A Comparison of Alfentanil Requirements in European and Asian Patients during General Anaesthesia

Abstract

Alfentanil requirements were compared in thirty-six Asian and forty-three European patients during general anaesthesia with muscle relaxants. Alfentanil infusion at 5 jlg/kg/min was started immediately after induction with thiopentone and alcuronium. The infusion rate was reduced to 0.5 jlg/kg/min after ten minutes. An incremental dose of5 jlg/kg/minfor five minutes was given on each occasion when anaesthesia was clinically judged to be inadequate. Recovery parameters were recorded. Pharmacokinetics were also studied in five Europeans, four Chinese and four Nepalese. The dosage of alfentanil required was comparable in both Asian and European patients, but recovery was slower in the Asian patients. The elimination ha(f-/ife in the Chinese and the Nepalese were both significantly shorter than that of the Europeans (P < 0.05), but at the time of recovery of spontaneous ventilation, the mean plasma concentrations were not significantly different.

Association of Ethnicity with the Minimum Alveolar Concentration of Sevoflurane

“…[23][24][25] Houghton et al 25,26 concluded that ethnicity affected recovery from suxamethonium and from anesthesia, with Europeans recovering faster than Asians. The same authors also found that although the elimination half-life of alfentanil in Chinese and Nepalese patients were both significantly shorter than that of Europeans, mean plasma concentrations did not differ significantly at the time of recovery of spontaneous ventilation.…”

“…The same authors also found that although the elimination half-life of alfentanil in Chinese and Nepalese patients were both significantly shorter than that of Europeans, mean plasma concentrations did not differ significantly at the time of recovery of spontaneous ventilation. 23 A study of postoperative morphine consumption revealed that there were significant differences in the dose of analgesics administered to black, Hispanic, and white patients. 27 Other studies, though, did not identify ethnic differences in the sensitivity to analgesics.…”

“…28 Furthermore, investigators have suggested that differences in sensitivity are probably related to factors other than ethnicity. 29 Aun et al, 23 for example, showed that alfentanil had a similar analgesic effect when administered during general anesthesia in both European and Asian patients, although the recovery was slower in Asian patients. Hispanic patients were less likely to receive analgesic in the emergency ward than were non-Hispanics.…”

Suxamethonium myalgia: an ethnic comparison with and without pancuronium pretreatment

“…The slower recovery of the Asians from anaesthesia is difficult to explain but it supports the work of Aun and colleagues [21] who found slower recovery from anaesthesia in Asians given alfentanil by infusion as a supplement to nitrous oxide and muscle relaxant anaesthesia and also that of Houghton and colleagues [22] who found greater sedation in Asians following pethidine analgesia after upper abdominal surgery.…”

Effect of cultural background and healthcare environment on postoperative opioid requirement

“…It is also commonly believed that Asians are more reluctant to report pain and have a greater fear of opioids than Caucasians. [5][6][7] Despite these assertions, few studies have evaluated the influence of ethnicity on postoperative pain. [2][3][4][5] Our group have recently reported findings from a prospective cohort comparing opioid requirement and postoperative pain in a matched group of 136 Chinese patients from Hong Kong and Caucasian patients in Melbourne who received major surgery.…”