Introduction

Body temperature is one of the vital signs. Hypothermia, defined as a core temperature below 36°C, is a common surgical complication [1].

Cesarean delivery, as a method to resolve dystocia and maternal/neonatal complications, is widely recognized for its safety. Surveys indicate [2] that the cesarean delivery rate in China is as high as 46.2%. Women undergoing cesarean delivery constitute a specific surgical population and are also a high-risk group for intraoperative hypothermia, with an incidence ranging from 38% to 75% [3].

Intraoperative hypothermia during cesarean delivery may increase the incidence of perioperative complications and surgical site infections, cause coagulation disorders, prolong the duration of anesthetic drug effects, and reduce pituitary prolactin secretion. Decreased prolactin levels can negatively impact breastfeeding for the newborn, increasing neonatal morbidity and mortality [1, 4].

This article reviews the risk factors, prevention, and management strategies for intraoperative hypothermia in cesarean delivery patients, aiming to reduce its occurrence and ensure the safety of both mother and child.

I. Risk Factors for Hypothermia in Cesarean Delivery Patients

1. Maternal Factors

These primarily include the patient's vital signs upon entering the operating room, BMI, fasting duration, and certain coexisting obstetric conditions. Furthermore, emergency cesarean deliveries typically require 4-6 hours of fasting, which reduces the mother's energy reserves, increases cold sensitivity, and predisposes her to intraoperative hypothermia [5].

2.Surgical Factors

The relatively low ambient temperature of the operating room, combined with skin exposure and disinfection during surgery, promotes increased heat loss from the mother's body, leading to a drop in temperature. Additionally, factors such as the opening of the abdominal and uterine cavities, delivery of the fetus and placenta, significant loss of amniotic fluid, and intrapartum hemorrhage carry away substantial heat from the mother, further lowering her body temperature.

Moreover, routine intravenous fluid administration during cesarean surgery, and blood transfusion in special circumstances, contribute to hypothermia. Infusing 1 liter of room-temperature fluid or 1 unit of 5°C stored blood can decrease core temperature by 0.25–0.50°C in adults [6].

3. Anesthesia

Anesthesia is a significant factor contributing to intraoperative hypothermia in cesarean patients. Anesthesia duration, technique, and drugs used can all lead to hypothermia. Considering maternal and fetal safety, neuraxial anesthesia (spinal/epidural) is predominantly used for cesarean deliveries in China, with general or local infiltration anesthesia reserved for special cases.

Under neuraxial anesthesia, heat loss occurs via two main mechanisms within the first hour: vasodilation below the level of the block leading to heat loss, followed by core-to-peripheral heat redistribution [7]. Neuraxial anesthesia can also cause vasoconstriction above the block level and lower the shivering threshold (by approximately 0.5°C), although this vasoconstriction does not prevent core temperature decline [8].

Furthermore, muscle relaxants are often used during cesarean sections to optimize surgical exposure. This reduces muscle activity and consequently the body's heat production, leading to a further drop in the mother's temperature.

4.Healthcare Personnel

Currently, there is insufficient awareness among medical staff regarding the importance of maintaining normothermia during cesarean delivery, and the harms of intraoperative hypothermia are not given adequate attention. The implementation of perioperative temperature protection measures needs strengthening [8]. A European study of 8083 surgical patients found that only 19.4% had intraoperative temperature monitoring records [9]. A domestic survey on intraoperative warming practices found that the rate of active temperature protection for parturients was only 18.4%, the lowest among surveyed patient groups [10].

II. Measures to Prevent Hypothermia in Cesarean Delivery Patients

1.Temperature Monitoring

As a vital sign, body temperature is a simple, easily measurable parameter, yet it is often overlooked. Continuous intraoperative temperature monitoring provides a direct, dynamic reflection of the patient's thermal status. Using this objective data allows for the rational deployment of adjunctive equipment to prevent intraoperative hypothermia [3].

2. Anesthesia

Researchers have conducted in-depth studies on anesthesia techniques and medications to minimize their impact on maternal temperature. Clinical comparisons have shown [12] that spinal anesthesia causes greater impairment of maternal thermoregulation compared to epidural anesthesia. Another study [13] found that intrathecal injection of 2.5 μg sufentanil combined with bupivacaine and morphine significantly reduced the incidence of intraoperative hypothermia in cesarean patients, with no adverse effects on the newborn.

3. Warming Management

Appropriate intraoperative warming can reduce the incidence of hypothermia in parturients without affecting intraoperative blood loss or neonatal Apgar scores [14]. Intraoperative warming is divided into passive warming and active warming. As previous articles have emphasized the difference between these two and the advantages of active warming, this section will focus on active warming.

Currently, the two main active warming methods used internationally are forced-air warming and fluid warming. Forced-air warming increases skin temperature primarily through conduction and convection at the periphery, while fluid warming increases skin temperature through peripheral and central conduction, related to the rapid distribution of warmed fluid throughout the body via blood flow [15]. Both methods can achieve ideal perioperative warming effects for patients.

In addition, preoperative visits and intraoperative humanistic care, such as providing relevant health education and inquiring about patient comfort, can effectively alleviate the mother's anxieties regarding the surgery, anesthesia, pain, and fetal well-being. Adjusting the mother's psychological state can help lower the incidence of intraoperative hypothermia [16].

III. Conclusion

In summary, active warming can reduce the incidence of hypothermia in cesarean delivery patients, promote physical comfort, and contribute to successful surgery and postoperative recovery for the mother.

Furthermore, there is a need to improve the intraoperative temperature management skills of operating room staff through targeted training and standardized protocols. Establishing standardized operating procedures and emergency plans for preventing intraoperative hypothermia during cesarean delivery, along with the provision and proper use of warming equipment, is essential for comprehensively addressing maternal temperature management and ensuring perioperative safety for both mother and child.

References

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