. The available evidence suggests that the factors affecting tacrolimus concentration are not fully understood. This study was aimed primarily at investigating the factors affecting day-to-day variations in tacrolimus concentration in children and young adults who received continuous tacrolimus infusion after allo-HSCT. The secondary objective was to identify the factors causing large variations (>20%) in tacrolimus concentrations. This retrospective cohort study comprised 123 consecutive pediatric and young adult patients (age <25 years) who received continuous i.v. tacrolimus infusion after allo-HSCT at Shinshu University Hospital, Matsumoto, Japan, between January 2009 and December 2021. To compare day-to-day variations in tacrolimus concentration without consideration of the tacrolimus dose, 2 consecutive days when the tacrolimus dose was not changed were selected from between the first post-allo-HSCT day of a tacrolimus concentration >7 ng/mL and day 28 post-allo-HSCT. Subsequently, information for the subsequent 24 hours was collected along with the tacrolimus concentrations and hematocrit values. Tacrolimus concentration was determined using whole blood samples. Tacrolimus concentrations were significantly higher in patients who received red blood cell concentrate (RCC) transfusions (P < .0001) and methotrexate (P = .0162), patients with persistent fever (P = .0056), and patients with a decline in fever (P = .0003). In contrast, tacrolimus concentrations were significantly lower in patients who received platelet concentrate (PC) transfusions (P < .0001), who redeveloped fever (P = .0261), and who had a replaced tacrolimus administration route set (P = .0008). Variations in tacrolimus concentration were significantly correlated with variations in hematocrit (r = .556; P < .0001). Body weight (P < .0001), RCC transfusion (P < .0001), methotrexate use (P = .0333), persistent fever (P = .0150), and decline in fever (P = .0073) were associated with a sharp increase in tacrolimus concentration. In contrast, body weight (P < .0001), PC transfusion (P = .0025), and replacement of the tacrolimus administration route set (P = .0025) were associated with a sharp decrease in tacrolimus concentration. RCC and PC transfusions, fever, methotrexate administration, and replacement of the tacrolimus administration route set were independent factors affecting day-to-day variations in tacrolimus concentration. In addition to these factors, low body weight was a risk factor for both sharp increases and decreases in tacrolimus concentration. These findings suggest the need for better control of tacrolimus concentration using whole blood samples.

Gestational hemodilution as a putative risk factor for postpartum depression: A large-scale nationwide longitudinal cohort study

BACKGROUND

While anemia during pregnancy has been linked to increased postpartum depression (PPD) risk, longitudinal studies on the association between gestational hemodilution, represented by decreased hematocrit (Hct) during the transition from the 1st to 2nd trimester, and PPD risk, are scarce. The current study aimed to investigate this association in a nationwide cohort over the perinatal period.

METHODS

This retrospective cohort study included 104,715 women who gave birth between January 2008 and December 2015. The cohort was followed up for new-onset PPD during the year post birth and gestational hemodilution was assessed by the change in Hct levels (Δ: 2nd-1st trimester). The cohort was divided into three hemodilution groupings: maximal and minimal 10 % of mothers and intermediate 80 %. Multivariable regression analyses were performed to estimate the association between gestational hemodilution and PPD, adjusting for confounders.

RESULTS

Among the full cohort, 2.2 % (n = 2263) met the definition of new-onset PPD. Mothers with greater hemodilution had higher rates of PPD: 2.7 % (n = 269) in the maximal hemodilution group, 2.1 % (n = 1783) in the intermediate and 1.9 % (n = 211) in the minimal hemodilution group (p < 0.001). The maximal hemodilution group had higher rates of pre-gestational psychiatric disorders (p < 0.001) and higher adjusted risk for PPD [OR = 1.18, 95 % CI (1.04, 1.35)].

LIMITATIONS

Data on iron levels and supplementation were unavailable, thus it could not be adjusted for in the analysis.

CONCLUSIONS

Women in the top 10th percentile of gestational hemodilution may be at risk for PPD, justifying monitoring of gestational Hct as a biomarker for PPD.

Machine learning-based model for predicting the esophagogastric variceal bleeding risk in liver cirrhosis patients

BACKGROUND

Liver cirrhosis patients are at risk for esophagogastric variceal bleeding (EGVB). Herein, we aimed to estimate the EGVB risk in patients with liver cirrhosis using an artificial neural network (ANN).

METHODS

We included 999 liver cirrhosis patients hospitalized at the Beijing Ditan Hospital, Capital Medical University in the training cohort and 101 patients from Shuguang Hospital in the validation cohort. The factors independently affecting EGVB occurrence were determined via univariate analysis and used to develop an ANN model.

RESULTS

The 1-year cumulative EGVB incidence rates were 11.9 and 11.9% in the training and validation groups, respectively. A total of 12 independent risk factors, including gender, drinking and smoking history, decompensation, ascites, location and size of varices, alanine aminotransferase (ALT), γ-glutamyl transferase (GGT), hematocrit (HCT) and neutrophil-lymphocyte ratio (NLR) levels as well as red blood cell (RBC) count were evaluated and used to establish the ANN model, which estimated the 1-year EGVB risk. The ANN model had an area under the curve (AUC) of 0.959, which was significantly higher than the AUC for the North Italian Endoscopic Club (NIEC) (0.669) and revised North Italian Endoscopic Club (Rev-NIEC) indices (0.725) (all P <  0.001). Decision curve analyses revealed improved net benefits of the ANN compared to the NIEC and Rev-NIEC indices.

CONCLUSIONS

The ANN model accurately predicted the 1-year risk for EGVB in liver cirrhosis patients and might be used as a basis for risk-based EGVB surveillance strategies.

[Comment on article "Variability of hemoglobin and hematocrit determined in blood gas equipment"]

´The analysis of samples on different equipment may lead to variation between results; in the article "Variability of hemoglobin and hematocrit determined in blood gas equipment", the authors talk about the variability of hemoglobin and hematocrit between an automated hematology analyzer and an arterial blood gas analyzer. Information is requested on some aspects considered relevant to improve the understanding of the conclusions.

Hemoglobin normalization outperforms other methods for standardizing dried blood spot metabolomics: A comparative study

Dried blood spot (DBS) metabolomics has numerous applications in newborn health screening, exposomics, and biomonitoring of environmental chemicals in pregnant women and the elderly. However, accurate metabolite quantification is hindered by several challenges: notably the "hematocrit effect" and unknown blood-spotting volumes. Different techniques have been employed to overcome these issues but there is no consensus on the optimal normalization method for DBS metabolomics, and in some cases no normalization is used. We compared five normalization methods (hemoglobin (Hb), specific gravity (SG), protein, spot weight, potassium (K+)) to unnormalized data, and assessed sex-related differences in the DBS metabolome in 21 adults (group 1, n = 10 males, n = 11 females). The performance of each normalization method was evaluated using multiple criteria: (a) reduction of intragroup variation (pooled median absolute deviation, pooled estimate of variance, pooled coefficient of variation, NMDS and principal component analysis), (b) effect on differential metabolic analysis (dendrogram, heatmap, p-value distribution), and (c) influence on classification accuracy (partial least squares discriminant analysis, sparse partial least squares discriminant analysis error rates, receiver operating curve, random forest out of bag error rate). Our results revealed that Hb normalization outperformed all the other methods based on the three criteria and 13 different parameters; the performance of Hb was further demonstrated in an independent group of DBS from 18 neonates (group 2, n = 9 males, n = 9 females). Furthermore, we showed that SG and Hb are correlated in adults (rs = 0.86, p < 0.001), and validated this relationship in an independent group of 18 neonates and infants (group 3) (rs = 0.84, p < 0.001). Using the equation, SG = -0.4814Hb2 + 2.44Hb + 0.005, SG can be used as a surrogate for normalization by Hb. This is the first comparative study to concurrently evaluate multiple normalization methods for DBS metabolomics which will serve as a robust methodological platform for future environmental epidemiological studies.

Association of exposure to per- and polyfluoroalkyl substances with hemoglobin and hematocrit during pregnancy

BACKGROUND

Per- and polyfluoroalkyl substances (PFASs) are common environmental contaminants and are widely detected in humans. Previous studies have linked PFASs exposure to adverse birth outcomes. However, the association between maternal exposure to PFASs and hemoglobin (Hb) and hematocrit (HCT) remains unclear.

OBJECTIVES

We aimed to explore the relationship between PFASs exposure with Hb and HCT during pregnancy.

METHODS

The present birth cohort study included 1044 pregnant women from Wuhan, China. Maternal HCT and Hb were measured in the first, second and third trimesters, and 13 PFASs were detected in the cord sera. Mixed linear models and general linear regression were applied to analyze the association between each single PFASs and Hb and HCT. Weighted quantile sum (WQS) regressions were used to investigate the association between PFASs mixture and Hb and HCT during pregnancy.

RESULTS

In single-PFAS models, 10 PFASs were positively associated with HCT and Hb across pregnancy (a 10-fold increase in PFASs was associated with 1.47-3.54 % change in HCT and 1.46-3.20 % change in Hb (All P-FDR < 0.05). In addition, Hb and HCT were more positively related to PFASs in the second and third trimesters rather than the first trimester. The association between PFASs exposure and maternal HCT and Hb was not significant in the iron supplementation group, whereas significant in the non-iron supplementation group. A significant interaction between iron supplementation and non-iron supplementation was also detected. WQS regressions showed that perfluorononanoic acid (PFNA) and perfluorohexane sulfonate (PFHxS) contributed most to the association between PFASs and HCT and Hb in the second and third trimesters, respectively.

CONCLUSION

Maternal PFASs exposure was positive with serum Hb and HCT. Moreover, maternal iron supplementation may play a modifying effect in influencing the relationship between PFASs and HCT and Hb.

Comparison of the red blood cell indices based on accuracy, sensitivity, and specificity to predict one-year mortality in heart failure patients

BACKGROUND

Various investigations have specified the role of each RBC indices separately [including hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red blood cell distribution width (RDW)] to predict the prognosis of acute heart failure (AHF) patients. However, in the current study, these variables were compared based on accuracy, sensitivity, and specificity to determine the best prognostic factor.

METHODS

Of 734 heart failure patients referred to the emergency department, 400 cases were enrolled based on the inclusion and exclusion criteria. Data of them were documented, and patients were followed for one year. Eventually, the association of clinical variables and RBC indices with one-year mortality was explored.

RESULTS

The study included 226 (56%) men and 174 (44%) women with a median age of 66 years. Body Mass Index (HR 1.098, p = 0.016), Hb (HR 0.728, p = 0.024), HTC (HR 0.875, p = 0.066), MCHC (HR 0.795, p = 0.037), and RDW-CV (HR 1.174, p = 0.006) were confirmed as predictors of long-term mortality. Despite confirming the predictive role of these variables by ROC curves, their sensitivity and specificity were reported as follows: [72% and 50% for Hb], [75% and 52% for  HCT], [88% and 27% for MCHC], and [49% and 81% for RDW]. In addition, stratified groups of patients, based on normal cut-off values obtained from scientific literature, had significantly different survival in Kaplan-Meier analyses.

CONCLUSION

Whilst proving the predictive role of Hb,  HCT, MCHC, and RDW in AHF patients, the most sensitive measurement was MCHC and the most specific one was RDW; therefore, these variables should be considered for risk stratification purposes of AHF patients in daily clinical practice.

Low-dose CT from myocardial perfusion SPECT/CT allows the detection of anemia in preoperative patients

BACKGROUND

To assess whether low-dose CT for attenuation correction of myocardial perfusion single-photon emission computed tomography (SPECT) allows for identification of anemic patients and grading anemia severity.

METHODS AND RESULTS

Patients who underwent a preoperative blood-test and low-dose CT scan, as a part of a cardiac SPECT exam, between 01 January 2015 and 31 December 2017 were enrolled in this retrospective study. Hemoglobin (Hb) levels and hematocrit were derived from clinical records. CT images were visually assessed (qualitative analysis) for the detection of inter-ventricular septum sign (IVSS) and aortic rim sign (ARS) and quantitative analysis were performed. The diagnostic accuracy for detecting anemia was compared using Hb values as the standard of reference. A total of 229 patients were included (110 with anemia; 57 mild; 46 moderate; 7 severe). The AUC of IVSS and ARS were 0.830 and 0.669, respectively (p<0.0001). The quantitative analysis outperformed ARS and IVSS; (AUC of 0.893, p=0.29). The optimal anemia cut-off using Youden index was 4.5 HU.

CONCLUSION

Quantitative analysis derived from low-dose CT images, as a part of cardiac SPECT exams, have a diagnostic accuracy similar to that of hematocrit for the detection of anemia and may allow discriminating different anemia severities.

How can sodium-glucose cotransporter 2 inhibitors stimulate erythrocytosis in patients who are iron-deficient? Implications for understanding iron homeostasis in heart failure

Many patients with heart failure have an iron-deficient state, which can limit erythropoiesis in erythroid precursors and ATP production in cardiomyocytes. Yet, treatment with sodium-glucose cotransporter 2 (SGLT2) inhibitors produces consistent increases in haemoglobin and haematocrit, even in patients who are iron-deficient before treatment, and this effect remains unattenuated throughout treatment even though SGLT2 inhibitors further aggravate biomarkers of iron deficiency. Heart failure is often accompanied by systemic inflammation, which activates hepcidin, thus impairing the duodenal absorption of iron and the release of iron from macrophages and hepatocytes, leading to a decline in circulating iron. Inflammation and oxidative stress also promote the synthesis of ferritin and suppress ferritinophagy, thus impairing the release of intracellular iron stores and leading to the depletion of bioreactive cytosolic Fe2+ . By alleviating inflammation and oxidative stress, SGLT2 inhibitors down-regulate hepcidin, upregulate transferrin receptor protein 1 and reduce ferritin; the net result is to increase the levels of cytosolic Fe2+ available to mitochondria, thus enabling the synthesis of heme (in erythroid precursors) and ATP (in cardiomyocytes). The finding that SGLT2 inhibitors can induce erythrocytosis without iron supplementation suggests that the abnormalities in iron diagnostic tests in patients with mild-to-moderate heart failure are likely to be functional, rather than absolute, that is, they are related to inflammation-mediated trapping of iron by hepcidin and ferritin, which is reversed by treatment with SGLT2 inhibitors. An increase in bioreactive cytosolic Fe2+ is also likely to augment mitochondrial production of ATP in cardiomyocytes, thus retarding the progression of heart failure. These effects on iron metabolism are consistent with (i) proteomics analyses of placebo-controlled trials, which have shown that biomarkers of iron homeostasis represent the most consistent effect of SGLT2 inhibitors; and (ii) statistical mediation analyses, which have reported striking parallelism of the effect of SGLT2 inhibitors to promote erythrocytosis and reduce heart failure events.

Evaluation of lung ultrasound to detect volume overload in children undergoing dialysis

BACKGROUND

Lung ultrasound is a well-established technique to assess extravascular lung water, a proxy for volume status, in the adult population. Despite its utility, the data are limited supporting the use of ultrasound to evaluate fluid volume status among pediatric patients. Our study uses a simplified ultrasound protocol to evaluate changes in extravascular lung water, represented by b-lines, among pediatric patients undergoing hemodialysis.

METHODS

This prospective single-center study included children from birth to 18 years of age. The number of b-lines per ml/kg of fluid removed was compared prior to, at the midpoint, and following termination of dialysis. An 8-zone protocol was utilized, and b-lines were correlated to hemoconcentration measured by the CRIT-LINE® hematocrit.

RESULTS

Six patients with a total of 26 hemodialysis sessions were included in this study. The b-line measurements post-dialysis were 2.27 (p < 0.001; 94%CI -3.31, -1.22) lower relative to pre-dialysis. The number of b-lines was reduced by 1.69 (p < 0.001; -2.58, -0.80) between pre-dialysis and at the midpoint of dialysis and by 0.58 (p = 0.001; -0.90, -0.24) between the midpoint of dialysis and post-dialysis. A 1 mL/kg fluid loss correlated to a decrease in the original b-lines by 0.079. An inverse relationship (r = -0.54; 95% CI: -0.72, -0.34; p < 0.001) was noted between the b-lines and the patients' hematocrit levels.

CONCLUSIONS

A simplified 8-zone ultrasound protocol can assess fluid volume change in real time and correlates with hematocrit levels obtained throughout dialysis. This provides a valuable method for monitoring fluid status in volume overloaded patient populations. A higher resolution version of the Graphical abstract is available as Supplementary information.

Effects of rapid fluid infusion on hemoglobin concentration: a systematic review and meta-analysis

Background

Rapid fluid administration may decrease hemoglobin concentration (Hb) by a diluting effect, which could limit the increase in oxygen delivery (DO₂) expected with a positive response to fluid challenge in critically ill patients. Our aim was to quantify the decrease in Hb after rapid fluid administration.

Methods

Our protocol was registered in PROSPERO (CRD42020165146). We searched PubMed, the Cochrane Database, and Embase from inception until February 15, 2022. We selected studies that reported Hb before and after rapid fluid administration (bolus fluid given over less than 120 min) with crystalloids and/or colloids in adults. Exclusion criteria were studies that included bleeding patients, or used transfusions or extracorporeal circulation procedures. Studies were divided according to whether they involved non-acutely ill or acutely ill (surgical/trauma, sepsis, circulatory shock or severe hypovolemia, and mixed conditions) subjects. The mean Hb difference and, where reported, the DO₂ difference before and after fluid administration were extracted. Meta-analyses were conducted to assess differences in Hb before and after rapid fluid administration in all subjects and across subgroups. Random-effect models, meta-regressions and subgroup analyses were performed for meta-analyses. Risk of bias was assessed using the Cochrane Risk of Bias Assessment Tool. Inconsistency among trial results was assessed using the I² statistic.

Results

Sixty-five studies met our inclusion criteria (40 in non-acutely ill and 25 in acutely ill subjects), with a total of 2794 participants. Risk of bias was assessed as “low” for randomized controlled trials (RCTs) and ‘low to moderate’ for non-RCTs. Across 63 studies suitable for meta-analysis, the Hb decreased significantly by a mean of 1.33 g/dL [95% CI − 1.45 to − 1.12; p < 0.001; I² = 96.88] after fluid administration: in non-acutely ill subjects, the mean decrease was 1.56 g/dL [95% CI − 1.69 to − 1.42; p < 0.001; I² = 96.71] and in acutely ill patients 0.84 g/dL [95% CI − 1.03 to − 0.64; p = 0.033; I² = 92.91]. The decrease in Hb was less marked in patients with sepsis than in other acutely ill patients. The DO₂ decreased significantly in fluid non-responders with a significant decrease in Hb.

Conclusions

Hb decreased consistently after rapid fluid administration with moderate certainty of evidence. This effect may limit the positive effects of fluid challenges on DO₂ and thus on tissue oxygenation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04191-x.

Effect of hypobaric hypoxia on hematological parameters related to oxygen transport, blood volume and oxygen consumption in adolescent endurance-training athletes

Objective

To analyze the effect of altitude on hematological and cardiorespiratory variables in adolescent athletes participating in aerobic disciplines.

Methods

21 females and 89 males participated in the study. All were adolescent elite athletes engaged in endurance sports (skating, running and cycling) belonging to two groups: permanent residents in either low altitude (LA, 966 m) or moderate altitude (MA, 2640 m). Hematocrit (Hct), hemoglobin concentration ([Hb]), total hemoglobin mass (Hbt), blood, plasma and erythrocyte volumes (BV, PV and EV), VO₂peak and other cardiorespiratory parameters were evaluated.

Results

Sex differences were evident both in LA and HA skating practitioners, the males having higher significant values than the females in oxygen transport-related hematological parameters and VO₂peak. The effect of altitude residence was also observed in Hct, [Hb], Hbt and EV with increased (14%–18%) values in the hematological parameters and higher EV (5%–24%). These results matched the significantly higher values of VO₂peak measured in MA residents. However, BV and PV did not show differences between LA and MA residents in any case. Sports discipline influenced neither the hematological variables nor most of the cardiorespiratory parameters.

Conclusions

LA and MA adolescent skaters showed sex differences in hematological variables. Endurance-trained male adolescent residents at MA had an increased erythropoietic response and a higher VO₂peak compared to their counterparts residing and training at LA. These responses are similar in the three aerobic sports studied, indicating that the variables described are highly sensitive to hypoxia irrespective of the sports discipline.

Serum levels of matrix metalloproteinases as prognostic markers for severe dengue with plasma leakage

BACKGROUND

Plasma leakage is a major pathogenic manifestation of severe dengue and is a precursor of life-threatening complications associated with dengue. Accumulating evidence indicates the role of Matrix Metalloproteinases (MMPs) in mediating vascular permeability and plasma leakage following induction by the dengue virus. This study aims to investigate the utility of MMP-2, MMP-3, and MMP-9 in predicting the severity of dengue infection and further explore the relationship of these markers with the pathogenic factors associated with plasma leakage.

METHODS

The dengue-positive subjects were classified into mild and severe dengue groups based on the manifestation of warning signs. The samples in each group and healthy controls were quantified for basic laboratory characteristics. The levels of MMP-2, MMP-3, MMP-9, and Macrophage migration inhibitory factor (MIF) were estimated in all serum samples using a multiplex bead-based assay.

RESULTS

MMP-2 and MMP-9 were markedly elevated in severe dengue patients compared to mild dengue patients and healthy controls. No alteration in the circulating levels of MMP-3 was observed between the study groups. ROC curve analysis indicated that MMP-2 and MMP-9 exhibited good potential for predicting severe dengue. Notably, an increase in MMP-9 was associated with increased MIF and Hematocrit levels in severe dengue patients.

CONCLUSION

MMP-2 and MMP-9 could serve as prognostic biomarkers for severe dengue. These findings also identify the association of MMP-9 with markers of plasma leakage, thereby encouraging further studies to explore the therapeutic potential of targeting MMP-9 in managing plasma leakage in severe dengue.

The hematological impact of umbilical cord milking versus delayed cord clamping in premature neonates: a randomized controlled trial

BACKGROUND

The hematological impact of umbilical cord milking (UCM) was compared to that of delayed cord clamping (DCC) as a faster placental transfusion technique for preterm neonates (between 24 and 34 + 6 weeks gestation). A comparison of important neonatal morbidities was also made.

METHODS

This was an open-label randomized trial conducted from June 8, 2017, to April 22, 2019. Two hundred patients with preterm deliveries (24 and 34 + 6 weeks gestation) were assigned to the DCC or UCM group at random at a ratio of 1:1. The study power was 80% for a difference in the hematocrit value of 3% and Hb value of one gram, and an alpha error of 0.05.

RESULTS

The following variables were analyzed in the comparison of UCM vs. DCC: first draw hemoglobin: 17.0 ± 1.9 vs. 16.8 ± 1.8 gm/dl (95% CI -0.75-0.29, P 0.383); first draw hematocrit: 55.6 ± 6.4 vs. 55.2 ± 6.4% (95% CI -2.18-1.38, P 0.659); peak hematocrit: 56.9 ± 6.4 vs. 56.3 ± 6.7% (95% CI -2.41-1.26, P 0.537); the need for respiratory assistance (47% vs. 30%, P 0.020), inotropes (16% vs. 6%, P 0.040), and blood transfusion (26% vs. 12%, P 0.018); and the occurrence of intraventricular hemorrhage (9% vs. 5%, P 0.407), necrotizing enterocolitis (6% vs. 2%, P 0.279), sepsis (25% vs. 15%, P 0.111), and neonatal death (13% vs. 4%, P 0.40).

CONCLUSION

UCM facilitated a rapid transfer of placental blood equivalent to that of DCC for premature neonates. However, it resulted in increased rates of interventions and morbidities, especially in extremely preterm neonates.

TRIAL REGISTRATION

The clinical trial was registered on May 10, 2017, with registration number (NCT03147846).

Utilizing umbilical cord blood - Minimizing blood sampling and pain in healthy infants at risk for polycythemia

BACKGROUND

Exposure to pain in early life was associated with long term consequences, therefore strategies for minimizing painful procedures in newborns should be employed. The utility and reliability of cord blood CBC was demonstrated before, however data regarding use of cord blood in healthy infants at risk for polycythemia are lacking.

METHODS

A single-center, paired-sampling prospective laboratory study including all healthy asymptomatic infants born after 36 weeks gestation who were SGA (<2500 g), LGA (>4000 g), or born to mothers with diabetes in pregnancy. Blood count indices were compared between umbilical and neonatal capillary or venous blood samples. In order to predict cut-off values for neonatal polycythemia using umbilical hematocrit, receiver operator curves (ROC) were plotted.

RESULTS

Paired samples were collected from 433 infants. Mean gestational age and birth-weight were 39.0 ± 1.3 weeks and 3489 ± 682 g. Hemoglobin, hematocrit and WBC values were lower in cord blood compared to neonatal, but PLT count was higher. Pearson r showed only modest correlation between peripheral capillary and umbilical or venous Hct - 0.35 (p < 0.001), and 0.44 (p < 0.001), respectively. In order to try and capture clinically significant polycythemia ROC was plotted for hematocrit >70% and <40%. In our cohort, using the calculated cutoff values (>51% and <35%) could have resulted in a decrease of 72% of neonatal blood draws.

CONCLUSION

This analysis should be interpreted with caution, as currently it cannot support the routine use of umbilical samples' hematocrits for making treatment decision in newborns at risk for polycythemia. Further larger studies are needed.

A novel Vascular Leak Index identifies sepsis patients with a higher risk for in-hospital death and fluid accumulation

Purpose

Sepsis is a leading cause of morbidity and mortality worldwide and is characterized by vascular leak. Treatment for sepsis, specifically intravenous fluids, may worsen deterioration in the context of vascular leak. We therefore sought to quantify vascular leak in sepsis patients to guide fluid resuscitation.

Methods

We performed a retrospective cohort study of sepsis patients in four ICU databases in North America, Europe, and Asia. We developed an intuitive vascular leak index (VLI) and explored the relationship between VLI and in-hospital death and fluid balance using generalized additive models (GAM).

Results

Using a GAM, we found that increased VLI is associated with an increased risk of in-hospital death. Patients with a VLI in the highest quartile (Q4), across the four datasets, had a 1.61–2.31 times increased odds of dying in the hospital compared to patients with a VLI in the lowest quartile (Q1). VLI Q2 and Q3 were also associated with increased odds of dying. The relationship between VLI, treated as a continuous variable, and in-hospital death and fluid balance was statistically significant in the three datasets with large sample sizes. Specifically, we observed that as VLI increased, there was increase in the risk for in-hospital death and 36–84 h fluid balance.

Conclusions

Our VLI identifies groups of patients who may be at higher risk for in-hospital death or for fluid accumulation. This relationship persisted in models developed to control for severity of illness and chronic comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03968-4.

Varying aerobic capacity in relation to breeding stage and reproductive success in giant petrels (Macronectes spp.)

Reproduction, and parental care in particular, are among the most energy-demanding activities within the annual cycle of adult birds. Parents that cannot meet the metabolic demands and other physiological costs of raising offspring may opt to abandon chicks in favour of self-maintenance and future reproduction. Recent work examining reproductive trade-offs in birds revealed an important role of oxygen carrying capacity in mediating variation in parental effort. This study explores the aerobic factors underlying the success or failure of parental care in two closely-related petrel species during their breeding season on Bird Island, South Georgia: northern giant petrels (Macronectes halli) and southern giant petrels (M. giganteus). Failed breeders of both sexes and species had significantly lower hematocrit levels (by 5.48 ± 0.64%) than successful breeders, and reticulocyte counts also tended to be lower in failed males, consistent with the hypothesis that parental care and workload depend on aerobic capacity. We discuss these results in relation to differences in the foraging ecology of both species and sexes.

Simultaneous electrical online estimation of changes in blood hematocrit and temperature in cardiopulmonary bypass

Two equations have been developed from multi-frequency measurements of blood impedance Z_b for a simultaneous electrical online estimation of changes in blood hematocrit ΔH [%] and temperatures ΔT [K] in cardiopulmonary bypass (CPB). Z_b of fixed blood volumes at varying H and T were measured by an impedance analyzer and changes in blood conductivity σ_b and relative permittivity ε_b computed. Correlation analysis were based on changes in σ_b with H or T at f = 1 MHz while H and T equations were developed by correlating changes in ε_b with H and T at dual frequencies of f = 1 MHz and f = 10 MHz which best capture blood plasma Z_p and red blood cell cytoplasm Z_cyt impedances respectively. Results show high correlations between σ_b and H (R² = 0.987) or σ_b and T (R² = 0.9959) indicating dependence of the electrical parameters of blood on its H and T. Based on computed ε_b, changes in blood hematocrit ΔH and temperature ΔT at a given time t are estimated as ΔH(t) = 1.7298Δε_b (f = 1 MHz) - 1.0669Δε_b (f = 10 MHz) and ΔT(t) = -2.186Δε_b (f = 1 MHz) + 2.13Δε_b (f = 10 MHz). When applied to a CPB during a canine mitral valve plasty, ΔH and ΔT had correlations of R² = 0.9992 and R² = 0.966 against H and T respectively as measured by conventional devices.

Simultaneous multiparameter whole blood hemostasis assessment using a carbon nanotube-paper composite capacitance sensor

Rapid and accurate clinical assessment of hemostasis is essential for managing patients who undergo invasive procedures, experience hemorrhages, or receive antithrombotic therapies. Hemostasis encompasses an ensemble of interactions between the cellular and non-cellular blood components, but current devices assess only partial aspects of this complex process. In this work, we describe the development of a new approach to simultaneously evaluate coagulation function, platelet count or function, and hematocrit using a carbon nanotube-paper composite (CPC) capacitance sensor. CPC capacitance response to blood clotting at 1.3 MHz provided three sensing parameters with distinctive sensitivities towards multiple clotting elements. Whole blood-based hemostasis assessments were conducted to demonstrate the potential utility of the developed sensor for various hemostatic conditions, including pathological conditions, such as hemophilia and thrombocytopenia. Results showed good agreements when compared to a conventional thromboelastography. Overall, the presented CPC capacitance sensor is a promising new biomedical device for convenient non-contact whole-blood based comprehensive hemostasis evaluation.

Diagnostic accuracy of first and early second trimester multiple biomarkers for prediction of gestational diabetes mellitus: a multivariate longitudinal approach

BACKGROUND

Gestational Diabetes Mellitus (GDM) is an underlying cause of maternal and newborn morbidity and mortality all around the world. Timely diagnosis of GDM plays an important role in reducing its adverse consequences and burden. This study aimed to determine diagnostic accuracy of multiple indicators in complete blood count (CBC) test for early prediction of GDM.

METHODS

In this prospective cohort study, the data from 600 pregnant women was analyzed. In the study sample, the two-step approach was utilized for the diagnosis of GDM at 24-28 weeks of gestation. We also used the repeated measures of hemoglobin (Hb), hematocrit (Hct), fasting blood sugar (FBS) and red blood cell count (RBC) in the first and early second trimesters of pregnancy as the longitudinal multiple indicators for early diagnosis of GDM. The classification of pregnant women to GDM and non-GDM groups was performed using a statistical technique based on the random-effects modeling framework.

RESULTS

Among the sample, 49 women (8.2%) were diagnosed with GDM. In the first and early second trimester of pregnancy, the mean HcT, Hb and FBS of women with GDM was significantly higher than non-GDMs (P < 0.001). The concurrent use of multiple longitudinal data from HcT, Hb, RBC and FBS in the first and early second trimester of pregnancy resulted in a sensitivity, specificity and area under the curve (AUC) of 87%, 70% and 83%, respectively, for early prediction of GDM.

CONCLUSIONS

In general, our findings showed that the concurrent use of repeated measures data on Hct, Hb, FBS and RBC in the first and early second trimester of pregnancy might be utilized as an acceptable tool to predict GDM earlier in pregnancy.