Pulse perfusion index for predicting intrapartum fever during epidural analgesia

To assess whether pulse perfusion index (PI) values could be employed to predict intrapartum fever and to provide a cut-off PI value for predicting intrapartum fever occurrence. We conducted a single-center, prospective, observational study. Delivery room at the Department of Obstetrics, Affiliated Hospital of Jiangsu University. 117 parturients who intended to have a vaginal delivery. Each parturient received epidural analgesia. We checked each parturient's tympanic temperature before analgesia (T0), at 1 h (T1) and 2 h (T2) after analgesia, immediately at the end of the second (T3) and third (T4) stages of labor, and at 1 h postpartum (T5). A temperature of ≥38°C was defined as fever. PI, measured on the right second toe, was recorded before analgesia (PI0) and at 10 min (PI10), 20 min (PI20), and 30 min (PI30) after analgesia. The PI change rate was calculated as the incremental change in PI30 from PI0, divided by the PI0. Receiver operating characteristic (ROC) curves were used to verify the utility of the PI30 and PI change rate values for predicting intrapartum fever. We found that peak temperature (TP) occurred at the end of the second or the third stage of labor. Within 30 min after analgesia, the PI showed a significant increase over time and there was a linear correlation between PI30 and TP values (P < 0.001, r = 0.544). The PI10, PI20, PI30 and PI change rate in febrile parturients were higher than those in afebrile parturients (P < 0.001). The area under the ROC (AUROC) for PI30 was 0.818 (P < 0.001) with a cut-off of 9.30. The AUROC of the PI change rate was 0.738 (P < 0.001) with a cut-off of 3.45. PI30 and PI change rate values could be used to predict intrapartum fever in parturients after epidural analgesia.