Pain resulting from sickle-cell vaso-occlusive crisis (VOC) is often severe, prolonged and difficult to alleviate. Guidelines based on scientific evidence are lacking. In order to evaluate the effectiveness of our treatment protocol, we performed a population-based retrospective observational study on HbSS sickle-cell patients (n=22) admitted for severe VOC (n=48) during a 30-months period and managed with patient controlled analgesia (PCA).
Median (10th-90th percentiles) visual analogical pain scale (VAS) at admission was 9.5(7–10). Patient received 0.3mg/kg (0.1–0.4) intravenous morphine at admission, then PCA was started with the following settings: continuous rate: 20 µg/kg/h (10–25), bolus: 25µg/kg (21–32), and 1.8 bolus allowed/hour (1.7–2.8). Six hours after admission, VAS was less than 7 in only 41% of cases. The median VAS declined steadily during hospitalization. Pain intensity was not correlated with morphine dosage. Success 6 hours after admission (VAS< 7) and during hospitalization (VAS£4) was associated with significantly lower VAS score at admission and lower number of VOC during the study period. Patients who experienced >2 CVO/year have the following characteristics: higher VAS at admission, higher morphine dosages, lower success rate and lower CRP, bilirubin, LDH and reticulocyte count.
The difficulties encountered in the management of patients who experienced >2 VOC/year may be related to their genotypic particularities. For such patients, an increase of morphine dosage is required. We have developed a computer routine in order to reduce time and increase accuracy of PCA prescription, and to build a prospective database that enables continuous assessment of our treatment protocol.