Annales de l'anesthesiologie francaise最新文献

The aim of the present study was to validate the method for the measurement of total compliance proposed by Siemens Elema. The pressure and flow signals of the Servo 900 respirator are treated by an LMC-940 calculator. 1 - A study with a pulmonary model was used to evaluate the applicability of the measuring techniques used by the calculator. Tele-inspiratory alveolar pressure is accurately assessed for successive measurements of inspiratory resistance if the interruption of inspiratory flow is at least 0.3 seconds. Tele-expiratory alveolar pressure is accurately interpreted even if flow at the end of expiration is not nil, as long as airway resistance remains constant. The error in measurement of tidal volume depends in part upon the compression relaxation effect of gases in the circuit. The device used to compensate for this effect is effective up to a tele-inspiratory pressure of 1.96 kPa (20 cm H2O). Beyond this pressure, tidal volume is overestimated. The error is small, if the time after which the flow is integrated is 130 ms. For shorter periods, the correction is less satisfactory. 2 - A study in eight patients was used to assess the validity of 38 measurements of Ctot on the respirator in comparison with contemporary measurements made under static conditions using a syringe. A highly significant linear correlation was seen between values of Ctot obtained by the two methods: Ctot syringe = 0.94 X Ctot calculator = 0.55 ml.cmH2O-1. (n = 38; r = 0.95; p less than 0.001). The mean error of the calculator for a given reference value was 0.099 l.kPa-1 (9.65 ml.cmH2O-1). There was a closer relation for variations in Ctot recorded by the two methods. Variations were always in the same sense, and their correlation was highly significant (n = 19; r = 0.98; p less than 0.001). Such a method for the surveillance of compliance is extremely easy. The accuracy of absolute values for Ctot is limited but it is a reliable method for following variations in compliance and hence the effects of treatment.

This study was aimed at comparing pre- and immediately postoperative plasma amino acids levels in ten patients undergoing moderately important surgery and anaesthetised using the same protocol. Amino acid levels were measured using and automatic analyser equipped with an ion exchanger column. Changes in total blood amino acid levels showed wide variations. It is difficult to assess the role played by possible changes in blood volume, and for this reason results are expressed as a percentage of total amino acid levels. Under such conditions, findings were as follows: - taurine and alamine rose significantly; - there was a significant fall in serine, citrulline, alpha- amino-butyric acid and isoleucine. The results of this study differed markedly from findings reported in the literature: the authors noted a fall in plasma amino acid levels both in relation to preoperative levels as well as in relation to "normal" levels in the literature. This could be related to haemodilution, this hypothesis being supported by the fall in total aminogram in eight of the ten patients of the group. The most notable fact in the variations seen in this study was the rise in plasma alamine levels which could be indicative of a fall in gluconeogenesis. This hypothesis requires confirmation.

The authors report their experience of skin tests used to investigate cellular immunity in the detection of a high risk population pre-operatively. Over an 18 month period, 114 patients about to undergo major surgery were tested. The following three antigens were used: candinin, varidase and tuberculin. Results confirmed the prognostic value of these tests in terms of the overall prediction of complications (75 per cent in anergic individuals as against 24,4 per cent in reactors--p less than and deaths (45 per cent in anergics as against 8,5 per cent in reactors--p less than). Similarly, complications and deaths due to infection were more numerous in the anergic group (respectively 45 per cent and 25 per cent) than in the reactors (respectively 14,8 per cent and 4,2 per cent). Amongst factors which might influence the immune response, the authors studied successively the sex and age of the patients, pre-operative infection, neoplasia and undernutrition.

This article first looks at the pharmacokinetics of local anesthetic agents injected intravenously, and then looks at the possible practical applications of this technique: the choice of a local anesthetic agent as a function of its toxic side effects, the use of lidocaïne in local and regional intravenous anesthesia, and the treatment of cardiac rhythm disorders. Finally the article envisages the pharmacokinetics of local anesthetic agents used in local-regional anesthesia. This depends on the following factors: the site of injection, the dosage, the speed of injection, the possible addition of adrenalin and the nature of the local anesthetic itself. On the basis of a personal study the authors underline the difficulty of being precise in the pharmacokinetics of local anesthetic agents injected by the peridural route continuously or discontinuously.