Intraoperative Warming Research Articles

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.

The effect of systemic intraoperative warming on cardiac function of patients after off-pump coronary bypass grafting

The effect of systemic intraoperative warming on cardiac function of patients after off-pump coronary bypass grafting

A STUDY OF WARMING DEVICES AND PERIOPERATIVE FACTORS POTENTIALLY CONTRIBUTING TO SURGICAL FIELD CONTAMINATION IN SMALL ANIMAL PATIENTS

Bacterial contamination on surgical drapes may increase the risk of surgical site infection (SSI). This preliminary investigation analyzed the relationship between forced-air warming devices and bacterial contamination on surgical drapes in small animal soft tissue surgery settings. The subjects of this study were canine and feline patients enrolled in clean surgical procedures at the National Taiwan University Veterinary Hospital. Bacterial colonies on surgical drapes were sampled on agar plates immediately prior to and 1[Formula: see text]h after skin incision. Cases with bacteria growth on the post-incision sampled agar were considered with surgical field contamination (SFC). Intraoperative warming methods (forced-air warming systems or circulating water blankets) and other factors that potentially contribute to SFC (drape material, patient features, surgical procedure types, surgeons, and number of operating room personnel) were recorded. The study comprised 57 operations, 28 cases belonged to the circulating water blanket group and 29 belonged to the forced-air warming system group. No differences in contamination rate were detected among intraoperative warming methods, drape materials, patient characteristics, surgical procedure types, or number of operating room personnel. However, a significant difference in contamination rate was detected among surgeons.

Enhanced PeriOperative Care and Health protection programme for the prevention of surgical site infections after elective abdominal surgery (EPO2CH): statistical analysis plan of a randomised controlled multicentre superiority trial

BackgroundSurgical site infections (SSI) are frequent complications after elective abdominal surgery. We designed the Enhanced PeriOperative Care and Health Protection programme (EPO2CH) care bundle, comprising of intraoperative high fractional inspired oxygen; intraoperative goal-directed fluid therapy; active preoperative, intraoperative and postoperative warming; glucose control and treatment of hyperglycaemia (> 10 mmol L− 1) in diabetics as well as non-diabetics; and wound irrigation before closure using an aqueous antiseptic. We hypothesise that EPO2CH added to standard care reduces the incidence of SSI compared to standard care alone for elective abdominal surgery.MethodsThis trial is designed as an open label, pragmatic randomised controlled parallel-group multicentre superiority trial. The primary endpoint is the incidence of SSI, defined by the Centers for Disease Control and prevention, within 30 days after surgery. The incidence of SSI is assessed using the Dutch national complication register and medical chart review. Secondary endpoints include the SSI incidence within 90 days, incidence of anastomotic leakage at 30 and 90 days, the incidence of incisional hernia within 1 year, mortality within 1 year and 5 years, quality of life, health and disability, and cost-effectiveness. Primarily, an intention-to-treat analysis will be performed to estimate the relative risk using a log binomial model. If not feasible, a logistic regression will be used to estimate the odds ratio. A per-protocol analysis will also be performed. Furthermore, the attributive effect of the distinct interventions will be explored.DiscussionThe results of the EPO2CH trial will determine if the EPO2CH bundle is effective to prevent SSI incidence for patients undergoing elective abdominal surgery. Details of the statistical analysis are described in this Statistical Analysis Plan (SAP).Trial registrationRegistration number: Dutch Trial Register Trial NL5572. Registered on March 3, 2016.SAP version: V1.0, January 8, 2020. This SAP has been written based on study protocol V10.

Efficacy of active forced air warming during induction of anesthesia to prevent inadvertent perioperative hypothermia in intraoperative warming patients: Comparison with passive warming, a randomized controlled trial.

Background:This study aimed to evaluate the efficacy of peri-induction forced air warming to prevent inadvertent perioperative hypothermia, defined as a reduction in body temperature to <36.0°C during the perioperative period, in intraoperatively warmed patients receiving major surgery lasting >120 minutes.Methods:In total, 130 patients scheduled for elective surgery under general anesthesia lasting >120 minutes were divided into 2 groups: peri-induction warming (n = 65) and control (n = 65). Patients in the peri-induction warming group were warmed during the anesthetic induction period using a forced-air warmer set at 47°C, whereas patients in the control group were covered passively with a cotton blanket. All patients were warmed with a forced-air warmer during surgery. Body temperature was measured using a tympanic membrane thermometer in the pre- and postoperative periods and using a nasopharyngeal temperature probe during surgery. Patients were evaluated for shivering scale score, thermal comfort scale score, and satisfaction score in the post-anesthesia care unit.Results:The incidence rates of intraoperative and postoperative hypothermia were lower in the peri-induction warming group than in the control group (19.0% vs 57.1%, P < .001; 3.3% vs 16.9%, P = .013, respectively). Body temperature was higher in the peri-induction warming group (P < .001). However, intraoperative blood loss, as well as postoperative thermal comfort scale score, shivering scale score, and patient satisfaction score, were similar between groups. Post-anesthesia care unit duration was also similar between groups.Conclusions:Peri-induction active forced air warming is an effective, simple, and convenient method to prevent inadvertent perioperative hypothermia in intraoperatively warmed patients undergoing major surgery lasting >120 minutes.

Comparison of Combined Forced-Air Warming and Circulating-Water-Mattress and Forced-Air Warming Alone in Patients Undergoing Open Abdominal Surgery in Lithotomy Position: a Randomized Controlled Trial

The objective of this study was to evaluate the efficacy of warming devices in patients undergoing open abdominal surgery in lithotomy position. This randomized, controlled trial was designed to compare body temperatures of patients undergoing open abdominal surgery in lithotomy position between February and May 2019. After prewarming for 30 min with forced-air using a full-body blanket, patients were randomized to receive intraoperative warming either with forced-air using a blanket covering the upper torso and upper extremities in combination with circulating-water-mattress warming the back (Group I) or with only forced-air using blanket covering the upper torso and upper extremities (Group II). Primary outcome measure was the intraoperative change in core-body temperature using oesophageal temperature probe. A total of 28 patients were randomized. The mean core-body temperatures (Group I: 36.1 SD0.41 vs Group II: 35.9 SD0.53 °C; p=0.139) and intraoperative changes (Group I: 0.41% vs Group II: − 0.001%; p=0.306) were similar. The core-body temperature at the end of the operation correlated with the operating room temperature in Group II (r=0.862, p<0.001), but not in Group I (r=0.323, p=0.259). The combination of forced-air warming and circulating-water-mattress for open abdominal surgery in the lithotomy position may be more beneficial than forced-air warming alone, due to maintenance of the intraoperative mean core-body temperature ≥36°C, despite variations in operating room temperature. Trial Registry Number: ClinicalTrials.gov Identifier: NCT03824262 (Date of registry: 29 January 2019)

Assessment of intraoperative temperature management at the University Teaching Hospital of Kigali: A quality improvement project

Background: Due to the inhibition of thermoregulation by anesthetics, hypothermia occurs in 50% of patients undergoing general and neuraxial anesthesia without active warming. High-quality research has shown the negative effects of intraoperative hypothermia including increased rates of surgical site infections, increased hospital length of stay, increased cardiac morbidity and increased rate of transfusion. The University Teaching Hospital of Kigali commonly known as CHUK is the largest public referral hospital in Rwanda. The International Standards for Safe Anesthesia were not being met regarding intraoperative temperature management at CHUK. However, due to high ambient temperature in the operating room, it was unknown if this was a significant problem and worth investment, in a health system, with limited resources. Methods: After institutional review board approval, a two-stage descriptive cross-sectional quality improvement project was performed. The first stage was to assess current management of intra-operative temperature, determine if there was a significant rate of hypothermia and establish risk factors for developing intra-operative hypothermia in this clinical setting. The second stage was to determine if locally available warming techniques, an underbody warming blanket, significantly reduced the incidence of intra-operative hypothermia. Results: The primary result of the study was a 58% incidence of hypothermia with current standard practice. This was reduced to 6% with the use of an underbody water blanket. Temperature was measure intraoperatively in only 6% of cases and never documented. Adult patients and patients undergoing neuraxial anesthesia were more likely to experience hypothermia. Conclusions: Intraoperative hypothermia is common at CHUK despite high ambient operating room temperature. Monitoring and documentation of temperature is not occurring on a regular basis. The use of underbody water body, though not the gold standard for intraoperative warming, was effective in this study and a realistic solution in an environment with limited resources.

Forced-Air Convection Versus Underbody Conduction Warming Strategies to Maintain Perioperative Normothermia in Patients Undergoing Total Joint Arthroplasty

BackgroundForced-air warming is an established strategy for maintaining perioperative normothermia. However, this warming strategy can potentially contaminate the surgical field by circulating nonsterile air. This study aimed to determine whether changing practice away from this method resulted in non-inferior rates of perioperative hypothermia.MethodsWe performed a chart review of primary total hip and knee arthroplasty patients from 2014 to 2017, when the strategy of intraoperative forced-air warming (FAW) was changed to preoperative FAW along with intraoperative underbody conduction warming (CW) with an underbody warming mattress. Data included patient temperatures throughout all phases of care, blood loss and transfusion requirements, length of postanesthesia care unit (PACU) and hospital stays, and 30-day infection and mortality.ResultsA total of 769 charts were reviewed; 349 patients underwent surgery before the practice change and 420 after. Mean (SD; 95% CI) body temperatures at the time of incision were lower for group 1 than for group 2 (34.55 vs 35.52 °C [0.97 °C; 95% CI, 0.72-1.23 °C]). The average nadir of intraoperative body temperature was lower for group 1 than for group 2 (difference of means, 0.44 °C; 95% CI, 0.18-0.71 °C). Group 2 had a higher percentage of patients who presented hypothermic (temperature <36.0 °C) on arrival in the PACU (12.9% vs 7.7%).ConclusionPreoperative convective warming combined with intraoperative underbody conductive warming maintains normothermia during primary total joint arthroplasty and is non-inferior to forced-air intraoperative warming alone.

Effect of Perioperative Active Body Surface Warming Systems on Analgesic and Clinical Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Inadvertent perioperative hypothermia is a common complication of surgery, and active body surface warming (ABSW) systems are used to prevent adverse clinical outcomes. Prior data on certain outcomes are equivocal (ie, blood loss) or limited (ie, pain and opioid consumption). The objective of this study was to provide an updated review on the effect of ABSW on clinical outcomes and temperature maintenance. We conducted a systematic review of randomized controlled trials evaluating ABSW systems compared to nonactive warming controls in noncardiac surgeries. Outcomes studied included postoperative pain scores and opioid consumption (primary outcomes) and other perioperative clinical variables such as temperature changes, blood loss, and wound infection (secondary outcomes). We searched Ovid MEDLINE daily, Ovid MEDLINE, EMBASE, CINHAL, Cochrane CENTRAL, and Web of Science from inception to June 2019. Quality of evidence (QoE) was rated according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Subgroup analysis sought to determine the effect of preoperative + intraoperative warming versus intraoperative warming alone. Metaregression evaluated the effect of year of publication, use of neuromuscular blockers, anesthesia, and surgery type on outcomes. Fifty-four articles (3976 patients) were included. Pooled results demonstrated that ABSW maintained normothermia compared to controls, during surgery (30 minutes postinduction [mean difference {MD}: 0.3°C, 95% confidence interval {CI}, 0.2-0.4, moderate QoE]), end of surgery (MD: 1.1°C, 95% CI, 0.9-1.3, high QoE), and up to 4 hours postoperatively (MD: 0.3°C, 95% CI, 0.2-0.5, high QoE). ABSW was not associated with difference in pain scores (<24 hours postoperatively, moderate to low QoE) or perioperative opioid consumption (very low QoE). ABSW increased patient satisfaction (MD: 2.2 points, 95% CI, 0.9-3.6, moderate QoE), reduced blood transfusions (odds ratio [OR] = 0.6, 95% CI, 0.4-1.0, moderate QoE), shivering (OR = 0.2, 95% CI, 0.1-0.4, high QoE), and wound infections (OR = 0.3, 95% CI, 0.2-0.7, high QoE). No significant differences were found for fluid administration (low QoE), blood loss (very low QoE), major adverse cardiovascular events (very low QoE), or mortality (very low QoE). Subgroup analysis and metaregression suggested increased temperature benefit with pre + intraoperative warming, use of neuromuscular blockers, and recent publication year. ABSW seemed to confer less temperature benefit in cesarean deliveries and neurosurgical/spinal cases compared to abdominal surgeries. ABSW is effective in maintaining physiological normothermia, decreasing wound infections, shivering, blood transfusions, and increasing patient satisfaction but does not appear to affect postoperative pain and opioid use.

Effects of 10-min prewarming on core body temperature during gynecologic laparoscopic surgery under general anesthesia: a randomized controlled trial.

BackgroundPrevious research has shown a beneficial effect of prewarming for preventing inadvertent perioperative hypothermia. However, there are few studies of the effects of a short prewarming period, especially in gynecologic laparoscopic surgery.MethodsFifty-four patients were randomly assigned to 2 groups. Patients in the non-prewarming group were only warmed intraoperatively with a forced air warming device, while those in the prewarming group were warmed for 10 min before anesthetic induction and during the surgery. The primary outcome was incidence of intraoperative hypothermia.ResultsIntraoperative hypothermia was observed in 73.1% of the patients in the non-prewarming group and 24% of the patients in the prewarming group (P < 0.001). There were significant differences in core temperature changes between the groups (P < 0.001). Postoperative shivering occurred in 8 of the 26 (30.8%) patients in the non-prewarming group and in 1 of the 25 (4.0%) patients in the prewarming group (P = 0.024).ConclusionsForced air warming for 10 min before induction on the operating table combined with intraoperative warming was an effective method to prevent hypothermia in patients undergoing gynecologic laparoscopic surgery.

Effects of 10-min of pre-warming on inadvertent perioperative hypothermia in intraoperative warming patients: a randomized controlled trial.

BackgroundThis study aimed to evaluate the efficacy of 10-min pre-warming in preventing inadvertent perioperative hypothermia, which is defined as a reduction in body temperature to less than 36.0℃ during the perioperative period in intraoperative warming patients.MethodsIn this prospective randomized study, 60 patients scheduled for elective surgery under general anesthesia lasting less than 120 min were divided into two groups: the 10-min pre-warming group (n = 30) and the control group (n = 30). Patients in the 10-min pre-warming group were pre-warmed for 10 min in the pre-anesthetic area using a forced-air warmer set at 47ºC. Intraoperatively, we warmed all patients with a forced-air warmer. Body temperature was measured using a tympanic membrane thermometer pre- or postoperatively and a nasopharyngeal temperature probe intraoperatively. Patients were evaluated on the shivering and thermal comfort scale in the pre-anesthetic area and post-anesthesia care unit.ResultsThe incidences of intraoperative hypothermia and postoperative hypothermia were similar in both groups (10.7% vs. 28.6%, P = 0.177; 10.7% vs. 10.7%, P = 1.000 respectively). Body temperature was higher in the 10-min pre-warming group (P = 0.003). Thermal comfort during the pre-warming period was higher in the 10-min pre-warming group (P < 0.001). However, postoperative thermal comfort and shivering grades of both groups were similar.ConclusionsTen minutes of pre-warming has no additional effect on the prevention of inadvertent perioperative hypothermia in intraoperative warming patients.

602 Managing Hypothermia in the Surgical Burn Patient

Abstract Introduction It is known, hypothermia, core body temperature at or below 36oC/96.8oF, can lead to dangerous complications for burn patients. Due to loss of their protective thermoregulation, burn patients are at an increased risk of hypothermia during surgery. Findings from a Quality Assurance audit revealed burn patients were returning from surgery hypothermic and hemodynamically unstable. There was little evidence of intra-operative temperature management in the electronic medical record (EMR) or reported to the nurse upon the patients’ return from the operating room (OR). Only 73% of patients had temperatures recorded during their surgery and of those, 40% had a drop of temperature &amp;gt;2 degrees from their baseline. The purpose of this collaborative evidence-based quality assurance project was to improve temperature management in the operating room and prevent hypothermia in the intra and post operative periods. Our aim was to develop warming methods pre-operatively that would establish a goal for keeping the patients’s temperature within 2 degrees of their baseline preoperative temperature during surgery. Methods A literature search obtained from CINAHL, Cochrane, EMBASE, and MEDLINE from 2010–2018, provided current surgical guidelines and evidence-based practices for managing surgical hypothermia in burn patients (levels of evidence I, III, V, &amp; VI). Recommendations from the burn unit staff for preoperative warming initiatives were listed and shared with the OR staff. Hemodynamic documentation, including core temperature, estimated blood loss, and intra-operative warming methods were monitored for twelve months after the Burn Unit Warming Protocol was implemented. Progress was reported quarterly in our Burn and Trauma Quality Committees. Results After implementing the Burn Unit Warming Protocol, temperature management of the burn patient improved. Intra-operative warming methods were initiated. Patients began returning from surgery warmer with improved hemodynamics. 96% of the patients had their temperatures recorded and managed intra-operatively. Of those patients, only 2.6% had a drop in temperature &amp;gt; 2 degrees from their pre-operative baseline. Conclusions Implementing a nurse-driven warming protocol from the pre-operative stage through surgery can aid in reducing post-operative hypothermia in burn patients. Applicability of Research to Practice Managing hypothermia will help reduce complications that can lead to increase morbidity and mortality in burn patients.

Short interruptions between pre-warming and intraoperative warming are associated with low intraoperative hypothermia rates.

Prevention of inadvertent hypothermia is recommended for procedures >30minutes because hypothermia increases the risk of myocardial ischemia, intraoperative blood loss, transfusion and wound complications. Therefore, short warming interruptions between pre-warming and intraoperative warming might result in lower hypothermia rates. The aim of this retrospective investigation was to determine whether the incidence of inadvertent intraoperative hypothermia was affected by the warming interruption. The lowest intraoperative body core temperature value and the warming interruption time were taken from anaesthesia records. Body core temperature was recorded continuously, and a patient was classified to be hypothermic if the lowest recorded temperature value was <36°C. Hypothermia rates and the correlation between warming interruption times and intraoperative hypothermia rates were calculated. Five thousand eighty-four patients were analysed. The intraoperative hypothermia rate was 15.3%. Nineteen patients (0.4%) had a recorded temperature of <35.0°C. An increase in forced-air warming interruption time was significantly associated with an increase in intraoperative hypothermia rates (P<.0001). Patients with interruptions in forced-air warming >20minutes showed significantly higher hypothermia rates than those with interruptions of ≤20minutes (P<.0001). Intraoperative hypothermia rates increased significantly with longer forced-air warming interruptions between pre-warming and intraoperative warming. Short warming interruptions can preserve the effect of pre-warming and are associated with low intraoperative hypothermia rates.

Prevalence of hypothermia on admission to recovery room remains high despite a large use of forced-air warming devices: Findings of a non-randomized observational multicenter and pragmatic study on perioperative hypothermia prevalence in France.

BackgroundDespite the availability of effective warming systems, the prevalence of hypothermia remains high in patients undergoing surgery. Occurrence of perioperative hypothermia may influence the rate of postoperative complications. Recommendations for the prevention of inadvertent perioperative hypothermia have been developed and are effective to reduce the frequency of perioperative hypothermia when professionals comply with. French Society of Anesthesiology (SFAR) decided to promote guidelines for the prevention of inadvertent hypothermia, and to conduct beforehand a pragmatic assessment of the prevalence of hypothermia in France. The hypothesis was that the rate of hypothermic patients (Tc<36°C) admitted to the RR remains high (around 50%), and that was the consequence of a warming device underutilization and/or was related to the type of health facilities.MethodsAn observational, prospective and multi-centric study was conducted in France between October 2014 and May 2016 among patients over 45 years undergoing non-cardiac, non-outpatient surgery with anesthesia lasting >30 minutes in 52 centers. Patients undergoing pulmonary or proctologic surgery and those having non-invasive procedures performed under general anesthesia (for example, digestive endoscopy) were excluded from our study. Patients being operated under plexus anesthesia alone, surgeries involving hemorrhaging or infection, and patients presenting at least one organ failure were also excluded. The primary endpoint was the percentage of patients with a core temperature (Tc) <36°C on admission to the recovery room (RR).ResultsAmong 893 subjects (median age 66.9 years), prevalence of hypothermia on admission to the RR was 53.5%. At least one warming system was used for 90.4% of the patients. Identified risk factors for Tc<36°C included age≥70 years (OR = 1.41 [CI95%: 1.02–1.94]), duration of anesthesia from 1 to 2 hours (OR = 1.94 [CI95%: 1.04–3.64]) and a decrease in Tc of >0.5°C between anesthesia induction and surgical incision (OR = 1.82 [CI95%: 1.15–2.89]). Only a combination of pre-warming and intraoperative warming prevented a Tc<36°C (OR = 0.48 [CI95%: 0.24–0.96]).ConclusionsThe prevalence of hypothermia among patients admitted to the RR remains high. Our results suggest that only the combination of pre-warming and intraoperative warming significantly decreases it.

PIN67 BUDGET IMPACT ANALYSIS OF THE IMPLEMENTATION OF A PRESURGICAL WARMING PROTOCOL TO EFFECTIVELY MANAGE SURGICAL PATIENT NORMOTHERMIA

Perform a budget impact analysis from a hospital perspective and estimate the cost savings achieved by adding a presurgical warming protocol to intra-operative warming, using a forced-air warming system to prevent inadvertent perioperative hypothermia (IPH). The one-year time horizon budget impact model is based on a new static decision-tree, modified from a model published by NICE in 2008. Based on IPH rate, the model allows a comparison of different patient temperature management strategies with associated material and adverse consequences costs. The current analysis uses IPH rates measured in a German hospital when implementing active pre-warming plus intra-operative warming versus intra-operative warming only. Adverse consequences of IPH, according to the NICE guidance, are grouped in surgical site infections (SSI), morbid cardiac events (MCE) and other complications, including the need of blood transfusions. The cost of the adverse consequences is monetized via increased length-of-stay (LOS). The model accounts for minor, intermediate and major surgery and four different age groups following German DRG-data to evaluate the relative risk for SSI and MCE. The costs of a bed-day on a surgical ward are derived from WHO estimates. The hypothermia rate from a retrospective study including 7786 patients having a surgery duration of at least 30 minutes under general anesthesia showed an IPH decrease from 12.4% to 5.1% with the introduction of active pre-warming in addition to intra-operative warming. For a hypothetical hospital conducting 1,000 surgical procedures per year (48% minor, 30% intermediate and 22% major), the implementation of pre-warming could result in total annual cost savings of 192,220€, corresponding to 60% direct costs decrease, 300 less hypothermia events and 342 days reduction in attributable LOS. The implementation of pre-warming is a cost saving intervention and should be recommended for effective management of patient normothermia.

Effect of comprehensive thermal insulation measures on body tempreture and stress index in patients with low body mass index of thoracic surgery

Objective To investigate the changes of body temperature and the effect of nursing intervention in patients with low body mass index (BMI<18.5 kg/m2) during thoracic surgery. Methods Sixty patients with low BMI who underwent thoracic surgery in the Operating Department of the 4th Hospital of Hebei Medical University from June 2016 to December 2018 were randomly divided into observation group and control group, with 30 cases in each group. In addition, 30 patients with normal BMI (18.5-23.0 kg/m2) who underwent thoracic surgery in the same period were selected as the normal group. The observation group adopted comprehensive thermal insulation measures during the operation, and the control group and the normal group adopted routine insulation measures. The patient's body temperature of three groups was compared at each time point: entering operation room, disinfection, body cavity exploration , cutting specimens, closing the chest, suture skin and exiting operation time. the occurrence of adverse reactions during surgery, the blood coagulation index and lactic acid in the peripheral blood before and at the end of surgery, and the peripheral blood inflammatory factor levels were also compared. Results There were no significant differences in body temperature between the three groups (P>0.05) . During the operation, the body temperature of the three groups decreased, and the recovery from the chest was restored. There were significant differences in body temperature between the three groups (P 0.05) . The coagulation and stress indexes of the observation group and the control group were significantly different from those of the normal group (P 0.05) . The coagulation, lactic acid and stress indexes of the three groups were significantly different before and after surgery (P<0.05) . There was a statistically significant difference in interleukin-6 (IL-6) levels before and after surgery (F=134.241, P< 0.001) ; there was an interaction between the intervention and the time, and the difference was statistically significant (Finteraction=12.202, P<0.001) . There were significant differences between the three groups in the interleukin-10 (IL-10) level group (between group F=7.792, P < 0.001) ; the difference of IL-10 levels before and after surgery was statistically significant (Ftime=112.121, P< 0.001) ; There was an interaction between the intervention and the time, and the difference was not statistically significant (Finteraction=2.990, P=0.055) . Conclusions Compared with patients with normal BMI thoracic surgery, patients with low BMI have abnormal blood coagulation and stress indicators before surgery, and are more likely to have intraoperative blood pressure drop and adverse reactions. Comprehensive intraoperative warming measures can effectively prevent hypothermia in patients with low BMI. Key words: Body mass index; Thoracic surgery; Body temperature; Coagulation function; Stress index

The application value of concept of enhanced recovery after surgery in patients with colorectal carcinoma after natural orifce specimen extraction surgery

Objective: To discuss the role of enhanced recovery after surgery (ERAS) in patients with colorectal carcinoma after natural orifce specimen extraction surgery (NOSES). Methods: From March 2017 to May 2018, 86 patients diagnosed with colorectal carcinoma and received NOSES at Tangshan Gongren Hospital were randomized to the control group and the observation group. Doctors utilized traditional interventions in the control group. In the observation group were orally administered with electrolyte solution for 12 hours before surgery, without gastrointestinal decompression tube routinely. Patients were fasting for 6 hours before surgery, 2 hours of water inhalation, and oral administration of 10% glucose 3 hours before surgery. During surgery, patients received intraoperative warming and controlled infusion volume. After operation, no drainage tube was placed, and multi-mode analgesia was used. The patient was given a fluid diet on the first day after surgery, and gradually transitioned to a normal diet. The intraoperative blood loss, number of lymph node dissection, operation time, hospitalization time, hospitalization expenses, first drinking time after surgery, diet time, exhaust time, time to get out of bed, pre-and post-operative self-rating anxiety scale (SAS) and self-rating depression scale (SDS) score, postoperative Barthel index and complication were compared between the two groups. Results: The intraoperative blood loss, number of lymph node dissection, and operation time were almost the same between the two groups (all P>0.05). The hospitalization time (6.8±1.2 d versus 8.5±1.5 d) and expenses (58±10 thousand Yuan versus 69±12 thousand Yuan) were significantly reduced in The first drinking time after surgery(1.31±0.35 d versus 2.28±0.24 d), diet time(1.8±0.4 d versus 3.0±0.4 d), exhaust time(2.4±0.5 d versus 2.9±0.6 d), and time to get out of bed (12.0±2.4 d versus 16.8±2.5 d) were all earlier in the observation group (all P<0.05). The SAS and SDS score before the operation were similar between the two groups (all P>0.05), while post-operative SAS (57±7 versus 69±8) and SDS (57±4 versus 62±9) score were significantly decreased in the observation group (all P<0.05). The incidence rates of complication after surgery was 7.0%(3/43) in the observation group, which was significantly lower than the control group (27.9%, 12/43, P=0.011). Conclusion: The combination of NOSES and EARS could reduce stress response, complications, recovery time and expense after surgery, while improving the quality of life in these patients.

Effect of intraoperative warming on muscle relaxation recovery of cisatracurium in patients undergoing gastrointestinal surgery

Objective: To investigate the effect of intraoperative warming on the postoperative relaxation recovery of cisatracurium in patients undergoing gastrointestinal surgery. Methods: Sixty ASA Ⅰ-Ⅱ patients, aged 20 to 60, undergoing elective gastrointestinal surgery in Cancer Hospital Chinese Academy of Medical Sciences from October, 2016 to March, 2019 were selected and they were randomly divided into two groups (n=30), N group and H group by random number table. N group was non-heat preserving group, and H group was heat preserving group. Tracheal intubation was induced by general anesthesia with cisatracurium 0.15 mg/kg, and the nasopharyngeal temperature were continuously monitored and recorded. Cisatracurium were infused 1-3 μg·kg(-1)·min(-1) by venous pump during operation with T1 at 1%-10% and stopped infusion 30 minutes before the end of surgery. The time when T1 recovered from 25% to 75%(muscle relaxation recovery index), and the time of T1 recovered to 25% to TOF ratios (TOFR, the ratio of the fourth muscle twitch height to T1 in TOF) recovery to 90% (full recovery time), cumulative drug use and surgery time were recorded. Results: There was no significant difference between the two groups in the cumulative drug dosage and operation time (P>0.05).The body temperature N group (35.7±0.2) ℃ was significantly lower than the H group (36.2±0.1) ℃ (t=13.940, P<0.01). The recovery index of N group (16.5±1.8) min was significantlyhigher than H group (10.5±2.1) min (t=12.094, P<0.01) and complete recovery time in N group (26.9±4.1) min was obviously longer than those in H group (15.0±2.9) (t=13.082, P<0.01). Conclusions: Patients with open gastrointestinal surgery are prone to hypothermia during surgery and heat protection is helpful to muscle relaxation recovery of cisatracurium.

Preventing Inadvertent Hypothermia in Patients Undergoing Major Spinal Surgery: A Nonrandomized Controlled Study of Two Different Methods of Preoperative and Intraoperative Warming

To evaluate if a Full Access Underbody (FAU) blanket used preoperatively and intraoperatively in patients undergoing major spinal surgery prevents hypothermia compared with current practice and to explore patients' experiences of comfort. A nonrandomized controlled trial. Sixty patients were included, 30 in each group. Temperature was assessed on arrival, after connecting to the bladder catheter, and at the start and end of surgery. In the FAU group, comfort was evaluated at arrival and after 10minutes of prewarming. The incidence of hypothermia at the start of surgery was significantly lower (relative risk [95% confidence interval], 0.28 [0.13 to 0.59]). Before prewarming, 77% felt comfortable, 20% cold, and 3% hot. After prewarming 60% felt comfortable, 37% hot, and 3% very hot. Patients using the FAU blanket had a 72% lower incidence of hypothermia at the start of the operation. Attention to thermal comfort during surgery is important.

493 The Intraoperative Esophageal Warming Device is Effective at Maintaining Optimal Core Temperature during Burn Surgery

493 The Intraoperative Esophageal Warming Device is Effective at Maintaining Optimal Core Temperature during Burn Surgery