Incidence Of Intraoperative Hypothermia Research Articles

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.

Incidence and associated factors of perioperative hypothermia in adult patients at a university-based, tertiary care hospital in Thailand

BackgroundInadvertent perioperative hypothermia is an unintentional drop in core body temperature to less than 36 °C perioperatively and is associated with many negative outcomes such as infection, a prolonged stay in a recovery room, and decreased patient comfort.ObjectiveTo determine the incidence of postoperative hypothermia and to identify the associated factors with postoperative hypothermia in patients undergoing head, neck, breast, general, urology, and vascular surgery. The incidences of pre- and intraoperative hypothermia were examined as the intermediate outcomes.Materials and methodsA retrospective chart review was conducted in adult patients undergoing surgery at a university hospital in a developing country for two months (October to November 2019). Temperatures below 36 °C were defined as hypothermia. Univariate and multivariate analyses were used to identify factors associated with postoperative hypothermia.ResultsA total of 742 patients were analyzed, the incidence of postoperative hypothermia was 11.9% (95% CI 9.7%-14.3%), and preoperative hypothermia was 0.4% (95% CI 0.08%-1.2%). Of the 117 patients with intraoperative core temperature monitoring, the incidence of intraoperative hypothermia was 73.5% (95% CI 58.8–90.8%), and hypothermia occurred most commonly after anesthesia induction. Associated factors of postoperative hypothermia were ASA physical status III-IV (OR = 1.78, 95%CI 1.08–2.93, p = 0.023) and preoperative hypothermia (OR = 17.99, 95%CI = 1.57-206.89, p = 0.020). Patients with postoperative hypothermia had a significantly longer stay in the PACU (100 min vs. 90 min, p = 0.047) and a lower temperature when discharged from PACU (36.2 °C vs. 36.5 °C, p < 0.001) than those without hypothermia.ConclusionThis study confirms that perioperative hypothermia remains a common problem, especially in the intraoperative and postoperative periods. High ASA physical status and preoperative hypothermia were associated factors of postoperative hypothermia. In order to minimize the incidence of perioperative hypothermia and enhance patient outcomes, appropriate temperature management should be emphasized in patients at high risk.RegistrationClinical Trials.gov (NCT04307095) (13/03/2020).

The Effect of Postinduction Blood Glucose on Intraoperative Hypothermia

Background and Objectives: Hypothermia frequently occurs in patients undergoing surgery and is associated with adverse complications. Therefore, this study aimed to investigate the postinduction blood glucose and occurrence of intraoperative hypothermia in patients undergoing laparoscopic surgery. Materials and Methods: This retrospective observational study included 334 patients aged ≥20 years who had undergone elective laparoscopic surgery. The primary outcome of this study was the incidence of intraoperative hypothermia. Stratified analysis revealed differences between patients with and without diabetes. Results: Hypothermia occurred in 200 (59.9%) patients. In multivariate analysis, out-of-range postinduction glucose was independently associated with hypothermia (>150 mg/dL: odds ratio 2.17, 95% confidence interval (1.02, 4.61), p = 0.045; <110 mg/dL: odds ratio 2.02, 95% confidence interval (1.15, 3.55), p = 0.015), whereas preoperative HbA1c >6% was not significantly associated with hypothermia (odds ratio 1.02, 95% confidence interval (0.56, 1.84), p = 0.961). Considering only patients with diabetes, the incidence of hypothermia was lower (p = 0.002), the duration of hypothermia was shorter (p = 0.007), and the minimum temperature was higher (p = 0.006) in those with a postinduction glucose level of 110-150 mg/dL. Conclusions: The postinduction glucose level is independently associated with intraoperative hypothermia. Out-of-range postinduction glucose appeared to have an impact on the development of hypothermia in patients with diabetes, especially those with a postinduction glucose level <110 mg/dL.

Validation of a Prediction Model for Intraoperative Hypothermia in Patients Receiving General Anesthesia.

Objectives There have been no fully validated tools for the rapid identification of surgical patients at risk of intraoperative hypothermia. The objective of this study was to validate the performance of a previously established prediction model in estimating the risk of intraoperative hypothermia in a prospective cohort. Methods In this observational study, consecutive adults scheduled for elective surgery under general anesthesia were enrolled prospectively at a tertiary hospital between September 4, 2020, and December 28, 2020. An intraoperative hypothermia risk score was calculated by a mobile application of the prediction model. A wireless axillary thermometer was used to continuously measure perioperative core temperature as the reference standard. The discrimination and calibration of the model were assessed, using the area under the receiver operating characteristic curve (AUC), Hosmer–Lemeshow goodness-of-fit test, and Brier score. Results Among 227 participants, 99 (43.6%) developed intraoperative hypothermia, and 10 (4.6%) received intraoperative active warming with forced-air warming. The model had an AUC of 0.700 (95% confidence interval [CI], 0.632–0.768) in the overall cohort with adequate calibration (Hosmer–Lemeshow χ2 = 13.8, P=0.087; Brier score = 0.33 [95% CI, 0.29–0.37]). We categorized the risk scores into low-risk, moderate-risk, and high-risk groups, in which the incidence of intraoperative hypothermia was 23.0% (95% CI, 12.4–33.5), 43.4% (95% CI, 33.7–53.2), and 62.7% (95% CI, 51.5–74.3), respectively (P for trend <0.001). Conclusions The intraoperative hypothermia prediction model demonstrated possibly helpful discrimination and adequate calibration in our prospective validation. These findings suggest that the risk screening model could facilitate future perioperative temperature management.

Comparison of Core Body Temperatures in Patients Administered Remimazolam or Propofol during Robotic-Assisted and Laparoscopic Radical Prostatectomy.

Background and Objectives: Different types of anesthetics affect thermoregulatory mechanisms, such as the redistribution of body temperature, loss of skin heat, or inhibition of thermoregulatory vasoconstriction. Therefore, we compared remimazolam with propofol in terms of core body temperature in patients undergoing robotic-assisted and laparoscopic radical prostatectomy. Materials and methods: Ninety patients were randomly assigned to either the propofol–remifentanil (PR) group or the remimazolam–remifentanil (RR) group. The PR group (n = 45) received effect-site concentrations of 6.0 μg/mL of propofol and 4 ng/mL of remifentanil, followed by 0.9 mg/kg of 1% rocuronium and maintenance with effect-site concentrations of 2–4 μg/mL of propofol and 3 ng/mL of remifentanil. The RR group (n = 45) received remimazolam 6 mg/kg/h by continuous intravenous infusion and the effect-site concentration of 4 ng/mL of remifentanil, followed by 0.9 mg/kg of 1% rocuronium, remimazolam 1–3 mg/kg/h, and remifentanil 3 ng/mL. The primary outcome was core body temperature, and secondary outcomes included vasoconstriction threshold (°C) and time to onset of vasoconstriction (min). Results: The core body temperature in the RR group was significantly higher at 60, 80, 100, 120, 140, 160, and 180 min after induction than in the PR group (p < 0.01). The vasoconstriction threshold was significantly higher in the RR group (35.2 ± 0.4) than in the PR group (34.8 ± 0.3) (p < 0.01). The time to onset of vasoconstriction was significantly less in the RR group (150.5 ± 10.2) than in the PR group (158.5 ± 8.4) (p < 0.01). However, the incidence of intraoperative hypothermia was not significant between two groups. Conclusions: Remimazolam appears to reduce vasoconstriction threshold less than and had a faster onset of vasoconstriction, resulting in superior thermoregulatory control.

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.

Analysis of the Incidence of Intraoperative Hypothermia and its Influencing Factors in Gynecological Patients Undergoing Laparoscopic Surgery

Analysis of the Incidence of Intraoperative Hypothermia and its Influencing Factors in Gynecological Patients Undergoing Laparoscopic Surgery

A descriptive study of the relationship between preoperative body temperature and intraoperative core temperature change in adults under general anaesthesia

Background: Despite numerous guidelines on perioperative temperature management, perioperative hypothermia remains common. Prewarming to prevent redistribution hypothermia is supported by evidence, but not widely practised. We investigate the measurement of preoperative mean body temperature as a potential tool for individualising the practice of prewarming. Methods: We hypothesised that patients who experience intraoperative hypothermia have a lower preoperative mean body temperature. A longitudinal study was conducted in adult patients presenting for ophthalmological surgery under general anaesthesia, to describe the relationship between the incidence of hypothermia within the first hour of anaesthesia and preoperative mean body temperature. Results: Sixty-five patients were enrolled. Twelve participants (18%) presented to the operating theatre hypothermic (core temperature < 36.0 °C). A further 28 (43%) became hypothermic during the procedure. All hypothermia events occurred within 60 minutes after induction of anaesthesia, and half of the events occurred within 19 minutes. The difference in preoperative mean body temperature between those with and without intraoperative hypothermia was only -0.2 °C (95% CI -0.4, 0.1). This is neither clinically relevant nor statistically noteworthy. In Cox proportional hazards analysis, BMI and ASA status compounded the observed association between preoperative mean body temperature and the incidence of intraoperative hypothermia. A higher BMI and ASA are associated with a lower incidence of hypothermia. Conclusion: We conclude that intraoperative hypothermia is common and occurs early after induction of anaesthesia. We observed no useful difference in preoperative mean body temperature to help distinguish between patients who become hypothermic and those who do not. Without a useful risk prediction tool, a generic approach to prewarming remains appropriate. Preoperative screening for pre-existing hypothermia should be practised, even in cases considered as low risk.

PP352 Systematic Review Of Clinical Effects Of Different Thermal Insulation Measures In Patients Undergoing Major Surgery

IntroductionHypothermia (core temperature &lt;36°C) during major surgeries could result in a number of adverse events such as surgical site infection, bleeding, and prolonged hospital stay. The incidence of intraoperative hypothermia was 44.3 percent in China in 2015, with only 10.7 percent of patients receiving effective hypothermia prevention measures during major surgeries. By systematically examining the adverse risks for patients using different warming measures (active and passive), our study discussed the potential of bringing the most effective one(s) into clinical guidelines.MethodsArticles, ongoing trials and grey literatures were retrieved from PubMed, The Cochrane Library and Clinical Trials till February 2019. Bair HuggerTM (BH) was determined to be the reference group and all randomized controlled trials including BH were included. In the control group, we kept all possible warming measures. Adverse effect indicators were decided using scoping reviews and then applied in literature screening. Type (open/endoscopic) and length of surgery were included in sub-group analysis.ResultsA total of forty-two studies were included, with twenty-seven of them passive insulation measures and fifteen active measures. Compared with passive measures, BH had significant advantages, such as in surgical site infection (risk ratio [RR] = 0.13, 95% confidence interval [CI]: 0.05, 0.80), chills (RR = 0.37, 95% CI: 0.25, 0.54) and hospitalization stay (mean difference [MD]=−1.27d, 95% CI: -2.05, -0.48). Compared with active insulation measures, BH had no significant advantages. Patients with open or longer surgeries (≥2 hours) experienced higher risks.ConclusionsGenerally, an active warming system is more effective in lowering risks (e.g., hypothermia, surgical site infection, chills, length of stay) than passive ones, especially for patients going through non-endoscopic or longer surgeries. Among the active warming systems, BH does the same job as other active insulation measures. Given that the practice of peri-operative hypothermia prevention using active warming systems is not popular in China, the use of BH and other active insulation measures during major surgeries are recommended to improve the safety and potentially reduce the cost of treating those clinical adverse events.

Thermal suit connected to a forced-air warming unit for preventing intraoperative hypothermia: A randomised controlled trial.

Inadvertent intraoperative hypothermia is a common occurrence in surgical patients. A thermal suit is an option for passive insulation. However, active warming is known to be more effective. Therefore, we hypothesised that a forced-air warming (FAW) unit connected to the thermal suit is superior to a commercial FAW blanket and a warming mattress in breast cancer surgery. Forty patients were randomised to this prospective, clinical trial to wear either the thermal suit or conventional hospital clothes under general anaesthesia. The Thermal suit group had a FAW unit set to 38°C and connected to the legs of the suit. The Hospital clothes group had a lower body blanket set to 38°C and a warming mattress set to 37°C. Core temperature was measured with zero-heat-flux sensor. The primary outcome was core temperature on admission to the recovery room. There was no difference in mean core temperatures at anaesthetic induction (P=.4) or on admission to the recovery room (P=.07). One patient in the Thermal suit group (5%) vs six patients in the Hospital clothes group (32%) suffered from intraoperative hypothermia (P=.04, 95% CI 1.9%-49%). Mean skin temperatures (MSTs) were higher in the Thermal suit group during anaesthesia. No burns or skin irritations were reported. Two patients in the Thermal suit group sweated. A thermal suit connected to a FAW unit was not superior to a commercial FAW blanket, although the incidence of intraoperative hypothermia was lower in patients treated with a thermal suit.

The low fresh gas flow anesthesia and hypothermia in neonates undergoing digestive surgeries: a retrospective before-after study

BackgroundBased on the previous investigation in our institution, the incidence of intraoperative hypothermia in neonates was high. Since September 1st, 2019, the recommendation had been launched to utilize ≤1 L/min fresh gas flow during the neonates’ surgical procedure. We therefore intended to evaluate the association between low fresh gas flow anesthesia and the occurrence of hypothermia in neonates undergoing digestive surgeries.MethodsA retrospective chart review, before-after study was conducted for neonates who underwent digestive surgeries. The primary outcomes were the incidence of hypothermia. The secondary outcomes included hospital mortality, the value of lowest temperature, blood loss, mean body temperature during the surgery, the length of hypothermia during the surgery and postoperative hospital length-of- stay (PLOS).Results249 neonates fulfilled the eligibility criteria. The overall incidence of intraoperative hypothermia was 81.9%. The low fresh gas flow anesthesia significantly reduced the odds of hypothermia [routine group: 149 (87.6%) versus low flow group: 55 (69.6%); p < 0.01]. Moreover, the low fresh gas flow anesthesia could reduce the length of hypothermia [routine group: 104 mins (50, 156) versus low flow group: 30 mins (0,100); p < 0.01], as well as elevate the value of lowest temperature for neonates [routine group: 35.1 °C (34.5, 35.7) versus low flow group: 35.7 °C (35.3, 36); p < 0.01]. After adjustment for confounding, low fresh gas flow anesthesia and the length of surgical time were independently associated with intraoperative hypothermia.ConclusionsLow fresh gas flow anesthesia is an effective way to alleviate hypothermia in neonates undergoing open digestive surgery.

Effect of temperature maintenance by forced-air warming blankets of different temperatures on changes in inflammatory factors in children undergoing congenital hip dislocation surgery.

BackgroundHypothermia is associated with many adverse clinical outcomes in pediatric patients, and thus, it is important to find an effective and safe method for preventing peri-operative hypothermia and its associated adverse outcomes in pediatric patients. This study aimed to investigate the effect of forced-air warming blankets with different temperatures on changes in the transforming growth factor-β (TGF-β), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-10 levels in children undergoing surgical treatment for developmental displacement of the hip (DDH).MethodsThe study included 123 children undergoing surgery for DDH under general anesthesia. The patients were randomly assigned to three groups, using a random number table: the 32, 38, and 43°C groups according to the temperature setting of the forced-air warming blankets. For each patient, body temperature was recorded immediately after anesthesia induction and intubation (T0), at initial incision (T1), at 1 h after incision (T2), at 2 h after incision (T3), at the end of surgery (T4), immediately upon return to the ward after surgery (T5), and then at 12 h (T6), 24 h (T7), 36 h (T8), and 48 h (T9) after the surgery. The serum levels of TGF-β, TNF-α, IL-1β, and IL-10 were measured at T0 and T4 for all groups.ResultsThe number of patients with fever in the 38°C group was significantly less than those in the 32 and 43°C groups (χ2 = 6.630, P = 0.036). At T0, the body temperatures in the 38 and 43°C groups were significantly higher than that in the 32°C group (F = 17.992, P < 0.001). At T2, the body temperature was significantly higher in the 43°C group than those in the 32 and 38°C groups (F = 12.776, P < 0.001). Moreover, at T4, the serum levels of TGF-β (F = 3286.548, P < 0.001) and IL-10 (F = 4628.983, P < 0.001) were significantly increased in the 38°C group, and the serum levels of TNF-α (F = 911.415, P < 0.001) and IL-1β (F = 322.191, P < 0.001) were significantly decreased in the 38°C group, compared with the levels in the 32 and 43°C groups.ConclusionForce-air warming blankets set at 38°C maintained stable body temperature with less adverse outcome and effectively inhibited the inflammatory response in pediatric patients undergoing surgery for DDH.Clinical trial registrationChiCTR1800014820; http://www.chictr.org.cn/showproj.aspx?proj=25240.

The Impact of Intraoperative Hypothermia on Blood Loss and Allogenic Blood Transfusion in Total Knee and Hip Arthroplasty: A Retrospective Study.

Background Total joint arthroplasty (TJA) usually leads to substantial blood loss, which may cause allogenic blood transfusion. Hypothermia occurring during operation has been reported to increase blood loss and transfusion rates in nonorthopedic cohorts. However, the relationship between intraoperative hypothermia and blood loss remains controversial in patients undergoing orthopedic surgeries. The aims of this study were to investigate the incidence of hypothermia and identify the impact of intraoperative body temperature and hypothermia on blood loss and transfusion rates in total knee and hip arthroplasty (TKA and THA, respectively). Methods This retrospective study enrolled 616 consecutive patients, who underwent primary unilateral TKA or THA at our institution during the period from April 2012 to July 2014. The occurrence of a temperature below 36°C during the operation was documented to identify the incidence of hypothermia. Univariate analysis was performed to find the risk factors for hypothermia. Multiple regression analysis and multivariate logistic regression analysis were employed to explore the association of intraoperative temperature and hypothermia with intraoperative blood loss and perioperative blood transfusion. Results The incidence of intraoperative hypothermia was 13.5%, 14.0%, and 13.1% in TJA, TKA, and THA, respectively. Intraoperative temperature (P = 0.045, P = 0.006) and hypothermia (P = 0.042, P < 0.001) were associated with intraoperative blood loss and perioperative transfusion in TKA. Intraoperative temperature (P = 0.002) was negatively related to the amount of blood loss, and hypothermia (P = 0.031) was the independent risk factor for transfusion in THA. Conclusion Intraoperative hypothermia is associated with increased blood loss and transfusion rates in TJA. Efforts should be made to maintain normothermia during operation in these patients.

Comparison of efficacy of active forced-air warming for preventing perioperative hypothermia between the elderly and young patients

Objective To observe whether the active forced-air warming has the same efficacy on the prevention of perioperative hypothermia in the elderly as compared with young patients. Methods This was a prospective, randomized, controlled clinical trial.Forty patients scheduled for abdominal surgery under general anesthesia were allocated to two groups: the elderly group and the young group(n=20, each). All patients received active forced-air warming at 20-30 min before induction of anaesthesia till leaving the operation room.Blood products and peritoneal lavage fluids were warmed to 37℃, and other intravenous fluids were at room-temperature.The core temperatures were recorded after entering the operation room(baseline), before induction of anaesthesia, at 15 min intervals after induction of anaesthesia, at the end of surgery and before leaving the operation room.The postoperative shivering and adverse reactions were also recorded. Results The core temperature was lower in elderly patients than in young patients at baseline and at each time points after 30 min of induction of anaesthesia(P<0.05). In elderly patients, the core temperature was significantly lower before leaving operation room than at the baseline(t=2.353, P=0.03), but in young patients, no significant difference was found in the core temperature between at the baseline and before leaving operation room(t=0.233, P=0.818). The incidence of intra-operative hypothermia was higher in elderly patients than in young patients(40.0% or 8/20 vs.5.0% or 1/20, c2=7.025, P=0.008). Conclusions During abdominal surgery under general anesthesia, active forced-air warming cannot effectively prevent perioperative hypothermia in elderly patients as compared with young patients. Key words: Anesthesia, general; Body temperature regulation

Prewarming effect of transcutaneous acupoint electrical stimulation preconditioning in patients undergoing elective video-assisted thoracoscopic lobectomy

To observe the prewarming effect of transcutaneous acupoint electrical stimulation (TAES) preconditioning of Dazhui (GV14) and Mingmen (GV4) in patients undergoing elective video-assisted thoracoscopic lobectomy, so as to determine whether TAES can improve intraoperative hypothermia. A total of 80 patients undergoing elective video-assisted thoracoscopic lobectomy were randomly divided into TAES group (40 cases) and control group (40 cases). Before surgery, all the patients were transferred to the fixed area of an anesthetic preparation room by using a surgery cart carrying the same temperature sheets and quilts before surgery. TAES (2 Hz/100 Hz, 20-30 mA) was applied to Dazhui (GV14) and Mingmen (GV4) for 30 min for patients of the TAES group and the same sheet electrodes of EA stimulator were only attached to GV14 and GV 4 without electrical current transmission for patients in the control group. Then, these patients in the two groups were transferred to the operation room and treated by total intravenous anesthesia, and their anesthetic depth was monitored with bispectral index (BIS, between 45-60) and end-tidal carbon dioxide tension (PETCO2, between 30-45 mmHg). The auricular tympanic temperature was monitored, and when the temperature was below 35.5 ℃, forced-air blanket was used to warm the patient as the remedial measure. The same temperature of operation room, surgical drape, infusion solution and pleural lavage fluid were controlled. The patients' body temperature in the preparation room and operation room during surgery, incidence of hypothemia, blood pressure (BP), heart rate (HR), duration of anesthesia, duration of operation, blood loss volume, urine output, total infusion volume, recovery (awaking) time, and chills during recovery were recorded. The body temperature of patients in the TAES group was significantly higher than that in the control group at the time of entering the operation room (P<0.05). The incidence of chills during recovery was obviously lower in the TAES group (3/40,7.5%) than in the control group (7/40, 17.5%, P<0.05), and the recovery time was significantly shorter in the TAES group than in the control group (P<0.05). There were no significant differences between the two groups in the incidence of intraoperative hypothermia, the duration of anesthesia and operation, blood loss volume, urine output, total infusion volume, BP and HR (P>0.05). TAES preconditioning of GV14 and GV4 can produce prewarming effect before anesthesia, shorten the awaking time and reduce the incidence of chills in the recovery period in patients undergoing elective video-assisted thoracoscopic lobectomy.

Perioperative Risk Factors for Intraoperative Hypothermia in Adult Patients Undergoing Elective Surgery at a National Referral Hospital in Bhutan: A Prospective Observational Study

Objective: Intraoperative hypothermia is commonly encountered in anesthetic practice. It is related to several risk factors and can lead to various adverse events. It is important to detect it early and prevent the complications related to it. This study was done to identify incidence and perioperative risk factors of intraoperative hypothermia at a national referral hospital in Bhutan.Material and Methods: A prospective observational study was conducted in adult patients who underwent elective surgery lasting more than 30 minutes. Patient characteristics, incidence of hypothermia, and any interventions for treatment of hypothermia during the operation were recorded. Intraoperative hypothermia was defined as a core body temperature less than 36 °C measured with an esophageal probe.Results: Data were obtained from 91 patients with a mean (±standard deviation; S.D.) age of 42.3 (17.2) and American Society of Anesthesiologists (ASA) scores of 1 and 2 in 62.6% and 37.4% of the patients, respectively The patients underwent elective surgery with a mean (S.D.) duration of 73.24 (48.1) minutes and a mean (S.D.) duration of anaesthesia of 80.9 (49.2) minutes. The incidence of intraoperative hypothermia was 61.5% (56/91). Preoperative heart rate more than 80 beats per minute [hazard ratio (HR) 0.45, 95% confidence interval (CI), 0.26-0.77] was a protective factor and duration of anesthesia more than 60 minutes (HR 1.82, 95% CI, 0.98–3.38) was a risk factor for intraoperative hypothermia.Conclusion: Patients with a preoperative heart rate less than 80 beats per minute and undergoing duration of anesthesia more than 60 minutes should be assessed from the preoperative period and continuously monitored throughout the intraoperative period.

Preoperative factors affecting the intraoperative core body temperature in elective hysterectomy under general anesthesia

Background: Hypothermia is common in patients undergoing anesthesia surgery and it may increase the potential risk of post-operative complications. The purpose of this study was to investigate the intraoperative factors that affect the core temperature of women after hysterectomy. Materials and Methods: One hundred and four female patients aged 18 and older, who were treated with elective open hysterectomy, were studied. The authors evaluated the incidence of hypothermia with respect to demographics, clinical, and anesthesia characteristics in two patients groups (hypothermic vs. normothermic). Results: The incidence of intraoperative hypothermia was 53.8. Advanced age (OR=6.449; 95% CI 3.603-14.397, p &lt; 0.001), higher BMI (OR=5.879; 95% CI 5.122-7.325), higher intraoperative core body temperature (OR=0.483; 95% CI 0.432-0.578), large surgeries (OR=4.149; 95% CI 3.549-5.881, p &lt; 0.001), and the number of opioids (OR=0.199; 95% CI 0.084-0.428) were found to be the most important predictors for hypothermia intraoperatively. There was significant statistical difference between the two groups with respect to American Society of Anaesthesiologists’ (ASA) score, induction to anesthesia with propofol and sevoflurane, and the administration of muscle relaxants perioperatively. Conclusions: The application of an appropriate, simple, and low-cost heating method, either by administrating warmed intravenous fluids or using an air-heating flow device, can help to prevent surgical patients’ hypothermia and its possible dangerous complications.

Factors associated with intraoperative hypothermia in elderly patients and management strategies

Objective To investigate the incidence of intraoperative hypothermia in elderly patients, and to analyze and discuss related influencing factors and targeted management strategies. Methods From February 2017 to February 2019, 220 elderly patients admitted into our hospital for surgery were selected.According to whether or not they had intraoperative hypothermia, patients were divided into the hypothermia group and the non-hypothermia group.General information and surgical data were compared between the two groups.Measures for the prevention of intraoperative hypothermia were discussed. Results Of the 220 patients, 103 had intraoperative hypothermia, and the incidence rate was 46.8%.The proportion of patients aged ≥70 years or with BMI <24 kg/m2 was higher in the hypothermia group than in the non-hypothermia group(all P<0.05). The proportion of patients with the anesthesia time ≥60 min or total intraoperative fluid intake ≥2000 ml was higher in the hypothermia group than in the non-hypothermia group(all P<0.05). BMI <24 kg/m2 and total intraoperative fluid intake ≥2000 ml were the key risk factors for intraoperative hypothermia in elderly patients(all P<0.05). Conclusions Intraoperative hypothermia is a common complication for elderly patients undergoing surgery.Intraoperative fluid intake and body mass are the key risk factors for intraoperative hypothermia.Targeted treatment measures based on the above related factors should be considered for elderly patients receiving surgery. Key words: Body temperature changes; Related factors

Effect of forced-air warming by an underbody blanket on end-of-surgery hypothermia: a propensity score-matched analysis of 5063 patients

BackgroundUnderbody blankets have recently been launched and are used by anesthesiologists for surgical patients. However, the forced-air warming effect of underbody blankets is still controversial. The aim of this study was to determine the effect of forced-air warming by an underbody blanket on body temperature in anesthetized patients.MethodsWe retrospectively analyzed 5063 surgical patients. We used propensity score matching to reduce the bias caused by a lack of randomization. After propensity score matching, the change in body temperature from before to after surgery was compared between patients who used underbody blankets (Under group) and those who used other types of warming blankets (Control group). The incidence of hypothermia (i.e., body temperature < 36.0 °C at the end of surgery) was compared between the two groups. A p value < 0.05 was considered to indicate statistical significance.ResultsWe obtained 489 propensity score-matched pairs of patients from the two groups, of whom 33 and 63 had hypothermia in the Under and Control groups, respectively (odds ratio: 0.49, 95% confidence interval: 0.31–0.76, p = 0.0013).ConclusionsThe present study suggests that the underbody blanket may help reduce the incidence of intraoperative hypothermia and may be more efficient in warming anesthetized patients compared with other types of warming blankets.Trial registrationUMIN Clinical Trials Registry (Identifier: UMIN000022909; retrospectively registered on June 27, 2016).

Significant factors influencing inadvertent hypothermia in pediatric anesthesia.

Thermal imbalances are very common during surgery. Hypothermia exposes the patient to post-operative shivering, cardiac dysfunction, coagulopathy, bleeding, wound infection, delayed anesthesia recovery, prolonged hospital stay and increased hospitalization cost. There are many factors contributing to intraoperative hypothermia. This is a prospective cohort study conducted through observation and measurement of pediatric surgical patients' temperature. Convenience sampling methods were used in this study. Initial skin temperature and core temperature at 10min, 30min,1h, 2h, 3h, 4h, 5h, 6h and at the end of surgery were recorded. Body temperature was monitored from time of transfer to the operating table until recovery and discharge to the respective pediatric ward. The overall incidence of intraoperative hypothermia was still very high at about 46.6% even though active and passive temperature management were carried out during surgery. Patient's age, body weight, duration of surgery, type of surgery, intraoperative blood loss, type of anesthesia and operating room temperature were factors that contributed to intraoperative hypothermia. Hypothermia is common in surgery, especially in major and long duration surgery. Intraoperative hypothermia can be life threatening if it is not handled carefully. Various methods are used before, during and after surgery to maintain a patient's body temperature within the normothermia range. The use of an active warming device like the Bair Hugger® air-forced warming system seems to be a good method for reducing the risk of intraoperative hypothermia and effectively maintaining body temperature for all major and minor surgeries.