Corticosterone negative feedback is weaker during spring vs. autumn migration in a songbird (Junco hyemalis)

Birds face many challenges during seasonal migrations and must make important decisions about whether to accelerate, maintain, or delay travel to their final destinations. Spring migration is likely more challenging than autumn migration as spring journeys are completed more quickly and weather conditions are harsher during this time. These differential challenges may be reflected in the endocrine stress response, as the hypothalamic-pituitary-adrenal (HPA) axis is important for both daily energetic needs and coping with stressors. Indeed, most avian studies have found that both baseline and stress-induced corticosterone (CORT) levels tend to be higher in spring migrants than in autumn migrants. We hypothesized that CORT negative feedback efficacy also differs across the season, and is likely weaker during times of year when birds must be most sensitive to stressors. We therefore predicted that CORT negative feedback efficacy would be weaker during spring vs. autumn migration as spring migrants are more likely to encounter situations where they must decide whether to turn back or delay their travel. We examined male dark-eyed juncos (Junco hyemalis) during their spring and autumn stopovers in Fargo, ND, USA. Our prediction was met as we did find that negative feedback efficacy was weaker during spring vs. autumn, although we notably did not find any seasonal differences in baseline and stress-induced CORT. We also found that spring migrants were heavier, had greater subcutaneous fat stores, and had slightly higher hematocrit compared to autumn migrants. These findings suggest that CORT negative feedback sensitivity may help migrating birds effectively cope with the differential challenges of autumn and spring migration.

Evaluation of the efficacy of ivermectin against Theileria orientalis infection in grazing cattle

BACKGROUND

Raising cattle on pastures is known to be beneficial for animal welfare and cost reduction. However, grazing is associated with the risk of contracting tick-borne diseases, such as theileriosis. Here, the efficacy of ivermectin against these diseases and associated clinical symptoms were evaluated.

RESULTS

A total of 68 cattle from a grazing cattle farm were selected and divided into two groups: the control group (17 cattle) with no preventive treatment and the ivermectin-treated group (51 cattle) in which cattle were treated with pour-on ivermectin prior to grazing. The infection rates of Theileria orientalis and the red blood cell (RBC) profile (e.g., RBC count, hematocrit value, and hemoglobin concentration) were compared in the spring (before grazing) and summer (during grazing) between the two groups. Based on PCR amplification of the major piroplasm surface protein (MPSP) gene, 12 cattle were positive for T. orientalis infection. Phylogenetic analysis revealed that the isolates identified in this study consisted of three MPSP types (1, 2, and 7). The T. orientalis infection rate in the control group during grazing was 3-fold higher than that in the ivermectin-treated group. Moreover, differences in RBC parameters during grazing were greater in the control group than in the ivermectin-treated group. In particular, the hematocrit value was significantly reduced in the control group.

CONCLUSIONS

The results of this study demonstrated that ivermectin had protective effects against T. orientalis infection and RBC hemolysis in grazing cattle.

Dynamic Contrast Optical Coherence Tomography reveals laminar microvascular hemodynamics in the mouse neocortex in vivo

Studies of flow-metabolism coupling often presume that microvessel architecture is a surrogate for blood flow. To test this assumption, we introduce an in vivo Dynamic Contrast Optical Coherence Tomography (DyC-OCT) method to quantify layer-resolved microvascular blood flow and volume across the full depth of the mouse neocortex, where the angioarchitecture has been previously described. First, we cross-validate average DyC-OCT cortical flow against conventional Doppler OCT flow. Next, with laminar DyC-OCT, we discover that layer 4 consistently exhibits the highest microvascular blood flow, approximately two-fold higher than the outer cortical layers. While flow differences between layers are well-explained by microvascular volume and density, flow differences between subjects are better explained by transit time. Finally, from layer-resolved tracer enhancement, we also infer that microvascular hematocrit increases in deep cortical layers, consistent with predictions of plasma skimming. Altogether, our results show that while the cortical blood supply derives mainly from the pial surface, laminar hemodynamics ensure that the energetic needs of individual cortical layers are met. The laminar trends reported here provide data that links predictions based on the cortical angioarchitecture to cerebrovascular physiology in vivo.

[Clinical significance of pulse contour cardiac output monitoring technology in guiding fluid replacement during shock stage of extensive burn]

Objective: To explore the guiding significance of pulse contour cardiac output (PiCCO) monitoring technology in the treatment of fluid replacement during shock stage of extensive burn in clinic. Methods: Sixty-five patients with extensive burn hospitalized in our unit from January 2014 to December 2018, conforming to the inclusion criteria, were recruited to conduct a prospective controlled research. According to the order of admission, 35 odd-numbered patients and 30 even-numbered patients were enrolled in routine rehydration group (25 males and 10 females) and PiCCO monitoring rehydration group (21 males and 9 females) respectively, with the age of (48±9) and (44±8) years respectively. All patients of the two groups were rehydrated according to the rehydration formula of the Third Military Medical University during shock stage. The rehydration speed was adjusted in routine rehydration group according to the general indexes of shock such as central venous pressure, mean arterial pressure, heart rate, respiratory rate, urine volume, and clinical symptoms of patients. PiCCO monitoring was performed in patients of PiCCO monitoring rehydration group, and the global end-diastolic volume index combined with the other relevant indicators of PiCCO were used to guide rehydration on the basis of the monitoring indicators of routine rehydration group. The heart rates and positive fluid balance volumes at post injury hour (PIH) 8, 16, 24, 32, 40, 48, 56, 64, and 72, the diuretic dosage at PIH 48 and 72, the total fluid replacement volumes, urine volumes, blood lactic acid, platelet count, and hematocrit at PIH 24, 48, and 72, the length of intensive care unit (ICU) stay, and the incidence of complications and death within 28 days after injury were compared between patients in the two groups. Data were processed with analysis of variance for repeated measurement, t test, Bonferroni correction, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. Results: The heart rates of patients in the two groups were similar at PIH 8, 16, 24, 32, 40, 48, and 56 (t=0.775, 1.388, 2.511, 2.203, 1.654, 2.303, 1.808, P>0.05), and the heart rates of patients in PiCCO monitoring rehydration group at PIH 64 and 72 were obviously lower than those of routine rehydration group (t=3.229, 3.357, P<0.05 or P<0.01). The positive fluid balance volumes of patients in the two groups were similar at PIH 8, 16, 40, and 56 (t=0.768, 1.670, 2.134, 2.791, P>0.05), and the positive fluid balance volumes of patients in PiCCO monitoring rehydration group at PIH 24, 32, 48, 64, and 72 were obviously less than those of routine rehydration group (t=3.364, 4.047, 2.930, 2.950, 2.976, P<0.05 or P<0.01). The amount of diuretics used by patients in the two groups was similar at PIH 48 and 72 (Z=-0.697, -1.239, P>0.05). The total fluid replacement volumes of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were (13 864±4 241), (9 532±2 272), and (8 480±2 180) mL, respectively, obviously more than those in routine rehydration group [(10 388±2 445), (8 095±1 720), and (7 059±1 297) mL, respectively, t=-3.970, -2.848, -3.137, P<0.05 or P<0.01]. The urine volumes of patients in the two groups at PIH 24 were close (t=-1.027, P>0.05). The urine volumes of patients in PiCCO monitoring rehydration group at PIH 48 and 72 were (3 051±702) and (3 202±624) mL respectively, obviously more than those in routine rehydration group [(2 401±588) and (2 582±624) mL respectively, t=-4.062, -4.001, P<0.01]. The levels of blood lactate acid of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were obviously lower than those in routine rehydration group (t=4.758, 6.101, 3.938, P<0.01). At PIH 24 and 48, the values of the platelet count of patients in PiCCO monitoring rehydration group were obviously higher than those in routine rehydration group (t=-2.853, -2.499, P<0.05), and the values of hematocrit of patients in PiCCO monitoring rehydration group were obviously lower than those in routine rehydration group (t=2.698, 4.167, P<0.05 or P<0.01). Both the platelet count and hematocrit of patients in the two groups were similar at PIH 72 (t=-1.363, 0.476, P>0.05). The length of ICU stay of patients in PiCCO monitoring rehydration group was obviously shorter than that of routine rehydration group (t=2.184, P<0.05). Within 28 days after injury, the incidence of complications of patients in routine rehydration group was obviously higher than that in PiCCO monitoring rehydration group (P<0.05), while the mortality rate of patients in routine rehydration group was similar to that in PiCCO monitoring rehydration group (P>0.05). Conclusions: The application of PiCCO monitoring technology in monitoring fluid replacement in patients with extensive burn can quickly correct shock, reduce the occurrence of organ complications caused by improper fluid replacement, and shorten the length of ICU stay, which is of great significance in guiding the treatment of burn shock.

Testosterone Therapy: An Assessment of the Clinical Consequences of Changes in Hematocrit and Blood Flow Characteristics

INTRODUCTION

Clinical guidelines indicate that hematocrit should be monitored during testosterone replacement therapy (TTh), with action taken if a level of 0.54 is exceeded.

AIM

To consider the extent of changes in hematocrit and putative effects on viscosity, blood flow, and mortality rates after TTh.

METHODS

We focused on literature describing benefits and possible pitfalls of TTh, including increased hematocrit. We used data from the BLAST RCT to determine change in hematocrit after 30 weeks of TTh and describe a clinical case showing the need for monitoring. We consider the validity of the current hematocrit cutoff value at which TTh may be modified. Ways in which hematocrit alters blood flow in the micro- and macro-vasculature are also considered.

MAIN OUTCOME MEASURES

The following measures were assessed: (i) change in hematocrit, (ii) corresponding actions taken in clinical practice, and (iii) possible blood flow changes following change in hematocrit.

RESULTS

Analysis of data from the BLAST RCT showed a significant increase in mean hematocrit of 0.01, the increase greater in men with lower baseline values. Although 0 of 61 men given TTh breached the suggested cutoff of 0.54 after 30 weeks, a clinical case demonstrates the need to monitor hematocrit. An association between hematocrit and morbidity and mortality appears likely but not proven and may be evident only in patient subgroups. The consequences of an increased hematocrit may be mediated by alterations in blood viscosity, oxygen delivery, and flow. Their relative impact may vary in different vascular beds.

CONCLUSIONS

TTh can effect an increased hematocrit via poorly understood mechanisms and may have harmful effects on blood flow that differ in patient subgroups. At present, there appears no scientific basis for using a hematocrit of 0.54 to modify TTh; other values may be more appropriate in particular patient groups. König CS, Balabani S, Hackett GI, et al. Testosterone Therapy: An Assessment of the Clinical Consequences of Changes in Hematocrit and Blood Flow Characteristics. Sex Med Rev 2019;7:650-660.

In vitro analysis of blood flow in a microvascular network with realistic geometry

In vitro blood flow was measured in a polydimethysiloxane micro channel to reflect the complex geometry of a microvascular network. Flow rates were determined from the velocities of tracer particles moving along the center line of the flow channel, and the flow rates of two working fluids were then compared: water and blood. In some bifurcating channels, the measured flow rate showed that the effects of bifurcation in the apparent viscosity depend on the hematocrit, such that the flow rate in the daughter channel with the higher (lower) flow rate was lower (higher) for blood than for water. The measured flow rates in other bifurcating channels reflected effects from the surrounding flow channels acting as bypasses, which tended to balance out the effects of bifurcation.

Use of Hematocrit for Short-Term Prognosis of Patients with Traumatic Brain Injury After Decompressive Craniectomy

OBJECTIVE

To discuss the effects of the hematocrit (Hct) in patients with traumatic brain injury after decompressive craniectomy (DC).

METHODS

Demographic data, inspection and treatment procedures, and 30-day prognosis were obtained for 158 patients with head injury who underwent unilateral DC in our hospital between January 2013 and June 2018. Uni- and multivariate logistic regression was applied to analyze independent risk factors for 30-day outcome. The quantitative analysis of postoperative Hct, ΔHct (postoperative Hct minus initial Hct), and their combination for the prognosis of patients with TBI was displayed graphically using receiver operating characteristic (ROC) curves. Multiple linear regression was used to explore factors influencing postoperative Hct and ΔHct.

RESULTS

Short-term mortality was 29.7%. Uni- and multivariate logistic regression analysis showed that age (odds ratio [OR], 1.064; P = 0.024), Glasgow Coma Scale score (OR, 0.711; P = 0.027), Injury Severity Score (ISS) (OR, 1.156; P = 0.047), midline shift in millimeters (OR, 1.809; P <0.001), postoperative Hct (OR, 0.743; P = 0.001), and ΔHct (OR, 1.242; P =0.048) were independent risk factors for short-term death. In ROC curves, a combination of postoperative Hct and ΔHct showed the highest sensitivity (77.5%) and highest specificity (89.4%). When using this combination to predict prognosis, we could achieve an accuracy of 94.5%. ISS (β = -0.172, P = 0.022), initial Hct (β = 0.243, P = 0.001), principal hematoma location (β = -2.628, P < 0.001), hours of operation (β = -0.884, P = 0.048), and colloid quantity (β = -0.002, P = 0.001) were independent contributing factors for ΔHct, which was similar to postoperative Hct.

CONCLUSIONS

A combination of postoperative Hct and ΔHct could better predict short-term survival of patients with TBI. Developing an appropriate treatment strategy to increase postoperative Hct and reduce the ΔHct may be good for the short-term prognosis of patients with TBI after DC.

Hematology reference intervals for transgender adults on stable hormone therapy

BACKGROUND

The complete blood count (CBC) is a cornerstone of patient care. Several of the normal values for the components of the CBC differ by sex and, therefore, male-specific and female-specific reference intervals are required to interpret these laboratory results. Transgender individuals are often prescribed hormone therapy to affirm their gender, with resulting serum hormone concentrations similar to those of cisgender individuals. Gender-specific reference intervals for transgender men and women have not been established for any laboratory measurements, including hematology. We established clinically relevant hematological reference intervals for transgender individuals receiving stable hormone therapy.

METHODS

Healthy transgender individuals prescribed testosterone (n = 79) or estrogen (n = 93) for ≥12 months were recruited from internal medicine and primary care clinics that specialize in transgender medical care. Concentrations for hemoglobin, hematocrit, MCV, MCHC, and RDWCV, as well as counts for red cells, white cells, and platelets, were evaluated. Results were interpreted in reference to the overall distribution of values and relative to serum estradiol and total testosterone concentrations. Calculated reference intervals were compared to established cisgender reference intervals.

RESULTS

Regardless of serum hormone concentration, individuals prescribed testosterone or estrogen had hematology parameters that were not clinically different from cisgender males and females, respectively.

CONCLUSION

The hematology parameters for transgender men and women receiving stable hormone therapy should be evaluated against the cisgender male and cisgender female reference ranges, respectively and does not require concurrent sex hormone analysis. Care providers can utilize this observation to aid in interpretation of hematology laboratory values for transgender people.

Utility of Hounsfield unit and hematocrit values in the diagnosis of acute venous sinus thrombosis in unenhanced brain CTs in the pediatric population

BACKGROUND

Cerebral venous sinus thrombosis (CVST) is a recognized cause of childhood and neonatal stroke with high morbidity and mortality and a challenging diagnosis in the pediatric population.

OBJECTIVE

We hypothesize that measuring Hounsfield units (HU) of blood in venous sinuses is a more reliable method to diagnose CVST and that normalizing the measured HU in relation to the patient's hematocrit levels may further improve detection of CVST in the pediatric population.

MATERIALS AND METHODS

We performed a retrospective chart review of 15 pediatric patients with acute CVST and 31 control patients. Regions of interest (ROIs) were plotted to measure HU values within the venous sinuses of each patient. Hounsfield unit to hematocrit (HU:Hct) ratios were also calculated. In patients with CVST, HU values were determined in thrombosed and non-thrombosed venous sinuses. Statistical analysis was performed to calculate the differences between patient and control groups and to determine optimal cutoff values for HU and HU:Hct measurements in diagnosing CVST on non-contrast brain computed tomography (CT).

RESULTS

A statistically significant difference in sinus attenuation and HU:Hct ratio was found between thrombosed (66.2±5.3 HU, 1.96±0.4) and non-thrombosed sinuses (47.2±4.5 HU, 1.38±0.25) in the patient group (P<0.0001), with the average attenuation difference being 19 HU. A statistically significant difference was also found between thrombosed sinuses in the patient group and sinuses (48.9±3.13 HU, 1.3±0.12) in the control group (P<0.0001).

CONCLUSION

Optimal cutoff values of 58 HU and HU:Hct ratios of 1.4 lead to sensitivities of 100% in diagnosing CVST.

Phenotypic flexibility in respiratory traits is associated with improved aerial respiration in an amphibious fish out of water

Amphibious fishes have evolved multiple adaptive strategies for respiring out of water, but there has been less focus on reversible plasticity. We tested the hypothesis that when amphibious fishes leave water, enhanced respiratory performance on land is the result of rapid functional phenotypic flexibility of respiratory traits. We acclimated four isogenic strains of Kryptolebias marmoratus to air for 0, 1, 3 or 7 days. We compared respiratory performance out of water with traits linked to the O₂ cascade. Aerial O₂ consumption rate was measured over a step-wise decrease in O₂ levels. There were significant differences between strains, but time out of water had the largest impact on measured parameters. K ryptolebias marmoratus had improved respiratory performance [lower aerial critical oxygen tension (P _crit), higher regulation index (RI)] after only 1 day of air exposure, and these changes were strongly associated with the change in hematocrit and dorsal cutaneous angiogenesis. Additionally, we found that 1 h of air exposure induced the expression of four angiogenesis-associated genes - vegfa, angpt2, pecam-1 and efna1 - in the skin. After 7 days in air, respiratory traits were not significantly linked to the variation in either aerial P _crit or RI. Overall, our data indicate that there are two phases involved in the enhancement of aerial respiration: an initial rapid response (1 day) and a delayed response (7 days). We found evidence for the hypothesis that respiratory performance on land in amphibious fishes is the result of rapid flexibility in both O₂ uptake and O₂ carrying capacity.

More efficient exchange of sickle red blood cells can be achieved by exchanging the densest red blood cells: An ex vivo proof of concept study

BACKGROUND

In sickle cell disease (SCD), red blood cells (RBCs) containing hemoglobin S can be denser than RBCs containing wild-type hemoglobin, especially when dehydrated. We hypothesize that targeting denser RBCs during red blood cell (RBC) exchange for SCD could result in more efficient removal of dehydrated, sickled RBCs and preservation of non-sickled RBCs.

STUDY DESIGN AND METHODS

Waste products from RBC exchanges for SCD were used as "simulated patients". One RBC volume was exchanged using ABO-compatible blood. The apheresis instrument was programmed to exchange the entire RBC layer by indicating the hematocrit (control), or the bottom half by indicating the hematocrit was half the hematocrit (experimental), with or without subsequent transfusion. Hemoglobin S levels, and complete blood counts were measured.

RESULTS

Hemoglobin S levels were lower after the modified versus control RBC exchange (post-RBC exchange mean 4.96% and 11.27%); total hemoglobin S amounts were also lower (mean 19.27 and 58.29 mL of RBCs). Mean RBC density decreased after the modified RBC exchange by 8.86%. Hematocrit decreased in the modified RBC exchange by 36.37%, with partial correction by direct transfusion following a truncated RBC exchange.

CONCLUSIONS

Targeting denser RBCs in RBC exchange enhanced hemoglobin S removal and decreased RBC density. Further development of this ex vivo model could potentially allow for: 1) improved reduction in hemoglobin S levels (allowing for longer periods between RBC exchange or maintained lower levels), or 2) achievement of previous goal hemoglobin S levels with fewer donor units (reducing alloimmunization risk and improving blood utilization).

The potential impact of hematocrit correction on evaluation of tacrolimus target exposure in pediatric kidney transplant patients

BACKGROUND

Tacrolimus is an important immunosuppressive agent with high intra- and inter-individual pharmacokinetic variability and a narrow therapeutic index. As tacrolimus extensively accumulates in erythrocytes, hematocrit is a key factor in the interpretation of tacrolimus whole blood concentrations. However, as hematocrit values in pediatric kidney transplant patients are highly variable after kidney transplantation, translating whole blood concentration targets without taking hematocrit into consideration is theoretically incorrect. The aim of this study is to evaluate the potential impact of hematocrit correction on tacrolimus target exposure in pediatric kidney transplant patients.

METHODS

Data were obtained from 36 pediatric kidney transplant patients. Two hundred fifty-five tacrolimus whole blood samples were available, together responsible for 36 area under the concentration-time curves (AUCs) and trough concentrations. First, hematocrit corrected concentrations were derived using a formula describing the relationship between whole blood concentrations, hematocrit, and plasma concentrations. Subsequently, target exposure was evaluated using the converted plasma target concentrations. Ultimately, differences in interpretation of target exposure were identified and evaluated.

RESULTS

In total, 92% of our patients had lower hematocrit (median 0.29) than the reference value of adult kidney transplant patients. A different evaluation of target exposure for either trough level, AUC, or both was defined in 42% of our patients, when applying hematocrit corrected concentrations.

CONCLUSION

A critical role for hematocrit in therapeutic drug monitoring of tacrolimus in pediatric kidney transplant patients is suggested in this study. Therefore, we believe that hematocrit correction could be a step towards improvement of tacrolimus dose individualization.

Preoperative hematocrit on early prosthetic joint infection and deep venous thrombosis rates in primary total hip arthroplasty: A database study

BACKGROUND

Total hip arthroplasty (THA) is a very successful surgery in restoring a patient's quality of life. Infection is a devastating complication of THA. Many risks factors for infection in THA have been identified but little is known of the effect by preoperative hematocrit.

PURPOSE

We aimed to evaluate the effect of preoperative hematocrit on early superficial site infections, deep infections, and deep organ space infections.

METHODS

Our study cohort included patients undergoing a THA in the ACS National Surgical Quality Improvement Program database from 2006 to 2015. We conducted a multivariate logistic regression analysis to evaluate an association between preoperative hematocrit and infection controlling for patients demographics and known risk factors.

RESULTS

A total of 98,869 patients were identified in this study. Of these, 702 (0.71%) developed a superficial site infection, 314 (0.32%) a deep infection, and 226 (0.23%) an organ space infection. Our results suggested a significant increased risk of deep infection (OR = 2.38, p = 0.0120) and organ space infection (OR = 3.05, p = 0.0234) in patients with lower preoperative hematocrit (<41). In addition, patients with lower preoperative hematocrit had higher chance to receive postoperative transfusion (OR = 2.93, p < 0.0001). However, no significant associations between preoperative hematocrit and superficial site infections (p = 0.8554), wound dehiscence (p = 0.0660) and DVT (p = 0.9236) were detected.

CONCLUSION

Low preoperative hematocrit is associated with increased risk of deep, organ space infections, and postoperative transfusion in THA, but not with superficial site infections, wound dehiscence and DVT.

Delayed Cord Clamping versus Early Cord Clamping in Elective Cesarean Section: A Randomized Controlled Trial

BACKGROUND

Delaying cord clamping is recommended in order to assure placental transfusion. However, the evidence on cord management in elective cesarean section (CS) is limited.

OBJECTIVE

To compare delayed cord clamping (DCC) with early cord clamping (ECC) with regard to postnatal adaptation in neonates born through elective CS.

METHODS

All neonates born ≥39 weeks' gestation born through elective CS were assigned to either the DCC or the ECC arm at a 1:1 ratio according to a computer-generated, randomized sequence. The primary outcome was the hematocrit at day 2 of life. Secondary outcomes included: preductal oxygen saturation and heart rate during the first 10 min of life; transcutaneous bilirubin at day 3; and neonatal blood pressures in the first 3 days of life. Additional outcomes included: time to first spontaneous breath; temperature at admission to normal nursery; weight at discharge; and maternal blood losses.

RESULTS

Eighty neonates were randomized to the DCC (n = 40) or the ECC (n = 40) arm. The hematocrit at day 2 was significantly higher in the DCC arm than in the ECC arm (mean difference: 6%; 95% CI 3-8; p < 0.0001). The secondary outcome measures were not statistically different between the two arms. No infants needed phototherapy for hyperbilirubinemia during their hospital stay.

CONCLUSIONS

Delaying cord clamping beyond 60 s increases the hematocrit at day 2 in neonates born through elective CS, without affecting maternal blood losses. Our findings suggest that DCC should be recommended in elective CS, but further studies are warranted to assess long-term outcomes.

Missing data treatments matter: an analysis of multiple imputation for anterior cervical discectomy and fusion procedures

BACKGROUND CONTEXT

The presence of missing data is a limitation of large datasets, including the National Surgical Quality Improvement Program (NSQIP). In addressing this issue, most studies use complete case analysis, which excludes cases with missing data, thus potentially introducing selection bias. Multiple imputation, a statistically rigorous approach that approximates missing data and preserves sample size, may be an improvement over complete case analysis.

PURPOSE

The present study aims to evaluate the impact of using multiple imputation in comparison with complete case analysis for assessing the associations between preoperative laboratory values and adverse outcomes following anterior cervical discectomy and fusion (ACDF) procedures.

STUDY DESIGN/SETTING

This is a retrospective review of prospectively collected data.

PATIENT SAMPLE

Patients undergoing one-level ACDF were identified in NSQIP 2012-2015.

OUTCOME MEASURES

Perioperative adverse outcome variables assessed included the occurrence of any adverse event, severe adverse events, and hospital readmission.

METHODS

Missing preoperative albumin and hematocrit values were handled using complete case analysis and multiple imputation. These preoperative laboratory levels were then tested for associations with 30-day postoperative outcomes using logistic regression.

RESULTS

A total of 11,999 patients were included. Of this cohort, 63.5% of patients had missing preoperative albumin and 9.9% had missing preoperative hematocrit. When using complete case analysis, only 4,311 patients were studied. The removed patients were significantly younger, healthier, of a common body mass index, and male. Logistic regression analysis failed to identify either preoperative hypoalbuminemia or preoperative anemia as significantly associated with adverse outcomes. When employing multiple imputation, all 11,999 patients were included. Preoperative hypoalbuminemia was significantly associated with the occurrence of any adverse event and severe adverse events. Preoperative anemia was significantly associated with the occurrence of any adverse event, severe adverse events, and hospital readmission.

CONCLUSIONS

Multiple imputation is a rigorous statistical procedure that is being increasingly used to address missing values in large datasets. Using this technique for ACDF avoided the loss of cases that may have affected the representativeness and power of the study and led to different results than complete case analysis. Multiple imputation should be considered for future spine studies.

Comparative analysis of blood parameters of the erythrocyte lineage between patients with chronic periodontitis and healthy patients: Results obtained from a meta-analysis

Objective Quantitatively evaluate blood parameters of the erythrocyte lineage in patients with chronic periodontitis and healthy controls by means of a meta-analysis. Material and methods A review of literature was performed in the scientific databases for studies published before September 2016. The abstracts were evaluated and the extraction of data performed by two examiners. The parameters assessed were: hemoglobin levels, number of circulating red blood cells, hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration in patients with chronic periodontitis and healthy controls. The calculations were obtained through the statistical software Review Manager version 5.3, with calculation of Mean Difference, heterogeneity (I²) and funnel plot with P < 0.05. Results Nine case/control studies composed the results with 342 patients with chronic periodontitis and 359 healthy controls. There was a significant decrease in hemoglobin levels (MD = -1.60, 95% CI: -2.72, -0.48, P = 0.005) and number of circulating red blood cells (MD = -0.51, 95% CI: -0.78, -0.24, P = 0.0002), hematocrit (MD = -4.41, IC 95%: -7.13, -1.68, P = 0.002), mean corpuscular hemoglobin (MD = -0.80; IC 95%: -1.38, -0,22, P = 0.007) and mean corpuscular hemoglobin concentration (MD = -0.93, IC 95%: -1.63, -0.23, P = 0.009) in patients with chronic periodontitis when compared to healthy controls. No publication bias was found through the funnel plot asymmetry. Conclusion There is an associated of the reduction of hematological parameters (such as levels of hemoglobin and circulating red blood cells, hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration) to patients with chronic periodontitis.

[Mediating effect of hemoglobin and hematocrit on the association between alcohol consumption and blood pressure among middle-aged and elderly male residents in Guangzhou]

Objective: To explore the mediating effect of hemoglobin (Hb) and hematocrit (HCT) on the association between alcohol consumption and blood pressure, and provide evidence for the prevention and control of alcohol-attributed hypertension. Methods: 1 091 male (age >50 years old) participants with drinking habit were selected from the Guangzhou biobank cohort study (GBCS). Mediation analysis was used to evaluate the mediating effect of Hb and HCT on the association of alcohol consumption (unit/day) with systolic blood pressure (SBP), diastolic blood pressure(DBP), pulse pressure(PP) and mean arterial pressure (MAP). Results: After adjusting for age, body mass index, education level, personal annual income, smoking, occupation and physical activity, the associations of alcohol consumption with SBP, DBP, PP and MAP were partly mediated by Hb, the proportion of mediating effect was 11.8% (95%CI 4.8%-24.7%), 15.3% (95%CI 6.5%-32.0%), 8.4% (95%CI 2.2%-22.5%) and 13.5% (95%CI 5.9%-27.5%), respectively. The associations of alcohol consumption with SBP, DBP, and MAP were also partly mediated by HCT, the proportion of mediating effect was 6.3% (95%CI 1.0%-16.0%), 8.7% (95%CI 1.4%-21.4%), and 7.5% (95%CI 1.0%-18.6%), respectively. Conclusion: There is a significant mediating effect of Hb and HCT on the association between alcohol consumption and blood pressure. Besides efforts on alcohol control, the potential effects of alcohol-induced increase on Hb and HCT, which might also increase the blood pressure, need to be considered to achieve optimal monitoring and prevention of alcohol-related hypertension.

[Influence of propofol dose and blood components on duration of electrical seizures in electroconvulsive therapy]

BACKGROUND AND OBJECTIVES

Propofol is commonly employed as a hypnotic agent to perform electroconvulsive therapy, but it exhibits also anticonvulsant properties. The main objective was to study the effect of the weight-adjusted dose of propofol on duration of the electrical seizure. Secondary objectives were to study the effect of absolute dose of propofol on duration of electrical seizure, the effect of both absolute and weight-adjusted doses on values of bispectral index, and the influence of blood chemistry on anticonvulsant effect.

METHODS

After approval of the Institutional Review Board, a retrospective chart review was performed of all patients who underwent at least one electroconvulsive therapy session. Multiple lineal regression analysis adjusted for potential confounders was employed to explore the effect of propofol dosage on values of bispectral index and on duration of seizure; bivariate correlation analyses were previously performed to identify variables fulfilling confounding criteria, specifically values of Spearman's rho >0.10. Results of regression analysis were expressed as B coefficient with its 95% confident interval.

RESULTS

76 patients received 631 acute phase sessions. Propofol showed a statistically significant negative effect on duration of seizure (specifically a reduction of 4.081s for every mg.kg^-1 of propofol; CI95%: -7906 to -0.255, p=0.037) but not on bispectral index values. Slight anemia and hypoalbuminemia were very infrequent conditions, and the anticonvulsant effect was not influenced by these parameters.

CONCLUSIONS

Propofol weight-adjusted dose is negatively related to duration of seizures. It should be carefully titrated when employed to perform electroconvulsive therapy.

Correlation of hematocrit and Apgar scores in newborns of women with hypertensive disorders in pregnancy

OBJECTIVES

To compare the incidence of polycythemia in newborns of women with hypertensive disorders in pregnancy (HDP) with those of normotensive mothers, to determine the incidence of perinatal stress using Apgar scores and to correlate hematocrit with Apgar scores in these newborn.

STUDY DESIGN

This was a hospital-based comparative study conducted in the University of Port Harcourt Teaching Hospital, Nigeria.

MAIN OUTCOME MEASURES

Apgar scores of 200 newborns- 100 from mothers with HDP (case group) and 100 from normotensive mothers (control group)- were taken at 1st and 5th minute of birth and cord blood samples collected to determine hematocrit. The subjects were categorized into polycythemic and non polycythemic using a hematocrit ≥65%.

RESULTS

Eight percent of newborns of women with HDP had polycythemia while none of the controls did. Apgar scores in the case group with and without polycythemia at one-minute were 4.1±1.8 and 6.6±2.1, respectively and at 5 minutes were 6.9±1.7 and 8.5±1.4 respectively. Hematocrit correlated positively with Apgar scores (both at one and five minutes) in cases without polycythemia (r = 0.221, p = 0.034 and r = 0.255, p = 0.014). Hematocrit of polycythemic newborns did not correlate with Apgar scores (r = -0.287, p = 0.491 and r = -0.436, p = 0.281).

CONCLUSION

The incidence of polycythemia is significantly higher in newborns of women with HDP and these polycythemic neonates had a significantly higher incidence of birth asphyxia. Therefore, birth outcome as determined by Apgar score is influenced by hematocrit.

Hyponatremia in Acute Heart Failure in Relation to Hematocrit Levels: Clinical Relevance and Prognostic Implication

BACKGROUND

Hyponatremia is the most common electrolyte abnormality found in hospitalized patients with acute heart failure (AHF) and is related to poor prognosis. This study sought to evaluate: (1) the different prognostic impact of dilutional versus depletional hyponatremia, evaluating short- and long-term outcome; (2) the relationship between both types of hyponatremia and intravenous furosemide dose, renal function changes, and persistent congestion at discharge.

METHODS

This retrospective single-center study included 233 consecutive patients with a primary diagnosis of AHF. Hyponatremia was defined as serum sodium < 135 mEq/L, which could be either dilutional (hematocrit < 35%) or depletional (hematocrit ≥35%). Persistent congestion was defined as a congestion score ≥2 at discharge. Patients were followed 180 days for occurrence of death or rehospitalization for AHF.

RESULTS

Hyponatremia was present in 68/233 patients with 27 cases classified as dilutional hyponatremia versus 41 as depletional. The proportion of patients with persistent congestion was higher in the dilutional hyponatremia group, but similar in the depletional hyponatremia group (52 vs. 81 vs. 58%; p = 0.02). After adjustment for important baseline characteristics, dilutional hyponatremia was significantly associated with the risk of death or rehospitalization for AHF at 60 days (HR 2.17 [1.08-4.37]; p = 0.03) and 180 days (HR 1.88 [1.10-3.21]; p = 0.02). In contrast, depletional hyponatremia was only significantly associated with the same endpoint at 180 days (HR 1.64 [1.05-2.57]; p = 0.03).

CONCLUSIONS

Low hematocrit levels in AHF patients with hyponatremia characterize a population that is more difficult to decongest and has poor clinical outcome. In contrast, patients with hyponatremia but normal hematocrit are better decongested and have better short-term outcome.

Design and Utility of a Point-of-Care Microfluidic Platform to Assess Hematocrit and Blood Coagulation

Purpose—

To develop a small volume whole blood analyzer capable of measuring the hematocrit and coagulation kinetics of whole blood.

Methods and Results—

A co-planar microfluidic chamber designed to facilitate self-driven capillary action across an internal electrical chip was developed and used to measure the electric parameters of whole human blood that had been anticoagulated or allowed to clot. To promote blood clotting, select chip surfaces were coated with a prothrombin time (PT) reagent containing lipidated tissue factor (TF), which activates the extrinsic pathway of coagulation to promote thrombin generation and fibrin formation. Whole human blood was added to the microfluidic device, and voltage changes within the platform were measured and interpreted using basic resistor-capacitor (RC) circuit and fluid dynamics theory. Upon wetting of the sensing zone, a circuit between two co-planar electrodes within the sensing zone was closed to generate a rapid voltage drop from baseline. The voltage then rose due to sedimentation of red blood cells (RBC) in the sensing zone. For anticoagulated blood samples, the time for the voltage to return to baseline was dependent on hematocrit. In the presence of coagulation, the initiation of fibrin formation in the presence of the PT reagent prevented the return of voltage to baseline due to the reduced packing of RBCs in the sensing zone.

Conclusions—

The technology presented in this study has potential for monitoring the hematocrit and coagulation parameters of patient samples using a small volume of whole blood, suggesting it may hold clinical utility as a point-of-care test.

Comparison of the effect of breast pump stimulation and oxytocin administration on the length of the third stage of labor, postpartum hemorrhage, and anemia: a randomized controlled trial

BACKGROUND

This study aimed to compare the effect of breast pump stimulation with that of oxytocin administration regarding the duration of the third stage of labor, postpartum hemorrhage, and anemia after delivery.

METHODS

In this study, 108 women were randomly assigned to two groups of breast pump stimulation (n = 54) and oxytocin administration (n = 54). Women in the breast stimulation group received breast pump stimulation (10 min intermittently for each breast with a negative pressure of 250 mmHg), while the women in the oxytocin (control) group received an infusion of 30 IU oxytocin in 1000 mL of Ringer's serum with a maximum rate of 10 mL infusion per min after delivery. The duration of the third stage of labor, blood loss during the third stage of labor and 24 h after delivery, hemoglobin and hematocrit (before and 24 h after delivery), after-birth pain, and the number of breastfeedings during the 24 h after delivery were recorded. The data were analyzed using the chi-square test, independent t-test, and Wilcoxon test.

RESULTS

The mean duration of the third stage was 5 ± 1.97 and 5.4 ± 2.5 min in the breast stimulation and women that received intravenous oxytocin respectively (p = 0.75). Most participants had mild postpartum hemorrhage (98.1 and 96.2% in the breast stimulation and women that received intravenous oxytocin, respectively, p = 0.99). Although hemoglobin and hematocrit levels significantly decreased in both groups 24 h after delivery, there was no significant difference between both groups regarding both parameters. After-birth pain was significantly lower and the number of breastfeeding during the 24 h after delivery was significantly more in the breast stimulation group compared to the control group.

CONCLUSIONS

Our results demonstrated no differences between breast pump stimulation and oxytocin administration regarding the duration of the third stage of labor, postpartum hemorrhage, anaemia, after-birth pain, and the number of breastfeedings during the 24 h after delivery.

TRIAL REGISTRATION NUMBER

The study protocol was registered in the Iranian Randomized Controlled Trial Registry (Ref. No.: IRCT2015050722146N1 ; Registration date: 2015-11-04). The study was registered prospectively and the enrollment date was 23/8/2015.

Toxicological effects of trichlorfon on hematological and biochemical parameters in Cyprinus carpio L. following thermal stress

Trichlorfon is a moderately toxic organophosphate pesticide that is widely used in aquaculture. This study investigated the effects of trichlorfon on hematological parameters, biochemical factors, and stress reaction in Cyprinus carpio L. The fish were exposed to acute concentrations of trichlorfon (0, 0.5, 1.0, 2.0, and 4.0 mg L^-1) at 25 °C and 15 °C for 1 and 2 weeks, after which several parameters were evaluated to assess the effects of the pesticide. Significant decreases were observed in red blood cell (RBC) Count, hemoglobin (Hb) level, hematocrit (Ht), and plasma protein levels after each exposure period. In contrast, notable increases in mean corpuscular volume (MCV), mean cell hemoglobin (MCH), calcium, and glucose levels were observed in the trichlorfon-treated groups. Additionally, there were significant increases in the plasma levels of glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT), and alkaline phosphatase (ALP) following the exposure to trichlorfon. Furthermore, the results showed a relationship between toxic stress and increment in HSP70 and cytochrome P450 1A (CYP1A) expression over time. Ht, MCV, MCH, and the value of other biochemical parameters were quite lower at 15 °C than their corresponding values were at 25 °C, which indicated the decreased physical activity at 15 °C. The results of the present work indicate that acute exposure to trichlorfon and thermal stimulus could damage erythropoietic tissue. Additionally, hepatocytes function and physiological mechanisms could be impaired. Ht, glucose, GOT, GPT, HSP70, and CYP1A levels might be useful biomarkers of trichlorfon toxicity in contaminated aquatic ecosystems.

Importance of standardizing timing of hematocrit measurement when using cardiovascular magnetic resonance to calculate myocardial extracellular volume (ECV) based on pre- and post-contrast T1 mapping

BACKGROUND

Cardiovascular magnetic resonance (CMR) can be used to calculate myocardial extracellular volume fraction (ECV) by relating the longitudinal relaxation rate in blood and myocardium before and after contrast-injection to hematocrit (Hct) in blood. Hematocrit is known to vary with body posture, which could affect the calculations of ECV. The aim of this study was to test the hypothesis that there is a significant increase in calculated ECV values if the Hct is sampled after the CMR examination in supine position compared to when the patient arrives at the MR department.

METHODS

Forty-three consecutive patients including various pathologies as well as normal findings were included in the study. Venous blood samples were drawn upon arrival to the MR department and directly after the examination with the patient remaining in supine position. A Modified Look-Locker Inversion recovery (MOLLI) protocol was used to acquire mid-ventricular short-axis images before and after contrast injection from which motion-corrected T1 maps were derived and ECV was calculated.

RESULTS

Hematocrit decreased from 44.0 ± 3.7% before to 40.6 ± 4.0% after the CMR examination (p < 0.001). This resulted in a change in calculated ECV from 24.7 ± 3.8% before to 26.2 ± 4.2% after the CMR examination (p < 0.001). All patients decreased in Hct after the CMR examination compared to before except for two patients whose Hct remained the same.

CONCLUSION

Variability in CMR-derived myocardial ECV can be reduced by standardizing the timing of Hct measurement relative to the CMR examination. Thus, a standardized acquisition of blood sample for Hct after the CMR examination, when the patient is still in supine position, would increase the precision of ECV measurements.

Increase serum cortisol in young guinea pig offspring in response to maternal iron deficiency

Iron deficiency (ID) has been reported as a risk factor in the pathology of attention-deficit/hyperactivity disorder, although the mechanisms seem unclear. Previous results from our research group showed that guinea pig offspring born from ID dams were significantly more active in the Open Field Test than the controls. This behavior could potentially be associated to stress. We therefore hypothesized that maternal iron deficiency (MID) elevates the offspring serum cortisol, a biomarker of stress, during childhood and possibly at mature age. Twenty-four female guinea pigs were fed an iron-sufficient (IS) diet (114 mg/kg) or ID diet (11.7 mg/kg) during the gestation and lactation. Pups in both groups were weaned at postnatal day (PNd) 9 and given an IS diet. Hematocrit and serum cortisol levels were measured in dams at every trimester of gestation and in pups at PNd24 and 84. We found no impact of MID on dam's cortisol values. However, our findings indicate that MID increased cortisol secretion in the offspring during childhood, cortisol values being significantly elevated in ID than IS pups at PNd24 (P < .05). During adulthood (PNd84), both groups showed comparable cortisol levels. The elevated cortisol secretion observed in the offspring born from ID mothers during childhood may indicate increased stress reactivity which may have contributed to the higher level of activity when tested in a novel open environment. These findings suggest that MID can potentially act as internal stressor affecting the early development conceivably leading to increased stress levels in the children.