The Value of Next-Generation Sequencing in Diagnosis and Therapy of Critically Ill Patients with Suspected Bloodstream Infections: A Retrospective Cohort Study

Bloodstream infection (BSI), a frequent cause of severe sepsis, is a life-threatening complication in critically ill patients and still associated with a high mortality rate. Rapid pathogen identification from blood is crucial for an early diagnosis and the treatment of patients with suspected BSI. For this purpose, novel diagnostic tools on the base of genetic analysis have emerged for clinical application. The aim of this study was to assess the diagnostic value of additional next-generation sequencing (NGS) pathogen test for patients with suspected BSI in a surgical ICU and its potential impact on antimicrobial therapy. In this retrospective single-centre study, clinical data and results from blood culture (BC) and NGS pathogen diagnostics were analysed for ICU patients with suspected BSI. Consecutive changes in antimicrobial therapy and diagnostic procedures were evaluated. Results: 41 cases with simultaneous NGS and BC sampling were assessed. NGS showed a statistically non-significant higher positivity rate than BC (NGS: 58.5% (24/41 samples) vs. BC: 21.9% (9/41); p = 0.056). NGS detected eight different potentially relevant bacterial species, one fungus and six different viruses, whereas BC detected four different bacterial species and one fungus. NGS results affected antimicrobial treatment in 7.3% of cases. Conclusions: NGS-based diagnostics have the potential to offer a higher positivity rate than conventional culture-based methods in patients with suspected BSI. Regarding the high cost, their impact on anti-infective therapy is currently limited. Larger randomized prospective clinical multicentre studies are required to assess the clinical benefit of this novel diagnostic technology.

Association of reintubation and hospital costs and its modification by postoperative surveillance: A multicenter retrospective cohort study

OBJECTIVE

We estimated hospital costs associated with postoperative reintubation and tested the hypothesis that prolonged surveillance in the post-anesthesia care unit (PACU) modifies the hospital costs of reintubation.

DESIGN

Retrospective observational research study.

SETTING

Two tertiary care academic healthcare networks in the Bronx, New York and Boston, Massachusetts, USA.

PATIENTS

68,125 adult non-cardiac surgical patients undergoing general anesthesia between 2016 and 2021.

INTERVENTIONS

The exposure variable was unplanned reintubation within 7 days of surgery.

MEASUREMENTS

The primary outcome was direct hospital costs associated with patient care related activities. We used a multivariable generalized linear model based on log-transformed costs data, adjusting for pre- and intraoperative confounders. We matched our data with data from the Healthcare Cost and Utilization Project-National Inpatient Sample (HCUP-NIS). In the key secondary analysis, we examined if prolonged postoperative surveillance, defined as PACU utilization (≥4 h) modifies the association between reintubation and costs of care.

MAIN RESULTS

1759 (2.6%) of patients were re-intubated within 7 days after surgery. Reintubation was associated with higher direct hospital costs (adjusted model estimate 2.05; 95% CI: 2.00-2.10) relative to no reintubation. In the HCUP-NIS matched cohort, the adjusted absolute difference (ADadj) in costs amounted to US$ 18,837 (95% CI: 17,921-19,777). The association was modified by the duration of PACU surveillance (p-for-interaction <0.001). In patients with a shorter PACU length of stay, reintubation occurred later (median of 2 days; IQR 1, 5) versus 1 days (IQR 0, 2; p < .001), and was associated with magnified effects on hospital costs compared to patients who stayed in the PACU longer (ADadj of US$ 23,444, 95% CI: 21,217-25,799 versus ADadj of US$ 17,615, 95% CI: 16,350-18,926; p < .001).

CONCLUSION

Postoperative reintubation is associated with 2-fold higher hospital costs. Prolonged surveillance in the recovery room mitigated this effect. The cost-saving effect of longer PACU length of stay was likely driven by earlier reintubation in patients who needed this intervention.

Sex-related differences in functional capacity and its implications in risk stratification before major non-cardiac surgery: a post hoc analysis of the international METS study

Background

Poor functional capacity has been identified as an important modifiable risk factor for postoperative complications. Cardiopulmonary exercise testing (CPET) provides objective parameters of functional capacity (e.g., oxygen consumption at peak exercise, peak VO2), with significant prognostication for postoperative complications. However, sex-specific thresholds for functional capacity to predict surgical risk are yet to be established. Therefore, we performed a post hoc analysis of the international, multicentre, prospective observational METS (Measurement of Exercise Tolerance before Surgery) study to evaluate if sex-specific thresholds of peak VO2 improve risk prediction of postoperative complications.

Methods

We undertook a post hoc analysis (HREC/71824/PMCC) of the METS study, which was performed between March 2013 and March 2016. We investigated whether sex-specific differences exist for CPET-derived parameters and associated thresholds for predicting postoperative complications in this large cohort of patients that had major non-cardiac surgery (n = 1266). Logistic regression models were analyzed for the association of low peak VO2 with moderate-to-severe in-hospital postoperative complications. Optimal sex-specific peak VO2 thresholds were obtained by maximizing the Youden index of receiver operating characteristic (ROC) curves. Finally, multivariable logistic regression models tested the resulting sex-specific thresholds against the established non-sex-specific peak VO2 threshold (14 mL kg-1 min-1) adjusted for clinically relevant features such as comorbidities and surgical complexity. Models were evaluated by bootstrapping optimism-corrected area under the ROC curve and the net reclassification improvement index (NRI).

Findings

Female patients (n = 480) had a lower mean (SD) peak VO2 than males (16.7 (4.9) mL kg-1 min-1 versus 21.2 (6.5) mL kg-1 min-1, p < 0.001) and a lower postoperative complication rate (10.4% versus 15.3%; p = 0.018) than males (n = 786). The optimal peak VO2 threshold for predicting postoperative complications was 12.4 mL kg-1 min-1 for females and 22.3 mL kg-1 min-1 for males, respectively. In the multivariable regression model, low non-sex-specific peak VO2 did not independently predict postoperative complications. In contrast, low sex-specific peak VO2 was an independent predictor of postoperative complications (OR 2.29; 95% CI: 1.60, 3.30; p < 0.001). The optimism-corrected AUC-ROC of the sex-specific model was higher compared with the non-sex-specific model (0.73 versus 0.7; DeLong's test: p = 0.021). The sex-specific model classified 39% of the patients more correctly than the baseline model (NRI = 0.39; 95% CI: 0.24, 0.55). In contrast, the non-sex-specific model only classified 9% of the patients more correctly when compared against the baseline model (NRI = 0.09; 95% CI: -0.04, 0.22).

Interpretation

Our data report sex-specific differences in preoperative CPET-derived functional capacity parameters. Sex-specific peak VO2 thresholds identify patients at increased risk for postoperative complications with a higher discriminatory ability than a sex-unspecific threshold. As such, sex-specific threshold values should be considered in preoperative CPET to potentially improve risk stratification and to guide surgical decision-making, including eligibility for surgery, preoperative optimization strategies (prehabilitation) or seeking non-surgical options.

Funding

There was no funding for the present study. The original METS study was funded by Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Ministry of Health and Long-Term Care, Ontario Ministry of Research, Innovation and Science, UK National Institute of Academic Anaesthesia, UK Clinical Research Collaboration, Australian and New Zealand College of Anaesthetists, and Monash University.

Predictive value of coagulation variables and glycocalyx shedding in hospitalized COVID-19 patients - a prospective observational study

OBJECTIVES

Covid-19 disease causes an immense burden on the healthcare system. It has not yet been finally clarified which patients will suffer from a severe course and which will not. Coagulation disorders can be detected in many of these patients. The aim of the present study was therefore to identify variables of the coagulation system including standard and viscoelastometric tests as well as components of glycocalyx damage that predict admission to the intensive care unit.

METHODS

Adult patients were included within 24 h of admission. Blood samples were analyzed at hospital admission and at ICU admission if applicable. We analyzed group differences and furthermore performed receiver operator characteristics (ROC).

RESULTS

This study included 60 adult COVID-19 patients. During their hospital stay, 14 patients required ICU treatment. Comparing ICU and non-ICU patients at time of hospital admission, D-dimer (1450 µg/ml (675/2850) vs. 600 µg/ml (500/900); p = 0.0022; cut-off 1050 µg/ml, sensitivity 71%, specificity 89%) and IL-6 (47.6 pg/ml (24.9/85.4 l) vs. 16.1 pg/ml (5.5/34.4); p = 0.0003; cut-off 21.25 pg/ml, sensitivity 86%, specificity 65%) as well as c-reactive protein (92 mg/dl (66.8/131.5) vs. 43.5 mg/dl (26.8/83.3); p = 0.0029; cutoff 54.5 mg/dl, sensitivity 86%, specificity 65%) were higher in patients who required ICU admission. Thromboelastometric variables and markers of glycocalyx damage (heparan sulfate, hyaluronic acid, syndecan-1) at the time of hospital admission did not differ between groups.

CONCLUSION

General inflammatory variables continue to be the most robust predictors of a severe course of a COVID-19 infection. Viscoelastometric variables and markers of glycocalyx damage are significantly increased upon admission to the ICU without being predictors of ICU admission.

Effects of Hypobaric Hypoxia on Coagulation in Healthy Subjects Exposed to 3,500 m Altitude

Kammerer, Tobias, Anna Walzl, Thomas Müller, Philipp Groene, Giulia Roveri, Rachel Turner, Johanna Roche, Hannes Gatterer, Christoph Siebenmann, and Simon T. Schäfer. Effects of hypobaric hypoxia on coagulation in healthy subjects exposed to 3,500 m altitude. High Alt Med Biol. 24:94-103, 2023. Background: Hypoxia is discussed as a trigger for prothrombotic changes both in intensive care and high altitude medicine. This research study aimed to evaluate the effect of isolated hypobaric hypoxia (HH) on coagulation in females in a highly standardized setting. Methods: Twelve healthy female subjects were studied under HH (equivalent to 3,500 m) and normoxia (NX) during two 4-day sojourns, in a strictly controlled crossover design. Nutrition, fluid intake, hormonal status (i.e., menstrual cycle variation), and physical stress were standardized. Functional coagulation and blood lysis were measured by viscoelastometry and compared between HH and NX. In addition, plasma-based coagulation tests (PBCTs), namely prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII coagulation activity (FVIII:C), von Willebrand factor antigen (vWF:Ag), and von Willebrand factor ristocetin cofactor activity (vWF:RCo) were measured. Results: Neither for Viscoelastic Haemostatic Assays nor for PBCTs significant changes were found for HH compared with NX (all p > 0.05). Specifically, the lysis ability, as well as clotting time, clot formation, clot amplitude, and maximum clot firmness unchanged were similar between HH and NX. This also applied to all other variables. Conclusion: We demonstrate that moderate HH per se has no influence on blood coagulation in healthy females.

Hypoxia briefly increases diuresis but reduces plasma volume by fluid redistribution in women

We have recently reported that hypobaric hypoxia (HH) reduces plasma volume (PV) in men by decreasing total circulating plasma protein (TCPP). Here, we investigated whether this applies to women and whether an inflammatory response and/or endothelial glycocalyx shedding could facilitate the TCCP reduction. We further investigated whether acute HH induces a short-lived diuretic response that was overlooked in our recent study, where only 24-h urine volumes were evaluated. In a strictly controlled crossover protocol, 12 women underwent two 4-day sojourns in a hypobaric chamber: one in normoxia (NX) and one in HH equivalent to 3,500-m altitude. PV, urine output, TCPP, and markers for inflammation and glycocalyx shedding were repeatedly measured. Total body water (TBW) was determined pre- and postsojourns by deuterium dilution. PV was reduced after 12 h of HH and thereafter remained 230-330 mL lower than in NX (P < 0.0001). Urine flow was 45% higher in HH than in NX throughout the first 6 h (P = 0.01) but lower during the second half of the first day (P < 0.001). Twenty-four-hour urine volumes (P ≥ 0.37) and TBW (P ≥ 0.14) were not different between the sojourns. TCPP was lower in HH than in NX at the same time points as PV (P < 0.001), but inflammatory or glycocalyx shedding markers were not consistently increased. As in men, and despite initially increased diuresis, HH-induced PV contraction in women is driven by a loss of TCPP and ensuing fluid redistribution, rather than by fluid loss. The mechanism underlying the TCPP reduction remains unclear but does not seem to involve inflammation or glycocalyx shedding.NEW & NOTEWORTHY This study is the first to investigate the mechanisms underlying plasma volume (PV) contraction in response to hypoxia in women while strictly controlling for confounders. PV contraction in women has a similar time course and magnitude as in men and is driven by the same mechanism, namely, oncotically driven redistribution rather than loss of fluid. We further report that hypoxia facilitates an increase in diuresis, that is, however, short-lived and of little relevance for PV regulation.

Omission of tranexamic acid does not increase the amount of perioperative blood transfusions in patients undergoing one-level spinal fusion surgery: a retrospective propensity score-matched noninferiority study

INTRODUCTION

Application of tranexamic acid (TXA) in spine surgery is very frequent even without signs of hyperfibrinolysis, although its beneficial blood-saving effects are offset by harmful adverse events such as thromboembolic incidents. Thus, we investigated whether in relatively less invasive spinal procedures such as one-level posterior spinal fusion, omission of TXA affects the requirement for blood transfusions.

METHODS

We conducted a retrospective propensity score-matched noninferiority study with 212 patients who underwent one-level posterior spine fusion and who were stratified according to whether they received TXA intraoperatively at our tertiary care center. The primary endpoint was the volume of transfused packed red cells. Testing for noninferiority or equivalence was performed by two one-sided testing procedure (TOST) with a priori defined noninferiority margins ([Formula: see text]).

RESULTS

After propensity score matching a total of five patients (11.6%) treated with TXA were transfused compared with five patients (11.6%) who did not receive TXA. The majority of patients (51.2%) had a risk-increasing condition. The risk difference (no TXA-TXA) of intraoperative transfusion was - 4.7% (CI 90% - 13.62 to 4.32%), and omitting TXA was noninferior ([Formula: see text] = [Formula: see text]  10%). The mean intergroup difference in transfused volume (no TXA-TXA) was - 23.26 ml intraoperatively (CI 90% - 69.34 to 22.83 ml) and - 46.51 ml overall (CI 90% - 181.12 to 88.1 ml), respectively, suggesting equivalence of TXA omission ([Formula: see text] = [Formula: see text] 300 ml). The hemoglobin decline between both groups was also equivalent (with [Formula: see text] = [Formula: see text] 1 g/dl) both on the first postoperative day ([Formula: see text] Hb = 0.02 g/dl, CI 90% - 0.53 to 0.56 g/dl) and at discharge ([Formula: see text] Hb = - 0.29 g/dl, CI 90% - 0.89 to 0.31 g/dl).

CONCLUSION

We demonstrated that requirement of transfusion is rare among one-level fusion surgery and the omission of TXA is noninferior with regard to blood transfusion in high-risk patients undergoing this procedure. Therefore, the prophylactic use of TXA cannot be recommended here, suggesting to focus on alternative blood conservation strategies, if necessary.

Coagulation under Mild Hypothermia Assessed by Thromboelastometry

Introduction

While previous studies have shown a significant impact of extreme hypo- and hyperthermia on coagulation, effects of much more frequently occurring perioperative mild hypothermia are largely unknown. This study therefore aimed to analyze the effects of mild hypothermia using rotational thromboelastometry in vitro.

Materials and Methods

Twelve healthy volunteers were included in this study. Standard thromboelastometric tests (EXTEM, INTEM, FIBTEM) were used to evaluate coagulation in vitro at 39, 37, 35.5, 35, and 33°C. Beyond standard thromboelastometric tests, we also evaluated the effects of mild hypothermia on the TPA-test (ClotPro, Enicor GmbH, Munich, Germany), a new test which aims to detect fibrinolytic capacity by adding tissue plasminogen activator to the sample. Data are presented as the median with 25/75th percentiles.

Results

Extrinsically activated coagulation (measured by EXTEM) showed a significant increase in clot formation time (CFT; 37°C: 90 s [81/105] vs. 35°C: 109 s [99/126]; p = 0.0002), while maximum clot firmness (MCF) was not significantly reduced. Intrinsically activated coagulation (measured by INTEM) also showed a significant increase in CFT (37°C: 80 s [72/88] vs. 35°C: 94 s [86/109]; p = 0.0002) without significant effects on MCF. Mild hypothermia significantly increased both the lysis onset time (136 s [132/151; 37°C] vs. 162 s [141/228; 35°C], p = 0.0223) and lysis time (208 s [184/297; 37°C] vs. 249 s [215/358; 35°C]; p = 0.0259).

Conclusion

This demonstrates that even under mild hypothermia coagulation is significantly altered in vitro. Perioperative temperature monitoring and management are greatly important and can help to prevent mild hypothermia and its adverse effects. Further investigation and in vivo testing of coagulation under mild hypothermia is needed.

Point-of-care detection and differentiation of anticoagulant therapy - development of thromboelastometry-guided decision-making support algorithms

Background

DOAC detection is challenging in emergency situations. Here, we demonstrated recently, that modified thromboelastometric tests can reliably detect and differentiate dabigatran and rivaroxaban. However, whether all DOACs can be detected and differentiated to other coagulopathies is unclear. Therefore, we now tested the hypothesis that a decision tree-based thromboelastometry algorithm enables detection and differentiation of all direct Xa-inhibitors (DXaIs), the direct thrombin inhibitor (DTI) dabigatran, as well as vitamin K antagonists (VKA) and dilutional coagulopathy (DIL) with high accuracy.

Methods

Following ethics committee approval (No 17–525-4), and registration by the German clinical trials database we conducted a prospective observational trial including 50 anticoagulated patients (n = 10 of either DOAC/VKA) and 20 healthy volunteers. Blood was drawn independent of last intake of coagulation inhibitor. Healthy volunteers served as controls and their blood was diluted to simulate a 50% dilution in vitro. Standard (extrinsic coagulation assay, fibrinogen assay, etc.) and modified thromboelastometric tests (ecarin assay and extrinsic coagulation assay with low tissue factor) were performed. Statistical analyzes included a decision tree analyzes, with depiction of accuracy, sensitivity and specificity, as well as receiver-operating-characteristics (ROC) curve analysis including optimal cut-off values (Youden-Index).

Results

First, standard thromboelastometric tests allow a good differentiation between DOACs and VKA, DIL and controls, however they fail to differentiate DXaIs, DTIs and VKAs reliably resulting in an overall accuracy of 78%. Second, adding modified thromboelastometric tests, 9/10 DTI and 28/30 DXaI patients were detected, resulting in an overall accuracy of 94%. Complex decision trees even increased overall accuracy to 98%. ROC curve analyses confirm the decision-tree-based results showing high sensitivity and specificity for detection and differentiation of DTI, DXaIs, VKA, DIL, and controls.

Conclusions

Decision tree-based machine-learning algorithms using standard and modified thromboelastometric tests allow reliable detection of DTI and DXaIs, and differentiation to VKA, DIL and controls.

Trial registration

Clinical trial number: German clinical trials database ID: DRKS00015704.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00313-7.

Effects of controlled ovarian stimulation on vascular barrier and endothelial glycocalyx: a pilot study

Purpose

Controlled ovarian stimulation significantly amplifies the number of maturing and ovulated follicles as well as ovarian steroid production. The ovarian hyperstimulation syndrome (OHSS) increases capillary permeability and fluid extravasation. Vascular integrity intensely is regulated by an endothelial glycocalyx (EGX) and we have shown that ovulatory cycles are associated with shedding of EGX components. This study investigates if controlled ovarian stimulation impacts on the integrity of the endothelial glycocalyx as this might explain key pathomechanisms of the OHSS.

Methods

Serum levels of endothelial glycocalyx components of infertility patients (n=18) undergoing controlled ovarian stimulation were compared to a control group of healthy women with regular ovulatory cycles (n=17).

Results

Patients during luteal phases of controlled ovarian stimulation cycles as compared to normal ovulatory cycles showed significantly increased Syndecan-1 serum concentrations (12.6 ng/ml 6.11^25th–19.13^75th to 13.9 ng/ml 9.6^25th–28.9^75th; p=0.026), indicating shedding and degradation of the EGX.

Conclusion

A shedding of EGX components during ovarian stimulation has not yet been described. Our study suggests that ovarian stimulation may affect the integrity of the endothelial surface layer and increasing vascular permeability. This could explain key features of the OHSS and provide new ways of prevention of this serious condition of assisted reproduction.

Cannulation of the popliteal vein as an intraoperative emergency access in prone position: A case report

Many surgeries have to be performed in the prone position. Access to central vessels is very limited in this position. This requires forward planning with regard to the placement of a central venous catheter. Emergency situations or unexpected intraoperative events in prone position are challenging, as a conventional central venous access is not possible. We describe the cannulation of the popliteal vein in such a case. We report the case of a patient with severe intracerebral hemorrhage who was transferred to our emergency department where his clinical condition rapidly deteriorated. Due to the surgical approach, a prone position was necessary and preoperative central venous cannulation was not possible. We therefore performed an alternative vascular access in prone position using a ultrasound-guided cannulation of the popliteal vein. The cannulation of the popliteal vein described here can be carried out as a quick and easy feasible alternative in emergency situations in prone position. The ultrasound-guided catheter insertion succeeded without any problems and there was no evidence of a deep vein thrombosis after the intervention.

Viscoelastometry for detecting oral anticoagulants

Background

Determination of anticoagulant therapy is of pronounced interest in emergency situations. However, routine tests do not provide sufficient insight. This study was performed to investigate the impact of anticoagulants on the results of viscoelastometric assays using the ClotPro device.

Methods

This prospective, observational study was conducted in patients receiving dabigatran, factor Xa (FXa)-inhibitors, phenprocoumon, low molecular weight heparin (LMWH) or unfractionated heparin (UFH) (local ethics committee approval number: 17–525-4). Healthy volunteers served as controls. Viscoelastometric assays were performed, including the extrinsic test (EX-test), intrinsic test (IN-test) Russel’s viper venom test (RVV-test), ecarin test (ECA-test), and the tissue plasminogen activator test (TPA-test).

Results

70 patients and 10 healthy volunteers were recruited. Clotting time in the EX-test (CT_EX-test) was significantly prolonged versus controls by dabigatran, FXa inhibitors and phenprocoumon. CT_IN-test was prolonged by dabigatran, FXa inhibitors and UFH. Dabigatran, FXa inhibitors and UFH significantly prolonged CT_RVV-test in comparison with controls (median 200, 207 and 289 vs 63 s, respectively; all p < 0.0005). Only dabigatran elicited a significant increase in CT_ECA-test compared to controls (median 307 vs 73 s; p < 0.0001). CT_ECA-test correlated strongly with dabigatran plasma concentration (measured by anti-IIa activity; r = 0.9970; p < 0.0001) and provided 100% sensitivity and 100% specificity for detecting dabigatran. Plasma concentrations (anti-XA activity) of FXa inhibitors correlated with CT_RVV-test (r = 0.7998; p < 0.0001), and CT_RVV-test provided 83% sensitivity and 64% specificity for detecting FXa inhibitors.

Conclusions

In emergency situations, ClotPro viscoelastometric assessment of whole-blood samples may help towards determining the presence and type of anticoagulant class that a patient is taking.

Trial registration

German clinical trials database ID: DRKS00015302.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00267-w.

Functional Testing for Tranexamic Acid Duration of Action Using Modified Viscoelastometry

Introduction

Tranexamic acid (TXA) is the standard medication to prevent or treat hyperfibrinolysis. However, prolonged inhibition of lysis (so-called "fibrinolytic shutdown") correlates with increased mortality. A new viscoelastometric test enables bedside quantification of the antifibrinolytic activity of TXA using tissue plasminogen activator (TPA).

Materials and Methods

Twenty-five cardiac surgery patients were included in this prospective observational study. In vivo, the viscoelastometric TPA test was used to determine lysis time (LT) and maximum lysis (ML) over 96 h after TXA bolus. Additionally, plasma concentrations of TXA and plasminogen activator inhibitor 1 (PAI-1) were measured. Moreover, dose effect curves from the blood of healthy volunteers were performed in vitro. Data are presented as median (25-75th percentile).

Results

In vivo TXA plasma concentration correlated with LT (r = 0.55; p < 0.0001) and ML (r = 0.62; p < 0.0001) at all time points. Lysis was inhibited up to 96 h (LT_TPA-test: baseline: 398 s [229-421 s] vs. at 96 h: 886 s [626-2,175 s]; p = 0.0013). After 24 h, some patients (n = 8) had normalized lysis, but others (n = 17) had strong lysis inhibition (ML <30%; p < 0.001). The high- and low-lysis groups differed regarding kidney function (cystatin C: 1.64 [1.42-2.02] vs. 1.28 [1.01-1.52] mg/L; p = 0.002) in a post hoc analysis. Of note, TXA plasma concentration after 24 h was significantly higher in patients with impaired renal function (9.70 [2.89-13.45] vs.1.41 [1.30-2.34] µg/mL; p < 0.0001). In vitro, TXA concentrations of 10 µg/mL effectively inhibited fibrinolysis in all blood samples.

Conclusions

Determination of antifibrinolytic activity using the TPA test is feasible, and individual fibrinolytic capacity, e.g., in critically ill patients, can potentially be measured. This is of interest since TXA-induced lysis inhibition varies depending on kidney function.

Real-time detection and differentiation of direct oral anticoagulants (rivaroxaban and dabigatran) using modified thromboelastometric reagents

INTRODUCTION

Timely measurement of direct oral anticoagulants (DOACs) is challenging, though clinically important. We tested the hypotheses, that thromboelastometry is able to detect dabigatran and rivaroxaban and discriminates between dabigatran and rivaroxaban as representatives of the two groups of DOACs.

METHODS AND MATERIALS

We conducted a prospective-observational study: In-vitro dose-effect-curves for rivaroxaban and dabigatran were performed (n = 10). Ex-vivo: Patients with indication of DOAC treatment (stroke; dabigatran/rivaroxaban) were included (n = 21). Blood samples were analyzed before first intake, at first estimated peak level and at 24 h after first but before following intake and 3 h after 24 h-intake. Standard and modified thromboelastometric-assays, using low tissue factor concentrations (TFTEM) or ecarin (ECATEM) were used. Receiver-operating-characteristics-curve-analysis (ROC), regression-analysis and two-way-ANOVA were performed.

RESULTS

In-vitro: TFTEM detected dabigatran and rivaroxaban (ROC_AUC: 0.99; sensitivity/specificity: 100%/98%) but could not discriminate. Dabigatran prolongs CT_ECATEM whereas rivaroxaban did not. Clotting Time (CT)-ratio TFTEM/ECATEM discriminated highly sensitive (100%) and specific (100%) between dabigatran and rivaroxaban even at very low concentrations (ROC_AUC:1.0). CT_ECATEM correlated with dabigatran spiked concentrations (r = 0.9985; p < 0.001) and CT_TFTEM (r = 0.9363; p = 0.006) with rivaroxaban. Similarly results could be demonstrated with patient data: We confirmed the performance for the differentiation of CT-ratio TFTEM/ECATEM (sensitivity 100%/specificity 100%) at any time after first intake of either DOAC.

CONCLUSION

The thromboelastometric tests TFTEM and ECATEM detect and differentiate rivaroxaban and dabigatran. Further investigations evaluate the other DOACs and the differentiation to phenprocoumon. However, results need to be confirmed in a larger study, and especially cut off values for differentiation need to be calculated from a larger sample size.

Acute Exercise in Hypobaric Hypoxia Attenuates Endothelial Shedding in Subjects Unacclimatized to High Altitudes

Travel of unacclimatized subjects to a high altitude has been growing in popularity. Changes in endothelial shedding [circulating endothelial cells (ECs)] and hematopoietic stem and progenitor cells (CPCs) during physical exercise in hypobaric hypoxia, however, are not well understood. We investigated the change in ECs and CPCs when exposed to high altitude, after acute exercise therein, and after an overnight stay in hypobaric hypoxia in 11 healthy unacclimatized subjects. Blood withdrawal was done at baseline (520 m a.s.l.; baseline), after passive ascent to 3,883 m a.s.l. (arrival), after acute physical exercise (±400 m, postexercise) and after an overnight stay at 3,883 m a.s.l. (24 h). Mature blood cells, ECs, and CPCs were assessed by a hematology analyzer and flow cytometry, respectively. The presence of matrix metalloproteinases (MMPs), their activity, and hematopoietic cytokines were assessed in serum and plasma. EC and CPC concentrations significantly decreased after exercise (p = 0.019, p = 0.007, respectively). CPCs remained low until the next morning (24 h, p = 0.002), while EC concentrations returned back to baseline. MMP-9 decreased at arrival (p = 0.021), stayed low postexercise (p = 0.033), and returned to baseline at 24 h (p = 0.035 to postexercise). MMP-activity did not change throughout the study. Circulating MMP-9 concentrations, but not MMP-activity, were associated with EC concentrations (r_rm = 0.48, p = 0.010). CPC concentrations were not linked to hematopoietic cytokines. Acute exercise at high altitude attenuated endothelial shedding, but did not enhance regenerative CPCs. Results were not linked to endothelial matrix remodeling or CPC mobilization. These results provide information to better understand the endothelium and immature immune system during an active, short-term sojourn at high altitude.

Fluid resuscitation after severe trauma injury : U-shaped associations between tetrastarch dose and survival time or frequency of acute kidney failure

BACKGROUND

Using tetrastarch for fluid resuscitation after a severe trauma injury may increase risks of death and acute kidney injury. The importance of tetrastarch dose, however, is unknown.

METHODS

A retrospective observational study was performed in two trauma centres using data on type and amount of fluids (balanced crystalloids or tetrastarch) used for pre- and acute in-hospital shock management. We evaluate independent associations between the relative and absolute volumes of tetrastarch and 90-day survival time or the frequency of severe acute kidney failure (AKF).

RESULTS

We studied 271 patients who had sustained a severe blunt trauma injury (average predicted mortality according to the Revised Injury Severity Classification Score (RISC) 15.1 ± 1.4% [mean, standard deviation]), and who had required more than 2 days of intensive care therapy. In all, 75.3% of patients had received tetrastarch with a crystalloid/colloid ratio of 2.93 ± 2.60. The 90-day mortality was 11.1%, and 7.8% of the patients developed severe AKF. After adjusting for confounders, we found a U-shaped, nonlinear association between absolute or relative volumes of tetrastarch and survival time (p = 0.003 and 0.025, respectively). Optimal relative volumes of tetrastarch approximately ranged from 20 to 30% of total fluids. Giving less than about 1000 ml, or more than about 2000 ml tetrastarch was significantly associated with an increased risk of developing severe AKF (p = 0.023).

CONCLUSIONS

There was a complex U‑shaped association between the tetrastarch dose and morbidity/mortality of patients after a severe trauma injury. The optimal crystalloid/tetrastarch ratio for acute shock management appears to range from about 2.5 to 4.0.

Comparison of Two Different Fibrinogen Concentrates in an in vitro Model of Dilutional Coagulopathy

Introduction

Fibrinogen concentrates are widely used to restore clot stability in situations of bleeding. Fibrinogen preparations are produced using different production methods, resulting in different compounds. Thus, different preparations might have a distinct impact on blood coagulation. We tested the effect of fibrinogen concentrates Haemocomplettan® (CSL Behring, Marburg, Germany) and fibryga® (Octapharma GmbH, Langenfeld, Germany) on the impairments induced by 60% dilutional coagulopathy in vitro.

Materials and Methods

The influence of the fibrinogen concentrates fibryga® and Haemocomplettan® on colloid (gelatine, hydroxyethyl starch [HES], albumin)-induced or crystalloid (Ringer's acetate)-induced dilutional coagulopathy was analysed using rotational thromboelastometry (ROTEM®) and standard laboratory tests. The following experimental conditions were analysed in vitro: whole blood, 60% dilution (40% blood and 60% diluent) ± 50 or 100 mg/kg^-1 fibryga® or Haemocomplettan®, respectively.

Results

Dilution with either diluent resulted in prolonged clotting time (CT) in an extrinsic activated test (CT_EXTEM) and decreased maximum clot firmness (MCF_FIBTEM) as expressed, e.g., by gelatine: (59.5 s [62/54.8] vs. 95 s [102.8/86.8]; p < 0.001 and 14 mm [16/10.5] vs. 3 mm [4-3]; p < 0.001). Substitution after 60% dilution with HES resulted in no difference between the preparations, except for shorter thrombin time with fibryga® (14 s [15/14] vs. 18 s [18.8/17]; p = 0.0093; low dose). CT_EXTEM was higher with Haemocomplettan® in a gelatine-induced dilution (51 s [54.5/47.5] vs. 63 s [71/60.3]; p = 0.0202; low dose) whereas thrombin time was lower with fibryga® (19.5 s [20.8/19] vs. 27 s [29/25.3]; p = 0.0017). In dilution with albumin, differences in CT_EXTEM (69 s [76.5/66] vs. 56 s [57/53.3]; p = 0.0114; low dose) and thrombin time (18 s [18/17] vs. 24.5 s [25.8/24]; p = 0.0202; low dose) were seen. In dilution with crystalloid solution, again differences in CT_EXTEM (53.5 s [57.8/53] vs. 45 s [47/43]; p = 0.035; low dose) and thrombin time (17 s [17/16] vs. 23.5 s [24/23]; p = 0.0014; low dose) were seen. Fibrinogen levels were more increased by high-dose substitution of both preparations.

Conclusion

Based on this data it can be stated that both fibryga® and Haemocomplettan® had the same performance in our in vitro model except for CT_EXTEM and thrombin time.

Hydroxyethyl Starch 130/0.4 and Its Impact on Perioperative Outcome: A Propensity Score Matched Controlled Observation Study

BACKGROUND

Adverse effects of hydroxyethyl starches (HESs) have been verified in patients suffering from sepsis or kidney disease, but not in surgical patients at large. The investigation aimed to determine whether the use of HES 130/0.4 was associated with the incidence of acute postinterventional adverse events compared to Ringer's acetate alone in a perioperative setting.

METHODS

This propensity score matched, controlled observational study was performed in a single-centre university hospital. The perioperative data of 9085 patients were analyzed. Group matching was based on 13 categories including demographic data, type of procedure, and 5 preexisting comorbidities. Duration of procedure and intraoperative transfusion requirements were integrated in the matching process to reduce selection and indication bias. The primary outcome was incidence of postoperative kidney failure. Secondary outcomes were in-hospital mortality, fluid requirements, blood loss, hemodynamic stability, and the need for postoperative intensive care unit (ICU) treatment.

RESULTS

The administration of HES 130/0.4 was not associated with an increased frequency of postoperative kidney failure. In-hospital mortality (Ringer's acetate: 2.58%; HES 130/0.4: 2.68%) and the need for ICU care (Ringer's acetate: 30.5%; HES 130/0.4: 34.3%) did not differ significantly between groups. Significant intergroup differences were observed for mean blood loss (Ringer's acetate: 406 ± 821 mL; HES 130/0.4: 867 ± 1275 mL; P < .001) and median length of hospital stay (Ringer's acetate: 10.5 (5/17) days; HES 130/0.4: 12.0 (8/19) days; P < .001).

CONCLUSIONS

An association between intraoperative HES therapy and postoperative kidney failure was not observed in a mixed cohort of elective surgical patients. In addition, HES 130/0.4 was not associated with an increased morbidity or the need for ICU therapy in this propensity score matched study.

Changes of hemodynamic and cerebral oxygenation after exercise in normobaric and hypobaric hypoxia: associations with acute mountain sickness

Objective

Normobaric (NH) and hypobaric hypoxia (HH) are associated with acute mountain sickness (AMS) and cognitive dysfunction. Only few variables, like heart-rate-variability, are correlated with AMS. However, prediction of AMS remains difficult. We therefore designed an expedition-study with healthy volunteers in NH/HH to investigate additional non-invasive hemodynamic variables associated with AMS.

Methods

Eleven healthy subjects were examined in NH (FiO₂ 13.1%; equivalent of 3.883 m a.s.l; duration 4 h) and HH (3.883 m a.s.l.; duration 24 h) before and after an exercise of 120 min. Changes in parameters of electrical cardiometry (cardiac index (CI), left-ventricular ejection time (LVET), stroke volume (SV), index of contractility (ICON)), near-infrared spectroscopy (cerebral oxygenation, rScO₂), Lake-Louise-Score (LLS) and cognitive function tests were assessed. One-Way-ANOVA, Wilcoxon matched-pairs test, Spearman's-correlation-analysis and Student's t-test were performed.

Results

HH increased heart rate (HR), mean arterial pressure (MAP) and CI and decreased LVET, SV and ICON, whereas NH increased HR and decreased LVET. In both NH and HH cerebral oxygenation decreased and LLS increased significantly. After 24 h in HH, 6 of 11 subjects (54.6%) developed AMS. LLS remained increased until 24 h in HH, whereas cognitive function remained unaltered. In HH, HR and LLS were inversely correlated (r = - 0.692; p < 0.05). More importantly, the rScO2-decrease after exercise in NH significantly correlated with LLS after 24 h in HH (r = - 0.971; p < 0.01) and rScO2 correlated significantly with HR (r = 0.802; p < 0.01), CI (r = 0.682; p < 0.05) and SV (r = 0.709; p < 0.05) after exercise in HH.

Conclusions

Both acute NH and HH altered hemodynamic and cerebral oxygenation and induced AMS. Subjects, who adapted their CI had higher rScO2 and lower LLS. Furthermore, rScO2 after exercise under normobaric conditions was associated with AMS at high altitudes.

The impact of phosphate-balanced crystalloid infusion on acid-base homeostasis (PALANCE study): study protocol for a randomized controlled trial

Background

This study aims to investigate the effects of a modified, balanced crystalloid including phosphate in a perioperative setting in order to maintain a stable electrolyte and acid-base homeostasis in the patient.

Methods/design

This is a single-centre, open-label, randomized controlled trial involving two parallel groups of female patients comparing a perioperative infusion regime with sodium glycerophosphate and Jonosteril® (treatment group) or Jonosteril® (comparator) alone. The primary endpoint is to maintain a stable concentration of weak acids [A^-] according to the Stewart approach of acid-base balance. Secondary endpoints are measurement of serum phosphate levels, other acid-base parameters such as the strong ion difference (SID), the onset and severity of postoperative nausea and vomiting (PONV), electrolyte levels and their excretion in the urine, monitoring of renal function and glycocalyx components, haemodynamics, amounts of catecholamines and other vasopressors used and the safety of the infusion regime.

Discussion

Perioperative fluid replacement with the use of currently available crystalloid preparations still fail to maintain a stable acid-base balance and experts agree that common balanced solutions are still not ideal. This study aims to investigate the effectivity and safety of a new crystalloid solution by adding sodium glycerophosphate to a standardized crystalloid preparation in order to maintain a balanced perioperative acid-base homeostasis.

Trial registration

EudraCT number 201002422520. Registered on 30 November 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2051-z) contains supplementary material, which is available to authorized users.

[State of the art in fluid and volume therapy : A user-friendly staged concept]

Adequate fluid therapy is highly important for the perioperative outcome of our patients. Both, hypovolemia and hypervolemia can lead to an increase in perioperative complications and can impair the outcome. Therefore, perioperative infusion therapy should be target-oriented. The main target is to maintain the patient's preoperative normovolemia by using a sophisticated, rational infusion strategy.Perioperative fluid losses should be discriminated from volume losses (surgical blood loss or interstitial volume losses containing protein). Fluid losses as urine or perspiratio insensibilis (0.5-1.0 ml/kg/h) should be replaced by balanced crystalloids in a ratio of 1:1. Volume therapy step 1: Blood loss up to a maximum value of 20% of the patient's blood volume should be replaced by balanced crystalloids in a ratio of 4(-5):1. Volume therapy step 2: Higher blood losses should be treated by using iso-oncotic, preferential balanced colloids in a ratio of 1:1. For this purpose hydroxyethyl starch can also be used perioperatively if there is no respective contraindication, such as sepsis, burn injuries, critically ill patients, renal impairment or renal replacement therapy, and severe coagulopathy. Volume therapy step 3: If there is an indication for red cell concentrates or coagulation factors, a differentiated application of blood and blood products should be performed.

[Anesthesia in thoracic surgery]

Thoracic surgery represents a special challenge for anesthesia and requires a high level of human and material resources. Accurate knowledge of the pathophysiology is essential for selection of the anesthetic procedure, the separation of the lungs, monitoring and treatment of hemodynamics as well as for postoperative follow-up care. The increasing number of thoracic interventions and patients who are often suffering from complex diseases require close interdisciplinary cooperation between surgeons, anesthesiologists and intensive care specialists. In addition to the anesthetic techniques particular attention must be paid to the prevention of perioperative complications that can have a relevant effect on patient outcome. In particular hypoxemia during one-lung ventilation influences postoperative morbidity and mortality. Protective pulmonary ventilation strategies play an important role in prevention of postoperative acute lung injury.

Comparison of 6% hydroxyethyl starch and 5% albumin for volume replacement therapy in patients undergoing cystectomy (CHART): study protocol for a randomized controlled trial

Background

The use of artificial colloids is currently controversial, especially in Central Europe Several studies demonstrated a worse outcome in intensive care unit patients with the use of hydroxyethyl starch. This recently even led to a drug warning about use of hydroxyethyl starch products in patients admitted to the intensive care unit. The data on hydroxyethyl starch in non–critically ill patients are insufficient to support perioperative use.

Methods/Design

We are conducting a single-center, open-label, randomized, comparative trial with two parallel patient groups to compare human albumin 5 % (test drug) with hydroxyethyl starch 6 % 130/0.4 (comparator). The primary endpoint is cystatin C ratio, calculated as the ratio of the cystatin value at day 90 after surgery relative to the preoperative value. Secondary objectives are inter alia the evaluation of the influence of human albumin and hydroxyethyl starch on further laboratory chemical and clinical parameters, glycocalyx shedding, intensive care unit and hospital stay and acute kidney injury as defined by RIFLE criteria (risk of renal dysfunction, injury to the kidney, failure of kidney function, loss of kidney function, and end-stage kidney disease) criteria.

Discussion

There is a general lack of evidence on the relative safety and effects of hydroxyethyl starch compared with human albumin for volume replacement in a perioperative setting. Previously conducted studies of surgical patients in which researchers have compared different hydroxyethyl starch products included too few patients to properly evaluate clinical important outcomes such as renal function. In the present study in a high-risk patient population undergoing a major surgical intervention, we will determine if perioperative fluid replacement with human albumin 5 % will have a long-term advantage over a third-generation hydroxyethyl starch 130/0.4 on the progression of renal dysfunction until 90 days after surgery.

Trial registration

EudraCT number 2010-018343-34. Registered on 11 January 2010.

Use of drug-eluting balloon coronary intervention prior to living donor kidney transplantation

Background

Kidney transplantation is the gold standard of therapy in patients with terminal renal insufficiency. Living donor transplantation is a well-established option in this field. Enlarging the donor’s pool implicates the acceptance of an increased rate of comorbidities. Among them, coronary artery disease is a growing problem. An increasing number of patients, undergoing living donation, receive antiplatelet therapies due to coronary disease.

Case presentation

Here we report about the perioperative treatment with a drug-eluting balloon in a patient with major cardiac risk factors who underwent kidney transplantation.

Conclusion

At the current time no recommendation can be given for the routine use of drug-eluting balloons.

Influence of gender on postoperative outcome after intra-aortic balloon counter-pulsation and cardiac surgery

INTRODUCTION

Female gender is an established risk factor for worse outcomes after cardiac surgery, and women are more likely to experience postoperative complications. Our aim was to analyze the influence of gender on outcome and postoperative complications after the use of intra-aortic balloon counter-pulsation (IABP) in cardiac surgery patients.

METHODS

Fifty-seven consecutive female patients (mean age: 73 ± 9 years) requiring an IABP at our department from January 2007 to January 2010 were retrospectively analyzed and compared with 182 male patients receiving IABP support within the same period. The collected data included patient demographics, preoperative state, operative details, postoperative pharmacological treatment, IABP-associated complications, and inhospital mortality. Preoperative mortality risk was calculated by logistic EuroSCORE.

RESULTS

There were no differences regarding the type of operation, preoperative renal or hepatic failure, though the prevalence of peripheral artery occlusive disease was higher in men. Furthermore, female patients receiving an IABP were significantly older (73 ± 9 vs. 67 ± 10 years), had a higher ejection fraction (EF) (45% ± 24% vs. 36% ± 14%), and had a higher EuroSCORE (25% ± 20% vs. 19% ± 17%; p < 0.05). Postoperative catecholamine support was significantly higher in the female patients. Women had a prolonged length of stay (LOS) at the ICU (10.64 ± 9.7 vs. 7.6 ± 7.6 days), higher incidence of renal replacement therapy, and a higher mortality (19 [19.4%] vs. 35 [33.9%]; p < 0.05) after the use of IABP.

CONCLUSION

Women have a worse outcome after the use of IABP, including LOS at the ICU, postoperative renal failure, and inhospital mortality, despite higher EF, when compared with men.

Influence of an acetate- and a lactate-based balanced infusion solution on acid base physiology and hemodynamics: an observational pilot study

Background

The current pilot study compares the impact of an intravenous infusion of Ringer’s lactate to an acetate-based solution with regard to acid–base balance. The study design included the variables of the Stewart approach and focused on the effective strong ion difference. Because adverse hemodynamic effects have been reported when using acetate buffered solutions in hemodialysis, hemodynamics were also evaluated.

Methods

Twenty-four women who had undergone abdominal gynecologic surgery and who had received either Ringer’s lactate (Strong Ion Difference 28 mmol/L; n = 12) or an acetate-based solution (Strong Ion Difference 36.8 mmol/L; n = 12) according to an established clinical protocol and its precursor were included in the investigation. After induction of general anesthesia, a set of acid–base variables, hemodynamic values and serum electrolytes was measured three times during the next 120 minutes.

Results

Patients received a mean dose of 4,054 ± 450 ml of either one or the other of the solutions. In terms of mean arterial blood pressure and norepinephrine requirements there were no differences to observe between the study groups. pH and serum HCO₃^- concentration decreased slightly but significantly only with Ringer’s lactate. In addition, the acetate-based solution kept the plasma effective strong ion difference more stable than Ringer’s lactate.

Conclusions

Both of the solutions provided hemodynamic stability. Concerning consistency of acid base parameters none of the solutions seemed to be inferior, either. Whether the slight advantages observed for the acetate-buffered solution in terms of stability of pH and plasma HCO₃^- are clinically relevant, needs to be investigated in a larger randomized controlled trial.

[Extracorporeal membrane oxygenation (ECMO) as cardiac assist device in pediatrics]

Extracorporeal membrane oxygenation (ECMO) is a common treatment for severe respiratory failure. However, ECMO can also be used as cardiac support. ECMO is the most common mechanical circulatory assist device in pediatrics, followed by pulsatile ventricular assist devices. Advantages are the simultaneous support of respiratory and hemodynamic functions and the fast bedside availability. The major disadvantage is the limited duration of therapy. The transthoracic connection of ECMO after cardiac failure in cardiothoracic surgery in childhood allows a controlled weaning on the intensive care unit. Weaning from ECMO is successful in about 45 to 80 % in cases of circulatory support; survival rates depend on patient selection, treatment protocol and indication. Bleeding problems, thromboembolic complications, hemolysis, infections, renal and neurologic complications are major problems.

A double-blind multicentre trial comparing the efficacy and side-effects of mianserin and chlorimipramine in depressed in- and outpatients

Mianserin (60 mg daily) was compared with chlorimipramine (150 mg daily) in the treatment of 145 depressed in- and outpatients in four centres. The trial was double-blind and fully randomized. Both drugs were effective antidepressants. No significant differences in efficacy could be demonstrated by means of the Hamilton rating scale for depression, the Beck self-rating scale or the clinical global impression, for both in- and outpatients. Hypotension, dry mouth and tremor increased significantly more in inpatients with chlorimipramine than with mianserin. At the end of treatment weight gain was increased significantly more in outpatients after treatment with mianserin. No differences could be demonstrated between the drugs for other side-effects.