Intraoperative Hypothermia Research Articles

Effectiveness of Mild to Moderate Hypothermic Cardiopulmonary Bypass on Early Clinical Outcomes.

Background: Intraoperative hypothermia is an integral part of cardiopulmonary bypass (CPB), and a precise degree of hypothermia may improve the early clinical outcomes of cardiac surgery. Presently, there is no agreement on an accurate, advantageous temperature range for routine use in CPB. To address this issue, we conducted a retrospective observational study to compare the effects of different hypothermic temperature ranges on primary (inotropic support, blood loss, and platelet count) and secondary (ventilation support and in-hospital stay) outcomes in patients undergoing elective cardiac surgery. Methods: Data were retrieved from the medical database of the Cardiovascular Surgery Department, King Edward Medical University, Lahore-Pakistan (a tertiary care hospital), dating from February 2015 to December 2017. Patients were divided into mild (34 °C to 36 °C), intermediate (31 °C to 33 °C), or moderate (28 °C to 30 °C) hypothermic groups. Results: Out of 275 patients, 245 (89.09%) fit the inclusion criteria. The cohort with mild hypothermic CPB temperatures presented better clinical outcomes in terms of requiring less inotropic support, less blood loss, fewer blood transfusions, improved platelet counts, shorter in-hospital stays, and required less ventilation support, when compared with other hypothermic groups. Conclusions: Mild hypothermic CPB (34 °C to 36 °C) may produce better clinical outcomes for cardiac surgery and improve the quality of health of cardiac patients.

Perioperative Prewarming: Heat Transfer and Physiology.

To appreciate the strategy of prewarming, perioperative personnel should have a basic understanding of the physics of heat transfer and the thermoregulatory pathophysiology of anesthesia. The dominant cause of postinduction hypothermia is anesthesia-related redistribution of heat within the body; the role of cutaneous heat loss is minimal. Physiologic thermoregulatory system changes that occur in response to anesthesia make it almost impossible to reverse intraoperative hypothermia. However, prewarming is an effective strategy to prevent postinduction hypothermia from redistribution because it creates a temporary excess of heat in the body's peripheral thermal compartment. Perioperative nurses should implement active and passive prewarming strategies in accordance with the warming devices at their facility and available time. This article focuses on two major topics necessary to understand prewarming: the effect of anesthesia on postinduction thermoregulation and thermodynamic conditions that successful treatment strategies must exploit to produce desired outcomes.

Intraoperative hypothermia in the neonate population: risk factors, outcomes, and typical patterns

The risk factors, outcomes, and typical patterns of intraoperative hypothermia were studied in neonates to better guide the application of insulation measures in the operating room. This retrospective study enrolled 401 neonates undergoing surgery under general anaesthesia with tracheal intubation, including abdominal surgery, thoracic surgery, brain surgery, and others. The study collected basic characteristics, such as age, sex, weight, birth weight, gestational week, primary diagnosis and American Society of Anaesthesiologists (ASA) grade. Perioperative data included preoperative body temperature, length of hospital stay, length of intensive care unit (ICU) stay, intubation time, postoperative bleeding, postoperative pneumonia, postoperative death, and total cost of hospitalization. Intraoperative data included surgical procedures, anaesthesia duration, operation duration, blood transfusion, fluid or albumin infusion, and application of vasoactive drugs. The incidence of intraoperative hypothermia (< 36 °C) was 81.05%. Compared to normothermic patients, gestational week (OR 0.717; 95% CI 0.577–0.890; P = 0.003), preoperative temperature (OR 0.228; 95% CI 0.091–0.571; P = 0.002), duration of anaesthesia (OR 1.052; 95% CI 1.027–1.077; P < 0.001), and type of surgery (OR 2.725; 95% CI 1.292–5.747; P = 0.008) were associated with the risk of intraoperative hypothermia. Patients with hypothermia had longer length of ICU stay (P = 0.001), longer length of hospital stay (P < 0.001), and higher hospital costs (P < 0.001). But there were no association between clinical outcomes and intraoperative hypothermia in the multivariable regression adjusted analysis. The lowest point of intraoperative body temperature was approximately 1 h 30 min. Then, the body temperature of patients successively entered a short plateau phase and a period of slow ascent. The greatest decrease in body temperatures occurred in preterm babies and neonates with preoperative hypothermia. The lowest core temperatures that occurred in neonates with preoperative hypothermia was lower than 35 °C. This study shows that there is a high incidence of intraoperative hypothermia in the neonate population. The intraoperative body temperature of neonates dropped to the lowest point in 1–1.5 h. The greatest decrease in core temperatures occurred in preterm babies and neonates with lower preoperative temperature.

An Overview of the Implications for Perianesthesia Nurses in terms of Intraoperative Changes in Temperature and Factors Associated with Unintentional Postoperative Hypothermia.

Patients undergo surgery and anaesthesia on a daily basis across the United States and throughout the world. A major source of worry for these patients continues to be inadvertent hypothermia, once core temperature <36°C (96.8°F). Despite well-documented adverse physiological consequences, anaesthesia nurses continue to have a difficult task in keeping patient warmth pre-/peri-/post-surgical procedure. Thermostasis within postoperative patient necessitates the collaboration of many individuals. In order to provide safe and high-quality treatment, it is essential to use the most up-to-date data to guide therapeutic procedures targeted at achieving balance body temperature in surgical patients. Providing a review of the physiology of perioperative temperature variations and the comorbidities linked with accidental intraoperative hypothermia, this article will also provide preventive and treatment methods.

Challenging dogma about perioperative warming during non-cardiac surgery

Perioperative hypothermia—which is most frequently defined as a body temperature less than 36°C—causes sympathetic stimulation and increases myocardial oxygen consumption, which is thought to contribute to myocardial injury.1 Because cellular functions are temperature-dependent, it is unsurprising that randomised trials report that hypothermia causes perioperative coagulopathy, transfusion, infection, and increases hospital stay durations.2 Given that general and neuraxial anaesthesia impair thermoregulation, measures to prevent intraoperative hypothermia are common, although the evidence supporting them is scarce.

Aggressive intraoperative warming versus routine thermal management during non-cardiac surgery (PROTECT): a multicentre, parallel group, superiority trial

Moderate intraoperative hypothermia promotes myocardial injury, surgical site infections, and blood loss. Whether aggressive warming to a truly normothermic temperature near 37°C improves outcomes remains unknown. We aimed to test the hypothesis that aggressive intraoperative warming reduces major perioperative complications. In this multicentre, parallel group, superiority trial, patients at 12 sites in China and at the Cleveland Clinic in the USA were randomly assigned (1:1) to receive either aggressive warming to a target core temperature of 37°C (aggressively warmed group) or routine thermal management to a target of 35·5°C (routine thermal management group) during non-cardiac surgery. Randomisation was stratified by site, with computer-generated, randomly sized blocks. Eligible patients (aged ≥45 years) had at least one cardiovascular risk factor, were scheduled for inpatient non-cardiac surgery expected to last 2-6 h with general anaesthesia, and were expected to have at least half of the anterior skin surface available for warming. Patients requiring dialysis and those with a body-mass index exceeding 30 kg/m2 were excluded. The primary outcome was a composite of myocardial injury (troponin elevation, apparently of ischaemic origin), non-fatal cardiac arrest, and all-cause mortality within 30 days of surgery, as assessed in the modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03111875. Between March 27, 2017, and March 16, 2021, 5056 participants were enrolled, of whom 5013 were included in the intention-to-treat population (2507 in the aggressively warmed group and 2506 in the routine thermal management group). Patients assigned to aggressive warming had a mean final intraoperative core temperature of 37·1°C (SD 0·3) whereas the routine thermal management group averaged 35·6°C (SD 0·3). At least one of the primary outcome components (myocardial injury after non-cardiac surgery, cardiac arrest, or mortality) occurred in 246 (9·9%) of 2497 patients in the aggressively warmed group and in 239 (9·6%) of 2490 patients in the routine thermal management group. The common effect relative risk of aggressive versus routine thermal management was an estimated 1·04 (95% CI 0·87-1·24, p=0·69). There were 39 adverse events in patients assigned to aggressive warming (17 of which were serious) and 54 in those assigned to routine thermal management (30 of which were serious). One serious adverse event, in an aggressively warmed patient, was deemed to be possibly related to thermal management. The incidence of a 30-day composite of major cardiovascular outcomes did not differ significantly in patients randomised to 35·5°C and to 37°C. At least over a 1·5°C range from very mild hypothermia to full normothermia, there was no evidence that any substantive outcome varied. Keeping core temperature at least 35·5°C in surgical patients appears sufficient. 3M and the Health and Medical Research Fund, Food and Health Bureau, Hong Kong. For the Chinese translation of the abstract see Supplementary Materials section.

The effect of warm and humidified gas insufflation in gynecological laparoscopy on maintenance of body temperature: a prospective randomized controlled multi-arm trial

BackgroundHypothermia is defined as a decrease in body core temperature to below 36 °C. If intraoperative heat-preserving measures are omitted, a patient’s temperature will fall by 1 – 2 °C. Even mild forms of intraoperative hypothermia can lead to a marked increase in morbidity and mortality. Using warm and humidified gas insufflation in laparoscopy may help in the maintenance of intraoperative body temperature.MethodsIn this prospective randomized controlled study, we investigated effects of temperature and humidity of the insufflation gas on intra- and postoperative temperature management. 150 patients undergoing gynecologic laparoscopic surgery were randomly assigned to either insufflation with non-warmed, non-humidified CO2 with forced air warming blanket (AIR), humidified warm gas without forced air warming blanket (HUMI) or humidified warm gas combined with forced air warming blanket (HUMI+). We hypothesized that the use of warmed laparoscopic gas would have benefits in the maintenance of body temperature and reduce the occurrence of hypothermia.ResultsThe use of warm and humidified gas insufflation alone led to more hypothermia episodes with longer duration and longer recovery times as well as significantly lower core body temperature compared to the other two groups. In the comparison of the AIR group and HUMI + group, HUMI + patients had a significantly higher body temperature at arrival at the PACU (Post Anaesthesia Care Unit), had the least occurrence of hypothermia and suffered from less shivering.ConclusionThe use of warm and humidified gas insufflation alone does not sufficiently warm the patients. The optimal temperature management is achieved in the combination of external forced air warming and insufflation of warm and humidified laparoscopy gas.

A Systematic Review and Meta-Analysis of Risk Factors for Unplanned Intraoperative Hypothermia Among Adult Surgical Patients

PurposeUnplanned intraoperative hypothermia (UIH) is a frequent but preventable complication of surgery. Accurate identification of UIH risk factors allows nurses to minimize its negative outcomes. This study aimed to investigate the risk factors for UIH in adult surgical patients. DesignSystematic review and meta-analysis MethodsWe comprehensively searched PubMed, Cochrane Central Register of Controlled Trials, Web of Science, Ovid Embase, and ClinicalTrials.gov from their inception until December 31, 2020 to identify available, related studies in English. Two authors independently extracted data from these studies. Data analysis was performed using Review Manager Version 5.3. ResultsThis meta-analysis included 12 studies involving 15,010 patients. The combined results showed that age [mean difference (MD) = 4.85, P < .0001; I2 = 94%], body mass index (MD = − 0.76, P = .001; I2 = 59%), ambient temperature [odds ratio (OR) = 0.82, P < .001; I2 = 54%], preoperative systolic blood pressure (MD = −14.68, P < .00001; I2 = 30%), preoperative heart rate (MD = − 13.25, P < .00001; I2 = 0%), duration of anesthesia (>2 h; OR = 2.67, P < .001; I2 = 0%), and intravenous fluid administration >1,000 mL (OR = 2.02, P = .01; I2 = 77%) were significantly associated with a higher risk of UIH. ConclusionsOur study demonstrated that various risk factors contribute to the development of UIH. Perioperative nurses should understand these risk factors in order to apply evidence-based procedures and improve patient outcomes. Due to the substantial clinical heterogeneity across studies, further studies are needed to verify these findings.

A Pilot Quality Improvement Project to Reduce Intraoperative MRI Hypothermia in Neurosurgical Patients.

Introduction:Intraoperative hypothermia increases patient morbidity, including bleeding and infection risk. Neurosurgical intraoperative magnetic resonance imaging (iMRI) can lead to hypothermia from patient exposure and low ambient temperature in the MRI suite. This quality improvement project aimed to reduce the risk of hypothermia during pediatric neurosurgery laser ablation procedures with iMRI. The primary aim was to increase the mean lowest core temperature in pediatric patients with epilepsy during iMRI procedures by 1 °C from a baseline mean lowest core temperature of 34.2 ± 1.2 °C within 10 months and sustain for 10 months.Methods:This report is a single-institution quality improvement project from March 2019 to June 2021, with 21 patients treated at a pediatric hospital. After identifying key drivers, temperature-warming interventions were instituted to decrease hypothermia among patients undergoing iMRI during neurosurgery procedures. A multidisciplinary team of physicians, nurses, and MRI technologists convened for huddles before each case. Interventions included prewarmed operating rooms (ORs), blanket coverings, MRI table and room; forced-air blanket warming, temperature monitoring in the OR and iMRI environments; and the MRI fan turned off.Results:Data were analyzed for five patients before and nine patients after the institution of the temperature-warming elements. The sustainment period included 15 patients. The mean lowest intraoperative temperature rose from 34.2 ± 1.3 °C in the preintervention period to 35.5 ± 0.6 °C in sustainment (P = 0.004).Conclusion:Hybrid OR and MRI procedures increase hypothermia risk, which increases patient morbidity. Implementation of a multidisciplinary, multi-item strategy for patient warming mitigates the risk.

Impact of the Hormonal Status in Women on Intraoperative Hypothermia during Laparoscopic Gynecologic Surgery when Considering the Fresh Gas Flow Rate: A Retrospective Study.

Previous studies reported the impact of intrinsic and extrinsic factors on intraoperative hypothermia. However, no clinical study to date has considered the effects of both the phase of the menstrual cycle (an intrinsic factor) and the fresh gas flow rate (FGF) during anesthesia (an extrinsic factor) on the core body temperature and intraoperative hypothermia. This study is aimed at investigatig the effect of the menstrual cycle phase on intraoperative hypothermia when considering the FGF in patients who underwent laparoscopic gynecologic surgery. This study included 667 women aged 19-65 years with menstruation cycles and menopause. The patients were divided into the follicular, luteal, and menopause groups. The primary outcome was the correlations of hormonal status with intraoperative hypothermia. Secondary outcomes included the incidence of intraoperative hypothermia, time to onset of hypothermia, incidence of shivering after anesthesia, and frequency of antishivering drug use in the three groups and risk factors for hypothermia. Overall, the hypothermia incidence was the lowest and the time to onset of hypothermia was the longest in the luteal phase group. At a high FGF, the incidence of hypothermia in the luteal phase group was lower than that in the other two groups (P < 0.05). At a low FGF, the time to onset of hypothermia in the luteal phase group was longer than that in the other two groups (P < 0.05). The female hormonal status had weak positive correlations with hypothermia at low and high FGF rates. A high FGF in univariate and multivariate analyses, follicular phase and menopause in multivariate analysis, and estradiol and progesterone levels in univariate analysis were risk factors for hypothermia. When considering the FGF, the luteal phase is associated with better outcomes concerning intraoperative hypothermia.

Magnitude and associated factors of intra-operative hypothermia among pediatric patients undergoing elective surgery: A multi-center cross-sectional study

BackgroundHypothermia is a core body temperature of less than 36 c0 that could increase perioperative morbidity & mortality of pediatric patients operated under general anesthesia. This study aimed to assess the magnitude and associated factors of intra-operative hypothermia among pediatric patients undergoing elective surgery. MethodInstitutional based cross-sectional study was conducted on 339 pediatric patients undergoing elective surgery in referral hospitals of Addis Ababa, Ethiopia. Data were collected using a structured questionnaire. Descriptive statics were expressed in percentage and presented with tables. Both Bivariable and multivariable logistic analysis was done to identify factors associated with intra-operative hypothermia among pediatric patients undergoing elective surgery. P < 0.05 with 95% CI was set as statistical significance. ResultThe magnitude of intra-operative hypothermia in this study was 39.8 [95% CI= (34.5–45.1)]. Multivariable logistic analyses showed that ambient temperature less than 26c0 [AOR = 6; 95%CI=(2.859–13.23)], volume of fluid administered greater than half a liter [AOR = 3.6; 95%CI=(1.83–7.23)], Patients who were received un-warm fluid [AOR = 2.2; 95%CI=(1.28–4.04)] and duration of surgery and anesthesia greater than 120 min [AOR = 3.4; 95%CI=(1.29–8.79)] and [AOR = 3.8; 95%CI=(1.25–11.53)] respectively were factors significantly associated with intra-operative hypothermia. ConclusionThe magnitude of intra-operative hypothermia in this study was high. So, adherence must be done in the prevention of intraoperative hypothermia by health professionals such as increasing operation room temperature, warming administered fluid, optimal fluid administration, and reduction of the duration of surgery and anesthesia.

Effect of active forced air warming during the first hour after anesthesia induction and intraoperation avoids hypothermia in elderly patients

BackgroundThe study aimed at exploring an optimal temperature model of forced air warming during the first hour after induction and intraoperation to prevent hyperthermia for elderly patients undergoing laparoscopic abdominal surgery.MethodsThere were 218 patients that were randomly divided into 3 groups warmed with a forced-air warmer during surgery: Group L (intraoperative warming set to 38 °C, n = 63), Group H (intraoperative warming set to 42 °C, n = 65) and Group LH (intraoperative warming set to 42 °C for the first hour then set to 38 °C, n = 65). Core temperature in the preoperative room and PACU was measured by a tympanic membrane thermometer and in the operation room, a nasopharyngeal temperature probe was recorded. The rate of perioperative hypothermia, defined as a reduction in body temperature to < 36 °C was recorded as the primary outcome. Intraoperative anesthetic dosage, recovery time, adverse events, thermal comfort and satisfaction score were measured as secondary outcome.ResultsThe incidence of intraoperative and postoperative hypothermia was significantly lower in Group LH and Group H than Group L (18.75 and 15.62% vs 44.44%, P<0.001; 4.69 and 4.69% vs 20.63%, P<.05). Anesthetic dosage of rocuronium was lower in Group L than other two groups, with the opposite result of recovery time. The number of patients with shivering was higher in Group L but sweating was higher in Group H. Both of the thermal comfort and satisfaction score was highest in Group LH.ConclusionA temperature pattern of forced air warming set at 42 °C during the first hour after anesthesia induction and maintained with 38 °C was a suitable choice for elderly patients undergoing laparoscopic abdominal surgery lasting for more than 120 min.Trial registrationChictr.org.cn ChiCTR-2,100,053,211.

Effects of Heated Tumescence Solution in Bitches after Unilateral Mastectomy

Background: Mammary tumors, for which mastectomy is the main treatment, are the most common neoplasms in bitches. Mastectomy is painful and, in order to reduce the pain stimulus in the transoperative period, tumescent local anesthesia is associated with general inhalation anesthesia. However, despite the numerous benefits of tumescence, intraoperative hypothermia is the most common complication. In Medicine, especially in plastic and dermatological surgery, it is common to use a heated tumescence solution to prevent intraoperative hypothermia; however, in Veterinary medicine, no previous study has examined the advantages and disadvantages of using heated tumescence solution. Thus, this study aimed to investigate the transanesthetic cardiorespiratory effects of heated tumescence solution in bitches submitted to radical unilateral mastectomy.Materials, Methods &amp; Results: Eight animals were treated with 0.1% lidocaine solution, warmed to 37-42°C, using a Klein’s cannula for administration. Chlorpromazine (0.3 mg/kg) and meperidine (3 mg/kg) were used as pre-anesthetic medication intramuscularly, and induction was performed with intravenous propofol and maintenance with isoflurane. The data collection times were as follows: 15 min after starting isoflurane administration (M1), 5 min after tumescence (M2), after beginning of surgical incision (M3), during breast pullout (M4), after clamping of the superficial caudal epigastric vein, and artery (M5), after the beginning of the approximation of the subcutaneous tissue (M6), after the beginning of the intradermal suture (M7), and at the end of the surgical procedure (Mfinal). The heart (HR) and respiratory (ƒ) rates, mean arterial pressure (MAP), end-tidal CO2 concentration (EtCO2), expired isoflurane concentration (EtISO), and rectal temperature (RT) were measured. The HR, ƒ, and EtCO2levels did not differ statistically. The mean EtISO presented in M2 (1.16 ± 0.41) was significantly lower than that in M3 (1.39 ± 0.40) and M4 (1.49 ± 0.49).Discussion: In the HR analysis, it was found that during all evaluation moments, the means remained within the reference range for the species. Moreover, the values during the breast pullout (M4) did not exceed 20% of those presented minutes before the beginning of the surgery (M2), which was indicative of analgesic rescue, suggesting that the animals did not experience pain. Hypoventilation resulted in an increase in EtCO2 values. Thus, it can be said that in this study, there was no respiratory depression during the transoperative period, as the values of the variables ƒ and EtCO2 were within the reference for the species. With regard to the EtISO variable, there was no reduction in the MAC of isoflurane with the use of heated tumescence solution, as reported by some authors (EtISO 0.8%). However, the EtISO values presented here are close to those found in the literature during breast pullout (EtISO between 1.3% and 1.52%), with the use of refrigerated tumescence solution. In addition, the values shown in M4 are within the equivalent of 1 MAC (1.41%) of isoflurane, proving that heated tumescent local anesthesia is a safe technique and an excellent adjunct to inhalation anesthesia, as it provides intraoperative analgesia. Therefore, heated tumescence solution is safe and an excellent adjuvant in general inhalational anesthesia for radical unilateral mastectomy as it did not increase inhaled anesthetic consumption during surgery.Keywords: tumescent local anesthesia, lidocaine, dogs, inhalation anesthesia, mammary tumors.

Попередження інтраопераційної ненавмисної гіпотермії у пацієнтів із політравмою

Актуальність. Ненавмисна гіпотермія розвивається спонтанно як наслідок травми, хірургічного втручання та наркозу в результаті порушення відповідності теплопродукції тепловтрат і пригнічення компенсаторної терморегуляційної відповіді. Мета: вивчити ефективність способу корекції інтраопераційної ненавмисної гіпотермії з використанням системи конвекційного обігріву в пацієнтів із політравмою. Матеріали та методи. Обстежено 20 пацієнтів із політравмою, яким проводились ургентні оперативні втручання. Пацієнти були розділені на 2 групи: I — основна група (n = 10), в якій інтраопераційно проводилося активне зігрівання системою конвекційного обігріву WarmAir 135 (CSZ) з використанням ковдр для зігрівання в умовах операційної; II — контрольна група (n = 10) без використання конвекційного зігрівання. Вивчалася температура ядра тіла (Тсо): початково, через 30, 60 хвилин і наприкінці операції. Розраховувалися наступні показники: мінімальна (Тмін.) і максимальна (Тмакс.) температура, середня температура (Тср.), температурний діапазон (Тдіап. = Tмакс. – Тмін.). Результати. У всіх пацієнтів із політравмою та проведенням ургентних хірургічних втручань відзначається розвиток клінічно значущої ненавмисної гіпотермії. На етапі 60 хвилин інтраопераційного періоду Тсо була вірогідно вище в I групі (35,38 ± 0,28 °С) порівняно з пацієнтами II групи (34,70 ± 0,39 °С) (p &lt; 0,05). Виявлено вірогідно вищий рівень середньої Тсо в I групі (35,53 ± 0,66 °С) порівняно з II групою (34,67 ± 1,74 °С) пацієнтів (p &lt; 0,05). Діапазон температур, який являє собою різницю максимальної та мінімальної Тсо, був вірогідно нижче в I групі пацієнтів (1,36 ± 0,74 °С) порівняно з II групою (4,55 ± 1,11 °С) (p &lt; 0,05). Висновки. Використання в комплексі інтенсивної терапії конвекційної системи зігрівання хоча й не дозволяє досягти вихідних значень Тсо, але попереджає прогресування поглиблення гіпотермії, ефективно забезпечуючи підтримку температурного гомеостазу у критичних пацієнтів із політравмою.

The Effects of Intraoperative Hypothermia on Postoperative Cognitive Function in the Rat Hippocampus and Its Possible Mechanisms.

Intraoperative hypothermia is a common complication during operations and is associated with several adverse events. Postoperative cognitive dysfunction (POCD) and its adverse consequences have drawn increasing attention in recent years. There are currently no relevant studies investigating the correlation between intraoperative hypothermia and POCD. The aim of this study was to assess the effects of intraoperative hypothermia on postoperative cognitive function in rats undergoing exploratory laparotomies and to investigate the possible related mechanisms. We used the Y-maze and Morris Water Maze (MWM) tests to assess the rats’ postoperative spatial working memory, spatial learning, and memory. The morphological changes in hippocampal neurons were examined by haematoxylin-eosin (HE) staining and hippocampal synaptic plasticity-related protein expression. Activity-regulated cytoskeletal-associated protein (Arc), cyclic adenosine monophosphate-response element-binding protein (CREB), S133-phosphorylated CREB (p-CREB [S133]), α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor 1 (AMPAR1), and S831-phosphorylated AMPAR1 (p-AMPAR1 [S831]) were evaluated by Western blotting. Our results suggest a correlation between intraoperative hypothermia and POCD in rats and that intraoperative hypothermia may lead to POCD regarding impairments in spatial working memory, spatial learning, and memory. POCD induced by intraoperative hypothermia might be due to hippocampal neurons damage and decreased expression of synaptic plasticity-related proteins Arc, p-CREB (S133), and p-AMPAR1 (S831).

Risk Nomogram Does Not Predict Anastomotic Leakage After Colon Surgery Accurately: Results of the Multi-center LekCheck Study

PurposeAnastomotic leakage (AL) is a dreaded complication after colorectal surgery. Preoperatively identifying high-risk patients can help to reduce the incidence of this complication. For this reason, AL risk nomograms have been developed. The objective of this study was to test the AL risk nomogram developed by Frasson, et al. for validity and to identify risk-factors for AL. MethodsFrom the international multi-center LekCheck study database, patients who underwent colonic surgery with the formation of an anastomosis were included. Data were prospectively collected between 2016 and 2019 at 14 hospitals. Univariate and multivariable regression analyses, and area under receiver operating characteristic curve analysis (AUROC) were performed. ResultsA total of 643 patients were included. The median age was 70 years and 51% were male. The majority underwent surgery for malignancies (80.7%). The overall AL rate was 9.2%. The risk nomogram was not predictive for AL in the population tested (AUROC 0.572). Low preoperative haemoglobin (p = 0.006), intraoperative hypothermia (p = 0.02), contamination of the operative field (p = 0.004), and use of epidural analgesia (p = 0.02) were independent risk-factors for AL. ConclusionThe AL risk nomogram could not be validated using the international LekCheck study database. In the future, intraoperative predictive factors for AL, as identified in this study, should also be included in AL risk predictors.

Implementation of multi-mode nursing insulation program for patients receiving surgery for spine tumor: a propensity score-matched analysis

BackgroundSpinal tumor surgery usually involved long operation time, large area of soft tissue resection and long wound, and was prone to hypothermia during the operation. Therefore, actively promoting insulation and optimizing the intraoperative insulation program have great potential in reducing the incidence of hypothermia and reducing the incidence of postoperative complications. In this study, we compared patients who did not implement multi-mode nursing insulation program (MNIP) with those who implemented MNIP, observing and comparing clinical outcomes, and complications in both groups, with the aim of developing an optimal management plan for the preoperative, intraoperative, and postoperative periods, respectively.MethodsWe selected 2 periods of 1 year, before (n = 120 patients) and after MINP implementation (n = 120 patients). Data were collected on patient demographics, operative, perioperative details, temperature changes, anesthesia recovery effect, incidence of postoperative wound infection, length of hospital stay and complications. PS analyses were used for dealing with confounding bias in this retrospective observational study.ResultsAfter PS matching, the outcomes of 120 well-balanced pairs of patients were compared (No-MNIP vs MNIP). There was no significant difference concerning the satisfaction survey. The results indicated that the MNIP had better insulation effect at 90 min, 120 min, 150 min after anesthesia induction and after surgery. There were 16 cases of complications in the No-MNIP group and 5 cases in the MNIP group postoperative, which have significant statistical difference.ConclusionIn this study, the incidence of intraoperative hypothermia was effectively reduced by adopting the multi-mode insulation scheme, thus reducing the incidence of incision infection and shortening the length of hospital stay of patients.

Clinical efficacy of short-term prewarming in elderly and adult patients: A prospective observational study.

Background: Short-term prewarming effectively reduces intraoperative hypothermia in adult patients. However, few data exist regarding its efficacy in elderly patients. Elderly people have a reduced ability to regulate their body temperature, which affects the efficacy of prewarming. This study aimed to compare the clinical efficacy of short-term pre-warming in elderly patients with that in adult patients.Methods: We enrolled 25 adult (20-50 years) and 25 elderly (> 65 years) patients scheduled for ureteroscopic stone surgery under general anaesthesia. All patients received preanaesthetic forced-air warming for 20 min. The core temperature was measured using an infrared tympanic thermometer during awakening and nasopharyngeal thermistors during anaesthesia. Incidence and severity of intraoperative hypothermia (< 36°C) was compared. Postoperative shivering and number of patients requiring active warming in the post-anaesthesia care unit were also assessed.Results: Intraoperative hypothermia was more frequent in elderly than in adult patients (58.3% vs. 12.0%; relative risk 2.6; 95% confidence interval 1.5 to 4.6; effect size h = 1.010; p = 0.001). The severity of intraoperative hypothermia showed a significant intergroup difference (p = 0.002). Postoperative shivering was more frequent in elderly than in adult patients (33.3% vs. 8.0%, p = 0.037). A greater number of elderly patients in the post-anaesthesia care unit required active warming (33.3% vs. 8.0%, p = 0.037).Conclusions: The effects of short-term prewarming on the prevention of hypothermia and maintenance of perioperative normothermia are not the same in the elderly and adult patients.

Feasibility study of a novel rectal cooling system for hypothermic radical prostatectomy in a swine model.

Thermal damage and inflammatory responses of the sphincter and neurovascular bundles (NVBs) are responsible for post-prostatectomy incontinence and erectile dysfunction. Intraoperative hypothermia in the pelvic cavity may reduce the occurrence of these complications. We evaluated the feasibility of a novel rectal cooling system using an animal model. A novel rectal cooling system consisting of a cooling console and a multi-lumen rectal balloon was developed. We conducted animal tests on male pigs to evaluate the efficacy and safety of the system. The primary endpoint was to maintain the temperature of the NVBs at 25℃ (±5℃) during and after the electrocauterization of the bladder neck for 10 seconds. The safety endpoint was device-related complications or significant changes in the core body temperature of the pigs. The NVB temperature was below 30℃ within 3 minutes of activation of the rectal balloon. The temperature of the proximal NVB was consistently maintained below 25℃ in all cases. The temperature 1 cm from the bladder neck did not rise above 38°C and dropped to the initial level within 1 minute after electrocauterization. During cooling, the minimum temperature at the apex of the prostate was reduced to 10.1℃. There were no device-related complications or significant changes in core body temperature throughout the experiment. Animal tests suggest the feasibility and safety of this novel rectal cooling system. A first-in-human trial to assess the safety and efficacy of this system during radical prostatectomy is warranted.

Effects of intraoperative hypothermia on stress hormon response in surgical patients

Background/Aim. Surgical stress itself, as well as hypothermia induced by general anesthesia and low ambient temperature, activates stress hormone response with changes in catecholamines and counter-regulatory hormones. The aim of this study was to investigate the acute hormone stress response in patients who underwent major surgical procedures and the efficiency of external and internal warming methods in alleviating these changes. Methods. The study included a total of 60 patients who underwent major open abdominal surgical procedures and were randomly divided into 4 groups: control non-warmed (C), externally warmed using forced-air warming mattress (W), internally warmed using intravenous amino acids (A), and warmed with a combination of external and internal method (A+W). Esophageal temperature was used as a measure of core temperature. Concentrations of epinephrine, norepinephrine, cortisol, prolactin, and testosterone were measured. Blood samples for hormone measurement were obtained at two time points for catecholamines ? 90 min before and 120 min after finishing the surgery, and at additional two-time points for cortisol, prolactin, and testosterone (24 and 48 hrs after surgery). Results. In the W and A+W groups, the temperatures did not significantly differ between time points but constantly decreased in the C and A groups, with a statistically significant difference between the anesthesia induction and the 120th min (35.61 ? 042 vs. 33.86 ? 0.71?C; p &lt; 0.000 and 35.81 ? 0.54 vs. 34.45 ? 0.41?C; p &lt; 0.000, respectively). Catecholamine concentrations in all groups showed a significant increase during surgery, with the highest values recorded in the non-warmed group (777.07 ? 800.08 after vs. 106.13 ? 89.63 pg/mL before surgery for epinephrine and 1,349.67 ? 984.16 vs. 580.53 ? 465.38 for norepinephrine, p &lt; 0.000). Concentrations of cortisol and prolactin also showed a significant increase at the same time point, with a tendency to normalize after 48 hrs. On the contrary, testosterone concentrations showed a decrease after 120 min without normalization throughout the entire period of observation. Except for testosterone, changes in all stress hormones were attenuated in warmed groups compared to controls. Conclusions. Regarding both features of surgical stress investigated in this study (hypothermia and stress hormone response), the combination of endogenous amino acid-induced thermogenesis and external air warming mattress is most effective in its prevention.