Improving blood product management in placenta accreta patients with severe bleeding: institutional experience.

BACKGROUND: Placenta accrete spectrum (PAS) is a significant risk factor for postpartum hemorrhage and effective blood product management is critical in ensuring patient safety. In PAS patients undergoing cesarean section (CS) blood transfusion management guided by the combined clinical experience of the anesthesiologist and surgeon with point-of-care coagulation testing appears safe and effective. We describe and evaluate our experience and identify potential areas for improvement with blood product management in this patient population. METHODS: A retrospective chart review of peri-operative demographic, anesthetic, and obstetric data was conducted for all patients with PAS undergoing CS between 2012 and 2018 at our center. To facilitate a practical evaluation of blood product management, we divided patients into two groups based on the severity of bleeding. RESULTS: A total of 221 parturients with PAS underwent CS, with 133 in group 1 requiring excessive amounts of transfusion and 88 in group 2 requiring management similar to other uncomplicated CS cases. There were no deaths or instances of disseminated intravascular coagulation, and intensive care unit admission occurred in five cases (2.2%). Patients in group 1 had higher mean nadir values of intra-operative hemoglobin and platelet count. We observed a high rate of missing data for peri-operative measurement of lactate and fibrinogen, PAS grade documentation, and temperature monitoring. CONCLUSION: Given no significant morbidity or mortality, clinical judgment in experienced centers appears safe for the management of PAS patients undergoing CS. The adoption of an institutional protocol and point-of-care coagulation testing could decrease over-transfusion and associated complications.

Core Body Temperature but Not Intraabdominal Pressure Predicts Postoperative Complications Following Closed-System Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Administration.

BACKGROUND: Hyperthermic intraperitoneal chemotherapy (HIPEC) following cytoreductive surgery (CRS), performed using closed-abdomen technique (CAT), may affect intraabdominal pressure (IAP). High IAP may increase postoperative complications due to decreased venous return and hypoperfusion to vital organs. Elevated core body temperature (CBT) may cause multiorgan dysfunction. Low IAP or CBT could result in suboptimal HIPEC and potentially translate into early disease recurrence. The aim of the present study is to identify possible correlations between IAP or CBT and postoperative complications. PATIENTS AND METHODS: Continuous intraabdominal pressure measurement was performed by intraabdominal catheter. Inflow temperature was set at 44 °C, and mean perfusate temperature was 42 °C. CBT was measured continuously in the distal esophagus. We compared the rate of postoperative complications between the low IAP group (2-10 mmHg, n = 28), target IAP group (10-20 mmHg, n = 71), and high IAP group (20-34 mmHg, n = 16) as well as with CBT as a continuous variable. RESULTS: 115 patients were included in the study. There was no difference between IAP groups in terms of age, gender, primary diagnosis, operative peritoneal cancer index, CBT, or operative time. There was no correlation between IAP and postoperative complications or with prolonged hospital stay. On multivariate analysis, elevated mean CBT was a positive predictor of postoperative complications (p = 0.035). CONCLUSIONS: IAP level during closed-abdomen technique HIPEC is not associated with postoperative complications. However, elevated CBT may increase postoperative complications.

A survey of labour ward clinicians' knowledge of maternal cardiac arrest and resuscitation.

BACKGROUND: Guidelines for the management of cardiac arrest during pregnancy exist but they are based on little research. The study hypothesis was that experienced medical clinicians who specialise in obstetric care would not follow current International Liaison Committee on Resuscitation/American Heart Association recommendations in this situation. METHODS: Following waiver of informed consent by the institutional review board, an anonymous structured scenario questionnaire survey was conducted among relevant hospital clinicians. Demographic details included field of expertise and resuscitation experience. A single case vignette of maternal cardiac arrest was presented, followed by nine questions to examine knowledge of existing recommendations for maternal cardiopulmonary resuscitation. Statistical analyses were performed using SPSS version 12 software (SPSS Inc, Chicago, IL). RESULTS: The overall response rate was 67% (30/45 questionnaires). Specialist obstetricians, midwives and anaesthetists from 17 hospitals participated. Forty-three percent (n=13) claimed broad experience, 50% (n=15) claimed some experience and 6.7% (n=2) claimed no experience in adult resuscitation. Participants were divided in their opinions regarding every choice of action: positioning, need to administer cricoid pressure during mask ventilation, timing of intubation, location of external chest compression, location of paddle placement for delivery of shock during ventricular fibrillation, the timing of defibrillation versus fetal delivery, medication doses and the need to rupture the membranes at an early phase of the resuscitation. CONCLUSION: Specialist clinicians who treat pregnant women in hospital on a daily basis possess a limited knowledge of the recommendations for treating maternal cardiac arrest.

A novel point-of-care information system reduces anaesthesiologists' errors while managing case scenarios.

BACKGROUND AND OBJECTIVES: The On-Line Electronic Help (OLEH) is a point-of-care information system for anaesthesia providers prepared by the European Society of Anaesthesiologists. In this preliminary study the effect of the OLEH availability on the incidence of knowledge-based errors during the management of case scenarios and participants' subjective evaluation of the OLEH were evaluated. METHODS: After a short training session, 48 anaesthesiologists (24 junior residents, 12 senior residents and 12 board-certified) were presented randomly with six computer screen-based case scenarios with, and six without, the option of using the OLEH. Two reviewers evaluated the answers independently according to preconfigured guidelines. RESULTS: The availability of the OLEH was associated with higher scores in 11 of the 12 scenarios, and with a decrease in the incidence of critical errors in 10 scenarios. Time to task completion was increased in one scenario only when the OLEH was used. The degree of professional experience was associated with better scores in five of the scenarios and with a reduced occurrence of critical errors in three scenarios. Forty-two out of 48 participants stated that finding information in the OLEH software was easy and that the system was helpful in managing the scenarios. CONCLUSIONS: This preliminary study demonstrates the potential value of the OLEH in decreasing the number of knowledge-based errors made by anaesthesiologists. According to the encouraging results, the OLEH system is currently under evaluation using full-scale simulation scenarios in an operating room environment.

Predicting fluid responsiveness in patients undergoing cardiac surgery: functional haemodynamic parameters including the Respiratory Systolic Variation Test and static preload indicators.

BACKGROUND: Prediction of the response of the left ventricular stroke volume to fluid administration remains an unsolved clinical problem. We compared the predictive performance of various haemodynamic parameters in the perioperative period in patients undergoing coronary artery bypass surgery. These parameters included static indicators of cardiac preload and functional parameters, derived from the arterial pressure waveform analysis. These included the systolic pressure variation (SPV) and its delta down component (dDown), pulse pressure variation (PPV), stroke volume variation (SVV), and a new parameter, termed the respiratory systolic variation test (RSVT), which is a measure of the slope of the lowest systolic pressure values during a standardized manoeuvre consisting of three successive incremental pressure-controlled breaths. METHODS: Eighteen patients were included into this prospective observational study. Seventy volume loading steps (VLS), each consisting of 250 ml of colloid administration were performed before surgery and after the closure of the chest. The response to each VLS was considered as a positive (increase in stroke volume more than 15%) or non-response. Receiver operating characteristic curves were plotted for each parameter to evaluate its predictive value. RESULTS: All functional parameters predicted fluid responsiveness better than the intrathoracic blood volume and the left ventricular end-diastolic area. Parameters with the best predictive ability were the RSVT and PPV. CONCLUSIONS: Functional haemodynamic parameters are superior to static indicators of cardiac preload in predicting the response to fluid administration. The RSVT and PPV were the most accurate predictors of fluid responsiveness, although only the RSVT is independent of the settings of mechanical ventilation.

Pulse pressure and stroke volume variations during severe haemorrhage in ventilated dogs.

BACKGROUND: Similarly to systolic pressure variation (SPV), pulse pressure variation (PPV) and stroke volume variation (SVV) derived from arterial pulse contour analysis have been shown to reflect fluid responsiveness in ventilated patients. However, unlike the SPV, both PPV and SVV have not been validated during extreme hypovolaemia. The aim of the present study was to examine whether these newly introduced variables respond to gradual hypovolaemia like the SPV by increasing gradually with each step of the haemorrhage even during extreme hypovolaemia. METHODS: SPV, SVV and PPV were measured in 8 dogs following initial volume loading (10% of the estimated blood volume administered as colloid solution), 5 steps of graded haemorrhage, each consisting of 10% of the estimated blood volume, followed by retransfusion of the shed blood. RESULTS: The correlations of the SVV, SPV and PPV to the stroke volume (SV) throughout the study were -0.89, -0.91 and -0.91, respectively. Correlations of the CVP and the global end-diastolic volume (GEDV) of the heart chambers to the SV were 0.79 and 0.95, respectively. The SPV correlated significantly with both the PPV and the SVV (r=0.97 and 0.93 respectively). However, the PPV increased by more than 400% at 50% haemorrhage compared with increases of 200% and 120% for the SVV and %SPV, respectively. CONCLUSION: This study demonstrates that the present algorithm used for the calculation of the SVV and the formula used to calculate the PPV, perform well over a wide range of preload states including severe hypovolaemia. However, the PPV changes more than the SPV and SVV. This may be due to the changing relation of the SV to the pulse pressure when the filling of the aorta is greatly decreased.

Anaesthesiologists' views on the need for point-of-care information system in the operating room: a survey of the European Society of Anaesthesiologists.

BACKGROUND AND OBJECTIVE: In this preliminary study we wanted to explore the attitudes of anaesthesiologists to a point-of-care information system in the operating room. The study was conducted as a preliminary step in the process of developing such a system by the European Society of Anaesthesiologists (ESA). METHODS: A questionnaire was distributed to all 2240 attendees of the ESA's annual meeting in Gothenburg, Sweden, which took place in April 2001. RESULTS: Of the 329 responders (response rate of 14.6%), 79% were qualified specialists with more than 10 yr of experience (68%), mostly from Western Europe. Most responders admitted to regularly experiencing lack of medical knowledge relating to real-time patient care at least once a month (74%) or at least once a week (46%), and 39% admitted to having made errors during anaesthesia due to lack of medical information that can be otherwise found in a handbook. The choice ofa less optimal but more familiar approach to patient management due to lack of knowledge was reported by 37%. Eighty-eight percent of responders believe that having a point-of-care information system for the anaesthesiologists in the operating room is either important or very important. CONCLUSIONS: This preliminary survey demonstrates that lack of knowledge of anaesthesiologists may be a significant source of medical errors in the operating room, and suggests that a point-of-care information system for the anaesthesiologist may be of value.

Effect of a single dose of esmolol on the bispectral index scale (BIS) during propofol/fentanyl anaesthesia.

BACKGROUND: Esmolol, a short-acting beta 1-antagonist, can reduce anaesthetic requirements and decrease seizure activity during electroconvulsive therapy even after a single dose of 80 mg. We studied the effect of esmolol on the bispectral index scale (BIS), which is a processed EEG recently introduced to monitor depth of anaesthesia. METHODS: We gave esmolol 80 mg to 30 healthy male patients after induction of anaesthesia using propofol, with either fentanyl (group 1) or placebo (group 2). Patients were ventilated mechanically through a laryngeal mask airway and anaesthesia was maintained using propofol to keep the BIS value between 55 and 60. RESULTS: Esmolol did not affect the BIS index value in either group. In group 1, the areas (mean (SD)) under the BIS vs time curve 3 min before and 3 min after esmolol administration were 145 (9) and 146 (8) respectively (P = 0.116). In group 2 values were 147 (8) and 146 (7) respectively (P = 0.344). In contrast, in group 1 the area under the systolic arterial pressure (SAP) curve was 299 (31) before and 270 (29) after esmolol (P < 0.001), and 156 (17) and 141 (17) respectively for heart rate (P < 0.001). In group 2 values were 326 (36) and 302 (41) for SAP (P < 0.001) and 182 (25) and 155 (22) for heart rate (P < 0.001). CONCLUSIONS: The results suggest that a single dose of esmolol affects the SAP and heart rate but does not affect BIS values.

Cardiac output assessed by arterial thermodilution during exsanguination and fluid resuscitation: experimental validation against a reference technique.

BACKGROUND AND OBJECTIVE: The arterial thermodilution technique offers the ability to measure cardiac output using only central venous and arterial catheters. However, the technique has been reported to overestimate cardiac output because of a higher loss of cold indicator due to the increased distance between the sites of injection and measurement. In this study, the two techniques were compared with respect to conditions of low cardiac output in which a longer passage time may further increase loss of indicator. METHODS: Seventeen anaesthetized dogs were studied during hypovolaemic shock and fluid resuscitation. Cardiac output measurements were carried out simultaneously by arterial and pulmonary artery thermodilution techniques. RESULTS: One-hundred-and-two measurements were performed. The mean cardiac output was 2.28 +/- 1.4Lmin(-1) by the pulmonary arterial technique and 2.29 +/- 1.56Lmin(-1) by the arterial thermodilution technique. The correlation coefficient between the two measurements was 0.95, the precision -0.04 +/- 0.41 Lmin(-1) and the limits of agreement from -0.86 to 0.78Lmin(-1). The agreement was also consistent at low cardiac outputs. CONCLUSIONS: The arterial thermodilution technique may serve as a less invasive cardiac output monitor in conditions of severe bleeding and shock.

Pressure versus volume-controlled ventilation with a laryngeal mask airway in paediatric patients.

BACKGROUND: The utility of positive pressure ventilation with the laryngeal mask airway (LMA) in children was described previously, but the possibility of gastric insufflation, related to high peak airway pressure, continues to be a disadvantage. In this prospective study, inspiratory pressures, air leak and signs of gastric insufflation were compared between volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) using an LMA. METHODS: Thirty-two ASA I patients, aged 4.5 +/- 4 years, who were scheduled for elective procedures under combined general anaesthesia and caudal analgesia, were enrolled. After inhalation induction and LMA insertion, each patient was randomly assigned to receive successively PCV and VCV. Peak pressures (PCV) and tidal volumes (VCV) were changed in order to achieve adequate ventilation [endtidal CO2 5-5.4 kPa (38-42 mmHg)]. RESULTS: Peak airway pressures were significantly lower with PCV than VCV (14.1 +/- 1.6 cmH2O versus 16.7 +/- 2.3 cmH2O, P < 0.001). No patient ventilated with PCV required peak pressure higher than 20 cmH2O compared with six patients ventilated with VCV (P < 0.05). Haemodynamic parameters, expiratory tidal volume and percent of leak were similar in both ventilatory modes and no signs of gastric insufflation were detected. CONCLUSIONS: During general anaesthesia in children using an LMA, PCV offers lower peak inspiratory airway pressures while maintaining equal ventilation compared with VCV. Although no signs of gastric insufflation were detected in both groups, the lower pressures might be significant in patients with reduced chest wall or lung compliance.

Malignant hyperinflation of the nondependent lung during chest surgery.

Unilateral malignant hyperinflation of the lungs during positive pressure mechanical ventilation was described during aggressive respiratory therapy of unilateral lung disease or in situations of significant difference in compliance between the two lungs. We report a case of malignant hyperinflation of the nondependent lung during chest surgery. The differential diagnosis and treatment with differential lung ventilation are described.

Monitored anesthesia care using remifentanil and propofol for awake craniotomy.

Adequate analgesia and sedation with adequate respiratory and hemodynamic control are needed during brain surgery in awake patients. In this study, a protocol using clonidine premedication, intraoperative propofol, remifentanil, and labetalol was evaluated prospectively in 25 patients (aged 50 +/- 16). In all but one patient, no significant problems regarding cooperation, brain swelling, or loss of control were noticed, and it was not necessary to prematurely discontinue any of the procedures. One patient, who was uncooperative and hypertensive, became apneic with increasing sedation, and needed a laryngeal mask airway inserted. Patients were hemodynamically stable; elevated systolic blood pressure (>or= 150 mm Hg) was measured infrequently, and there were no events of significant hypotension, tachycardia, or bradycardia. Events of hypoxemia (SAO2

Propofol/remifentanil versus propofol alone for bone marrow aspiration in paediatric haemato-oncological patients.

BACKGROUND: This prospective randomized study was designed to evaluate the effects of adding remifentanil to the standard propofol-based technique in the setting of paediatric haematology-oncology outpatient clinic. METHODS: Eighty ASA III paediatric patients treated in the outpatient haematology-oncology clinic requiring bone marrow aspiration were randomly assigned either to the propofol (P) or the propofol/remifentanil (PR) group. The quality of anaesthesia and recovery were evaluated. RESULTS: The total amount of propofol required to prevent patient movement was lower in the PR group. The time interval to eye opening and to home readiness was significantly lower in the PR group. Adverse respiratory events (RR < 10.min-1 or SpO2 < 90%) occurred significantly more in the propofol/remifentanil group. CONCLUSIONS: The addition of remifentanil improved the conditions during the procedure and reduced the total amount of propofol, as well as the time to home readiness. However, the addition of remifentanil is associated with an increased risk of respiratory depression.

Novel, compact, intraoperative magnetic resonance imaging-guided system for conventional neurosurgical operating rooms.

OBJECTIVE: Preliminary clinical experience with a novel, compact, intraoperative magnetic resonance imaging (MRI)-guided system that can be used in an ordinary operating room is presented. DESCRIPTION OF INSTRUMENTATION: The system features an MRI scanner integrated with an optical and MRI tracking system. Scanning and navigation, which are operated by the surgeon, are controlled by an in-room computer workstation with a liquid crystal display screen. The scanner includes a 0.12-T permanent magnet with a 25-cm vertical gap, accommodating the patient's head. The field of view is 11 x 16 cm, encompassing the surgical area of interest. The magnet is mounted on a transportable gantry that can be positioned under the surgical table when not in use for scanning, thus rendering the surgical environment unmodified and allowing the use of standard instruments. The features of the integrated navigation system allow flap planning and intraoperative tracking based on updated images acquired during surgery. OPERATIVE TECHNIQUE: Twenty patients with brain tumors were surgically treated using craniotomy or trans-sphenoidal approaches. One patient underwent conscious craniotomy with cortical mapping, and two underwent electrocorticography. EXPERIENCE AND RESULTS: Planning was accurate. Resection control images were obtained for all patients during surgery, with precise localization of residual tumor tissue. There were no surgical complications related to the use of the system. CONCLUSION: This intraoperative MRI system can function in a normal operating room modified only to eliminate radiofrequency interference. The operative environment is normal, and standard instruments can be used. The scanning and navigation capabilities of the system eliminate the inaccuracies that may result from brain shift. This novel type of intraoperative MRI system represents another step toward the introduction of the modality as a standard method in neurosurgery.

Anesthesia for magnetic resonance guided neurosurgery: initial experience with a new open magnetic resonance imaging system.

The authors present their initial experience with a compact open magnetic resonance (MR) image-guided system, (PoleStar N-10, Odin Medical Technologies, Yokneam, Israel) used in a standard operating room, modified for radio frequency (RF) shielding. The low intensity of the magnetic field (0.12T), and the ability to lower the magnet from the operative field during surgery allows for an almost routine surgical procedure, in addition to the benefits of using intraoperative MR imaging. Although an MR compatible anesthesia machine and monitoring system are used, the system offers anesthesiologists access to the patient at all times during the procedure, and the ability to use conventional surgical equipment, syringe pumps, and warming devices. Propofol and remifentanil, used for maintaining anesthesia, allow early extubation and neurological evaluation at the end of surgery. Electrocorticographic monitoring can be used during surgery for epilepsy, and awake craniotomy can be performed. More experience with this new imaging system is required to assess its influence on clinical decision making and outcome.

Stroke volume variation as a predictor of fluid responsiveness in patients undergoing brain surgery.

UNLABELLED: Changes in arterial blood pressure induced by mechanical ventilation allow assessment of cardiac preload. In this study, stroke volume variation (SVV), which is the percentage change between the maximal and minimal stroke volumes (SV) divided by the average of the minimum and maximum over a floating period of 30 s, continuously displayed by the PiCCO continuous cardiac output monitor, was evaluated as a predictor of fluid responsiveness. Fifteen patients undergoing brain surgery were included. During surgery, graded volume loading was performed with each volume loading step (VLS) consisting of 100 mL of 6% hydroxyethylstarch given for 2 min. Successive responsive VLSs were performed (increase in SV > 5% after a VLS) until a change in SV of < 5 % was reached (nonresponsive). A total of 140 VLSs were performed. Responsive and nonresponsive VLSs differed in their pre-VLS values of systolic blood pressure, SV, and SVV, but not in the values of heart rate and central venous pressure. By using receiver operating characteristic analysis, the area under the curve for SVV (0.870, 95% confidence interval [CI]: 0.809 to 0.903) was statistically more than those for central venous pressure (0.493, 95% CI: 0.397 to 0.590, P = 7 x 10(-10)), heart rate (0.593, 95% CI: 0.443 to 0.635, P = 5.7 x 10(-10)), and systolic blood pressure (0.729, 95% CI: 0.645 to 0.813, P: = 4.3 x 10(-3)). An SVV value of 9.5% or more, will predict an increase in the SV of at least 5% in response to a 100-mL volume load, with a sensitivity of 79% and a specificity of 93%. IMPLICATIONS: Stroke volume variation may be used as a continuous preload variable and in combination with the continuously measured cardiac output, defining on-line the most important characteristics of cardiac function, allowing for optimal fluid management.

Continuous psoas compartment block for anesthesia and perioperative analgesia in patients with hip fractures.

BACKGROUND AND OBJECTIVES: The perioperative use of continuous psoas compartment block (CPCB) was compared with traditional pain management for patients with fracture of the femur. The anatomy of CPCB was also tested in cadavers. METHODS: Forty consecutive patients (range, 67-96 years old) were prospectively randomized either to group A (given local anesthetics using a CPCB) or group B (given perioperative analgesia with meperidine). In another part of the study, CPCB was performed in 15 fresh cadavers, and dissection of the lumbar region was performed after dye injection. RESULTS: Continuous psoas compartment block was performed successfully in all patients in group A and was used in the pre- (16-48 hours) and postoperative (72 hours) periods. Visual analog scale score in group A was lower than in group B in 5/7 preoperative and 9/9 postoperative 8 hourly assessments. Differences reached statistical significance (P < .05) in 3 and 5 of the assessments, respectively. Patient satisfaction was higher in group A in the pre- (P < .05) and postoperative periods (P<.03). The block failed to achieve surgical anesthesia in 85% (17/20) of the patients, and additional anesthesia was needed. The anatomic study failed to support the existence of a defined "psoas compartment" previously described, and supported the clinical findings. Injected dye was found in the region of the origin of the sciatic nerve (essential for the production of anesthesia for hip surgery) in only 26% (4/15) of cadavers. CONCLUSIONS: The CPCB seems to be an appropriate technique for efficient and safe perioperative pain control. However, in our dissections, the psoas compartment was not well defined in all patients, thus, using this route for anesthesia may result in only partial success.

The effect of a chemical protective ensemble on intravenous line insertion by emergency medical technicians.

Protective gear is mandatory for medical personnel treating casualties in a contaminated environment. In the present study, we assessed the ability of emergency medical technicians to insert an intravenous line in this situation. Sixty emergency medical technicians were randomized to a control group, wearing fatigues, and a study group, wearing full protective gear. The ability to insert an intravenous line in healthy volunteers was assessed 1, 2, 4, and 8 hours after randomization. We found no effect of protective gear (p = 0.543) or time in protective gear (p = 0.8869) on success rate or on time needed for successful task completion (p = 0.4005 and p = 0.9021, respectively). The overall success rate was 58.6%, 65% in the unprotected state and 56% in the protected state, and the time was 303 +/- 115 and 351 +/- 113 seconds, respectively. These findings suggest that introduction of an intravenous line is possible but time consuming even after a prolonged stay in full protective gear. Alternative methods for antidotal treatment, such as the use of automatic autoinjectors for intramuscular administration, might be suggested.

The pharmacokinetics of morphine and lidocaine in critically ill patients.

OBJECTIVE: To evaluate the pharmacokinetic parameters of morphine and lidocaine after a single intravenous dose in critically ill patients. DESIGN: Prospective, clinical study. SETTING: General intensive care unit (ICU) in a university hospital. PATIENTS: Patients admitted to the ICU with severe systemic inflammatory response syndrome of various etiologies. INTERVENTIONS: A single intravenous dose of morphine (0.025 mg/kg) and lidocaine (1.5 mg/kg) were given separately 12-36 h after admission, and arterial blood samples for serum drug levels were taken. MEASUREMENTS AND RESULTS: Morphine pharmacokinetics were studied in 30 patients. The clearance (Cl) was found to be 5.7+/-2.3 ml/kg per min, volume of distribution of the central compartment (Vc) 0.16+/-0.12 l/kg and volume of distribution at steady state (Vss) 1.08+/-0.69 l/kg. These values are lower then those described previously for healthy volunteers (33.5+/-9 ml/kg per min, 1.01+/-0.31 l/kg, and 5.16+/-1.4 l/kg, respectively), and similar to those described in trauma and burned patients. Lidocaine pharmacokinetics were tested in 24 subjects. The Cl was 6.9+/-3.8 ml/kg per min, Vc 0.25+/-0.1 l/kg and Vss 0.78+/-0.26 l/kg. These values are not different from parameters published previously for healthy volunteers (10 ml/kg per min, 0.53 l/min and 1.32 l/min, respectively). No correlation was found between clinical variables and pharmacokinetic parameters of both drugs (ANOVA). CONCLUSIONS: Both morphine and lidocaine have a reduced volume of distribution in critically ill patients. The normal lidocaine clearance indicates preserved hepatic blood flow and suggests that other mechanisms are involved in the reduced morphine clearance. These findings may have application for the treatment of ICU patients.