Via Research Recognition Day 2024 VCOM-Carolinas

Educational Reports

A Quantitative Investigation of Intraoperative Hypothermia as an Independent Risk Factor for Postpartum Hemorrhage and Surgical Site Infection Following Cesarean Delivery Jordan Winebrenner, OMS-III; Rebecca Dudley, OMS-III; Kristine Lombardozzi, MD; Robert Steed, MBA Spartanburg Regional Health System - Spartanburg, SC

Hypothermia Protocol

Quality Improvement

Introduction & Background

There is a growing body of research indicating that patients who experience hypothermia during surgery may be at an increased risk of coagulopathies and surgical site infections (SSIs). However, little is known about the potential consequences of maternal hypothermia during cesarean section. Postpartum hemorrhage (PPH), a significant contributor to maternal mortality, has been linked to coagulopathy in many patients. In addition, surgical site infections are a common complication following cesarean section. Given the global rise in cesarean section rates, it is crucial for surgical teams to adopt evidence-based techniques and understand the risk factors that contribute to maternal morbidity and mortality. Spinal anesthesia is the most commonly used anesthesia during cesarean section and has been shown to lower core body temperatures. This study aims to elucidate whether hypothermia during cesarean section with spinal anesthesia is associated with an increased risk of postpartum complications, such as hemorrhage and surgical site infections. Against this backdrop, a preliminary quality improvement study conducted in the Fall of 2022 revealed elevated rates of hypothermia during trauma cases at Spartanburg Regional Health System (SRHS) affiliated hospitals. Three out of the four hospitals exceeded the nationally accepted benchmark 7 of 15% for hypothermia rates upon analyzing anesthesia records. In response to these findings, a hypothermia protocol was devised for the SRHS’s Trauma ACS Department. This preliminary data was hypothesis-generating and laid the groundwork for the present study, expanding its focus to evaluate hypothermia during cesarean sections within SRHS's labor and delivery ward. This ongoing study is a single-center, retrospective trial that focuses on patients who were admitted to Spartanburg Regional Hospital System (SRHS) and underwent cesarean section delivery. Laboring patients (18-40 years of age) with a singleton pregnancy who had a non-emergent cesarean section with spinal anesthesia from the 1/1/22-12/31/22 calendar year were included. Laboring patients outside of the outlined age range, emergent deliveries, and patients who did not receive spinal anesthesia were excluded. Data gathering was done by chart review. Normally distributed continuous data will be analyzed using a two sample T test. Non-parametric continuous data will be analyzed using a Wilcoxon Rank Sum Test. Discrete/ordinal data with a normal distribution will be analyzed using a Pearson Correlation Coefficient. Non-parametric discrete/ordinal data will be analyzed using Spearman Correlation. Categorical data will be evaluated using Chi-Square or Fisher’s Exact Test. The primary outcome is postoperative rates of postpartum hemorrhage (defined as estimated blood loss or EBL >1000mL) and surgical site infection. Secondary outcomes of the study will include chorioamnionitis rates. Data included: demographics, gravida para score, fetal gestation, date of admission, discharge date, number of days spent in the labor and delivery unit, quantitative blood loss during delivery, preoperative temperatures, intraoperative temperatures, and postoperative temperatures. Research Design & Methods

During our study, a notable observation emerged – a considerable number of charts lacked documented preoperative temperatures. Simultaneously, we noted discrepancies in postpartum hemorrhage diagnoses, as they did not consistently align with estimated blood loss. Furthermore, charts featuring estimated blood losses meeting the criteria for a postpartum hemorrhage diagnosis did not consistently include an ICD-10 code for postpartum hemorrhage. These observations prompted us to conduct a meticulous examination of these factors, aiming to pinpoint areas for improvement and enhance our understanding of the diverse factors contributing to intraoperative hypothermia and postpartum hemorrhage outcomes.

Table 2. This table details the incidence of undocumented preoperative and intraoperative temperatures in the anesthesia records. Nearly half of the 277 encounters did not have a pre-operative temperature documented, and over 5% of encounters did not have any intraoperative temperatures documented. Further data analysis will be done in the future to determine if these amounts are clinically significant.

Figure 1. This figure depicts the hypothermia protocol developed during the preliminary hypothermia study for potential use in SRHS's Trauma ACS Department.

Table 3. This table breaks down the encounters that received an official ICD-10 code for the diagnosis of postpartum hemorrhage with the encounters that met the criteria of postpartum hemorrhage based on an EBL >1000 ml. Only two encounters that had an EBL >1000 ml received the diagnosis of PPH, Meanwhile, two-thirds of the encounters that did receive a diagnosis of PPH, did not meet the criteria for PPH based on EBL.

Results

Conclusions

The connection between chorioamnionitis and surgical site infections in conjunction with intraoperative hypothermia remains elusive, given the absence of any occurrences of these events within our sample size. The findings of this study may shed light on a potential correlation between intraoperative hypothermia and the occurrence of postpartum hemorrhage and surgical site infection. Beyond the pursuit of statistical significance, this study will act as a quality improvement initiative for SRHS's labor and delivery ward, contributing to the ongoing enhancement of patient care and outcomes. The authors of this poster extend their sincere gratitude to Thomas Mack of Spartanburg Health System for his invaluable contributions to our data acquisition, enriching the content of this work. We also express our heartfelt thanks to the Spartanburg Regional Healthcare System Institutional Review Board (IRB) for their prompt and thorough review, leading to the official acceptance of the project on September 26th, 2023 (Project 2103812-3).Additionally, we extend our acknowledgment to the laboring mothers without whom this project would not have been possible. Acknowledgements

Table 1. The incidence of hypothermia, postpartum hemorrhage, and surgical site infection in the 277 qualifying patient encounters compared to nationally accepted reasonable benchmarks 4,5,7 .

Results: A total of 277 encounters met the criteria for this study. Of these 277 encounters, the incidence of hypothermia and surgical site infections were found to be lower than the reasonable benchmark. However, the incidence of postpartum hemorrhage was found to be above the national average. This study is currently still in progress; therefore, the statistical analyses have not yet been finalized. After completion of the study, the results will reveal if there is a statistically significant relationship between hypothermia and the incidence of postpartum hemorrhage and surgical site infection.

References

91

2024 Research Recognition Day