The role of perioperative warming in surgery: a systematic review

Nurses' Awareness and Practices of Unintentional Perioperative Hypothermia Prevention: A Cross-Sectional Study

Unintentional perioperative hypothermia can cause potentially life-threatening complications. The aim of this study was to determine the awareness and practices of nurses regarding unintentional perioperative hypothermia prevention. The study was conducted at a teaching hospital in Gambia with descriptive cross-sectional design. A total of 53 nurses voluntarily participated in this study. The questionnaire used in this study was developed based on the American periOperative Registered Nurses (AORN) and National Institute for Health and Care Excellence perioperative hypothermia guidelines. Descriptive statistics, Pearson correlation, Student t-test, and one-way ANOVA were used in the analysis of data. The result of the study showed that nurses had high level of awareness of unintentional perioperative hypothermia prevention; however, practice levels were found to be low. Based on the results of the study, development of policies, implementation of the unintentional perioperative hypothermia prevention guidelines, and continuous education to improve nurses' knowledge and practices were recommended.

Perioperative Hypothermia in Surgical Patients: A Retrospective Cohort Analysis at a Busy District General Hospital

Introduction Perioperative hypothermia is a common yet underreported complication of surgery. It results from various factors, including cold operating theaters, anesthetic effects, environmental exposure, exposed tissues, and the administration of cold intravenous or irrigation fluids. This study aims to determine the incidence of perioperative hypothermia in a district National Health Service hospital to assess the feasibility of a randomized controlled trial (RCT) for interventions to prevent hypothermia. Methods This retrospective study included the data of 200 elective surgical patients at North Manchester General Hospital from June 1, 2022, to August 1, 2022. Inclusion criteria were elective general surgery, urology, breast, and gynecology patients aged 18 to 60 years. Exclusion criteria included emergency cases and patients younger than 18 or older than 60. Temperature measurement data were collected from the anesthesia records of the patients at six phases: preoperative, pre-induction, intraoperative, post-procedure, recovery room, and post-recovery. Data collection included specialty, surgery duration, and the use of intraoperative fluid warmers. Statistical analysis was performed using StatsDirect software (StatsDirect Ltd, Wirral, UK). Results Among the 200 patients, the overall incidence of hypothermia was 4% preoperatively, 5% pre-induction, 12% intraoperatively, 11% postoperatively, 8% in recovery, and 6% post-recovery. Intraoperative hypothermia incidence was significant, given that active warming was applied to patients with preoperative hypothermia. Regression analysis showed no correlation between intraoperative temperature and the use of intraoperative fluid warmers. Pre-induction temperature was the most statistically significant predictor of intraoperative hypothermia. Conclusions This study highlights the need for active interventions to recognize and prevent perioperative hypothermia in elective surgical patients. Active pre-warming of patients, regardless of surgery type and duration, is feasible and potentially beneficial. Future research should include an RCT comparing active and passive warming strategies to evaluate their effectiveness in improving perioperative outcomes.

Prewarming Parturients for Cesarean Section Does Not Raise Wound Temperature But Body Heat and Level of Comfort: A Randomized Trial

PURPOSE

Prewarming before cesarean section lowers the rates of surgical site infections (SSIs). We hypothesized that this effect is explained due to a higher core temperature resulting in a higher wound temperature.

DESIGN

We conducted an open-labeled randomized study with on-term parturients scheduled for elective cesarean section under spinal anesthesia. Participants were randomized into an intervention group (prewarming) and a control group.

METHODS

Core and wound temperature, comfort level, and examination results were taken at defined times until discharge from the postanesthesia care unit (PACU). There was a follow-up visit and interview 1 day after the procedure. The primary outcome was a difference in wound temperature. The secondary outcomes were differences in core temperature, patient comfort, blood loss, SSI, and neonatal outcome.

FINDINGS

We randomized a total of 60 patients, 30 per group. Prewarming lead to a significantly higher core temperature. Additionally, patient comfort was significantly higher in the prewarming group even after discharge from PACU. We did not find a difference in wound temperature, SSI, neonatal outcome, or blood loss.

CONCLUSIONS

Prewarming before cesarean section under spinal anesthesia maintains core temperature and improves patient comfort but does not affect wound temperature.

Prevention and management of perioperative hypothermia in adult elective surgical patients: A systematic review

BACKGROUND

Body temperature is tightly regulated with hormonal and cellular metabolism for normal functioning; however perioperative hypothermia is common secondary to anesthesia and surgical exposure.Prevention and maintaining body temperature should be started 1-2hrs before induction of anesthesia, to do this both active and passive warming system are effective to prevent complications associated with perioperative hypothermia.

METHODS

The aim of this systematic review is to develop a clear clinical practice protocol in prevention and management of perioperative hypothermia for elective adult surgical patients.The study is conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline 2020. After formulating clear criteria for the evidences to be included an appropriate method of searching was conducted by using the Pub Med, Google scholar and Cochrane library using the following MeSH terms: (inadvertent hypothermia AND anesthesia, hypothermia AND perioperative management and thermoregulation AND anesthesia) were used to draw evidences.After a reasonable amount of evidences were collected, appraisal and evaluation of study quality was based on WHO 2011 level of evidence and degree of recommendation. Final conclusions and recommendations are done by balancing the benefits and downsides of alternative management strategies for perioperative management of hypothermia.This systematic review registered with research registry unique identifying number (UIN) of "reviewregistry1253" in addition the overall AMSTAR 2 quality of this systematic review is moderate level.

DISCUSSION

Preserving a patient's body temperature during anesthesia and surgery is to minimize heat loss by reducing radiation and convection from the skin, evaporation from exposed surgical areas, and cooling caused by the introduction of cold intravenous fluids.

CONCLUSION

Hypothermia is least monitored complication during anesthesia and surgery results cardiac abnormalities, impaired wound healing, increased surgical site infections, shivering and delayed postoperative recovery, and coagulopathies.

Consensus statement for perioperative care in lumbar spinal fusion: Enhanced Recovery After Surgery (ERAS®) Society recommendations

BACKGROUND

Enhanced Recovery After Surgery (ERAS) evidence-based protocols for perioperative care have led to improvements in outcomes in numerous surgical areas, through multimodal optimization of patient pathway, reduction of complications, improved patient experience and reduction in the length of stay. ERAS represent a relatively new paradigm in spine surgery.

PURPOSE

This multidisciplinary consensus review summarizes the literature and proposes recommendations for the perioperative care of patients undergoing lumbar fusion surgery with an ERAS program.

STUDY DESIGN

This is a review article.

METHODS

Under the impetus of the ERAS® society, a multidisciplinary guideline development group was constituted by bringing together international experts involved in the practice of ERAS and spine surgery. This group identified 22 ERAS items for lumbar fusion. A systematic search in the English language was performed in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Systematic reviews, randomized controlled trials, and cohort studies were included, and the evidence was graded according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Consensus recommendation was reached by the group after a critical appraisal of the literature.

RESULTS

Two hundred fifty-six articles were included to develop the consensus statements for 22 ERAS items; one ERAS item (prehabilitation) was excluded from the final summary due to very poor quality and conflicting evidence in lumbar spinal fusion. From these remaining 21 ERAS items, 28 recommendations were included. All recommendations on ERAS protocol items are based on the best available evidence. These included nine preoperative, eleven intraoperative, and six postoperative recommendations. They span topics from preoperative patient education and nutritional evaluation, intraoperative anesthetic and surgical techniques, and postoperative multimodal analgesic strategies. The level of evidence for the use of each recommendation is presented.

CONCLUSION

Based on the best evidence available for each ERAS item within the multidisciplinary perioperative care pathways, the ERAS® Society presents this comprehensive consensus review for perioperative care in lumbar fusion.

Optimal Application of Forced Air Warming to Prevent Peri-Operative Hypothermia during Abdominal Surgery: A Systematic Review and Meta-Analysis

Patients who undergo abdominal surgery under general anesthesia develop hypothermia in 80–90% of the cases within an hour after induction of anesthesia. Side effects include shivering, bleeding, and infection at the surgical site. However, the surgical team applies forced air warming to prevent peri-operative hypothermia, but these methods are insufficient. This study aimed to confirm the optimal application method of forced air warming (FAW) intervention for the prevention of peri-operative hypothermia during abdominal surgery. A systematic review and meta-analysis were conducted to provide a synthesized and critical appraisal of the studies included. We used PubMed, EMBASE, CINAHL, and Cochrane Library CENTRAL to systematically search for randomized controlled trials published through March 2020. Twelve studies were systematically reviewed for FAW intervention. FAW intervention effectively prevented peri-operative hypothermia among patients undergoing both open abdominal and laparoscopic surgery. Statistically significant effect size could not be confirmed in cases of only pre- or peri-operative application. The upper body was the primary application area, rather than the lower or full body. These findings could contribute detailed standards and criteria that can be effectively applied in the clinical field performing abdominal surgery.

Prevalence of Inadvertent Perioperative Hypothermia and Associated Factors: A Cross-Sectional Study

Inadvertent perioperative hypothermia, defined as a body temperature <36.0°C, is a common outcome of anesthesia that can cause serious consequences to patients. The aim of this study is to determine the prevalence of inadvertent hypothermia among surgical procedures from two referral centers in Brazil and to identify sociodemographic, clinical, or surgery-related predictors of hypothermia. This is a cross-sectional study, conducted at two public hospitals in Brasília, Brazil. After the exclusion of 109 patients, 312 subjects (American Society of Anesthesiologists [ASA] physical status I-III) were enrolled from July 2016 through July 2018. The main outcome measures were the prevalence of hypothermia and its predictors. The mean age of the 312 patients was 43.2 (18.2) years (range 18-85 years), and 186 (59.6%) were female. The prevalence of inadvertent hypothermia was 56.7%. Predictors of hypothermia were perioperative chills (p = 0.026), patient's body temperature on arrival in the operating room (p < 0.001), diabetes (p < 0.001), ASA status III (p < 0.001), systolic blood pressure (p < 0.001), general anesthesia (p < 0.001), medical specialty (p < 0.001), fentanyl-based anesthesia (p = 0.002), and surgery time (p < 0.001). The multivariable model prediction model for hypothermia showed fairly good discrimination (area under the receiver operating characteristic: 79.0%, 95% confidence interval 68.0 to 80.1). Approximately 6 in 10 patients undergoing surgery developed inadvertent perioperative hypothermia. The risk of hypothermia is influenced by a myriad of factors that can be used in simple and low-cost predictive models with adequate discriminatory power.

The effects of active warming on perioperative inadvertent hypothermia in patients undergoing vitreoretinal surgery under local anesthesia

PURPOSE

Perioperative inadvertent hypothermia (PIH) is the decrease in core temperature below 36°C. We aimed to assess whether PIH develops in patients operated under local anesthesia (ULA) for vitreoretinal surgery in the operating room and investigate active warming efficacy.

METHODS

Seventy-two patients were divided into two groups: Group 1 contained unwarmed patients (n = 36), and Group 2, warmed patients (n = 36). The core temperatures, heart rate (HR), and mean arterial pressure (MAP) of the patients were measured at the beginning of surgery, after 20 min, 40 min, 1 h, at the end of the operation, and during the postoperative period.

RESULTS

PIH incidence was 44.6% in Group 1, whereas no hypothermia was observed in Group 2. Patient temperatures at 20 min (P = 0.001), 40 min (P < 0.001), 1 h (P < 0.001), the end of the operation (P < 0.001), and the postoperative period (P < 0.001) were significantly higher in Group 2 than in Group 1. Patient HRs at the end of the operation and during the postoperative period were significantly lower in Group 2 (P = 0.005) than in Group 1 (P < 0.001). The intraoperative 40th (P = 0.044) and 60th (P < 0.001) minutes, end of operation (P < 0.001), and postoperative MAP (P < 0.001) values of Group 1 were significantly higher than those of Group 2.

CONCLUSION

PIH may develop in patients operated ULA, especially with a low ambient temperature. Actively warming may help prevent the harmful effects of PIH.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Intraoperative surgical site infection control and prevention: a position paper and future addendum to WSES intra-abdominal infections guidelines

BACKGROUND

Surgical site infections (SSI) represent a considerable burden for healthcare systems. They are largely preventable and multiple interventions have been proposed over past years in an attempt to prevent SSI. We aim to provide a position paper on Operative Room (OR) prevention of SSI in patients presenting with intra-abdominal infection to be considered a future addendum to the well-known World Society of Emergency Surgery (WSES) Guidelines on the management of intra-abdominal infections.

METHODS

The literature was searched for focused publications on SSI until March 2019. Critical analysis and grading of the literature has been performed by a working group of experts; the literature review and the statements were evaluated by a Steering Committee of the WSES.

RESULTS

Wound protectors and antibacterial sutures seem to have effective roles to prevent SSI in intra-abdominal infections. The application of negative-pressure wound therapy in preventing SSI can be useful in reducing postoperative wound complications. It is important to pursue normothermia with the available resources in the intraoperative period to decrease SSI rate. The optimal knowledge of the pharmacokinetic/pharmacodynamic characteristics of antibiotics helps to decide when additional intraoperative antibiotic doses should be administered in patients with intra-abdominal infections undergoing emergency surgery to prevent SSI.

CONCLUSIONS

The current position paper offers an extensive overview of the available evidence regarding surgical site infection control and prevention in patients having intra-abdominal infections.

Comparison of Body Temperature, Normothermia, and Extubation Times of Patients Heated with Forced Air Warming Method Based on Whether Patients Underwent On-Pump or Off-Pump Coronary Artery Bypass Graft

AIM

This study aimed to compare the body temperature, normothermia, and extubation times of patients heated with forced air warming method based on whether they underwent on-pump or off-pump coronary artery bypass graft.

METHOD

This quasi-experimental study comprised 109 patients who underwent coronary artery bypass graft operation in the cardiovascular surgery department of a university hospital and a private hospital in Afyonkarahisar. Patients were divided into the following two groups: group 1 comprised 65 patients who underwent on-pump coronary artery bypass graft and group 2 comprised 44 patients who underwent off-pump coronary artery bypass graft. All patients included in the study were heated with forced air warming method. Preoperative and postoperative data were collected using the Patient Identification Form and the Patient Tracking Form, consisting of 16 items in total. Data were analyzed using the Statistical Package for the Social Sciences 18.0 software.

RESULTS

Even though the preoperative body temperature, postoperative first body temperature, second hour body temperature, and extubation time did not exhibit a significant difference depending on the operating method, a significant difference was observed regarding the first, third, fourth, and fifth hour body temperatures and time to reach normothermia based on the operating method (p<0.05). Notably, the off-pump group's body temperatures in the first, third, fourth, and fifth hours were higher compared with the on-pump group. Furthermore, the off-pump group reached normothermia (145.22±72.54 minutes) earlier or faster compared with the on-pump group (206.84±89.30 minutes). The body temperatures, extubation times, and normothermia were not observed to exhibit significant differences based on the gender (p>0.05). A statistically significant relation was not observed between the patient's body temperature and their age (p>0.05). However, a low but positive and significant (p<0.05) correlation was observed between the extubation times (r=0.197) and age, as well as time to reach normothermia (r=0.237) and age.

CONCLUSION

This study concluded that forced air warming method is an effective technique to minimize the time to regain normothermia among patients who underwent the on- and off-pump coronary artery bypass graft.

Intraoperative Hypothermia is Common, but not Associated With Blood Loss or Transfusion in Pediatric Posterior Spinal Fusion

BACKGROUND

Intraoperative hypothermia may be associated with increased blood loss due to the effects of temperature on clotting but this has not been evaluated in the setting of pediatric posterior spinal fusion (PSF). The purpose of this study was to determine if a correlation exists between intraoperative hypothermia and estimated blood loss (EBL) or transfusion requirements in pediatric patients undergoing PSF.

METHODS

A retrospective review of consecutive patients undergoing PSF for scoliosis at a single institution between 6/2004 and 3/2012 was performed. Exclusion criteria were fewer than 10 levels fused, anterior spinal fusion, and patients below 9 years old at time of surgery. Temperature was measured every 15 seconds using esophageal temperature probe. Input variable of hypothermia was analyzed as a binary variable Tmin ≤35°C at any point during anesthesia and as integrated temperature area under the curve (TAUC).

RESULTS

A total of 510 with an average age of 14.6 years (range, 9.0 to 24.3 y) met inclusion criteria. Totally, 56% (287/510) had idiopathic scoliosis (IS) and 44% (223/510) were non-IS. Hypothermia (Tmin≤35°C) was experienced by 45% (230/510) of all patients [48% (137/287) of IS; 42% (93/223) of non-IS]. A total of 63% (323/510) of patients were transfused with packed red blood cells (PRBC) [49% (141/287) of IS patients; 82% (182/223) of non-IS patients]. There was no correlation between Tmin≤35°C and transfusion of PRBC in all included patients (P=0.49); (IS patients P=0.45, non-IS patients P=0.61). There was no significant difference in EBL between patients who experienced hypothermia and those who did not (P=0.33; IS patients P=0.21, non-IS patients P=0.87). There was no significant correlation between TAUC and transfusion of PRBC for all patients (P=0.35), IS patients (P=0.26) and non-IS patients (P=0.54) or between TAUC and EBL (P=0.80); (IS patients P=0.57. non-IS patients P=0.62).

CONCLUSIONS

There was no significant correlation between intraoperative hypothermia and EBL or transfusion of PRBC in pediatric patients undergoing PSF.

LEVEL OF EVIDENCE

Level III.

Effect of "An Innovative Technology" Active Warming and Passive Warming on Unplanned Hypothermia During Perioperative Period: A Clinical Trial

Patients are at risk for unplanned hypothermia during the perioperative period due to many reasons, including anesthesia, low room temperature, cold intravenous fluid, and blood transfusion. This study was conducted to examine the effect of active and passive warming methods applied in patients during the perioperative period on unplanned hypothermia. This study is a case-control type study. The population of this study is composed of the patients hospitalized in surgical clinic and undergone abdominal region-related operations. Ninety patients were accidentally included in the study. The first group of patients were actively warmed during the perioperative period (carbon fiber resistive system - W-500D + 190 × 50 cm), the second group was passively warmed at least for 20 minutes during preoperative period (with blanket, socks etc.), and the third group was followed up as the control group. It was established that body temperature average of the active warming group has significantly increased during perioperative period (p < 0.001), and this temperature was significantly higher than the other groups until the third hour. It was found that the body temperature average of all groups was equal to 36.2 ± 0.26, 35.4 ± 0.49, and 35.2 ± 0.47, respectively, at the end of operation, and the difference among them was statistically significant (p ≤ 0.001). The active warming method applied with carbon fiber resistive system during the perioperative period is an effective method.

Efficacy of forced-air warming for preventing perioperative hypothermia and related complications in patients undergoing laparoscopic surgery: A randomized controlled trial

BACKGROUND

Perioperatively, unexpected hypothermia may cause adverse surgical outcomes. However, few studies have explored the efficacy of forced-air warming in patients undergoing laparoscopic surgery.

AIM/OBJECTIVE

To determine the efficacy of forced-air warming for preventing perioperative hypothermia and complications in patients undergoing laparoscopic surgery.

METHODS

A total of 127 participants undergoing laparoscopic thoracic or abdominal surgery were recruited between January and November 2015. Participants were randomly allocated to intervention (forced-air warming, n = 64) and control groups (passive insulation, n = 63). Oesophageal core temperature was measured during surgery, whilst tympanic core temperature was measured every 30 minutes preoperatively and in the postanaesthesia care unit. Levels of shivering and pain, amount of bleeding, and adverse cardiac events were measured before the transfer from the postanaesthesia care unit. The generalized estimating equation was used for data analysis.

RESULTS

The intervention group had better warming efficacy than the control group between 90 and 330 minutes during surgery. The intervention group had fewer complications than the control group in terms of intraoperative bleeding, time to rewarm to 36°C, pain levels, and shivering levels in the postanaesthesia care unit.

CONCLUSION

Forced-air warming can increase warming efficacy and reduce complications of perioperative hypothermia in patients undergoing laparoscopic surgery.

A Comparison of the Effects of Lung Protective Ventilation and Conventional Ventilation on Thermoregulation During Anaesthesia

Objective

During prolonged surgery, hypothermia is an unwanted condition that frequently develops and increases complication rates. It has been shown that positive end-expiratory pressure (PEEP) during mechanical ventilation reduces hypothermia development by providing earlier peripheral vasoconstriction. In the present study, an investigation was made of the effect of two different ventilation models on perioperative hypothermia development.

Methods

A total of 40 patients undergoing elective lumbar disc surgery were randomised to either the conventional group (Group C, n=20, tidal volume=10 mL kg^-1, PEEP=0 cm H₂O) or the lung protective ventilation group (Group P, n=20, tidal volume=6 mL kg^-1, PEEP=5 cm H₂O). Demographic data on gender, age, weight, height, preoperative-postoperative temperatures and haemodynamic values were recorded. The point where the forearm to fingertip skin temperature difference reached 0°C was determined as the peripheral vasoconstriction development. At this point, the core temperature was recorded as the thermoregulatory vasoconstriction threshold.

Results

Demographic characteristics of the patients and haemodynamic variables were similar between the groups. Preoperative and postoperative temperature gradients were not significantly different between the two groups (p=0.827). There was also no significant difference between the two groups in respect of the vasoconstriction threshold of the patients (p=0.432).

Conclusion

The study results showed that lung protective ventilation has no advantage in preserving the perioperative core temperature compared to conventional ventilation.

Perioperative warming, oxygen, and Ilomedin on oxygenation and healing in infrainguinal bypass surgery

BACKGROUND

Perioperative adjuncts are utilized across surgical specialities with the goal of improving patient outcomes. High-dose oxygen and extended warming are shown to increase wound collagen deposition during abdominal surgery. Prostacyclin is shown to improve limb salvage and patency rate in infrainguinal bypass (IIB) surgery. This study evaluated the impact of these adjuncts on healing and perfusion post IIB surgery.

METHODS

This randomized controlled study allocated patients undergoing IIB surgery into three treatment arms (perioperative high-dose oxygen, extended warming, and a synthetic prostacyclin) or a control group. The primary outcome was accumulation of hydroxyproline (OHP, collagen surrogate marker) as collected in polytetrafluoroethylene implants on day 5. Secondary outcomes included levels of growth factors and cytokines, and tissue oxygenation of the wound and foot as measured by hyperspectral technology and ankle-brachial pressure index. Clinical outcomes were observed to day 30, with long-term follow-up of 12 mo.

RESULTS

Seventy-one patients completed the study. Comparing treatment groups with the control at day 5, there were no differences in OHP, growth factors or cytokines levels, or improvement in tissue oxygenation at the surgical incision. However, there was more flow to the foot (HT-SUM (%) change) in the Ilomedin group compared to control (0% versus -14.6%, P = 0.045). HT-deoxy was higher at the peripheries in the oxygen and temperature groups, suggesting decreased tissue oxygenation.

CONCLUSIONS

The perioperative treatments did not dramatically improve oxygenation or healing of the surgical wound in IIB surgery; however, Ilomedin may result in greater flow to the peripheries.

Approach to Perioperative Hypothermia by Anaesthesiology and Reanimation Specialist in Turkey: A Survey Investigation

OBJECTIVE

The aim is to investigate the attitudes of anaesthesiologists working in Turkey on perioperative temperature monitoring.

METHODS

The questionnaire comprised 25 questions. Data were obtained through the completion of the questionnaire by hand or via the web.

RESULTS

Two hundred and four questionnaires were evaluated. Most physicians were working in government hospitals. We determined that 26% of physicians often use temperature monitoring and that physicians who works in university hospitals are significantly more common monitor the body temperature. There are different approachs on core temperature. The skin/axilla was the most preferred monitoring site; forced-air warming devices were the most common preferred heating systems. New-borns were the most commonly monitored group, and the Turkish Anaesthesiology and Reanimation Society guideline was the most commonly used reference. Physicians working in university or private hospitals were significantly more able to adjust the operating room temperature on demand.

CONCLUSION

There are different applications to prevent perioperative hypothermia. Although physicians are aware of the effects of anaesthesia on hypothermia and the contribution of hypothermia to complications, this awareness was not enough for them to make temperature monitoring a routine practice. To make temperature monitoring a standard practice, we believe that more studies should be conducted and that this issue needs to be more frequently addressed in congresses, anaesthesia conferences and particularly in residency training clinics.

Warming infusion improves perioperative outcomes of elderly patients who underwent bilateral hip replacement

BACKGROUND

This prospective, randomized, and controlled study was performed to determine the benefits of prewarmed infusion in elderly patients who underwent bilateral hip replacement.

METHODS

Between September 2015 and April 2016, elderly patients who underwent bilateral hips replacement that met the inclusion and exclusion criteria were included in this study. After inclusion, patients were randomized into one of the study groups: in the control group, patients received an infusion of fluid kept at room temperature (22-23°C); in the warming infusion group, patients received an infusion of fluid warmed using an infusion fluid heating apparatus (35°C). Postoperative outcomes, including recovery time, length of hospital stay, visual analogue scale (VAS) score, and postoperative complications rate of patients from both groups, were compared.

RESULTS

A total of 64 patients were included in our study (71.2 ± 7.6 years, 53.1% males), with 32 patients in the control group and 32 patients in warming infusion group. No significant difference was found in terms of demographic data and intraoperative blood transfusion rate between 2 groups (P > 0.05). Patients receiving a prewarmed infusion had a significantly shorter time to spontaneous breath, eye opening, consciousness recovery, and extubation than the control group (P < 0.05). In addition, significant differences were found in Steward score and VAS score between 2 groups (P < 0.05). Moreover, warming infusion group also showed an obviously decreased incidence of shivering and postoperative cognitive dysfunction (P < 0.05).

CONCLUSION

A prewarmed infusion could reduce the incidence of perioperative hypothermia and improve outcomes in the elderly during bilateral hip replacement.

Forced-Air Warming Provides Better Control of Body Temperature in Porcine Surgical Patients

Background: Maintaining normothermia during porcine surgery is critical in ensuring subject welfare and recovery, reducing the risk of immune system compromise and surgical-site infection that can result from hypothermia. In humans, various methods of patient heating have been demonstrated to be useful, but less evaluation has been performed in techniques to prevent hypothermia perioperatively in pigs. Methods: We compared body temperature regulation during surgery before and after modification of the ambient temperature of the operating laboratories. Three different methods of heating were then compared; a standard circulating water mattress, a resistive fabric blanket, and a forced hot air system. The primary measure was percentage of temperature readings outside a specification range of 36.7–40.0 °C. Results: Tighter control of the ambient temperature while using a circulating water mattress reduced the occurrence of out-of-specification body temperature readings from 20.8% to 5.0%, with most of these the result of hypothermia. Use of a resistive fabric blanket further reduced out-of-specification readings to 1.5%, with a slight increase in the occurrence of hyperthermia. Use of a forced air system reduced out-of-specification readings to less 0.1%. Conclusions: Maintenance of normothermia perioperatively in pig can be improved by tightly controlling ambient temperatures. Use of a resistive blanket or a forced air system can lead to better control than a circulating water mattress, with the forced air system providing a faster response to temperature variations and less chance of hyperthermia.

The effect of 30 to 60 minutes of forced-air pre-warming on maintaining intraoperative core temperatures during the first hour post-anesthesia induction in adult patients undergoing general anesthesia: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this review is to identify the effectiveness of 30 to 60 minutes of forced-air pre-warming on maintaining intraoperative core temperatures in adult patients undergoing general anesthesia. The review question will focus on the effects of forced-air pre-warming on preventing redistribution hypothermia in the first hour post induction of anesthesia, which is considered the most critical due to an internal core-to-peripheral redistribution of body heat and subsequent loss of heat to the operative room surroundings.

Perioperative Warming in Surgical Patients: A Comparison of Interventions

The four arm study investigates how use of a preoperative forced-air warming blanket and adjustment of ambient surgical room temperature may contribute to prevention of perioperative hypothermia. Active warming interventions may prevent the drop in core temperature that occur as a result of surgical anesthesia. Core body temperatures from a convenience sample of 220 adult surgical patients were sequentially monitored in the preoperative, intraoperative, and post-anesthesia care units (PACU) while receiving: (a) routine surgical care, (b) application of preoperative forced-air warming blanket, (c) application of preoperative forced-air warming blanket with adjustment of ambient surgical room temperatures, or (d) adjustment of ambient surgical room temperature only. Sample characteristics were evenly distributed among the four groups. There were no statistical differences in PACU core body temperatures. The application of forced-air warming blankets and room temperature adjustment interventions were not more effective than current practice in preventing perioperative hypothermia.

Impact of warming blood transfusion and infusion toward cerebral oxygen metabolism and cognitive recovery in the perioperative period of elderly knee replacement

Objective

This study aims to observe the impact of the temperature of blood transfusion and infusion toward the perioperative cerebral oxygen metabolism and the postoperative cognitive recovery.

Methods

Eighty patients of knee replacement under epidural and general anesthesia were randomly divided into warming blood transfusion and infusion (WBI) group (n = 40) and control group (n = 40). The changes of nasopharyngeal temperature, middle cerebral artery blood flow, CERO₂, and SjVO₂ of the two groups were recorded at each time point for the assessment of the postoperative overall quality of recovery and cognitive recovery situation.

Results

The nasopharyngeal temperatures of the two groups at different time points after transfusion were significantly lower than that at T1, and there was a significant difference between the two groups (P < 0.05). The CERO₂ values of the two groups at T3 were significantly higher than at T1, while the SjVO₂ values were significantly decreased (P < 0.01).

Conclusion

The WBI can significantly reduce the occurrence of the perioperative hypothermia, while it has no significant effect toward cerebral oxygen metabolism, postoperative overall recovery, and recovery of cognitive function.

Surgical-site infection after abdominal wall closure with triclosan-impregnated polydioxanone sutures: results of a randomized clinical pathway facilitated trial (NCT00998907)

BACKGROUND

Wound infections after abdominal surgery are still frequent types of nosocomial infections. Suture materials might serve as a vehicle for mechanical transport of bacteria into the surgical wound. To prevent the contamination of suture material in surgical wounds, triclosan-coated suture materials with antibacterial activity was developed. We here report a prospective randomized pathway controlled trial investigating the effect of triclosan impregnation of polydioxanone sutures used for abdominal wall closure on the rate of surgical-site infections.

PATIENTS AND METHODS

A total of 856 patients included in this trial underwent a standardized clinical pathway documented abdominal wall closure after abdominal surgery. Patients were randomized to have the fascia closed with either a 2-0 polydioxanone loop or a triclosan impregnated 2-0 polydioxanone loop. The primary outcome was the number of wound infections. Risk factors for poor wound healing were collected prospectively to compare the two groups.

RESULTS

When a PDS loop suture for abdominal wall closure was used, 42 (11.3%) patients with wound infections were detected. The number of patients with wound infections decreased significantly to 31 when the PDS plus for abdominal wall closure was used (6.4%, P < .05). Other risk factors for the development of side infections were comparably in the two groups.

CONCLUSION

This clinical pathway facilitated trial shows that triclosan impregnation of a 2-0 polydioxanone closing suture can decrease wound infections in patients having a laparotomy for general and abdominal vascular procedures.

[Evidence-based practices published in Brazil: identification and analysis studies about human health prevention]

Integrative review of Brazilian studies about evidence-based practices (EBP) about prevention in human health, published in Web of Science/JCR journals, between October 2010 and April 2011. The aim was to identify the specialties that most accomplished these studies, their foci and methodological approaches. Based on inclusion criteria, 84 studies were selected, mainly published in public health journals, focusing on primary care and also addressing clinical issues and different specialties. Prevention foci and methodological approaches also varied, with a predominance of systematic reviews without meta-analysis. The results indicate that there is no single way to conceptualize and practice EBP in the field of prevention, and that its application may not only serve to obtain indisputable evidence to equip intervention actions. This endless knowledge area is under construction, with a view to the analysis and further understanding of health phenomena.

Complex modulation of TRPM8 cold receptor by volatile anaesthetics and role in complications of general anaesthesia

The mechanisms by which volatile general anaesthetics (VAs) produce a depression of central nervous system are beginning to be better understood, but little is known about a number of side effects. Here, we show that the cold receptor, TRPM8, is complexly modulated by clinical concentration of VAs in dorsal root ganglion neurons and HEK-293 cells heterologously expressing TRPM8. VAs produced transient enhancement of TRPM8 via a depolarizing shift of its activation towards physiological membrane potentials, followed by a sustained TRPM8 inhibition. Stimulatory action of VAs engaged molecular determinants distinct from those used by the TRPM8 agonist. Transient TRPM8 activation by VAs could explain such side effects as inhibition of respiratory drive, shivering and cooling sensation during the beginning of anaesthesia, whereas the second phase of VA action associated with sustained TRPM8 inhibition may be responsible for hypothermia. Consistent with this, both hypothermia and inhibition of respiratory drive induced by VAs are partially abolished in TRPM8-null animals. Thus, we propose TRPM8 as a new clinical target for diminishing common and serious complications of general anaesthesia.

[Do anesthetic techniques influence postoperative outcomes? Part II]

The knowledge of the influence of anesthetic techniques in postoperative outcomes has opened a large field of research in recent years. In this second part, we review some of the major controversies arising from the literature on the impact of anesthetic techniques on postoperative outcomes in 6 areas: postoperative cognitive dysfunction, chronic postoperative pain, cancer recurrence, postoperative nausea/vomiting, surgical outcomes, and resources utilization. The development of protective and preventive anesthetic strategies against short and long-term postoperative complications will probably occupy an important role in our daily anesthetic practice. Dynamic postoperative pain control has been confirmed as one of the basic requirements of accelerated postoperative recovery programs ("fast-track surgery"), and it is also a preventive factor for development of chronic postoperative pain. The weight of anesthetic technique on postoperative immunosuppression is to be defined. The potential influence of anesthesia on cancer recurrence, is a highly controversial area of research. The classic pattern of perioperative fluid therapy may increase postoperative complications. On the other hand, the maintenance of normoglycemia and normothermia was associated with a decreased postoperative morbidity. The high volume of surgical procedures means that the adequacy of human, organizational and technological resources have a major impact on overall costs.

[Management of peri-operative hypothermia]

Hypothermia (body temperature under 36°C) is the thermal disorder most frequently found in surgical patients, but should be avoided as a means of reducing morbidity and costs. Temperature should be considered as a vital sign and all staff involved in the care of surgical patients must be aware that it has to be maintained within normal limits. Maintaining body temperature is the result, as in any other system, of the balance between heat production and heat loss. Temperature regulation takes place through a system of positive and negative feedback in the central nervous system, being developed in three phases: thermal afferent, central regulation and efferent response. Prevention is the best way to ensure a normal temperature. The active warming of the patient during surgery is mandatory. Using warm air is the most effective, simple and cheap way to prevent and treat hypothermia.

Incisional hernia after abdominal closure with slowly absorbable versus fast absorbable, antibacterial-coated sutures

BACKGROUND

Incisional hernia remains among the most common complications after midline incision of the abdominal wall. The role of the suture material used for abdominal wall closure remains controversial. To decrease bacterial adherence to surgical sutures, braided suture materials with antibacterial activity (Vicryl plus, Ethicon, Inc) were developed. This is the first study to analyze long-term results using an antibacterial-braided suture material for abdominal wall closure in a large clinical trial.

METHODS

To analyze the effects of Triclosan-coated suture material (Vicryl plus) on the development of incisional hernia, we performed a 36-month follow-up of 1,018 patients who had a primary midline incision for elective abdominal surgery. In the first time period, a PDS II loop suture was used. In the second observation period, we used Vicryl plus. All variables were recorded prospectively in a database. The primary outcome was the number of incisional hernias. Risk factors for the development of incisional hernias were collected prospectively to compare the 2 groups.

RESULTS

The overall incisional hernia rate in the 36-month follow-up period was 14.6%. Analyzing the influence of the suture material used on the development of incisional hernia, we did not find differences between the 2 groups (PDS II, 14%; Vicryl plus, 15.2%). In the multivariate analysis of possible factors in the study population, only body mass index (BMI) showed a significant influence on the development of incisional hernias. Despite the incidence of wound infections being less in the Vicryl plus group (6.1% vs 11.9%; P < .05), there were no difference in incidence of incisional hernia between the 2 groups.

CONCLUSION

Fast absorbable sutures with antibacterial coating (Tricosan) do not increase the hernia rate after midline abdominal incision compared with slowly absorbable sutures, when wound infection rates are decreased by coating the fast absorbable suture with Triclosan. The development of incisional hernia is significantly increasing in patients with a BMI >30 kg/m(2).

[Evidence-based practices published in Brazil: identification and analysis of their types and methodological approches]

This is an integrative review of Brazilian studies on evidence-based practices (EBP) in health, published in ISI/JCR journals in the last 10 years. The aim was to identify the specialty areas that most accomplished these studies, their foci and methodological approaches. Based on inclusion criteria, 144 studies were selected. The results indicate that most EBP studies addressed childhood and adolescence, infectious diseases, psychiatrics/mental health and surgery. The predominant foci were prevention, treatment/rehabilitation, diagnosis and assessment. The most used methods were systematic review with or without meta-analysis, protocol review or synthesis of available evidence studies, and integrative review. A strong multiprofessional expansion of EBP is found in Brazil, contributing to the search for more selective practices by collecting, recognizing and critically analyzing the produced knowledge. The study also contributes to the analysis itself of ways to do research and new research possibilities.