Validity and reliability of head lift and tongue depressor test for diagnosis of the residual block

ABSTRACT

BACKGROUND: Head lift (HL) for 5 seconds and tongue depressor (TD) test have been used for diagnosis of the residual block after using the nondepolarizing muscle relaxants. We investigated validity and reliability of HL, TD, and both of them (HLTD). METHODS: Four-hundred-thirteen patients were enrolled in this study. Neuromuscular blockade was maintained with rocuronium and reversed with pyridostigmine and glycopyrrolate. TOF ratio was quantified by acceleromyograph in the recovery room. HL and TD test were performed in the patients who could respond to verbal command of the investigator. We analyzed the sensitivity, specificity, positive and negative predictive value, positive and negative likelihood ratio, area under the cure (AUC) from ROC analysis and kappa statistics. RESULTS: Prevalences of residual block were 13%, 32% and 78% at 0.7, 0.9 and 1.0 of TOF ratio cutoff value, respectively. Specificity was good for HL (79.7-86.8%), TD (94.2-97.8%) and HLTD (77.8-85.7%), but sensitivity was not. Positive predictive value was higher in TD than HL and HLTD, and negative predictive value was similar among them. Positive and negative likelihood ratio was higher in TD than HL and HLTD. AUC had no difference among HL, TD and LTD. Kappa statistics were showed minimal or moderate relationship between clinical test and train of four responses. CONCLUSIONS: We concluded that HL, TD and HLTD were not good tools for diagnosis of the residual block in a view of validity and reliability.