Team planning discussion and clinical performance: a prospective, randomised, controlled simulation trial.

Planning held before emergency management of a critical situation might be an invaluable asset for optimising team preparation. The purpose of this study was to investigate whether a brief planning discussion improved team performance in a simulated critical care situation. Forty-four pairs of trainees in anaesthesia and intensive care were randomly allocated to either an intervention or control group before participating in a standardised simulated scenario. Twelve different scenarios were utilised. Groups were stratified by postgraduate year and simulated scenario, and a facilitator was embedded in the scenario. In the intervention group, the pairs had an oral briefing followed by a 4-min planning discussion before starting the simulation. The primary end-point was clinical performance, as rated by two independent blinded assessors on a score of 0-100 using video records and pre-established scenario-specific checklists. Crisis resource management and stress response (cognitive appraisal ratio) were also assessed. Two pairs were excluded for technical reasons. Clinical performance scores were higher in the intervention group; mean (SD) 51 (9) points vs. 46 (9) in the control group, p = 0.039. The planning discussion was also associated with higher crisis resource management scores and lower cognitive appraisal ratios, reflecting a positive response. A 4-min planning discussion before a simulated critical care situation improved clinical team performance and cognitive appraisal ratios. Team planning should be integrated into medical education and clinical practice.

Use of a hand-held digital cognitive aid in simulated crises: the MAX randomized controlled trial.

BACKGROUND: Cognitive aids improve the technical performance of individuals and teams dealing with high-stakes crises. Hand-held electronic cognitive aids have rarely been investigated. A randomized controlled trial was conducted to investigate the effects of a smartphone application, named MAX (for Medical Assistance eXpert), on the technical and non-technical performance of anaesthesia residents dealing with simulated crises. METHODS: This single-centre randomized, controlled, unblinded trial was conducted in the simulation centre at Lyon, France. Participants were anaesthesia residents with >1 yr of clinical experience. Each participant had to deal with two different simulated crises with and without the help of a digital cognitive aid. The primary outcome was technical performance, evaluated as adherence to guidelines. Two independent observers remotely assessed performance on video recordings. RESULTS: Fifty-two residents were included between July 2015 and February 2016. Six participants were excluded for technical issues; 46 participants were confronted with a total of 92 high-fidelity simulation scenarios (46 with MAX and 46 without). Mean (sd) age was 27 (1.8) yr and clinical experience 3.2 (1.0) yr. Inter-rater agreement was 0.89 (95% confidence interval 0.85-0.92). Mean technical scores were higher when residents used MAX [82 (11.9) vs 59 (10.8)%; P<0.001]. CONCLUSION: The use of a hand-held cognitive aid was associated with better technical performance of residents dealing with simulated crises. These findings could help digital cognitive aids to find their way into daily medical practice and improve the quality of health care when dealing with high-stakes crises. CLINICAL TRIAL REGISTRATION: NCT02678819.

Estimated economic impact of pre-filled ephedrine syringes in the operating room.

BACKGROUND: Syringes of ephedrine are usually prepared ahead of time in order to reduce the time to injection. Commercial pre-filled syringes of ephedrine have been introduced to minimize the amount of waste. Our primary objective was to determine the economic impact of commercial syringes. We hypothesized that costs could be reduced compared to standard syringes. METHODS: Using data extracted from our medical records system, we retrospectively measured the total dose of ephedrine received per patient in 2013 to estimate the number of administered standard syringes. The proportion of administered standard syringes was calculated as the total number of administered standard syringes divided by the number of delivered ampoules in 2013. Thereafter, we calculated the annual cost difference as the difference between the cost for commercial syringes and the cost for standard syringes. Endpoints were calculated overall and for each operating room. RESULTS: At least one dose of ephedrine was given in 19,422 patients (44,943 administrations). The overall proportion of administered standard syringes was estimated to 52.8%. The threshold proportion of administered standard syringes for which commercial syringes would add no extra cost was 20.4%. In 30/32 operating rooms, the proportion of administered standard syringes was higher than 20.4%. The overall cost increase with commercial syringes was estimated to 51,567 €. Among operating rooms, incremental costs varied between -703 and 5086 €. CONCLUSION: Based on our findings, pre-filled ephedrine commercial syringes do not appear to reduce costs.

Influence of the site of measurement on the ability of plethysmographic variability index to predict fluid responsiveness.

BACKGROUND: Plethysmographic variability index (PVI) is an accurate predictor of fluid responsiveness in mechanically ventilated patients. However, the site of measurement of the plethysmographic waveform impacts its morphology and its respiratory variation. The goal of this study was to investigate the ability of PVI to predict fluid responsiveness at three sites of measurement (the forehead, ear, and finger) in mechanically ventilated patients under general anaesthesia. METHODS: We studied 28 subjects after induction of general anaesthesia. Subjects were monitored with a pulmonary artery catheter and three pulse oximeter sensors (the finger, ear, and forehead). Pulse pressure variation, central venous pressure, cardiac index (CI), and PVI measured at the forehead, ear, and finger (PVI(forehead), PVI(ear), and PVI(finger)) were recorded before and after fluid loading (FL). Subjects were responders to volume expansion if CI increased >15% after FL. RESULTS: Areas under the receiver-operating curves to predict fluid responsiveness were 0.906, 0.880, and 0.836 for PVI(forehead), PVI(ear), and PVI(finger), respectively (P<0.05). PVI(forehead), PVI(ear), and PVI(finger) had a threshold value to predict fluid responsiveness of 15%, 16%, and 12% with sensitivities of 89%, 74%, and 74% and specificities of 78%, 74%, and 67%, respectively. CONCLUSIONS: PVI can predict fluid responsiveness in anaesthetized and ventilated subjects at all three sites of measurement. However, the threshold values for predicting fluid responsiveness differ with the site of measurement. These results support the use of this plethysmographic dynamic index in the cephalic region when the finger is inaccessible or during states of low peripheral perfusion.

Pleth variability index to monitor the respiratory variations in the pulse oximeter plethysmographic waveform amplitude and predict fluid responsiveness in the operating theatre.

BACKGROUND: Respiratory variations in pulse oximetry plethysmographic waveform amplitude (DeltaPOP) can predict fluid responsiveness in mechanically ventilated patients but cannot be easily assessed at the bedside. Pleth variability index (PVI) is a new algorithm allowing for automated and continuous monitoring of DeltaPOP. We hypothesized that PVI can predict fluid responsiveness in mechanically ventilated patients under general anaesthesia. METHODS: Twenty-five patients were studied after induction of general anaesthesia. Haemodynamic data [cardiac index (CI), respiratory variations in arterial pulse pressure (DeltaPP), DeltaPOP, and PVI] were recorded before and after volume expansion (500 ml of hetastarch 6%). Fluid responsiveness was defined as an increase in CI > or =15%. RESULTS: Volume expansion induced changes in CI [2.0 (sd 0.9) to 2.5 (1.2) litre min(-1) m(-2); P<0.01], DeltaPOP [15 (7)% to 8 (3)%; P<0.01], and PVI [14 (7)% to 9 (3)%; P<0.01]. DeltaPOP and PVI were higher in responders than in non-responders [19 (9)% vs 9 (4)% and 18 (6)% vs 8 (4)%, respectively; P<0.01 for both]. A PVI >14% before volume expansion discriminated between responders and non-responders with 81% sensitivity and 100% specificity. There was a significant relationship between PVI before volume expansion and change in CI after volume expansion (r=0.67; P<0.01). CONCLUSIONS: PVI, an automatic and continuous monitor of DeltaPOP, can predict fluid responsiveness non-invasively in mechanically ventilated patients during general anaesthesia. This index has potential clinical applications.

Safety of HES 130/0.4 (Voluven(R)) in patients with preoperative renal dysfunction undergoing abdominal aortic surgery: a prospective, randomized, controlled, parallel-group multicentre trial.

BACKGROUND AND OBJECTIVE: Patients with impaired renal function are at risk of developing renal dysfunction after abdominal aortic surgery. This study investigated the safety profile of a recent medium-molecular-weight hydroxyethyl starch (HES) preparation with a low molar substitution (HES 130/0.4) in this sensitive patient group. METHODS: Sixty-five patients were randomly allocated to receive either 6% hydroxyethyl starch (Voluven); n = 32) or 3% gelatin (Plasmion); n = 33) for perioperative volume substitution. At baseline, renal function was impaired in all study patients as indicated by a measured creatinine clearance < 80 mL min(-1). The main renal safety parameter was the peak increase in serum creatinine up to day 6 after surgery. RESULTS: Both treatment groups were compared for non-inferiority (pre-defined non-inferiority range hydroxyethyl starch < gelatin + 17.68 micromol L(-1) or 0.2 mg dL(-1). Other renal safety parameters included minimum postoperative creatinine clearance, incidence of oliguria and adverse events of the renal system. Baseline characteristics, surgical procedures and the mean total infusion volume were comparable. Non-inferiority of hydroxyethyl starch vs. gelatin could be shown by means of the appropriate non-parametric one-sided 95% CI for the difference hydroxyethyl starch-gelatin [-infinity, 11 micromol L(-1)]. Oliguria was encountered in three patients of the hydroxyethyl starch and four of the gelatin treatment group. One patient receiving gelatin required dialysis secondary to surgical complications. Two patients of each treatment group died. CONCLUSION: As we found no drug-related adverse effects of hydroxyethyl starch on renal function, we conclude that the choice of the colloid had no impact on renal safety parameters and outcome in patients with decreased renal function undergoing elective abdominal aortic surgery.

[Enterovirus-related pericarditis and mediastinitis after heart surgery: a case report]. / Péricardite et médiastinite à entérovirus après chirurgie cardiaque: description d'un cas.

We report a case of enterovirus related pericarditis associated to mediastinitis in a hospitalised 53-year-old male after heart surgery. Mediastinitis caused by enterovirus has not previously been described.

Sevoflurane preconditioning at 1 MAC only provides limited protection in patients undergoing coronary artery bypass surgery: a randomized bi-centre trial.

BACKGROUND: Volatile agents can mimic ischaemic preconditioning leading to a decrease in myocardial infarct size. The present study investigated if a 15 min sevoflurane administration before cardiopulmonary bypass (CPB) has a cardioprotective effect in patients undergoing coronary surgery. METHODS: Seventy-two patients were randomized in two centres. The intervention group (S) received 1 MAC sevoflurane administrated via the ventilator for 15 min followed by a 15 min washout before CPB, the control group did not. The primary outcome was the postoperative troponin Ic peak. A biopsy of the atrium was taken during canulation for enzyme dosages. Results are expressed as mean (SD). RESULTS: Neither troponin Ic nor tissular enzyme measurement exhibited any difference between the groups: peak of troponin Ic was 4.4 (5.6) in S group vs 5.2 (6.6) ng ml(-1) in control group (ns). Intratissular ecto-5'-nucleotidase activity was 7.1 (4.3) vs 8.5 (11.9), protein kinase C activity was 27.1 (15.7) vs 29.2 (28.7), tyrosine kinase activity was 101 (54.1) vs 98.5 (63.3), and P38 MAPKinase activity was 131.1 (76.1) vs 127.1 (86.8) nmol mg protein(-1) min(-1) in S group and control group, respectively (ns). However there were fewer patients with low postoperative cardiac index in S group (11% in S vs 35% in control group, P < 0.05) when considering the per protocol population. In S group, 25% of patients required an inotropic support during the postoperative period, vs 36% of patients in control group (ns). CONCLUSIONS: This study did not show a significant preconditioning signal after 15 min of sevoflurane administration. The 15 min duration might be too short or the concentration of sevoflurane too low to induce cardioprotection detected by troponin I levels.

[From the creation to the appreciation of a pedagogic Internet site in anaesthesia and intensive care]. / De la création à l'évaluation d'un site Internet pédagogique en anesthésie-réanimation.

OBJECTIVES: The aim of this study was to conceive, create, validate and assess a pedagogic site to teach students. STUDY DESIGN: Survey with questionnaires. METHODS: First, we performed an educational need assessment in that field, conducting a review of legal regulations and international guidelines and a survey of 91 students. Afterwards, we drew up a reference document based on proven scientific data, with selected bibliography and we wrote a list of specific teaching objectives. We then created a pedagogic Web site including illustrated references, documents, a selected bibliography and useful Internet links. These pedagogic Web sites could be associated to well-conducted tutorial sites by qualified senior physicians in an academic process to improve procedural skill teaching. After internal and external validation, this educational Web site was evaluated by students. This evaluation used the questionnaire proposed by "Régie Régionale de la Santé et des Services Sociaux de Montréal" (regional authority control of health and social services of Montreal). Our pedagogic Web site obtained 76 out of 100 and can be considered satisfactory. CONCLUSION: This study demonstrated that adapted multimedia tools can improve procedural skill teaching in anaesthesia and intensive care.

[Impact of the guidelines on clinical practice of artificial nutrition in intensive care unit after cardiovascular and thoracic surgery]. / Impact d'un protocole de nutrition artificielle en réanimation après chirurgie cardiovasculaire et thoracique.

OBJECTIVE: To analyze the impact of an artificial nutrition program in post-anaesthesia intensive care unit. STUDY DESIGN: Observational study. PATIENTS AND METHODS: Patients with length of stay greater than 8 days after cardiovascular and thoracic surgery: Group 1: 34 patients (4-month period in 2000); group 2: 15 patients (2-month period in 2001); group 3: 40 patients (4-month period in 2003). Between these 3 periods, informations of physicians and written protocol in order to improve their nutritional knowledge. After analysis of variance (P<0.05). Newman-Keuls tests to compare themselves each groups. RESULTS: Anthropometric, demographic and clinical parameters were similar in the 3 groups. Energic intakes were less than 80% of basal energetic expenditures in 33%, 33 and 22% of patient, respectively (NS). Caloric and nitrogen intakes were less than recommended, respectively 19+/-6 (mean+/-SD), 21+/-7 and 21+/-8 kcal/kg/24 h and 102+/-32, 111+/-31 and 92+/-40 mg/kg/24 h (NS). However enteral nutrition was administered in 49, 40 and 100% of patients respectively (P<0.001). The glucid/lipid ratio improved from 0.47 in group 1 up to 0.68 in group 3 (P<0.0001). Vitamins, oligoelements and clinical and biological monitoring of artificial nutrition improved (P<0.001). CONCLUSION: A clinical audit demonstrated an improvement in artificial nutrition parameters but no significant change in others.

Glucose homeostasis. Comparison between hypothermic and normothermic cardiopulmonary bypass.

STUDY OBJECTIVE: Disturbance in blood glucose homeostasis during cardiac surgery may cause visceral and metabolic alterations. Hypothermic CPB induces glucose and hormonal changes. As normothermic CPB is used at some institutions, a comparison of blood glucose and plasma hormones between hypothermic and normothermic CPB was performed. DESIGN: Prospective nonrandomized study. SETTING: University cardiac center. PATIENTS: Twenty-two nondiabetic adults undergoing elective coronary bypass and/or valvular surgery. INTERVENTIONS: Group 1 (n = 12) underwent hypothermic CPB (25 degrees C) and group 2 (n = 10) normothermic CPB (37 degrees C). In both groups nonpulsatile CPB was achieved with a membrane oxygenator and dextrose-free crystalloid priming. Dextrose was not administered during surgery but was infused postoperatively (125 mg/kg/h). MEASUREMENTS AND RESULTS: Eight blood samples were drawn during the period of arrival in the operating room (control) to the third postoperative hour. During hypothermic CPB in group 1, blood glucose level increased to 154 +/- 20 mg/dl (mean +/- SD) associated with a decrease in plasma insulin and an increase in epinephrine, despite a decrease in cortisol and growth hormone. During rewarming, the blood glucose value continued to increase (to 197 +/- 35 mg/dl) associated with an increase in glucagon, growth hormone and catecholamines, despite a 374 percent increase in insulin. During CPB in group 2, insulin, glucagon, cortisol and catecholamines were significantly higher than during hypothermic CPB so that the blood glucose level was not significantly different between the two groups during CPB. Blood glucose value was higher in group 1 than in group 2 at closure of the chest (208 +/- 30 vs 175 +/- 19 mg/dl, respectively, p less than 0.02) and at the third postoperative hour (271 +/- 30 vs 221 +/- 51 mg/dl, p less than 0.01). In both groups, however, the postoperative increase in blood glucose was accompanied by a similar increase in insulin, cortisol and catecholamines but glucagon was lower after hypothermic CPB. CONCLUSIONS: Hyperglycemia occurred perioperatively in cardiac surgery with dextrose-free priming both during hypothermic and normothermic CPB but normothermic CPB resulted in a slow and steady increase in both glucose and insulin concentrations without the major perturbations that occurred with hypothermic CPB. Postoperatively, higher blood glucose was observed in the hypothermic CPB group.

Better preservation of endothelial function and decreased activation of the fetal renin-angiotensin pathway with the use of pulsatile flow during experimental fetal bypass.

OBJECTIVE: Pulsatile flow was shown to overcome the progressive rise in peripheral and placental vascular resistances observed during steady-flow bypass, this rise being counteracted by inhibition of nitric oxide synthase. This study quantifies the release of endothelial vasoactive substances during a 60-minute in utero model of fetal bypass. METHODS: Fetuses were randomly allocated into 1 of 2 groups (steady flow, n = 8, or pulsatile flow, n = 13) and subjected to bypass through central cannulation and perfusion with either a centrifugal or pulsatile (125 beats x min(-1)) blood pump. RESULTS: Lactate concentration was high, starting at fetal exteriorization and increasing during fetal preparation in the 2 groups. Once bypass was established, the rise was significant only in the steady-flow group. Plasma nitric oxide metabolites, similar before bypass, reached higher levels during pulsatile flow at the end of bypass (99+/-9 vs. 82+/-23 micromol x L(-1); P =.037). Levels of urinary nitric oxide metabolites were significantly higher in the pulsatile-flow than in the steady-flow group (764+/-143 vs. 508+/-240 micromol x L(-1); P =.005). Plasma cyclic guanosine monophosphate levels increased after 30 minutes of bypass in the pulsatile-flow group (25+/-18 vs. 12+/-8 pmol x mL(-1); P =.004), and urinary cyclic guanosine monophosphate excretion was higher in the pulsatile-flow group (517+/-450 vs. 118+/-78 pmol x mL(-1); P =.024). Plasma endothelin-1 levels increased in the 2 groups and were higher in the steady-flow group at 30 minutes (27+/-5 vs. 23+/-2 pg x mL(-1); P =.04) and 60 minutes of bypass (39+/-7 vs 32 +/- 6 pg x mL(-1); P =.04). Plasma renin concentration increased significantly during bypass only in the steady-flow group (26+/-10 vs. 57+/-42 in ng A1 x mL(-1) x h(-1); P =.04). CONCLUSIONS: Improved placental and peripheral perfusion during fetal pulsatile-flow bypass may be mediated by preservation of fetal/maternal endothelial nitric oxide biosynthetic mechanisms and/or decreased activation of the fetal renin-angiotensin pathway.

Effects of various flow types on maternal hemodynamics during fetal bypass: is there nitric oxide release during pulsatile perfusion?

OBJECTIVE: This study investigates the role of various flow conditions on maternal hemodynamics during fetal cardiopulmonary bypass. METHODS: Normothermic fetal bypass was conducted under pulsatile, or steady flow, for a 60-minute period. Fetal lamb preparations were randomly assigned to 1 of the 3 groups: steady flow (n=7), pulsatile flow (n=7), or pulsatile blocked flow bypass (n=7), where fetuses were perfused with Nomega-nitro-L-arginine after the first 30 minutes of pulsatile flow to assess the potential role of endothelial autacoids. RESULTS: Maternal oximetry and pressures remained unchanged throughout the procedure. Under fetal pulsatile flow, maternal cardiac output increased after 20 minutes of bypass and remained significantly higher than under steady flow at minute 30 (8.8+/-0.7 L x min(-1) vs 5.9+/-0.5 L x min(-1), P=.02). Maternal cardiac output in the pulsatile group also remained higher than in both steady and pulsatile blocked flow groups, reaching respectively 8.7+/-0.9 L x min(-1) vs 5.8+/-0.4 L x min(-1) (P=.02) and 5.9+/-0.3 L min(-1) (P=.01) at minute 60. Maternal systemic vascular resistances were significantly lower under pulsatile than under steady flow after 30 minutes and until the end of bypass (respectively, 9.1+/-0.6 IU vs 12.7+/-1.1 IU, P=.02 and 8.9+/-0.5 IU vs 12.9+/-1.2 IU, P=.01). Infusion of Nomega-nitro-L-arginine was followed by an increase in systemic vascular resistances from 9.3+/-0.7 IU, similar to that of the pulsatile group, to 13.5+/-1 IU at 60 minutes, similar to that of the steady flow group. CONCLUSIONS: Maternal hemodynamic changes observed under fetal pulsatile flow are counteracted after infusion of Nomega-nitro-L-arginine, suggesting nitric oxide release from the fetoplacental unit under pulsatile fetal flow conditions.

Biphasic response after brain death induction: prominent part of catecholamines release in this phenomenon.

BACKGROUND: The physiopathology of hemodynamic instability that occurs after brain death remains unknown. The aim of this study was to examine the initial response to brain death induction. METHODS: After anesthesia and monitoring, 16 pigs were randomized into a control group (C, n = 8) and a brain death group (BD, n = 8). We inflated a subdural catheter balloon to induce brain death. We analyzed hemodynamic and plasmatic biochemical data for 180 minutes after brain death induction. Energetic compounds were measured. We expressed the results in comparison with the C group. RESULTS: The C group remained stable. One minute after brain death, the Cushing reflex appeared, with a hyperdynamic response to plasma catecholamines levels increasing (norepinephrine and epinephrine, 3.1-fold, p = 0. 02, and 3.8-fold, p = 0.07, respectively). After a return to baseline, we recorded a second hyperdynamic profile 120 minutes later. At this time, a second peak of catecholamines appeared (6. 3-fold, p = 0.04, and 9.1-fold, p = 0.02, concerning norepinephrine and epinephrine). At the same time, we observed brief myocardial lactate production (+175%, p < 0.01), with a rise of troponine I (+64%, p = 0.03). The energetic index was similar in both groups: 0. 85 (+/-0.02) in the C group vs 0.87 (+/-0.02) in the BD group. CONCLUSIONS: In this model, biphasic plasmatic catecholamine release appears to primarily explain the physiopathology of the hemodynamic response to brain death induction.

Cardiac surgery with cardiopulmonary bypass in patients with type II heparin-induced thrombocytopenia.

BACKGROUND: The use of cardiopulmonary bypass (CPB) in patients with a history of type II heparin-induced thrombocytopenia (HIT) may be associated with complications related to their anticoagulation management. METHODS: Between January 1997 and December 1999, among 4,850 adults patients who underwent cardiac surgery in our institution, 10 patients presented with preoperative type II HIT. In 4 patients, anticoagulation during CPB was achieved with danaparoid sodium. In 6 other patients, heparin sodium was used after pretreatment with epoprostenol sodium. RESULTS: No significant change in platelet count occurred in any patient. No intraoperative thrombotic complication was encountered. Total postoperative chest drainage ranged from 250 to 1,100 ml in patients pretreated with epoprostenol and 1,700 to 2,470 ml in patients who received danaparoid sodium during CPB (p < 0.05, Mann-Whitney U test). CONCLUSIONS: During CPB, inhibition of platelet aggregation by prostacyclin may be a safe anticoagulation approach in patients with type II HIT.

Glucose and insulin supply before cardiopulmonary bypass in cardiac surgery: a double-blind study.

A double-blind study versus placebo was carried out to evaluate the effects of a 500-mL infusion of 30% glucose containing 300 units of ordinary insulin and 5 g of potassium chloride administered at a rate of 1.66 mL.kg-1.h-1 for 1 hour before cardiopulmonary bypass. The hemodynamic parameters measured before and after administration of the solution, after cardiopulmonary bypass, after administration of protamine, and 3 hours after leaving the operating room showed the beneficial effect of the glucose-insulin-potassium infusion on cardiac index (+23.6% after protamine infusion) and left (+16.3% 3 hours postoperatively) and right (+47.3% after cardiopulmonary bypass) ventricular workload index with a decrease in systemic vascular resistance. For patients with a cardiac index of less than 2.5 L.min-1.m-2 before administration of the glucose-insulin-potassium solution, the beneficial effect on the cardiac index was further increased 3 hours postoperatively (+33%). During the postoperative period, the requirements in inotropic drugs and disturbances of rhythm were not significantly different between the two groups, although they were twofold lower in patients receiving glucose-insulin-potassium. Laboratory tests showed that postoperative hypoglycemia was more common in the glucose-insulin-potassium group but had no detrimental effects; it no longer occurs since we began administering the glucose infusion at 15 g/h over 8 hours. The data reflect the beneficial effect associated with the action of glucose-insulin-potassium on myocardial protection during heart operations and were confirmed by the hemodynamic results. This argues in favor of the routine use of this technique, especially in patients with poor ventricular function.

Pharmacokinetics of methohexital during cardiovascular surgery with cardiopulmonary bypass.

The pharmacokinetics of methohexital after intravenous bolus administration was studied during cardiovascular surgery with cardiopulmonary bypass. The effect of body temperature (normothermia and hypothermia) during cardiopulmonary bypass on methohexital pharmacokinetics was investigated. The pharmacokinetic data obtained were compared with those from vascular surgery without cardiopulmonary bypass. A marked decrease in plasma methohexital concentrations and therefore in area under curve and a significant increase in clearance and in volume of distribution were observed in the cardiopulmonary bypass groups compared to the vascular surgery group without cardiopulmonary bypass. However, the elimination half-life and the mean residence time were similar in the 2 groups. Furthermore, the study shows that body temperature during cardiopulmonary bypass does not influence methohexital pharmacokinetics.