Prevalence of anemia in children presenting with apparent life-threatening events.

BACKGROUND: Anemia has been associated with apparent life-threatening events (ALTEs) in children. However, the nature of the association has not been well described.

OBJECTIVES: This study was conducted to determine how often anemia occurs in children presenting with ALTEs. Specifically, the authors sought to prospectively describe hemoglobin (Hb) levels and mean corpuscular volumes (MCVs) in children presenting with either a single ALTE or recurrent events, and to compare the values with those of an age-matched control population. Patients who had recurrent events were compared with those who had single events because it was hypothesized that patients who were anemic would be more likely to have recurrent events.

METHODS: This was a prospective cohort study set in an urban, tertiary care emergency department of a large children's hospital. Children presenting with ALTEs and an age-matched control population were included. The mean Hb level, mean MCV, mean value for the mean corpuscular hemoglobin (MCH), and proportion of patients found to be anemic were measured.

RESULTS: Of 128 patients evaluated during the two-year study period, 108 were eligible for study and were age-matched to 108 control patients. Overall, the ALTE and control patients were similar with regard to age, gender, and race. However, the ALTE patients with recurrent events (37/108, 34.3%) were older (3.0 months vs. 1.6 and 2.1 months, p = 0.018) and had a lower mean Hb level (11.6 g/dL vs. 13.1 and 12.9 g/dL, p = 0.013), a lower MCH (30.3 fL vs. 33.1 and 32.4 fL, p < 0.001), and a lower MCV (88.4 pg vs. 96.6 and 93 pg, p < 0.01) than did the patients with a single event and the control patients, respectively. The rate of anemia in the ALTE patients with recurrent events was 21.6%, as compared with 16.9% of the patients with a single event (p = 0.13) and 9.3% of the control patients (p = 0.049).

CONCLUSIONS: Anemia is common in pediatric patients with recurrent ALTEs. Patients with recurrent ALTEs are older and have lower Hb, MCH, and MCV values than patients with a single ALTE and age-matched control patients. Significantly lower MCH and MCV values in patients with recurrent ALTEs suggest that iron deficiency may be associated with the recurrence of events.