Intermittent injection vs patient-controlled analgesia for sickle cell crisis pain. Comparison in patients in the emergency department

Abstract

Background: --The purpose of this study is a prospective assessment of morphine sulfate administration by intermittent intravenous (IV) injections (Int-IV) vs patient-controlled analgesia (PCA) in patients in the emergency department (ED) with sickle cell crisis pain.

Methods: --Patients were at bed rest and received intravenous hydration. Linear analog scale for pain intensity and verbal pain scale, level of alertness, and vital signs were assessed prior to therapy, every 60 minutes thereafter, and at the time of discharge from the ED. Patients were randomized to Int-IV or PCA. During phase 1, patients in the Int-IV group received morphine sulfate 4 mg IV every 30 to 60 minutes as necessary for a linear analog scale for pain intensity greater than 50 mm. The patients in the PCA group received morphine sulfate 2 mg bolus then 1.0 mg with a 6-minute lockout. During phase 2, patients in the Int-IV group received morphine sulfate 8 mg IV every 30 to 60 minutes as necessary for a linear analog scale for pain intensity greater than 50 mm. The patients in the PCA group received morphine sulfate 5 mg bolus then 2.7 mg with a 10-minute lockout. Data were analyzed by unpaired t test, general linear modeling, Mann-Whitney U test, and chi 2 test.

Results: --During phase 1, 10 patients (28.3 +/- 7.3 years) received Int-IV and 10 patients (33.9 +/- 12.5 years) received PCA. Treatment groups did not differ significantly regarding duration of pain, amount of morphine administered, linear analog scale for pain intensity, verbal pain scale, level of alertness, or vital signs except for a significantly lower final respiratory rate with Int-IV. In phase 2, 12 patients (28.4 +/- 5.6 years) received Int-IV and 13 patients (26.8 +/- 8.1 years) received PCA. The PCA groups had a significantly shorter elapsed time between onset of pain and treatment (7.3 +/- 6.5 hours) when compared with the Int-IV group (18 +/- 16.9 hours). Treatment groups did not differ significantly with respect to total amount of morphine administered, linear analog scale for pain intensity, verbal pain scale, vital signs, or level of alertness. The PCA group had a significant reduction in length of stay in the ED during phase 2 when compared with phase 1. The ED discharge rate and the incidence of side effects did not differ significantly between groups.

Conclusion: --At both the low- and high-dose regimens, PCA is equally safe and effective and may be used in place of Int-IV administration of morphine in the ED treatment of sickle cell crisis pain.