Annales françaises d'anesthèsie et de rèanimation
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Ann Fr Anesth Reanim · Jan 1993
ReviewMechanisms of activation of human mast cells and basophils by general anesthetic drugs.
A study was performed about the effects of increasing concentrations of muscle relaxants (suxamethonium, d-tubocurarine, vecuronium, and atracurium), hypnotics (propofol, ketamine, and thiopental), opioids (morphine, buprenorphine, and fentanyl), and benzodiazepines (diazepam, flunitrazepam, and midazolam) on the release of preformed (histamine and tryptase) and de novo synthesized (prostaglandin D2: PGD2 and peptide-leukotriene C4: LTC4) chemical mediators from human basophils and mast cells isolated from skin (HSMC), lung parenchyma (HLMC) and heart tissue (HHMC). None of the drugs tested induced the release of histamine or LTC4 from basophils of normal donors. Suxamethonium did not induce mediator release from any type of human mast cell tested. ⋯ Diazepam and flunitrazepam only induced a small release of histamine from mast cells, whereas midazolam caused the release of histamine from HLMC. The biochemical pathways underlying the release of mediators from human mast cells induced by drugs used during general anaesthesia are different from those underlying the immune release of histamine. From the results obtained with the in vitro model described here, it is clear that new drugs promising for the anesthesiologic arena should be tested in vitro before their potential histamine-releasing activity is experienced in vivo.
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Ann Fr Anesth Reanim · Jan 1993
Review[Continuous monitoring of mixed venous blood oxygen saturation].
Mixed venous oxygen saturation (SvO2), measured on pulmonary artery blood, is a convenient indicator of matching between O2 transport (TaO2) and O2 body consumption (VO2). The measurement technique is based on the haemoglobin reflection spectrophotometry principle using two or three wave lengths. The Fick principle points out that SvO2 depends on five parameters: SvO2 = SaO2 - (VO2/CI x Hb x PO) where SaO2, CI and PO respectively represent arterial O2 saturation, cardiac index and O2 affinity. ⋯ Finally, the existence of a right-to-left shunt will modify the SvO2 values through various mechanisms. However the SvO2 measured, in the pulmonary artery, remains reliable, whereas the presence of a left-to-right shunt will highly alter SvO2 basal value, only its time course remaining significant. SvO2 monitoring, element of diagnosis and monitoring, as well as a warning signal, has a priori specific indications poorly assessed, so far. (ABSTRACT TRUNCATED AT 400 WORDS)
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Ann Fr Anesth Reanim · Jan 1993
Review[Anesthesia for non-specific surgery in a post-transplantation patient].
The increase of non specific surgeries in transplanted patients may be related to the better survival achieved by the efficacy of immunosuppressive therapy and improved surgical and intensive care conditions. Therefore, the anaesthetist may be mandated to give anaesthesia in such patients, treated in hospitals which are not involved in transplantation procedures. The ignorance of the main physiologic and pharmacological changes in the new grafted organ as well as the knowledge of high risks of rejection or infection contribute to the anxiety often encountered in front of these patients. ⋯ Ciclosporine enhances mainly the effects of muscle relaxants. Peroperative invasive monitoring requires full aseptic techniques. Invasive monitoring should be discussed in terms of benefit-risk ratio.(ABSTRACT TRUNCATED AT 400 WORDS)
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Ann Fr Anesth Reanim · Jan 1993
Review Case Reports[Intraosseous infusions in pediatric life-threatening emergencies].
As the bone marrow is a vascular tissue which cannot collapse, it may be used as a vascular access to treat life-threatening emergencies especially in children. Two cases reported here underline the value of this life-saving procedure. Both children were 9 months old, and were admitted for severe dehydration, having lost 15 and 10% of body weight respectively. ⋯ The intraosseous line was replaced, in the first child, at the third hour, by a conventional infusion line, set up by denudation, and in the second one, by a subclavian line. This technique has few contra-indications, and the complication rate is low. However, this technique should remain limited to a few indications only.
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Cervical epidural anaesthesia (CEA) results in an effective sensory blockade of the superficial cervical (C1/C4) and brachial plexus (C5/T1-T2). It is used both intraoperatively and in the treatment of postoperative or chronic pain. The approach to the epidural space at the C7-T1 interspace is not technically difficult. ⋯ It is also for shoulder and upper limb surgery as well as for pharyngolaryngeal surgery, providing efficient operative anaesthesia and postoperative analgesia. CEA is used for relief of chronic pain in the head and neck or cancer pain due to Pancoast-Tobias syndrome. It seems to be effective for treating pain in patients with unstable angina pectoris or acute myocardial infarction.