Clinical Use of the Pictorial Baxter Retching Faces Scale for the Measurement of Postoperative Nausea in Children

Because nausea is difficult to evaluate in children, vomiting is used as the objective clinical end point in managing pediatric postoperative nausea and vomiting and postdischarge nausea and vomiting (PDNV). The recently developed pictorial Baxter Retching Faces (BARF) scale has content, construct, and convergent validity in quantifying pediatric nausea intensity. We determined its clinical usefulness in assessing pediatric postoperative nausea and vomiting and PDNV, establishing the lowest age associated with consistently reliable use, the score at which patients identify a need for therapy, and the minimum clinically relevant change in scores, and examined its test-retest reliability.

We obtained subject ratings of the severity of their nausea using the BARF and visual analog scales in the preoperative, postanesthesia care unit and postdischarge phases. Changes in nausea were rated on a 5-point Likert scale, along with responses to queries of a need for rescue antiemetics at these time points.

Children ≥6 years of age had a consistently reliable ability to use the BARF scale (132/132 [100%] vs 59/76 [77.6%] for children ≥6 and <6 years of age, respectively, Fisher exact test, P < .001). The BARF scale had excellent performance in predicting patient-perceived need for antiemetics, with a score of 4 having 80.0% sensitivity and 85.6% specificity. The minimum clinically relevant difference in BARF scores was 1.47 (95% confidence interval, 0.84-2.1). The intraclass correlation coefficient was 0.56 (95% confidence interval, 0.34-0.73).The BARF scale identified 60 of 192 (31.3%) children as having postoperative nausea in the postanesthesia care unit, with severe nausea (score >6) in 13 (6.7%). Emesis occurred in 8 (4.1%). Rescue antiemetics were administered to 16 (8.3%), including 2 with severe emesis (≥3 episodes) but in only 2 of 11 (18.2%) with severe nausea without vomiting. PDNV was reported in 39 of the 99 who returned diaries (39.4%), with nausea in 34 (34.3%), severe nausea in 15 (15.2 %), and emesis in 16 (16.2%).

The pictorial BARF scale is easy to use in the clinical setting by children ≥6 years of age, has a minimum clinically relevant difference of 1.47, with scores of 4 or higher associated with a patient-identified need for rescue antiemetics. Assessment of postoperative nausea by the BARF scale has shown that clinically significant nausea occurs frequently in children but is not always treated unless accompanied by vomiting.