Breakthrough Study Reveals Critical Risk Factors for Intraoperative Hypothermia in Surgical Patients

Can Intraoperative Hypothermia Insights Transform Surgical Outcomes?

In a groundbreaking multicenter prospective study spanning 12 tertiary hospitals across China, researchers have uncovered significant insights into intraoperative hypothermia among adult surgical patients. The investigation, which included over 4,500 patients, revealed that nearly one in four surgical patients (23.82%) experienced intraoperative hypothermia, defined as a core body temperature below 36.0°C. This large-scale clinical research effort represents one of the most comprehensive examinations of hypothermia risk factors in a Chinese population and provides valuable evidence for improving perioperative temperature management strategies. The findings, collected between November 2024 and February 2025, highlight the complex interplay of patient characteristics and procedural factors that influence thermal regulation during surgery, offering clinicians practical guidance for identifying high-risk individuals and implementing targeted preventive measures.

Are There Specialty-Specific Patterns in Hypothermia Incidence?

The study meticulously documented core temperature measurements across diverse surgical specialties, revealing striking variations in hypothermia incidence. Hand surgery (51.35%), emergency surgery (44.44%), and cardiovascular surgery (40.07%) demonstrated the highest rates of intraoperative hypothermia, while otorhinolaryngology (13.92%) and obstetrics/gynecology (16.24%) showed significantly lower incidences. These specialty-specific differences underscore the importance of tailored temperature management approaches rather than one-size-fits-all protocols. Notably, the research identified preoperative baseline temperature as a powerful predictor of intraoperative thermal instability. Patients with a baseline core temperature ≤35.9°C exhibited an alarming 85.93% incidence of intraoperative hypothermia, compared to just 21.91% in those with normal baseline temperatures ≥36.0°C. This finding suggests that routine preoperative temperature screening could serve as a simple yet effective risk stratification tool, allowing for early intervention in vulnerable patients. Age-related patterns were equally compelling, with hypothermia rates rising steadily from 16.74% in young adults (18-27 years) to 34.83% in elderly patients (78-87 years), reflecting the progressive decline in thermoregulatory capacity with advancing age.

Through rigorous statistical analysis, the research team identified five independent risk factors significantly associated with intraoperative hypothermia. Higher ASA classification (OR = 1.408, 95% CI: 1.197-1.657), indicating poorer overall physiological reserve, emerged as a key predictor. Surgical approach proved influential, with open surgeries conferring greater risk compared to minimally invasive or superficial procedures (OR = 0.735, 95% CI: 0.577-0.936 for less invasive approaches). The extent of skin disinfection and exposure substantially impacted thermal stability, with procedures involving the extremities, thorax, abdomen, or back associated with doubled odds of hypothermia (OR = 2.024, 95% CI: 1.534-2.670) compared to head and neck surgeries. Volume of cold intravenous fluid administration showed a dose-dependent relationship with hypothermia risk (OR = 1.365, 95% CI: 1.140-1.633), highlighting the thermal burden imposed by unwarmed fluids. Perhaps most predictably, longer surgical duration emerged as a powerful independent risk factor (OR = 2.014, 95% CI: 1.683-2.411), reflecting cumulative heat loss during extended procedures. Interestingly, while anesthesia type, intraoperative blood transfusion, and blood loss showed significant associations in univariate analysis, they did not remain independent predictors after adjustment for other variables, suggesting their effects may be mediated through more proximal factors such as surgical complexity and duration.

What Warming Strategies Work Best in the OR?

The research also yielded valuable insights regarding warming interventions in routine clinical practice. By tracking intraoperative temperature trajectories under three common warming approaches – passive insulation (n = 2,436), forced-air warming (n = 1,526), and resistive heating (n = 554) – the study documented differential patterns of thermal regulation. All groups exhibited similar baseline temperatures (36.35-36.40°C) at the start of surgery, but diverged significantly thereafter. Patients receiving only passive insulation showed the most pronounced temperature decline during the initial 210 minutes of surgery, with some approaching the hypothermia threshold. In contrast, both active warming groups maintained higher core temperatures throughout the procedure. The resistive heating group demonstrated particularly effective temperature recovery in later surgical phases (330-420 minutes), eventually surpassing the forced-air warming group. While these observations provide valuable real-world data on warming practices, the researchers appropriately acknowledge that intervention selection was not randomized but reflected clinical judgment based on patient and procedural characteristics. Nevertheless, the findings align with existing evidence supporting the superiority of active warming strategies over passive measures for maintaining intraoperative normothermia.

Could Study Design and Limitations Affect Future Protocols?

The comprehensive nature of this multicenter investigation addresses several limitations of previous studies, which were predominantly single-center, retrospective, and limited in sample size. By implementing standardized protocols across geographically diverse hospitals, the researchers enhanced the generalizability of their findings while minimizing regional bias. The prospective design allowed for systematic data collection and rigorous quality control measures, including standardized temperature monitoring techniques and unified risk assessment tools. However, the authors acknowledge certain limitations, including potential variations in perioperative temperature management practices among participating hospitals and the observational nature of the study, which precludes definitive causal inferences. Additionally, while the study focused on intraoperative hypothermia, it did not assess long-term clinical outcomes or postoperative temperature fluctuations, areas that warrant further investigation. Despite these constraints, the research provides compelling evidence to guide clinical decision-making and resource allocation in perioperative thermal management.

Will These Findings Shape Tomorrow's Surgical Best Practices?

These findings have significant implications for perioperative practice across diverse clinical settings. For anesthesiologists and surgeons, they underscore the importance of comprehensive preoperative risk assessment that considers not only baseline temperature but also patient demographics, comorbidities, and planned procedural characteristics. For hospitals and healthcare systems, the results highlight the value of implementing standardized protocols for temperature monitoring and active warming interventions, particularly for high-risk specialties and vulnerable patient populations. The marked variation in hypothermia incidence across surgical specialties suggests that resource allocation should be prioritized accordingly, with enhanced vigilance in hand surgery, emergency procedures, and cardiovascular operations. Looking forward, these findings raise important questions for future research: How can preoperative temperature screening be most effectively integrated into routine clinical workflows? What combination of warming strategies provides optimal thermal protection for different risk profiles? And how do regional variations in practice patterns influence temperature management outcomes across diverse healthcare settings?

In conclusion, this landmark multicenter study provides robust evidence regarding the incidence, characteristics, and risk factors of intraoperative hypothermia in adult surgical patients across China. By identifying patient subgroups at heightened risk and clarifying the relative importance of various perioperative factors, the research offers a foundation for developing more precise risk prediction tools and implementing targeted temperature management strategies. As healthcare systems worldwide strive to enhance perioperative safety and optimize resource utilization, these findings offer valuable guidance for clinicians seeking to protect patients from the well-documented adverse consequences of intraoperative hypothermia. Could the integration of these risk factors into automated electronic health record systems enable more personalized and proactive temperature management in the future? And might the regional variations observed in this Chinese population differ from patterns in other countries with different healthcare infrastructures and surgical practices?

Summary

A comprehensive multicenter study conducted across 12 tertiary hospitals in China involving over 4,500 adult surgical patients has revealed that nearly one in four patients (23.82%) experience intraoperative hypothermia, defined as core body temperature below 36.0°C. The research identified significant variations in hypothermia incidence across surgical specialties, with hand surgery (51.35%), emergency surgery (44.44%), and cardiovascular surgery (40.07%) showing the highest rates. Five independent risk factors were identified: higher ASA classification, open surgical approach, extensive skin disinfection and exposure areas, volume of cold intravenous fluid administration, and longer surgical duration. Patients with preoperative baseline temperatures of 35.9°C or lower exhibited an 85.93% incidence of intraoperative hypothermia, suggesting routine preoperative temperature screening could serve as an effective risk stratification tool. The study also documented that active warming strategies, particularly resistive heating and forced-air warming, proved superior to passive insulation in maintaining normothermia throughout surgical procedures. These findings provide valuable evidence for developing targeted temperature management protocols, particularly for high-risk specialties and vulnerable patient populations including elderly patients, who demonstrated hypothermia rates reaching 34.83% in the 78-87 age group compared to 16.74% in young adults.