Development and validation of an intraoperative hypothermia nomograph model for patients undergoing video-assisted thoracoscopic lobectomy: a retrospective study.

This study aimed to develop and internally validate a nomogram model for assessing the risk of intraoperative hypothermia in patients undergoing video-assisted thoracoscopic (VATS) lobectomy. This study is a retrospective study. A total of 530 patients who undergoing VATS lobectomy from January 2022 to December 2023 in a tertiary hospital in Wuhan were selected. Patients were divided into hypothermia group (n = 346) and non-hypothermia group (n = 184) according to whether hypothermia occurred during the operation. Lasso regression was used to screen the independent variables. Logistic regression was used to analyze the risk factors of hypothermia during operation, and a nomogram model was established. Bootstrap method was used to internally verify the nomogram model. Receiver operating characteristic (ROC) curve was used to evaluate the discrimination of the model. Calibration curve and Hosmer Lemeshow test were used to evaluate the accuracy of the model. Decision curve analysis (DCA) was used to evaluate the clinical utility of the model. Intraoperative hypothermia occurred in 346 of 530 patients undergoing VATS lobectomy (65.28%). Logistic regression analysis showed that age, serum total bilirubin, inhaled desflurane, anesthesia duration, intraoperative infusion volume, intraoperative blood loss and body mass index were risk factors for intraoperative hypothermia in patients undergoing VATS lobectomy (P < 0.05). The area under ROC curve was 0.757, 95% CI (0.714-0.799). The optimal cutoff value was 0.635, the sensitivity was 0.717, and the specificity was 0.658. These results suggested that the model was well discriminated. Calibration curve has shown that the actual values are generally in agreement with the predicted values. Hosmer-Lemeshow test showed that χ2 = 5.588, P = 0.693, indicating that the model has a good accuracy. The DCA results confirmed that the model had high clinical utility. The nomogram model constructed in this study showed good discrimination, accuracy and clinical utility in predicting patients with intraoperative hypothermia, which can provide reference for medical staff to screen high-risk of intraoperative hypothermia in patients undergoing VATS lobectomy.

[Association between intraoperative hypothermia and outcomes in neonatal patients undergoing non-cardiac surgery].

Objective: To investigate the impact of intraoperative hypothermia on postoperative outcome in neonatal patients undergoing non-cardiac surgery. Methods: The data of 1 008 neonates undergoing non-cardiac surgery in Children's Hospital, Zhejiang University School of Medicine from January 2020 to October 2022 were retrospectively collected,which included 558 males and 450 females, with a midian age [M (Q1, Q3)] of 6 (2, 14) days. Neonates were divided into 4 groups according to whether hypothermia (below 36 ℃) occurred and the lowest body temperature during the surgery: normal temperature group (n=246), mild hypothermia group (the lowest temperature ranged 35.0-35.9 ℃, n=434), moderate hypothermia group (the lowest temperature ranged 34.0-34.9 ℃, n=232) and severe hypothermia group (the lowest temperature<34 ℃, n=96). The primary outcome was the incidence of intraoperative hypothermia. The four groups' difference of postoperative hospital stay, postoperative mortality within 30 days, postoperative pulmonary complications, postoperative hemorrhage/blood transfusion and acidosis were compared. Multivariate logistic regression was used to analyze the relationship between intraoperative hypothermia and prolonged postoperative hospital stay (>14 d), 30 d-mortality and other complications. Results: In the 1 008 neonatal patients, 762 (75.6%) cases suffered intraoperative hypothermia, among which the incidence of mild, moderate and severe hypothermia was 43.1% (434/1008), 23.0% (232/1008) and 9.5% (96/1008), respectively. The postoperative hospital stay in normal, mild, moderate and severe hypothermia groups was 9.0 (5.8, 18.0), 12.0 (7.0, 21.0), 17.0 (10.0, 34.5) and 31.5 (12.5, 55.8) days. The mortality rate with 30 days after surgery was 2.9% (7/246), 4.4% (19/434), 6.9% (16/232) and 14.7% (14/96), the incidence of postoperative pulmonary complications was 31.7%(78/246), 39.9%(173/434), 44.8%(104/232) and 67.4%(64/96), the rate of postoperative hemorrhage/blood transfusion was 19.9%(49/246), 32.3%(140/434), 49.1%(114/232) and 79.0%(75/96), and the incidence of acidosis was 26.8%(66/246), 35.7%(155/434), 44.4%(103/232) and 46.3%(44/96), respectively. All differences were statistically significant (all P<0.05). According to the adjusted logistic regression analysis, compared with the normal body temperature group, severe hypothermia was associated with prolonged postoperative hospital stay (OR=1.962, 95%CI: 1.063-3.619) and postoperative pulmonary complications (OR=2.020, 95%CI: 1.149-3.553). The mild, moderate and severe hypothermia group could increase the risk of postoperative blood/transfusion rate (mild: OR=1.690, 95%CI: 1.080-2.644; Moderate: OR=2.382, 95%CI: 1.444-3.927; Severe: OR=8.334, 95%CI: 3.123-8.929). The mild and moderate hypothermia could raise the risk of acidosis (mild: OR=1.458, 95%CI: 1.009-2.107; Moderate: OR=1.949, 95%CI: 1.279-2.972). Conclusion: Intraoperative hypothermia can prolong the postoperative hospital stay, and increase the risk of postoperative mortality, postoperative pulmonary complications, postoperative hemorrhage/transfusion, and acidosis.

Hybrid operating rooms and the risk of postoperative hypothermia in pregnant women with placenta previa: A retrospective cohort study.

BACKGROUND: Births at advanced maternal ages (≥ 35 years) are increasing. This has been associated with a higher incidence of placenta previa, which increases bleeding risk. Hybrid operating rooms, designed to accommodate interventions and cesarean sections, are becoming more prominent because of their dual capabilities and benefits. However, they have been associated with increased postoperative hypothermia in pediatric settings; moreover, this has not been studied in pregnant women with placenta previa. METHODS: This retrospective cohort study included pregnant women diagnosed with placenta previa who underwent elective cesarean section under general anesthesia between May 2019 and 2023. The patients were categorized according to the operating room type. The primary outcome was to determine whether the hybrid operating room is a risk factor for immediate postoperative hypothermia, defined as a tympanic membrane temperature below 36.0°C. The secondary outcomes were the effects of immediate postoperative hypothermia on the durations of postanesthetic care unit and postoperative hospital stays and incidence of complications. RESULTS: Immediate postoperative hypothermia (tympanic membrane temperature < 36.0°C) was more prevalent in the hybrid than in the standard operating room group (20% vs. 36.6%, p = 0.033), with a relative risk of 2.86 (95% confidence interval 1.24-6.64, p < 0.001). Patients undergoing surgery in the hybrid operating room who experienced immediate postoperative hypothermia stayed longer in the postanesthetic care unit (26 min vs. 40 min, p < 0.001) and in the hospital after surgery (4 days; range 3-5 vs. 4 days; range 4-11, p = 0.021). However, the complication rates of both groups were not significantly different (11.3% vs 7.3%, p = 0.743). CONCLUSION: Hybrid operating rooms may increase the risk of postoperative hypothermia. Postoperative hypothermia is associated with prolonged postanesthetic care unit and hospital stays. Preventing hypothermia in patients in hybrid operating rooms is of utmost importance.

Normal range and risk factors for deviating body temperatures during the first 24 hours in term-born infants under standardised care: an observational study.

OBJECTIVE: Body temperature for a known ambient temperature is not known for infants born at term. We aimed to determine the normal range and the incidences of hypothermia and hyperthermia during the first 24 hours of life in healthy term-born infants nursed according to WHO recommendations. DESIGN: Prospective observational study. SETTING: Norwegian single centre district hospital. Infants were observed during skin-to-skin care or when dressed in cots. PARTICIPANTS: Convenience sample of 951 healthy infants born at term. METHODS: Delivery room temperature was aimed at 26-30°C and rooming-in temperature at 24°C. We measured rectal and room temperatures at 2, 4, 8, 16 and 24 hours of age. MAIN OUTCOME MEASURES: Percentile curves for rectal temperature. Proportions and risk factors for hypothermia and hyperthermia. RESULTS: The mean (SD) room temperature was 24.0°C (1.1), 23.8°C (1.0), 23.8°C (1.0)., 23.7°C (0.9) and 23.8°C (0.9). The median (2.5, 97.5 percentile) rectal temperature was 36.9°C (35.7-37.9), 36.8°C (35.9-37.5), 36.9°C (36.1-37.5), 37.0°C (36.4-37.7) and 37.1°C (36.5-37.7). Hypothermia (<36.5°C) occurred in 28% of the infants, 82% of incidents during the first 8 hours. Risk factors for hypothermia were low birth weight (OR 3.1 (95% CI, 2.0 to 4.6), per kg), male sex, being born at night and nursed in a cot versus skin to skin. Hyperthermia (>37.5°C) occurred in 12% and most commonly in large infants after 8 hours of life. Risk factors for hyperthermia were high birth weight (OR 2.2 (95% CI, 1.4 to 3.5), per kg), being awake, nursed skin to skin and being born through heavily stained amniotic fluid. CONCLUSIONS: Term-born infants were at risk of hypothermia during the first hours after birth even when nursed in an assumed adequate thermal environment and at risk of hyperthermia after 8 hours of age.

How three linked clinical observations led to an understanding of perioperative heat balance: A personal reflection on the scientific process.

Three linked clinical observations prompted our current understanding of perioperative heat balance. The first was the extraordinarily rapid decrease in core temperature after induction of general anesthesia which led to an understanding of redistribution hypothermia. The second was the linear reduction in core temperature during the subsequent 2-3 h which led to an understanding of anesthetic effects on metabolic heat production and factors that influence cutaneous heat loss. And the third was the observation that core temperature reaches a plateau at about 34.5 °C which led to the understanding that thermoregulatory vasoconstriction re-emerges when patients become sufficiently hypothermic, and that arteri-venous shunt constriction constrains metabolic heat to the core thermal compartment.

Perioperative Hypothermia in Elderly Patients During Pelvic Floor Reconstruction Surgery: An Observational Study.

INTRODUCTION AND HYPOTHESIS: The potential predictors of pelvic floor reconstruction surgery hypothermia remain unclear. This prospective cohort study was aimed at identifying these predictors and evaluating the outcomes associated with perioperative hypothermia. METHODS: Elderly patients undergoing pelvic floor reconstruction surgery were consecutively enrolled from April 2023 to September 2023. Perioperative temperature was measured at preoperative (T1), every 15 min after the start of anesthesia (T2), and 15 min postoperative (T3) using a temperature probe. Perioperative hypothermia was defined as a core temperature below 36°C at any point during the procedure. Multivariate logistic regression analysis was conducted to determine factors associated with perioperative hypothermia. RESULTS: A total of 229 patients were included in the study, with 50.7% experiencing hypothermia. Multivariate analysis revealed that the surgical method involving pelvic floor combined with laparoscopy, preoperative temperature < 36.5°C, anesthesia duration ≥ 120 min, and the high levels of anxiety were significantly associated with perioperative hypothermia. The predictive value of the multivariate model was 0.767 (95% CI, 0.706 to 0.828). CONCLUSIONS: This observational prospective study identified several predictive factors for perioperative hypothermia in elderly patients during pelvic floor reconstruction surgery. Strategies aimed at preventing perioperative hypothermia should target these factors. Further studies are required to assess the effectiveness of these strategies, specifically in elderly patients undergoing pelvic floor reconstruction surgery.

Postoperative hypothermia is associated with reduced length of stay in adult acute burn survivors.

BACKGROUND: The hypermetabolic response after a burn predisposes patients to hypothermia due to dysfunction of thermoregulation. Traditionally, hypothermia is avoided actively in burn care due to reported complications associated with low body temperature. The likelihood of hypothermia with acute burn surgery is compounded by general anesthesia, exposure of wound areas and prolonged operation times. However, we find limited studies exploring the effects of perioperative hypothermia on length of stay in the adult burn population. OBJECTIVE: To determine associations between postoperative hypothermia and hospital length of stay in adult burns patients. METHOD: This retrospective cohort study involved patients admitted to the State Adult Burn Unit in Western Australia between 1st January 2015 to 28th February 2021. All adults who underwent surgery for acute burn, and had postoperative recovery room body temperature recorded, were included in the study. In this study, we defined normothermia as >36.5C and hypothermia as < 36.0 °C with mild, moderate, and severe hypothermia being 35.0-35.9 °C, 34.0-34.9 °C and < 34.0 °C, respectively. Patients with hyperthermia were excluded. Multivariable general linear models explored if hypothermia was independently associated with length of stay. RESULTS: Among 1486 adult patients, 1338 (90%) were normothermic postoperatively, with temperatures >36.0C. We included 148 (10%) patients with hypothermia (temperature <36.0 °C) postoperatively. Most burns in the study population were minor: 96% had burns < 15% TBSA. Data modelling demonstrated that hypothermia was associated with a shorter length of hospital stay (coefficient = -0.129, p = 0.041). CONCLUSION: In adult acute burn patients, postoperative hypothermia was associated with reduced length of stay after surgery. The positive results of this study indicate that a review of the core temperature targets with acute burn surgery, and timing of burn patient cooling practices in general is warranted.

The Effect of Brief Warming during Induction of General Anesthesia and Warmed Intravenous Fluid on Intraoperative Hypothermia in Patients Undergoing Urologic Surgery.

Background and Objectives: Transurethral urologic surgeries frequently lead to hypothermia due to bladder irrigation. Prewarming in the preoperative holding area can reduce the risk of hypothermia but disrupts surgical workflow, preventing it from being of practical use. This study explored whether early intraoperative warming during induction of anesthesia, known as peri-induction warming, using a forced-air warming device combined with warmed intravenous fluid could prevent intraoperative hypothermia. Materials and Methods: Fifty patients scheduled for transurethral resection of the bladder (TURB) or prostate (TURP) were enrolled and were randomly allocated to either the peri-induction warming or control group. The peri-induction warming group underwent whole-body warming during anesthesia induction using a forced-air warming device and was administered warmed intravenous fluid during surgery. In contrast, the control group was covered with a cotton blanket during anesthesia induction and received room-temperature intravenous fluid during surgery. Core temperature was measured upon entrance to the operating room (T0), immediately after induction of anesthesia (T1), and in 10 min intervals until the end of the operation (Tend). The incidence of intraoperative hypothermia, change in core temperature (T0-Tend), core temperature drop rate (T0-Tend/[duration of anesthesia]), postoperative shivering, and postoperative thermal comfort were assessed. Results: The incidence of intraoperative hypothermia did not differ significantly between the two groups. However, the peri-induction warming group exhibited significantly less change in core temperature (0.61 ± 0.3 °C vs. 0.93 ± 0.4 °C, p = 0.002) and a slower core temperature drop rate (0.009 ± 0.005 °C/min vs. 0.013 ± 0.004 °C/min, p = 0.013) than the control group. The peri-induction warming group also reported higher thermal comfort scores (p = 0.041) and less need for postoperative warming (p = 0.034) compared to the control group. Conclusions: Brief peri-induction warming combined with warmed intravenous fluid was insufficient to prevent intraoperative hypothermia in patients undergoing urologic surgery. However, it improved patient thermal comfort and mitigated the absolute amount and rate of temperature drop.

Effects of an early transfer from incubator to a warming crib in very low birthweight preterm infants.

PURPOSE: Very low birth weight infants are cared for postnatally in the incubator because of adverse consequences of hypothermia. Data on the optimal weight of transfer to a warming crib are rare. The aim of this study was to determine the course of temperature and body weight during a standardized transfer to a warming crib at a set weight. METHODS: Prospective intervention study in very low birthweight infants who were transferred from the incubator to a warming crib at a current weight between 1500 g and 1650 g. RESULTS: No infant had to be transferred back to an incubator. Length of hospital stay was equal compared to a historical cohort from the two years directly before the intervention. The intervention group showed an increase in the volume fed orally on the day after transfer to the warming crib, although this did not translate into an earlier discontinuation of gavage feedings. Compared to the historical group, infants in the intervention group could be transferred to an unheated crib at an earlier postmenstrual age and weight. CONCLUSIONS: Early transfer from the incubator to a warming crib between 1500 g and 1650 g is feasible and not associated with adverse short-term events or outcomes. TRIAL REGISTRATION: DRKS-IDDRKS00031832.

An integrative literature review of factors contributing to hypothermia in adults during the emergent (ebb) phase of a severe burn injury.

BACKGROUND: During the emergent (ebb) phase (first 72 h), the adult person with a severe burn experiences loss of body heat, decreased metabolism, and poor tissue perfusion putting them at risk of hypothermia, increased morbidity, and mortality. Therefore, timely and targeted care is imperative. AIM: The aim of this integrative literature review was to develop a framework of the factors contributing to hypothermia in adults with a severe burn injury during the emergent (ebb) phase. METHODS: An integrative review of research literature was undertaken as it provides an orderly process in the sourcing and evaluation of the literature. Only peer reviewed research articles, published in scholarly journals were selected for inclusion (n = 26). Research rigor and quality for each research article was determined using JBI Global appraisal tools relevant to the methodology of the selected study. FINDINGS: Contributing factors were classified under three key themes: Individual, Pre-hospital, and In-hospital factors. CONCLUSION: The structured approach enabled the development of an evidence-based framework identifying factors contributing to hypothermia in adults with a severe burn injury during the emergent (ebb) phase and adds knowledge to improve standardized care of the adult person with a severe burn injury.

Incidence and risk factors of neonatal hypothermia: A systematic review and meta-analysis.

AIM: Hypothermia poses a threat to the health and lives of newborns. Therefore, it is essential to identify the factors that influence neonatal hypothermia and provide targeted intervention suggestions for clinical practice to reduce its occurrence. METHODS: We conducted a literature search to identify factors influencing neonatal hypothermia and performed a meta-analysis to determine the prevalence of neonatal hypothermia and its associated factors. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of cohort and case-control studies, while the Agency for Healthcare Research and Quality (AHRQ) was used to evaluate the quality of cross-sectional studies. RESULTS: Eighteen studies involving 44 532 newborns from 13 countries were included. The incidence of neonatal hypothermia was 52.5% (95% CI: 0.37, 0.68). Factors such as no skin-to-skin contact, prematurity, low birth weight, delayed breastfeeding, asphyxiation and resuscitation after birth, low APGAR score, not wearing a cap, and caesarean section were found to affect neonatal hypothermia. CONCLUSION: Multiple factors influence neonatal hypothermia, and clinicians can utilise these factors to develop targeted intervention measures to prevent and reduce the incidence of neonatal hypothermia.

Impact of intraoperative hypothermia on the recovery period of anesthesia in elderly patients undergoing abdominal surgery.

BACKGROUND: This study aimed to investigate the impact of intraoperative hypothermia on the recovery period of anesthesia in elderly patients undergoing abdominal surgery. METHODS: A prospective observational study was conducted based on inclusion and exclusion criteria. A total of 384 elderly patients undergoing abdominal surgery under general anesthesia were enrolled in a grade A tertiary hospital in Chengdu, Sichuan Province from October 2021 and October 2022. After anesthesia induction, inflatable warming blankets were routinely used for active heat preservation, and nasopharyngeal temperature was monitored to observe the occurrence of intraoperative hypothermia. Patients were divided into hypothermia group and nonhypothermia group according to whether hypothermia occurred during the operation. Anesthesia recovery time and the incidence of adverse events or unwanted events during anesthesia recovery between the two groups were compared. RESULTS: The numbers (percentage) of 384 patients who underwent abdominal surgery developed intraoperative hypothermia occurred in 240 (62.5%) patients, all of whom had mild hypothermia. There were statistically significant differences between mild hypothermia after active warming and nonhypothermia in the occurrence of shivering (χ2 = 5.197, P = 0.023) and anesthesia recovery time (Z = -2.269, P = 0.02) in elderly patients undergoing abdominal surgery during anesthesia recovery, and there were no statistically significant differences in hypoxemia, nausea or vomiting, hypertension, hypokalemia, hypocalcemia, analgesic drug use,postoperative wound infection or postoperative hospitalization days. CONCLUSIONS: The incidence of intraoperative mild hypothermia after active warming was high in elderly patients who underwent abdominal surgery. Mild hypothermia increased the incidence of shivering and prolonged anesthesia recovery time in elderly patients undergoing abdominal surgery.

A multi-center study to predict the risk of intraoperative hypothermia in gynecological surgery patients using preoperative variables.

OBJECTIVES: Hypothermia is highly common in patients undergoing gynecological surgeries under general anesthesia, so the length of hospitalization and even the risk of mortality are substantially increased. Our aim was to develop a simple and practical model to preoperatively identify gynecological surgery patients at risk of intraoperative hypothermia. METHODS: In this retrospective study, we collected data from 802 patients who underwent gynecological surgery at three medical centers from June 2022 to August 2023. We further allocated the patients to a training group, an internal validation group, or an external validation group. The preliminary predictive factors for intraoperative hypothermia in gynecological patients were determined using the least absolute shrinkage and selection operator (LASSO) method. The final predictive factors were subsequently identified through multivariate logistic regression analysis, and a nomogram for predicting the occurrence of hypothermia was established. RESULTS: A total of 802 patients were included, with 314 patients in the training cohort (mean age 48.5 ± 12.6 years), 130 patients in the internal validation cohort (mean age 49.9 ± 12.5 years), and 358 patients in the external validation cohort (mean age 47.6 ± 14.0 years). LASSO regression and multivariate logistic regression analyses indicated that body mass index, minimally invasive surgery, baseline heart rate, baseline body temperature, history of previous surgery, and aspartate aminotransferase level were associated with intraoperative hypothermia in gynecological surgery patients. This nomogram was constructed based on these six variables, with a C-index of 0.712 for the training cohort. CONCLUSIONS: We established a practical predictive model that can be used to preoperatively predict the occurrence of hypothermia in gynecological surgery patients. CLINICAL TRIAL REGISTRATION: chictr.org.cn, identifier ChiCTR2300071859.

Clinical Characteristics, Etiology, and Outcomes of Hypothermia in Well-appearing Children Referred to the Emergency Department.

BACKGROUND: Hypothermia, as a sign of serious bacterial infection (SBI) in children and infants older than 90 days is poorly characterized, especially in the post-pneumococcal vaccine era. OBJECTIVES: To assess the prevalence of SBI in children and infants presenting to the pediatric emergency department (PED) with reported or documented hypothermia. METHODS: Retrospective data analysis was conducted of all well-appearing children aged 0-16 years who presented with a diagnosis of hypothermia at two tertiary PEDs from 2010 to 2019. RESULTS: The study comprised 99 children, 15 (15.2%) age 0-3 months, 71 (71.7%) 3-36 months, and 13 (13.1%) > 36 months. The youngest age group had increased length of stay in the hospital (P < 0.001) and increased rates of pediatric intensive care unit admissions (P < 0.001). Empirical antibiotic coverage was initiated in 80% of the children in the 0-3 months group, 21.1% in the 3-36 months group, and 15.4% in > 36 months (P < 0.001). Only one case of SBI was recorded and no bacteremia or meningitis. Hypothermia of unknown origin was the most common diagnosis in all age groups (34%, 42%, 46%), respectively, followed by bronchiolitis (26%) and hypoglycemia (13.3%) for 0-3 month-old children, unspecified viral infection (20%) and otitis media (7%) for 3-36-month old, and unspecified viral infection (23%) and alcohol intoxication (15.2%) in > 36 months. CONCLUSIONS: There is a low incidence of SBI in well-appearing children presenting to the PED with hypothermia and a benign course and outcome in those older than 3 months.

Factors Influencing the Occurrence of Intraoperative Hypothermia in Patients Undergoing General Anesthesia Intervention: A Study in a Tertiary Care Hospital.

BACKGROUND Intraoperative and postoperative hypothermia of patients can be caused by the use of anesthetic drugs and the complicated and time-consuming procedures of interventional surgery. This retrospective study included 184 patients to investigate the incidence and factors associated with hypothermia during intraoperative anesthesia in a single center in China between January and October 2023. MATERIAL AND METHODS A convenient sampling method was used to select 184 patients who underwent general anesthesia intervention in a tertiary hospital in Sichuan Province from January to October 2023 as the study population. The independent factors influencing the occurrence of intraoperative hypothermia were analyzed. A survey was conducted to collect 5 demographic factors, 4 preoperative-related factors, and 10 surgically related factors. According to the occurrence of intraoperative hypothermia, the independent influencing factors of unplanned hypothermia during perioperative period were further analyzed. RESULTS Among 184 patients, 64 (34.78%) experienced perioperative unplanned hypothermia, of which 5 (7.81%) cases occurred before the start of surgery, 7 (10.94%) occurred before the start of surgery after anesthesia, and 52 (81.25%) occurred during surgery. Logistic regression analysis showed that body temperature at the beginning of surgery (P<0.001), set operating room temperature (P<0.001), duration of anesthesia (P=0.006), and age (P=0.001) were independent influencing factors for unplanned hypothermia during perioperative period. CONCLUSIONS The incidence of intraoperative hypothermia is high in patients undergoing general anesthesia interventions. Age, duration of anesthesia, set operating room temperature, and body temperature at the beginning of the operation were independent influencing factors for the occurrence of unplanned hypothermia during the perioperative period.

Delayed Rewarming Thrombocytopenia: A Suggested Preventable and Treatable Cause of Rewarming Deaths.

The lack of a consensus of accepted prognostic factors in hypothermia suggests an additional factor has been overlooked. Delayed rewarming thrombocytopenia (DRT) is a novel candidate for such a role. At body temperature, platelets undergoing a first stage of aggregation are capable of progression to a second irreversible stage of aggregation. However, we have shown that the second stage of aggregation does not occur below 32°C and that this causes the first stage to become augmented (first-stage platelet hyperaggregation). In aggregometer studies performed below 32°C, the use of quantities of ADP that cause a marked first-stage hyperaggregation can cause an augmented second-stage activation of the platelets during rewarming (second-stage platelet hyperaggregation). In vivo, after 24 hours of hypothermia, platelets on rewarming seem to undergo second-stage hyperaggregation, from ADP released from erythrocytes, leading to life-threatening thrombocytopenia. This hyperaggregation is avoidable if heparin is given before the hypothermia or if aspirin, alcohol or platelet transfusion is given during the hypothermia before reaching 32°C on rewarming. Many of the open questions existing in this field are explained by DRT. Prevention and treatment of DRT could be of significant value in preventing rewarming deaths and some cases of rescue collapse. Performing platelet counts during rewarming will demonstrate potentially fatal thrombocytopenia and enable treatment with platelet infusions aspirin or alcohol.

Development and Validation of a Predictive Model for Intraoperative Hypothermia in Elderly Patients Undergoing Craniocerebral Tumor Resection: A Retrospective Cohort Study.

OBJECTIVE: Timely identification of elderly patients who are at risk of developing intraoperative hypothermia (IH) is imperative to enable appropriate interventions. This study aimed to develop a nomogram for predicting the risk of IH in elderly patients undergoing resection of craniocerebral tumor, and to validate its effectiveness. METHODS: Elderly patients who underwent craniocerebral tumor resection at a large tertiary hospital in eastern China between January 2019 and December 2022 were included (n = 988). The study population was divided into a training set and a validation set by time period. Risk factors identified through the Least Absolute Shrinkage and Selection Operator method and logistic regression analysis were used to establish the nomogram. The model was validated internally by Bootstrap method and externally by validation set through receiver operating characteristic curve analysis, Hosmer-Lemeshow test, and decision curve analysis. RESULTS: A total of 273 (27.6%) patients developed IH. Duration of anesthesia (P < 0.001), blood loss (P < 0.001), preoperative temperature (P < 0.001), tumor location (P < 0.001), age (P < 0.05), and mean arterial pressure (P < 0.05) were identified as independent risk factors for IH. A nomogram integrating these 6 factors was constructed. The area under the curve was 0.773 (95% confidence interval: 0.735-0.811) (70.5% specificity and 75.0% sensitivity), indicating good predictive performance. The decision curve analysis demonstrated the clinical benefit of using the nomogram. CONCLUSIONS: Our model showed good performance in identifying elderly patients who are at high risk of developing IH during craniocerebral tumor resection. The nomogram can help inform timely preventive interventions.

Introduction of a Warming Bundle to Reduce Hypothermia in Neonatal Surgical Patients.

INTRODUCTION: Hypothermia in the neonatal surgical population has been linked with significant morbidity and mortality. Our goal was to decrease intra and postoperative hypothermia. INTERVENTION: In November 2021, a radiant warmer and hat were included along with standard warming methods prior to the start of General Surgery procedures to minimize episodes of hypothermia. PRIMARY OUTCOME: Core body temperature was measured pre, intra and post-operatively. METHODS: Data were prospectively collected from electronic medical records from July 2021 to March 2023. A retrospective analysis was performed. Hypothermia was defined as a temperature <36.5C. Control charts were created to analyze the effect of interventions. RESULTS: A total of 277 procedures were identified; 226 abdominal procedures, 31 thoracic, 14 skin/soft tissue and 6 anorectal. The median post-natal age was 36.1 weeks (IQR: 33.2-39.2), with a pre-surgical weight of 2.3 kg (IQR: 1.6-3.0) and operative duration of 181 min (IQR: 125-214). Hat and warmer data were unavailable for 59 procedures, both hat and warmer were used for 51 % procedures, hat alone for 29 %, warmer alone for 10 % and neither for 10 % of procedures. Over time there was a significant increase in hat utilization while warmer usage was unchanged. There was a significant increase in the mean lowest intra-operative temperature and decrease in proportion of hypothermic patients intra-operatively and post-operatively. CONCLUSIONS: The inclusion of a radiant warmer and hat decreased the proportion of hypothermic patients during and after surgery. Further studies are necessary to analyze the impact on surgical outcomes. LEVEL OF EVIDENCE: III.