Patient-controlled analgesia versus continuous infusion of morphine during vaso-occlusive crisis in sickle cell disease, a randomized controlled trial

Intravenous morphine is the treatment of choice for severe pain during vaso- occlusive crisis in sickle cell disease (SCD). However, side effects of morphine may hamper effective treatment, and high plasma levels of morphine are associated with severe complications such as acute chest syndrome. Furthermore, adequate dosing remains a problem since no objective measurement of pain severity exists and analgesia should be titrated upon the patient's reported pain. Patient-controlled analgesia (PCA) may therefore be an interesting alternative since patients can titrate the level of analgesia themselves. In this randomized controlled study, the efficacy of intravenous morphine administration with PCA was compared with continuous infusion (CI) of morphine in patients with SCD during vaso-occlusive crisis. Twenty five consecutive episodes of vaso-occlusive crisis in 19 patients with SCD were included in the study. Patients in the PCA-group had a markedly and significant lower mean and cumulative morphine consumption when compared with the patients in the CI-group (0.5 mg/hr versus 2.4 mg/hr (P < 0.001) and 33 mg versus 260 mg (P = 0.018, respectively). The mean daily pain scores were comparable (4.9 versus 5.3). The lower mean and cumulative morphine consumption in the PCA-group led to significant less nausea and constipation during treatment when compared with the CI-group (area under the curve, respectively, 11 versus 18 (P = 0.045) and 30 versus 45 (P = 0.021). Furthermore, a nonsignificant reduction in the duration of hospital admission of 3 days was observed in the PCA-group. PCA results in adequate pain relief at a much lower morphine consumption and should considered to be the first choice in morphine administration to sickle cell patients admitted with vaso-occlusive crisis.