Does Time-to-Opioid Administration in the Emergency Department Affect Outcomes for Uncomplicated Acute Pain Crises in Children with Sickle Cell Disease?.

The acute painful crisis is the clinical hallmark of sickle cell disease (SCD). Recently, time-to-opioid administration (TTO) has been suggested as quality-of-care (QOC) measure for SCD patients with an acute painful crisis (Wang,Pediatrics,128:484,2011). We sought to determine whether TTO was associated with outcomes of emergency department (ED) visits for acute painful crisis.

We conducted a retrospective cohort study of ED visits for acute painful crisis to Children's Medical Center Dallas between 1/1/2008 and 12/31/2010. Potential subjects were identified by query of hospital administrative records using all ICD-9CM codes for SCD (282.41, 282.42, and 282.6x) as either the primary or a secondary diagnosis. We included patients with any SCD genotype between 5 and 18 years of age. Records of all potential subjects were reviewed to determine whether the episode represented an acute painful crisis, defined as the recent onset of acute pain not explained by other mechanisms. We excluded patients with confounding sources of pain (e.g., headache and gallstones), patients transferred from other medical centers, and patients who had a surgical procedure within 2 weeks of presentation. We also excluded patients who received a simple transfusion in the preceding 30 days or were part of a chronic transfusion program in the preceding 6 months. The primary predictor variable was TTO in minutes, analyzed continuously and in quartiles. The primary outcome variable was hospital admission with secondary outcomes of change in pain scores 1 & 2, area under the curve (AUC) for pain scores at 4 hours (pain score AUC), and length of stay in the ED (ED LOS) in minutes. Univariate mixed regression (logistic for admission, linear for other outcome variables), including patient random effects, was used to test for association between TTO and other relevant covariates with the outcome variables. Variables with P-values <0.10 in the univariate regression models were subsequently evaluated in multivariate mixed models.

From 2,866 ED visits in 2008–2010, 177 subjects were identified with 416 presentations for acute painful crisis treated with IV opioids. 47% of subjects were female and 65% had HbSS/HbSβ0. The primary outcome, inpatient admission, occurred in 53% of ED visits. The median TTO was 86 minutes (intraquartile range (IQR) 54 – 130 minutes) and was not different between those admitted and not admitted to the hospital (not admitted - 86.5 minutes, (IQR 56.5, 126.5); admitted - 85.5 minutes, (IQR 50.5, 130)). TTO (both as a continuous and categorical variable) was not associated with inpatient admission in either univariate or multivariate analyses. In multivariate analyses with secondary outcomes, TTO was associated with change in pain scores 1 & 2, pain score AUC at 4 hours, and ED LOS. After adjusting for age and initial pain score, decreased TTO was independently associated with a decrease in pain scores 1 & 2 (referent - TTO Quartile 4 (>131 minutes) vs Quartile1 (<56 minutes), β coefficient = 0.49, 95% Confidence Interval (CI) [0.08, 0.89], p=0.019). After adjusting for age, decreased TTO was independently associated with a decreased pain score AUC (referent - TTO Quartile 4 vs Quartile 1, β coefficient = −81, 95% CI [−153, −9], p=0.027). Finally, after adjusting for admission status, decreased TTO was independently associated with decreased ED LOS (referent – TTO Quartile 4 vs Quartile 1, β coefficient = −131, 95% CI [−191, −72], p=<0.001).

For acute painful crisis, TTO in the ED setting has been suggested as a QOC measure. While TTO is not associated with our primary outcome, inpatient admission, it is independently associated three other important outcomes: change in pain scores 1 & 2, pain score AUC, and ED LOS. The association of the process measure, TTO, with these outcomes increases the appeal for its use in broader sickle cell populations and should lead to necessary steps to reduce TTO in the ED setting. Subsequent studies should investigate TTO in other SCD populations including adults, examine determinants of prolonged TTO, and study interventions designed to reduce TTO in various ED settings.

No relevant conflicts of interest to declare.