Wound tissue oxygen tension predicts the risk of wound infection in surgical patients

PErioperative respiratory care aNd outcomes for patients underGoing hIgh risk abdomiNal surgery (PENGUIN): a randomised international internal pilot trial

Background

Infections are a common complication of abdominal surgery in low- and middle-income countries (LMICs). The role of a high fraction of inspired oxygen (FiO2) and chlorhexidine mouthwash in preventing post-operative infections is unconfirmed.

Methods

Internal pilot phase of an international outcome assessor-blinded, 2x2 factorial randomised trial of patients aged ≥10-years undergoing midline laparotomy in LMIC hospitals. The main trial objectives are to compare the clinical effectiveness of preoperative 0.2% chlorhexidine mouthwash in preventing pneumonia versus no mouthwash, and 80-100% perioperative FiO2 to prevent surgical site infection (SSI) versus 21-35% FiO2. This 12-month internal pilot assessed feasibility of hospital site opening, patient recruitment, intervention adherence, patient follow-up and safety. Patients were randomised in a 1:1:1:1 ratio to the four intervention group combinations and followed up for 30 days.

Results

We recruited 927 patients from seven hospitals in India and South Africa over 12 months from November 2020. There were 907 adults (97.8%) and 20 children aged ten or over (2.2%): 89/927 (9.6%) patients died. Site opening reached 70% of our target (7/10) hospitals, and patient recruitment 107% (927/870). 917/927 (99%) patients in the mouthwash arm, and 840/927 (91%) patients in the oxygen arm received the allocated intervention. Lower adherence to the oxygen intervention related mainly to clinically necessary FiO2 increases in the 21-35% FiO2 arm. 30-day follow-up was completed appropriately for 924/927 (99%) patients. and was performed by a masked assessor for all patients. There were no reported safety events.

Conclusion

This pilot showed the feasibility and safety of a major phase III trial in post-operative infection prevention in LMICs.

Trial registration

ClinicalTrials.gov NCT04256798.

Effects of postoperative hand therapy in patients with Dupuytren's disease : A prospective hyperspectral imaging study

BACKGROUND

Hyperspectral imaging enables noninvasive evaluation of the microcirculation, which affects wound healing. In patients with Dupuytren's disease the microcirculation should be improved in order to achieve good clinical results and reduce the risk of recurrence. The aim of the study was to evaluate the microcirculatory effectiveness of postoperative hand therapy in patients with Dupuytren's disease after partial fasciectomy.

METHODS

In an inpatient hospital setting 35 patients with Dupuytren's disease were investigated before and after partial fasciectomy. Standardized hand therapy was performed after surgery. Its effects on superficial and deep oxygenation, tissue hemoglobin index and tissue water index were assessed using hyperspectral imaging at 3 regions of interest (ROI) within the first 2 postoperative days. For image evaluation, three ROIs were placed manually within the palm, the fingertip of the affected digit (fourth or fifth digit) and a fingertip of a control digit (unaffected, second digit of the same hand) using the vendor's software (TivitaTM Tissue Suite, Diaspective Vision, Germany).

RESULTS

Superficial oxygenation increased 1 day after surgery and after hand therapy. The tissue water index decreased on the second postoperative day.

CONCLUSION

Hyperspectral Imaging demonstrates that postoperative hand therapy effectively improves perfusion and oxygenation in the hands of patients with Dupuytren's disease and additionally reduces edema.

Evaluation of anastomotic blood supply during digestive tract reconstruction with the use of the oxygen saturation index: A pooling up analysis

PURPOSE

Anastomotic leakage (AL) is one of the most serious clinical complications in digestive tract reconstruction (DTR) surgery, and it is currently hypothesized that this may be related to insufficient anastomotic blood supply. Thus, Therefore, we aimed to assess the ability of tissue oxygen saturation(StO2) as a measure to evaluate anastomotic blood supply.

METHODS

A comprehensive literature search was performed using Embase, PubMed and Cochrane Library. StO2 was used as an evaluation index of anastomotic blood supply after DTR to analyze the potential association between this index and the occurrence of AL in the postoperative period.

RESULTS

A total of eleven articles involving 867 participants were included in this systematic review and meta-analysis. After pooling the standardized mean difference (SMD) and 95% confidence intervals (Cls), low StO2 was found to be an independent risk factor for AL (P < 0.00001; 95%CI: 1.02 [0.53-1.51]). The mean StO2 in the AL group (62.3%) was significantly lower than that in the non-AL group (74.3%); AL incidence increased with the reduction of StO2 to a certain value to 201.8% and 338.1% respectively.

CONCLUSION

Oxygen saturation index can be utilized in DTR to accurately and quantitatively evaluate the anastomotic blood supply to reduce the probability of postoperative AL.

Creating an Extremely Long-lasting Neuroischemic Wound Model

In wound study and dressing development, a lack of a suitable animal model that can recapitulate the complex pathophysiology of human chronic wounds has been a major hurdle. Chronic wounds are defined as wounds that heal with a significant delay, usually over a period >2-3 months, but no current animal wound model has such a longischemia. After a longexploration, our group has developed an animal wound model with ischemia and nerve damage lasting for at least 6 months. This model can be easily combined with other conditions such as diabetes and aging for wound mechanistic study and critical testing of dressings. This report presents the method that has significant utility in evaluating therapies that could become the future standard for screening all new wound dressings.

Hypothermia: Pathophysiology and the propensity for infection

Hypothermia in combination with infection presents a complex challenge in clinical and battlefield medicine. Multifaceted physiological and immunological consequences of hypothermia drastically change the risk, progression, and treatment of a concomitant infection. Managing hypothermia and infection in extreme cold settings is particularly relevant in an era with increased risk of military operations in Polar climates. Here, we discuss the elevated instance of infection during accidental and therapeutic hypothermia and speculate how a compromised immune system may contribute. We focus on skin and soft tissue infections and sepsis, which are among the serious infectious complications of hypothermia and battlefield injuries. We also present the challenges associated with treating infections under hypothermic conditions. Finally, we advocate for a renewed focus on identifying causal relationships between hypothermia and infection risk and assessing established infection treatment regiments in hypothermic patients to enhance trauma management and survival outcomes in hypothermia-related injuries.

Cardiac output-guided haemodynamic therapy for patients undergoing major gastrointestinal surgery: OPTIMISE II randomised clinical trial

OBJECTIVES

To evaluate the clinical effectiveness and safety of a perioperative algorithm for cardiac output-guided haemodynamic therapy in patients undergoing major gastrointestinal surgery.

DESIGN

Multicentre randomised controlled trial.

SETTING

Surgical services of 55 hospitals worldwide.

PARTICIPANTS

2498 adults aged ≥65 years with an American Society of Anesthesiologists physical status classification of II or greater and undergoing major elective gastrointestinal surgery, recruited between January 2017 and September 2022.

INTERVENTIONS

Participants were assigned to minimally invasive cardiac output-guided intravenous fluid therapy with low dose inotrope infusion during and four hours after surgery, or to usual care without cardiac output monitoring.

MAIN OUTCOME MEASURES

The primary outcome was postoperative infection within 30 days of randomisation. Safety outcomes were acute cardiac events within 24 hours and 30 days. Secondary outcomes were acute kidney injury within 30 days and mortality within 180 days.

RESULTS

In 2498 patients (mean age 74 (standard deviation 6) years, 57% women), the primary outcome occurred in 289/1247 (23.2%) intervention patients and 283/1247 (22.7%) usual care patients (adjusted odds ratio 1.03 (95% confidence interval 0.84 to 1.25); P=0.81). Acute cardiac events within 24 hours occurred in 38/1250 (3.0%) intervention patients and 21/1247 (1.7%) usual care patients (adjusted odds ratio 1.82 (1.06 to 3.13); P=0.03). This difference was primarily due to an increased incidence of arrhythmias among intervention patients. Acute cardiac events within 30 days occurred in 85/1249 (6.8%) intervention patients and 79/1247 (6.3%) usual care patients (adjusted odds ratio 1.06 (0.77 to 1.47); P=0.71). Other secondary outcomes did not differ.

CONCLUSIONS

This clinical effectiveness trial in patients undergoing major elective gastrointestinal surgery did not provide evidence that cardiac output-guided intravenous fluid therapy with low dose inotrope infusion could reduce the incidence of postoperative infections. The intervention was associated with an increased incidence of acute cardiac events within 24 hours, in particular tachyarrhythmias. Based on these findings, the routine use of this treatment approach in unselected patients is not recommended.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN39653756.

Super-Obesity is Associated With an Increased Risk of Complications Following Primary Total Knee Arthroplasty

BACKGROUND

Obesity, defined as a body mass index (BMI) ≥ 30, is an ever-growing epidemic, with > 35% of adults in the United States currently classified as obese. Super-obese individuals, defined as those who have a BMI ≥ 50, are the fastest-growing portion of this group. This study sought to quantify the infection risk as well as the incidence of surgical, medical, and thromboembolic complications among super-obese patients undergoing total knee arthroplasty (TKA).

METHODS

An all-payer claims database was used to identify patients who underwent elective, primary TKA between 2016 and 2021. Patients who had a BMI ≥ 50 were compared to those who had a normal BMI of 18 to 25. Demographics and the incidence of 90-days postoperative complications were compared between the 2 groups. Univariate analysis and multivariable regression were used to assess differences between groups.

RESULTS

In total, 3,376 super-obese TKA patients were identified and compared to 17,659 patients who had a normal BMI. Multivariable analysis indicated that the super-obese cohort was at an increased postoperative risk of periprosthetic joint infection (adjusted odds ratio [aOR] 3.7, 95% confidence interval [CI]: 2.1 to 6.4, P < .001), pulmonary embolism (aOR 2.2, 95%-CI: 1.0 to 5.0, P = .047), acute respiratory failure (aOR 4.1, 95%-CI: 2.7 to 6.1, P < .001), myocardial infarction (aOR 2.5, 95%-CI: 1.1 to 5.8, P = .026), wound dehiscence (aOR 2.3, 95%-CI: 1.4 to 3.8, P = .001), and acute renal failure (aOR 3.2, 95%-CI: 2.4 to 4.2, P < .001) relative to patients who have normal BMI.

CONCLUSIONS

Super-obese TKA patients are at an elevated risk of postoperative infectious, surgical, medical, and thromboembolic complications. As such, risk stratification, as well as appropriate medical management and optimization, is of utmost importance for this high-risk group.

Effects of body mass index on mortality in elderly patients with hip fractures

Hip fractures remain a substantial health concern, particularly among elderly individuals with osteoporosis, leading to high global mortality rates. This study aimed to analyze the association between body mass index (BMI) and postoperative mortality in patients who underwent surgery for hip fractures. A total of 680 patients treated at a single institution between January 2018 and December 2022 were included. Factors such as age, BMI, sex, Charlson Comorbidity Index (CCI), preoperative hemoglobin levels, American Society of Anesthesiologists score, anesthesia method, duration of surgery, and time from injury to surgery were assessed. Underweight status, male sex, higher CCI, and general anesthesia were significantly associated with 1-year and in-hospital mortality. Notably, underweight individuals exhibited a higher risk of mortality than normal-weight individuals, and female patients had lower mortality rates. This study underscores the importance of considering BMI, along with other demographic and clinical factors, in predicting postoperative mortality among patients with hip fractures, aiding the development of tailored management strategies to improve outcomes and reduce complications in this vulnerable patient population.

Reduction Mammoplasty in the Pediatric Population: An Analysis of Pediatric NSQIP Data From 2012 to 2019

Introduction: Reduction mammoplasty is becoming more commonly performed in the pediatric population yet the risk factors for complications have not been well-studied. The purpose of this study was to assess the relationship between preoperative patient characteristics and postoperative complications in a large population of pediatric patients undergoing reduction mammoplasty. Methods: Pediatric patients undergoing reduction mammoplasty were identified within the 2012 to 2019 National Surgical Quality Improvement Program database for cross-sectional study. The predictor variables were age, body mass index (BMI), diabetes, chronic steroid use, time under anesthesia, and operative time, and the primary outcome was a 30-day postoperative surgical site-related complication. Multivariate logistic regression was performed to identify a relationship between predictor variable and primary outcome. Results: A total of 1216 pediatric patients were identified with a mean age of 16.6 years and mean BMI of 30.8 kg/m2. The incidence of overall postoperative complications was 4.6%. Superficial surgical site infection (SSI) was the most common complication (29/1216; 2.4%). BMI was significantly associated with superficial SSI (odds ratio: 1.03, 95% confidence interval: 1.00-1.05, P = .02). Sixteen patients (1.32%) underwent a second operation, most commonly to address hematoma/seroma (7/16; 43.8%). Conclusion: In a large series of patients, pediatric reduction mammoplasty is a safe procedure with a low complication rate. BMI was significantly associated with the incidence of superficial SSIs with the most common cause for reoperation being a hematoma/seroma. This study can help guide the discussion between physicians and patients regarding potential risks associated with pediatric reduction mammoplasty.

Risk factors for anastomotic leakage after low anterior resection for obese patients with rectal cancer

PURPOSE

We aimed to analyze the risk factors for anastomotic leakage (AL) after low anterior resection (LAR) in obese patients (body mass index [BMI] ≥ 25 kg/m2) with rectal cancer.

METHODS

Data were collected from four hundred two obese patients who underwent LAR for rectal cancer in 51 institutions.

RESULTS

Forty-six (11.4%) patients had clinical AL. The median BMI (27 kg/m2) did not differ between the AL and non-AL groups. In the AL group, comorbid respiratory disease was more common (p = 0.025), and the median tumor size was larger (p = 0.002). The incidence of AL was 11.5% in the open surgery subgroup and 11.4% in the laparoscopic surgery subgroup. Among the patients who underwent open surgery, the AL group showed a male predominance (p = 0.04) in the univariate analysis, but it was not statistically significant in the multivariate analysis. Among the patients who underwent laparoscopic surgery, the AL group included a higher proportion of patients with comorbid respiratory disease (p = 0.003) and larger tumors (p = 0.007).

CONCLUSION

Comorbid respiratory disease and tumor size were risk factors for AL in obese patients with rectal cancer. Careful perioperative respiratory management and appropriate selection of surgical procedures are required for obese rectal cancer patients with respiratory diseases.

Impact of Obesity and Metabolic Syndrome on IBD Outcomes

PURPOSE OF REVIEW

The recent surge in inflammatory bowel disease (IBD) cases has paralleled a significant rise in obesity and metabolic comorbidities rates. In this article, we explore the potential influence of obesity and associated metabolic comorbidities on disease progression, complications, treatment response, surgical outcomes, health economics, and the potential impact of obesity treatment on the course of IBD.

FINDINGS

Contrary to visceral adiposity, obesity does not consistently result in an increased risk of IBD-related complications. Patients with IBD have a higher risk of acute arterial events, likely linked to systemic inflammation. Substantial evidence suggests that obesity has a negative impact on the response to IBD treatment, with this effect being most thoroughly studied in biologics and immunomodulators. The rates of overall complications and post-operative infections are higher in patients who are obese. There are limited but promising data regarding the impact of weight loss techniques, including exercise, medications, and bariatric interventions, on the outcomes in IBD. Both obesity and diabetes have adverse effects on the overall quality of life and place an increased financial burden on the IBD population. A growing body of evidence indicates a connection between obesity and associated metabolic comorbidities and negative outcomes in IBD, yet further efforts are required to fully understand this relationship.

Impact of spinal or epidural anaesthesia on perioperative outcomes in adult noncardiac surgery: a narrative review of recent evidence

Spinal and epidural anaesthesia and analgesia are important anaesthetic techniques, familiar to all anaesthetists and applied to patients undergoing a range of surgical procedures. Although the immediate effects of a well-conducted neuraxial technique on nociceptive and sympathetic pathways are readily observable in clinical practice, the impact of such techniques on patient-centred perioperative outcomes remains an area of uncertainty and active research. The aim of this review is to present a narrative synthesis of contemporary clinical science on this topic from the most recent 5-year period and summarise the foundational scholarship upon which this research was based. We searched electronic databases for primary research, secondary research, opinion pieces, and guidelines reporting the relationship between neuraxial procedures and standardised perioperative outcomes over the period 2018-2023. Returned citation lists were examined seeking additional studies to contextualise our narrative synthesis of results. Articles were retrieved encompassing the following outcome domains: patient comfort, renal, sepsis and infection, postoperative cancer, cardiovascular, and pulmonary and mortality outcomes. Convincing evidence of the beneficial effect of epidural analgesia on patient comfort after major open thoracoabdominal surgery outcomes was identified. Recent evidence of benefit in the prevention of pulmonary complications and mortality was identified. Despite mechanistic plausibility and supportive observational evidence, there is less certain experimental evidence to support a role for neuraxial techniques impacting on other outcome domains. Evidence of positive impact of neuraxial techniques is best established for the domains of patient comfort, pulmonary complications, and mortality, particularly in the setting of major open thoracoabdominal surgery. Recent evidence does not strongly support a significant impact of neuraxial techniques on cancer, renal, infection, or cardiovascular outcomes after noncardiac surgery in most patient groups.

Smokers Achieved Minimal Clinically Important Difference for Visual Analog Scale and American Shoulder and Elbow Surgeons Scores at a Lower Rate Than Nonsmokers Even When Repaired Supraspinatus Tendons Were Intact on Postoperative Magnetic Resonance Imaging

Purpose

To investigate the impact of smoking on clinical outcomes after repair of supraspinatus tendon in patients who had an intact repair found on postoperative magnetic resonance imaging.

Methods

Patients who received primary complete repair of supraspinatus tendon tear between 2014 and 2020 were retrospectively identified. Patients were excluded if a postoperative magnetic resonance imaging scan was not available or if the follow-up was less than 2 years. Visual analog score (VAS), American Shoulder and Elbow Surgeons (ASES) score, and active forward flexion were assessed at the 2-year follow-up. The percentage of patients acquiring minimal clinically important difference (MCID) was reported.

Results

One hundred primary supraspinatus tendon repairs were included. The healing rate was 77% in smokers and 90% in nonsmokers. Smoking was the independent predictor of a poorer 2-year VAS (P < .001) and ASES (P < .001) scores. Significant improvement in clinical outcomes was observed between preoperation and the 2-year follow-up, regardless of the integrity of the repair or smoking status (P < .001). When the repaired tendon was intact, nonsmokers had a greater chance of achieving MCID in 2-year VAS and ASES scores than smokers. Ninety-nine percent of nonsmokers, compared with 82% of smokers, achieved MCID in VAS at the 2-year follow-up (P = .023). The corresponding figures for ASES were 98% and 71%, respectively (P = .004).

Conclusions

In this study, smoking was associated with poorer clinical outcomes, including a greater 2-year VAS pain score and a lower 2-year ASES score, when compared with nonsmokers, even in cases in which there was no full-thickness retear of the repaired supraspinatus tendon.

Level of Evidence

Level III, retrospective cohort study.

Oxygenated Hydrogel Promotes Re-Epithelialization and Reduces Inflammation in a Perturbed Wound Model in Rat

Chronic wounds can take months or even years to heal and require proper medical intervention. Normal wound healing processes require adequate oxygen supply. Accordingly, destroyed or inefficient vasculature leads to insufficient delivery to peripheral tissues and impair healing. Oxygen is critical for vital processes such as proliferation, collagen synthesis and antibacterial defense. Hyperbaric oxygen therapy (HBOT) is commonly used to accelerate healing however, this can be costly and requires specialized training and equipment. Efforts have turned to the development of topical oxygen delivery systems. Oxysolutions has developed oxygenated gels (P407, P407/P188, nanocellulose based gel (NCG)) with high levels of dissolved oxygen. This study aims to evaluate the efficacy of these newly developed oxygenated products by assessing their impact on healing rates in a rat perturbed wound model. Here, P407/P188 oxygenated gels demonstrated greater re-epithelialization distances compared to its controls at Day 3. In addition, all oxygenated gels had a higher proportion of wounds with complete wound closure. All three oxygenated gels also minimized further escalation in inflammation from Day 3 to Day 10. This highlights the potential of this newly-developed oxygenated gels as an alternative to existing oxygen therapies.

Associations between the intraoperative fraction of inspired intraoperative oxygen administration and days alive and out of hospital after surgery

Background

There is limited knowledge about the effect of liberal intraoperative oxygen on non-infectious complications and overall recovery from surgery.

Methods

In this retrospective cohort study, we investigated associations between mean intraoperative fraction of inspired oxygen (FiO2), and outcome in adults undergoing elective surgery lasting more than 2 h at a large metropolitan New Zealand hospital from 2012 to 2020. Patients were divided into low, medium, and high oxygen groups (FiO2 ≤ 0.4, 0.41-0.59, ≥0.6). The primary outcome was days alive and out of hospital at 90 days (DAOH90). The secondary outcomes were post-operative complications and admission to the ICU.

Results

We identified 15,449 patients who met the inclusion criteria. There was no association between FiO2 and DAOH90 when high FiO2 was analysed according to three groups. Using high FiO2 as the reference group there was an adjusted mean (95% confidence interval [CI]) difference of 0.09 (-0.06 to 0.25) days (P = 0.25) and 0.28 (-0.05 to 0.62) days (P = 0.2) in the intermediate and low oxygen groups, respectively. Low FiO2 was associated with increased surgical site infection: the adjusted odds ratio (OR) for low compared with high FiO2 was 1.53 (95% CI 1.12-2.10). Increasing FiO2 was associated with respiratory complications: the adjusted OR associated with each 10% point increase in FiO2 was 1.17 (95% CI 1.08-1.26) and the incidence of being admitted to an ICU had an adjusted OR of 1.1 (95% CI 1.03-1.18).

Conclusions

We found potential benefits, and risks, associated with liberal intraoperative oxygen administration indicating that randomised controlled trials are warranted.

Impact of hyperoxia on the gut during critical illnesses

Molecular oxygen is typically delivered to patients via oxygen inhalation or extracorporeal membrane oxygenation (ECMO), potentially resulting in systemic hyperoxia from liberal oxygen inhalation or localized hyperoxia in the lower body from peripheral venoarterial (VA) ECMO. Consequently, this exposes the gastrointestinal tract to excessive oxygen levels. Hyperoxia can trigger organ damage due to the overproduction of reactive oxygen species and is associated with increased mortality. The gut and gut microbiome play pivotal roles in critical illnesses and even small variations in oxygen levels can have a dramatic influence on the physiology and ecology of gut microbes. Here, we reviewed the emerging preclinical evidence which highlights how excessive inhaled oxygen can provoke diffuse villous damage, barrier dysfunction in the gut, and gut dysbiosis. The hallmark of this dysbiosis includes the expansion of oxygen-tolerant pathogens (e.g., Enterobacteriaceae) and the depletion of beneficial oxygen-intolerant microbes (e.g., Muribaculaceae). Furthermore, we discussed potential impact of oxygen on the gut in various underlying critical illnesses involving inspiratory oxygen and peripheral VA-ECMO. Currently, the available findings in this area are somewhat controversial, and a consensus has not yet to be reached. It appears that targeting near-physiological oxygenation levels may offer a means to avoid hyperoxia-induced gut injury and hypoxia-induced mesenteric ischemia. However, the optimal oxygenation target may vary depending on special clinical conditions, including acute hypoxia in adults and neonates, as well as particular patients undergoing gastrointestinal surgery or VA-ECMO support. Last, we outlined the current challenges and the need for future studies in this area. Insights into this vital ongoing research can assist clinicians in optimizing oxygenation for critically ill patients.

Effect of wound infiltration of dexmedetomidine in lumbar spine surgery on postoperative wound pain: A meta-analysis

In a meta-study, we evaluated the effectiveness and security of the combination of topical anaesthetic and dexmedetomidine in the treatment of postoperative pain in patients with lumbar disease. Four databases were systematically searched for possible related articles. Only English-language research was taken into account on the Internet. Furthermore, we only took into account the studies that were published prior to 2023. Only those that fulfilled the eligibility criteria were considered: (1) in adults who were about to undergo spine operation, (2) dexmedetomidine combined with local anaesthesia, (3) Visual Analog Scale scores at 4 and 24 h after the event and (4) this was a randomized or nonrandomized, controlled study. The meta-analysis was carried out with Revman 5.3 software. A ROBINS-I-based instrument was used to evaluate controlled studies. All trials were synthesized by computing the end results with either a fixed or a random effect model, which was dependent on statistical diversity. Five trials showed a marked reduction in wound pain at 4 h after the operation in patients who were treated with dexmedetomidine for lumbar spinal surgery (MD, -0.81; 95% CI, -1.24, -0.35; p = 0.0005). In the case of lumbar spinal operations, the addition of dexmedetomidine to the postoperative treatment resulted in a marked reduction in the pain at 24 h post-operation (MD, -0.64; 95% CI, -0.79, -0.48; p < 0.0001). The quality of the data we evaluated was 'moderate' to 'good'; thus, we have limited confidence in the impact estimation, and the actual impact might be significantly different from what we had expected. Additional studies should concentrate on practices that are well known to cause severe postoperative pain, especially for cases where the improvement of pain management may lead to substantial clinical benefits in terms of reduction of morbidity or cost-effectiveness in terms of quicker healing and release.

Impact of Intra-Operative Shock and Resuscitation on Surgical Site Infections After Trauma Laparotomy

Background: Patients undergoing trauma laparotomy experience high rates of surgical site infection (SSI). Although intra-operative shock is a likely contributor to SSI risk, little is known about the relation between shock, intra-operative restoration of physiologic normalcy, and SSI development. Patients and Methods: A retrospective review of trauma patients who underwent emergent definitive laparotomy was performed. Using shock index and base excess at the beginning and end of laparotomy, patients were classified as normal, persistent shock, resuscitated, or new shock. Univariable and multivariable analyses were performed to identify predictors of organ/space SSI, superficial/deep SSI, and any SSI. Results: Of 1,191 included patients, 600 (50%) were categorized as no shock, 248 (21%) as resuscitated, 109 (9%) as new shock, and 236 (20%) as persistent shock, with incidence of any SSI as 51 (9%), 28 (11%), 26 (24%), and 32 (14%), respectively. These rates were similar in organ/space and superficial/deep SSIs. On multivariable analysis, resuscitated, new shock, and persistent shock were associated with increased odds of organ/space SSI (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.3-3.5; p < 0.001) and any SSI (OR, 2.0; 95% CI, 1.4-3.2; p < 0.001), but no increased risk of superficial/deep SSI (OR, 1.4; 95% CI, 0.8-2.6; p = 0.331). Conclusions: Although the trajectory of physiologic status influenced SSI, the presence of shock at any time during trauma laparotomy, regardless of restoration of physiologic normalcy, was associated with increased odds of SSI. Further investigation is warranted to determine the relation between peri-operative shock and SSI in trauma patients.

Low-Cost Wound Healing Protocol Reduces Infection and Reoperation Rates After Cranioplasty: A Retrospective Cohort Study

BACKGROUND AND OBJECTIVES

Cranioplasty infections are a common and expensive problem associated with significant morbidity. Our objective was to determine whether a wound healing protocol after cranioplasty reduced the rate of infections and to determine the value of this intervention.

METHODS

This is a single-institution retrospective chart review of 2 cohorts of cranioplasty patients over 12 years. The wound healing protocol, consisting of vitamin and mineral supplementation, fluid supplementation, and oxygen support, was instituted for all patients aged older than 15 years undergoing cranioplasty. We retrospectively reviewed the charts of all patients over the study period and compared outcomes before and after protocol institution. Outcomes included surgical site infection, return to operating room within 30 days, and cranioplasty explant. Cost data were collected from the electronic medical record. We included 291 cranioplasties performed before the wound healing protocol and 68 postprotocol.

RESULTS

Baseline demographics and comorbidities were comparable between preprotocol and postprotocol groups. Odds of takeback to operating room within 30 days were the same before and after the wound healing protocol (odds ratio [OR] 2.21 [95% CI 0.76-6.47], P = .145). Odds of clinical concern for surgical site infection were significantly higher in the preprotocol group (OR 5.21 [95% CI 1.22-22.17], P = .025). Risk of washout was higher in the preprotocol group (HR 2.86 [95% CI 1.08-7.58], P = .035). Probability of cranioplasty flap explant was also significantly higher in the preprotocol group (OR 4.70 [95% CI 1.10-20.05], P = .036). The number needed to treat to prevent 1 cranioplasty infection was 24.

CONCLUSION

A low-cost wound healing protocol was associated with reduced rate of infections after cranioplasty with concomitant reduction in reoperations for washout, saving the health care system more than $50,000 per 24 patients. Prospective study is warranted.

The effect of high perioperative inspiratory oxygen fraction for abdominal surgery on surgical site infection: a systematic review and meta-analysis

Guidelines from the World Health Organization strongly recommend the use of a high fraction of inspired oxygen (FiO2) in adult patients undergoing general anesthesia to reduce surgical site infection (SSI). However, previous meta-analyses reported inconsistent results. We aimed to address this controversy by focusing specifically on abdominal surgery with relatively high risk of SSI. Medline, EMBASE, and Cochrane CENTRAL databases were searched. Randomized trials of abdominal surgery comparing high to low perioperative FiO2 were included, given that the incidence of SSI was reported as an outcome. Meta-analyses of risk ratios (RR) were performed using a fixed effects model. Subgroup analysis and meta-regression were employed to explore sources of heterogeneity. We included 27 trials involving 15977 patients. The use of high FiO2 significantly reduced the incidence of SSI (n = 27, risk ratio (RR): 0.87; 95% confidence interval (CI): 0.79, 0.95; I2 = 49%, Z = 3.05). Trial sequential analysis (TSA) revealed that z-curve crossed the trial sequential boundary and data are sufficient. This finding held true for the subgroup of emergency operations (n = 2, RR: 0.54; 95% CI: 0.35, 0.84; I2 = 0%, Z = 2.75), procedures using air as carrier gas (n = 9, RR: 0.79; 95% CI: 0.69, 0.91; I2 = 60%, Z = 3.26), and when a high level of FiO2 was maintained for a postoperative 6 h or more (n = 9, RR: 0.68; 95% CI: 0.56, 0.83; I2 = 46%, Z = 3.83). Meta-regression revealed no significant interaction between SSI with any covariates including age, sex, body-mass index, diabetes mellitus, duration of surgery, and smoking. Quality of evidence was assessed to be moderate to very low. Our pooled analysis revealed that the application of high FiO2 reduced the incidence of SSI after abdominal operations. Although TSA demonstrated sufficient data and cumulative analysis crossed the TSA boundary, our results should be interpreted cautiously given the low quality of evidence.Registration: https://www.crd.york.ac.uk/prospero (CRD42022369212) on October 2022.

A meta-analysis of the effect of different body mass index on surgical wound infection after colorectal surgery

We conducted a meta-analysis to assess the effect of different body mass index on surgical wound infection after colorectal surgery. A systematic literature search up to November 2022 was performed and 2349 related studies were evaluated. The chosen studies comprised 15 595 colorectal surgery subjects participated in the selected studies' baseline trials; 4390 of them were obese according to the selected body mass index cut-off used to measure obesity in the selected studies, while 11 205 were nonobese. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of different body mass index on wound infection after colorectal surgery by the dichotomous methods with a random or fixed effect model. The body mass index ≥30 kg/m2 resulted in significantly higher surgical wound infection after colorectal surgery (OR, 1.76; 95% CI, 1.46-2.11, P < .001) compared with the body mass index <30 kg/m2 . The body mass index ≥25 kg/m2 resulted in significantly higher surgical wound infection after colorectal surgery (OR, 1.64; 95% CI, 1.40-1.92, P < .001) compared with the body mass index <25 kg/m2 . The subjects with higher body mass index had a significantly higher surgical wound infection after colorectal surgery compared with the subjects with normal body mass index.

Short-term outcomes between robot-assisted and open pancreaticoduodenectomy in patients with high body mass index: A propensity score matched study

BACKGROUND

High body mass index was considered as a risk factor for minimally invasive surgery. The short-term outcomes of robot-assisted pancreaticoduodenectomy (RPD) remain controversial. This study aims to investigate the feasibility and advantage of RPD in patients with high body mass index compared to open pancreaticoduodenectomy (OPD).

METHODS

Clinical data of 304 patients who underwent pancreaticoduodenectomy from January 2016 to December 2019 in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine was collected. Patients with BMI >25 kg/m2 were included and divided into RPD and OPD group. After PSM at a 1:1 ratio, 75 patients of OPD and 75 patients of RPD were recorded and analyzed.

RESULTS

The RPD group showed advantages in the estimated blood loss (EBL) (323.3 mL vs. 480.7 mL, p = 0.010), the postoperative abdominal infection rate (24% vs. 44%, p = 0.010), the incidence of Clavien-Dindo III-V complications (14.7% vs. 28.0%, p = 0.042) over OPD group.

CONCLUSION

RPD shows advantages in less EBL, lower incidence rate of Clavien-Dindo III-V complications over OPD in overweight and obese patients. RPD was confirmed as a safe and feasible surgical approach for overweight or obsess patients.

Impact of obesity on patients undergoing surgery for rectal cancer in Australia and New Zealand

PURPOSE

Patients with obesity undergoing rectal cancer surgery may have an increased risk of developing complications, though evidence is inconclusive. The aim of this study was to determine the direct impact of obesity on postoperative outcomes using data from a large clinical registry.

METHOD

The Binational Colorectal Cancer Audit registry was used to identify patients who underwent rectal cancer surgery in Australia and New Zealand from 2007-2021. Primary outcomes were inpatient surgical and medical complications. Logistic regression models were developed to describe the association between body-mass index (BMI) and outcomes.

RESULTS

Among 3,708 patients (median age 66 years [IQR 56.75-75], 65.0% male), 2.0% had a BMI < 18.5 kg/m2, 35.4% had a BMI of 18.5-24.9 kg/m2, 37.6% had a BMI of 25.0-29.9 kg/m2, 16.7% had a BMI of 30.0-34.9 kg/m2, and 8.2% had a BMI ≥ 35.0 kg/m2. Surgical complications occurred in 27.7% of patients with a BMI of 18.5-24.9 kg/m2, 26.6% of patients with a BMI of 25.0-29.9 kg/m2 (OR 0.91, 95% CI 0.76-1.10), 28.5% with a BMI of 30.0-34.9 kg/m2 (OR 0.96, 95% CI 0.76-1.21), and 33.2% with a BMI ≥ 35.0 kg/m2 (OR 1.27, 95% CI 0.94-1.71). Modelling BMI as a continuous variable confirmed a J-shaped relationship. The association between BMI and medical complications was more linear.

CONCLUSION

Risk of postoperative complications is increased in patients with obesity undergoing rectal cancer surgery.

An Assessment of the Relationship Between BMI and Children Undergoing Surgical Procedures: A Retrospective Study

Background: While multiple studies have documented that obesity increases the risk of operative complications among adults, little data exist on how obesity impacts surgical outcomes among children. We aimed to determine if children with obesity have different postoperative outcomes than their peers. Methods: A retrospective chart review was conducted of 875 patients aged between 2 and 18 years who underwent surgery during 2018. Patients were stratified, based on BMI percentile for age, as having less than healthy weight (<5th percentile), healthy weight (5th-84th percentile), excess weight (85th-94th percentile), or obesity (≥95th percentile). Demographic information and data on medical comorbidities and postoperative complications were collected. All analyses were conducted using chi-square or Kruskal-Wallis testing. Results: Eighty-two patients were excluded due to lack of BMI data and 56 were excluded as they had below healthy weight. Of the remaining 737 patients, 475 (64.4%) had healthy weight, 124 (16.8%) had excess weight, and 138 (18.70%) had obesity. Children with obesity had more tonsillectomy/adenoidectomy (p < 0.01) and vascular access (p = 0.04) procedures compared with peers. Additionally, patients with obesity were more likely to have a pre-existing history of liver disease (p < 0.01) and more frequently developed postoperative wound dehiscence (p < 0.01). No other complications occurred more frequently among children with obesity. Conclusions: Children with obesity required more tonsillectomy/adenoidectomy and vascular access procedures. Wound dehiscence was the only complication that was associated with obesity. This suggests that children with obesity are not inherently more prone to experience surgical complications and therefore elective procedures should likely not be deferred until preoperative weight loss is achieved.

Characteristics and Outcomes of Patients Undergoing Surgical Management of Hidradenitis Suppurativa: An ACS-NSQIP Data Analysis

Objective: Hidradenitis suppurativa (HS) is a painful inflammatory skin disease. Management is largely medical, with surgery reserved for severe refractory cases. In this study, we sought to conduct a retrospective analysis of a multi-institutional surgical database to investigate the surgical management of patients with HS and identify trends in the postoperative outcomes. Approach: The 2011-2019 American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was reviewed to identify patients who underwent surgery for management of HS. Postoperative outcomes were assessed, including surgical and medical complications, length of hospital stay, reoperation, readmission, and nonhome discharge. This article was reported according to the STROBE criteria. Results: We identified 1,030 patients, of which 62% were female and 50% were black. The most common comorbidity was obesity (61%). Surgery was mainly performed by general surgeons (62%) and plastic surgeons (31%). Complications were overall low, with readmission being the most common (7.1%, unplanned 6.0%), followed by reoperation (5.8%). The most common surgical complication was superficial incisional infection (5.1%) and most common medical complication was sepsis (3.8%). Obesity is seen to affect surgical complication rates, with patients with obesity having higher rates of dehiscence (obese: 3.1% and nonobese: 1.0%; p = 0.03) but lower rates of organ space infection (obese: 0.5% and nonobese: 2.0%; p = 0.03) and transfusion (obese: 2.5% and nonobese: 5.2%; p = 0.04). A focus on complications in patients undergoing flap reconstruction (n = 293; 23%), identified higher rates of surgical complications, with superficial incisional infection being the most common (flap reconstruction: 7.5% and incision and drainage, debridement, skin graft: 4.1%; p = 0.04). Innovation: The surgical management of HS is analyzed at the national level, with postoperative complications seen to depend on race and obesity-status. Conclusions: Surgical management for HS is associated with low postoperative complications, making surgery a viable treatment option for this debilitating disease.

Hyperbaric Oxygen Therapy Reduces Oxidative Stress and Inflammation, and Increases Growth Factors Favouring the Healing Process of Diabetic Wounds

Hyperbaric oxygen therapy (HBOT) is the clinical application of oxygen at pressures higher than atmospheric pressure. HBOT has been effectively used to manage diverse clinical pathologies, such as non-healing diabetic ulcers. The aim of the present study was to analyse the effects of HBOT on the plasma oxidative and inflammation biomarkers and growth factors in patients with chronic diabetic wounds. The participants received 20 HBOT sessions (five sessions/week), and blood samples were obtained at sessions 1, 5 and 20, before and 2 h after the HBOT. An additional (control) blood sample was collected 28 days after wound recovery. No significant differences were evident in haematological parameters, whereas the biochemical parameters progressively decreased, which was significant for creatine phosphokinase (CPK) and aspartate aminotransferase (AST). The pro-inflammatory mediators, tumour necrosis factor alpha (TNF-α) and interleukin 1β (IL-1β), progressively decreased throughout the treatments. Biomarkers of oxidative stress--plasma protein levels of catalase, extracellular superoxide dismutase, myeloperoxidase, xanthine oxidase, malondialdehyde (MDA) levels and protein carbonyls--were reduced in accordance with wound healing. Plasma levels of growth factors--platelet-derived growth factor (PDFG), transforming growth factor β (TGF-β) and hypoxia-inducible factor 1-alpha (HIF-1α)-- were increased as a consequence of HBOT and reduced 28 days after complete wound healing, whereas matrix metallopeptidase 9 (MMP9) progressively decreased with the HBOT. In conclusion, HBOT reduced oxidative and pro-inflammatory mediators, and may participate in activating healing, angiogenesis and vascular tone regulation by increasing the release of growth factors.

The effect of prophylactic mesh implantation on the development of incisional hernias in patients with elevated BMI: a systematic review and meta-analysis

BACKGROUND

Incisional hernia is a common complication after midline laparotomy. In certain risk profiles incidences can reach up to 70%. Large RCTs showed a positive effect of prophylactic mesh reinforcement (PMR) in high-risk populations.

OBJECTIVES

The aim was to evaluate the effect of prophylactic mesh reinforcement on incisional hernia reduction in obese patients after midline laparotomies.

METHODS

Following the PRISMA guidelines, a systematic literature search in Medline, Web of Science and CENTRAL was conducted. RCTs investigating PMR in patients with a BMI ≥ 27 reporting incisional hernia as primary outcome were included. Study quality was assessed using the Cochrane risk-of-bias tool and certainty of evidence was rated according to the GRADE Working Group grading of evidence. A random-effects model was used for the meta-analysis. Secondary outcomes included postoperative complications.

RESULTS

Out of 2298 articles found by a systematic literature search, five RCTs with 1136 patients were included. There was no significant difference in the incidence of incisional hernia when comparing PMR with primary suture (odds ratio (OR) 0.59, 95% CI 0.34-1.01, p = 0.06, GRADE: low). Meta-analyses of seroma formation (OR 1.62, 95% CI 0.72-3.65; p = 0.24, GRADE: low) and surgical site infections (OR 1.52, 95% CI 0.72-3.22, p = 0.28, GRADE: moderate) showed no significant differences as well as subgroup analyses for BMI ≥ 40 and length of stay.

CONCLUSIONS

We did not observe a significant reduction of the incidence of incisional hernia with prophylactic mesh reinforcement used in patients with elevated BMI. These results stand in contrast to the current recommendation for hernia prevention in obese patients.

Peri-anesthetic hypothermia in rodents: A factor to consider for accurate and reproducible outcomes in orthopedic device-related infection studies

Orthopedic device-related infection (ODRI) preclinical models are widely used in translational research. Most ODRI models require induction of general anesthesia, which frequently results in hypothermia in rodents. This study aimed to evaluate the impact of peri-anesthetic hypothermia in rodents on outcomes in preclinical ODRI studies. A retrospective analysis of all rodents that underwent surgery under general anesthesia to induce an ODRI model with inoculation of Staphylococcus epidermidis between 2016 and 2020 was conducted. A one-way multivariate analysis of covariance (one-way MANCOVA) was used to determine the fixed effect of peri-anesthetic hypothermia (hypothermic defined as rectal temperature <35°C) on the combined harvested tissue and implant colony-forming unit (CFU) counts, and having controlled for the study groups including treatments received, duration of surgery and anesthesia, and study period. The results showed a significant effect of peri-anesthetic hypothermia on the post-mortem combined CFU counts from the harvested tissue and implant(s) (p = 0.01) when comparing normo- versus hypothermic rodents. Using Wilks' Λ as a criterion to determine the contribution of independent variables to the model, peri-anesthetic hypothermia was the most significant, though still a weak predictor, of increased harvested CFU counts. Altogether, the data corroborate the concept that bacterial colonization is affected by abnormal body temperature during general anesthesia at the time of bacterial inoculation in rodents, which needs to be taken into consideration to decrease infection data variability and improve experimental reproducibility.

Postoperative Supplemental Oxygen in Liver Transplantation (PSOLT) does not reduce the rate of infections: results of a randomized controlled trial

BACKGROUND

Despite inconsistent evidence, international guidelines underline the importance of perioperative hyperoxygenation in prevention of postoperative infections. Further, data on safety and efficacy of this method in liver transplant setting are lacking. The aim was to evaluate efficacy and safety of postoperative hyperoxygenation in prophylaxis of infections after liver transplantation.

METHODS

In this randomized controlled trial, patients undergoing liver transplantation were randomly assigned to either 28% or 80% fraction of inspired oxygen (FiO2) for 6 postoperative hours. Infections occurring during 30-day post-transplant period were the primary outcome measure. Secondary outcome measures included 90-day mortality, 90-day severe morbidity, 30-day pulmonary complications, durations of hospital and intensive care unit stay, and 5-day postoperative bilirubin concentration, alanine and aspartate transaminase activity, and international normalized ratio (INR) (clinicatrials.gov NCT02857855).

RESULTS

A total of 193 patients were included and randomized to 28% (n = 99) and 80% (n = 94) FiO2. With similar patient, operative, and donor characteristics in both groups, infections occurred in 34.0% (32/94) of patients assigned to 80% FiO2 as compared to 23.2% (23/99) of patients assigned to 28% FiO2 (p = 0.112). Patients randomized to 80% FiO2 more frequently developed severe complications (p = 0.035), stayed longer in the intensive care unit (p = 0.033), and had higher bilirubin concentration over first 5 post-transplant days (p = 0.043). No significant differences were found regarding mortality, duration of hospital stay, pulmonary complications, and 5-day aspartate and alanine transaminase activity and INR.

CONCLUSIONS

Postoperative hyperoxygenation should not be used for prophylaxis of infections after liver transplantation due to the lack of efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02857855. Registered 7 July 2016.

Topical oxygen therapy in acute traumatic musculoskeletal wounds of the foot and ankle

OBJECTIVE

To quantify the reduction in wound size and change in wound quality following low-cost topical oxygen therapy (TOT) in patients with acute traumatic musculoskeletal wounds of the foot and ankle.

METHOD

This prospective interventional study included patients with acute traumatic musculoskeletal wounds of the foot and ankle of <3 weeks' duration after they had undergone debridement and required subsequent wound coverage. A sterile C-Arm cover was used to cover the wound and 100% oxygen was administered at 1 atm, at a rate of 10l/min for 90 minutes on each of four consecutive days, through a suction catheter connected to an oxygen cylinder. The cycle was repeated after a three-day break. Wound surface area (by plotting on graph paper) and wound quality (by modified wound infection checklist score and swabs for culture and Gram staining) were assessed before and after TOT application.

RESULTS

The study cohort included 20 patients ≥18 years of age. There was a statistically significant (p<0.001) reduction in mean wound surface area from 79.3cm² at baseline to 69.6cm² after two cycles of TOT. The mean modified wound infection checklist score was 13.6 and 0.8, respectively, before and after two cycles of TOT, suggesting statistically significant improvement (p=0.02) in wound quality. All patients showed no growth in their wound culture after TOT.

CONCLUSION

TOT appears to be a promising and cost-effective alternative in the management of traumatic wounds. However, future studies with larger sample sizes and control groups for comparison are needed to establish the benefit of TOT in acute traumatic musculoskeletal wounds.

Predictors of surgical site infection following reconstructive flap surgery: A multi-institutional analysis of 37,177 patients

Purpose

Rates of surgical site infection (SSI) following reconstructive flap surgeries (RFS) vary according to flap recipient site, potentially leading to flap failure. This is the largest study to determine predictors of SSI following RFS across recipient sites.

Methods

The National Surgical Quality Improvement Program database was queried for patients undergoing any flap procedure from years 2005 to 2020. RFS involving grafts, skin flaps, or flaps with unknown recipient site were excluded. Patients were stratified according to recipient site: breast, trunk, head and neck (H&N), upper and lower extremities (UE&LE). The primary outcome was the incidence of SSI within 30 days following surgery. Descriptive statistics were calculated. Bivariate analysis and multivariate logistic regression were performed to determine predictors of SSI following RFS.

Results

37,177 patients underwent RFS, of whom 7.5% (n = 2,776) developed SSI. A significantly greater proportion of patients who underwent LE (n = 318, 10.7%) and trunk (n = 1,091, 10.4%) reconstruction developed SSI compared to those who underwent breast (n = 1,201, 6.3%), UE (n = 32, 4.4%), and H&N (n = 100, 4.2%) reconstruction (p < .001). Longer operating times were significant predictors of SSI following RFS across all sites. The strongest predictors of SSI were presence of open wound following trunk and H&N reconstruction [adjusted odds ratio (aOR) 95% confidence interval (CI) 1.82 (1.57-2.11) and 1.75 (1.57-1.95)], disseminated cancer following LE reconstruction [aOR (CI) 3.58 (2.324-5.53)], and history of cardiovascular accident or stroke following breast reconstruction [aOR (CI) 16.97 (2.72-105.82)].

Conclusion

Longer operating time was a significant predictor of SSI regardless of reconstruction site. Reducing operating times through proper surgical planning might help mitigate the risk of SSI following RFS. Our findings should be used to guide patient selection, counseling, and surgical planning prior to RFS.

Optimization of the target strategy of perioperative infusion therapy based on monitoring data of central hemodynamics in order to prevent complications

Enhanced Recovery After Surgery (ERAS) protocols are increasingly used in the perioperative period around the world. The concept of goal-directed fluid therapy (GDT) is a key element of the ERAS protocols. Inadequate perioperative infusion therapy can lead to a number of complications, including the development of an infectious process, namely surgical site infections, pneumonia, urinary tract infections. Optimal infusion therapy is difficult to achieve with standard parameters (e.g., heart rate, blood pressure, central venous pressure), so there are various methods of monitoring central hemodynamics - from invasive, minimally invasive to non-invasive. The latter are increasingly used in clinical practice. The current evidence base shows that perioperative management, specifically the use of GDT guided by real-time, continuous hemodynamic monitoring, helps clinicians maintain a patient's optimal fluid balance. The manuscript presents the analytical data, which describe the benefits and basic principles of perioperative targeted infusion therapy based on central hemodynamic parameters to reduce the risk of complications.

Intraoperative angiography imaging correlates with wound complications following soft tissue sarcoma resection

For soft tissue sarcoma patients receiving preoperative radiation therapy, wound complications are common and potentially devastating. The purpose of this study was to assess the feasibility of intraoperative indocyanine green fluorescent angiography (ICGA) as a predictor of wound complications in these patients. A consecutive series of patients with soft tissue sarcoma of the extremities or pelvis who received neoadjuvant radiation and a subsequent radical resection received intraoperative ICGA with the SPY PHI device (Stryker Inc.) at the time of closure. Retrospective analysis of fluorescence signal along multiple points of the wound length was performed and quantified. The primary endpoint was wound complication, defined as delayed wound healing or wound dehiscence, within 3 months of surgery. Fourteen patients with preoperative irradiated soft tissue sarcoma were consecutively imaged. There were six patients with wound complications classified as "aseptic" in five cases. Using the ICGA, blinded surgeons correctly predicted wound complications in 75% of cases. During the inflow phase, a mean ratio of normal of 0.62 maximized the area under the curve (AUC = 0.90) for predicting wound complications with a sensitivity of 100% and specificity of 77.4%. During the peak phase, a mean ratio of normal of 0.55 maximized the AUC (0.95) for predicting wound complications with a sensitivity of 88.9% and a specificity of 100%. Intraoperative use of ICGA may help to predict wound complications in patients undergoing resection of preoperatively irradiated soft tissue sarcomas of the extremities and pelvis.

Correlation between Bacterial Wound Colonization and Skin-Graft Loss in Burn Patients

Loss of skin grafts can be a dangerous complication during the early postoperative course of patients with extensive burns. A major risk factor for impaired healing of grafts is local wound infection due to bacterial colonization. Burn wounds are particularly prone to bacterial colonization. In this retrospective cohort study, we analyzed correlations between bacteria isolates from burn wounds and loss of skin grafts after surgical treatment. A cohort of patients with burn wounds who received split-skin grafts for wound coverage was divided into groups with and without loss of skin grafts. Demographics, comorbidities, trauma characteristics and bacterial isolates from wound cultures were reviewed and compared. Bacterial colonization isolated from burn wounds upon hospital admission was found to be a significant predictor of skin-graft loss. Additionally, an Abbreviated Burn Severity Index greater 6 predicted graft loss. When comparing bacterial swab results from admission with isolates from revision surgery after graft loss, causative pathogens were found to have changed.

Hyperoxia Reprogrammes Microvascular Endothelial Cell Response to Hypoxia in an Organ-Specific Manner

Organ function relies on microvascular networks to maintain homeostatic equilibrium, which varies widely in different organs and during different physiological challenges. The endothelium role in this critical process can only be evaluated in physiologically relevant contexts. Comparing the responses to oxygen flux in primary murine microvascular EC (MVEC) obtained from brain and lung tissue reveals that supra-physiological oxygen tensions can compromise MVEC viability. Brain MVEC lose mitochondrial activity and undergo significant alterations in electron transport chain (ETC) composition when cultured under standard, non-physiological atmospheric oxygen levels. While glycolytic capacity of both lung and brain MVEC are unchanged by environmental oxygen, the ability to trigger a metabolic shift when oxygen levels drop is greatly compromised following exposure to hyperoxia. This is particularly striking in MVEC from the brain. This work demonstrates that the unique metabolism and function of organ-specific MVEC (1) can be reprogrammed by external oxygen, (2) that this reprogramming can compromise MVEC survival and, importantly, (3) that ex vivo modelling of endothelial function is significantly affected by culture conditions. It further demonstrates that physiological, metabolic and functional studies performed in non-physiological environments do not represent cell function in situ, and this has serious implications in the interpretation of cell-based pre-clinical models.

Prevention of Orthopedic Prosthetic Infections Using Evidence-Based Surgical Site Infection Care Bundles: A Narrative Review

Background: The number of primary/revision total joint replacements (TJR) are expected to increase substantially with an aging population and increasing prevalence of comorbid conditions. The 30-day re-admission rate, in all orthopedic specialties, is 5.4% (range, 4.8%-6.0%). A recent publication has documented that the surgical site infection (SSI) infection rate associated with revision total knee (rTKR, 15.6%) and revision total hip (rTHR, 8.6%) arthroplasties are four to seven times the rate of the primary procedures (2.1%-2.2%). These orthopedic infections prolong hospital stays, double re-admissions, and increase healthcare costs by a factor of 300%. Methods: A search of PubMed/MEDLINE, EMBASE and the Cochrane Library publications, which reported the infection risk after TKR and THR, was undertaken (January 1, 1995 to December 31, 2021). The search also included documentation of evidence-based practices that lead to improved post-operative outcomes. Results: The evidence-based approach to reducing the risk of SSI was grouped into pre-operative, peri-operative, and post-operative periods. Surgical care bundles have existed within other surgical disciplines for more than 20 years, although their use is relatively new in peri-operative orthopedic surgical care. Pre-admission chlorhexidine gluconate (CHG) showers/cleansing, staphylococcal decolonization, maintenance of normothermia, wound irrigation, antimicrobial suture wound closure, and post-operative wound care has been shown to improve clinical outcome in randomized controlled studies and meta-analyses. Conclusions: Evidence-based infection prevention care bundles have improved clinical outcomes in all surgical disciplines. The significant post-operative morbidity, mortality, and healthcare cost, associated with SSIs after TJR can be reduced by introduction of evidence-based pre-operative, intra-operative, and post-operative interventions.

Effect of Supplemental Perioperative Oxygen on SSI Among Adults with Lower-Extremity Fractures at Increased Risk for Infection: A Randomized Clinical Trial

BACKGROUND

Supplemental perioperative oxygen is a low-cost intervention theorized to reduce the risk of surgical site infections, but its effect among patients undergoing surgery for a tibial plateau, tibial pilon, or calcaneal fracture is unknown. We aimed to determine the effectiveness of a high fraction of inspired oxygen (FiO 2 , 80%) versus low FiO 2 (30%) in reducing surgical site infections in these patients.

METHODS

A randomized controlled trial was conducted at 29 U.S. trauma centers. We enrolled 1,231 patients who were 18 to 80 years of age and had a tibial plateau, tibial pilon, or calcaneal fracture and were thought to be at elevated risk for infection based on their injury characteristics. Patients were randomized to receive 80% FiO 2 (treatment group) or 30% FiO 2 (control group) in the operating room and for up to 2 hours in the recovery room. The primary outcome was a composite of either deep surgical site infection (treated with surgery) or superficial surgical site infection (treated with antibiotics alone) within 182 days following definitive fixation. Secondary outcomes included these surgical site infections at 90 and 365 days after surgery.

RESULTS

The modified intention-to-treat analysis included 1,136 patients with 94% of expected follow-up through 182 days. Surgical site infection occurred in 40 (7.0%) of the patients in the treatment group and 60 (10.7%) of the patients in the control group (relative risk [RR], 0.65; 95% confidence interval [CI], 0.45 to 0.96; risk difference [RD], -3.8%; 95% CI, -7.2% to -0.4%; p = 0.03). The treatment intervention demonstrated a similar effect at 90 days (RR, 0.59; 95% CI, 0.37 to 0.93) and 365 days (RR, 0.62; 95% CI, 0.44 to 0.87). Secondary analyses demonstrated that the effect was driven by a reduction in superficial surgical site infections.

CONCLUSIONS

Among tibial plateau, pilon, or calcaneal fracture patients at elevated risk for surgical site infection, a high perioperative FiO 2 lowered the risk of surgical site infection. The findings support the use of this intervention, although the benefit appears to mostly be in reduction of superficial infections.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Systematic review and meta-analysis: association between obesity/overweight and surgical complications in IBD

PURPOSE

While the prevalence of obesity in inflammatory bowel disease (IBD) patients is rapidly increasing, it is unclear whether obesity affects surgical outcomes in this population. This meta-analysis aims to assess the impact of obesity/overweight on patients undergoing surgery for IBD.

METHODS

Databases (PubMed, Web of Science, Cochrane Library, and Springer) were searched through September 2021. The meta-analysis included patients with surgically treated IBD to investigate the impact of obesity/overweight on this population. Primary outcomes included overall complications, infectious complications, noninfectious complications, and conversion to laparotomy.

RESULTS

Fifteen studies totaling 12,622 IBD patients were enrolled. Compared with nonobese (including overweight) patients, obese IBD patients have increased the risk in terms of overall complications (OR = 1.45, p < 0.001), infectious complications (OR = 1.48, p = 0.003) (especially wound complications), as well as conversion to laparotomy (OR = 1.90, p < 0.001). Among the noninfectious complications, only the incidence of visceral injury (OR = 2.36, p = 0.05) had significantly increased. Compared with non-overweight patients, the risk of developing wound complications (OR = 1.65, p = 0.01) and sepsis (OR = 1.73, p = 0.007) were increased in overweight patients, but the rates of overall complications (OR = 1.04, p = 0.81), infectious complications (OR = 1.31, p = 0.07), and conversion to laparotomy (OR = 1.33, p = 0.08) associated with body mass index (BMI) were not significantly different.

CONCLUSION

Obesity is a risk factor for surgical complications in IBD patients, mainly reflected in infectious complications. Moreover, obese patients seem to have a more common chance of developing surgical complications than overweight patients.

Fraction of Inspired Oxygen During General Anesthesia for Non-Cardiac Surgery: Systematic Review and Meta-Analysis

Background

Controversy exists regarding the effects of a high versus a low intraoperative fraction of inspired oxygen (FiO₂) in adults undergoing general anesthesia. This systematic review and meta‐analysis investigated the effect of a high versus a low FiO₂ on postoperative outcomes.

Methods

PubMed and Embase were searched on March 22, 2022 for randomized clinical trials investigating the effect of different FiO₂ levels in adults undergoing general anesthesia for non‐cardiac surgery. Two investigators independently reviewed studies for relevance, extracted data, and assessed risk of bias. Meta‐analyses were performed for relevant outcomes, and potential effect measure modification was assessed in subgroup analyses and meta‐regression. The evidence certainty was evaluated using GRADE.

Results

This review included 25 original trials investigating the effect of a high (mostly 80%) versus a low (mostly 30%) FiO₂. Risk of bias was intermediate for all trials. A high FiO₂ did not result in a significant reduction in surgical site infections (OR: 0.91, 95% CI 0.81–1.02 [p = .10]). No effect was found for all other included outcomes, including mortality (OR = 1.27, 95% CI: 0.90–1.79 [p = .18]) and hospital length of stay (mean difference = 0.03 days, 95% CI −0.25 to 0.30 [p = .84). Results from subgroup analyses and meta‐regression did not identify any clear effect modifiers across outcomes. The certainty of evidence (GRADE) was rated as low for most outcomes.

Conclusions

In adults undergoing general anesthesia for non‐cardiac surgery, a high FiO₂ did not improve outcomes including surgical site infections, length of stay, or mortality. However, the certainty of the evidence was assessed as low.

The radiographic soft tissue thickness is associated with wound complications after open reduction and internal fixation of patella fractures

Background

Displaced patella fracture is commonly treated with open reduction and internal fixation (ORIF). Wound complications after surgery often lead to prolonged hospitalization and dissatisfaction of patients. Periarticular adiposity and swelling may be associated with wound complications. The purpose of this study is to determine the relationship between periarticular soft tissue thickness and wound complications after ORIF of patella fractures.

Methods

We retrospectively studied 237 patients undergoing ORIF for patella fractures from June 2017 to February 2021 at our institution. We established periarticular soft tissue thickness ratio (PSTTR) to evaluate soft tissue status on lateral knee X-ray radiographs. Univariate analysis was performed to identify the association between PSTTR and postoperative wound complication. A receiver-operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of PSTTR.

Results

The incidence of postoperative wound complication was 10.5%. Minor wound complication occurred in 24 patients, and major wound complication occurred in one patient. The average femoral PSTTR (fPSTTR) was 0.94 ± 0.17 and the average tibial PSTTR (tPSTTR) was 0.66 ± 0.16. fPSTTR proved to be associated with postoperative wound complication. In the ROC analysis of fPSTTR predicting postoperative wound complication, the area under curve (AUC) was 0.676, which indicated a moderate predictive value.

Conclusions

PSTTR was a feasible method to assess periarticular soft tissue. The increased fPSTTR was associated with wound complications after ORIF of patella fractures.

Functional panniculectomy vs cosmetic abdominoplasty: Multicenter analysis of risk factors and complications

BACKGROUND

Amidst the rising trend of bariatric surgical procedures being performed across the country and around the world, patients seeking functional panniculectomy after massive weight loss represent a different population than those seeking cosmetic abdominoplasty. The purpose of this study was to determine whether certain complications are more likely to occur in patients undergoing functional panniculectomy, as well as identify risk factors that are implicated in the occurrence of adverse events.

METHODS

Retrospective cohort study was conducted of patients undergoing cosmetic abdominoplasty and functional panniculectomy in North America between 2015 and 2019 using the National Surgical Quality Improvement Program database sponsored by the American College of Surgeons. Comorbidities and postoperative complications between these two cohorts were analyzed with appropriate statistics.

RESULTS

During the study interval, 11,137 patients underwent excision of excessive infraumbilical abdominal skin, including 57.4% (n = 6397) patients undergoing functional panniculectomy and 42.6% (n = 4740) patients undergoing cosmetic abdominoplasty. Patients undergoing functional panniculectomy were significantly more likely to have comorbidities than those undergoing cosmetic abdominoplasty (p < .001). Overall adverse events (p < .001), medical complications (p = .047), surgical complications (p < .001), related readmission (p < .001), and related reoperation (p < .001) were significantly higher in patients undergoing functional panniculectomy. Surgical complications significantly higher in functional panniculectomy included superficial incisional infection (p < .001), deep incisional infection (p < .001), organ/space infection (p < .001), dehiscence (p = .003), and bleeding requiring transfusion (p = .003).

CONCLUSIONS

Patients undergoing functional panniculectomy are significantly more likely to have comorbidities and experience postoperative wound infection, dehiscence, sepsis, bleeding, related readmission, and related reoperation.

Dangers of hyperoxia

Oxygen (O2) toxicity remains a concern, particularly to the lung. This is mainly related to excessive production of reactive oxygen species (ROS). Supplemental O2, i.e. inspiratory O2 concentrations (FIO2) > 0.21 may cause hyperoxaemia (i.e. arterial (a) PO2 > 100 mmHg) and, subsequently, hyperoxia (increased tissue O2 concentration), thereby enhancing ROS formation. Here, we review the pathophysiology of O2 toxicity and the potential harms of supplemental O2 in various ICU conditions. The current evidence base suggests that PaO2 > 300 mmHg (40 kPa) should be avoided, but it remains uncertain whether there is an "optimal level" which may vary for given clinical conditions. Since even moderately supra-physiological PaO2 may be associated with deleterious side effects, it seems advisable at present to titrate O2 to maintain PaO2 within the normal range, avoiding both hypoxaemia and excess hyperoxaemia.

Wavelength and pulse energy optimization for detecting hypoxia in photoacoustic imaging of the neonatal brain: a simulation study

Cerebral hypoxia is a severe injury caused by oxygen deprivation to the brain. Hypoxia in the neonatal period increases the risk for the development of neurological disorders, including hypoxic-ischemic encephalopathy, cerebral palsy, periventricular leukomalacia, and hydrocephalus. It is crucial to recognize hypoxia as soon as possible because early intervention improves outcomes. Photoacoustic imaging, using at least two wavelengths, through a spectroscopic analysis, can measure brain oxygen saturation. Due to the spectral coloring effect arising from the dependency of optical properties of biological tissues to the wavelength of light, choosing the right wavelength-pair for efficient and most accurate oxygen saturation measurement and consequently quantifying hypoxia at a specific depth is critical. Using a realistic neonate head model and Monte Carlo simulations, we found practical wavelength-pairs that quantified regions with hypoxia most accurately at different depths down to 22 mm into the cortex neighboring the lateral ventricle. We also demonstrated, for the first time, that the accuracy of the sO2 measurement can be increased by adjusting the level of light energy for each wavelength-pair. Considering the growing interest in photoacoustic imaging of the brain, this work will assist in a more accurate use of photoacoustic spectroscopy and help in the clinical translation of this promising imaging modality. Please note that explaining the effect of acoustic aberration of the skull is not in the scope of this study.

Incidence and Predictors of Surgical Site Infection Complications in Diabetic Patients Undergoing Lower Limb Amputation

BACKGROUND

Surgical site infections (SSIs) following lower extremity amputations (LEAs) are a major cause of patient morbidity and mortality. The objectives of this study are to investigate the annual incidence of SSI and risk factors associated with SSI after LEA in diabetic patients.

METHODS

LEAs performed on diabetic patients between 2005 and 2017 were retrospectively analyzed from the American College of Surgeons National Surgical Quality Improvement Program database. Incidence rates were calculated and analyzed for temporal change. Multivariable logistic regression was conducted to identify the independent predictors of SSIs in LEA.

RESULTS

In 21,449 diabetic patients, the incidence of SSIs was 6.8% after LEA, with an overall decreasing annual trend (P = 0.013). Amputation location (below-knee in reference to above-knee) [OR (95% CI): 1.35 (1.20 - 1.53), P <0.001], smoking [OR (95% CI): 1.25 (1.11 - 1.41), P <0.001)], female sex [OR (95% CI): 1.16 (1.03 - 1.30)], preoperative sepsis [OR (95% CI): 1.24 (1.10 - 1.40), P <0.001], P = 0.013], emergency status [OR (95% CI): 1.38 (1.17 - 1.63), P <0.001], and obesity [OR (95% CI): 1.59 (1.12 - 2.27), P = 0.009] emerged as independent predictors of SSIs, while moderate/severe anemia emerged as a risk-adjusted protective factor [OR (95% CI): 0.75 (0.62 - 0.91), P = 0.003]. Sensitivity analysis found that moderate/severe anemia, not body mass index (BMI) class, remained a significant risk factor in the development of SSIs in below-the-knee amputations; in contrast, higher BMI, not preoperative hematocrit, was significantly associated with an increased risk for SSI in above-the-knee amputations.

CONCLUSIONS

The incidence of SSIs after LEA in diabetic patients is decreasing. Overall, below-knee amputation, smoking, emergency status, and preoperative sepsis appeared to be associated with SSIs. Obesity increased SSIs in above-the-knee amputations, while moderate/severe preoperative anemia appears to protect against below-the-knee SSIs. Surgeons should take predictors of SSI into consideration while optimizing care for their patients, and future studies should investigate the role of preoperative hematocrit correction and how it may influence outcomes positively or negatively.

Effect of Peri-Operative Hyperoxygenation on Surgical Site Infection in Patients Undergoing Emergency Abdominal Surgery: A Randomized Controlled Trial

Background: The rationale for hyperoxygenation in controlling surgical site infection (SSI) has been described in many studies yet has not been defined clearly. Some studies in colorectal surgery have reported beneficial effects, whereas studies in gynecologic surgery have reported either no effect or a deleterious effect. This study assessed the effectiveness of hyperoxygenation on the reduction of SSI in patients undergoing emergency abdominal surgery. Patients and Methods: Eligible patients were assigned randomly to two groups (study group, 80% oxygen or control group, 30% oxygen). The patients in the study group received 80% oxygen and the patients in the control group received 30% oxygen intra-operatively and for two hours after surgery. Arterial blood gas analysis was done after resuscitation, at the end of the surgery, and at two hours after extubation. All patients were assessed for SSI, post-operative nausea and vomiting, and respiratory complications. Patients were followed post-operatively for 14 days. Surgical site infection was diagnosed according to U.S. Centers for Disease Control and Infection (CDC) criteria and by aerobic wound cultures. Results: After exclusion, 85 patients in the control group and 93 patients in the study group were analyzed. There was no difference for baseline, intra-operative, and post-operative characteristics between the two groups, except for higher oxygen saturation at closure and two hours post-operatively, in the 80% group (p = 0.01). Surgical site infection occurred in 29 patients (34.11%) in 30% fraction of inspired oxygen (F_IO₂) group and in 19 patients (20.43%) in 80% F_IO₂ group (p = 0.04). The risk of SSI was 59% lower in the 80% F_IO₂ group (adjusted odds ratio, 0.41; 95% confidence interval [CI], 0.19-0.88 vs. the 30% F_IO₂ group). There were no differences in post-operative nausea and vomiting and respiratory complications between the two treatment groups. Conclusions: Administration of 80% peri-operative hyperoxygenation in emergency abdominal surgery reduces SSI and is a cost-effective method.

Effect of intra-operative high inspired fraction of oxygen on postoperative nausea and vomiting in children undergoing surgery: A prospective randomised double-blind study

BACKGROUND

Administration of high inspired fraction of oxygen (FiO2) during anaesthesia has been proposed to decrease postoperative nausea and vomiting (PONV) in adults but has not been extensively studied in children.

OBJECTIVES

The primary objective of this study was to evaluate the effect of 80% FiO2 on the incidence of PONV in children undergoing surgery.

DESIGN

Prospective, randomised, study.

SETTING

Single-centre, teaching hospital.

PATIENTS

Children of either gender in the age group of 5 to 15 years scheduled for elective surgeries were assessed for eligibility. In cases of emergency surgeries; patients receiving supplemental oxygen pre-operatively or on mechanical ventilation; sepsis; bowel obstruction or ischaemia; poor nutritional status; anaemia (Hb <8 g%) or surgeries lasting less than 1 h or greater than 4 h were excluded from the study.

INTERVENTIONS

After induction of anaesthesia, children were randomised to receive either 30 or 80% oxygen in air, till the end of surgery.

MAIN OUTCOME MEASURES

Incidence of PONV within 24 h; surgical site infections (SSI)s; serum serotonin and TNF-α levels and the incidence of postoperative pulmonary complications (PPC)s were studied.

RESULTS

The overall 24 h incidence of PONV was not different between the low and high FiO2 groups [24 vs. 23%; P = 0.84; odds ratio (OR) 0.92; 95% confidence interval (CI), 0.44 to 2.06]. The incidence of SSIs (15 vs. 12%; P = 0.61; OR 0.77; 95% CI, 0.28 to 2.10) and PPCs (12 vs. 8%; P = 0.38; OR 0.59; 95% CI, 0.18 to 1.92) were not significant between the low and high FiO2 groups, respectively. Intragroup and intergroup comparisons of serum serotonin and TNF-α showed no significant difference either at baseline or at the end of surgery.

CONCLUSION

High intra-operative FiO2 of 80% does not provide additional protection against PONV in children.

TRIAL REGISTRATION

The study was registered with Clinical Trials Registry of India (CTRI) with trial registration no: CTRI/2018/07/014974.

Molecular Biomarkers of Oxygen Therapy in Patients with Diabetic Foot Ulcers

Hyperbaric oxygen therapy (HBOT) and topical oxygen therapy (TOT) including continuous diffuse oxygen therapy (CDOT) are often utilized to enhance wound healing in patients with diabetic foot ulcerations. High pressure pure oxygen assists in the oxygenation of hypoxic wounds to increase perfusion. Although oxygen therapy provides wound healing benefits to some patients with diabetic foot ulcers, it is currently performed from clinical examination and imaging. Data suggest that oxygen therapy promotes wound healing via angiogenesis, the creation of new blood vessels. Molecular biomarkers relating to tissue inflammation, repair, and healing have been identified. Predictive biomarkers can be used to identify patients who will most likely benefit from this specialized treatment. In diabetic foot ulcerations, specifically, certain biomarkers have been linked to factors involving angiogenesis and inflammation, two crucial aspects of wound healing. In this review, the mechanism of how oxygen works in wound healing on a physiological basis, such as cell metabolism and growth factor signaling transduction is detailed. Additionally, observable clinical outcomes such as collagen formation, angiogenesis, respiratory burst and cell proliferation are described. The scientific evidence for the impact of oxygen on biomolecular pathways and its relationship to the outcomes in clinical research is discussed in this narrative review.

Postoperative Pain Treatment With Continuous Local Anesthetic Wound Infusion in Patients With Head and Neck Cancer: A Nonrandomized Clinical Trial

Importance

Up to 80% of patients with head and neck cancer undergoing ablative surgery and neck dissection develop postoperative pain with detrimental effects on quality of life that also contributes to neuropathic and chronic postoperative pain.

Objective

To investigate the association of continuous local anesthetic wound infusion with pain management after head and neck surgery.

Design, Setting, and Participants

This prospective, longitudinal, nonrandomized clinical study carried out in a single tertiary referral center (December 1, 2015, to July 1, 2017) included 2 groups of 30 patients. Patients were consecutively enrolled and presented for ablative head and neck surgery including selective neck dissection and studied from the preoperative through the fourth postoperative day.

Interventions

The control group was treated according to a standardized escalating oral treatment protocol (ibuprofen, metamizole, opioids). The intervention group was treated with an intraoperatively applied pain catheter (InfiltraLong plus FuserPump, Pajunk, ropivacaine, 0.2%, 3 mL/h) that was removed 72 hours after operating.

Main Outcomes and Measures

Average and maximum pain intensities on a numeric rating scale; quality of life using the acute version of the validated 36-Item Short Form Survey; and neuropathic pain using the validated 12-Item painDETECT questionnaire. Consumption of opioid and nonopioid analgesics and evaluation of catheter-associated complications.

Results

During postoperative days 1 through 4, patients of the intervention group (mean [SD] age, 63.2 [13.3 years; 9 [30%] women) experienced lower mean (SD) (1.6 [1.4] vs 2.7 [1.8]; η2p = 0.09 [0.01-0.21]) and maximum (2.4 [2.2] vs 4.2 [2.0]; η2p = 0.11 [0.01-0.24]) pain intensities compared with the control group (mean [SD] age, 62.5 [13.6] years; 5 [17%] women). The intervention group also reported less neuropathic pain (mean [SD], 5.4 [3.4] vs 7.6 [5.1]; η2p = 0.09 [0.004 - 0.22]) and higher quality of life regarding vitality (56.2 [21.5] vs 43.8 [20.9], r = 0.29; 95% CI, 0.01-0.52) and pain (66.8 [27.3] vs 49.5  [27.7], r = 0.31; 95% CI, 0.04-0.54). Patients from the intervention group requested nonopioid analgesics considerably less often (n = 17 [57% ]vs n = 29 [97%]; ϕ = 0.47; 95% CI, 0.30-0.67) associated with a noticeably lower need to escalate pain treatment (n = 3 [10%] vs n = 9 [30%]; mean [SD] ibuprofen dose: 500 [173] mg vs 1133 [650] mg; r = 0.64; 95% CI, 0.02-0.91). No catheter-associated complications were observed.

Conclusions and Relevance

Continuous anesthetic wound infusion is associated with reduced postoperative pain and decreased demand for analgesics. It therefore expands the treatment options for postoperative pain in head and neck cancer.

Trial Registration

German Clinical Trials Register: DRKS00009378.