Annales de l'anesthesiologie francaise最新文献

Blood prolactin levels (PRL) rise significantly in man following stress or the administration of many drugs. This finding led the authors to study variations in PRL during anaesthesia with Enflurane or Alfatesine. Repeated estimations of PRL were made in 38 subjects: in 8 cases (3 female and 5 male) under anaesthesia with Enflurane only, in 10 cases (6 female and 4 male) with Alfatesine only, in 10 cases (5 female and 5 male) with Enflurane and surgery and in 10 other cases (5 female and 5 male) with Alfatesine with surgery. No significant increase in PRL was seen during the administration of anaesthesia without surgery. By contrast, significant changes were seen when surgery was performed. No significant difference was seen in the results between the two sexes in each group. Taking into account the results of earlier experiments, the authors conclude that Enflurane or Alfatesine alone do not influence the hypothalamo-pituitary axis, but do not protect it during surgical and/or pharmacological stress.

The authors present a disposable device which may be used for skin tests studying delayed cellular hypersensitivity with 7 antigens and a glycerin control. With the aim of more objective evaluation of the results, they suggest the establishment of a score taking into account the number of positive reactions and the degree of the reactions. Finally, they describe the results of a large multicentre study involving 830 subjects considered to be healthy and divided into 4 groups according to the response to the tests.

Intrapulmonary occult bleeding is a serious complication of anticoagulants. Diagnostic difficulties are such that this complication is rarely described: 8 cases in the literature. The authors report two new cases. In both of these patients oral anticoagulant therapy resulted in a severe haemorrhagic syndrome on a clinical (melaena and/or epistaxis) and laboratory (haemoglobin less than 9 g/100 ml and prothrombin time less than 10 p. 100) basis. After a period of 24 to 48 hours, an acute respiratory distress syndrome developed. There was dyspnoea without major haemoptysis, a hypoxia/hypercapnia syndrome and, by X-ray, the rapid development of a diffuse micronodular miliary picture. The diagnosis of intrapulmonary occult bleeding was based upon fibroscopy with bronchoalveolar lavage (BAL) showing the pathological presence of large numbers of alveolar siderophages. However, the worsening of hypoxia brought about by bronchoalveolar lavage is such that careful consideration must be taken before the technique is used. Intrapulmonary occult bleeding must therefore be borne in mind in the presence of an imbalance in anticoagulant treatment complicated by respiratory distress and a reticulonodular radiological appearance.

A new automatic apparatus for the measurement of arterial pressure by a non-invasive technique was compared with direct intra-arterial measurement in 20 adult patients in a surgical intensive care unit. The apparatus works on the basis of the principle of oscillometry. Blood pressure is determined with a microprocessor by analysis of the amplitude of the oscillations produced by a cuff which is inflated then deflated automatically. Thus mean arterial pressure corresponds to the maximum amplitude. Systolic and diastolic pressures are deduced by extrapolation to zero of the amplitudes on either side of the maximum reading. Mean arterial pressure (AP) proved to be very reliable within the limits studied: 8.0 - 14.7 kPa (60 - 110 mmHg) with a difference in mean direct AP and indirect AP of 0,09 +/- 0.9 kPa SD (0.71 +/- 7 mmHg) and a coefficient of linear correlation between the two methods of r = 0.82. This non-invasive technique determined systolic arterial pressure (sAP) in a less reliable fashion than AP when compared with the invasive technique, with a tendency to flatten the extreme values. The correlation coefficient here was 0.68. Finally, diastolic arterial pressure (dAP) showed a better degree of agreement through with a difference in mean indirect AP and mean direct AP of 1.0 +/- 0.8 kPa (7.6 +/- 6.0 mmHg). These results indicate a good degree of agreement for measurements of mean arterial pressure, clinically the most important, between the two methods used. Measurements of diastolic pressure and above all of diastolic pressure seemed to be less in agreement. This difference could be due to an error in determination of the automatic apparatus tested or to the peripheral site (radial artery) of the intra-arterial catheter used, itself falsifying the humeral arterial pressure.

The authors studied early changes in immune state by the nuclear refringence test in 12 patients undergoing gynaecological surgery for non-malignant conditions. The test was performed before and thirty minutes after the induction of anaesthesia. Twenty five per cent of the patients showed abnormalities of the nuclear refringence test in the presence of Con A2. The interpretation of the results and the predictive value of the test are discussed.

Even though the anesthetic agents thiopental, ketamine, propanidid and etomidate all belong to very different chemical families they are all characterized by a very large degree of liposolubility. This explains their rapid penetration into the brain. The pharmacokinetic model of thiopental is a three compartment model. There is strong protein binding and only the free fraction is active. The very short action of the product after a single injection is due to the rapid redistribution of the agent into the muscle mass because its hepatic metabolization is very slow. However, when given over prolonged time the adipose compartment plays an important role in the mixture of the product, explaining the prolonged sleep produced. The central depressant actions of thiopental and consequently its action on CMRO2 depend on the initial dose and the route of administration. A single and massive injection produces a small and temporary reduction in the CMRO2 even though the plasmic concentration is high. In contrast prolonged intravenous infusion produces more severe and longer lasting depression of the CMRO2. The pharmacokinetic model of ketamine is tri-compartmental. There is weak protein binding. After IV injection ketamine rapidly enters the brain and the maximum concentration is reached one minute later. After that the cerebral concentration rapidly falls as does the plasma level. Signs of waking are seen at a concentration of 130 micrograms per gram of tissue. An increase in the dose of ketamine does not much influence the duration of analgesia but increase the waking time. This suggests that its indication in ambulatory anesthesia should be looked at with care. It is metabolized by the liver with the formation of several metabolites of which some are active. The kinetics of propanidid can be explained on the basis of a monocompartmental model. The speed of the fall in plasma level of the product is related to the speed of injection. High plasma concentrations mobilize a larger quantity of plasma pseudo-cholinesterases, increasing thus the speed of degradation. The product is rapidly hydrolized (plasma and liver cholinesterases). The duration of action is longer when used at low doses or when it is administered at a constant dose. Propanidid does not have any accumulative effect. The kinetics of etomidate follow a tri-compartmental model. It is very rapidly and largely distributed in the organism, the peak cerebral concentration being reached in less than one minute. There is strong protein binding. Repeated administration of the drug produces an increase in anesthetic sleep but also a delay in recovery. Etomidate is hydrolized by hepatic esterases.

This method can assay simultaneously, using 300 microliters of plasma, of the three principle local anesthetic agents used by peridural injection for post-operative anesthesia and analgesia: xylocaïne, etidocaïne, bupivacaïne. The assay method consists of three steps: (a) the addition of an internal calibrating agent (mepivacaïne). (b) defecation using trichlorocetic acid. (c) alcalinization of the supernatent (pH 11), extraction with dichloromethane and concentration at room temperature of the organic phase. (d) chromotography using an SE 30 or OV 17 impregnated column. The method is sensitive between 0.37 mumoles per l-1 (0.1 microgram . ml-1) and the coefficient for the mean deviation is 10.9% for concentration between 0.37 mumoles 1-1 and 75 mumole1-1 (0.1 microgram . ml-1 and 20 micrograms . ml-1). The correspondence of the figures recorded in this large concentration range without any change in the technique means that the kinetics of the plasma concentrations before and after peridural injection can be followed. The results obtained by gas liquid chromatography for the assay of lidocaïne were compared in 115 different plasma samples with concentrations obtained by an immuno enzymatic method ("EMIT") fitted to a centrifuge analyser. The correlation coefficient between the two methods was: (r = 0.95 with y = 0.09 x +0.25 microgram . ml-1 implying the absence of any interference and the specificity of the two methods. The columns also separate in 20 minutes the two main metabolites of lidocaïne: monoethylglycinexylidide (M.E.G.X.) and glycinexylidide (G.X.). These results demonstrate that continuous peridural injection of lidocaïne produces a high plasma concentration without any clinical toxic phenomena.