Relationship between perfusion index and central temperature before and after induction of anesthesia in laparoscopic gastrointestinal surgery: A prospective cohort study

The perfusion index (PI) cutoff value before anesthesia induction and the ratio of PI variation after anesthesia induction remain unclear. This study aimed to clarify the relationship between PI and central temperature during anesthesia induction, and the potential of PI in individualized and effective control of redistribution hypothermia. This prospective observational single center study analyzed 100 gastrointestinal surgeries performed under general anesthesia from August 2021 to February 2022. The PI was measured as peripheral perfusion, and the relationship between central and peripheral temperature values was investigated. Receiver operating characteristic curve analysis was performed to identify baseline PI before anesthesia, which predicts a decrease in central temperature 30 minutes after anesthesia induction, and the rate of change in PI that predicts the decrease in central temperature 60 minutes after anesthesia induction. In cases with a central temperature decrease of ≥ 0.6°C after 30 minutes, the area under the curve was 0.744, Youden index was 0.456, and the cutoff value of baseline PI was 2.30. In cases with a central temperature decrease of ≥ 0.6°C after 60 minutes, the area under curve was 0.857, Youden index was 0.693, and the cutoff value of the PI ratio of variation after 30 minutes of anesthesia induction was 1.58. If the baseline PI is ≤ 2.30 and the PI 30 minutes after anesthesia induction is at least 1.58-fold the PI ratio of variation, there is a high probability of a central temperature decrease of at least 0.6°C within 30 minutes after 2 time points.

Enhanced recovery after surgery for primary hip and knee arthroplasty: a review of the evidence

Enhanced recovery after surgery (ERAS) protocols produce significant clinical and economic benefits in a range of surgical subspecialties. There is a long tradition of applying clinical pathways to the perioperative care of joint arthroplasty patients. Enhanced recovery after surgery represents the next step in the evolution of standardized care. To date, reports of full ERAS pathways for hip or knee arthroplasty are lacking. In this narrative review, we present the evidence base that can be usefully applied to constructing ERAS pathways for hip or knee arthroplasty. The history and rationale for applying ERAS to joint arthroplasty are explained. Evidence demonstrates improved outcomes after joint arthroplasty when a standardized approach to care is implemented. The efficacy of individual ERAS components in hip or knee replacement is considered, including preoperative education, intraoperative anaesthetic techniques, postoperative analgesia, and early mobilization after joint arthroplasty. Interventions lacking high-quality evidence are identified, together with recommendations for future research. Based on currently available evidence, we present a model ERAS pathway that can be applied to perioperative care of patients undergoing hip or knee arthroplasty.

The Effect of Operating Room Temperature on the Performance of Clinical and Cognitive Tasks

Introduction:

Operating room (OR) temperature may impact the performance of health care providers. This study assesses whether hot or cold room temperature diminishes the performance of OR personnel measured by psychomotor vigilance testing (PVT) and self-report scales.

Methods:

This prospective observational study enrolled surgical/anesthesia trainees, student registered nurse anesthetists, and certified registered nurse anesthetists. Each provider participated in a test of psychomotor function and a questionnaire using a self-report scale of personal comfort and well-being. The PVT and questionnaires were completed after 30 minutes of exposure to 3 different conditions (temperature of 21°C, 23°C, and 26°C).

Results:

The cohort of 22 personnel included 9 certified registered nurse anesthetists, 7 anesthesia/surgical trainees, and 6 student registered nurse anesthetists. Mean reaction time on the PVT was comparable among baseline (280 ± 47 ms), hot (286 ± 55 ms; P = 0.171), and cold (303 ± 114 ms; P = 0.378) conditions. On the self-report score (range, 1–21), there was no difference in the self-rated subjective performance between baseline and cold conditions. However, the self-rated subjective performance scale was lower (12 ± 6, P = 0.003) during hot conditions.

Discussion:

No difference was noted in reaction time depending on the temperature; however, excessive heat in the OR environment was associated with worse self-rated subjective performance among health care providers. Particularly, self-rated subjective physical demand and frustration were greater under hot condition.

Effectiveness of Early Warming With Self-Warming Blankets on Postoperative Hypothermia in Total Hip and Knee Arthroplasty

BACKGROUND

Hypothermia is an important complication in joint arthroplasty. Commonly, forced air warming (FAW) devices are used intraoperatively to maintain body temperature in patients undergoing surgery. However, it is believed that these convective warming systems could increase the risk of deep surgical site infections due to disruption of unidirectional downward laminar airflow. Conductive warming devices have no noticeable effect on ventilation airflow. Nevertheless, the effectiveness of the self-warming (SW) blanket, a novel conductive warming device, on postoperative hypothermia in elective joint arthroplasty is unknown.

PURPOSE

The purpose of this study was to evaluate the effectiveness of early warming with SW blankets in the prevention of postoperative hypothermia in elective total hip (THA) and knee arthroplasty (TKA) compared with FAW devices.

METHODS

Patients who underwent elective THA or TKA between May and June 2014 were assigned in the FAW or SW group. A total of 105 patients were enrolled into the study. In the FAW group, the FAW devices were applied after disinfection of the surgical site. In the SW group, the SW blankets were already applied in the orthopaedic department. The duration of warming with SW blankets before anesthetic induction was documented. The body temperature was measured preoperatively upon arrival in the orthopaedic department and postoperatively upon arrival in the postanesthesia care unit. The patient's body temperature was measured at the tympanic membrane, and hypothermia was defined as a body temperature of less than 35.5°C.

RESULTS

The SW blankets were applied for a median of 86.8 minutes (78.8-94.8) before anesthetic induction. Postoperative hypothermia was observed in 15 (31.3%) and eight (14.0%) patients in the FAW group and the SW group, respectively (p = .029). The median postoperative body temperature was 35.59°C (35.44-35.74) and 35.95°C (35.83-36.06) in the FAW group and the SW group, respectively (p < .001).

CONCLUSION

Early warming with SW blankets was more effective than FAW devices in the prevention of postoperative hypothermia in elective THA and TKA.

Intraoperative Hypothermia in Total Hip and Knee Arthroplasty

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common and successful orthopedic procedures, and as their frequency continues to increase substantially, the focus on limiting perioperative complications heightens. Intraoperative normothermia is recommended to minimize additional complications, but limited evidence exists regarding the effect of hypothermia on orthopedic patients. The purpose of this retrospective study was to determine the incidence of perioperative hypothermia in the setting of TKA and THA, and to evaluate its impact on complications and outcomes. The clinical records of 2580 consecutive patients who underwent TKA or THA at a single institution between January 1, 2011, and December 31, 2013 were reviewed. After excluding patients with complex or revision procedures, a total of 2397 patients comprised the study population. Patient demographic data, surgery-specific data, postoperative complications, length of hospital stay, and 30-day readmission were recorded. Patients with a mean intraoperative temperature less than 36°C were identified as hypothermic. Statistical analysis evaluated associations with hypothermia and the effect on complications and outcomes. The incidence of mean intraoperative hypothermia was 37%, 43.9%, and 32.6% for arthroplasty, THA, and TKA, respectively. General anesthesia was significantly associated with hypothermia (P<.001). Women and THA patients were at higher risk for hypothermia. In the arthroplasty and THA cohorts, longer operating room time and re-warmer use were associated with hypothermia (P=.010). Overall, hypothermia was associated with increased estimated blood loss, but no increase in associated transfusion was demonstrated (P=.006). Hypothermia was not associated with postoperative complications. [Orthopedics. 2017; 40(1):56-63.].

Efficacy of Prewarming With a Self-Warming Blanket for the Prevention of Unintended Perioperative Hypothermia in Patients Undergoing Hip or Knee Arthroplasty

PURPOSE

Unintended perioperative hypothermia (UPH) is a common and serious complication for patients undergoing anesthesia. The purpose of this study was to identify the incidence of UPH and evaluate the efficacy of a self-warming blanket on the drop in core temperature and risk of UPH in patients undergoing hip or knee arthroplasty.

DESIGN

A case-control study was used.

METHODS

Sixty patients were included. Thirty patients received prewarming with a self-warming blanket and forced-air warming intraoperatively; thirty patients received only forced-air warming intraoperatively.

FINDING

The incidence of UPH (<36°C) was identified in 13% of the patients in the prewarmed group and 43% of the patients in the control group. Mean core temperature in the prewarmed group was significantly higher and remained above 36°C in the perioperative period.

CONCLUSIONS

The study suggests that preoperative warming with a self-warming blanket reduces the incidence of UPH and decreases the drop in core temperature.

Tourniquet application during anesthesia: "What we need to know?"

Tourniquets are routinely and safely used in limb surgeries throughout the world. Tourniquet application alters normal physiology. Healthy patients tolerate these physiological changes well, but the physiological changes may not be well-tolerated by patients with poor cardiac function. This review discusses the physiological changes associated with tourniquet use, safe practice and provides the latest updates regarding tourniquet use. A systematic literature search of PubMed, MEDLINE, ScienceDirect, and Google Scholar was done. The search results were limited to the randomized controlled trials and systemic reviews. The papers are summarized in this review.

High incidence of postoperative hypothermia in total knee and total hip arthroplasty: a prospective observational study

Hypothermia, a body temperature of <36°C, has been shown to increase cardiac mortality, the incidence of postoperative infections, and the length of hospitalization following general surgery. However, studies assessing the incidence of hypothermia during primary total hip and total knee arthroplasty (THA and TKA) have not previously been demonstrated. In this prospective observational study, incidence of hypothermia was measured among 672 patients (415 underwent THA and 257 TKA). The incidence of hypothermia for THA and TKA was 26.3 and 28.0%, respectively. In conclusion, over a quarter of patients in this study are exposed to hypothermia. This study highlights the requirement for interventions to prevent peri-operative hypothermia.

The effects of surgery type and duration of tourniquet inflation on body temperature

OBJECTIVE

To identify factors related to the decrease in core body temperature after deflation of a pneumatic tourniquet during unilateral knee surgery under general anaesthesia.

METHODS

This observational study recruited 30 patients scheduled for arthroscopic surgery (group A) and 30 patients scheduled for open surgery (group O). Intraoperative oesophageal temperature was measured during tourniquet inflation and every minute for 10 min after deflation.

RESULTS

Core temperature decreased significantly after tourniquet deflation in both groups, the decrease being significantly greater in group A than in group O. Duration of tourniquet inflation and type of surgery were correlated with the temperature decrease.

CONCLUSIONS

In knee surgery using a tourniquet, the decrease in core body temperature after tourniquet deflation was closely related to the duration of tourniquet inflation and to arthroscopic rather than open surgery. Further studies are required to determine the effect of surgery type on temperature changes, independently of the duration of tourniquet inflation.