Anaesthesia
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Randomized Controlled Trial Clinical Trial
The site of airway irritation during induction of anaesthesia.
The aim of this investigation was to study the role of the nasal airway in mediating upper airway reflexes during induction of anaesthesia when the commonly used irritant inhalational anaesthetic agent enflurane is used. In a prospective randomised study, 40 ASA 1 & 2 day-case patients undergoing body surface surgery were recruited. Following intravenous induction using propofol, 20 patients received enflurane administered via a laryngeal mask airway (LMA), the anaesthetic vapour therefore bypassing the nasal airway. ⋯ We were unable to demonstrate any significant (p < 0.05) differences between the two groups in relation to upper airway complications (cough, breath holding, laryngeal spasm, bronchospasm and excitement). Previous work has identified the nose as a possible important reflexogenic site for upper airway reflexes in humans during anaesthesia. We have been unable to demonstrate any difference in upper airway complications when the nasal airway was included or excluded from exposure to irritant anaesthetic vapours, when administered in a clinical setting.
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Randomized Controlled Trial Comparative Study Clinical Trial
Analgesic and respiratory effect of nalbuphine and pethidine for adenotonsillectomy in children with obstructive sleep disorder.
Opioids may depress respiration and contribute to airway obstruction after adenotonsillectomy for obstructive sleep disorder. We compared the respiratory and analgesic effects of nalbuphine, which has a ceiling effect for respiratory depression, and pethidine in 90 children (aged 2-12 years) with a history of obstructive sleep disorder undergoing adenotonsillectomy. ⋯ Both groups were similar with respect to the demographic data and respiratory measurements: mean (SD) oxygen saturation on air in the recovery area (96.2% (1.2) vs. 96.5% (1.1) in group N and P, respectively) and mean (SD) end-tidal carbon dioxide (46.4 (5.5) mmHg vs. 47.7 (4) mmHg in group N and P, respectively). High obstructive sleep disorder score, history of apnoea, hyperactivity and loud snoring were found to be the best predictors of early postoperative oxygen desaturation in both groups.
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Randomized Controlled Trial Clinical Trial
Comparison of caudal block using bupivacaine and ketamine with ilioinguinal nerve block for orchidopexy in children.
Forty boys weighing less than 25 kg undergoing unilateral orchidopexy were randomly allocated to receive one of two analgesic regimens. Group C received a caudal epidural block with 0.25% bupivacaine 1 ml.kg-1 and preservative-free ketamine 0.5 mg.kg-1; Group L received an ilioinguinal nerve block with 0.25% bupivacaine 0.5 ml.kg-1 and infiltration of the wound with 0.25% bupivacaine 0.5 ml.kg-1. All subjects received diclofenac sodium 1-2 mg.kg-1 as a rectal suppository. ⋯ The median duration of analgesia was 10 h (range 2.6 to > 24 h) in Group C and 2.9 h (range 0.7 to > 24 h) in Group L (p < 0.05). There were no differences between groups in the incidence of motor block, urinary retention, postoperative vomiting or postoperative sedation. Subjects in Group L required significantly more doses of postoperative analgesia than those in Group C (p < 0.05).
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We audited and analysed the adverse effects and safety of postoperative pain management on 2509 consecutive patients under care of the Acute Pain Service at a tertiary referral teaching hospital over a 32-month period. Our standard respiratory monitoring consisted of continuous pulse oximetry, hourly respiratory rate counting, sedation scoring and intermittent arterial blood gas sampling. This protocol was reliable and detected six episodes of bradypnoea, 13 of hypercapnia and 23 of oxygen desaturation occurring in 39 patients (1.8% of all spontaneously breathing patients). ⋯ Postoperative nausea and vomiting decreased analgesic efficacy by discouraging the use of patient-controlled analgesia and was regarded as equally distressing as pain. Other side-effects included: pruritus in 182 patients; dizziness in 333 and lower limb weakness in 73 (21.2% of patients receiving epidural local anaesthetics). It is concluded that a standard monitoring and management protocol, an experienced nursing team and reliable Acute Pain Service coverage is mandatory for the safe use of modern analgesic techniques.
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We describe a novel index derived from the auditory evoked potential, the auditory evoked potential index, and we compare it with latencies and amplitudes related to clinical signs of consciousness and unconsciousness. Eleven patients, scheduled for total knee replacement under spinal anaesthesia, completed the study. The initial mean (SD) value of the auditory evoked potential index was 72.5 (11.2). ⋯ From all parameters studied, Na latencies had the greatest overlap between successive awake and asleep states. The auditory evoked potential index and Nb latencies had no overlap. The consistent changes demonstrated suggest that the auditory evoked potential index could be used as a reliable indicator of potential awareness during propofol anaesthesia instead of latencies and amplitudes.