Mild hypothermia is associated with improved outcomes in patients undergoing microvascular head and neck reconstruction

Assessing the Influence of Intraoperative Core Body Temperature on Postoperative Venous Thromboembolism after Abdominal Wall Reconstruction

Background

Venous thromboembolism (VTE) is a dangerous postoperative complication after abdominal wall reconstruction (AWR). Intraoperative core body temperature has been associated with thrombotic events in other surgical contexts. This study examines the effects of intraoperative temperature on VTE rate after AWR.

Methods

A retrospective study was performed on AWR patients. Cohorts were defined by postoperative 30-day VTE. Intraoperative core body temperature was recorded as the minimum, maximum, and mean intraoperative temperatures. Study variables were analyzed with logistic regression and cutoff analysis to assess for association with VTE.

Results

In total, 344 patients met inclusion criteria. Fourteen patients were diagnosed with 30-day VTE for an incidence of 4.1%. The VTE cohort had a longer median inpatient stay (8 days versus 5 days, P < 0.001) and greater intraoperative change in peak inspiratory pressure (3 mm H2O versus 1 mm H2O, P = 0.01) than the non-VTE cohort. Operative duration [odds ratio (OR) = 1.32, P = 0.01], length of stay (OR = 1.07, P = 0.001), and intraoperative PIP difference (OR = 1.18, P = 0.045) were significantly associated with 30-day VTE on univariable regression. Immunocompromised status (OR = 4.1, P = 0.023; OR = 4.0, P = 0.025) and length of stay (OR = 1.1, P < 0.001; OR = 1.1, P < 0.001) were significant predictors of 30-day VTE on two multivariable regression models. No significant associations were found between temperature metrics and 30-day VTE on cutoff point or regression analysis.

Conclusions

Intraoperative core body temperature did not associate with 30-day VTE after AWR, though operative duration, length of stay, immunocompromised status, and intraoperative PIP difference did. Surgeons should remain mindful of VTE risk after AWR, and future research is warranted to elucidate all contributing factors.

Modified intraoperative temperature management prevents prolonged length of stay after head and neck surgery with free flap reconstruction

The present study aimed to investigate the association between intraoperative body temperature and prolonged length of stay (PLOS) after free flap reconstruction. A total of 753 patients who underwent head and neck surgery with free flap reconstruction were collected and randomly assigned into primary and validation cohorts. In the primary cohort, univariable and multivariable analyses were conducted to evaluate associations between intraoperative time-weighted (TW) temperature (TW average [TWA] temperature, TW hypothermia and TW hyperthermia) and PLOS. Nomograms were developed with and without intraoperative TW temperature, and validated in the validation cohort. Severe intraoperative TW hypothermia (OR = 1.004; 95% CI: 1.000, 1.007; p = 0.032) was identified as an independent risk factor for PLOS. Intraoperative TWA temperature and TW hypothermia showed linear related predictive effect for PLOS. The nomogram incorporating intraoperative TW temperature showed higher C-index (0.652, 95% CI: 0.591, 0.713) and improved net reclassification improvement for non-event (0.277, 95% CI: 0.118, 0.435; p < 0.001). Lower TWA temperature with mild TW hypothermia had a preventive effect on PLOS with a linear association, which may provide a modified range for intraoperative temperature management. The proposed nomogram incorporating intraoperative TW temperature could be used to develop personalized preventive strategies for PLOS after free flap reconstruction. IRB NUMBER: SYSEC-KY-KS-2022-037. CLINICAL TRIAL REGISTRATION NUMBER: Not applicable.

Incidence of Unintentional Intraoperative Hypothermia and Its Risk Factors in Oral and Maxillofacial Surgery: A Prospective Study

PURPOSE

Unintentional intraoperative hypothermia is a common complication in patients who undergo open surgery, increasing the risk of adverse outcomes. However, few studies have focused on intraoperative hypothermia during oral and maxillofacial surgery. Our study aimed to analyze the prevalence and risk factors of hypothermia in patients who underwent oral and maxillofacial surgery.

DESIGN

A prospective cohort study was conducted on 128 patients who underwent oral and maxillofacial surgery.

METHODS

This prospective study was conducted at West China Hospital of Stomatology between December 2020 and May 2021, and each patient was followed for at least 1-month postoperatively. Patients who underwent oral and maxillofacial surgery under general anesthesia, with at least 1-month follow-up were analyzed. The primary variable was intraoperative hypothermia, defined as core body temperature less than 36°C, measured using a tympanic thermometer during the surgery. We performed univariate and multivariate logistic regression analyses to identify the risk factors of unintentional intraoperative hypothermia.

FINDINGS

The mean age of the 128 patients was 31.0 ± 20.9 years, and there was a male predominance (53.1%), with male to female ratio of 1.13:1. Thirty-one patients (24.2%) developed hypothermia intraoperatively. Older age (OR = 1.068, 95% CI: 1.028-1.110, P = .001), lower weight (OR = 0.878, 95% CI: 0.807-0.955, P = .002), greater blood loss (OR = 1.003, 95% CI: 1.000-1.006, P = .034), and undergoing cancer surgery (OR = 0.210, 95% CI: 0.067-0.656, P = .007) were associated with intraoperative hypothermia.

CONCLUSIONS

Unintentional intraoperative hypothermia is common in patients who undergo surgery for oral cancer. Warming interventions to prevent intraoperative hypothermia for high-risk patients (older, lower weight, or more intraoperative bleeding) should be considered. Meanwhile, with careful nursing and rehabilitation instructions, intraoperative hypothermia does not lead to serious perioperative complications.

Impact of Intraoperative Hypothermia on Autologous Breast Reconstruction

OBJECTIVE

Studies have identified perioperative hypothermia as a risk factor for impaired wound healing, increased hospital length of stay, and surgical site infection. This study examines the effect of intraoperative hypothermia on postoperative outcomes in autologous microvascular free flap breast reconstruction.

METHODS

This was a retrospective review of 55 patients who experienced intraoperative hypothermia, defined as less than 35.0°C core body temperature and 99 normothermic patients who underwent autologous-based microvascular free flap breast reconstruction from 2013 to 2021. Demographics, comorbidities, smoking status, intraoperative warming devices, type of autologous reconstruction, hypothermia (and its duration), and length of surgery were collected. The outcomes assessed were infection rate, reoperation within 90 days, skin necrosis, wound healing complications, hematoma, seroma, and readmission within 90 days.

RESULTS

In the study population of 154 consecutive patients, 8.4% had type 1 or type 2 diabetes and 3.2% were current smokers. A total of 90.3% of patients (139) underwent deep inferior epigastric perforator flap reconstruction, 7.1% (11) superficial inferior epigastric artery flap reconstruction, and 4 (2.6%) another free flap type. A total of 35.7% of the patients (55) experienced intraoperative hypothermia defined as less than 35.0°C. In the hypothermic group, a higher proportion of patients had wound healing complications (52.7% vs 29.3%, P < 0.05), hematoma (16.4% vs 5.1%, P < 0.05), and readmission for postoperative complications (34.5% vs 14.1%, P < 0.05). There was also a trend toward higher incidence of seroma (7.3% vs 5.1%), surgical site infection (12.7% vs 9.1%), skin necrosis (12.7% vs 9.1%), and unplanned reoperation within 90 days (10.9% vs 7.1%). Further analysis via Firth logistic regression demonstrated intraoperative hypothermia predicted postoperative hematoma (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.17-11.60; P < 0.05), readmission within 90 days (OR, 3.20; 95% CI, 1.45-7.08; P < 0.05), and wound healing complications (OR, 2.69; 95% CI, 1.36-5.33; P < 0.05).

CONCLUSIONS

This study demonstrates that intraoperative hypothermia is a significant risk factor for postoperative wound healing complications, hematoma, and readmission within 90 days in autologous breast reconstruction. Because of a finite amount of donor sites, it is important to find ways to minimize the risk of postoperative complications. Our results support that maintaining strict normothermia during autologous breast reconstruction can significantly improve patient outcomes and reduce morbidity.

Pneumonia, urinary tract infection, bacteremia, and Clostridioides difficile infection following major head and neck free and pedicled flap surgeries

OBJECTIVES

Medical postoperative infections (MPIs) are important causes of morbidity following major head and neck free and pedicled flap reconstruction, but the incidence, time of onset, and microbiology are not well characterized.

MATERIALS AND METHODS

Medical records were reviewed of all head and neck flap surgeries performed 2009-2014 at an academic medical center. Postoperative pneumonia, urinary tract infection (UTI), bloodstream infection (BSI), Clostridioides difficile (CDI), and surgical site infections (SSI) were noted. Catheter-associated UTI (CAUTI), central line-associated BSI (CLABSI), and methicillin-resistant Staphylococcus aureus (MRSA) BSI were also evaluated.

RESULTS

Following 715 free (540) or pedicled (175) flap surgeries, 14.1% of patients developed ≥one MPI including pneumonia (10.6%), UTI (2.1%), BSI (0.7%), and CDI (2.4%). Onset was ≤7 days in 77%. The MPI incidence in free vs pedicled flaps was similar. By multivariate analysis, age ≥65 and clindamycin perioperative prophylaxis were associated with increased MPI risk, clean class surgery with decreased risk. The incidence of CAUTI (<1.0%), CLABSI (0.1%), and hospital-onset MRSA BSI (0.1%) was low. SSI rate (7.8% overall) was higher in patients who developed pneumonia (18.4 vs 6.6, p = 0.004). MPI cultures grew gram-negative bacilli or S. aureus in 75%. The length of stay was longer in patients who developed a MPI than those who did not (17.4 vs 10.4 days, p < 0.0001).

CONCLUSIONS

One-seventh of major head and neck flap surgeries were complicated by MPIs, three-quarters of infections developed within 1 week postoperatively. Gram-negative bacilli and S. aureus were the predominant pathogens.

Impact of Intraoperative Hypothermia on Microsurgical Free Flap Reconstructions

BACKGROUND

 Patients requiring microsurgical defect reconstruction are highly susceptible to intraoperative hypothermia, given oftentimes long operative times and exposure of large skin surface areas. While the impact of hypothermia has been extensively studied across various surgical fields, its role in the setting of microsurgical free flap reconstruction remains elusive. This study evaluates the effects of hypothermia on outcomes of free flap reconstructions.

METHODS

 Within 7 years, 602 patients underwent 668 microvascular free flap reconstructions. The cases were divided into two groups regarding the minimal core body temperature during free flap surgery: hypothermia (HT; < 36.0°C) versus normothermia (NT; ≥36.0°C). The data were retrospectively screened for patients' demographics, perioperative details, flap survival, surgical complications, and outcomes.

RESULTS

 Our data revealed no significant difference with regard to the rate of major and minor surgical complications, or the rate of revision surgery between both groups (p > 0.05). However, patients in the HT group showed significantly higher rates of total flap loss (6.6% [HT] vs. 3.0% [NT], p < 0.05) and arterial thrombosis (4.6% [HT] vs. 1.9% [NT], p < 0.05). This translated into a significantly longer hospitalization of patients with reduced core body temperature (HT: mean 16.8 days vs. NT: mean 15.1 days; p < 0.05).

CONCLUSION

 Hypothermia increases the risk for arterial thrombosis and total flap loss. While free flap transfer is feasible also in hypothermic patients, surgeons' awareness of core body temperature should increase. Taken together, we suggest that the mean intraoperative minimum temperature should range between 36 and 36.5°C during free flap surgery as a pragmatic guideline.

Effects of Anesthesia on Postoperative Recurrence and Metastasis of Malignant Tumors

It is difficult to control the recurrence and metastasis of malignant tumors; furthermore, anesthesia is considered one of the main influencing factors. There has been increasing clinical attention on the effects of anesthetic drugs and methods on postoperative tumor growth and metastasis. We reviewed the effects of anesthesia on tumor recurrence and metastasis; specifically, the effects of anesthetic agents, anesthesia methods, and related factors during the perioperative period on the tumor growth and metastasis were analyzed. This study can provide reference standards for rational anesthesia formulations and cancer-related pain analgesia protocols for surgical procedures in patients with malignant tumors. Moreover, it contributes toward an experimental basis for the improvement and development of novel anesthetic agents and methods.