Genetic variation at position 118 of the mu-opioid receptor is associated with interindividual differences in pain scores, self-administered intravenous morphine, and the incidence of nausea postoperatively.

GlaxoSmithKline Biologicals SA.

BackgroundMorphine consumption can vary widely between individuals even for identical surgical procedures. As mu-opioid receptor (OPRM1) is known to modulate pain perception and mediate the analgesic effects of opioid compounds in the central nervous system, we examined the influence of two OPRM polymorphisms on acute post-operative pain and morphine usage in women undergoing elective caesarean delivery.ResultsData on self-reported pain scores and amount of total morphine use according to patient-controlled analgesia were collected from 994 women from the three main ethnic groups in Singapore. We found statistically significant association of the OPRM 118A>G with self-administered morphine during the first 24-hour postoperative period both in terms of total morphine (p = 1.7 × 10-5) and weight-adjusted morphine (p = 6.6 × 10-5). There was also significant association of this OPRM variant and time-averaged self-rated pain scores (p = 0.024). OPRM 118G homozygotes used more morphine and reported higher pain scores than 118A carriers. Other factors which influenced pain score and morphine usage include ethnicity, age and paying class.ConclusionOur results suggest that ethnicity and OPRM 118A>G genotype are independent and significant contributors to variation in pain perception and postoperative morphine use in patients undergoing cesarean delivery.

SummaryThe GlideScope Ò is a new video laryngoscope developed for management of the difficult airway. We compared the GlideScope with the Macintosh laryngoscope in simulated easy and difficult laryngoscopy. Twenty anaesthetists were allowed three attempts to intubate in each of four laryngoscopy scenarios in a high fidelity simulator. In the simulated easy laryngoscopy scenarios, the anaesthetists took longer to intubate using the GlideScope than the Macintosh laryngoscope (mean (SD) 19.0 (9.7) s vs. 12.7 (5.9) s, respectively; p = 0.006). There was no difference in the number of successful intubations, ease of intubation or choice of intubating device. In the simulated difficult laryngoscopy scenarios, the anaesthetists took less time to intubate using the GlideScope (23.5 (12.7) s vs. 70.5 (101.2) s, respectively; p = 0.001). The slightly higher success rate with the GlideScope was not statistically significant (20 ⁄ 20 vs. 18 ⁄ 20, respectively; p = 0.5). However, the anaesthetists found it easier to intubate using the GlideScope (median (interquartile range [range]) 1 (1-2 [1-2]) vs. 2 (2-3 [1-3]), respectively; p < 0.0001).

Our study showed that PCEA+AMB reduced analgesic consumption and could be useful as the mode of maintenance for epidural analgesia.