Even Small Doses of Morphine Might Provoke “Luxury Perfusion” in the Postoperative Period after Craniotomy

The Longitudinal Course of Pain and Analgesic Therapy Following Aneurysmal Subarachnoid Hemorrhage: A Cohort Study

“…1 As analgesic therapy with opioids may mask the neurological exam through sedation and miosis or increase cerebral edema through elevation of carbon dioxide concentration, opioids are often avoided in pursuit of patient safety. 11,12 Concerns over opioid safety have been supported by laboratory data that directly link morphine to the attenuation of cerebrovascular reactivity in response to CO 2 in addition to their attenuation of respiratory drive. 13 Yet, earlier studies on the effect of the opioid antagonist naloxone on neurological recovery from SAH in humans did not yield any conclusive benefits.…”

Patient‐controlled analgesia with oxycodone in the treatment of postcraniotomy pain

“…Opioids depress respiration, and may cause retention of CO 2 leading to increased cerebral blood flow and raised intracranial pressure when intracranial compliance is reduced (4,5). Thus, the use of opioids, other than codeine for postcraniotomy pain, is not favoured by neuroanaesthesiologists (3).…”

A review of the efficacy and safety of opioid analgesics post‐craniotomy*

“…Only one study elucidated from the literature demonstrated an increase in arterial CO 2 tension (PaCO 2 ) following increased doses of morphine postcraniotomy (Cold and Felding, 1993). The authors, thus, surmise that even small doses of morphine might cause 'luxury perfusion' and imperil cerebral circulation.…”

“…Opioid-induced respiratory depression is caused by a direct suppression of the respiratory centres of the medulla (Houmes et al, 1992;Cousins and Umedaly, 1996). The resulting retention of carbon dioxide (CO 2 ) can lead to an increase in cerebral blood flow and raised ICP in patients, whose intra-cranial compliance is compromised (Cold and Felding, 1993).…”