Andre Lienhart

Continuous preperitoneal infusion of ropivacaine provides effective analgesia and accelerates recovery after colorectal surgery: a randomized, double-blind, placebo-controlled study

Background:Blockade of parietal nociceptive afferents by the use of continuous wound infiltration with local anesthetics may be beneficial in a multimodal approach to postoperative pain management after major surgery. The role of continuous preperitoneal infusion of ropivacaine for pain relief and postoperative recovery after open colorectal resections was evaluated in a randomized, double-blinded, placebo-controlled trial. Methods:After obtaining written informed consents, a multiholed wound catheter was placed by the surgeon in the preperitoneal space at the end of surgery in patients scheduled to undergo elective open colorectal resection by midline incision. They were thereafter randomly assigned to receive through the catheter either 0.2% ropivacaine (10-ml bolus followed by an infusion of 10 ml/h during 48 h) or the same protocol with 0.9% NaCl. In addition, all patients received patient-controlled intravenous morphine analgesia. Results:Twenty-one patients were evaluated in each group. Compared with preperitoneal saline, ropivacaine infusion reduced morphine consumption during the first 72 h and improved pain relief at rest during 12 h and while coughing during 48 h. Sleep quality was also better during the first two postoperative nights. Time to recovery of bowel function (74 ± 19 vs. 105 ± 54 h; P = 0.02) and duration of hospital stay (115 ± 25 vs. 147 ± 53 h; P = 0.02) were significantly reduced in the ropivacaine group. Ropivacaine plasma concentrations remained below the level of toxicity. No side effects were observed. Conclusions:Continuous preperitoneal administration of 0.2% ropivacaine at 10 ml/h during 48 h after open colorectal resection reduced morphine consumption, improved pain relief, and accelerated postoperative recovery.

Mortality related to anaesthesia in France: analysis of deaths related to airway complications*

Death certificates from the French national mortality database for the calendar year 1999 were reviewed to analyse cases in which airway complications had contributed to peri‐operative death. Respiratory deaths (and comas) found in a previous national 1978–82 French survey (1 : 7960; 95% CI 1 : 12 700 to 1 : 5400) were compared with the death rate found in the present one: 1 : 48 200 (95% CI 1 : 140 000 to 1 : 27 500). In 1999, deaths associated with failure of the breathing circuit and equipment were no longer encountered and no death was found to be related to undetected hypoxia in the recovery unit. Deaths related to difficult intubation also occurred at a lower rate than in the previous report (1 : 46 000; 95% CI 1 : 386 000 to 1 : 13 000) in 1978–82 vs 1 : 176 000 (95% CI 1 : 714 000 to 1 : 46 000) in 1999, a fourfold reduction. In most cases, there were both inadequate practice and systems failure (inappropriate communication between staff, inadequate supervision, poor organisation). This large French survey shows that deaths associated with respiratory complications during anaesthesia have been strikingly reduced during this 15‐year period.

Monitoring the onset of neuromuscular block at the orbicularis oculi can predict good intubating conditions during atracurium-induced neuromuscular block.

This study was designed to assess whether monitoring the orbicularis oculi (OO) can predict good tracheal intubating conditions.Fifty patients, ASA grade I or II were studied. Anesthesia was induced with thiopental (5 mg/kg) and fentanyl (3 micro gram/kg). The ulnar and facial nerves were simultaneously stimulated using train-of-four (TOF) stimulations every 10 s. The responses of the adductor pollicis (AP) and the OO were estimated visually. Patients were randomly allocated to receive either atracurium 0.5 mg/kg (n = 30) or 0.3 mg/kg (n = 20). In each group, endotracheal intubation was performed randomly when the OO or the AP was completely blocked. If complete block was not obtained, intubation was performed 300 s after administration of atracurium. Intubating conditions were scored on a 1 to 4 scale. All intubations were performed by the same physician unaware of the dose and the muscular responses. After 0.5 mg/kg, both muscles were completely blocked in all patients. The average onset time (time from the injection of atracurium to the disappearance of all muscular responses after TOF) was shorter at the OO (2.35 +/- 0.12 min) than at the AP (3.59 +/- 0.15 min) (P < 0.001) (mean +/- SD). Endotracheal intubating conditions were comparable in both groups: good or excellent after 0.5 mg/kg. After 0.3 mg/kg, complete block was achieved only 2/20 at the OO and 12/20 at the AP. Intubating conditions were comparable in both groups: poor or inadequate, except in the two patients with complete OO block, for whom conditions were good. It is concluded that OO monitoring can predict good intubating conditions earlier than AP monitoring when using 0.5 mg/kg but not 0.3 mg/kg atracurium. (Anesth Analg 1995;80:360-3)

Nifedipine and intraoperative core body temperature in humans

BackgroundInitial anesthetic-induced hypothermia results largely from core-to-peripheral redistribution of heat. Nifedipine administration may minimize hypothermia by inducing vasodilation well before induction of anesthesia. Although vasodilation would redistribute heat to peripheral tissues, thermoregulatory responses would maintain core temperature. After equilibration, the patient would be left vasodilated, with a small core-to-peripheral temperature gradient. Minimal redistribution hypothermia may accompany subsequent induction of anesthesia, because heat flow requires a temperature gradient. In contrast, similar vasodilation concurrent with anesthetic-induced vasodilation may augment redistribution hypothermia. Accordingly, the authors tested the hypothesis that nifedipine treatment for 12 h before surgery would minimize intraoperative redistribution hypothermia, whereas nifedipine treatment immediately before induction of anesthesia would aggravate hypothermia. MethodsPatients undergoing hip arthroplasty were randomly assigned to: (1) 20 mg long-acting nifedipine orally 12 h before surgery, and 10 mg sublingually 1.5 h before surgery (n = 10); (2) nifedipine 10 mg sublingually just before induction of anesthesia (n = 10); and (3) no nifedipine (control, n = 10). Anesthesia was maintained with isoflurane and 60% nitrous oxide. Administered intravenous fluids were heated, but the patients were not otherwise actively warmed. ResultsCore temperature decreased 0.8° C in the first hour of surgery in the patients given nifedipine the night before and the morning of surgery, which was significantly less than in the control group (1.7° C in the first hour). In contrast, core temperature decreased 2.0° C in the first hour of surgery in the patients given nifedipine immediately before induction of anesthesia. During the subsequent 70–130 min of anesthesia, core temperature decreased at roughly comparable rates in each group. After 130 min of anesthesia, core temperature in the two nifedipine-treated groups differed by 1.6° C, and the temperatures in all three groups differed significantly. ConclusionsVasodilation induced by nifedipine well before induction of anesthesia minimized redistribution hypothermia, presumably by decreasing the core-to-peripheral tissue temperature gradient. In contrast, redistribution hypothermia was aggravated by administration of the same drug immediately before induction of anesthesia. Drug-induced modulation of vascular tone thus produces clinically important alterations in intraoperative core temperature.

Enquête mortalité Sfar–Inserm : analyse secondaire des décès par inhalation de liquide gastrique

Aspiration of gastric contents is a major complication in relation with the practice of anaesthesia. The present article is aimed at describing detailed data related to aspiration which were obtained during the French national survey on anaesthesia-related mortality conducted by both Sfar and CépiDC-Inserm. Information regarding methods of the survey and the main results has been previously published. In brief, the first part of the survey described the number and characteristics of anaesthetic procedures performed in 1996 (denominator). The second survey analysed deaths related to anaesthesia which were identified from death certificates of the calendar year 1999. Because of the numerical importance of aspiration among the causes of deaths, a secondary analysis was undertaken to assess into details factors leading to the occurrence of this complication. Eighty-three cases of death were found related to aspiration, i.e. one-fifth of deaths related completely or partially to anaesthesia, implying a death rate of one for 221,368 general anaesthetic procedures or 4.5 x 10(-6) (95% IC: 0.8 x 10(-6)-14 x 10(-6)). Patients involved were all in a severe clinical condition (ASA> or =3: 92%), very old and often scheduled for urgent abdominal surgery. Two cases of death occurred during colonoscopy but none in obstetric patients. Aspiration almost always occurred during induction of anaesthesia. Analysis of practice patterns disclosed significant deviations from recommendations. French anaesthetists should voluntarily move through a personal and active process toward an improvement of their practice to reduce the incidence of aspiration.

Determinants of systolic pressure variation in patients ventilated after vascular surgery

OBJECTIVE To discover the predominant determinant of systolic pressure variation during positive-pressure ventilation in mechanically ventilated patients after a vascular surgical procedure. DESIGN Case control study. SETTING Postanesthesia care unit at a university hospital. PARTICIPANTS Eleven patients who were sedated during mechanical ventilation after abdominal aortic surgery. INTERVENTIONS Radial arterial pressure and airway pressure were simultaneously recorded. The systolic pressure variation was measured as the mean difference between the maximal and minimal systolic pressure values during five consecutive mechanical breaths. The delta down was measured as the difference between the systolic blood pressure during apnea and the minimal values of the systolic pressure after one mechanical breath. The velocity time integral, which is closely related to stroke volume, was measured throughout the systolic pressure measurements. MEASUREMENTS AND MAIN RESULTS Positive correlation was found between changes in velocity time integral and the magnitude of both systolic pressure variation (r = 0.73) and delta down (r = 0.80). Volume loading did not significantly modify systolic blood pressure. However, it did not significantly decrease systolic pressure variation and delta down. The corresponding changes in velocity time integral provoked by mechanical ventilation decreased significantly as well. CONCLUSIONS The decrease in systolic pressure provoked by positive-pressure inspiration reflects simultaneous decreases in stroke volume. This suggests that a decrease in left ventricular filling, associated with positive-pressure inspiration, is responsible for systolic pressure variation. This finding confirms the interest in considering systolic pressure variation to provide reliable information about the responsiveness of the heart to preload variations.

How can we explain the gap between randomised studies and 'real life' practice in postoperative transfusion triggers? Do we need to change recommended thresholds for transfusion?

At the present time, improvements in blood safety, particularly in terms of transfusion-transmitted viral infections, have tended to trivialise the risks of transfusion, suggesting that the risk of no transfusion or a delay in transfusion appears to be much higher than the risk of transfusion itself. Indeed, in a French survey performed on anaesthesia-related mortality, 1 the estimated number of anaesthetic procedures was 7756121 per year, with a total of 419 deaths totally or partly related to anaesthesia. Several common causes of death were identified, but consequences of haemorrhage and anaemia played a disturbing role. It was estimated from this survey that nearly 100 deaths occur perioperatively in France every year as the result of inadequate blood management. Surprisingly, more deaths occurred which were related partly to delayed or absent blood transfusion, and only a small proportion of complications occurred after an episode of transfusion, emphasising the safety of blood transfusion in contemporary practice. Moreover, 58% of the reported deaths occurred more than 24h after surgery. In the presence of massive blood loss, anaemia can lead to myocardial infarction (MI) and cardiovascular deaths, which are still the most frequent causes of death after noncardiac surgery, as demonstrated in the huge Norwegian Register of more than 60000 elective orthopaedic operations. 2,3 Patients undergoing noncardiac

Facteurs associés à la stratégie transfusionnelle au cours des anesthésies programmées pour arthroplastie de hanche ou de genou en France

GOAL OF THE STUDY To determine over a whole country what are the factors associated with an intraoperative homologous blood transfusion and with the use of autologous techniques (preoperative autologous blood donation: PABD; acute normovolemic hemodilution: ANVH; intraoperative red cell salvage: IRCS). STUDY DESIGN National enquiry using a large representative sample (3 days of anaesthesia in France). METHODS Univariate followed by multivariate analyses of data gathered in 1996 during the survey leaded by the French society of anaesthesia and intensive care (Sfar) and corresponding to 884 scheduled hip and knee prosthesis surgical procedures. RESULTS Factors associated with a decreased use of PABD programme were: 1--old age and high ASA physical status; 2--procedures of short duration. By contrast, an increased use of PABD was associated with anaesthetics in which a closed circuit had been used. Except for a significant association with increasing age and with absence of PABD used, no additional factor was found to be linked with ANVH. No factor among those studied was found related to the use of IRCS. Homologous blood transfusion was more frequently used in ASA > or = 3 patients, in long duration surgeries while its use was decreased in patients with PABD (odds ratio--for reduction by PABD: 4.4 [95% confidence interval: 2.2-8.8]). Homologous blood transfusion was not related to the use of ANVH or IRCS. CONCLUSION These data obtained from a large national survey confirm previously published studies and meta-analyses and are in agreement with current recommendations. An unexpected relation between PABD and closed circuit anaesthesia has been found.

Complications neurologiques de l’anesthésie locorégionale : analyse des expertises et conclusions des CRCI

All the files of complications of regional anaesthesias requiring an expertise for a Regional Commission for Conciliation and Compensation for medical accidents (CRCI) between 2003 and 2008 were analyzed. The objective was to estimate the homogeneity of the appointed experts, their opinions and the opinions of the CRCI. Querying the database, shared by the National Office for Compensation for Medical Accidents (ONIAM) and the CRCI, and identified 40 files corresponding to the selection criteria. The expertise carried out involved an anaesthetist in 27 cases, always registered, either on the national list of the experts in medical accidents, or on one list of court-appointed experts. Conversely, in 13 cases, no specialist performing himself the technique in question was involved in the expertise, and sometimes the expert was registered on any list. Mostly, the non-specialists do not conclude to medical malpractice. This was not the case in a single file, where the anaesthetist sought and obtained the addition of an anaesthetist in a new expertise, which concluded differently. Damages assessed were highly variable, but the given evidence provided to understand why. The CRCI have generally followed the opinions of the experts, except in a few cases where the evidence allowed a different opinion without requiring a new expertise. In conclusion, the abnormalities in the appointment of experts do not seem to have had consequences in terms of damage assessment, but may alter the balance between causes faulty and not faulty, in favour of the latter.

Acute desflurane or sevoflurane exposure on a previously stabilized atracurium-induced neuromuscular block.

Background and objective: The aim of this prospective study was to compare the effect of the administration of desflurane or sevoflurane to a fixed neuromuscular block. Methods: After written consent, 12 patients were anaesthetized with propofol and sufentanil. Atracurium was administered via a continuous infusion in order to obtain 85% twitch depression of the control value assessed by repeated accelerometric stimulation at the adductor pollicis. Once stabilized over the course of 30 min, propofol was discontinued and either desflurane (n = 6) or sevoflurane (n = 6) was delivered at 1 MAC in a mixture of 50% O2 in air. Study parameters were the magnitude and the time of twitch height variations. Results are presented in mean ± SD. Result: Exposure to halogenated agents led to a significant reduction in twitch height with similar magnitude between the two agents. However, interaction with desflurane showed an initial and transient rise (35 ± 22%) in twitch height before subsequent depression occurred. The time to reach 50% of the signal depression in the desflurane group was significantly delayed (25 ± 7 vs. 11 ± 4 min in the sevoflurane group; P < 0.01). Conclusions: On a stable neuromuscular block elicited by continuous infusion of atracurium, the abrupt administration of desflurane or sevoflurane reduces the accelerometric responses of the adductor pollicis in a similar way. This potentiating effect is produced faster after sevoflurane than after desflurane. With desflurane, a biphasic effect (of a transient and moderate increase followed by depression of the signal) was recorded.