A dynamic time-to-event model for prediction of acute graft-versus-host disease in patients after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Acute graft-versus-host disease (aGvHD) is a major cause of death for patients following allogeneic hematopoietic stem cell transplantation (HSCT). Effective management of moderate to severe aGvHD remains challenging despite recent advances in HSCT, emphasizing the importance of prophylaxis and risk factor identification. METHODS: In this study, we analyzed data from 1479 adults who underwent HSCT between 2005 and 2017 to investigate the effects of aGvHD prophylaxis and time-dependent risk factors on the development of grades II-IV aGvHD within 100 days post-HSCT. RESULTS: Using a dynamic longitudinal time-to-event model, we observed a non-monotonic baseline hazard overtime with a low hazard during the first few days and a maximum hazard at day 17, described by Bateman function with a mean transit time of approximately 11 days. Multivariable analysis revealed significant time-dependent effects of white blood cell counts and cyclosporine A exposure as well as static effects of female donors for male recipients, patients with matched related donors, conditioning regimen consisting of fludarabine plus total body irradiation, and patient age in recipients of grafts from related donors on the risk to develop grades II-IV aGvHD. Additionally, we found that higher cumulative hazard on day 7 after allo-HSCT are associated with an increased incidence of grades II-IV aGvHD within 100 days indicating that an individual assessment of the cumulative hazard on day 7 could potentially serve as valuable predictor for later grades II-IV aGvHD development. Using the final model, stochastic simulations were performed to explore covariate effects on the cumulative incidence over time and to estimate risk ratios. CONCLUSION: Overall, the presented model showed good descriptive and predictive performance and provides valuable insights into the interplay of multiple static and time-dependent risk factors for the prediction of aGvHD.

Deep Neural Network Driven Speech Classification for Relevance Detection in Automatic Medical Documentation.

The automation of medical documentation is a highly desirable process, especially as it could avert significant temporal and monetary expenses in healthcare. With the help of complex modelling and high computational capability, Automatic Speech Recognition (ASR) and deep learning have made several promising attempts to this end. However, a factor that significantly determines the efficiency of these systems is the volume of speech that is processed in each medical examination. In the course of this study, we found that over half of the speech, recorded during follow-up examinations of patients treated with Intra-Vitreal Injections, was not relevant for medical documentation. In this paper, we evaluate the application of Convolutional and Long Short-Term Memory (LSTM) neural networks for the development of a speech classification module aimed at identifying speech relevant for medical report generation. In this regard, various topology parameters are tested and the effect of the model performance on different speaker attributes is analyzed. The results indicate that Convolutional Neural Networks (CNNs) are more successful than LSTM networks, and achieve a validation accuracy of 92.41%. Furthermore, on evaluation of the robustness of the model to gender, accent and unknown speakers, the neural network generalized satisfactorily.

XplOit: An Ontology-Based Data Integration Platform Supporting the Development of Predictive Models for Personalized Medicine.

Predictive models can support physicians to tailor interventions and treatments to their individual patients based on their predicted response and risk of disease and help in this way to put personalized medicine into practice. In allogeneic stem cell transplantation risk assessment is to be enhanced in order to respond to emerging viral infections and transplantation reactions. However, to develop predictive models it is necessary to harmonize and integrate high amounts of heterogeneous medical data that is stored in different health information systems. Driven by the demand for predictive instruments in allogeneic stem cell transplantation we present in this paper an ontology-based platform that supports data owners and model developers to share and harmonize their data for model development respecting data privacy.

Intravenous buspirone for the prevention of postoperative nausea and vomiting.

RATIONALE: Buspirone, a partial 5HT(1A) agonist and D2 and D3 antagonist, has shown promising antiemetic efficacy when given parenterally in animal models, but its efficacy for the prevention of postoperative nausea and vomiting (PONV) is unknown. OBJECTIVE: To study the efficacy and dose-responsiveness of intravenous buspirone for the prevention of PONV. METHODS: A randomised, double-blind, placebo-controlled study was performed in adults at moderate to high PONV risk undergoing surgery with a general anaesthetic. Patients were randomised to receive an intravenous dose of buspirone (0.3, 1.0, 2.0, 3.0 mg) or placebo at the end of surgery. The primary endpoint was the cumulative 24-h PONV incidence (i.e. any nausea and/or vomiting). Vomiting included retching. Nausea was defined as a score of ≥ 4 on an 11-point verbal rating scale running from zero (no nausea) to ten (the worst nausea imaginable). RESULTS: A total of 257 patients received the study drug and fulfilled the criteria for inclusion in the primary efficacy and safety analyses. With placebo, the mean 24-h PONV incidence was 49.0 % (90 % confidence interval [CI] 37.5-60.5 %). With buspirone, that incidence ranged from a mean of 40.8 % (29.3-52.4 %) in the 1 mg arm to 58.0 % (46.5-69.5 %) in the 0.3 mg arm (P > 0.05 for all comparisons). There was no difference between placebo and buspirone at any dose for any other efficacy endpoint, nor in the number or severity of adverse events or any other safety measures. CONCLUSION: We were unable to show that intravenous single-dose buspirone, at the tested dose-range, was effective at preventing PONV in surgical adult patients. The present study emphasises the difficulty in extrapolating from animal models of emesis to clinical efficacy in PONV.

Usefulness of monitoring platelet function by multiple electrode aggregometry in primary coronary artery bypass surgery.

OBJECTIVES: Antiplatelet therapy commonly is used for the prevention of cardiovascular complications but increases the risk of perioperative bleeding. Multiple-electrode aggregometry (MEA) was investigated for monitoring platelet inhibition by acetylsalicylic acid (ASA) and clopidogrel in patients undergoing elective coronary artery bypass graft (CABG) surgery with regard to clinical outcome as measured by postoperative blood loss and transfusion requirements. DESIGN: A prospective observational study. SETTING: A teaching hospital. PARTICIPANTS: One hundred fifty patients scheduled for elective CABG surgery were included: without antiplatelet therapy (group A, n = 50), single ASA exposure (group B, n = 50), and combined therapy with ASA and clopidogrel (group C, n = 50). MEASUREMENTS AND MAIN RESULTS: MEA was assessed preoperatively using either collagen (COL-MEA) or ADP (ADP-MEA). Postoperative blood loss and transfusion requirements were recorded for 24 hours after surgery. Postoperative blood loss significantly increased only from combined antiplatelet therapy (group A: 572 ± 297 mL, group B: 721 ± 356 mL, group C: 865 ± 346, p < 0.01) and correlated with ADP (r(p) = -0.35, p < 0.01) and COL-MEA (r(p) = -0.23, p > 0.01). COL-MEA and ADP-MEA discriminated between preoperative ASA and clopidogrel intake (ASA: sensitivity = 86.3%, and specificity = 89.3%; clopidogrel: sensitivity = 87.5%, and specificity = 95.1%). The postoperative transfusion risk was increased in patients diagnosed for clopidogrel treatment by ADP-MEA (odds ratio = 2.92; confidence interval: 1.44-5.92; p = 0.005). CONCLUSIONS: MEA is a suitable method for the detection of platelet inhibition by ASA and clopidogrel in patients undergoing CABG surgery. In these patients, preoperative ADP MEA seems to indicate patients at risk for postoperative transfusion requirements.

Supplemental oxygen reduces serotonin levels in plasma and platelets during colorectal surgery and reduces postoperative nausea and vomiting.

BACKGROUND AND OBJECTIVE: it has been shown that supplemental oxygen reduces the incidence of postoperative nausea and vomiting (PONV) in patients undergoing colon surgery. Serotonin is a potent trigger of PONV. Theoretically, supplemental oxygen decreases gut ischaemia during surgery and in this way minimizes the release of serotonin. We investigated the release of serotonin during and after colorectal surgery with normal and supplemental oxygen administration. METHODS: patients (n = 53) undergoing colon surgery were randomly assigned to one of two intraoperative ventilation regimens: group A (n = 30) received 80% oxygen and 20% nitrogen mixed with desflurane and group B (n = 23) received 30% oxygen and 70% nitrogen mixed with desflurane. To verify oxygenation status, we measured the arterial oxygen partial pressure (pO2) by blood gas analysis and the intramuscular tissue oxygenation using a polarographic microoxygen sensor (Licox, GMS, Mielkendorf, Germany). Serotonin levels in plasma and in platelets were measured using high-performance liquid chromatography (HPLC) before the beginning of surgery (T0), at the end of surgery (T1), and 2 h (T2), 8 h (T3) and 24 h (T4) postoperatively. PONV was assessed in the early (0-4 h) and overall (0-24 h) postoperative period by an anaesthesiologist unaware of patients' treatment regime. RESULTS: at T1, T2 and T3, serotonin levels were significantly (T1 '80% group' 80 ± 68.2 vs. '30% group' 147 ± 130.5; T2 '80% group' 78.4 ± 61 vs. '30% group' 139 ± 103; T3 '80% group' 76.2 ± 49.5 vs. '30% group' 124 ± 73.7; P < 0.05) reduced in the '80% oxygen group'. Patients in the '80% group' showed a significantly higher pO2 and subcutaneous tissue oxygenation (ptO2). The overall incidence of PONV was significantly reduced in the '80% oxygen group' ('80% group' 7% vs. '30% group' 35%). CONCLUSION: an inspired oxygen fraction of 0.8 reduces serotonin levels significantly and decreases PONV significantly in patients undergoing colon surgery.

Goal-directed intraoperative therapy based on autocalibrated arterial pressure waveform analysis reduces hospital stay in high-risk surgical patients: a randomized, controlled trial.

INTRODUCTION: Several studies have shown that goal-directed hemodynamic and fluid optimization may result in improved outcome. However, the methods used were either invasive or had other limitations. The aim of this study was to perform intraoperative goal-directed therapy with a minimally invasive, easy to use device (FloTrac/Vigileo), and to evaluate possible improvements in patient outcome determined by the duration of hospital stay and the incidence of complications compared to a standard management protocol. METHODS: In this randomized, controlled trial 60 high-risk patients scheduled for major abdominal surgery were included. Patients were allocated into either an enhanced hemodynamic monitoring group using a cardiac index based intraoperative optimization protocol (FloTrac/Vigileo device, GDT-group, n = 30) or a standard management group (Control-group, n = 30), based on standard monitoring data. RESULTS: The median duration of hospital stay was significantly reduced in the GDT-group with 15 (12 - 17.75) days versus 19 (14 - 23.5) days (P = 0.006) and fewer patients developed complications than in the Control-group [6 patients (20%) versus 15 patients (50%), P = 0.03]. The total number of complications was reduced in the GDT-group (17 versus 49 complications, P = 0.001). CONCLUSIONS: In high-risk patients undergoing major abdominal surgery, implementation of an intraoperative goal-directed hemodynamic optimization protocol using the FloTrac/Vigileo device was associated with a reduced length of hospital stay and a lower incidence of complications compared to a standard management protocol. CLINICAL TRIAL REGISTRATION INFORMATION: Unique identifier: NCT00549419.

Hepatocellular integrity after parenteral nutrition: comparison of a fish-oil-containing lipid emulsion with an olive-soybean oil-based lipid emulsion.

BACKGROUND AND OBJECTIVE: Parenteral nutrition including lipids might be associated with liver disease. The cause leading to parenteral nutrition-related liver dysfunction remains largely unknown but is likely to be multifactorial. The study was performed to assess the effects of a lipid emulsion based on soybean oil, medium-chain triglycerides, olive and fish oil (SMOFlipid20%) compared with a lipid emulsion based on olive and soybean oil on hepatic integrity. METHODS: In a prospective, randomized, double-blinded trial, 44 postoperative patients with an indication for parenteral nutrition were allocated to one of two regimens: group A (n = 22) received SMOFlipid, group B (n = 22) a lipid emulsion based on olive and soybean oil for 5 days. Aspartate aminotransferase, alanin-aminotransferase, and serum alpha-glutathion S-transferase were measured before the start of parenteral nutrition (d0), at day 2 (d2), and day 5 (d5) after the start of parenteral nutrition. The significance level was defined at a P value of less than 0.05. RESULTS: There was no significant difference at d0, but at d2 and d5, significantly lower aspartate aminotransferase (d2: group A: 27 +/- 13 vs. group B: 47 +/- 36 U l(-1); d5: A: 31 +/- 14 vs. B: 56 +/- 45 U l(-1)), alanin-aminotransferase (d2: A: 20 +/- 12 vs. B: 42 +/- 39 U l(-1); d5: A: 26 +/- 15 vs. B: 49 +/- 44 U l(-1)), and alpha-glutathion S-transferase levels (d2: A: 5 +/- 6 vs. B: 17 +/- 21 U l(-1); d5: A: 6 +/- 7 vs. B: 24 +/- 27 microg l(-1)) were found in soybean oil, medium-chain triglycerides, olive and fish oil group compared with the control group. CONCLUSION: Hepatic integrity was well retained with the administration of SMOFlipid whereas in patients receiving a lipid emulsion based on olive and soybean oil liver enzymes were elevated indicating a lower liver tolerability.

Cardiopulmonary bypass priming using a high dose of a balanced hydroxyethyl starch versus an albumin-based priming strategy.

BACKGROUND: The optimal priming solution for cardiopulmonary bypass (CPB) is unclear. In this study, we evaluated the influence of high-volume priming with a modern balanced hydroxyethyl starch (HES) preparation on coagulation, inflammation, and organ function compared with an albumin-based CPB priming regimen. METHODS: In 50 patients undergoing coronary artery bypass grafting, the CPB circuit was prospectively and randomly primed with either 1500 mL of 6% HES 130/0.42 in a balanced electrolyte solution (Na(+) 140 mmol/L, Cl(-) 118 mmol/L, K(+) 4 mmol/L, Ca(2+) 2.5 mmol/L, Mg(++) 1 mmol/L, acetate(-) 24 mmol/L, malate(-) 5 mmol/L) (n = 25) or with 500 mL of 5% human albumin plus 1000 mL 0.9% saline solution (n = 25). Inflammation (interleukins [IL]-6, -10), endothelial damage (soluble intercellular adhesion molecule-1), kidney function (kidney-specific proteins alpha-glutathione S-transferase, neutrophil gelatinase-associated lipocalin), coagulation (measured by thrombelastometry [ROTEM, Pentapharm, Munich, Germany]), and platelet function (measured by whole blood aggregometry [Multiplate analyzer, Dynabyte Medical, Munich, Germany]) were assessed after induction of anesthesia, immediately after surgery, 5 h after surgery, and on the morning of first and second postoperative days. RESULTS: Total volume given during and after CPB was 3090 +/- 540 mL of balanced HES and 3110 +/- 450 mL of albumin. Base excess after surgery was lower in the albumin-based priming group than in the balanced HES priming group (-5.9 +/- 1.2 mmol/L vs +0.2 +/- 0.2 mmol/L, P = 0.0003). Plasma levels of IL-6, IL-10, and intercellular adhesion molecule-1 were higher after CPB in the albumin-based priming group compared with the HES priming group at all time periods (P = 0.0002). Urinary concentrations of alpha-glutathione S-transferase and neutrophil gelatinase-associated lipocalin were higher after CPB through the end of the study in the albumin group compared with the balanced HES group (P = 0.00004). After surgery through the first postoperative day, thrombelastometry data (clotting time and clot formation time) revealed more impaired coagulation in the albumin-based priming group compared with the HES priming group (P = 0.004). Compared with baseline, platelet function was unchanged in the high-dose balanced HES priming group after CPB and 5 h after surgery, but it was significantly reduced in the albumin-based priming group. CONCLUSION: High-volume priming of the CPB circuit with a modern balanced HES solution resulted in reduced inflammation, less endothelial damage, and fewer alterations in renal tubular integrity compared with an albumin-based priming. Coagulation including platelet function was better preserved with high-dose balanced HES CPB priming compared with albumin-based CPB priming.

Renal integrity in sevoflurane sedation in the intensive care unit with the anesthetic-conserving device: a comparison with intravenous propofol sedation.

BACKGROUND: Increased inorganic fluoride levels after methoxyflurane exposure in the 1970s and prolonged intraoperative sevoflurane use have been suggested to be potentially nephrotoxic. In the intensive care unit we evaluated the effect on renal integrity of short-term inhaled postoperative sedation with sevoflurane using the Anesthetic Conserving Device (ACD) compared with propofol. METHODS: In this prospective, randomized, single-blinded study, after major abdominal, vascular or thoracic surgery 125 patients were allocated to receive either sevoflurane (n = 64) via the ACD (end-tidal 0.5-1 vol%) or i.v. propofol (n = 61) for postoperative sedation up to 24 h. Urinary alpha-glutathione-s-transferase as primary outcome variable, urinary N-acetyl-glucosaminidase, serum creatinine, and inorganic fluoride concentrations, urine output and fluid management were measured preoperatively, at the end of surgery, and at 24 and 48 h postoperatively. RESULTS: The sedation time in the intensive care unit was comparable between the sevoflurane (9.2 +/- 4.3 h) and the propofol (9.3 +/- 4.7 h) group. Alpha-glutathione-s-transferase levels were significantly increased at 24 and 48 h postoperatively compared with preoperative values in both groups, without significant differences between the groups. N-acetyl-glucosaminidase and serum creatinine remained unchanged in both study groups, and urine output and creatinine clearance were comparable between the groups throughout the study period. Inorganic fluoride levels increased significantly (P < 0.001) at 24 h after sevoflurane exposure (39 +/- 25 micromol/L) compared with propofol (3 +/- 6 micromol/L) and remained elevated 48 h later (33 +/- 26 vs 3 +/- 5 micromol/L). One patient in each group suffered from renal insufficiency, requiring intensive diuretic therapy, but not dialysis, during hospital stay. CONCLUSIONS: Short-term sedation with either sevoflurane using ACD or propofol did not negatively affect renal function postoperatively. Although inorganic fluoride levels were elevated after sevoflurane exposure, glomerular and tubular renal integrity were preserved throughout the hospital stay.

Motility disorders in the ICU: recent therapeutic options and clinical practice.

PURPOSE OF REVIEW: Motility disturbances often occur in critically ill patients resulting in an increased rate of morbidity and mortality. Only limited options for treatment of gastrointestinal dysfunction have been introduced. Factors contributing to motility disorders in the ICU patient, and recent therapeutic approaches are reviewed in the following. RECENT FINDINGS: Despite the growing use of early enteral nutrition in the ICU and improvements in patients' outcome, feed intolerance and motility disorders in critical illness remain unsolved. Evaluation of pathophysiological patterns such as antro-pyloric dysfunction has led to a better knowledge of gut function, whereas development of new prokinetic agents is scarce, and enthusiasm has been cut by the withdrawal of some propulsive agents from the market. SUMMARY: The complexity of gastrointestinal motor function poses a challenge to the pharmacological modulation of gut motility. There has been progress in the understanding of pathophysiologic patterns, whereas therapeutic options are still rare. Metoclopramide and erythromycin are the best evaluated and still the most promising prokinetic agents. Only a few studies in critical illness are available, and the definite value of novel propulsive agents such as motilin agonists and mu-receptor antagonists is unclear due to small patient populations. The most reasonable approach of motility disorders in critical illness seems to be an individual assessment of all associated risk factors combined with early enteral nutrition and use of prokinetic agents.

Technical performance and reflection capacity of the anaesthetic conserving device--a bench study with isoflurane and sevoflurane.

OBJECTIVE: The anaesthetic conserving device (AnaConDa), Sedana Medical, Sundbyberg, Sweden) facilitates administration of isoflurane or sevoflurane by liquid infusion. An anaesthetic reflector inside the device conserves exhaled anaesthetic and re-supplies it during inspiration. In this bench study, we examined the influence of infusion rates and ventilatory settings on the resulting anaesthetic concentrations on patient (C(pat)) and ventilator side of the reflector (C(loss)) to describe its technical performance. METHODS: A Puritan Bennett 840 ICU ventilator (Pleasanton, US), AnaConDa, and a test lung (3 l-chloroprene-bag) were assembled. Infusion rates (IR, 0.2-50 ml h(-1)), respiratory rates (RR, 5-40 breaths min(-1)), and tidal volumes (V(T), 0.3, 0.5, and 1.0 l) were varied. C(pat) was measured via a thin catheter in the middle of the 3 l-bag in steady state (online data storage and averaging over >10 min). C(loss) was calculated from IR (to yield the volume of vapour per unit of time), and expired minute volume (in which the vapour is diluted) on the assumption that, in the steady state, input by liquid infusion equals output through the reflector. RESULTS: At lower concentrations (C(pat) < 1 vol%) the ratio C(loss)/C(pat) was constant (R(C) = 0.096 +/- 0.012) for all combinations of IR, RR and V(T), both for isoflurane and sevoflurane. The device could efficiently reflect up to 10 ml vapour per breath (e.g. 2 vol% in 0.5 l). When exceeding this capacity, surplus vapour "spilled over" and R(C) markedly increased indicating decreased performance. CONCLUSIONS: The triple product minute volume times R(C) times C(pat) describes anaesthetic losses through the reflector. It can easily be calculated as long as the 10 ml reflection capacity is not exceeded and thus R(C) is constant. Increased minute ventilation necessitates increasing the IR to keep C(pat) constant. When using large V(T) and high C(pat) "spill over" occurs. This effect offers some protection against an inadvertent overdose.

The influence of a balanced volume replacement concept on inflammation, endothelial activation, and kidney integrity in elderly cardiac surgery patients.

PURPOSE: A balanced fluid replacement strategy appears to be promising for correcting hypovolemia. The benefits of a balanced fluid replacement regimen were studied in elderly cardiac surgery patients. METHODS: In a randomized clinical trial, 50 patients aged >75 years undergoing cardiac surgery received a balanced 6% HES 130/0.42 plus a balanced crystalloid solution (n = 25) or a non-balanced HES in saline plus saline solution (n = 25) to keep pulmonary capillary wedge pressure/central venous pressure between 12-14 mmHg. Acid-base status, inflammation, endothelial activation (soluble intercellular adhesion molecule-1, kidney integrity (kidney-specific proteins glutathione transferase-alpha; neutrophil gelatinase-associated lipocalin) were studied after induction of anesthesia, 5 h after surgery, 1 and 2 days thereafter. Serum creatinine (sCr) was measured approximately 60 days after discharge. RESULTS: A total of 2,750 +/- 640 mL of balanced and 2,820 +/- 550 mL of unbalanced HES were given until the second POD. Base excess (BE) was significantly reduced in the unbalanced (from +1.21 +/- 0.3 to -4.39 +/- 1.0 mmol L(-1) 5 h after surgery; P < 0.001) and remained unchanged in the balanced group (from 1.04 +/- 0.3 to -0.81 +/- 0.3 mmol L(-1) 5 h after surgery). Evolution of the BE was significantly different. Inflammatory response and endothelial activation were significantly less pronounced in the balanced than the unbalanced group. Concentrations of kidney-specific proteins after surgery indicated less alterations of kidney integrity in the balanced than in the unbalanced group. CONCLUSIONS: A total balanced volume replacement strategy including a balanced HES and a balanced crystalloid solution resulted in moderate beneficial effects on acid-base status, inflammation, endothelial activation, and kidney integrity compared to a conventional unbalanced volume replacement regimen.

Postoperative analgosedation with S(+)-ketamine decreases the incidences of postanesthetic shivering and nausea and vomiting after cardiac surgery.

BACKGROUND: Along with postoperative nausea and vomiting (PONV), postanesthetic shivering (PAS) is one of the leading causes of distress postoperatively. Previous studies report on a decrease in incidence of PAS due to ketamine administration; however, the S(+) isomer of ketamine has not been evaluated before. Additionally the administration of ketamine minimizes the use of opioids, one of the most important risk factor of PONV. The aim of the present study was to evaluate the efficacy of S(+)-ketamine in the prophylaxis of both PAS and PONV in patients undergoing cardiac surgery. MATERIAL/METHODS: After ethics committee approval and written informed consent from the patients, 54 patients scheduled for coronary artery bypass graft surgery (CABG) were studied for both postanesthetic shivering and PONV. The sedation on the ICU was maintained using continuous infusion of propofol (1-3 mg x kg(-1) x h(-1)) and if necessary boli of 3.75 mg piritramide. At arrival in the ICU patients supplementary received either S(+)-ketamine (2 mg x kg(-1) x h(-1); group A; n=27) or 0.9% saline as placebo (group B; n=27) in a double-blind fashion. The severity of PAS was assessed by using a five-point rating scale. Fifteen minutes after extubation and 24 hours postoperatively, patients were asked about occurrence of PONV. RESULTS: In group A 4 (14.8%) patients suffered from PAS compared to 12 (44.4%) in the control group (p<0.05). The severity of shivering was significantly lower in group A than in group B (p<0.05). In group A, patients showed a significant lower incidence of PONV (3.7% vs. 33.3%) and vomiting (3.7% vs. 22.2%) compared to patients of group B (p<0.05). CONCLUSIONS: S(+)-ketamine reduced both postanesthetic shivering and postoperative nausea and vomiting, when administered for postoperative analgosedation.

The influence of aprotinin and tranexamic acid on platelet function and postoperative blood loss in cardiac surgery.

BACKGROUND: Antifibrinolytic drugs including aprotinin and tranexamic acid are currently used in cardiac surgery to reduce postoperative bleeding and transfusion requirements, and may have different effects on platelets. We therefore evaluated platelet function after cardiopulmonary bypass (CPB) and cardiac surgery to determine the effect of either aprotinin or tranexamic acid. METHODS: In a prospective, randomized study, 50 patients scheduled for elective cardiac surgery with CPB were evaluated. Patients received high-dose aprotinin (n = 25) or tranexamic acid (n = 25) as antifibrinolytic drugs. Coagulation and platelet function were assessed preoperatively, after CPB, 3 and 24 h after surgery using modified thrombelastography and whole blood aggregometry. RESULTS: Impaired coagulation after CPB occurred in both groups compared with preoperative data (P < 0.01). In contrast to modified thrombelastography, thrombin receptor-mediated aggregometry after CPB was significantly decreased only in those patients receiving tranexamic acid until the end of the study period in comparison to the aprotinin group (P < 0.05). Aprotinin-treated patients showed significantly less chest tube drainage (575 mL +/- 228 vs 1033 mL +/- 647, P < 0.05) and need for postoperative transfusion requirements (P < 0.01) compared with the tranexamic acid group. CONCLUSIONS: Platelet function measured by whole blood aggregometry is better preserved by aprotinin than tranexamic acid and may be responsible for producing less bleeding within the first 24 h after CPB.

Short-term sevoflurane sedation using the Anaesthetic Conserving Device after cardiothoracic surgery.

OBJECTIVE: We evaluated the procedure of postoperative inhalational sedation with sevoflurane using the Anaesthetic Conserving Device (ACD) with regard to recovery times, feasibility and consumption of anaesthetics in comparison to propofol. DESIGN AND SETTING: Prospective, randomised, single-blinded, controlled study in a surgical intensive care unit (ICU) of a 1,000-bed academic hospital. PATIENTS AND INTERVENTIONS: A total of 70 patients after elective coronary artery bypass graft surgery either received sevoflurane via ACD (n = 35) or propofol (n = 35) for short-term postoperative sedation in the ICU. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was extubation time from termination of sedation. Recovery times, consumption of anaesthetics, endtidal sevoflurane concentrations, length of ICU and hospital stay, and side effects were documented. Mean recovery times were significantly shorter with sevoflurane than with propofol (extubation time: 22 vs. 151 min; following commands: 7 vs. 42 min). The mean (SD) sevoflurane consumption was 3.2 +/- 1.4 mL/h to obtain mean endtidal concentrations of 0.76 vol%. No serious complications occurred during sedation with either sedative drug. The length of ICU stay was comparable in both groups, but hospital length of stay was significantly shorter in the sevoflurane group. Drug costs (in Euro) for sedation per patient were similar in both groups (sevoflurane: 15.1 +/- 9.5 ; propofol: 12.5 +/- 5.8 ), while sevoflurane sedation costs that included use of the ACD were significantly higher. CONCLUSIONS: Sevoflurane administration via ACD is an effective and safe alternative to propofol to provide postoperative short-term ICU sedation. Recovery from sedation was facilitated with sevoflurane instead of propofol and resulted in shorter extubation and ventilator times. DESCRIPTOR: Neurology/sedation, Sedation and anaesthesia.

Postoperative nausea and vomiting after surgery for prognathism: not only a question of patients' comfort. A placebo-controlled comparison of dolasetron and droperidol.

INTRODUCTION: The aim of this study was to evaluate the efficacy of dolasetron and droperidol (DHB) for preventing postoperative nausea and vomiting (PONV) in patients undergoing surgery for prognathism. MATERIAL AND METHODS: In a randomised, placebo-controlled, double-blind trial, the efficacy of 12.5 mg dolasetron i.v. and 1.25 mg DHB was evaluated in preventing PONV in 83 patients undergoing surgery for prognathism. Patients were allocated randomly to one of three groups: group A (n=27) received 12.5 mg dolasetron intravenously (i.v.), group B (n=27) received 1.25 mg DHB i.v. and placebo group C (n=29) received saline 0.9%. If patients complained of retching or vomiting or if patients demanded antiemetics, 20mg metoclopramide (MCP) i.v. was given. Postoperative nausea, postoperative vomiting, or nausea and vomiting was assessed in the postoperative period at 0-4 h and overall between 0 and 24 h. RESULTS: A significant reduction in the incidence of postoperative nausea and/or vomiting was observed in the dolasetron group (33%) when compared with DHB (81%) and placebo (86%) treated patients. No other significant differences between the DHB and the placebo group were found. Dolasetron (11%) significantly reduced vomiting in comparison with the DHB (52%) and placebo group (52%). The use of postoperative MCP per patient was significantly lower in the dolasetron group when compared with both other groups. Dolasetron significantly reduced the postoperative nausea and/or vomiting-score when compared with both other groups. There was no significant difference between DHB- and placebo-treated patients with regard to nausea and/or vomiting. CONCLUSION: Intravenous dolasetron (12.5 mg) is more effective than either intravenous DHB (1.25 mg) or placebo for preventing PONV after surgery for prognathism. It also was significantly superior to either DHB or placebo concerning nausea and vomiting and the need for MCP rescue medication.

Evaluation of a new platelet function analyzer in cardiac surgery: a comparison of modified thromboelastography and whole-blood aggregometry.

OBJECTIVES: Impaired hemostasis of multiple etiologies are often present in patients undergoing cardiopulmonary bypass (CPB) surgery. Platelet dysfunction is considered to be important in the early postoperative period. Therefore, a new whole-blood platelet function analyzer was compared with thromboelastography in predicting postoperative hemostatic outcomes as measured by blood loss and blood product use. DESIGN: Prospective study. SETTING: Teaching hospital. PARTICIPANTS: The study enrolled 54 patients scheduled for coronary artery bypass surgery with CPB. INTERVENTIONS: Coagulation and platelet function were assessed preoperatively, after CPB, at 3 hours, and at 24 hours after surgery by using thromboelastography and impedance aggregometry. Patients were divided into a transfused and nontransfused group on the basis of postoperative transfusion requirements. Postoperative blood loss and requirements of blood transfusions were documented until 24 hours postoperatively. MEASUREMENTS AND MAIN RESULTS: Twenty-five patients (46%) received postoperative blood transfusions. Impaired hemostasis occurred after CPB detected by thromboelastography (p < 0.01) and impedance aggregometry (p < 0.01). In contrast to thromboelastography, preoperative adenosine diphosphate-mediated aggregometry correlated with postoperative requirements for blood transfusion (Spearman r = -0.302, p < 0.05) and was significantly lower in patients receiving allogeneic blood transfusion compared with nontransfused patients (p < 0.05). Neither aggregometry nor thromboelastography was correlated with postoperative blood loss. CONCLUSION: Impedance aggregometry as well as thromboelastography are able to detect impaired hemostasis after CPB. In contrast to thromboelastography, aggregometry using a new whole-blood aggregometer identified patients with a reduced risk for postoperative transfusion requirements.

Total intravenous anesthesia with propofol and remifentanil is associated with a nearly twofold higher incidence in postanesthetic shivering than desflurane-fentanyl anesthesia.

BACKGROUND: Postanesthetic shivering (PAS) is a frequent side effect of general anesthesia. Previous reports on the incidence of PAS of propofol for the induction or maintenance of anesthesia have been controversial, but have not been studied in detail. The aim of the present study was to evaluate the incidence and severity of PAS in total intravenous anesthesia (TIVA) with propofol and remifentanil compared with an inhalative anesthesia. MATERIAL/METHODS: After ethics committee approval and written informed consent from the patients, 53 patients scheduled for urologic, gynecologic, or surgical operations were studied for shivering postoperatively using a five-point rating scale. They received desflurane-fentanyl based anesthesia (n=27) or TIVA with propofol and remifentanil (n=26). Hemodynamics and temperature were measured after induction of anesthesia (T0), and 5 min (T1), 15 min (T2), 30 min (T3), and 60 min (T4) after reaching the postanesthetic care unit (PACU). RESULTS: In the TIVA group, 18/26 (69.2%) patients suffered from PAS compared with 10/27 (37%) in the desflurane-fentanyl group (P<0.02). The severity of shivering was significantly higher with TIVA than with desflurane (P<0.02), whereas temperature showed no significant difference between the study groups. CONCLUSIONS: Postanesthetic shivering appears significantly more frequently and intensively after TIVA with propofol and remifentanil compared with an inhalative anesthesia with fentanyl and desflurane.

Noninvasive assessment of cardiac output using thoracic electrical bioimpedance in hemodynamically stable and unstable patients after cardiac surgery: a comparison with pulmonary artery thermodilution.

OBJECTIVE: To compare noninvasive cardiac output (CO)measurement obtained with a new thoracic electrical bioimpedance (TEB) device, using a proprietary modification of the impedance equation, with invasive measurement obtained via pulmonary artery thermodilution. DESIGN: Prospective, observational study. SETTING: Surgical intensive care unit (ICU) of a university-affiliated community hospital. PATIENTS AND PARTICIPANTS: Seventy-four adult patients undergoing elective cardiac surgery with routine pulmonary artery catheter placement. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Simultaneous paired CO and cardiac index (CI) measurements by TEB and thermodilution were obtained in mechanically ventilated patients upon admission to the ICU. For analysis of CI data the patients were subdivided into a hemodynamically stable group and a hemodynamically unstable group. The groups were analyzed using linear regression and tests of bias and precision. We found a significant correlation between thermodilution and TEB (r = 0.83; n < 0.001), accompanied by a bias of -0.01 l/min/m(2) and a precision of +/-0.57 l/min/m(2) for all CI data pairs. Correlation, bias, and precision were not influenced by stratification of the data. The correlation coefficient, bias, and precision for CI were 0.86 (n< 0.001), 0.03 l/min/m(2), and +/-0.47 l/min/m(2) in hemodynamically stable patients and 0.79 (n< 0.001), 0.06 l/min/m(2), and +/-0.68 l/min/m(2) in hemodynamically unstable patients. CONCLUSIONS: Our results demonstrate a close correlation and clinically acceptable agreement and precision between CO measurements obtained with impedance cardiography using a new algorithm to calculate CO from variations in TEB, and those obtained with the clinical standard of care, pulmonary artery thermodilution, in hemodynamically stable and unstable patients after cardiac surgery.