Canadian journal of anaesthesia = Journal canadien d'anesthésie
-
Comparative Study
Arterial to end-tidal carbon dioxide tension difference during anaesthesia in early pregnancy.
Sixteen patients requiring general anaesthesia for termination of pregnancy by dilatation and evacuation of the uterus were studied. Arterial and end-tidal carbon dioxide tensions were determined during anaesthesia. ⋯ These results were similar to those observed during Caesarean section and those during anaesthesia for post-delivery tubal ligations. The physiological changes such as increased cardiac output, haemodilution, and increased blood volume which manifest by 12 weeks of gestation probably result in a reduced (a-E')PCO2 value.
-
Administration of epidural and intrathecal opioids may provide excellent postoperative analgesia, but a minority of patients will suffer dangerous respiratory depression. This review discusses the detection and measurement of respiratory depression and summarizes the relevant literature as it pertains to epidural and intrathecal opioid administration. The respiratory depressant effects and pharmacokinetics of spinal opioids are reviewed. The clinical implications and areas of future investigation are discussed.
-
Comparative Study
Nitrous oxide does not increase nausea and vomiting following gynaecological laparoscopy.
The effect of three different anaesthetic techniques on the incidence and severity of postoperative emesis (nausea, retching and vomiting) was studied in 150 patients undergoing gynaecological laparoscopy. Patients were anaesthetized with isoflurane in nitrous oxide and oxygen (Group A), enflurane in nitrous oxide and oxygen (Group B) or with isoflurane in air and oxygen (Group C). ⋯ The overall incidence of emesis during the first 24 hours postoperatively was 54, 48 and 52 per cent, in groups A, B and C, respectively. It is concluded that nitrous oxide does not increase the incidence of emesis after isoflurane anaesthesia and that isoflurane and enflurane anaesthesia are associated with similar incidences of nausea and vomiting after gynaecological laparoscopy.
-
Previous studies have reported haemodynamic interactions between dihydropyridine calcium antagonists and general anaesthesia. During anaesthesia for intracranial aneurysm surgery, we prospectively compared haemodynamic values obtained from 13 patients being treated with nicardipine HCl (0.15 mg.kg-1.hr-1 IV) for cerebral vasospasm against values obtained from 11 untreated controls. Prior to induction of anaesthesia, nicardipine-treated patients had significantly elevated mean +/- SD cardiac index (5.67 +/- 1.30 vs 3.99 +/- 0.73 L.min-1.m-2) while MAP (86 +/- 10 vs 99 +/- 14 mmHg) and systemic vascular resistance (647 +/- 227 vs 1141 +/- 404 dynes.sec-1.cm-5) were reduced. ⋯ Mannitol infusion and deliberate hypotension resulted in nearly identical haemodynamic responses in both groups. Nicardipine-treated patients required more intravenous fluids during the operative procedure (2.4 +/- 0.3 L vs 1.5 +/- 0.4 L, P less than 0.05) and were less likely to require isoflurane supplementation to morphine sulphate/nitrous oxide anaesthesia (P less than 0.01). In summary, our experience with nicardipine HCl revealed no major untoward effects with respect to maintenance of intraoperative haemodynamic stability despite continuous antivasospasm therapy with this vasodilator.
-
Twenty-seven anaesthesia faculty, fellows and residents compared a standard intubating mannequin and an anaesthetized pig as models for teaching fibreoptic tracheal intubation. When likened to the clinical situation, the anatomic characteristics of the pig airway were rated as significantly more realistic than the airway characteristics of the mannequin with the exception of the appearance of the epiglottis. In addition, the overall score for the pig model was significantly higher than the score for the mannequin and 26 of 27 evaluators rated the anaesthetized pig as the more effective teaching model. We conclude that an anaesthetized, spontaneously breathing pig is a valid model for teaching fibreoptic endotracheal intubation.