British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the analgesic potency of xenon and nitrous oxide in humans evaluated by experimental pain.
We have compared the analgesic potency of MAC-equivalent concentrations of xenon (10, 20, 30 and 40%) and nitrous oxide (15, 30, 45 and 60%) in humans using a multimodal experimental pain testing and assessment technique. We tested 12 healthy volunteers in a randomized, single-blind, crossover study. The following experimental pain tests were used: nociceptive reflex to repeated stimuli; pain tolerance to maximal effort tourniquet ischaemia; electrical stimulation; mechanical pressure; and cold. ⋯ There was no difference in MAC-equivalent concentrations of xenon and nitrous oxide. Both increased reaction time in a similar manner. Xenon and nitrous oxide evoked nausea and vomiting in a large number of volunteers.
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Randomized Controlled Trial Clinical Trial
Dextromethorphan and pain after total abdominal hysterectomy.
Dextromethorphan is an N-methyl-D-aspartate (NMDA) receptor antagonist which has been shown to inhibit the development of cutaneous secondary hyperalgesia after tissue trauma. We studied 60 ASA I-II patients undergoing total abdominal hysterectomy in a randomized, double-blind, placebo-controlled study. Patients received either dextromethorphan 27 mg capsules, two doses before operation and three doses in the first 24 h after operation, or placebo. ⋯ Evidence of secondary hyperalgesia was assessed with von Frey hairs 10 cm above the Pfannenstiel incision. Both groups of patients exhibited evidence of secondary hyperalgesia after 24 and 48 h but there were no significant differences between groups. There was also no difference between groups in VAS scores at 1 month.
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Randomized Controlled Trial Clinical Trial
Neostigmine with glycopyrrolate does not increase the incidence or severity of postoperative nausea and vomiting in outpatients undergoing gynaecological laparoscopy.
We studied 100 healthy women undergoing outpatient gynaecological laparoscopy in a randomized, double-blind and placebo-controlled study to evaluate the effect of neostigmine on postoperative nausea and vomiting (PONV). After induction of anaesthesia with propofol, anaesthesia was maintained with sevoflurane and 66% nitrous oxide in oxygen. Mivacurium was used for neuromuscular block. ⋯ The severity of nausea and vomiting, worst pain, antiemetic and analgesic use, times to urinary voiding and home readiness were recorded. During the first 24 h after operation, 44% of patients in the neostigmine group and 43% in the saline group did not have PONV. We conclude that neostigmine with glycopyrrolate did not increase the occurrence of PONV in this patient group.
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Randomized Controlled Trial Clinical Trial
Effect of remifentanil on the auditory evoked response and haemodynamic changes after intubation and surgical incision.
We have observed the effect of intubation and incision, as measured by the auditory evoked response (AER) and haemodynamic variables, in 12 patients undergoing hernia repair or varicose vein surgery who received remifentanil as part of either an inhaled anaesthetic technique using isoflurane or as part of a total i.v. technique using propofol. Anaesthesia was induced with remifentanil 1 microgram kg-1 and propofol, neuromuscular block was achieved with atracurium 0.6 mg kg-1 before intubation, and anaesthesia was maintained with a continuous infusion of remifentanil in combination with either a continuous infusion of propofol or inhaled isoflurane. The AER and haemodynamic variables were measured before and after intubation and incision. ⋯ When the data for the two anaesthetic combinations were pooled, the only significant effects were increases in diastolic arterial pressure and heart rate immediately after intubation; these were not seen 5 min after intubation. There were no cardiovascular responses to incision. There were no significant changes in the AER after intubation or incision.
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Randomized Controlled Trial Clinical Trial
A single dose of milrinone facilitates separation from cardiopulmonary bypass in patients with pre-existing left ventricular dysfunction.
Milrinone is used during cardiac surgery to facilitate separation from cardiopulmonary bypass (CPB) and/or to treat myocardial dysfunction in the post-bypass period. We have demonstrated, in patients with preoperative depression of systolic function undergoing aorto-coronary artery bypass surgery, sustained improvement in cardiac function after a single loading dose of milrinone 50 micrograms kg-1, administered at the end of bypass, thus significantly decreasing the need for beta-agonist therapy.