Estimation of the difference between peritoneal microenvironment and core body temperature during laparoscopic surgery - a prospective observational study.

Maintaining patients' temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th-75th percentile: 0.2-0.8] °C at the beginning to 2.3 [2.1-2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P < 0.001 for both parameters). Core vs. intraperitoneal temperature difference increased linearly by 0.01 T °C per minute of pneumoperitoneum time up to 120 min and then 0.05 T °C per minute. Each insufflated liter per unit of time, i.e. every 10 min, increased the temperature difference by approximately 0.009 T °C. Our findings highlight the impact of pneumoperitoneum duration and CO2 insufflation volume on the difference between core and intraperitoneal temperatures. Implementing adequate external warming during laparoscopic surgery effectively maintains core temperature despite the use of dry and unwarmed CO2 gases, but peritoneal hypothermia remains a concern, suggesting the importance of further research into regional effects.Trial registration: Clinicaltrials.gov: NCT04294758.

Comparison of prewarming plus intraoperative warming with intraoperative warming alone in patients undergoing minimally invasive thoracic or abdominal surgery: A systematic review and meta-analysis.

OBJECTIVE: Prewarming has been recommended to reduce intraoperative hypothermia. However, the evidence is unclear. This review examined if prewarming can prevent intraoperative hypothermia in patients undergoing thoracoscopic and laparoscopic surgeries. METHODS: PubMed, CENTRAL, Web of Science, and Embase databases were searched for randomized controlled trials (RCTs) up to 15th January 2024. The primary outcome of interest was the difference in intraoperative core temperature. The secondary outcomes were intraoperative hypothermia (<36°) and postoperative shivering. RESULTS: Seven RCTs were eligible. Meta-analysis showed that intraoperative core temperature was significantly higher at the start or within 30mins of the start of the surgery (MD: 0.32 95% CI: 0.15, 0.50 I2 = 94% p = 0.0003), 60 mins after the start of the surgery (MD: 0.37 95% CI: 0.24, 0.50 I2 = 81% p<0.00001), 120 mins after the start of the surgery (MD: 0.34 95% CI: 0.12, 0.56 I2 = 88% p = 0.003), and at the end of the surgery (MD: 0.35 95% CI: 0.25, 0.45 I2 = 61% p<0.00001). The incidence of shivering was also significantly lower in the prewarming group (OR: 0.18 95% CI: 0.08, 0.43 I2 = 0%). Prewarming was also associated with a significant reduction in the risk of hypothermia (OR: 0.20 95% CI: 0.10, 0.41 I2 = 0% p<0.0001). The certainty of the evidence assessed by GRADE was "moderate" for intraoperative core temperatures at all time points and "low" for minimal intraoperative core temperature, shivering, and hypothermia. CONCLUSION: Moderate to low-quality evidence shows that prewarming combined with intraoperative warming, as compared to intraoperative warming alone, can improve intraoperative temperature control and reduce the risk of hypothermia and shivering in patients undergoing thoracoscopic and laparoscopic procedures.

Association Between Persistent Hypothermia After Cardiopulmonary Bypass in Neonates and Odds of Serious Complications.

IMPORTANCE: Persistent hypothermia after cardiopulmonary bypass (CPB) in neonates with congenital heart defects (CHD) has been historically considered benign despite lack of evidence on its prognostic significance. OBJECTIVES: Examine associations between the magnitude and pattern of unintentional postoperative hypothermia and odds of complications in neonates with CHD undergoing CPB. DESIGN: Retrospective cohort study. SETTING: Single northeastern U.S., urban pediatric quaternary care center with an established cardiac surgery program. PARTICIPANTS: Population-based sample of neonates greater than or equal to 34 weeks gestation undergoing their first CPB between 2015 and 2019. INTERVENTIONS: None. MAIN OUTCOMES AND MEASUREMENTS: Hourly temperature measurements for the first 48 postoperative hours were extracted from inpatient medical records, and clinical characteristics and outcomes were accessed through the local patient registry. Group-based trajectory modeling (GBTM) identified latent temporal temperature trajectories. Associations of trajectories with outcomes were assessed using multivariable binary logistic regression. Outcomes (postoperative complications) were manually adjudicated by experts or were predefined by the patient registry. RESULTS: Four hundred fifty neonates met inclusion criteria. Their mean (sd) gestational age was 38 weeks (1.3), mean (sd) birth weight was 3.19 kilograms (0.55), median (interquartile range) surgical age was 4.7 days (3.3-7.0), 284 of 450 (63%) were male, and 272 of 450 (60%) were White. GBTM identified three distinct curvilinear temperature trajectories: persistent hypothermia (n = 38, 9%), resolving hypothermia (n = 233, 52%), and normothermia (n = 179, 40%). Compared with the normothermic group, those with persistent hypothermia had significantly higher odds of cardiac arrest, actionable arrhythmia, delayed first successful extubation, prolonged cardiac ICU length of stay, very poor weight gain, and 30-day hospital mortality. The persistent hypothermia group was characterized by greater odds of having a lower gestational age, more prevalent neurologic abnormalities, more unplanned reoperations, and a low surgical mortality risk assessment. CONCLUSIONS: Persistent postoperative hypothermia in neonates after CPB is independently associated with having greater odds of complications. Recovery patterns from postoperative hypothermia may be a clinically useful marker to identify patient instability in neonates. Additional research is needed for causal modeling and prospective validation before clinical adoption.

Risk Factors for Perioperative Hypothermia in Pregnant Women undergoing Cesarean Section: A Systematic Review and Meta-Analysis.

AIM: Hypothermia is one of the common complications of cesarean section, which has a serious impact on intraoperative surgical safety and postoperative recovery of pregnant women. Mitigation of the risk factors of hypothermia in pregnant women undergoing cesarean section may reduce the probability of its occurrence and improve the perioperative comfort of pregnant women. Therefore, this study systematically evaluates the influencing factors of hypothermia in patients undergoing cesarean section, aiming to provide references for the prevention of hypothermia in pregnant women undergoing cesarean section. METHODS: A systematic search was conducted across various databases, including PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and Chinese Biomedical Literature databases to gather observational studies on the factors affecting hypothermia in pregnant women undergoing cesarean section. The search deadline was January 30, 2024. Two researchers independently screened literature, extracted data, evaluated quality, and crosschecked the outcomes. Meta analysis was conducted using RevMan 5.3 and Stata17.0. RESULTS: Twelve studies were included in this review, all of which were case-control studies conducted from 2014 to 2022, encompassing a total of 5561 pregnant women. The quality of the studies included was average or above. The meta-analysis results showed that body mass index (mean difference (MD) = -1.47; 95% confidence interval (CI) [-2.84, -0.11]; p = 0.03), operating room temperature (odds ratio (OR) = 2.08; 95% CI [1.56, 2.76]; p < 0.00001), anesthesia method (OR = 1.84; 95% CI [1.40, 2.42]; p < 0.0001), fluid loss (MD = 160.09; 95% CI [77.31, 242.87]; p = 0.0002), flushing volume (MD = 66.43; 95% CI [8.46, 124.40]; p = 0.02), and hypothyroidism (OR = 2.29; 95% CI [1.61, 3.27]; p < 0.00001) were risk factors for perioperative hypothermia in pregnant women undergoing cesarean section (p < 0.05). CONCLUSIONS: The occurrence of hypothermia in pregnant women during the perioperative period is influenced by factors such as low body mass index, spinal anesthesia, low operating room temperature, intraoperative fluid loss, large flushing volume, and hypothyroidism.

An unusual cause of neonatal hypothermia and shock in the emergency department: Diamond Blackfan Anemia.

Diamond Blackfan Anemia (DBA) is a rare disease characterized by anemia secondary to impaired red blood cell production from bone marrow failure. We present a case of infantile hypothermia and shock caused by this clinical pathology. A seven-week-old infant was brought to the emergency department by the father with the chief complaint of abnormal breathing and low activity level throughout the day. Medical history was unremarkable for both the patient and the family. On examination, the infant was breathing 30 breaths per minutes, had a heart rate of 116, and a core temperature of 33 degrees Celsius. The infant was ashen in color, limp, with grunted breathing and minimal movement. Numerous abnormal laboratory readings were reported, with the most significant being a hemoglobin of 1.7 and a hematocrit of 7.4. Emergent blood transfusion was initiated, and the patient was eventually air-lifted to a pediatric hospital two hours away. This case highlights the imperative of a thorough history and examination and consideration of a broad differential for neonatal hypothermia and shock, especially in the setting of no obvious bleeding.

Hypothermia and the Global War on Terror: 18 Years of Minimal Progress.

INTRODUCTION: The association between hypothermia, coagulopathy, and acidosis in trauma is well described. Hypothermia mitigation starts in the prehospital setting; however, it is often a secondary focus after other life-saving interventions. The deployed environment further compounds the problem due to prolonged evacuation times in rotary wing aircraft, resource limitations, and competing priorities. This analysis evaluates hypothermia in combat casualties and the relationship to resuscitation strategy with blood products. METHODS: Using the data from the Department of Defense Joint Trauma Registry from 2003 to 2021, a retrospective analysis was conducted on adult trauma patients. Inclusion criteria was arrival at the first military treatment facility (MTF) hypothermic (<95ºF). Study variables included: mortality, year, demographics, battle vs non-battle injury, mechanism, theater of operation, vitals, and labs. Subgroup analysis was performed on severely injured (15 < ISS < 75) hypothermic trauma patients resuscitated with whole blood (WB) vs only component therapy. RESULTS: Of the 69,364 patients included, 908 (1.3%) arrived hypothermic; the vast majority of whom (N = 847, 93.3%) arrived mildly hypothermic (90-94.9°F). Overall mortality rate was 14.8%. Rates of hypothermia varied by year from 0.7% in 2003 to 3.9% in 2014 (P <0.005). On subgroup analysis, mortality rates were similar between patients resuscitated with WB vs only component therapy; though base deficit values were higher in the WB cohort (-10 vs -6, P < 0.001). CONCLUSION: Despite nearly 20 years of combat operations, hypothermia continues to be a challenge in military trauma and is associated with a high mortality rate. Mortality was similar between hypothermic trauma patients resuscitated with WB vs component therapy, despite greater physiologic derangements on arrival in patients who received WB. As the military has the potential to conduct missions in environments where the risk of hypothermia is high, further research into hypothermia mitigation techniques and resuscitation strategies in the deployed setting is warranted.

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.

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.

[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.

Effect of irrigation solution temperature on complications of percutaneous nephrolithotomy: a systematic review of the literature, meta-analysis and trial sequential analysis of randomized clinical trials.

INTRODUCTION: The optimal temperature of irrigation solution in patients undergoing PCNL is still unclear. Accordingly, this study aims to investigate the effects of different irrigation solution temperatures (cold/room temperature irrigation fluid versus warm/body temperature fluid). Our primary endpoint was hypothermia rate. Secondary outcomes were shivering rate, mean temperature decrease, mean patient final temperature, blood loss, and operative time. EVIDENCE ACQUISITION: This systematic review was conducted in accordance with PRISMA guidelines. Multiple databases were searched in November 2023. Among 299 studies screened, eight were selected for full-text review, resulting in four randomized clinical trials that fit inclusion criteria and desired outcomes. Studies selection and data extraction were performed by multiple reviewers and a random-effects model was used for pooling of data. EVIDENCE SYNTHESIS: The primary outcome, hypothermia rate, showed a significant statistical difference between groups, occurring less frequently in the experimental group (35-37 ºC) than in the cold/room temperature irrigation group (RR 0.64;95%CI 0.46, 0.89; P<0.008; I2=33%). Secondary outcomes such as shivering rate (RR 0.46; 95%CI 0.31, 0.67; P<0.0001; I2=0%) and mean final temperatures (MD 0.43; 95%CI 0.12, 0.75; I2=82%) also showed statistically significant differences between groups, favoring the irrigation with heated fluid. CONCLUSIONS: There was a decreased rate of hypothermia and shivering among patients undergoing PCNL with warm irrigation fluid. Mean final temperatures were also higher in the experimental group. As to blood loss, mean hemoglobin decrease showed no statistically significant difference between groups, prompting further investigation of the influence of Irrigation solution temperature on blood loss volume.

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.

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.

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.

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.