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Biomedical subjects

D Benhamou

Publications and source records attributed to D Benhamou.

At least 73 records · Page 4Linked to original sources

Resveratrol decreases hyperalgesia induced by carrageenan in the rat hind paw.

The effect of resveratrol, an aryl hydrocarbon receptor (AhR) antagonist, known to inhibit inducible cyclooxygenase-2 (COX2) and its transcription were examined in a model of hyperalgesia induced by carrageenan in the rat. Pretreatment with resveratrol did not reverse swelling and edema, but reversed the hyperalgesia induced by local tissue injury provoked by carrageenan. This reversal, occurring at resveratrol concentrations as low as 2 mg/kg, lasted for at least 48 hours. The link with COX2 activity inhibition and COX2 gene transcription, as well as a potential AhR inhibitory effect, remain to be established.

Animals↗

[Gas embolism during radical nephrectomy by retroperitoneal laparoscopy].

A case of CO2 gas embolism occurring during retroperitoneal laparoscopic right radical nephrectomy in a 70-year-old-woman is reported. Patient's outcome was excellent after venous clamping, fluid loading and application of a positive and expiratory pressure. Gas embolism is a well documented complication of laparoscopic surgery, but has been rarely described in retroperitoneal laparoscopy for urologic procedure. The retroperitoneal surgical site, the major surgical procedure with vessel manipulation and the left lateral position seem to be the risk factors for gas embolism in this case.

Aged↗

[Blood transfusion in adults: description of a quality assurance program].

OBJECTIVES: In 1995, a fatal transfusion complication led to the development of a quality-assurance programme (QAP). Initial analysis showed important deficiencies in practice patterns for both nurses and physicians. No written guidelines had been previously produced. STUDY DESIGN: Evaluation of practice patterns and quality-assurance programme. METHODS: A QAP was prepared and implemented, a booklet describing completely the transfusion process and institutional policies and providing practical information was edited and the medical and non-medical personnel was informed and trained on a regular basis. Implementation was evaluated during a three-year period by measuring previously defined surrogate endpoints of the quality of the transfusion process. RESULTS: Implementation became rapidly close to 100% either for well-accepted requirements (i.e. patient's identity reporting on transfusion forms) or when physicians were highly motivated (i.e. autologous blood transfusion). For other indicators, implementation progressed more slowly (i.e. traceability of labile blood products) although significant efforts were made to improve the computerised system of data collection and although hospital administration showed a very positive behaviour. Finally, other indicators showed only partial implementation. Several practical barriers (perceived lack of time, excessive increase in writing requirements) were described for transfusion checklist or transfusion prescription form but more in-depth insufficiencies (patients'information) were also observed. CONCLUSION: The success of a change of practice patterns relies on hospital administration positive role, education and feedback, written and immediately available guidelines, employment of specially trained personnel, long-standing actions. Future accreditation of hospitals based on well-defined and well-implemented procedures will also be a major help to increase the quality of the transfusion process.

Adult↗

[Maternal serum anti-D antibody concentration monitoring and transfusion practices in obstetrics in France: a preliminary study].

OBJECTIVES: In obstetrics, transfusion medicine is involved because of the risk of Rh isoimmunisation and of transfusion at delivery. In France, although these two situations have led to legal or professional recommendations, practices appear to be very different from one institution or one physician to another. STUDY DESIGN: Retrospective study. METHODS: A questionnaire using both direct questions and clinical cases was sent to all members of the French obstetric anaesthetists association (named CARO). RESULTS: One hundred and seventy-eight questionnaires (response rate 17.1%) were returned. Monitoring of anti-D antibody concentrations during pregnancy was performed in accordance with the legal recommendation (14/02/1992) in only 3.9% (Rh+) and 19% (Rh-) of women. Blood samples were performed either too often or too rarely in 39 to 72% of responses. At delivery, an immediate assessment of anti-D antibody concentration was required in almost 100% by the specialist on call in the blood bank while this measurement was considered necessary by only 80% of anaesthetists responding to the questionnaire. The distance between the maternity and the blood bank is greater than 14 km in 19% of responses and the largest time interval reported to obtain red cell concentrates was greater than 145 min in 18% of responses. Autologous blood transfusion is described as being used routinely in only 23% of responses. CONCLUSION: Significant failures in practice patterns and organisation of care are suggested by the responses to this questionnaire. This should stimulate a national debate to improve adequacy of practices to legal and professional recommendations and to review blood distribution to maternities in this country.

Adult↗

[Transfusion of fresh frozen plasma (FFP): audit of prescriptions].

OBJECTIVE: To review fresh frozen plasma (FFP) prescriptions and compare their validity to the legal french guidelines (law of the 12/03/91). STUDY DESIGN: Assessment of all prescriptions has been carried out by a multidisciplinary committee. PATIENTS: All the adults transfused with FFP over one year in a teaching hospital. METHODS: Following each head of department's agreement and following a written notice to all prescribers within the hospital to inform them of the undergoing study and its methodological validation by the board of quality experts, each delivery of FFP was followed by a questionnaire addressed to the prescriber. A board of experts then assessed the significance of the prescription in accordance with the legal requirements after reviewing each medical file. RESULTS: 144 prescriptions to 89 patients were assessed: 23% were judged inappropriate by the experts and 6% did not respect the law. The inappropriate transfusions distribute as follows: intensive care patients (73% of which 80% in multiple organ failure (MOF) and 20% in haemorrhagic shock), cirrhotic patients (12%), patients treated with vitamin K antagonists (12%), obstetric patients (3%). Nine percent of the appropriate transfusions were judged in insufficient volume. The hospital mortality rate was 48%. Among prescribers, 59% were not aware of the law. CONCLUSION: A significant proportion of FFP transfusions is inappropriate. This study, which is the first step of a quality assurance program, will be followed by local recommendations for clinical practice. The current standards of prescribing FFP are more restrictive than those defined in the legal french guidelines.

Blood Component Transfusion↗

[Obstetric analgesia in patients with Klippel-Trenaunay syndrome].

We report three cases of delivery in two parturients with a Klippel-Trenaunay syndrome. These patients have a rare hereditary disorder that results in three main features: haemangiomas, varicose veins, bone and soft tissue hypertrophy. In the absence of angiographic magnetic resonance imaging of the spinal cord and of perispinal tissues, arteriovenous malformations of the central nervous system could not been ruled out. Intravenous sufentanil and pudendal block were used for labour analgesia and vaginal delivery respectively; general anaesthesia was used for uterine revision and for caesarean section.

Adult↗

Haemodynamic changes and vasopressin release are not consistently associated with carbon dioxide pneumoperitoneum in humans.

BACKGROUND: Conflicting haemodynamic changes, suggested to be caused by vasopressin release, have been reported during carbon dioxide (CO2) pneumoperitoneum. However, peritoneal stimulations including open surgery cause both a systemic vasopressor response and a vasopressin release, which are suppressed by opiate administration. Also, a decreased venous return of blood to the heart causes vasopressin release. Furthermore, previous haemodynamic assessments of laparoscopic surgery have been conducted using various anaesthetic regimens, which are likely to have caused various haemodynamic effects. We hypothesised that intraoperative haemodynamic and/or humoral changes would not be observed in association with laparoscopic surgery provided that, (a) normovolaemia is continuously maintained using transoesophageal echocardiographic (TEE) assessment, and (b) adequate depth of general anaesthesia is continuously maintained by bispectral index (BIS) monitoring and high plasma Ievel opiate administration. METHODS: Twenty ASA 1 women undergoing laparoscopic surgery received 10 ml. kg-1 lactated Ringer's solution and thereafter were randomly allocated to receive intraoperatively either 8 ng. ml-1 or 4 ng. ml-1 plasma remifentanil concentrations while BIS was maintained at 50+/-5 by isoflurane alteration. The group receiving 4 ng. ml-1 remifentanil was used as control. Expired CO2 was maintained within a 32-38 kPa range throughout the investigation. Complete TEE haemodynamic investigation was performed before pneumoperitoneum (PP) (T1), and during PP horizontal (T2), with a head-up tilt (T3), with a head-down tilt (T4), horizontal (T5), and PP released (T6). Plasma vasopressin, epinephrine and norepinephrine levels were measured at T1, T3, and T6. ANOVA, Student's t-test and Mann-Whitney U-test were used for statistical analysis. RESULTS: Haemodynamic indices and humoral values did not change significantly within and between remifentanil groups throughout the investigation (all P<0.05). CONCLUSION: Continuous adequate depth of anaesthesia and normovolaemia may have prevented both a humoral and a haemodynamic response, initiated in the peritoneum by the contact with CO2 in previous investigations.

Adult↗

Lack of peripheral analgesia mediated by intraplantar administration of neostigmine in carrageenan-injected rats.

BACKGROUND AND OBJECTIVE: The aim of the study was to test the peripheral analgesic action of neostigmine. Intraplantar administration of neostigmine was studied in carrageenan-injected rats. METHODS: After assessing baseline values (T0) for paw circumference and the paw withdrawal threshold on both hind paws, the right hind paw was injected with 0.2 mL of 1% carrageenan and the left hind paw with 0.2 mL of saline (0.9% NaCl). Two hours later (T1), both hindpaws were tested for inflammation (paw circumference) and for hyperalgesia (paw withdrawal threshold) and subsequently 20 microg of neostigmine was injected in the right hind paw. The paw withdrawal threshold was tested again 10 (T2), 20 (T3) and 60 min (T4) and paw circumference 60 min (T4) after neostigmine injection. RESULTS: Carrageenan injection in the right hindpaw was associated with a decrease in the paw withdrawal threshold reflecting mechanical hyperalgesia (P < 0.001) and an increase in paw circumference reflecting oedema (P < 0.001) in the right hind paw when compared with the left side from T1 to T4. Neostigmine had no effect on paw circumference and the paw withdrawal threshold at measuring points T2, T3 and T4 when compared with T1 in the right hindpaw. CONCLUSION: Our results support the lack of peripheral analgesic effect of neostigmine.

Analgesics↗

Intrathecal baclofen for severe tetanus in a pregnant woman.

A 6-months pregnant woman suffering from severe tetanus was successfully treated with intrathecal baclofen. She delivered a premature but healthy neonate, and was safely discharged home 40 days after the onset of symptoms of tetanus. Specific aspects of intrathecal baclofen therapy in the pregnant woman are discussed.

Adolescent↗

Rapid onset of bronchodilation in COPD: a placebo-controlled study comparing formoterol (Foradil Aerolizer) with salbutamol (Ventodisk).

Formoterol fumarate is a beta2-agonist bronchodilator that combines a fast onset of action with a long duration of action. Its fast onset of action is well documented in asthma but has not been directly compared with that of salbutamol in patients with chronic obstructive pulmonary disease (COPD). This randomized, double-blind, placebo-controlled study was conducted to assess the bronchodilatory effects over the first 3 h after inhalation of single doses of formoterol 24 microg delivered via the Aerolizer dry powder inhaler device (double-blind), or salbutamol 400 microg delivered by a Diskhaler dry powder inhaler (single-blind) in patients with COPD. A total of 24 patients with COPD were randomized [mean age 61.6 +/- 7.8 years, mean forced expiratory volume in 1 sec (FEV1) 1.38 +/- 0.32 l and 45.8 +/- 9.6% of predicted]. Inhalation of formoterol or salbutamol resulted in similar increases in FEV from 0 to 3 h post-dose. Both drugs produced similar bronchodilation by 5 min, which became almost maximal by 30 min. The primary efficacy variable, the area under the curve (AUC) of the FEV increase above predose baseline from 0 to 30 min (AUC(0-30 min)), demonstrated significant effects for formoterol (mean 5.89 +/- 4.67 l min(-1)), and salbutamol (mean 6.06 +/- 4.34 l min(-1)), which were not statistically different from each other but statistically significantly higher (P<0.0001) than that observed with placebo (-0.32 +/- 2.59 l min(-1)). In addition, both formoterol and salbutamol produced similar and rapid increases in forced vital capacity (FVC). In summary, this study confirms the rapid onset of action of formoterol and indicates that the onset of action of formoterol and salbutamol are similar in patients with COPD.

Adult↗

Phenylephrine added to prophylactic ephedrine infusion during spinal anesthesia for elective cesarean section.

BACKGROUND: Because ephedrine infusion (2 mg/min) does not adequately prevent spinal hypotension during cesarean delivery, the authors investigated whether adding phenylephrine would improve its efficacy. METHODS: Thirty-nine parturients with American Society of Anesthesiologists physical status I-II who were scheduled for cesarean delivery received a crystalloid preload of 15 ml/kg. Spinal anesthesia was performed using 11 mg hyperbaric bupivacaine, 2.5 microg sufentanil, and 0.1 mg morphine. Maternal heart rate and systolic blood pressure were measured at frequent intervals. A vasopressor infusion was started immediately after spinal injection of either 2 mg/min ephedrine plus 10 microg/min phenylephrine or 2 mg/min ephedrine alone. Treatments were assigned randomly in a double-blind fashion. The infusion rate was adjusted according to systolic blood pressure using a predefined algorithm. Hypotension, defined as systolic blood pressure less than 100 mmHg and less than 80% of baseline, was treated with 6 mg ephedrine bolus doses. RESULTS: Hypotension occurred less frequently in the ephedrine-phenylephrine group than in the ephedrine-alone group: 37% versus 75% (P = 0.02). Ephedrine (36+/-16 mg, mean +/- SD) plus 178+/-81 microg phenylephrine was infused in former group, whereas 54+/-18 mg ephedrine was infused in the latter. Median supplemental ephedrine requirements and nausea scores (0-3) were less in the ephedrine-phenylephrine group (0 vs. 12 mg, P = 0.02; and 0 vs. 1.5, P = 0.01, respectively). Umbilical artery pH values were significantly higher in the ephedrine-phenylephrine group than in the group that received ephedrine alone (7.24 vs. 7.19). Apgar scores were similarly good in both groups. CONCLUSION: Phenylephrine added to an infusion of ephedrine halved the incidence of hypotension and increased umbilical cord pH.

Adult↗

[Prevention of infections transmitted by CPAP and noninvasive ventilation].

Nosocomial infections are recognized as a major problem in patients with endotracheal ventilation, but the risk of nosocomial pneumonia is less well known and considered to be lower for patients on noninvasive ventilation. The risk factors for endotrachial ventilation involve the presence of the endoracheal canula and the direct consequences of the reclining position, use of a respirator, sedation, presence of a nosgastric tube, antiulcer treatment, etc. Most of these risk factors are not present in noninvasive ventilation while others, for example the use of a respirator and a ventilation circuit, persist. Several recent studies have demonstrated lower rates of infection in noninvasive compared with endotracheal ventilation. The notion of a specific risk of noninvasive ventilation-related nosocomial infection is less certain although current data do show a risk level no higher than in non-ventilated patients. Noninvasive ventilation should therefore be considered as a preventive measure against nosocomial infection whenever it can replace invasive ventilation. More or less specific preventive measures should however be employed. The principal actions involve taking advantage of the noninvasive nature of the ventilation to reduce the risk factors and other invasive procedures indirectly related with the use of artificial ventilation. Patients should be mobilized as rapidly as possible and oral food intake instituted early. Certain measures concerning humidification of the ventilation circuit remain important as well as other nonspecific measures including hand washing, for the prevention of cross contamination.

Procedural Sedation↗

Effect of CO(2) pneumoperitoneum on early cellular markers of retinal ischemia in rabbits with alpha-chymotrypsin-induced glaucoma.

BACKGROUND: Increased intraperitoneal pressure in the head-down position is associated with a significant increase in intraocular pressure (IOP) in rabbits with alpha-chymotrypsin-induced glaucoma. Also, the retinal cells are weakened by the induction of increased IOP, and/or glaucoma, even when IOP is controlled by adequate therapy; therefore, these cells need to be protected from any additional aggression. Actin and vimentin are proteins of the retinal cell cytoskeleton that react readily in response to retinal injuries, including ischemia and glaucoma. Early changes in these cytoskeleton proteins determine the morphological changes observed after retinal damage. Therefore, we set out to investigate intracytoplasmic changes in vimentin and actin after a 4-h CO(2) pneumoperitoneum in the head-down position in rabbits with alpha-chymotrypsin-induced glaucoma. METHODS: Twenty-one rabbits with alpha-chymotrypsin-induced glaucoma in one eye received general anesthesia for 4 h in the head-down position and were randomly allocated to have (a) no pneumoperitoneum, (b) a 10 mmHg CO(2) pneumoperitoneum, or (c) a 20 mmHg CO(2) pneumoperitoneum. At the end of the trial, both the right glaucomatous and the left control eyes were enucleated and investigated immunocytochemically for alterations in vimentin and actin, and morphologically for retinal layer disorganization. RESULTS: Except for the preexisting morphological changes induced by glaucoma, both the control and the glaucomatous eyes in all rabbits appeared normal in terms of retinal layer organization and the distribution of intracellular vimentin and actin whatever the intraperitoneal pressure level applied. CONCLUSION: In rabbits with alpha-chymotrypsin-induced glaucoma, a 4-h CO(2) pneumoperitoneum of </=20 mmHg in the head-down position did not induce either retinal layer disorganization or alteration of actin or vimentin.

Actins↗

[Auditing of drug use practices in anesthesia].

OBJECTIVES: Internal pharmaceutical practice guidelines were produced in a department of anaesthesia of a University hospital in 1995, after a preliminary evaluation showing controversial and expensive practices. After approval, these recommendations were circulated to all members of the department. Phase I of this study was started 18 months later, to evaluate the compliance of anaesthetists with these guidelines. STUDY DESIGN: Prospective survey. METHOD: An audit was performed by a research assistant pharmacist, previously trained, who compared anaesthetic agents and fresh gas flows used during anaesthetics with those recommended in the internal guidelines. RESULTS: Implementation of guidelines was observed in more than 90% of cases for all agents studied, except for non-depolarizing neuromuscular relaxants. Relaxants of intermediate duration were used in 52% of cases with an expected surgery duration of more than 90 min, in opposition to the guidelines stating that pancuronium should have been administered in such circumstances. These results were presented and discussed. Slight changes in the guidelines (especially concerning monitoring of neuromuscular blockade) were made and evaluated again, using the same method (Phase II). A small but significant improvement was seen with induction agents (use of propofol in non-approved situations: 5 versus 0%, P = 0.03), while a non significant trend toward better implementation of guidelines was seen with non-depolarizing agents (use of pancuronium in surgery of expected duration > 90 min: phase I vs phase II = 47 vs 52%, NS; use of pancuronium in surgery of expected duration < 90 min: phase I vs phase II = 3.5 vs 0%, NS). CONCLUSION: This study suggests that implementation of internal guidelines is easy when clinical indications of the agents are not controversial.

Anesthetics↗

[Impact of an information booklet on patient satisfaction in anesthesia].

OBJECTIVE: The aim of this study was to evaluate the satisfaction of adult surgical patients before and after an information booklet concerning anaesthetic techniques and complications, and postoperative management has been proposed during preanaesthetic visits. STUDY DESIGN: Survey. METHOD: Three surveys have been performed using an anonymous questionnaire of 25 items with graduated answers (very good, good, bad, very bad, no opinion) concerning patient satisfaction on structure, physician behavior, information and well being. As the results of the first two surveys were not significantly different, an information booklet was proposed to patients during preanaesthetic visits, then a third survey ("After") was realized. The results of this survey were compared to the combined results of the first two surveys ("Before"). RESULTS: In the "before" survey, 60 to 76% of the patients were satisfied (very good and good) of the information delivered during preanaesthetic visits. The proportion of patients satisfied of the information concerning anaesthetic techniques, transfusion and recovery were significantly higher in the "after" survey (P < 0.05). CONCLUSION: An information booklet on anaesthesia increases patient satisfaction on information provided during preanaesthetic visits.

Adult↗