Critically ill pediatric patients frequently receive prolonged
analgesia and sedation to provide
pain relief and facilitate
intensive care therapies. Iatrogenic withdrawal syndrome occurs when these drugs are stopped abruptly or weaned too rapidly. We investigated the validity and generalizability of the Withdrawal Assessment Tool-1 (WAT-1) in children during weaning of
analgesics and
sedatives. Of 308 children initially supported on
mechanical ventilation for acute
respiratory failure, 126 (41%) from 21 centers (median age 1.6 years; interquartile range 0.6-7.7 years) were exposed to 5 or more days of
opioids. Subjects were assessed for
withdrawal symptoms with the WAT-1, an 11-item (12-point) scale, from the first day of weaning from
analgesia/sedation until 72 h after the last
opioid dose. A total of 836 daily WAT-1 assessments were completed, with a median (interquartile range) WAT-1 score of 2 (0-4) over 6 (3-9) days per subject. There were no significant differences in WAT-1 scores as a function of age. Factor analyses confirmed that motor-related symptoms and behavioral state accounted for the most variance in WAT-1 scores. Supporting construct validity, cumulative
opioid exposures were greater [40.2 (19.7-83.4) vs 17.6 (14.6-39.7) mg/kg, P=.004], length of
opioid treatment before weaning was longer [7 (6-11) vs 5 (5-8)days, P=.004], and length of weaning from
opioids was longer [10 (6-14) vs 6 (3-9)days, P=.008] in subjects with WAT-1 scores of ≥ 3 compared to subjects with WAT-1 scores of <3. The WAT-1 shows good psychometric performance and generalizability when used to assess clinically important
withdrawal symptoms in pediatric
intensive care and general ward settings.