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Biomedical subjects

Dan Benhamou

Publications and source records attributed to Dan Benhamou.

At least 55 records · Page 3Linked to original sources
PubMed2004

[Preliminary results from the SFAR-iNSERM inquiry on anaesthesia-related deaths in France: mortality rates have fallen ten-fold over the past two decades].

A National Confidential Inquiry was conducted among death certificators and anaesthetists. A sample of 3700 death certificates from the year 1999 were randomised, after selection of words relating to anaesthesia, surgery, obstetrics, endoscopy, procedural complications, and violent death, with different ratios according to the words and the age; 500 additional certificates relating to deaths in hospital were evaluated to verify the exhaustive nature of the mention of procedures in the certificates. The certificator was sent a simplified form each time the role of the procedure in death could not be excluded (response rate 97%). The anaesthetist was offered a peer review whenever the role of the anaesthetic procedure could not be ruled out (uptake rate 97%). An expert committee analysed the (anonymized) files to determinate the mechanism of the accident and its relationship to anaesthesia. The mortality rates were estimated from the 1996 "Anaesthesia in France" survey. The annual rates of deaths that were totally or partially related to anaesthesia were respectively 7 (CI95%: 2-12) and 47 (31-63) per million. These mortality rates increased with comorbidity, from 4 per million in patients of ASA physical status class 1 to 554 per million in class 4. Similarly, these rates increased with age, from 7 per million in patients less than 45 years old, to 32 in older patients. Most accidents were of ventilatory (38%: airway management: 6%, aspiration pneumonitis: 9%), cardiac (31%: ischaemia: 25%, including anaemia-related), and vascular origin (30%: hemorrhage: 12%, vasodilation by spinal anaesthesia: 6%, anaphylaxis: 3%). The main surgical procedures involved were orthopaedic (50%: hip fracture, haemorrhagic surgery) and digestive (24%: occlusion, peritonitis). INSERM had previously collected data on complications associated with anaesthesia between 1978 and 1982: the annual rates of deaths that were totally or partially related to anaesthesia were respectively 76 and 263 per million. Compared to these previous data, the anaesthesia-related mortality rate fell ten-fold over the last two decades, while the number of anaesthetic procedures at least doubled. In addition, the number of procedures involving old people and patients with poor physical status was multiplied by four. It seems logical to attribute these results to safety and practice guidelines published after the previous inquiry. Progress remains to be made: the present rate of 1/145000 will serve as a basis for systematic analysis of accidents.

Aged↗
PubMed2003

A randomized sequential allocation study to determine the minimum effective analgesic concentration of levobupivacaine and ropivacaine in patients receiving epidural analgesia for labor.

BACKGROUND: This study was designed to determine and compare the minimum local analgesic concentrations of levobupivacaine and ropivacaine when used in epidural obstetric analgesia. METHODS: In a double-blind study, healthy women requiring epidural analgesia for labor pain were randomized to receive either ropivacaine or levobupivacaine. Drugs were administered as a 20-ml epidural bolus. The concentration of each started at 0.11% and increased or decreased at intervals of 0.01%, depending on the response of the previous patient, using the technique of up-down sequential allocation. Minimum local analgesic concentrations were calculated using the formula of Dixon and Massey. Efficacy was assessed using visual analog pain scores and motor and sensory block assessments, and safety was assessed by recording maternal and fetal/neonate vital signs and adverse events. RESULTS: Forty-seven patients received levobupivacaine, and 47 received ropivacaine. Minimum local analgesic concentrations for levobupivacaine (0.077%; 95% CI, 0.058-0.096%) were lower than those for ropivacaine (0.092%; 95% CI, 0.082-0.102%). The 0.015% difference was not statistically significant. There was no notable difference between treatment groups in the proportion of patients reporting drug-related adverse events. CONCLUSIONS: Levobupivacaine was 19% more potent than ropivacaine and provided similar safety results.

Adult↗
PubMed2002

Audit of an early feeding program after Cesarean delivery: patient wellbeing is increased.

PURPOSE: Early feeding is well tolerated after Cesarean delivery. However, patient wellbeing and nurses' attitudes toward implementation of early feeding have rarely been investigated. METHODS: A quality-assurance program of 18 months duration was implemented because evaluation of traditional practice demonstrated significant deficiencies (phase I). Drinking was then allowed within one hour and feeding within six to eight hours after delivery. Gradual dietary expansion followed according to a detailed program. Three consecutive evaluations (phase II-IV) were performed: 1) to measure implementation by the ward nurses; 2) to record the type of food and the volume of water effectively received; 3) to evaluate patients' gastrointestinal tolerance and patients' levels of hunger and thirst and patients' overall satisfaction. RESULTS: In phase I, 60% of patients received nothing by mouth and 28% received only water on the day of surgery (D0). Moderate or severe hunger and thirst were seen in a large portion of these patients (D0, hunger: 38%, thirst: 63%, D1, hunger: 40%, thirst: 28%). Introduction of the program significantly improved patient wellbeing as well as patient satisfaction. No side effects were encountered. CONCLUSION: Hunger and thirst are frequently encountered after Cesarean delivery when patients are allowed to eat only after return of the first flatus. By using a quality-assurance program, it was possible to reduce the incidence and the severity of these distressing symptoms and to improve patients' satisfaction while no side effects were encountered. These beneficial effects were maintained in phase IV suggesting a high acceptance rate from the nursing staff.

Cesarean Section↗
PubMed2002

The clinical efficacy and pharmacokinetics of intraperitoneal ropivacaine for laparoscopic cholecystectomy.

UNLABELLED: Postoperative pain after laparoscopic surgery is less than after laparotomy, and patients may benefit from an intraperitoneal injection of local anesthetic. Thirty-seven ASA physical status I or II patients received in double-blinded fashion 20 mL of 0.9% saline solution (placebo), ropivacaine 0.25% (Rop 0.25%), or ropivacaine 0.75% (Rop 0.75%) immediately after trocar placement and at the end of surgery. We measured pain and morphine consumption until 20 h after surgery. Plasma ropivacaine concentrations were measured. The three groups were comparable for shoulder pain, parietal pain, and incidence of side effects. Visceral pain at rest, during cough, and on movement and total consumption of morphine were significantly smaller in Groups Rop 0.25% and Rop 0.75% when compared with Placebo. Although no adverse effect occurred in any patient, the largest dose led to large plasma concentrations of ropivacaine (2.93 +/- 2.46 microg/mL and 3.76 +/- 3.01 microg/mL after the first and second injection, respectively). We conclude that intraperitoneal administration of ropivacaine before and after surgery significantly decreases postoperative pain. Because the smaller dosage (2 x 50 mg) provided similar analgesia and was associated with significantly smaller plasma concentrations than the larger dosage (2 x 150 mg), this smaller dosage seems more appropriate. IMPLICATIONS: Intraperitoneal ropivacaine 100 mg injected during laparoscopic cholecystectomy significantly decreased postoperative pain when compared with injection of intraperitoneal placebo. At this dose, plasma concentrations remained in the nontoxic range,

Amides↗
PubMed2002

The hemodynamic effects of pediatric caudal anesthesia assessed by esophageal Doppler.

UNLABELLED: Pediatric caudal anesthesia is an effective method with an infrequent complication rate. However, little is known about its cardiovascular consequences. Transesophageal Doppler, a noninvasive method, provides the opportunity for a reappraisal of the hemodynamic effects of this technique. After parental informed consent, we studied 10 children aged 2 mo to 5 yr who were scheduled for lower abdominal surgery. General anesthesia was induced using sevoflurane and was followed by the insertion of a transesophageal Doppler probe. Caudal anesthesia was performed using 1 mL/kg of 0.25% bupivacaine with 1/200,000 epinephrine. Hemodynamic variables were collected before and after caudal anesthesia. No complications arose during insertion of the probe. The mean time between the two sets of measurements was 15 min. Heart rate, systolic, diastolic, and mean arterial blood pressures were not modified by caudal anesthesia. Descending aortic blood flow increased significantly from 1.14 to 1.92 L/min. (P = 0.0002). Aortic ejection volume increased from 8.5 to 14.5 mL (P = 0.0002). Aortic vascular resistances decreased from 6279 to 3901 dynes. s(-1) x m(-5) (P = 0.005). Caudal anesthesia did not affect heart rate and mean arterial blood pressure but induced a significant increase in descending aortic blood flow. IMPLICATIONS: Although pediatric caudal anesthesia does not alter heart rate nor arterial blood pressure, significant changes occur in regional blood flow distribution. Descending aortic blood flow increases significantly after caudal anesthesia, whereas lower body vascular resistances decrease.

Anesthesia, Caudal↗
PubMed2002

Difficult endotracheal intubation in patients with sleep apnea syndrome.

UNLABELLED: Although sleep apnea syndrome (SAS) is common, studies assessing the anesthetic management of these patients are rare and consist mainly of case studies. We performed a retrospective case-control study to determine the incidence of difficult intubation in SAS patients and to determine the relationship between the severity of SAS and the occurrence of difficult intubation. Among 113 patients included (36 and 77 in the SAS and control groups, respectively), difficult intubation occurred more often in SAS patients than in controls (21.9% versus 2.6%, respectively; P < 0.05). No relationship was found between the severity of SAS and the occurrence of difficult intubation. Disappointingly, no single factor was associated with the occurrence of difficult intubation in SAS patients. We conclude that SAS is a risk factor for difficult intubation. IMPLICATIONS: Because patients with sleep apnea syndrome have an increased risk of difficult endotracheal intubation and may present with cardiovascular disease, preoperative preventive measures should be undertaken to avoid untoward events.

Adolescent↗
PubMed2002

Intrathecal ropivacaine in rabbits: pharmacodynamic and neurotoxicologic study.

BACKGROUND: Ropivacaine is available for spinal or intrathecal use in humans, although data on neurotoxicity after spinal injection are not yet available. The authors experimentally determined the relationship between doses of intrathecal ropivacaine and spinal effects and local neurotoxic effects. METHODS: Eighty rabbits equipped with an intrathecal lumbar catheter were studied. Sixty were randomly assigned to receive 0.2 ml of intrathecal solutions as a sole injection of: 0.2%, 0.75%, 1.0%, and 2.0% ropivacaine (doses from 0.4-4.0 mg; groups R0.2 to R2.0), 5.0% lidocaine (10 mg; group L), or 0.9% NaCl as control (group C). Twenty other rabbits received either repeated injections of 0.2 ml of 0.2% ropivacaine every 2 days during 2 weeks (total dose of 2.8 mg; group RINT); or a continuous intrathecal infusion of 0.2% ropivacaine at the rate of 1.8 ml/h over 45 min (2.7 mg; group RCONT). Injection rate was 30 s in all groups except Rcont. Time to onset, duration and extent of motor block, and variations of mean arterial blood pressure were recorded in all groups. Somatosensory evoked potentials were also recorded in group RCONT and RINT. Seven days after the last intrathecal injection spinal cord and nerves were sampled for histopathologic study. RESULTS: In groups R0.2 and RINT, the lowest dose of ropivacaine induced a clinically visible spinal block in only 50% of rabbits, but SEPs recorded in group RINT were decreased by 70% in the lumbar dermatome. Complete motor block was observed with doses greater than 1.5 mg of ropivacaine (group RCONT and R0.75 to R2.0). Onset time was shorter and duration of block increased as doses of ropivacaine increased. Significant hypotension was observed only with 4.0 mg of ropivacaine (concentration of 2.0%). Complete paralysis and hypotension were observed with 5.0% lidocaine. No neurologic clinical lesion was observed in rabbits receiving saline or ropivacaine within the 7 days after the last intrathecal injection, and histopathologic study revealed no sign of neurotoxicity in these groups. In contrast, intrathecal lidocaine induced clinical and histopathologic changes. CONCLUSION: Ropivacaine induced dose-dependent spinal anesthesia, and did not induce any neurotoxicologic lesion in this experimental animal model.

Amides↗
PubMed2002

Cortisol response to corticotropin stimulation in trauma patients: influence of hemorrhagic shock.

BACKGROUND: An abnormal adrenocortical function and a vasopressor dependency have been demonstrated during septic shock. Because trauma and hemorrhage are the leading causes of noninfectious inflammatory syndromes, the goal of this study was to assess the adrenal reserve of trauma patients and its relation with clinical course. METHODS: Cortisol response to an intravenous corticotropin bolus was obtained in 34 young trauma patients (Injury Severity Score =29.1 +/- 7.3) at the end of the resuscitative period ("early phase") and at the end of the first posttraumatic week ("late period"). Cortisol response less than +9 g/dl defined an impaired adrenal function, and the corresponding patient was called a nonresponder. According to the early response, hemorrhagic shock, circulating interleukin-6, need for vasopressor therapy, subsequent organ dysfunction and infection, and outcomes were studied. RESULTS: Sixteen patients (47%) were nonresponders at the end of the early phase. Hemorrhagic shock was more frequent (69 vs. 28%; = 0.037) and interleukin-6 concentrations were higher (728 +/- 589 vs. 311 +/- 466 pg/ml; = 0.048) in these patients. The early cortisol responses were negatively correlated with the concomitant interleukin-6 serum concentrations (r(2) = 0.298; = 0.003). Four early nonresponders (and shock patients) remained nonresponders during the late phase (25%). Morbidity and mortality were similar in early nonresponders and responders. The duration of norepinephrine treatment and the total amount of infused drug were significantly higher in early nonresponders. CONCLUSIONS: A sustained impairment of adrenal reserve is frequently observed in trauma patients. This abnormal cortisol response to corticotropin stimulation is related with the inflammatory consequences of hemorrhagic shock and is followed by a prolonged vasopressor dependency.

Adolescent↗
PubMed2002

Major complications of regional anesthesia in France: The SOS Regional Anesthesia Hotline Service.

BACKGROUND: Several previous surveys have estimated the rate of major complications that occur after regional anesthesia. However, because of the increase in the use of regional anesthesia in recent years and because of the introduction of new techniques, reappraisal of the incidence and the characteristics of major complications is useful. METHODS: All French anesthesiologists were invited to participate in this 10-month prospective survey based on (1) voluntary reporting of major complications related to regional anesthesia occurring during the study period using a telephone hotline service available 24 h a day and managed by three experts, and (2) voluntary reporting of the number and type of regional anesthesia procedures performed using pocket booklets. The service was free of charge for participants. RESULTS: The participants (n = 487) reported 56 major complications in 158,083 regional anesthesia procedures performed (3.5/10,000). Four deaths were reported. Cardiac arrest occurred after spinal anesthesia (n = 10; 2.7/10,000) and posterior lumbar plexus block (n = 1; 80/10,000). Systemic local anesthetic toxicity consisted of seizures only, without cardiac toxicity. Lidocaine spinal anesthesia was associated with more neurologic complications than bupivacaine spinal anesthesia (14.4/10,000 vs. 2.2/10,000). Most neurologic complications were transient. Among 12 that occurred after peripheral nerve blocks, 9 occurred in patients in whom a nerve stimulator had been used. CONCLUSION: This prospective survey based on a free hotline permanent telephone service allowed us to estimate the incidence of major complications related to regional anesthesia and to provide a detailed analysis of these complications.

Acute Disease↗
PubMedDate not supplied

Bilateral lower limb hypoesthesia after radical prostatectomy in the hyperlordotic position under general anesthesia.

PURPOSE: To report a case of postoperative bilateral lower limb hypoesthesia occurring after surgery under general anesthesia in the hyperlordotic position for radical prostatectomy. The possible pathophysiologic mechanisms are discussed. CLINICAL FEATURES: This 52-yr-old patient was slightly overweight and was on fenofibrate for hypercholesterolemia. He had no history of cardiovascular disease. Arterial blood pressure was overall well maintained except for a very transient hypotension at surgical incision. Blood loss was moderate and did not require transfusion. Soon after recovery, the patient complained of paresthesia in both legs and neurological examination revealed bilateral lower limb hypoesthesia, compatible with an incomplete medullar syndrome at the level of T12-L1. On postoperative day one, a plain magnetic resonance imaging scan demonstrated a hyperintense signal in the spinal cord from T8 to T9 on T2-weighted images consistent with ischemia of the spinal cord whereas the heterogeneous aspect of the spinal cord was due to an unusually high fat content of the epidural space. Neurological signs improved progressively and one week later the patient had recovered normal sensory functions of both lower limbs. CONCLUSION: Although arterial ischemia is the most common cause of postoperative spinal cord injury, other mechanisms may be invoked. We raise the possibility that a combination of intraoperative risk factors (hypotension, excessive postural changes) with anatomic predispositions (increased epidural venous pressure or fat content, previous bone disease) can produce arterial and/or venous ischemia of the spinal cord.

Humans↗
PubMedDate not supplied

Ultrasound guidance for difficult lateral popliteal catheter insertion in a patient with peripheral vascular disease.

OBJECTIVE: Interest in ultrasound-guided nerve block is increasing, but clinical utility still is being determined. We report a case in which ultrasound imaging aided nerve localization during popliteal block. CASE REPORT: We report a case in which failure of nerve stimulation to locate the sciatic nerve at the popliteal fossa in a patient with underlying neuropathy was overcome by ultrasound guidance, which allowed quick and easy catheter placement. After failure of the stimulation technique, ultrasound permitted us to observe advancement of the needle, placement of the catheter, and spread of local anesthetic around the nerve. CONCLUSION: Ultrasound guidance can facilitate lateral popliteal catheter insertion in patients in whom electrolocation has failed.

Amides↗
PubMedDate not supplied

Medial canthus single-injection peribulbar anesthesia: a prospective randomized comparison with classic double-injection peribulbar anesthesia.

BACKGROUND AND OBJECTIVES: The authors report the first prospective randomized comparison of the medial canthus single-injection peribulbar anesthesia (also called caruncular anesthesia) with the classic double-injection peribulbar technique. METHODS: One hundred patients scheduled for cataract surgery were randomly assigned to either a single medial canthus injection or a double peribulbar injection of mepivacaine 2%. The amount of anesthetic agent injected was clinically adapted to each patient. Akinesia, volume injected, pain, reinjections, and complications were assessed after the procedure. RESULTS: The medial canthus single-injection peribulbar anesthesia was significantly less painful and required less anesthetic agent than the double-injection peribulbar anesthesia. Akinesia score and the reinjection rate were similar in the 2 groups, whereas chemosis was significantly more frequent in the double-injection group. CONCLUSIONS: Medial canthus single-injection peribulbar anesthesia appears to be an effective alternative to the usual double-injection peribulbar anesthesia.

Aged↗
PubMedDate not supplied

Resident versus staff anesthesiologist performance: coracoid approach to infraclavicular brachial plexus blocks using a double-stimulation technique.

OBJECTIVES: Infraclavicular brachial plexus block with double stimulation (ICB) is a safe technique for upper-limb anesthesia. However, the experience of learning this technique by anesthesiology residents has not been reported. The aim of this study was to compare staff with resident anesthesiologists in the performance of ICB. METHODS: Patients scheduled for orthopedic surgery of the upper limb were included in a prospective, comparative, randomized study and were given ICB by either staff anesthesiologist (Group S, n = 110 patients) or resident anesthesiologist (Group R, n = 110 patients). RESULTS: Time to perform the block was 3.9 minutes (95% confidence interval [CI 95%] = 3.5 to 4.3) for Group S and 5.8 minutes (CI 95% = 5.2 to 6.4) for Group R (P < .05). The onset time was 14.4 minutes (CI 95% = 13.5 to 15.3) for Group S and 15.9 minutes (CI 95% = 14.7 to 17.1) for Group R (P = NS). Success rate was 93% for Group S and 90% for Group R (P = NS). Supplementation was performed in 8 patients in Group S versus 11 patients in Group R (P = NS). No patient needed general anesthesia. One self-limited vascular puncture was made in Group S versus 3 in Group R (P = NS). CONCLUSION: This report determines whether residents can perform this technique with comparable efficiency compared with staff. We conclude that ICB should be taught as part of all resident training programs.

Adult↗