Management of Pain Due to Vaso-Occlusive Crisis (VOC) in Adults with Sickle Cell Disease (SCD) in the Post-Guideline Era: A Retrospective Study in an Urban Medical Center Emergency Department (ED).

Guidelines for managing pain due to VOC published in the United States in 1999 and in England in 2003 suggest

1. prompt initiation of parenteral opioids (within 30 min of arrival);

2. use of an adequate opioid starting dose (5–10 mg or 0.1 mg/kg of morphine intravenously);

3. frequent opioid administration (every 15–30 min) with dose titration if pain is not improved; and

4. individualization of treatment based on the patient’s prior opioid response history.

The impact of these guidelines on actual practices has not been assessed however. Thus, the treatment of adults with uncomplicated VOC at a major urban medical center ED during calender year 2005 was reviewed. The ED protocol during this period called for prompt pain reduction using 4–16 mg of IV morphine every 10–30 minutes according to patient specific protocols. Patients on chronic long-acting opioids, with a history of substance abuse, or with impaired renal or hepatic function were excluded from analysis. A total of 58 visits by 20 patients were evaluable. Inpatient admission was required after 25 visits (43%). Of these admissions, 12 occurred after only 1–3 opioid doses (48%) and 8 occurred within 2 hours of initiating therapy (32%). Opioid treatment was begun within 30 min of arrival in the ED on only 10 occasions (18%) and patients were not treated for >2hr on 18 occasions (32%). Similarly, the interval between the first and second opioid dose was ≤30 min in only 16 of 54 evaluable visits (30%) and >1 hr in 15 of them (28%). Subsequent doses tended to be more frequently delayed with only 6 of 39 patients (15%) receiving a third opioid dose within 30 min of their second treatment. The initial treatment dose was 0.19±0.11 mg/kg of parenteral morphine equivalents with a range of 0.05–0.50 mg/kg. Individual patients tended to receive the same initial dose at each ED visit with 9 usually treated with doses of 0.05–0.1 mg/kg (45%) while 6 consistently required doses >0.2mg/kg (30%). However, dose titration during an ED visit was limited. Thus, in the 10 patients receiving an initial dose <0.1 mg/kg and at least 2 subsequent doses, only 6 (60%) received higher doses during their ED stay and dose escalations did not occur prior to the third dose in 4 of them. Indeed, 2 of these patients did not have an increase in dose until the 4^th and 7^th treatment respectively. Conversely, another patient eventually admitted to the hospital received an initial dose of 0.11 mg/kg but the subsequent 2 doses were only 0.05 mg/kg each. When comparing ED visits which resulted in hospital admission with those in which the patient was able to go home, no significant differences were noted in the mean values for the time to first treatment, time between doses, initial opioid dose or cumulative opioid dose. In summary:

1. both the time to initiation of opioid therapy and the intervals between dosing were usually significantly longer than guideline recommendations;

2. loading dose requirements in individual patients vary greatly with many patients requiring more than twice the usually recommended dose;

3. the decision to admit a patient is often made after only a very brief trial of analgesic therapy; and

4. dose titration in patients with more refractory symptoms is often not done or delayed.

These findings suggest that, despite protocols consistent with current guidelines, timely, effective therapy of VOC in SCD may be compromised in the setting of an overburdened urban ED resulting in delayed pain control and possibly avoidable hospital admissions.