Significance of pupillary diameter variation in assessment of postoperative pain / 临床麻醉学杂志

ABSTRACT

Objective To observe the reactivity of pupillary diameter variation responding to numerical rating scale on postoperative pain to explore the accuracy of pupillary diameter variation for pain assessment.Methods Eighty patients after selected surgery (male 43 cases,female 37 cases,aged 24-79 years,ASA gradeⅠorⅡ)were included for the trial.After endotracheal extubation and on arri-val in the post-anaesthesia care unit (PACU),the levels of pain on numerical rating scale (NRS)were rated and recorded subsequently.If NRS was within 0-3,no analgesic was administered and 50 μg fentanyl was administrated after 5 min if NRS rated in 4-10.The pupillary diameter (PD),systolic blood pressure (SBP)and heart rate (HR)were recorded every minute during 20 minute after first NRS evaluation,the corresponding maximum variation of above index were calculated simultaneously in 10 minutes with NRS 0-3,after 5 minutes with NRS 0-3 to 4-10,after 5 minutes with NRS 4-10 to 0-3,in 10 minutes with NRS 4-10 which were marked respectively with ΔPD,ΔSBP and ΔHR.With the variation of NRS as a criterion,the reactivity of ΔHR,ΔSBP and ΔPD responding to NRS varia-tion were assessed by analysing the receiver operating characteristic curve (ROC),the area under the receiver operating characteristic curve (AUC)was calculated.Results The patients' ROC value ofΔHR,ΔSBP and ΔPD responding to NRS variation were AUCΔPD 0.904 (95% CI 0.822-0.987 ), AUCΔSBP 0.65 1(95%CI 0.5 10-0.781)and AUCΔHR 0.588(95%CI 0.444-0.733)respectively.Value of AUCΔPD was larger than that of AUCΔSBP and AUCΔHR respectively (P < 0.05 ).Importantly, operating characteristic curve (ROC)analysis showed that the diagnostic cutoff value of ΔPD was 41.3% with a sensitivity of 80.0% and a specificity of 93.5% and the diagnostic cutoff value of ΔSBP was 10.3% with a sensitivity of 62.4% and a specificity of 71.5%.Conclusion This study demon-strated that the accuracy of ΔPD was higher than ΔSBP and ΔHR responding to pain/analgesia evalu-ation.ΔPD was a valuable index for assessment of postoperative pain.