Correlation between the Perfusion Index and Intraoperative Hypothermia: A Prospective Observational Pilot Study

Abstract

Background and Objectives: We examined the association between the baseline perfusion index (PI) and changes in intraoperative body temperature during general anesthesia. The PI reflects the peripheral perfusion state. The PI may be associated with changes in body temperature during general anesthesia because the degree of redistribution of body heat from the central to the peripheral compartment varies depending on the peripheral perfusion state. Materials and Methods: Thirty-eight patients who underwent brain surgery were enrolled in this study. The baseline PI and body temperature of the patients were measured on entering the operating room. Body temperature was recorded every 15 min after induction of anesthesia using an esophageal temperature probe. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for intraoperative hypothermia. Results: Eighteen patients (47 %) developed hypothermia intraoperatively. The baseline PI was significantly lower among patients in the hypothermia group (1.8 ± 0.7) than among those in the normothermia group (3.0 ± 1.2) (P < 0.001). The baseline PI and body temperature were independently associated with intraoperative hypothermia (PI: odds ratio [OR], 0.270; 95% confidence interval [CI], 0.105 - 0.697; P = 0.007, baseline body temperature: OR, 0.061; 95% CI, 0.005–0.743; P = 0.028). Conclusions: This study showed that low baseline PI was the factor most related to the development of intraoperative hypothermia. Future studies should consider the PI as a predictor of intraoperative hypothermia.

Relationship between perfusion index and central temperature before and after induction of anesthesia in laparoscopic gastrointestinal surgery: a prospective cohort study

“…The PI before and after induction of anesthesia showed signi cant correlations with central temperature decrease and peripheral temperature increase, which supported the study hypothesis. This is consistent with previous reports, which state that the PI was associated with central temperature and correlated with intraoperative peripheral temperature and the peripheral-central temperature gradient during cesarean section [9,[15][16][17]. Thus, it may be possible to estimate and prevent redistribution hypothermia at 30 and 60 min after anesthesia induction by managing the body temperature according to the baseline PI before and PI ratio of variation at 30 min before and after anesthesia induction, respectively, as indices.…”

“…A pulse oximeter is a widely used, non-invasive medical device used in perioperative management that measures oxygen saturation and can simultaneously measure the perfusion index (PI)-the ratio between pulsatile and non-pulsatile blood volume. PI changes measured in the upper limbs are reportedly closely correlated with hemodynamics under general anesthesia [9]. PI is a useful tool for monitoring changes in peripheral perfusion due to anesthesia in real time.…”

“…In addition, changes in PI are useful for determining the effects of body temperature redistribution, vasodilation, and association with anesthesia. Previous prospective pilot studies have shown that patients with low PI before the induction of general anesthesia are more likely to develop intraoperative hypothermia [9][10]. However, the before anesthesia induction cut-off PI and ratio after anesthesia induction of PI variation that is effective in preventing redistribution hypothermia have not currently been clari ed.…”

Association between preoperative toe perfusion index and maternal core temperature decrease during cesarean delivery under spinal anesthesia: a prospective cohort study

“…Therefore, patients with low peripheral PI have a greater redistribution of body temperature after the induction of anesthesia due to low peripheral temperature, resulting in core temperature decrease. Some researchers reported that low baseline peripheral PI was the most relevant factor in the development of intraoperative hypothermia under general anesthesia [ 17 ]. Their study results are similar to our findings that low preoperative toe PI can be a risk for intraoperative hypothermia in parturients undergoing cesarean delivery under spinal anesthesia.…”

“…Although these gradients have been used as a measure of peripheral vasoconstriction [ 13 ], temperature gradients before the induction of anesthesia affect the magnitude of body heat redistribution by vasodilation following anesthetic administration [ 14 – 16 ]. A prospective observational pilot study demonstrated that low baseline peripheral PI was the most relevant factor for the development of intraoperative hypothermia under general anesthesia [ 17 ]; therefore, this suggests that preoperative peripheral PI may be useful in predicting the magnitude of redistributive hypothermia. To our knowledge, no previous reports have investigated the association between baseline peripheral PI and body temperature decrease during cesarean delivery under spinal anesthesia.…”