Post-op analgesia can impair cognition

LAST year Laura Scott, a neuro­psychology researcher from Macquarie University, presented the results of a systematic review of 52 randomised controlled trials that looked at the cognitive effects of opioid analgesics when used to manage postoperative pain in patients who were ‘opioid naive’. 

She discovered that although almost all cognitive domains could be affected, attention, psychomotor skills and executive function were particularly susceptible, and that it wasn’t just the dose, but the specific opioid used, as well as the route of administration, that influenced the type of impairment. 

“Opioid receptors are widely distributed in a non-uniform way, so different drugs can produce different patterns of impairment based on their... receptor affinity,” Ms Scott explains.

The results question the validity of equianalgesic dosing.

“Just because two drugs might give the same amount of pain