A single i.v. dose of ondansetron 8 mg prior to induction of anaesthesia reduces postoperative nausea and vomiting in gynaecological patients.

The effect of a single intravenous dose of ondansetron in preventing postoperative nausea and emesis (retching and vomiting) (PONV) was investigated in a randomized, double-blind, placebo-controlled, multicentre, international study. Women of ASA class I-III, requiring gynaecological laparotomy, vaginal hysterectomy, or major vaginal surgery were selected for study. Two hundred and thirty-five received placebo, 231 received 1 mg ondansetron, 228 received 8 mg ondansetron and 229 received 16 mg ondansetron, as an infusion over five minutes before the induction of anaesthesia. A standardized balanced anaesthetic technique was employed. This consisted of premedication with either diazepam or temazepam, thiopentone induction, maintenance with nitrous oxide in oxygen supplemented with enflurane or isoflurane, intraoperative analgesia with fentanyl, neuromuscular blockade with any choice of agent and reversal with neostigmine and atropine. Postoperative analgesia was achieved with morphine, and prochlorperazine or metoclopramide were given if a rescue antiemetic was required. A greater percentage of patients in the 8 mg and 16 mg ondansetron groups experienced no postoperative emesis (44% and 39% respectively) than in the placebo and 1 mg ondansetron groups (29% and 28% respectively) for the first 24 hr postoperative period (8 mg vs placebo and 1 mg: P < or = 0.001; 16 mg vs placebo: P < 0.05; 16 mg vs 1 mg: P < 0.05). Similarly, the percentage of patients who did not experience postoperative nausea were 20%, 26%, 31% and 28% for the placebo, 1 mg, 8 mg and 16 mg ondansetron treatment groups, respectively (8 mg and 16 mg vs placebo P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative value of clinical signs of difficult tracheal intubation in women]. / Valeur comparée des signes cliniques d'intubation difficile chez la femme.

A prospective study was designed to compare the value of clinical signs aimed to predict difficult intubation in women. A group of 663 women, scheduled for elective surgery, were assessed by an anaesthetist at the preanaesthetic visit. Following parameters were assessed: the degree of mouth opening, the chin-hyoid bone and the chin-thyroid cartilage distances, dental and facial abnormalities, age, weight. All patients were ranked on the Mallampati scale. Another anaesthetist carried out the anaesthetic induction and endotracheal intubation. The latter was deemed to have been difficult if special procedures had been required (use of a stylet, a fibroscope, or Sellick's manoeuvre). In accordance with these criteria 12.5% of women were difficult to intubate. Furthermore, he assessed the degree of glottic exposure, using a Macintosh blade and according to Cormack's classification. Six per cent of women were ranked C or D in Cormack's classification (C: the glottic aperture was not seen; D: the epiglottis was not seen). Finally 66% of women with difficult intubation and 84% of those with severely abnormal glottic exposure were ranked greater than 1 on the Mallampati scale. This scale had high sensitivity (0.84), but a specificity of only 0.66. Other clinical criteria (mouth opening, the chin-hyoid bone distance) had a lower sensitivities, but seemed more specific. Multivariate analysis showed that specificity could be improved (0.84) if the distance between the upper and lower incisor teeth (mouth opening) was associated with Mallampati's rank, without any loss in sensitivity. A simple chart is proposed to assess the risk of difficult intubation.

[Retrograde orotracheal intubation]. / L'intubation oro-trachéale par voie rétrograde.

Four different techniques of retrograde tracheal intubation were studied in 77 cadavers (patients who had died less than 4 h before). None had any laryngeal disease or a previous intubation. Following techniques were evaluated: cricothyroid membrane puncture; infracricoid puncture; catheter guide inserted through the endotracheal tube; catheter guide only inserted through the distal lateral eye (Murphy eye) of the endotracheal tube. An epidural catheter was used as a guide. Success rate was low (5 out of 17 attempts) when cricothyroid puncture was used, and the guide passed through the whole length of the tube. All 20 attempts were successful when infracricoid puncture was used and the guide passed through the distal lateral eye of the endotracheal tube. The different techniques and equipment needed are discussed in the light of the available literature. Retrograde tracheal intubation seems to be an easy and useful technique, which all anaesthetists should know, in case of difficult intubation.

Thrombogenicity of central venous catheters: prospective study of polyethylene, silicone and polyurethane catheters with phlebography or post-mortem examination.

The thrombogenicity of polyethylene, silicone and polyurethane central venous catheters was compared in a prospective clinical, phlebographic and post-mortem study in 52 patients. The incidence of central venous thrombosis was high with polyethylene catheters (70%), but much lower with silicone (20%) and with polyurethane catheters (17%).