Objective: To establish diagnostic criteria for acute mountain sickness (AMS) in preverbal children.
Design: Nonrandomized control trial.
Participants: Children aged 3 through 36 months and adults from the Denver, Colo, area (altitude, 1610 m).
Main outcome measures: The Lake Louise Scoring System was modified, using a fussiness score as the headache equivalent and a pediatric symptom score to assess appetite, vomiting, playfulness, and ability to sleep. Acute mountain sickness was assessed by combining the fussiness and pediatric symptom scores to produce what we termed the Children's Lake Louise AMS Score (CLLS).
Interventions: Parents recorded the fussiness score at 11 AM, 1, 3, and 5 PM, and the pediatric symptom score at 3:00 PM each day. Each subject traveled twice, with 1 day considered a control. Days 1 and 2 were measurements at home; day 3 reflected travel without altitude change to 1615 m; and 1 week later, day 4 involved travel to 3488 m. On days 3 and 4 the accompanying adults completed the Lake Louise Scoring System.
Results: Twenty-three subjects (14 boys; mean+/-SD age, 20.7+/-9.0 months) participated. The mean CLLS demonstrated no differences on days 1, 2, or 3. On day 4, 5 subjects (21.7%) had AMS, established as a CLLS of 7 or higher, and these scores normalized 2 hours after descent. Forty-five adults participated and 9 (20%) had AMS.
Conclusions: We define AMS in preverbal children as a CLLS of 7 or higher with a fussiness score of 4 or higher and a pediatric symptom score of 3 or higher, in the setting of recent altitude gain. The incidence of AMS in preverbal children (21.7%) was similar to that in adults (20%).