André Lienhart

Survey of Anesthesia-related Mortality in France

Background:This study describes a nationwide survey that estimates the number and characteristics of anesthesia-related deaths for the year 1999. Methods:Death certificates from the French national mortality database were selected from the International Classification of Diseases, Ninth Revision codes using a variable sampling fraction. Medical certifiers were sent a questionnaire (response rate, 97%), and the anesthesiologist in charge was offered a peer review (acceptance rate, 97%). Files were reviewed to determine the mechanism of each perioperative death and its relation to anesthesia. Mortality rates were calculated using the number of anesthetic procedures estimated from a national 1996 survey and compared with a previous (1978–1982) nationwide study. Results:Among the 4,200 certificates analyzed, 256 led to a detailed evaluation. The death rates totally or partially related to anesthesia for 1999 were 0.69 in 100,000 (95% confidence interval, 0.22–1.2 in 100,000) and 4.7 in 100,000 (3.1–6.3 in 100,000), respectively. The death rate increased from 0.4 to 55 in 100,000 for American Society of Anesthesiologists physical status I and IV patients, respectively. Rates increased with increasing age. Although concerns regarding aspiration of gastric contents remain, intraoperative hypotension and anemia associated with postoperative ischemic complications were the associated factors most often encountered. Deviations from standard practice and organizational failure were often found to be associated with death. Conclusion:In comparison with data from a previous nationwide study (1978–1982), the anesthesia-related mortality rate in France seems to be reduced 10-fold in 1999. Much remains to be done to improve compliance of physicians to standard practice and to improve the anesthetic system process.

French survey of anesthesia in 1996.

BACKGROUND To identify the growth in the number of anesthetic procedures since 1980 and the changes in the practice of anesthesia, the present survey was designed to collect and analyze the anesthetic activity performed in France in 1996, from a representative sample collected in all French hospitals and clinics. METHODS This study, initiated by the French Society of Anesthesia and Intensive Care, collected information that included the characteristics of patients (age, sex, American Society of Anesthesiologists status), the techniques of anesthesia, and the nature of the procedure for which anesthesia was required. All French private, public, and military hospitals were asked to participate in the survey. In each hospital in the country, all anesthetic procedures were documented and collected during 3 consecutive days, chosen at random during a 12-month period, to obtain a representative sample of the annual activity. All data were analyzed at the INSERM (National Institute of Health and MEDICAL RESEARCH: At the conclusion of the study, 5% of hospitals were randomly assigned to be audited to check for missing data and errors. The rate of anesthetic activity was calculated as the ratio between the annual number of anesthetic procedures and the number of the general population in the same age group. RESULTS The participation rate of hospitals was 98%. The analysis of the 62,415 collected questionnaires allowed extrapolation of the anesthetic activity to 7,937,000 anesthetic procedures (95% confidence interval, +/- 387,000) performed in France in 1996. Thus, the annual rate of anesthetic procedures was 13.5 per 100 population, varying between 5.4 per 100 in girls aged 5-14 yr and 30.2 per 100 in men aged 75-84 yr. Surgery was involved in 71% of anesthesia cases. Regional anesthesia alone was performed in 20% of all surgical cases and was combined with general anesthesia in 3% of additional cases. Anesthesia for obstetric procedures represented 9% of all cases. Seventy-six percent of all anesthetic procedures started between 12:00 A.M. and 7:00 A.M. were related to obstetric activities. CONCLUSION In comparison with a previous study, the present survey shows that the number of anesthetic procedures has increased by 120% since 1980, and the rate of anesthetic procedures increased from 6.6 to 13.5 per 100 population, the major changes being observed in patients aged > or = 75 yr and in those with an American Society of Anesthesiologists physical status of 3. In the same time period, the number of regional anesthetic procedures increased 14-fold. In obstetrics, the practice of epidural analgesia extended from 1.5% to 51% of all deliveries of the country.

Prevention of Intraoperative Hypothermia by Preoperative Skin-Surface Warming

Background:Intraoperative hypothermia initially results from internal redistribution of heat facilitated by anesthesia-induced vasodilatlon. Preinductlon skin-surface warming minimizes postinduction hypothermia in anesthetized volunteers. However, its efficacy might be reduced in surgical situations, because of multiple sources of heat loss. Methods:Intraoperative core and mean skin temperatures were measured during total hip arthroplasty in 16 patients, randomly assigned to be covered preoperatlvely with a warming blanket for ≥90 min (prewarmed group) or not covered (unwarmed group). Results:During the first hour of anesthesia, core temperature decreased more than twice as much in the unwarmed group (−0.7 ± 0.1° C; mean ± SE) than in the prewarmed patients (−0.3 ± 0.1° C). At the end of surgery, core temperature was 36.3 ± 0.1° C in the prewarmed group and 35.2 ± 0.2° C in the unwarmed group. During recovery, seven patients obviously shivered in the unwarmed group and none in the prewarmed group. Conclusions:Preanesthetic skin-surface warming reduces the initial postinductlon hypothermia in surgical patients, preventing intraoperative hypothermia and postoperative shivering even for procedures lasting 3 h or longer.

Prominent contribution of portal mesenchymal cells to liver fibrosis in ischemic and obstructive cholestatic injuries.

Liver fibrosis is produced by myofibroblasts of different origins. In culture models, rat myofibroblasts derived from hepatic stellate cells (HSCs) and from periductal portal mesenchymal cells, show distinct proliferative and immunophenotypic evolutive profiles, in particular regarding desmin microfilament (overexpressed vs shut-down, respectively). Here, we examined the contributions of both cell types, in two rat models of cholestatic injury, arterial liver ischemia and bile duct ligation (BDL). Serum and (immuno)histochemical hepatic analyses were performed at different time points (2 days, 1, 2 and 6 weeks) after injury induction. Cholestatic liver injury, as attested by serum biochemical tests, was moderate/resolutive in ischemia vs severe and sustained in BDL. Spatio-temporal and morphometric analyses of cytokeratin-19 and Sirius red stainings showed that in both models, fibrosis accumulated around reactive bile ductules, with a significant correlation between the progression rates of fibrosis and of the ductular reaction (both higher in BDL). After 6 weeks, fibrosis was stabilized and did not exceed F2 (METAVIR) in arterial ischemia, whereas micronodular cirrhosis (F4) was established in BDL. Immuno-analyses of α-smooth muscle actin and desmin expression profiles showed that intralobular HSCs underwent early phenotypic changes marked by desmin overexpression in both models and that the accumulation of fibrosis coincided with that of α-SMA-labeled myofibroblasts around portal/septal ductular structures. With the exception of desmin-positive myofibroblasts located at the portal/septal-lobular interface at early stages, and of myofibroblastic HSCs detected together with fine lobular septa in BDL cirrhotic liver, the vast majority of myofibroblasts were desmin-negative. These findings suggest that both in resolutive and sustained cholestatic injury, fibrosis is produced by myofibroblasts that derive predominantly from portal/periportal mesenchymal cells. While HSCs massively undergo phenotypic changes marked by desmin overexpression, a minority fully converts into matrix-producing myofibroblasts, at sites, which however may be important in the healing process that circumscribes wounded hepatocytes.

Oxygen uptake during recovery following naloxone. Relationship with intraoperative heat loss.

The increased metabolic and respiratory demand during naloxone recovery from opioid-based anesthesia could be related to the return of thermoregulation in hypothermic patients and thus be avoided by preventing intraoperative hypothermia. In this study, we measured O2 uptake (VO2) during naloxone-induced recovery in two groups of patients to determine the effect of intraoperative heat loss on postoperative VO2 changes. In seven patients, intraoperative hypothermia was prevented (normothermic group), whereas hypothermia was allowed to develop in seven other patients (hypothermic group). Core and skin temperatures were measured throughout the study to calculate changes in body heat content. Before naloxone antagonism of fentanyl-supplemented anesthesia, core temperature (mean +/- SEM) was 36.8 +/- 0.1 degrees C in the normothermic group and 34.2 +/- 0.2 degrees C in the hypothermic group (P less than 0.001). After titrated administration of naloxone during recovery, VO2 and minute ventilation (VE) increased in the hypothermic group, by 114 +/- 37% and 97 +/- 52% respectively (P less than 0.05), with a three-fold increase in four patients. In the normothermic group, VO2 increased significantly less (25 +/- 5%), without any significant change in VE. The change in VO2 and VE was significantly greater in patients who were hypothermic. VO2 was integrated throughout the recovery period to calculate recovery energy expenditure. Recovery energy expenditure and intraoperative heat loss were highly correlated (r = 0.88; P less than 0.01). This study demonstrates that the metabolic and respiratory stresses associated with naloxone-induced recovery from opioid-based anesthesia depend on the intraoperative heat loss and can therefore be reduced by preventing intraoperative hypothermia.

Pre-induction skin-surface warming minimizes intraoperative core hypothermia.

STUDY OBJECTIVE To test the hypothesis that only one hour of preinduction skin-surface warming decreases the rate at which core hypothermia develops during the first hour of anesthesia. DESIGN Randomized, prospective study. SETTING Operating theater of a university hospital. PATIENTS 16 ASA status I and II adult patients scheduled for laparoscopic cholecystectomy under general anesthesia. INTERVENTIONS Eight patients were assigned to receive forced-air warming for one hour before induction of anesthesia (prewarmed group); the other eight patients were covered only with a wool blanket during a similar preinduction period (control group). MEASUREMENTS AND MAIN RESULTS Tympanic membrane (core) and mean skin-surface temperatures were measured at 15-minutes intervals, starting one hour before induction of anesthesia. Mean skin temperature increased from 34.0 +/- 0.1 C to 37.0 +/- 0.2 degrees C in the pre-warmed group (p < 0.05), but remained unchanged at 34.7 +/- 0.3 degrees C in the control group. Core temperature during the preinduction period did not change significantly in either group. Following induction of anesthesia, core temperature decreased at a rate of 1.1 +/- 0.1 degrees C/hr in the control group, but only 0.6 +/- 0.1 degrees C/hr in the pre-warmed group (p < 0.05). After one hour of anesthesia, six of eight pre-warmed patients had core temperatures of at least 36.5 degrees C, whereas only one of the eight control patients did (p < 0.05). CONCLUSIONS A single hour of preoperative skin-surface warming reduced the rate at which core hypothermia developed during the first hour of anesthesia. Preoperative skin surface warming is particularly helpful during short procedures because redistribution hypothermia is otherwise difficult to treat.

Hemodynamic effects of portal triad clamping in humans.

: The hemodynamic effects of portal triad clamping (PTC) were studied in 48 adult patients scheduled for elective liver resection. Prior to hepatic resection the effects of a short period of PTC (3-5 min) were evaluated in all 48 patients: mean arterial pressure increased 21%, whereas pulmonary capillary wedge pressure and cardiac index decreased 10 and 17%, respectively. Systemic vascular resistance increased 48%. In 34 patients a liver resection was performed during PTC and hemodynamic measurements were repeated throughout the duration of liver ischemia, which ranged from 14 to 68 min. Hemodynamic changes occurred in the first 3 min and persisted thereafter. After releasing the clamp, hemodynamic parameters returned to initial values in 3 min. These results confirm that PTC does not induce the cardiovascular collapse in humans that it does in common laboratory animals and demonstrate that humans tolerate PTC for periods up to 1 hr.

Comparative effects of desflurane and isoflurane on recovery after long lasting anaesthesia

PurposeIncreasing the duration of exposure could lead to amplification of the pharmacokinetic differences between halogenated anaesthetic agents. The aim of our study was to compare anaesthesia recovery after desflurane and isoflurane, administered for more than three hours.MethodsAfter informed consent, patients were randomly assigned to either desflurane (n = 15) or isoflurane (n = 15) groups. At the end of surgery, halogenated agents were discontinued and fresh gas flow was increased to 6 l · min−1 oxygen 100%.ResultsMean anaesthesia duration was 292 ± 63 and 304 ± 91 min in the desflurane and isoflurane groups respectively. After desflurane and isoflurane discontinuation, the time to opening eyes was 12 ± 7 and 24 ± 11 min respectively (P < 0.001); to squeeze fingers at command was 17 ± 11 and 35 ± 19 min (P < 0.001); to extubation was 16 ± 6 and 33 ± 13 min (P < 0.001); to give their name was 22 ± 12 and 43 ± 21 min (P < 0.001); to achieve a Steward score of 6 was 28 ± 16 and 57 ± 33 min (P < 0.001), to be fit for discharge from the recovery room was 46 ± 19 and 81 ± 37 min (P < 0.003). Ranges of times to reappearance of recovery variables in the desflurane group were less than those after isoflurane (P < 0.05).ConclusionAfter long duration anaesthesia lasting up to three hours, desflurane allowed recovery and extubation in approximately half the time required by isoflurane. Less variability in results suggests better predictability of recovery with desflurane.RésuméObjectifLes différences pharmacodynamiques entre les agents halogènes sont amplifiées par la durée d’administration. Ce travail compare les paramètres de réveil après une anesthésie supérieure à trois heures avec de l’iso-flurane ou du desflurane.MéthodeAprès consentement éclairé, les patients ont été répartis par tirage au sort pour recevoir de l’isoflurane (n = 15) ou du desflurane (n = 15). Au dernier point de suture cutanée, l’administration d’agent halogène était stoppée et le débit de gaz frais porté à 6 l · min−1 d’oxygène.RésultatsLa durée d’anesthésie a été de 292 ± 63 et 304 ± 91 min pour le desflurane et l’isoflurane respectivement. Le délai pour l’ouverture des yeux a été de 12 ± 7 et 24 ± 11 min (P < 0.001); pour serrer les mains à la demande de 17 ± 11 et 35 ± 19 min (P < 0.001); pour l’extubation de 16 ± 6 et 33 ± 13 min (P < 0.001); pour donner son nom de 22 ± 12 et 43 ± 21 min (P < 0.001); pour récupérer un score de Steward à 6 de 28 ± 16 et 57 ± 33 min (P < 0.001); pour avoir l’autorisation de sortie de salle de réveil de 46 ± 19 et 81 ±37 min (P < 0.003) pour le desflurane et l’isoflurane respectivement.ConclusionAprès une anesthésie supérieure à trois heures, le desflurane permet un réveil et une extubation approximativement deux fois plus rapide que l’isoflurane. La plus faible variabilité des valeurs suggère une meilleure prédictibilité des paramètres de réveil avec le desflurane.

Parietal analgesia decreases postoperative diaphragm dysfunction induced by abdominal surgery: a physiologic study.

Background and Objectives: The postoperative analgesic strategy may influence the magnitude of the postoperative diaphragmatic dysfunction (PODD) induced by abdominal surgery. The purpose of this physiologic study was to evaluate the effect of continuous preperitoneal wound infusion (CPWI) of ropivacaine on PODD after open colorectal surgery. Methods: Twenty patients with American Society of Anesthesiologists physical status I or II undergoing open colorectal surgery were prospectively included during 2 consecutive 2-month periods. During the first period, we evaluated 10 consecutive patients who received conventional parenteral analgesia (intravenously administered morphine via patient-controlled analgesia and acetaminophen) without parietal analgesia (control group). These patients were compared with 10 consecutive patients who received conventional parenteral analgesia along with parietal analgesia using CPWI of 0.2% ropivacaine at 10 mL/hr for 48 hrs (CPWI group). Diaphragmatic function was assessed preoperatively and at 24 and 48 hrs postoperatively using the sniff nasal inspiratory pressure test (Psniff). Supplemental intravenously administered morphine boluses were administered as needed before Psniff assessments in the control group to reduce differences in pain intensity. Results: Demographic and surgical data did not differ between the 2 groups, nor did preoperative Psniff values (71 cm H2O [SD, 20 cm H2O] vs 65 cm H2O [SD,15 cm H2O] in the control and CPWI groups, respectively). Postoperative Psniff was significantly decreased in the 2 groups, but the reduction was significantly greater in the control group than in the CPWI group both at 24 hrs (−58% [SD, 18%] vs −24% [SD, 19%]; P = 0.001) and at 48 hrs (−44% [SD, 31%] vs -11% [SD, 32%]; P = 0.027). Conclusions: Parietal analgesia delivered via a CPWI of ropivacaine reduces PODD induced by open colorectal surgery.

Complications related to blood transfusion in surgical patients: data from the French national survey on anesthesia-related deaths

T his article reports on studies performed by a group of clinicians and epidemiologists who have worked for a long time in several surveys from which data related to perioperative transfusion are presented here. These surveys were initially aimed at measuring anesthesia-related death and mortality in the perioperative setting. When gathering data we gained some interesting and evolving information related to transfusion.