Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Clinical Trial
Nifedipine attenuates the hypertensive response to tracheal intubation in pregnancy-induced hypertension.
Thirty women with pregnancy-induced hypertension (PIH) scheduled for Caesarean section under general anaesthesia were studied to evaluate the efficacy of sublingual nifedipine in attenuating the pressor response to laryngoscopy and tracheal intubation. The patients were randomly given either the contents of a nifedipine capsule 10 mg or placebo sublingually 20 min before induction of anaesthesia. Blood pressure and heart rate were recorded at various time intervals. ⋯ Heart rate increased in both the groups during the laryngoscopy and tracheal intubation (P < 0.01) but the increase was higher in the nifedipine group than in the control group (P < 0.05). Neonatal Apgar scores in both the groups were comparable. These results suggest that sublingual nifedipine is effective in attenuating the hypertensive response to laryngoscopy and intubation but not the tachycardiac response in parturients with PIH.
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The aim of this study was to devise and validate a technique to deliver constant air-oxygen mixtures from a standard anaesthetic machine using only oxygen as the compressed gas source. The common gas outlet was modified to allow measured quantities of ambient air to be insufflated via a three-way attachment into a closed circle absorber system with a double-circuit collapsible bellows ventilator. During positive pressure ventilation, leakages of between 50-150 ml.min-1 occur from the circuit and nomograms of the minimal air and oxygen flow rates needed to maintain constant oxygen concentrations in the presence of the leaks were then mathematically derived. ⋯ Next, the technique was studied on 18 patients who underwent isoflurane or propofol anaesthesia (duration 40-210 min) for various surgical procedures. Pooled mean values (SD) obtained were 29.3% (1.86), 40.95% (1.65) and 50.06% (1.41) respectively for predicted oxygen concentrations of 30, 40 and 50% respectively. We conclude that this technique can be used to deliver constant air-oxygen mixtures accurately during inhalational or total intravenous anaesthesia when N2O is contraindicated but a source of compressed air is not readily available.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of epidural tramadol and epidural morphine for postoperative analgesia.
The present study compared epidural tramadol with epidural morphine for postoperative analgesia in 20 patients undergoing major abdominal surgery. Intraoperatively, the patients were anaesthetized by a balanced technique of general anaesthesia combined with lumbar epidural lidocaine. In ten of the patients 100 mg tramadol diluted in 10 ml normal saline was also injected epidurally, while 4 mg epidural morphine was used in the other ten patients. ⋯ This was not associated with any increase in PaCO2 or a decrease of respiratory rate, suggesting that hypoxaemia rather than hypercarbia or decreased respiratory rate may be an earlier indicator of respiratory rate, suggesting that hypoxaemia rather than hypercarbia or decreased respiratory rate may be an earlier indicator of respiratory depression in patients breathing room air without oxygen supplementation. The absence of clinically relevant respiratory depression following epidural tramadol compared with epidural morphine may be attributed to the different mechanisms of their analgesic action. The results suggest that epidural tramadol can be used to provide prolonged postoperative analgesia without serious side effects.
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Randomized Controlled Trial Clinical Trial
Epidural anaesthesia and analgesia do not affect energy expenditure after major abdominal surgery.
Our objective was to determine the effect of perioperative epidural anaesthesia and analgesia on the increase in energy expenditure which accompanies major elective abdominal surgery in a prospective, randomized study. Eight patients undergoing elective resections of the colon and/or rectum received general anaesthesia alone (nitrous oxide, oxygen, and isoflurane, supplemented with intravenous fentanyl to a maximum of 10 micrograms.kg-1), and 12 patients received perioperative epidural anaesthesia and analgesia using lidocaine (carbonated lidocaine 2% with epinephrine 1:200,000, 20 ml over 30 min) and morphine (preservative-free morphine 0.10 mg.kg-1 after catheter insertion and 0.05 to 0.10 mg.kg-1 every 12 hr as needed until the morning following surgery) via a lower lumbar catheter in addition to general anaesthesia. ⋯ Oxygen consumption, carbon dioxide production, and energy expenditure increased after surgery (all P < 0.001) but were very similar in the two groups (all P > or = 0.8) before and after surgery. Despite substantial effects on postoperative pain, we conclude that oxygen consumption and energy expenditure following major abdominal surgery are not diminished by perioperative epidural anaesthesia and analgesia.
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We report a case of spinal subdural haematoma with neurological deficit in a 36-yr-old woman following Caesarean section for severe preeclampsia and placental abruption. She had been taking chronic trifluoperazine treatment for depression. Her activated partial thromboplastin time (aPTT) was 49 sec (normal = 26-36) but all other tests of coagulation were normal. ⋯ Seventy-two hours after delivery, she was found to have bilateral leg weakness, urinary incontinence, absent rectal sphincter tone and asymmetrical leg reflexes. The diagnosis of spinal haematoma was confirmed by magnetic resonance imaging. She underwent emergency laminectomy and made a full neurological recovery.