Annales françaises d'anesthèsie et de rèanimation
-
Ann Fr Anesth Reanim · Jan 1994
[Dysfunction of vaporizers and nitrous oxide: solubility or viscosity?].
Sudden switch of carrier gas from O2 to the N2O/O2 mixture results in an acute decrease in vapour output for a variable delay of time. This has been attributed to the dissolution of N2O in the volatile anaesthetic liquid. The final vapour concentration at steady state had been previously reported to be lower than the concentration dial setting: this was attributed to vaporizer design and to viscosity of carrier gas. ⋯ To test the solubility hypothesis, the same enflurane Dräger Vapor 19 vaporizer was emptied, dried, saturated with enflurane, emptied and then filled with either 10 or 100 mL of liquid enflurane. To test the viscosity hypothesis, a model of a vaporizer was devised, in which the gas movements are described with the Poiseuille's law. In this model, the delivered concentration F depends on the vapour pressure, the input pressure of the gas flow, the viscosity of the carrier gas and the viscosity of the agent saturated gas.(ABSTRACT TRUNCATED AT 250 WORDS)
-
The laryngeal mask ensures a better control of the airway than the face mask, without the disadvantages of an endotracheal tube. Moreover, it provides an effective and simple solution to many problems of difficult intubation and therefore it has a place amongst the equipment required for difficult intubations. The laryngeal mask will most probably become more widely used, provided that its contra-indications are taken into account. ⋯ Many studies have shown that propofol is suitable for use with the laryngeal mask. However, it should be noted, that there is, as yet, no conclusive evidence of the superiority of propofol over other induction agents. In anaesthesia for day-case surgery, the combination of the laryngeal mask and propofol could prove beneficial.
-
Ann Fr Anesth Reanim · Jan 1994
[Intestinal mucosa injury during experimental endotoxin-induced shock].
To ascertain tissue oxygenation during conversion from hypo to hyperdynamic state with vascular volume expansion, venous outflow from a segment of ileum was isolated in anesthetized and pump-ventilated endotoxic dogs to measure gut oxygen uptake (VO2), lactate metabolism, intramucosal PCO2 and tissue PO2 (PtiO2). Tissue PO2 was measured by multipoint surface Mehrdraht Dortmund Oberfläche electrodes placed on mucosal and serosal surfaces of gut. Six dogs were infused with 2 mg.kg-1 E. coli lipopolysaccharide (LPS) in one hour followed by a two hour 0.5 mL.kg-1.min-1 dextran infusion. ⋯ In the gut, VO2 remained low and intramucosal PCO2 as well as lactate output remained high, despite increased flow. Gut PtiO2 results suggested blood flow maldistribution with tissue hypoxia in the mucosa despite increased total flow to the gut. Gut VO2, lactate flux, intramucosal PCO2, and tissue PO2 were consistent with regulatory responses that shut down mucosal perfusion and oxygenation in spite of increased blood flow to gut.
-
Total intravenous anaesthesia using propofol is indicated in the following cases: patients with a previous history of postoperative nausea or vomiting; surgery of the middle ear; gynaecological procedures involving laparotomy; ENT and squint surgery in children. Up to now, the relationship between the clinical benefit (less incidence of postoperative nausea and vomiting) and intrinsec anti-emetic properties of propofol is not included in the regulatory labelling.
-
Ann Fr Anesth Reanim · Jan 1994
[Infectious complications linked to the use of Diprivan. Precaution of administration].
In order to avoid the risk of severe infection by bacterial contamination of propofol, all users of this agent, should be reminded of the required aseptic technique "for the correct use of Diprivan". These points have recently been listed by Zeneca Pharma. They mainly include the following items: 1. ⋯ Disinfection of the ampoule neck or vial stopper using and antiseptic solution before opening, is a strongly measure recommended. 5. Finally, hand washing should be routine, prior to these manipulations. As far as the above mentioned precautions are strictly followed, this anaesthetic agent may be used safely, even in case of prolonged sedation.