The best questions often stem from the inquisitive learner. As educators, we love, and are always humbled by, those moments when we get to say, “I don’t know.” For some of these questions, you may already know the answers. For others, you may never have thought to ask the question. For all, questions, comments, concerns, and critiques are encouraged. Welcome to the Kids Korner.
Question 1: In children with a closed head injury and no head imaging in the emergency department, will ondansetron mask a significant intracranial injury?
While we commonly see closed head injuries and concussions, there are very few data addressing this question. We found two articles evaluating ondansetron administration and closed head injury, and neither thoroughly address giving ondansetron as a discharge prescription. The first article by Kinnaman et al is a survey of emergency medicine providers, of which 90 percent (238 of 265 total respondents) treated only children in their practice environment.1 The response rate of the survey was noted to be 29 percent. This study addresses practitioner management of concussion only, finding that 142 of 265 (54 percent) of surveyed practitioners treat concussion with ondansetron. There is no mention of whether this is an ED dose only, home prescription, or combination of the two. While this study is a survey and subject to a number of biases, one conclusion that may be drawn is that it is not uncommon to treat concussion with ondansetron.
The other study is a retrospective study of two tertiary emergency departments over the course of eight years (n=28,271 total patients) by Sturm et al.2 The primary outcome was evaluating for return visits within 72 hours in children (6 months to 18 years of age) who received a head CT in the pediatric emergency department (PED) and who did and did not receive ondansetron in the PED. The secondary outcome evaluated bounce backs in children who got admitted (within 72 hours) who did not receive a head CT in the PED initially and assessed whether ondansetron masked any “missed cases,” defined as skull fracture or intracranial hemorrhage. This secondary outcome analysis best addressed our clinical question.
During this eight-year period, there were 21,595 children seen in the PED for head injury who did not receive a head CT. For these discharged children without head CT, 433 of 21,595 (2 percent) received ondansetron during their PED stay, of which 12 patients (2.8 percent) returned within 72 hours. For children who did not get a head CT and did not get ondansetron during their PED visit, 1.8 percent (385 of 21,162) returned within 72 hours. There was no statistically significant difference between these two groups (P=0.105). After controlling for acuity and demographics, ondansetron had no significant effect on return rates (odds ratio 1.15; 95% CI, 0.56–2.36). Of the 433 patients in the non–head CT group who received ondansetron in the PED at initial presentation, there were no missed diagnoses (0 of 433). In the non–head CT group who did not receive ondansetron, there were seven missed diagnoses (7 of 21,162 patients; P=0.36), and this finding was not statistically significant. The authors do not mention or address how many children in the non–head CT group got a home prescription for ondansetron, so no definitive conclusions can be drawn based on the current literature.