Temperature monitoring and perioperative thermoregulation

Preoperative thoracic paravertebral block provides greater benefits for body temperature protection in patients undergoing thoracoscopic lung surgery: a retrospective cohort study

BACKGROUND

Perioperative hypothermia can lead to a variety of adverse events that hinder rapid recovery after surgery in clinical settings. General anesthesia combined with paravertebral block (PVB) may add additional heat loss and thus increase the incidence of hypothermia in patients undergoing thoracoscopic lung surgery. However, gaps in the knowledge of the influence of the PVB time sequence on patients' body temperature remain. The aim of this study was to explore the potential impact of the time sequence of PVB on the risk of hypothermia.

METHODS

Patients aged 18-85 years who underwent thoracic PVB (TPVB) and thoracoscopic lung surgery at a tertiary hospital were retrospectively included. All the patients were divided into a pre-PVB group and a post-PVB group on the basis of the time sequence of PVB. The demographic, anesthesia-related and surgery-related data of the patients were collected. Propensity score matching was applied, and outcomes were compared between the two groups. The primary outcome was the incidence of hypothermia in the postanaesthesia care unit (PACU). The secondary outcomes included the occurrence of chill and delayed awakening, the numeric rating scale (NRS) score, extubation time and length of stay (LOS) in the PACU.

RESULTS

A total of 1001 patients were enrolled, with 746 patients in the pre-PVB group and 255 patients in the post-PVB group. After 1:1 propensity score matching, 222 patients were included in each group. The results revealed that body temperature was significantly different between the two groups (pre-PVB group, 36.1 [36.0-36.2]°C; post-PVB group, 36.0 [36.0-36.2]°C; P = 0.012), and the incidence of hypothermia was greater in the post-PVB group than that in the pre-PVB group (24.8% vs. 16.7%, P = 0.047). The NRS scores in the PACU were higher in the pre-PVB group (0 [0-1] vs. 0 [0-0], P = 0.041). There was no statistically significant difference in the other outcomes between the two groups.

CONCLUSIONS

Preoperative TPVB offers more benefits for body temperature protection in patients undergoing thoracoscopic lung surgery, but it slightly offsets the analgesic efficacy in the PACU.

The Correlation Between Preoperative Perfusion Index and Intraoperative Hypothermia During Laparoscopic Radical Surgery for Urological Malignancies

This study aimed to explore the relationship between preoperative baseline perfusion index (PI) and intraoperative hypothermia during general anesthesia. PI reflects the peripheral perfusion status, which may be associated with the decrease of core temperature during general anesthesia, as the redistribution of temperature from the core compartment to the peripheral compartment depends on the peripheral perfusion status. A total of 68 patients underwent radical surgery for urological malignancies in this study. The baseline PI value was measured upon entering the operating room. Core temperature was continuously monitored using a nasal pharyngeal probe from anesthesia induction to the end of surgery, with temperature data recorded every 15 minutes. Univariate and multivariate logistic regression analyses were used to identify risk factors for intraoperative hypothermia. Intraoperative hypothermia occurred in 26 patients, whose baseline PI (2.70 ± 0.73) was significantly lower than that of the normothermic group (3.65 ± 1.05), with P<0.05. The baseline PI was independently associated with intraoperative hypothermia (PI: [OR] 0.375, 95% confidence interval [CI]: 1.584-6.876, p = 0.001). This study suggests that low baseline PI is an independent factor associated with intraoperative hypothermia. In future studies, PI value could be considered as a predictor for the treatment of intraoperative hypothermia.

Impact of heat stress and protective clothing on healthcare workers: health, performance, and well-being in hospital settings

INTRODUCTION

Heat stress poses a recognized threat to human health. Despite growing evidence, its impact on healthcare workers (HCWs) remains underexplored. This study evaluates occupational heat stress in HCWs, assessing physiological responses and subjective well-being.

METHODS

Twelve HCWs from a German university hospital were monitored in non-air-conditioned intensive care units (ICU) and non-ICU settings during the summer of 2022 (mean indoor temperature of 26.5 °C) and again in the autumn of the same year or in March 2023 (mean indoor temperature of 23.6 °C). Physiological data (core body temperature, heart rate, and skin temperature) and subjective perceptions were measured using wearable sensors and questionnaires.

RESULTS

In summer, mean core body and skin temperatures were higher by 0.4 °C and 0.3 °C, respectively. ICU workers exhibited higher heart rates and reported greater mental demands, frustration, and discomfort, particularly when using personal protective equipment (PPE). Common symptoms included sweating, fatigue, and headaches.

CONCLUSION

We observed some evidence suggesting that elevated indoor temperatures and reported PPE usage contribute to increased HCWs' heat strain, which could potentially affect health, safety, and performance. Given the observed trends, we recommend considering cooling vests and revising workplace standards to mitigate heat stress.

Racial Differences in Temporal Thermometry and Association with Delayed Sepsis Bundle Care

Importance

Early identification of fever or hypothermia is crucial for diagnosing sepsis. Despite their increased use across healthcare systems, concerns have been raised about the accuracy of temporal thermometers among Black patients.

Objective

To study the performance of temporal thermometry across race and ethnicity, and its impact on the initiation of the sepsis management bundle (SEP-1).

Design

In this retrospective cohort study, records from 2008-2024 in 123 U.S. hospitals were analyzed, including electronic health records from Duke, MIMIC-IV, eICU-CRD-1, and eICU-CRD-2. Patients were included if they had a temporal measurement within one hour of an oral/core measurement (esophageal, bladder, rectal).

Main Outcomes and Measures

Hidden Fever was defined when the temporal thermometer read ≤ 38°C but oral/core measurement > 38°C and Hidden Hypothermia as temporal temperature ≥ 36°C but oral/core < 36°C. The primary outcome was Hidden Hyper/Hypothermia (HHH) when either Hidden Fever or Hidden Hypothermia happened. Observed Hyper / Hypothermia (OHH) corresponded to an agreement between both measurements, used as a control. To study the impact of temporal thermometry underperformance on SEP-1 bundle initiation, we assessed time to culture ordering, antibiotics administration, and lactate measurement. A composite of these three, whichever happened first, was defined as our secondary outcome.

Results

6,921 paired temperature measurements were studied for the primary outcome analysis, corresponding to 4,248 hospitalizations (2.6% Asian; 12.4% Black; 2.6% Hispanic/Latino; 83.4% White; 44.9% female; 7.7% with HHH) from 115 hospitals. After adjusting for confounders, Black [OR (95% CI): 1.760 (1.219, 2.541), p =0.003] and Hispanic/Latino [OR (95% CI): 2.183 (1.226, 3.888), p= 0.008] patients were significantly more likely to present with HHH than White patients. For the study of the secondary outcome, 434 patients had either OHH or HHH. Compared to patients with OHH, patients with HHH had significantly delayed secondary outcomes, with log-rank p-value of 0.002.

Conclusions and Relevance

Solely relying on temporal thermometry can lead to missed hyper/hypothermia events, especially among Asian, Black, and Hispanic patients. This has been associated with delays in the initiation of the SEP-1 bundle, which may hamper health systems' compliance with reimbursement programs.

Key Points

Question: Are there racial differences in temporal thermometry that result in missed hyper/hypothermia, and are these associated with delays in sepsis bundle care (SEP-1) initiation?Findings: In this multicenter retrospective cohort study of 4,248 hospitalizations, Asian, Black, and Hispanic patients were more likely to have hidden hyper/hypothermia when using temporal thermometers, as compared to oral/core measurements. These missed events were associated with delayed SEP-1 interventions (three out of four were studied: culture orders, antibiotic administration, and lactate measurements).Meaning: Reliance on temporal thermometry could exacerbate health disparities and hamper hospital systems' compliance with reimbursement programs. Temporal thermometers should therefore be routinely validated with contact thermometers.

ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine

BACKGROUND

To provide recommendations on risk mitigation, diagnosis and treatment of infectious complications associated with the practice of regional anesthesia, acute and chronic pain management.

METHODS

Following board approval, in 2020 the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine) commissioned evidence-based guidelines for best practices for infection control. More than 80 research questions were developed and literature searches undertaken by assigned working groups comprising four to five members. Modified US Preventive Services Task Force criteria were used to determine levels of evidence and certainty. Using a modified Delphi method, >50% agreement was needed to accept a recommendation for author review, and >75% agreement for a recommendation to be accepted. The ASRA Pain Medicine Board of Directors reviewed and approved the final guidelines.

RESULTS

After documenting the incidence and infectious complications associated with regional anesthesia and interventional pain procedures including implanted devices, we made recommendations regarding the role of the anesthesiologist and pain physician in infection control, preoperative patient risk factors and management, sterile technique, equipment use and maintenance, healthcare setting (office, hospital, operating room), surgical technique, postoperative risk reduction, and infection symptoms, diagnosis, and treatment. Consensus recommendations were based on risks associated with different settings and procedures, and keeping in mind each patient's unique characteristics.

CONCLUSIONS

The recommendations are intended to be multidisciplinary guidelines for clinical care and clinical decision-making in the regional anesthesia and chronic interventional pain practice. The issues addressed are constantly evolving, therefore, consistent updating will be required.

Evaluation of non-invasive sensors for monitoring core temperature

We evaluated the accuracy and precision of zero-heat flux (ZHF) and dual sensor (DS) non-invasive temperature probes in intensive care unit (ICU) patients undergoing hypothermic temperature control, hypothesizing that both devices would accurately estimate core temperature. In a single-center prospective cohort study, we enrolled 35 ICU patients and applied continuous, non-invasive ZHF and/or DS probes to the lateral forehead or anterior chest to collect 358 observations. Conditions potentially influencing temperature estimation were recorded. Using Bland-Altman analysis with multiple paired observations per individual, we compared the bias between non-invasive probes and direct core temperature measurements. Lin's concordance coefficient (LCC) was computed to quantify precision. The mean bias between the ZHF probe and invasive temperature was + 0.98 °C; for the DS probe, it was - 2.19 °C. In hypothermic patients, the ZHF probe's accuracy improved (bias + 0.28 °C, LCC 0.86), while the DS probe remained inaccurate (bias - 2.52 °C, LCC 0.07). Clinical confounders like vasoactive agents or temperature control devices did not consistently affect bias, accuracy, or precision. Neither the ZHF nor DS non-invasive probes provided sufficient accuracy or precision to guide clinical decisions in the ICU. These results contrast with previous studies reporting biases within ± 0.5 °C. However, the ZHF probe showed promising limited deviation, especially in hypothermic patients.

Analysis of Personalized Cardiovascular Drug Therapy: From Monitoring Technologies to Data Integration and Future Perspectives

Cardiovascular diseases have long been a major challenge to human health, and the treatment differences caused by individual variability remain unresolved. In recent years, personalized cardiovascular drug therapy has attracted widespread attention. This paper reviews the strategies for achieving personalized cardiovascular drug therapy through traditional dynamic monitoring and multidimensional data integration and analysis. It focuses on key technologies for dynamic monitoring, dynamic monitoring based on individual differences, and multidimensional data integration and analysis. By systematically reviewing the relevant literature, the main challenges in current research and the proposed potential directions for future studies were summarized.

Spinal Anesthesia in a Patient With Cold Agglutinin Disease Presenting for Total Knee Arthroplasty in a Community Hospital Setting

Idiopathic cold agglutinin disease is a form of autoimmune hemolytic anemia (AIHA) characterized by autoantibody-mediated red blood cell (RBC) agglutination and hemolytic anemia at colder temperatures. Due to the increased risk of clinical manifestations of this condition at cold temperatures, this condition presents unique thermoregulatory considerations perioperatively. There is a risk of hypothermia in patients who undergo both general and regional anesthesia due to impairments in thermoregulatory control. However, there is a paucity of literature detailing perioperative considerations for this patient population who undergo neuraxial anesthesia. In this report, the physiology of perioperative hypothermia and the thermoregulatory impairments seen in both general and neuraxial anesthesia are reviewed. This case report details the perioperative management and warming strategies for an 83-year-old female with a history of idiopathic cold agglutinin disease who underwent spinal anesthesia for an elective primary total knee arthroplasty (TKA) in a community hospital setting. This report demonstrates that under a strict temperature management strategy, either spinal or general anesthesia may be considered for this patient population. Pre-operative optimization, stability of symptoms, the frequency of laboratory monitoring required, and the need for rapid cold agglutinin-directed therapy influence the decision as to whether these cases can be safely performed in an ambulatory community hospital setting versus a tertiary care center.

Intraoperative zero-heat-flux thermometry overestimates nasopharyngeal temperature by 0.39 °C: an observational study in patients undergoing congenital heart surgery

During surgery for congenital heart disease (CHD) temperature management is crucial. Vesical (Tves) and nasopharyngeal (TNPH) temperature are usually measured. Whereas Tves slowly responds to temperature changes, TNPH carries the risk of bleeding. The zero-heat-flux (ZHF) temperature monitoring systems SpotOn™ (TSpotOn), and Tcore™ (Tcore) measure temperature non-invasively. We evaluated accuracy and precision of the non-invasive devices, and of Tves compared to TNPH for estimating temperature. In this prospective observational study in pediatric and adult patients accuracy and precision of TSpotOn, Tcore, and Tves were analyzed using the Bland-Altman method. Proportion of differences (PoD) and Lin´s concordance correlation coefficient (LCC) were calculated. Data of 47 patients resulted in sets of matched measurements: 1073 for TSpotOn vs. TNPH, 874 for Tcore vs. TNPH, and 1102 for Tves vs. TNPH. Accuracy was - 0.39 °C for TSpotOn, -0.09 °C for Tcore, and 0.07 °C for Tves. Precisison was between - 1.12 and 0.35 °C for TSpotOn, -0.88 to 0.71 °C for Tcore, and - 1.90 to 2.05 °C for Tves. PoD ≤ 0.5 °C were 71% for TSpotOn, 71% for Tcore, and 60% for Tves. LCC was 0.9455 for TSpotOn, 0.9510 for Tcore, and 0.9322 for Tves. Temperatures below 25.2 °C (TSpotOn) or 27.1 (Tcore) could not be recorded non-invasively, but only with Tves. Trial registration German Clinical Trials Register, DRKS00010720.

Agreement of zero-heat-flux thermometry compared with infrared tympanic temperature monitoring in adults undergoing major surgery

The patient's body temperature significantly fluctuates, affected by factors, including anesthesia. The ideal temperature monitoring method that is suitable for perioperative application is of great significance for identifying hypothermia and malignant hyperthermia early, as well as for guiding intraoperative temperature protection. This study aims to compare the cutaneous zero-heat-flux (ZHF) thermometer application in general anesthesia using the infrared tympanic measurement as a reference. We conducted a prospective observational study and enrolled 130 patients scheduled for major surgery with general anesthesia. A forehead ZHF sensor (Tzhf) and an infrared tympanic thermometer (Ttym) were used to continuously measure core temperature. We assessed the agreement using Bland-Altman analysis and concordance correlation coefficient, comparing the paired measurement of Tzhf and Ttym. We further calculated the percentage of difference within 0.5 ℃ between the two devices. Sensitivity, specificity, and predictive values were estimated to interpret the performance of the ZHF thermometer in detecting hypothermia and hyperthermia. The analysis involved 1626 pairs of measurements for the comparison. The mean difference between the ZHF and the tympanic measurements was 0.11 ℃ ± 0.27 ℃, 93.5% of the measurements differences fell within ± 0.5 ℃. Tzhf was significantly correlated with Ttym (r = 0.90). The ZHF thermometry detected the presence of Ttym hypothermia with sensitivity and specificity of 0.89 and 0.88, respectively. Temperature monitoring with the ZHF thermometer indicates a good agreement with the infrared tympanic measurement and a high performance for detecting intraoperative hypothermia.

Dexmedetomidine-associated hypothermia in critical trauma: A case report and literature analysis

RATIONALE

Hypothermia, defined as a core body temperature below 35°C, is a common and serious complication in severe trauma patients, often worsened by hemorrhage and medical interventions. Dexmedetomidine, an α2-adrenergic agonist used for sedation in intensive care units, has known thermoregulatory effects; however, its association with hypothermia in trauma patients remains insufficiently explored.

PATIENT CONCERNS

A 40-year-old male with severe polytrauma from a motor vehicle accident presented in distress, with hypotension, tachycardia, and a baseline temperature of 35.8°C. Despite effective management, he developed profound hypothermia, with a recorded temperature dropping below 34.0°C after switching from midazolam to dexmedetomidine for sedation.

DIAGNOSES

The patient had multiple bilateral rib fractures, a right-sided pneumothorax, and grade 3 liver and grade 5 splenic injuries, along with orthopedic fractures. His Injury Severity Score signified critical trauma, increasing the risk of complications like hypothermia.

INTERVENTIONS

Following stabilization, dexmedetomidine was administered for sedation. Continuous warming interventions were initiated to address hypothermia; however, the temperature continued to decline. Suspecting dexmedetomidine's contribution, its administration was discontinued.

OUTCOMES

After stopping dexmedetomidine, the patient's temperature gradually recovered to 36.8°C within 5 hours. He demonstrated improved consciousness and stable vital signs, subsequently undergoing 2 successful orthopedic surgeries and discharging without further hypothermia-related issues.

LESSONS

This case highlights dexmedetomidine's potential to induce hypothermia in critically ill trauma patients. It stresses the importance of careful temperature monitoring and proactive thermoregulation during sedative administration in intensive care. Further research is needed to explore the prevalence and mechanisms of dexmedetomidine-associated hypothermia in trauma populations.

Strategies for perioperative hypothermia management: advances in warming techniques and clinical implications: a narrative review

Perioperative hypothermia is a frequent clinical complication resulting from the cold environment of the operating room and prolonged skin exposure, leading to adverse outcomes and increased healthcare burdens. To address this issue, this narrative review discusses in detail the currently common warming strategies for perioperative hypothermia .Forced air warming (FAW) systems are widely recognized as the most effective intervention for maintaining core body temperature. Additionally, alternative technologies, such as circulating-water mattresses, carbon-fiber resistive heating systems, self-regulated heated air garments, self-heating blankets, and chemical heat packs, offer diverse advantages and disadvantages. Passive warming methods, including thermal reflective blankets and cotton blankets, provide a cost-effective solution, albeit with reduced efficacy compared to active warming measures. Recent advancements have focused on improving both active and passive warming approaches to balance effectiveness and cost-efficiency. While FAW remains the gold standard, other systems offer specific benefits, such as improved portability and reduced costs, making them suitable for use in diverse clinical scenarios. Effective perioperative temperature management reduces hypothermia-related complications, decreases healthcare expenditures, and provides substantial social and organizational benefits. Thus, selecting the most appropriate warming intervention in clinical practice requires a tailored approach, considering both patient-specific needs and resource availability.

Analysis of the characteristic patterns and risk factors impacting the severity of intraoperative hypothermia in neonates

Background

Although maintaining a stable body temperature during the perioperative period is crucial for the recovery of neonates, hypothermia frequently occurs during surgical procedures in this vulnerable population. A comprehensive analysis of intraoperative details, including medical history and monitoring, is therefore essential for understanding temperature variations and identifying risk factors for severe hypothermia.

Objective

In this study, we delineated the characteristic patterns of intraoperative temperature fluctuations in neonates and determined the risk factors impacting the severity of hypothermia.

Methods

We conducted a retrospective, single-center study, enrolling 648 subjects who underwent surgery under general anesthesia and collected demographic, perioperative, and intraoperative data.

Results

Intraoperative hypothermia occurred in 79.17% of the neonates. Significant risk factors for severe hypothermia included surgery type (OR, 1.183; 95%, CI [1.028-1.358]; p = 0.018), preoperative weight (OR, 0.556; 95% CI [0.412-0.748]; p < 0.01), infusion and transfusion volume (mL/kg) (OR, 1.011; 95% CI [1.001-1.022]; p = 0.018), and duration of hypothermia (OR, 1.011; 95% CI [1.007-1.014]; p < 0.01). Preterm neonates experienced a greater temperature drop than did full-term neonates. The nadir of intraoperative temperature occurred approximately 90 min after surgery, followed by a brief stabilization period and a slow recovery process.

Conclusion

The significant incidence of intraoperative hypothermia in neonates highlights the need for efficient strategies that reduce both the frequency and severity of this condition.

Effect of a Forced-Air Warming Blanket on Different Parts of the Body on Core Temperature of Patients Undergoing Elective Open Abdominal Surgery: A Randomized Controlled Single-Blind Trial

PURPOSE

This study aimed to determine the effect of a forced-air warming blanket placed on different body parts on the core temperature of patients undergoing elective open abdominal surgery.

DESIGN

Prospective, single-center, randomized, controlled, single-blind trial.

METHODS

A total of 537 patients who underwent open abdominal surgery were randomized into groups A, B, and C and provided with different forced-air warming blankets. Group A was given an upper body blanket, group B a lower body blanket, and group C an underbody blanket. The incidence of intraoperative hypothermia, the time maintaining the core temperature over 36 ℃ before hypothermia, the duration of hypothermia, the rewarming rate, and relevant complications were compared among three groups.

FINDINGS

Intraoperative hypothermia occurred in 51.4% of patients in group B, 37.6% of patients in group A, and 34.1% of patients in group C (P = .002). Maintaining the core temperature above 36 ℃ was longer before hypothermia in groups A and C (log-rank P = .006). In groups A and C, the duration of hypothermia was shorter, the rewarming rate was higher, and the incidence of shivering and postoperative nausea and vomiting were lower, compared to group B.

CONCLUSIONS

In patients undergoing elective open abdominal surgery, a forced-air warming blanket on the upper body part or underbody area decreased intraoperative hypothermia, prolonged the time to maintain the core temperature above 36 ℃ before hypothermia, and could better prevent further hypothermia when the core temperature had decreased below 36 ℃. In addition, it was significantly superior in reducing shivering and postoperative nausea and vomiting in the postanesthesia care unit.

Hypothermia and rewarming times during general anesthesia in Hispaniolan Amazon parrots (Amazona ventralis): A comparative study between isoflurane, sevoflurane and desflurane

OBJECTIVE

To evaluate induced hypothermia and rewarming times in Hispaniolan Amazon parrots (HAP; Amazona ventralis) anesthetized using isoflurane, sevoflurane or desflurane, and to describe selected cardiovascular and respiratory effects.

STUDY DESIGN

Randomized, balanced, crossover experimental study.

ANIMALS

A group of 12 adult HAP.

METHODS

Parrots were premedicated with intramuscular butorphanol (0.5 mg kg-1) and anesthetized with the three inhalants with a 7 day washout period between events. Anesthesia was induced using isoflurane at 4 vol%, sevoflurane at 6 vol% or desflurane 12 vol% carried in oxygen, delivered via face mask. After orotracheal intubation, anesthesia maintenance was with end-tidal concentrations of 1.4-2% (Fe'Iso), 2.4-3% (Fe'Sevo) and 8.5-9.2% (Fe'Des). Hypothermia was defined as an esophageal temperature (BT) below 37.8 °C. External heat support was provided when BT dropped to 37.5 °C. Time for temperature decrease from 38.9 °C to 37.5 °C (T1), time to first increase in BT above 37.5 °C (T2) and time from external heat support to achieving 38.9 °C (T3) were recorded and compared via Friedman tests with post hoc Dunn's test. Heart rate, respiratory rate and end-tidal carbon dioxide, amongst other variables, were evaluated.

RESULTS

All inhalants caused hypothermia (T1): isoflurane, 12 (2-37) minutes [median (range)]; sevoflurane, 12 (4-18) minutes; desflurane, 11.5 (6-24) minutes, with no significant differences between treatments (p > 0.05). T2 was significantly (p = 0.042) longer for sevoflurane than for desflurane but not isoflurane. Transient apnea was observed with all inhalants, including 25% of birds anesthetized with sevoflurane. Second-degree atrioventricular block and ventricular escape beats occurred with all inhalants with hypothermia potentially exacerbating cardiac arrhythmias.

CONCLUSIONS AND CLINICAL RELEVANCE

Hypothermia rapidly developed in butorphanol-sedated HAP anesthetized using isoflurane, sevoflurane or desflurane. Sevoflurane prolonged warming time. Hypothermia may be associated with an increased likelihood of bradyarrhythmia in parrots anesthetized with inhalants.

Understanding the role of intraoperative hypothermia in perioperative opioid requirements in immediate implant-based breast reconstruction

BACKGROUND

The relationship between perioperative temperatures and postoperative pain is unknown. The present study investigated the relationship of intraoperative hypothermia and perioperative opioid requirements after immediate implant-based breast reconstruction.

METHODS

A retrospective chart review was conducted on patients undergoing immediate implant-based breast reconstruction from 2019-2023. Patients were classified into the hypothermic group (majority of procedure <36.0 °C) or normothermic group (majority of procedure ≥36.0 °C). Cumulative inpatient opioid requirements (morphine milli-equivalents [MMEs]) and frequency of patients requiring "high-dose opioids" (≥100 MMEs) were collected and compared between the groups.

RESULTS

In total, 536 patients (835 breasts) were included, among whom 135 (25.1%) were hypothermic. The hypothermic group had lower mean intraoperative (88.4 vs. 99.1 MMEs, P = 0.007) and postoperative (45.6 vs. 56.8 MMEs, P = 0.006) than the normothermic group. Mean (B = 14.6, P = 0.004) and nadir (B = 10.4, P = 0.038) intraoperative temperatures directly predicted higher opioid requirements while higher percentages of the procedure time spent under 36 °C (B = -27.6, P = 0.004) predicted lower opioid requirements. The hypothermic group was associated with 66% decreased odds of requiring high-dose opioids after adjusting for differences in patient and operative characteristics (P = 0.007).

CONCLUSION

Hypothermia is associated with decreased perioperative opioid requirements. Future studies should further investigate ideal temperature thresholds for warming protocols to minimize postoperative pain.

Anesthesia for Bronchoscopy-An Update

The field of interventional pulmonology has grown immensely and is increasingly recognized as a subspecialty. The new procedures introduced in the last decade pose unique challenges, and anesthesiologists need to readapt to their specific demands. In this review, we extensively discuss the pathophysiology, technical aspects, preprocedural preparation, anesthetic management, and postprocedural challenges of many new procedures such as navigational bronchoscopy, endobronchial valve deployment, and bronchial thermoplasty. Majority of these procedures are performed under general anesthesia with an endotracheal tube. Total intravenous anesthesia with rocuronium as a muscle relaxant seems to be the standard US practice. The easy availability and proven safety and efficacy of sugammadex as a reversal agent of rocuronium has decreased the need for high-dose remifentanil as an agent to avoid muscle relaxants. Additional research is available with regard to the utility of nebulized lidocaine and is discussed. Finally, two newer drugs administered for conscious sedation (typically without the need of an anesthesiologist) are likely to gain popularity in the future. Remimazolam is a new short-acting benzodiazepine with a relatively faster offset of clinical effects. Dexmedetomidine, a selective adrenergic agonist, is increasingly employed in bronchoscopy as a sedative during bronchoscopic procedures.

Advances in the multimodal management of perioperative hypothermia: approaches from traditional Chinese and Western medicine

PURPOSE

Maintaining normothermia during the perioperative period is crucial for preventing complications, such as surgical site infections, prolonged hospital stays, and adverse cardiovascular events. This study aimed to elucidate methods of perioperative temperature management by integrating Western and traditional Chinese medicine (TCM) approaches. By combining advanced techniques of Western medicine with holistic and preventative practices of TCM, we aimed to provide a comprehensive strategy for effective perioperative thermal regulation.

METHODS

And a comprehensive literature review was conducted to analyze the causes of perioperative hypothermia and methods of perioperative temperature management from both Western and traditional Chinese medicine (TCM) perspectives. Special emphasis was placed on evaluating the underlying factors contributing to perioperative hypothermia, as well as the effectiveness, selection criteria, indications, contraindications, adverse reactions, and potential complications associated with various temperature management techniques.

RESULTS

Effective prevention and management strategies include preoperative risk assessment, physical warming measures, environmental temperature control, pharmacological interventions, perioperative temperature monitoring, comprehensive warming protocols, and postoperative warming and monitoring. Integrating traditional Chinese medicine provides additional methods to enhance overall effectiveness and patient outcomes. By combining these approaches, healthcare providers can significantly reduce the incidence of inadvertent perioperative hypothermia (IPH) and its associated complications, improving patient safety and recovery.

CONCLUSION

For IPH, a complex and challenging medical condition, both traditional Chinese medicine and Western medicine have established their own theoretical bases and developed corresponding prevention and treatment methods. However, it is important to note that although each of these methods has unique value and potential, they also have specific indications and unavoidable limitations. Therefore, by integrating and combining the complementary strengths and resources of traditional Chinese medicine and Western medicine, we can achieve a more comprehensive and effective prevention of IPH, ultimately improving the health and well-being of those affected.

Effects of Optimal Temperature Control in Body Contouring Surgery: A Nonrandomized Controlled Clinical Trial

BACKGROUND

Perioperative hypothermia in plastic surgery has underestimated risks, including increased risk of infection, cardiac events, blood loss, prolonged recovery time, and increased nausea, pain, and opioid usage. Inadequate preventive measures can result in up to 4 hours of normothermia restoration.

OBJECTIVES

The aim was to compare the impact of different strategies for normothermia during plastic surgery procedures and their relationship with clinical outcomes.

METHODS

A nonrandomized clinical trial was conducted in a single center in Bogota, Colombia. We enrolled adult patients undergoing body contouring surgery and divided them into 4 intervention groups with different measures to control body temperature. Univariate and bivariate analyses were performed, comparing several clinical symptoms to evaluate outcomes.

RESULTS

A total of 197 patients were analyzed. Most of them were females (84.3%). Mean age was 38.6 years, and the median procedure duration was 260 minutes. Demographic and clinical characteristics did not exhibit significant differences between the groups. There were notable variations in temperature measurements at crucial moments during the surgical procedure among the groups, attributed to the implementation of distinct thermal protective strategies. Group comparisons showed a relationship between hypothermia and increased nausea, vomiting, shivering, pain, and additional analgesia requirements.

CONCLUSIONS

Incorporation of active thermal protective measures, such as Blanketrol or HotDog, during body contouring procedures, markedly diminishes the risk of hypothermia and enhances overall clinical outcomes. Implementing these active measures to maintain the patient in a state of normothermia not only improves operating room efficiency but also leads to a reduction in recovery room duration.

LEVEL OF EVIDENCE: 3

Agreement between three noninvasive temperature monitoring devices during spinal anaesthesia for caesarean delivery: a prospective observational study

Hypothermia during obstetric spinal anaesthesia is a common and important problem, yet temperature monitoring is often not performed due to the lack of a suitable, cost-effective monitor. This study aimed to compare a noninvasive core temperature monitor with two readily available peripheral temperature monitors during obstetric spinal anaesthesia. We undertook a prospective observational study including elective and emergency caesarean deliveries, to determine the agreement between affordable reusable surface temperature monitors (Welch Allyn SureTemp® Plus oral thermometer and the Braun 3-in-1 No Touch infrared thermometer) and the Dräger T-core© (using dual-sensor heat flux technology), in detecting thermoregulatory changes during obstetric spinal anaesthesia. Predetermined clinically relevant limits of agreement (LOA) were set at ± 0.5 °C. We included 166 patients in our analysis. Hypothermia (heat flux temperature < 36 °C) occurred in 67% (95% CI 49 to 78%). There was poor agreement between devices. In the Bland-Altman analysis, LOA for the heat flux monitor vs. oral thermometer were 1.8 °C (CI 1.7 to 2.0 °C; bias 0.5 °C), for heat flux monitor vs. infrared thermometer LOA were 2.3 °C (CI 2.1 to 2.4 °C; bias 0.4 °C) and for infrared vs. oral thermometer, LOA were 2.0 °C (CI 1.9 to 2.2 °C; bias 0.1 °C). Error grid analysis highlighted a large amount of clinical disagreement between methods. While monitoring of core temperature during obstetric spinal anaesthesia is clinically important, agreement between monitors was below clinically acceptable limits. Future research with gold-standard temperature monitors and exploration of causes of sensor divergence is needed.

Effects of different forced-air warming systems on the core temperature of patients: a manikin and multi-center clinical study

BACKGROUND

The use of forced-air warming (FAW) blankets is widely recognized for preventing shivering and hypothermia in patients under general anesthesia. Various types of products are currently available for hospitals, and we have conducted a preliminary evaluation of insulation equipment based on expert opinions and initial parameters. However, we lack real-world experiments and accurate clinical data to validate these parameters and the accuracy of our decision-making results. This study aims to confirm the effectiveness of different FAW systems by assessing the thermal protection and operational characteristics of the equipment in both experimental and clinical settings, thereby enhancing our evaluation database.

METHODS

In the manikin test, we conducted six tests including heat distribution and heating rate, heater outlet temperature stability, etc. In the clinical study, patients were randomly assigned to four groups [Group A (Bair Hugger Therapy, 3 M, St. Paul, MN, USA; 63500); Group B (EQUATOR® level I, Smith Medical ASD, MN, USA; Snuggle Warm, SW-2013); Group C (Jiang Men Da Cheng Medical Devices Co., Ltd, China; IOB-006); and Group D (Shang Hai Nest Tech Medical Materials Co., Ltd, China; BH-017)], with each group comprising 30 individuals. At the start of anesthesia induction, the FAW blanket was activated and set to 43 °C until the completion of surgery. The primary endpoint was the average core body temperature during surgery. Secondary endpoints included hemodynamic and surgical variables, adverse events, and recovery metrics.

RESULTS

In the manikin test, the observed results of the experimental parameters (heat distribution, air pressure difference, and hole observation test) for Group A are superior to those of the other groups. In the clinical study, although the mean perioperative core body temperature remained above 36 °C across all groups [Group A: 36.31 ± 0.04; Group B: 36.26 ± 0.06; Group C: 36.17 ± 0.03; Group D: 36.25 ± 0.05], patients in Group A maintained higher temperatures compared to the other groups (p < 0.001).

CONCLUSIONS

Among patients undergoing laparoscopic radical resection of colorectal cancer with general anesthesia, all four FAW systems effectively prevented perioperative hypothermia. However, the system in Group A minimized heat loss more effectively than the others, providing superior thermal protection.

TRIAL REGISTRATION

ChiCTR2200065394, 03/11/2022.

Perioperative Quality Improvement in Children's Hospitals Neonatal Consortium NICUs

Infants admitted to NICUs in children's hospitals represent a different population than those in a traditional birth hospital. The patients in a children's hospital NICU often have the most complex neonatal diagnoses and are cared for by various subspecialists. The Children's Hospitals Neonatal Consortium is a collaborative of more than 40 NICUs that collect data and perform quality improvement (QI) work across the United States and Canada. The collaborative's database provides an opportunity to benchmark clinical outcomes for this specialized population and to support the QI efforts. In this review, we summarize the success of individual collaborative QI projects focused on improving the care of the neonate in the perioperative period related to clinical team handoffs, postoperative hypothermia prevention, and improvement of postoperative pain management. The collaborative's experience can serve as a model for other national collaboratives seeking to support QI efforts.

Effect of Remimazolam on the Incidence of Intraoperative Hypothermia Compared with Inhalation Anesthetics in Patients Undergoing Endoscopic Nasal Surgery: A Prospective Randomized Controlled Trial

BACKGROUND

Remimazolam is an ultrashort-acting benzodiazepine that is increasingly used for its efficacy in anesthesia induction and maintenance. However, limited research has explored its impact on intraoperative hypothermia compared to that of traditional inhalation anesthetics. This study aimed to compare the incidence of hypothermia during endoscopic nasal surgery when using remimazolam for maintenance anesthesia versus using inhalation anesthetics.

METHODS

This prospective study included 70 patients who underwent endoscopic nasal surgery under general anesthesia. The patients were randomly assigned to one of two groups: the inhalation anesthetic (IA) group (n=35), in which desflurane and nitrous oxide were administered, and the remimazolam (R) group (n=35), in which remimazolam and remifentanil were administered for anesthesia maintenance. The primary outcome was the incidence of intraoperative hypothermia, defined as an esophageal temperature below 36 °C during anesthesia.

RESULTS

The incidence of intraoperative hypothermia was significantly higher in the R group than in the IA group (P = 0.014). Furthermore, the temperature at the end of the surgery was significantly lower in the R group than in the IA group (P = 0.006). Additionally, the use of warming devices after surgery was more frequent in the R group than in the IA group (P = 0.047).

CONCLUSIONS

These findings suggest that the use of remimazolam for maintenance anesthesia during endoscopic nasal surgery increases the risk of intraoperative hypothermia compared to the use of inhalation anesthetics. This highlights the importance of temperature monitoring in patients receiving remimazolam to minimize the adverse outcomes associated with hypothermia during surgery.

IMMOBILIZATION OF BLACK HOWLER MONKEYS (ALOUATTA PIGRA) USING BUTORPHANOL, AZAPERONE, MEDETOMIDINE IS SAFE AND EFFECTIVE FOR NONINVASIVE PROCEDURES

Administration of butorphanol, azaperone, and medetomidine (BAM) for immobilization of black howler monkeys (Alouatta pigra) has not been previously reported. In this observational study, 0.02 ml/kg of compounded BAM (butorphanol 27.3 mg/ml, azaperone 9.1 mg/ml, medetomidine 10.9 mg/ml) was administered IM in 10 captive black howler monkeys. Time to immobilization was recorded, an arterial blood gas performed, and at 5-min intervals, HR, RR, oscillometric arterial blood pressure, SPO2, and rectal temperature were measured. Naltrexone and atipamezole were administered IM at procedure completion and recovery times were recorded. If invasive procedures such as surgery were necessary and additional drugs needed, further data from that individual was removed from data analysis. Final BAM dosages were 0.55 ± 0.12 mg/kg butorphanol, 0.19 ± 0.04 mg/kg azaperone, and 0.22 ± 0.05 mg/kg medetomidine. Nine of 10 monkeys achieved sedation allowing for physical exam, venipuncture, and tuberculin skin testing within 4 ± 2 min. No monkeys reached a plane of immobilization allowing for intubation. Physiologic variables were acceptable for this species. Hypoxemia (SPO2 < 95%) was observed in three monkeys via pulse oximetry, and normoxemia was observed on arterial blood gas. Recovery was smooth and rapid. Therefore, BAM is a viable option for noninvasive procedures or as a premedication prior to induction of anesthesia in black howler monkeys.

Relationship between intraoperative hypothermia and hyperthermia with postoperative pulmonary infection and surgical site infection in major non-cardiac surgery

Background

Surgical patients often experience intraoperative hypothermia or hyperthermia. However, the relationship of intraoperative hypothermia and hyperthermia with postoperative pulmonary infection (PPI) and surgical site infection (SSI) is unclear. Here, we conducted a retrospective cohort study to address these issues.

Methods

Adult patients who underwent major non-cardiac surgery under general anesthesia were eligible for the study and were recruited. Three indices of core body temperature under hypothermia (<36°C) and hyperthermia (>37.3°C) were calculated as mentioned in the following: absolute value (0C), duration of exposure (min), and area under the curve (AUC,°C× min). The outcomes were in-hospital PPI and SSI. The risk-adjusted association of intraoperative hypothermia and hyperthermia with PPI and SSI was determined.

Results

The absolute value (the nadir value of hypothermia and the peak value of hyperthermia) was not associated with PPI and SSI. PPI was associated with (1) duration: hypothermia >90 min [adjusted odds ratio (aOR): 1.425, 95% confidence interval (CI): 1.131-1.796] and hyperthermia >75 min (aOR: 1.395, 95%CI: 1.208-1.612) and (2) AUC: hypothermia >3,198 (aOR: 1.390, 95%CI: 1.128-1.731) and hyperthermia >7,945 (aOR: 2.045, 95%CI: 1.138-3.676). SSI was associated with (1) duration: hypothermia > 195 min (aOR: 2.900, 95%CI: 1.703-4.937) and hyperthermia >75 min (aOR: 1.395, 95%CI: 1.208-1.612) and (2) AUC: hypothermia >6,946 (aOR: 2.665, 95%CI: 1.618-4.390), hyperthermia >7,945 (aOR: 2.619, 95%CI: 1.625-4.220). Interactions were not observed between hyperthermia and hypothermia on the outcomes.

Conclusions

It was observed that intraoperative hypothermia and hyperthermia are associated with postoperative pulmonary infection and surgical site infection in major non-cardiac surgery.

Exposure to postoperative hypothermia and its association with complications after major abdominal surgery: a retrospective cohort study

Purpose

Many patients who undergo major abdominal surgery experience inadvertent hypothermia during the perioperative period. This study aimed to identify risk factors related to postoperative hypothermia and their association with postoperative complications.

Methods

This retrospective cohort study used data from Seoul National University Bundang Hospital, a tertiary university medical center in South Korea, between January 1, 2018 and December 31, 2022. We included patients aged ≥18 years who underwent elective major abdominal surgery for more than 2 hours in the operating room. The patients were categorized into the hypothermia (body temperature <36.5℃) and non-hypothermia (body temperature ≥36.5℃) groups.

Results

The study sample comprised 30,194 patients, and we classified 21,293 and 8,901 into the hypothermic and non-hypothermic groups, respectively. Some factors associated with the occurrence of postoperative hypothermia included the type of surgery. In the multivariable logistic regression model, the incidence of postoperative complications was 9% higher in the hypothermia group than in the non-hypothermic group (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.01-1.19; P = 0.040). Among postoperative complications, the hypothermic group showed a 14% higher incidence of acute kidney injury (OR, 1.14; 95% CI, 1.04-1.25; P = 0.007) than the non-hypothermic group.

Conclusion

The appearance of postoperative hypothermia during the first 30 minutes of the recovery period was significantly associated with the appearance of postoperative complications, especially acute kidney injury. However, further studies are required to validate these findings.

A temperature-responsive intravenous needle that irreversibly softens on insertion

The high stiffness of intravenous needles can cause tissue injury and increase the risk of transmission of blood-borne pathogens through accidental needlesticks. Here we describe the development and performance of an intravenous needle whose stiffness and shape depend on body temperature. The needle is sufficiently stiff for insertion into soft tissue yet becomes irreversibly flexible after insertion, adapting to the shape of the blood vessel and reducing the risk of needlestick injury on removal, as we show in vein phantoms and ex vivo porcine tissue. In mice, the needles had similar fluid-delivery performance and caused substantially less inflammation than commercial devices for intravenous access of similar size. We also show that an intravenous needle integrated with a thin-film temperature sensor can monitor core body temperature in mice and detect fluid leakage in porcine tissue ex vivo. Temperature-responsive intravenous needles may improve patient care.

The impact of nursing sustainable prevention program on heat strain among agricultural elderly workers in the context of climate change

BACKGROUND

This study assesses a geriatric nursing-led sustainable heat prevention program for elderly agricultural workers. It targets those aged 60 and above, addressing the heightened risk of heat strain in the era of climate change.

METHODS

A community-based quasi-experimental design involved 120 elderly agricultural workers, divided into intervention and control groups. The program, spanning three months, included education on hydration, rest, protective clothing, and recognition of heat-related illnesses.

RESULTS

The intervention led by geriatric nursing professionals showed significant improvements in heat strain metrics. The Heat Strain Score Index (HSSI) and the Observational-Perceptual Heat Strain Risk Assessment (OPHSRA) Index indicated increased safety levels and reduced risk categories among participants.

CONCLUSIONS

The study demonstrates the effectiveness of a geriatric nursing-led, tailored prevention program in reducing heat strain among elderly agricultural workers. It highlights the crucial role of nursing in adapting healthcare practices to the challenges posed by climate change.

TRIAL REGISTRATION

ClinicalTrials.gov, ID NCT06192069 retrospectively registered.

Effects of Perioperative Hypothermia on Extubation, Recovery Time, and Postoperative Shivering in Breast Surgery

Women undergoing breast surgery seem to be under the risk for hypothermia (central body temperature <36°) due to the uncertainty caused by the preoperative preparation time and the variety of operations, leading to neglect of warming precautions. The study examines the perioperative hypothermia (PH) in breast surgery and the relationships between the depth of decrease in body temperature and individual or clinical variables. This prospective, cross-sectional, observational study includes 120 female patients 18-65 years of age who were given general anesthesia for breast surgery. The incidence of hypothermia was 68.1%. The given patients were discriminated as body temperature <36°, hypothermia was significantly related with lower weight, body mass index, American Society of Anesthesiology (ASA) score, baseline body temperatures, higher extubation, and recovery times. When patients' temperature decreases by >1 or 1.5°, lower age and longer durations of operation and anesthesia were also significant variables. The incidence of shivering is quite high at temperatures below 36°C or at 1 and 1.5°C reductions from baseline (72.7%, 84%, 94.1%, respectively). Body temperature changes of the patients had no effect on nausea-vomiting and pain scores. It turned out that the incidence of PH and shivering is high in women who underwent breast surgery. We think that the depth of decrease in body temperature should be taken into account when evaluating the predictors or clinical consequences of hypothermia, except for the 36°C limit for body temperature.

Core temperature following pre-hospital induction of anaesthesia in trauma patients

INTRODUCTION

Hypothermia is a well-recognised finding in trauma patients, which can occur even in warmer climates. It is an independent predictor of increased morbidity and mortality. It is associated with pre-hospital intubation, although the reasons for this are likely to be multifactorial. Core temperature drop after induction of anaesthesia is a well-known phenomenon in the context of elective surgery, and the mechanisms of this are well established.

METHODS

We conducted a prospective observational study to examine the behaviour of core temperature in patients undergoing pre-hospital anaesthesia for traumatic injuries.

RESULTS

Between 2017 and 2021 data were collected on 48 patients. The data from 40 of these were included in the final analysis.

DISCUSSION

Our data do not show a decrease in the core temperatures of patients who receive pre-hospital anaesthesia, unlike patients who are anaesthetised without pre-warming, in operating theatres. The lack of a change could relate to patient, anaesthetic or environmental factors.

Mechanisms of action behind the protective effects of proactive esophageal cooling during radiofrequency catheter ablation in the left atrium

Proactive esophageal cooling for the purpose of reducing the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation procedures is increasingly being used and has been Food and Drug Administration cleared as a protective strategy during left atrial RF ablation for the treatment of atrial fibrillation. In this review, we examine the evidence supporting the use of proactive esophageal cooling and the potential mechanisms of action that reduce the likelihood of atrioesophageal fistula (AEF) formation. Although the pathophysiology behind AEF formation after thermal injury from RF ablation is not well studied, a robust literature on fistula formation in other conditions (eg, Crohn disease, cancer, and trauma) exists and the relationship to AEF formation is investigated in this review. Likewise, we examine the abundant data in the surgical literature on burn and thermal injury progression as well as the acute and chronic mitigating effects of cooling. We discuss the relationship of these data and maladaptive healing mechanisms to the well-recognized postablation pathophysiological effects after RF ablation. Finally, we review additional important considerations such as patient selection, clinical workflow, and implementation strategies for proactive esophageal cooling.

Intraoperative hypothermia in patients with laparoscopic surgery: Influencing factors and prevention strategies

Background

Effective body temperature management is crucial for the favorable prognosis of patients undergoing surgery. The purpose of this study is to explore the risk factors of intraoperative hypothermia and to develop a risk prediction model to provide basis for clinical treatment.

Methods

Patients who underwent laparoscopic surgery in a tertiary hospital in China from February 1, 2023 to January 31, 2024 were included. The body temperature characteristics of patients in hypothermia group and non-hypothermia group were collected and evaluated. Univariate and Logistic regression analysis were used to evaluate the influencing factors. Based on the regression coefficients of risk factors, a risk prediction model of hypothermia was established. The model was assessed by Hosmer's Lemeshow (H- L) test and receiver working characteristic (ROC) curve.

Results

In 216 patients undergoing laparoscopic surgery, the incidence of hypothermia was 52.78 %. BMI≤23 kg/m2(OR = 2.061, 95%CI: 1.413-3.263), basal body temperature≤36.1 °C (OR = 3.715, 95%CI: 3.011-4.335), operating room temperature≤22 °C (OR = 2.481, 95%CI: 1.906-3.014), length of surgery≥120 min (OR = 2.228, 95%CI: 1.925-2.981) were the risk factors of hypothermia in patients undergoing laparoscopic surgery (all P < 0.05). The P value of H-L test was 0.098, the area under ROC curve and 95%CI were 0.806 (0.746-0.869). The sensitivity and specificity of the model in this study were good.

Conclusions

Patients undergoing laparoscopic surgery are at a high risk of developing hypothermia, a condition influenced by a multitude of factors. This model is designed to be integrated into clinical practice, enabling healthcare providers to identify patients with a higher risk and to implement targeted preventive measures.

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.

Fever in childbirth: a mini-review of epidural-related maternal fever

Fever during childbirth, which is often observed in clinical settings, is characterized by a temperature of 38°C or higher, and can occur due to infectious and non-infectious causes. A significant proportion of non-infectious causes are associated with epidural-related maternal fever during vaginal delivery. Therapeutic interventions are required because fever has adverse effects on both mother and newborn. Effective treatment options for ERMF are lacking. As it is difficult to distinguish it from intrauterine infections such as chorioamnionitis, antibiotic administration remains the only viable option. We mentioned the importance of interleukin-1 receptor antagonist in the sterile inflammatory fever pathway and the hormonal influence on temperature regulation during childbirth, an important factor in elucidating the pathophysiology of ERMF. This review spotlighted the etiology and management of ERMF, underscoring recent advancements in our understanding of hypothalamic involvement in thermoregulation and its link to sterile inflammation. We propose to deepen the understanding of ERMF within the broader context of autonomic neuroscience, aiming to foster the development of targeted therapies.

Antipyretic effect of inhaled Tetrastigma hemsleyanum polysaccharide on substance and energy metabolism in yeast-induced pyrexia mice via TLR4/NF-κb signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum Diels et Gilg, is one of the perennial evergreen plants with grass vine, which has obvious curative effect on severe infectious diseases. Although Tetrastigma hemleyanum has long been recognized for its capacity of antipyretic and antitoxic, its specific mechanism is unknown.

AIM OF THE STUDY

To evaluate the antipyretic effect of Tetrastigma hemleyanum polysaccharide (THP) on mice with dry yeast-induced fever, and to explore its specific antipyretic mechanism.

METHODS

In this study, THP was administered by aerosol in febrile mice. The rectal temperatures of treated animals were monitored at different time points. Histopathological evaluation and various inflammatory indexes were used to assess inflammatory damage. The concentration variations of the central neurotransmitter, endocrine system, substance and energy metabolism indicators were measured to explore the physiological mechanism. Quantitative real-time PCR, Western bolt and Immunohistochemistry were performed to identify the correlation between antipyretic and TLR4/NF-κB signaling pathway.

RESULTS

THP reduced the body temperature of febrile mice induced by dry yeast, as well as the levels of thermogenic cytokines and downregulated the contents of thermoregulatory mediators. THP alleviated the pathological damage of liver and hypothalamus caused by fever. In addition, THP decreased the secretion of thyroid hormone, substance and energy metabolism related indicators. Furthermore, THP significantly suppressed TLR4/NF-κB signaling pathway-related indicators.

CONCLUSIONS

In conclusion, our results suggest that inhaled THP exerts antipyretic effect by mediating the thermoregulatory mediator, decreasing the content of pyrogenic factors to lower the body temperature, and eventually restoring the high metabolic level in the body to normal via inhibiting TLR4/NF-κB signaling pathway. The study provides a reasonable pharmacodynamic basis for the treatment of polysaccharide in febrile-related diseases.

Intraoperative Patient Warming Instead of Gas on the Management of Postoperative Pain in Laparoscopic Colectomy and Cholecystectomy: A Randomized Controlled Trial

INTRODUCTION

Blurred lines remain in details of the association between patient warming with postoperative pain and a proper analgesic requirement. Therefore, the present study proposes to observe the effects of intraoperative patient warming and carbon dioxide insufflation duration in laparoscopic colectomy (LCol) and laparoscopic cholecystectomy (LChol) procedures on postoperative pain, analgesic requirements, and hemodynamics.

METHODS

The present study involved 80 cases aged 18-80 years with the American Society of Anesthesiologists I-III classification, possessing two initial groups primarily, one for LCol and one for LChol. Subsequently, each was divided into two through randomization for intraoperative warming. Postoperatively, pain perception, per se, was evaluated using the visual analog scale (VAS) score at the 30 minutes, 1st, 6th, 12th, and 24th hours, along with the impact of pain on hemodynamic parameters and side effects such as nausea/vomiting and the dosage of analgesics used.

RESULTS

Groups actively heated with warm air-blowing devices detected significantly higher intraoperative core and skin temperature measurements, and postoperative early pain perception was significantly lower in the warmed ones. Furthermore, a significant decrease in the VAS scores and the analgesic at the 12th and 24th hours compared to the first six hours was recognized between them.

CONCLUSION

Consequently, herewith, we postulate that so-called patient warming positively affects the VAS scores.

Clinical Efficacy of 10 Min of Active Prewarming for Preserving Patient Body Temperature during Percutaneous Nephrolithotomy: A Prospective Randomized Controlled Trial

Background: Percutaneous nephrolithotomy (PNL) poses a risk of hypothermia. Additionally, general anesthesia lowers the thresholds for shivering and vasoconstriction, which leads to dysfunction of central thermoregulation. Perioperative hypothermia is associated with adverse outcomes after surgery. In this study, we aimed to demonstrate that prewarming for 10 min can effectively prevent early hypothermia during PNL. Methods: A total of 68 patients scheduled for elective PNL were recruited to this study from January to June 2022, but two patients were excluded because of a change in the surgical plan. After randomization, patients in the prewarming group (n = 32) received warming using a forced-air warming device for 10 min in the preoperative area before being transferred to the operating room, while the controls (n = 34) did not. The incidence of hypothermia within the first hour after inducing general anesthesia was the primary outcome. Perioperative body temperatures and postoperative recovery findings were also evaluated. Results: Early intraoperative hypothermia decreased significantly more in the prewarming group than in the control group (9.4% vs. 41.2%, p = 0.003). Moreover, the net decrease in core body temperature during surgery was smaller in the prewarming group than in the control group (0.2 °C, vs. 0.5 °C, p = 0.003). In addition, the prewarmed patients had a lower incidence of postoperative shivering and a shorter post-anesthesia-care unit (PACU) stay (12.5% vs. 35.3%, p = 0.031; and 46 vs. 50 min, p = 0.038, respectively). Conclusions: Prewarming for 10 min decreased early hypothermia, preserved intraoperative body temperature, and improved postoperative recovery in the PACU.

Body Core Temperature Assessment in Emergency Care Departments

BACKGROUND

There is concern that the values provided by devices using infrared thermometry in emergency departments (EDs) do not reflect body core temperature accurately.

OBJECTIVES

Evaluation of three thermometers commonly used in the ED.

METHODS

Two infrared ear thermometers and an infrared forehead thermometer were evaluated using 1) the Voltcraft IRS-350 calibration device, 2) comparing temperature values to a rectal end-exercise temperature (T-RECT) of 38.1°C in 12 participants, and 3) comparing temperature values to rectal temperature in 133 ED patients.

RESULTS

Calibration across the human core temperature range revealed that the ear thermometers underestimated radiant temperature by 0.77 ± 0.39°C and 1.84 ± 0.26°C, respectively, whereas the forehead thermometer overestimated radiant temperature by 0.90 ± 0.51°C. After cycling exercise, all thermometers underestimated T-RECT (0.54 ± 0.27°C and 1.03 ± 0.48°C for the ear thermometers and 1.14 ± 0.38°C for the forehead thermometer). In the ED, the ear thermometers underestimated T-RECT by 0.31 ± 0.37°C and 0.46 ± 0.50°C, whereas the forehead thermometer exhibited a nonsignificant overestimation of 0.04 ± 0.46°C. If the threshold for fever in all systems had been set to 37.5°C instead of 38.0°C, the sensitivity and specificity of the systems for real fever (T-RECT ≥ 38°C) are, respectively, 71% and 96% (ear thermometer 1), 57% and 97% (ear thermometer 2), and 86% and 90% (forehead thermometer).

CONCLUSION

We conclude that the investigated thermometers are not reliable as devices to measure radiant temperature, cannot be used to assess body core temperature during exercise, but may be used as a screening device, with 37.5°C as a threshold for fever in emergency care settings.

Risk factors contributing to infection with SARS-CoV-2 are modulated by sex

Throughout the early stages of the COVID-19 pandemic in Mexico (August-December 2020), we closely followed a cohort of n = 100 healthcare workers. These workers were initially seronegative for Immunoglobulin G (IgG) antibodies against SARS-CoV-2, the virus that causes COVID-19, and maintained close contact with patients afflicted by the disease. We explored the database of demographic, physiological and laboratory parameters of the cohort recorded at baseline to identify potential risk factors for infection with SARS-CoV-2 at a follow-up evaluation six months later. Given that susceptibility to infection may be a systemic rather than a local property, we hypothesized that a multivariate statistical analysis, such as MANOVA, may be an appropriate statistical approach. Our results indicate that susceptibility to infection with SARS-CoV-2 is modulated by sex. For men, different physiological states appear to exist that predispose to or protect against infection, whereas for women, we did not find evidence for divergent physiological states. Intriguingly, male participants who remained uninfected throughout the six-month observation period, had values for mean arterial pressure and waist-to-hip ratio that exceeded the normative reference range. We hypothesize that certain risk factors that worsen the outcome of COVID-19 disease, such as being overweight or having high blood pressure, may instead offer some protection against infection with SARS-CoV-2.

Accuracy of a zero-heat-flux thermometer in cardiac surgery, a prospective, multicentre, method comparison study

Accurate measurement of core temperature is of utmost importance during on-pump cardiac surgery, for detection of hypothermia before cardiopulmonary bypass (CPB), guidance of temperature management on CPB, active rewarming on CPB and guidance of warming therapy after CPB. Most temperature measurement methods are known to become inaccurate during rapid changes in core temperature and suffer from delayed detection of temperature changes. Zero-heat-flux temperature (ZHF) measurement from the lateral forehead may be an alternative, non-invasive method quantifying the core temperature. A prospective, observational, multicentre study was conducted in one hundred patients scheduled for on-pump coronary artery bypass grafting. Core temperatures were measured every minute by two zero-heat-flux thermometer (SpotOn™) and a bladder thermometer and a pulmonary artery catheter (PAC) in the period after induction of anesthesia until CPB. Accuracy and precision of both methods were compared against core temperature measured in the pulmonary artery using the method of Bland and Altman. A high accuracy (around 0.1 °C) and a very good precision (Limits of agreement (LoA) - 0.6; 0.4 °C) were found between zero-heat-flux thermometer and core temperature measured by PAC. Among the two ZHF thermometers the bias was negligible (- 0.003 °C) with narrow LoA of - 0.42 °C and 0.41 °C. In contrast, bias between bladder temperature and PAC temperature was large (0.51 °C) with corresponding LoA of - 0.06 °C and 1.1 °C. ZHF thermometers are in contrast to bladder temperature a reliable core temperature monitor in cardiac surgery during the period after induction of anestesia until CPB. The zero-heat-flux method can provide clinicians reliably with continuous and non-invasive measurements of core temperature in normothermic and mild hypothermic temperature ranges and therefore can be helpful to guide temperature management.

Comparison of the incidence of inadvertent perioperative hypothermia between general anesthesia and interscalene brachial plexus block in shoulder arthroscopy: A randomized prospective study

INTRODUCTION

Inadvertent perioperative hypothermia (IPH), defined as core body temperature below 36°C, is associated with various complications. Shoulder arthroscopy is a risk factor of IPH. This study aimed to compare the incidence of IPH between general anesthesia (GA) and interscalene brachial plexus block (ISBPB) for shoulder arthroscopy.

METHOD

Patients scheduled for shoulder arthroscopy were prospectively enrolled and randomly assigned to GA or ISBPB groups. The body temperature of the patients was measured from baseline to the end of anesthesia and in the post-anesthetic care unit to compare the incidence of IPH.

RESULTS

Of the 114 patients initially identified, 80 were included in the study (GA = 40, ISBPB = 40). The incidence of IPH differed significantly between the groups, with GA at 52.5% and ISBPB at 30.0% (P = .04). Profound IPH (defined as < 35.0°C) occurred in 2 patients with GA. Upon arrival at the post-anesthesia care unit, the GA group exhibited a significantly lower mean body temperature (35.9 ± 0.6°C) than the ISBPB group (36.1 ± 0.2°C, P = .04).

CONCLUSION

The incidence of IPH in the GA group was higher than that in the ISBPB group during shoulder arthroscopy, suggesting that ISBPB may be a preferable anesthetic technique for reducing risk of IPH in such procedures.

Prevention of peri-interventional hypothermia during endoscopic retrograde cholangiopancreatography using a forced-air heating system

Background and study aims Perioperative hypothermia is associated with significant complications and can be prevented with forced-air heating systems (FAHS). Whether hypothermia occurs during prolonged endoscopic sedation is unclear and prevention measures are not addressed in endoscopic sedation guidelines. We hypothesized that hypothermia also occurs in a significant proportion of patients undergoing endoscopic interventions associated with longer sedation times such as endoscopic retrograde cholangiopancreaticography (ERCP), and that FAHS may prevent it. Patients and methods In this observational study, each patient received two consecutive ERCPs, the first ERCP following current standard of care without FAHS (SOC group) and a consecutive ERCP with FAHS (FAHS group). The primary endpoint was maximum body temperature difference during sedation. Results Twenty-four patients were included. Median (interquartile range) maximum body temperature difference was -0.9°C (-1.2; -0.4) in the SOC and -0.1°C (-0.2; 0) in the FAHS group ( P < 0.001). Median body temperature was lower in the SOC compared with the FAHS group after 20, 30, 40, and 50 minutes of sedation. A reduction in body temperature of > 1°C ( P < 0.001) and a reduction below 36°C ( P = 0.01) occurred more often in the SOC than in the FAHS group. FAHS was independently associated with reduced risk of hypothermia ( P = 0.006). More patients experienced freezing in the SOC group ( P = 0.004). Hemodynmaic and respiratory stability were comparable in both groups. Conclusions Hypothermia occurred in the majority of patients undergoing prolonged endoscopic sedation without active temperature control. FAHS was associated with higher temperature stability during sedation and better patient comfort.

Effect of 10 Minutes of Prewarming and Prewarmed Intravenous Fluid Administration on the Core Temperature of Patients Undergoing Transurethral Surgery under General Anesthesia

Background: Patients undergoing transurethral urologic procedures using bladder irrigation are at increased risk of perioperative hypothermia. Thirty minutes of prewarming prevents perioperative hypothermia. However, its routine application is impractical. We evaluated the effect of 10 minutes of prewarming combined with the intraoperative administration of warmed intravenous fluid on patients' core temperature. Methods: Fifty patients undergoing transurethral bladder or prostate resection under general anesthesia were included in this study and were randomly allocated to either the control group or the prewarming group. Patients in the prewarming group were warmed for 10 minutes before anesthesia induction with a forced-air warming device and received warmed intravenous fluid during operations. The patients in control group did not receive preoperative forced-air warming and were administered room-temperature fluid. Participants' core body temperature was measured on arrival at the preoperative holding area (T0), on entering the operating room, immediately after anesthesia induction, and in 10-minute intervals from then on until the end of the operation (Tend), on entering PACU, and in 10-minute intervals during the postanesthesia care unit stay. The groups' incidence of intraoperative hypothermia, change in core temperature (T0 - Tend), and postoperative thermal comfort were compared. Results: The incidence of hypothermia was 64% and 29% in the control group and prewarming group, respectively (P = 0.015). Change in core temperature was 0.93 ± 0.3 °C and 0.55 ± 0.4 °C in the control group and prewarming group, respectively (P = 0.0001). Thermal comfort was better in the prewarming group (P = 0.004). Conclusions: Ten minutes of prewarming combined with warmed intravenous fluid significantly decreased the incidence of intraoperative hypothermia and resulted in better thermal comfort in patients undergoing transurethral urologic surgery under general anesthesia.

Current State of Knowledge on the Definition, Pathophysiology, Etiology, Outcomes, and Management of Fever in the Intensive Care Unit

Fever-an elevated body temperature-is a prominent feature of a wide range of disease conditions and is a common finding in intensive care, affecting up to 70% of patients in the intensive care unit (ICU). The causes of fever in the ICU are multifactorial, and it can be due to a number of infective and noninfective etiologies. The production of fever represents a complex physiological, adaptive host response that is beneficial for host defense and survival but can be maladaptive and harmful if left unabated. Despite any cause, fever is associated with a wide range of cellular, local, and systemic effects, including multiorgan dysfunction, systemic inflammation, poor neurological recovery, and an increased risk of mortality. This narrative review presents the current state-of-the-art knowledge on the definition, pathophysiology, etiology, and outcomes of fever in the ICU and highlights evidence-based findings regarding the management of fever in the intensive care setting.

Survey of Transfer Learning Approaches in the Machine Learning of Digital Health Sensing Data

Machine learning and digital health sensing data have led to numerous research achievements aimed at improving digital health technology. However, using machine learning in digital health poses challenges related to data availability, such as incomplete, unstructured, and fragmented data, as well as issues related to data privacy, security, and data format standardization. Furthermore, there is a risk of bias and discrimination in machine learning models. Thus, developing an accurate prediction model from scratch can be an expensive and complicated task that often requires extensive experiments and complex computations. Transfer learning methods have emerged as a feasible solution to address these issues by transferring knowledge from a previously trained task to develop high-performance prediction models for a new task. This survey paper provides a comprehensive study of the effectiveness of transfer learning for digital health applications to enhance the accuracy and efficiency of diagnoses and prognoses, as well as to improve healthcare services. The first part of this survey paper presents and discusses the most common digital health sensing technologies as valuable data resources for machine learning applications, including transfer learning. The second part discusses the meaning of transfer learning, clarifying the categories and types of knowledge transfer. It also explains transfer learning methods and strategies, and their role in addressing the challenges in developing accurate machine learning models, specifically on digital health sensing data. These methods include feature extraction, fine-tuning, domain adaptation, multitask learning, federated learning, and few-/single-/zero-shot learning. This survey paper highlights the key features of each transfer learning method and strategy, and discusses the limitations and challenges of using transfer learning for digital health applications. Overall, this paper is a comprehensive survey of transfer learning methods on digital health sensing data which aims to inspire researchers to gain knowledge of transfer learning approaches and their applications in digital health, enhance the current transfer learning approaches in digital health, develop new transfer learning strategies to overcome the current limitations, and apply them to a variety of digital health technologies.

Temperature management in the intensive care unit: a practical survey from China

Introduction: Temperature management is an important aspect of the treatment of critically ill patients, but there are differences in the measurement and management of temperature in different Intensive Care Units (ICUs). The objective of this study was to understand the current situation of temperature measurement and management in ICUs in China, and to provide a basis for standardized temperature management in ICUs.Methods: A 20-question survey was used to gather information on temperature management strategies from ICUs across China. Data such as method and frequency of temperature measurement, management goals, cooling measures, and temperature management recommendations were collected.Results: A total of 425 questionnaires from unique ICUs were included in the study, with responses collected from all provinces and autonomous regions in China. Mercury thermometers were the most widely used measurement tool (82.39%) and the axilla was the most common measurement site (96.47%). There was considerable variability in the frequency of temperature measurement, the temperature at which intervention should begin, intervention duration, and temperature management goals. While there was no clearly preferred drug-based cooling method, the most widely used equipment-based cooling method was the ice blanket machine (93.18%). The most frequent recommendations for promoting temperature management were continuous monitoring and targeted management.Conclusion: Our investigation revealed a high level of variability in the methods of temperature measurement and management among ICUs in China. Since fever is a common clinical symptom in critically ill patients and can lead to prolonged ICU stays, we propose that standardized guidelines are urgently needed for the management of body temperature (BT) in these patients.

Relationship Between Types of Warming Devices and Surgical Site Infection in Patients Who Underwent Posterior Fusion Surgery Based on National Data

OBJECTIVE

Perioperative hypothermia can lead to various complications. Although various warming techniques have been used to prevent perioperative hypothermia, the effect of these techniques on surgical site infection (SSI) during posterior fusion surgery is unclear. The effects of warming devices on SSI rates were therefore analyzed using data complied by the Health Insurance and Review Assessment (HIRA) Service in Korea.

METHODS

This study included 5,406 patients in the HIRA Service database who underwent posterior fusion surgery during the years 2014, 2015, and 2017. Factors related to SSI in these patients, including warming devices, antibiotics, and transfusion, were analyzed.

RESULTS

The incidence of SSI was higher in patients who underwent forced air warming than in those who did not undergo active warming (odds ratio [OR], 1.73; p = 0.039), especially above 70 years old (OR, 4.11; p = 0.014). By contrast, the incidence of SSI was not significantly higher in patients who underwent device using conduction. Infection rates were higher in patients who received prophylactic antibiotics within 20 minutes before incision, than within 21 to 60 minutes (OR, 2.07; p = 0.001) and who received more blood transfusions (1 pint < volume ≤ 2 pint; OR, 1.75; p = 0.008, > 2 pint; OR, 2.73; p = 0.004).

CONCLUSION

SSI rates were higher in patients who underwent warming with forced air devices than with devices using conduction, as well as being higher in patients who older age, received blood transfusions and administered antibiotics within 20 minutes before incision. Devices using conduction have more advantages in preventing SSI than forced air warming device. In addition, the reduction of other risk factors for SSI may improve postoperative results.

Accuracy of non-invasive sensors measuring core body temperature in cardiac surgery ICU patients - results from a monocentric prospective observational study

PURPOSE

Temperature monitoring in the perioperative setting often represents a compromise between accuracy, invasiveness of probe placement, and patient comfort. Transcutaneous sensors using the Zero-Heat-Flux (ZHF) and Double-Sensor (DS) technology have been developed and evaluated in a variety of clinical settings. The present study is the first to compare the performance of both sensors simultaneously with temperature measured by a Swan-Ganz catheter (PAC) in patients admitted to the intensive care unit (ICU) after cardiac surgery.

METHODS

In this monocentric prospective observational study patients were postoperatively transferred to the ICU and both sensors were placed on the patients' foreheads. Core body temperature measured by intraoperatively placed PAC served as gold standard. Measurements were recorded at 5-minute intervals and up to 40 data sets per patient were recorded. Bland and Altman's method for repeated measurements was used to analyse agreement. Subgroup analyses for gender, body-mass-index, core temperature, airway status and different time intervals were performed. Lin's concordance correlation coefficient (LCCC) was calculated, as well as sensitivity and specificity for detecting hyperthermia (≥ 38 °C) and hypothermia (< 36 °C).

RESULTS

Over a period of six month, we collected 1600 sets of DS, ZHF, and PAC measurements, from a total of 40 patients. Bland-Altman analysis revealed a mean bias of -0.82 ± 1.27 °C (average ± 95% Limits-of-Agreement (LoA)) and - 0.54 ± 1.14 °C for DS and ZHF, respectively. The LCCC was 0.5 (DS) and 0.63 (ZHF). Mean bias was significantly higher in hyperthermic and hypothermic patients. Sensitivity and specificity were 0.12 / 0.99 (DS) and 0.35 / 1.0 (ZHF) for hyperthermia and 0.95 / 0.72 (DS) and 1.0 / 0.85 (ZHF) for hypothermia.

CONCLUSION

Core temperature was generally underestimated by the non-invasive approaches. In our study, ZHF outperformed DS. In terms of agreement, results for both sensors were outside the range that is considered clinically acceptable. Nevertheless, both sensors might be adequate to detect postoperative hypothermia reliably when more invasive methods are not available or appropriate.

TRIAL REGISTRATION

German Register of Clinical Trials (DRKS-ID: DRKS00027003), retrospectively registered 10/28/2021.