Perioperative normothermia during major surgery: is it important?

Normothermia to Decrease Surgical Site Infection Risk: Silver Bullet or Fool's Gold? A Retrospective Cohort Study

PURPOSE

Surgical site infection (SSI) is the leading cause of nosocomial infections among surgical patients in the United States. Currently, there is compelling evidence suggesting that temperature dysregulation in surgical patients may be a risk factor for the development of SSI. We examined the relationship between perioperative hypothermia (PH) and SSI in a population of surgical patients with diabetes mellitus (DM).

METHODS

This retrospective cohort review was conducted on patients with a history of DM undergoing orthopaedic surgery at our institution between May 1, 2018, and April 1, 2022. Inclusion criteria were age older than 15 years, a history of DM or recent hemoglobin A1c concentration of ≥6.5%, and operation of at least 60 minutes under general anesthesia. Perioperative hypothermia was defined as an intraoperative temperature ≤ 35.5°C. Continuous variables were compared using the t-test and Wilcoxon rank-sum test. Categorical variables were compared using the chi-squared test. We constructed a multivariable logistic regression model to estimate SSI risk while controlling for demographic variables.

RESULTS

A total of 236 patients were included in the final analysis. The overall incidence of SSI was 5.93%. 99 patients (42%) experienced PH. No difference was observed in the risk of SSI between the normothermic and hypothermic cohorts. Among the 99 patients who experienced PH, increasing HbA1c was associated with increasing risk of SSI (OR = 2.39, 95% CI = 1.12 to 5.32, P-value = 0.0222). The multivariable logistic regression model had good discriminatory ability (c-statistic 0.74, 95% CI: 0.61 to 0.89) and good predictive accuracy (sensitivity 64%, specificity 73%).

DISCUSSION

PH is not an independent risk factor of SSI. However, in the presence of elevated HbA1c, PH may more than double the risk of SSI. Perioperative hypothermia may be an additive risk factor in the setting of poor glycemic control and potentially in the setting of other known risk factors.

Perioperative Hypothermia-A Narrative Review

Unintentional hypothermia (core temperature < 36 °C) is a common side effect in patients undergoing surgery. Several patient-centred and external factors, e.g., drugs, comorbidities, trauma, environmental temperature, type of anaesthesia, as well as extent and duration of surgery, influence core temperature. Perioperative hypothermia has negative effects on coagulation, blood loss and transfusion requirements, metabolization of drugs, surgical site infections, and discharge from the post-anaesthesia care unit. Therefore, active temperature management is required in the pre-, intra-, and postoperative period to diminish the risks of perioperative hypothermia. Temperature measurement should be done with accurate and continuous probes. Perioperative temperature management includes a bundle of warming tools adapted to individual needs and local circumstances. Warming blankets and mattresses as well as the administration of properly warmed infusions via dedicated devices are important for this purpose. Temperature management should follow checklists and be individualized to the patient's requirements and the local possibilities.

Developing an enhanced recovery after surgery program for oncology patients who undergo hip or knee reconstruction surgery

Enhanced recovery after surgery (ERAS) protocols are applied in orthopedic surgery and are intended to reduce perioperative stress by implementing combined evidence-based practices with the cooperation of various health professionals as an interdisciplinary team. ERAS pathways include pre-operative patient counselling, regional anesthesia and analgesia techniques, post-operative pain management, early mobilization and early feeding. Studies have shown improvement in the recovery of patients who followed an ERAS program after hip or knee arthroplasty, compared with those who followed a traditional care approach. ERAS protocols reduce post-operative stress, contribute to rapid recovery, shorten length of stay (LOS) without increasing the complications or readmissions, improve patient satisfaction and decrease the hospital costs. We suggest that the ERAS pathway could reduce the LOS in hospital for patients undergoing total hip replacement or total knee replacement. These programs require good organization and handling by the multidisciplinary team. ERAS programs increase patient's satisfaction due to their active participation which they experience as personalized treatment. The aim of the study was to develop an ERAS protocol for oncology patients who undergo bone reconstruction surgeries using massive endoprosthesis, with a view to improving the surgical outcomes.

Comparison of two forced-air warming devices during foot and ankle surgery: a randomised controlled trial

Inadvertent perioperative hypothermia is a frequent problem associated with surgical patients which can have significant consequences during surgery and in the immediate postoperative period. We compared 35 randomised patients using over vs. under body forced air heating. There were no statistically significant differences between some demographic and surgical parameters such as: age, weight, height, body mass index, length of anaesthesia and operation. Statistically significant differences were found between the patient's admission to the operating room and 30 minutes and the end of the procedure on the under body patients group. This study analyses a uniform population of patients (Foot and Ankle Surgery) previously not studied and supports the use of under body blankets.

Guidelines in Practice: Hypothermia Prevention

All patients are at risk for unplanned hypothermia in the perioperative practice setting. Adverse outcomes attributed to hypothermia include myocardial events, surgical site infections, poor wound healing, increased blood loss, and prolonged postanesthesia care unit stays. The AORN "Guideline for prevention of hypothermia" includes recommendations for measuring the patient's body temperature, selecting methods for prevention of unplanned hypothermia, and implementing the selected insulation and warming interventions. This article discusses guideline recommendations related to using a consistent temperature measurement method through all phases of perioperative care, assessing risk for hypothermia in all patients, and prewarming perioperative patients. A scenario provides an example in which an interdisciplinary facility team uses a gap analysis and a risk assessment to determine the process for implementing recommendations from this guideline. Perioperative RNs should review the entire guideline for additional information and for guidance when creating and updating policies and procedures related to unplanned hypothermia.

Enhanced recovery after surgery in gastric resections

INTRODUCTION

Enhanced recovery after surgery is a modality of perioperative management with the purpose of improving results and providing a faster recovery of patients. This kind of protocol has been applied frequently in colorectal surgery, presenting less available experience and evidence in gastric surgery.

METHODS

According to the RICA guidelines published in 2015, a review of the bibliography and the consensus established in a multidisciplinary meeting in Zaragoza on the 9th of October 2015, we present a protocol that contains the basic procedures of fast-track for resective gastric surgery.

RESULTS

The measures to be applied are divided in a preoperative, perioperative and postoperative stage. This document provides recommendations concerning the appropriate information, limited fasting and administration of carbohydrate drinks 2hours before surgery, specialized anesthetic strategies, minimal invasive surgery, no routine use of drainages and tubes, mobilization and early oral tolerance during the immediate postoperative period, as well as criteria for discharge.

CONCLUSIONS

The application of a protocol of enhanced recovery after surgery in resective gastric surgery can improve and accelerate the functional recovery of our patients, requiring an appropriate multidisciplinary coordination, the evaluation of obtained results with the application of these measures and the investigation of controversial topics about which we currently have limited evidence.

Enhanced Recovery After Surgery (ERAS) for gastrointestinal surgery, part 2: consensus statement for anaesthesia practice

Background

The present interdisciplinary consensus review proposes clinical considerations and recommendations for anaesthetic practice in patients undergoing gastrointestinal surgery with an Enhanced Recovery after Surgery (ERAS) programme.

Methods

Studies were selected with particular attention being paid to meta‐analyses, randomized controlled trials and large prospective cohort studies. For each item of the perioperative treatment pathway, available English‐language literature was examined and reviewed. The group reached a consensus recommendation after critical appraisal of the literature.

Results

This consensus statement demonstrates that anaesthesiologists control several preoperative, intraoperative and postoperative ERAS elements. Further research is needed to verify the strength of these recommendations.

Conclusions

Based on the evidence available for each element of perioperative care pathways, the Enhanced Recovery After Surgery (ERAS ^®) Society presents a comprehensive consensus review, clinical considerations and recommendations for anaesthesia care in patients undergoing gastrointestinal surgery within an ERAS programme. This unified protocol facilitates involvement of anaesthesiologists in the implementation of the ERAS programmes and allows for comparison between centres and it eventually might facilitate the design of multi‐institutional prospective and adequately powered randomized trials.

[Accelerated postoperative rehabilitation: multidisciplinary issue. Part 2]

AIM

To discuss the main aspects of multimodal method of accelerated postoperative rehabilitation (fast track surgery).

MATERIAL AND METHODS

The program of accelerated rehabilitation consists of minimization of surgical treatment's stressful influence on patient's organism in all stages of perioperative period. The method implies use of efficient preoperative management, minimally invasive operations, regional anesthesia and short-acting anesthetics, early postoperative rehabilitation.

RESULTS

The program improves the results of surgical treatment, reduces number of complications and cost of treatment, improves the "quality" of hospital stay and satisfaction of meeting with doctors.

A comprehensive literature review on hypothermia and early extubation following coronary artery bypass surgery

PURPOSE

The purpose of this study was to comprehensively review the literature addressing the physiological effects of hypothermia and its association with the appropriate core body temperature for extubation following coronary artery bypass surgery.

METHODS

The electronic databases MEDLINE, CINAHL and Web of Science via OVID were used to identify studies for the literature review. Search words used included 'core temperature', 'arrhythmia', 'cardiac', 'cardiac surgery', 'hypothermia', 'extubation', 'temperature', 'rewarming', and 'shivering'.

RESULTS

The literature search yielded 55 articles that met our inclusion criteria. No studies specifically identified the benefit of extubation at 36.5 ° C. Although temperatures varied, arrhythmias resulting from hypothermia were not reported until core body temperature dropped below 33 ° C.

CONCLUSION

This comprehensive literature review suggests extubation at lower temperatures (between 34 ° C and 36 ° C) may be viable if shivering and other factors known to contribute to myocardial stress can be controlled. These findings offer the possibility of earlier extubation which may promote beneficial health outcomes.

Does close temperature regulation affect surgical site infection rates?

The argument for close temperature control, to which regulatory bodies have held health systems in an effort to reduce the burden of hospital-acquired infections, is not fully supported by current evidence. The literature is complex on the topic, and overinterpretation of historical data supporting close temperature regulation does not preclude an important recognition of these early works' contribution to high-quality surgical care. Avoidance of hypothermia through the regular use of active rewarming should be a routine part of safe surgical care. The biochemical basis of emphasizing temperature regulation is sound, and ample evidence shows the frank physiologic derangements seen when biological processes occur at suboptimal temperature. It is also recognized that patients tend to do better when warmed during the perioperative period, suggesting that warming devices are an important and essential adjunct to good perioperative care. Clinicians, researchers, and policymakers must be careful in how they apply these well-supported findings to process metrics in an era of limited resources with increasingly stringent quality guidelines and outcomes measures. Discrete temperature targets in current measures are not supported by the existing literature. Not only do these targets artificially anchor clinicians to temperature values with an inadequate scientific basis but they demand intensive resources from health institutions that could potentially be better used on quality requirements with stronger evidence of their ultimate effect on patient care.

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.

[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.