Validation of the pictorial Baxter Retching Faces scale for the measurement of the severity of postoperative nausea in Spanish-speaking children.

BACKGROUND: As the intensity of nausea, a subjective symptom, is difficult to estimate in children, vomiting is used as the objective clinical endpoint in managing paediatric postoperative nausea and vomiting. The pictorial Baxter Retching Faces (BARF) scale is a validated quantitative measure of paediatric nausea, but versions in languages other than English have not been validated.

METHODS: Healthy Spanish-speaking children aged 7-18 yr (n=184) undergoing elective ambulatory surgery rated perioperative pain and nausea using visual analogue (VAS) and pictorial Faces Pain Scale - Revised and BARF scales, along with a Likert scale measurement of symptom changes. Parents kept a post-discharge diary.

RESULTS: Postoperative BARF scores were significantly higher in patients receiving anti-emetics {mean [standard deviation (sd)]: 4.6 (3.4) vs 0.9 (1.6); P<0.001}. Nausea scores obtained prior to rescue anti-emetics were higher than preoperative values [mean (sd) increase: 4.0 (3.6); P<0.001], and decreased after therapy [decrease: 2 (2.4); P=0.03]. The Spearman correlation [95% confidence interval (CI)] between the BARF and VAS nausea scores was 0.72 (0.64-0.78), and significantly stronger than BARF and pain score correlation [0.3 (0.1-0.4)]. The minimum (sd) clinically relevant difference was 1.2 (1.7) for both BARF and VAS nausea scales. The intra-class coefficient (95% CI) of BARF scores was 0.88 (0.76-0.94). The BARF scale had excellent performance in predicting patient-perceived need for anti-emetics (area under the curve-receiver operating characteristic: 0.899; 95% CI: 0.82-0.98).

CONCLUSIONS: The BARF scale has construct, convergent, discriminant, and test-retest validity in measuring nausea severity in Spanish-speaking children, and may be a useful instrument in the management of paediatric postoperative nausea and vomiting.

CLINICAL TRIAL REGISTRATION: NCT02007109.