Epidural and intrathecal morphine in intensive care units

Analgesia and sedation for patients in intensive care units (ICU) who require mechanical ventilation are most commonly provided by intermittent i.v. injections of opiates and benzodiazepines. However, the technique has a number of disadvantages. Also, in many cases these drugs are inadequate, even in large doses, and muscle relaxants may be necessary for patient respirator coordination. The analgesic effect of epidural and intrathecal morphine was studied in 24 ICU patients requiring controlled ventilation. In spite of large doses of phenoperidine, diazepam and a number of other analgesics and sedatives, all patients were restless, agitated and coordinated poorly with the respirator. Through an indwelling epidural catheter morphine (4 mg) was injected intermittently as required in 11 patients and as a continuous infusion (20-40 mg/day) in five patients. In eight patients morphine (2-4 mg) was injected intrathecally as a single injection. Both epidural and intrathecal morphine gave potent analgesia and good patient respirator coordination. The duration of analgesia was shortest after intermittent injections of epidural morphine and longest after intrathecal morphine. However, continuous infusion of morphine in the epidural catheter appears to be the most practical method. In patients with multiple trauma and in patients where frequent assessment of the level of consciousness is important this technique is superior to parenteral analgesic sedative combinations. Intrathecal morphine may be indicated in patients in a compromised position. The daily analgesic requirement can be reduced by about 10-100 times by the use of epidural and intrathecal morphine respectively.