Evaluation of Diagnostic Criteria and Incidence of Acute Mountain Sickness in Preverbal Children

The Children's Lake Louise Score (CLLS) established the diagnostic criteria for acute mountain sickness (AMS) in preverbal children. Prospective application of the CLLS and interobserver agreement for the score had not been evaluated in a controlled trial. A study of children and their parents was used to evaluate the CLLS and determine the incidence of AMS in preverbal children. A prospective, controlled trial. Children ≥3 months and ≤36 months old and their parents living below 1645 m were studied over 7 separate days. The CLLS, measured daily by the mother as well as by the father on days 5 and 6, is the sum of scores for fussiness (FS), eating (E), playfulness (P), and sleep (S). Children were studied on days 1 and 2 at home, on day 3 after travel without altitude gain to a hotel, on day 4 at home, on days 5 and 6 at a hotel at 3109 m, and on day 7 at home. Using our previous criteria, AMS was diagnosed if the CLLS was ≥7 with both the FS ≥4 and the E + P + S ≥3. Agreement between mothers’ and fathers’ CLLS values was measured with the kappa statistic (κ). Adults were also evaluated for AMS by the CLLS on days 5 and 6. Thirty-seven children (mean age ± SD = 16.5 ± 10.5 months; 21 girls) participated, and AMS occurred in 7 of them (19%; 95% CI, 8.35%). Among 33 adults, 8 (24%; 95% CI, 9.39%) had AMS. Although the agreement of the parents on the CLLS components was poor, the agreement on the classification of AMS between mother and father was excellent (κ = .67; P < .001), with both parents’ scores exceeding the CLLS threshold for AMS. In this prospective trial, parents demonstrated excellent interobserver agreement for independent use of the CLLS to detect AMS. Consistent with our previous retrospective study, the incidence of AMS at moderate altitude in preverbal children (19%) was similar to that in adults (24%).