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Biomedical subjects

Marie-Claire Laxenaire

Publications and source records attributed to Marie-Claire Laxenaire.

8 recordsLinked to original sources
PubMed2005

Anaphylactic shock: a form of distributive shock without inhibition of oxygen consumption.

BACKGROUND: The pathophysiology of anaphylactic shock during anesthesia is incompletely characterized. It is described as distributive by analogy with septic shock (anaerobic metabolism, high tissue oxygen pressure [Ptio2] values). The Ptio2 profile and its metabolic consequences during anaphylaxis are not known. METHODS: Ovalbumin-sensitized anaphylactic shock rats (n = 11) were compared to nicardipine-induced hypotension rats (n = 12) for systemic hemodynamics, Ptio2, sympathetic nervous system activation, skeletal muscle blood flow, and interstitial lactate and pyruvate concentrations using combined microdialysis and polarographic Clark-type oxygen probes. RESULTS: In both groups, the time course and the magnitude of arterial hypotension were similar. The ovalbumin group but not the nicardipine group displayed decreased skeletal muscle blood flow (from 45 +/- 6.2 ml x 100 g(-1) x min(-1) to 24.3 +/- 5 ml x 100 g(-1) x min(-1); P < 0.0001) and Ptio2 values (from 42 +/- 5 to 5 +/- 2; P < 0.0001). The ovalbumin group had more intense sympathetic nervous system activation with higher plasma epinephrine and interstitial norepinephrine concentrations. For the ovalbumin group, there was skeletal muscle anaerobic metabolism (lactate concentration increased from 0.446 +/- 0.105 to 1.741 +/- 0.459 mm; P < 0.05) and substrate depletion (pyruvate concentration decreased from 0.034 +/- 0.01 mm to 0.006 +/- 0.002 mm; P < 0.05) leading to increased interstitial lactate/pyruvate ratios (from 17 +/- 6 to 311 +/- 115; P < 0.05). CONCLUSIONS: This profile suggests decreased skeletal muscle blood flow and oxygen delivery. Persistent energy consumption results in decreased Ptio2 and substrate depletion through anaerobic glycolysis leading to complete failure of cellular energy production. This could explain rapid organ dysfunction and resuscitation difficulties.

Anaphylaxis↗
PubMed2003

A French survey of paediatric airway management use in tonsillectomy and appendicectomy.

BACKGROUND: There are no epidemiological data describing tracheal intubation and laryngeal mask airway (LMATM) use in paediatric anaesthesia. This analysis focused on the factors leading to the indication for an airway management procedure, i.e. tracheal intubation and laryngeal mask airway vs face mask during general anaesthesia for tonsillectomy and appendicectomy. METHODS: The data were recorded in the French survey of Practical Anaesthesia performed in 1996. Two main types of surgical procedures were selected: tonsillectomy and appendicectomy because of the number of patients and the need to use an invasive airway management technique. RESULTS: During a 1-year period, 627 anaesthetics for appendicectomy and 653 anaesthetics for tonsillectomy were recorded in the sample under consideration. Tracheal intubation or laryngeal mask airway was undertaken in 66% of tonsillectomies and 84% of appendicectomies. Univariate analysis showed that tracheal intubation/laryngeal mask were used significantly more often in older children, with long duration of anaesthesia, in nonambulatory procedures and in procedures performed at an academic centre. When these variables were included in a multivariate analysis, the duration of anaesthesia over 30 min was a factor linked to the use of tracheal intubation/laryngeal mask airway for the two types of surgery (P < 0.0001). For tonsillectomy, inpatients were 2.9 times more likely to be intubated (or have an laryngeal mask airway) than were outpatients. For appendicectomy, older children were 3.4 times more likely to be intubated (or have an laryngeal mask airway) than younger children. CONCLUSIONS: This large French survey shows that the use of tracheal intubation/laryngeal mask airway in this country is primarily related to a predicted long duration of anaesthesia.

Adolescent↗
PubMed2003

Anaphylactic and anaphylactoid reactions occurring during anesthesia in France in 1999-2000.

BACKGROUND: Anaphylactic and anaphylactoid reactions occurring during anesthesia remain a major cause of concern for anesthesiologists. The authors report the results of a 2-yr survey of such reactions observed during anesthesia in France. METHODS: Between January 1, 1999, and December 31, 2000, 789 patients who experienced immune-mediated (anaphylaxis) or nonimmune-mediated (anaphylactoid) reactions were referred to one of the 40 participating centers. Anaphylaxis was diagnosed on the basis of clinical history, skin tests, and/or specific immunoglobulin E assay. RESULTS: Anaphylactic and anaphylactoid reactions were diagnosed in 518 cases (66%) and 271 cases (34%), respectively. The most common causes of anaphylaxis were neuromuscular blocking agents (NMBAs) (n = 306, 58.2%), latex (n = 88, 16.7%), and antibiotics (n = 79, 15.1%). Rocuronium (n = 132, 43.1%) and succinylcholine (n = 69, 22.6%) were the most frequently incriminated NMBAs. Cross-reactivity between NMBAs was observed in 75.1% of cases of anaphylaxis to an NMBA. No difference was observed between anaphylactoid and anaphylactic reactions when the incidences of atopy, asthma, or drug intolerance were compared. However, atopy, asthma, and food allergy were significantly more frequent in the case of latex allergy when compared with NMBA allergy. Clinical manifestations were more severe in anaphylaxis. The positive predictive value of tryptase for the diagnosis of anaphylaxis was 92.6%; the negative predictive value was 54.3%. The diagnostic value of specific NMBA immunoglobulin E assays was confirmed. CONCLUSIONS: These results further corroborate the need for systematic screening in the case of anaphylactoid reaction during anesthesia and for the constitution of allergoanesthesia centers to provide expert advice to anesthesiologists and allergists.

Adult↗
PubMed2002

Evolution of the anaesthetic workload--the French experience.

The use of anaesthesia has shown major growth during the period 1975-1985. Increases safety in anaesthesia safety have permitted its use in surgery and in other exploratory procedures involving older patients and those with more severe clinical conditions. A survey, designed by the French Society of Anaesthesiologists, collected and analysed data relating to anaesthesia performed in France in 1996 from a representative sample collected in all French hospitals and clinics; the results of this survey were compared with an earlier survey performed in 1980. The participation rate of hospitals was 98%. The results of this survey showed that, between 1980 and 1996, the number of anaesthetic procedures had increased by 120% and the annual rate had increased from 6.6 to 13.5 anaesthetic procedures per 100 population. The annual rate varied between 5.4 per 100 in girls 5-14 years of age and 30.2 per 100 in men 75-84 years of age. The second important phenomenon which occurred between 1980 and 1996 was a marked increase in regional anaesthesia--from 4 to 23% of all cases. This represents a 14-fold increase in the number of cases involving regional anaesthesia. Anaesthesia for obstetric procedures represented 9% of all cases. Seventy-six per cent of all anaesthetics which were started between midnight and 7.00 a.m. were related to obstetric activities. Changes that occurred in the practice of anaesthesia could be explained by changes in the types of procedure requiring anaesthesia: in 1980, 88% of anaesthetics were required for surgical procedures, while in 1996 surgery accounted for 71% of all cases, obstetrics for 9%, and other procedures for the remaining 20%. The practice of epidural anaesthesia for deliveries has developed markedly in France during recent years, increasing from 1.5 to 51% of all deliveries between 1980 and 1996. This survey has offered an interesting overview of recent developments in anaesthesia--which are probably representative of the evolutionary trends in most industrialized countries. These changes can be summarized in three major points: (i) a global increase in the use of anaesthesia related to improvements in its safety; (ii) a significantly increased use of anaesthesia in elderly patients; and (iii) a marked increase in regional anaesthesia.

Adolescent↗
PubMed2002

Colostrum morphine concentrations during postcesarean intravenous patient-controlled analgesia.

UNLABELLED: Patient-controlled analgesia (PCA) with morphine is a convenient method for providing postoperative analgesia. Despite the fact that it is used after cesarean delivery, data on transfer of morphine and of its active metabolite morphine-6 glucuronide (M6G) into maternal milk are scarce. It is not known whether breast-feeding during PCA with morphine has neonatal implications. We sought to measure morphine and M6G concentrations in colostrum during postpartum IV PCA and evaluate the potential for drug intake by neonates being breast-fed by these mothers. Seven informed and consenting mothers, given IV PCA with morphine, were investigated. Plasma and milk samples were obtained at titration, and at 12, 24, 36, and 48 h. Morphine and M6G were measured by high-performance liquid chromatography. In plasma, morphine concentrations ranged from <1 to 274 ng/mL, M6G ranged from <5 to 974 ng/mL. In milk, opioids were found in only 3 patients in whom morphine concentrations ranged from <1 to 48 ng/mL and M6G from <5 to 1084 ng/mL. The milk-to-plasma ratio was always <1 for morphine. In conclusion, we observed very small morphine and M6G concentrations in colostrum during PCA with morphine. Under these conditions, the amounts of drug likely to be transferred to the breast-fed neonate are negligible. IMPLICATIONS: Colostrum concentrations of morphine and its active metabolite morphine-6 glucuronide were measured in mothers receiving patient-controlled analgesia with morphine after cesarean delivery. The concentrations were found to be very small, thus supporting the safety of breast-feeding in mothers receiving IV patient-controlled analgesia with morphine.

Analgesia, Patient-Controlled↗
PubMed2002

An evaluation of the cutaneous distribution after obturator nerve block.

UNLABELLED: In 1973, Winnie et al. introduced the inguinal paravascular three-in-one block, which allegedly provides anesthesia of three nerves--the femoral, lateral cutaneous femoral, and obturator nerves--with a single injection. This concept was undisputed until the success of the obturator nerve block was reassessed by using evidence of adductor weakness rather than cutaneous sensory blockade, the latter being variable in its distribution and often absent. We performed this study, therefore, to evaluate the area of sensory loss produced by direct injection of local anesthetic around the obturator nerve. A selective obturator nerve block with 7 mL of 0.75% ropivacaine was performed in 30 patients scheduled for knee surgery. Sensory deficit and adductor strength were evaluated for 30 min by using sensory tests (cold and light-touch perception) and the pressure generated by the patient's squeezing a blood pressure cuff placed between the knees. Subsequently, a three-in-one block was performed, and the sensory deficit was reassessed. The obturator nerve block was successful in 100% of cases. The strength of adductors decreased by 77% +/- 17% (mean +/- SD). In 17 patients (57%), there was no cutaneous contribution of the obturator nerve. The remaining 7 patients (23%) had an area of hypoesthesia (cold sensation was blunt but still present) on the superior part of the popliteal fossa, and the other 6 (20%) had sensory deficit located at the medial aspect of the thigh. The three-in-one block resulted in blockade of the lateral aspect of the thigh in 87% of cases, whereas the anteromedial aspect was always anesthetized. By use of magnetic resonance imaging in eight volunteers, we demonstrated that the obturator nerve has already divided into its two branches at the site of local anesthetic injection. However, the injection of blue dye after having simulated the technique in five cadavers showed that the fluid regularly spread to both branches. We conclude that after three-in-one block, a femoral nerve block may have been assessed as an obturator nerve block in 100% of cases when testing the cutaneous distribution of the obturator nerve on the medial aspect of the thigh. IMPLICATIONS: Previous studies reporting an incidence of obturator nerve block after three-in-one block may have mistaken a femoral nerve block for an obturator nerve block in 100% of cases when the cutaneous distribution of the obturator nerve was assessed on the medial aspect of the thigh. The only way to effectively evaluate obturator nerve function is to assess adductor strength.

Amides↗