As
pain in the intensive care unit (ICU) is still common despite important progress in
pain management, we studied the efficacy of an intravenous bolus of
morphine 2.5 vs 7.5 mg for
procedural pain relief in patients after cardiothoracic surgery in the ICU. In a prospective double-blind randomised study, 117 ICU patients after cardiothoracic surgery were included. All patients were treated according a
pain titration protocol for
pain at rest, consisting of continuous
morphine infusions and
paracetamol, applied during the entire ICU stay. On the first postoperative day, patients were randomised to intravenous
morphine 2.5 (n=59) or 7.5 mg (n=58) 30 minutes before a painful intervention (turning of patient and/or chest drain removal).
Pain scores using the numeric rating scale (Numeric Rating Scale, range 0 to 10) were rated at rest (baseline) and around the painful procedure. At rest (baseline), overall incidence of unacceptable
pain (Numeric Rating Scale ≥4) was low (Numeric Rating Scale >4; 14 vs 17%, P=0.81) for patients allocated to
morphine 2.5 and 7.5 mg respectively. For procedure-related
pain, there was no difference in incidence of unacceptable
pain (28 vs 22%, P=0.53) mean
pain scores (2.6 [95% confidence interval 2.0 to 3.2] vs 2.7 [95% confidence interval 2.0 to 3.4]) between patients receiving
morphine 2.5 and 7.5 mg respectively. In
intensive care patients after cardiothoracic surgery with low
pain levels for
pain at rest, there was no difference in efficacy between intravenous
morphine 2.5 mg or
morphine 7.5 mg for
pain relief during a painful intervention.