Wound hypoxia and acidosis limit neutrophil bacterial killing mechanisms

Chlorella-encapsulated living hydrogel based on gelatin and carrageenan with oxygen production, hemostatic and antibacterial capacity for promoting wound healing

Hypoxia can prolong the healing time of wounds and oxygen delivery to the hypoxic tissue has been reported an effective strategy for promoting wound regeneration. Bacterial infections can interfere with the wound healing process, leading to poor skin regeneration and even more serious complications, which is also an urgent issue to be solved during the process of wound healing. To address the problem of delayed wound healing caused by hypoxia and bacterial infections, we fabricated a series of Chlorella-loaded hydrogels (CK) using gelatin, κ-carrageenan and I-carrageenan as matrixes, which introduced Chlorella and ampicillin conferred oxygen-producing and antimicrobial capacity to the hydrogel. The CK hydrogels possessed good mechanical and adhesive properties, as well as the capability of efficient and sustained oxygen release. The hydrogels possessed outstanding hemostatic ability, excellent blood and cell compatibility, which also owned excellent antibacterial capacity against E. coli and S. aureus. More notably, the in vivo evaluation revealed that the hydrogel can accelerate wound healing by promoting collagen deposition, which may as a promising potential wound dressing for hypoxic wound healing.

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.

Efficacy of continuous topical oxygen therapy in hard-to-heal wounds in Colombia: a retrospective analysis

OBJECTIVE

To evaluate the use of continuous topical oxygen therapy (cTOT) in hard-to-heal or chronic wounds in Colombia, South America.

METHOD

This multicentre, retrospective analysis studied the efficacy of treating hard-to-heal wounds using a cTOT device in patients over a 3-6-month period. Data were collected retrospectively from patient records. Descriptive statistics were used to summarise the characteristics of the patient population, types of wounds and treatment outcomes. Patients were divided into two groups: a continuous cTOT-treated group (n=47) and a discontinuous cTOT-treated group (n=22). The duration of treatment and wound size reduction were compared. Changes in pain medication usage and the incidence of infections were also analysed.

RESULTS

A total of 69 patients were included in the analysis. Complete healing was achieved in 64% of the continuous cTOT-treated group and 36% of the discontinuous cTOT-treated group, with most patients being pain-free and not requiring medication after treatment.

CONCLUSION

The results of this study suggest the benefits of cTOT over traditional treatments in accelerating wound healing and reducing pain, medication necessity and wound infection.

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.

Impact of single versus dual arterial supply on perfusion and function in finger replantation after complex hand injuries

Finger amputations following complex hand injuries (CHI) pose a significant challenge in hand surgery due to severe tissue trauma and neurovascular damage, necessitating precise arterial repair. While restoring arterial perfusion is critical, it remains unclear whether reconstructing both proper palmar digital arteries is required for optimal outcomes. This study evaluates whether restoring one or both arteries in finger replantation after complex injuries impacts perfusion and overall outcomes. In this retrospective, cross-sectional, follow-up study, we investigated patients with finger amputations following CHI admitted to the high-volume regional hand trauma center between January 2013 and December 2020. Perfusion has been assessed using FLIR thermal imaging and laser speckle contrast analysis. Functional outcomes and quality of life scores were measured using standardized questionnaires. Sensory assessments, along with pain and grip strength measurements were also conducted. A total of 31 patients were included in the study. Thermal imaging showed a significantly higher finger surface temperature in patients with two-artery reconstruction. Laser speckle contrast analysis confirmed better perfusion, though not statistically significant. Functional and quality-of-life scores were similar across groups, except for significantly improved temperature sensation in the two-artery group. In conclusion, reconstructing both arteries in finger replantation following CHI isn't essential for good outcomes if one artery provides adequate perfusion, but dual reconstruction may improve perfusion and temperature sensation.

Inadvertent perioperative hypothermia and surgical site infections after liver resection

BACKGROUND

In the overall surgical population, inadvertent perioperative hypothermia has been associated with an increased incidence of surgical site infection (SSI). However, recent clinical trials did not validate this notion. This study aimed to investigate the potential correlation between inadvertent perioperative hypothermia and SSIs following liver resection.

METHODS

This retrospective cohort study included all consecutive patients who underwent liver resection between January 2019 and December 2021 at the First Affiliated Hospital, Zhejiang University School of Medicine. Perioperative temperature managements were implemented for all patients included in the analysis. Estimated propensity score matching (PSM) was performed to reduce the baseline imbalances between the normothermia and hypothermia groups. Before and after PSM, univariate analyses were performed to evaluate the correlation between hypothermia and SSI. Multivariate regression analysis was performed to determine whether hypothermia was an independent risk factor for postoperative transfusion and major complications. Subgroup analyses were performed for diabetes mellitus, age > 65 years, and major liver resection.

RESULTS

Among 4000 patients, 2206 had hypothermia (55.2%), of which 150 developed SSI (6.8%). PSM yielded 1434 individuals in each group. After PSM, the hypothermia and normothermia groups demonstrated similar incidence rates of SSI (7.0% vs. 6.3%, P = 0.453), postoperative transfusion (13.7% vs. 13.3%, P = 0.743), and major complications (10.1% vs. 9.0%, P = 0.309). Univariate regression analysis revealed no significant effects of hypothermia on the incidence of SSI in the group with the highest hypothermia exposure [odds ratio (OR) = 1.25, 95% confidence interval (CI): 0.84-1.87, P = 0.266], the group with moderate exposure (OR = 1.00, 95% CI: 0.65-1.53, P = 0.999), or the group with the lowest exposure (OR = 1.11, 95% CI: 0.73-1.65, P = 0.628). The subgroup analysis revealed similar results. Regarding liver function, patients in the hypothermia group demonstrated lower γ-glutamyl transpeptidase (37 vs. 43 U/L, P < 0.001) and alkaline phosphatase (69 vs. 72 U/L, P = 0.016). However, patients in the hypothermia group exhibited prolonged activated partial thromboplastin time (29.2 vs. 28.6 s, P < 0.001).

CONCLUSIONS

In our study of patients undergoing liver resection, we found no significant association between mild perioperative hypothermia and SSI. It might be due to the perioperative temperature managements, especially active warming measures, which limited the impact of perioperative hypothermia on the occurrence of SSI.

The impact of smoking on ventral and inguinal hernia repair: a systematic review and meta-analysis

PURPOSE

Individual studies indicate poorer outcomes for smokers after hernia repair. Previous meta-analyses have examined the impact of smoking on specific outcomes such as recurrence and surgical site infection, but there has been a lack of comprehensive consensus or systematic review on this subject. Addressing this gap, our study undertakes a systematic review and meta-analysis to assess the impact of smoking on the outcomes of ventral hernia repair (VHR) and inguinal hernia repair.

SOURCE

A thorough search of Cochrane Central, Scopus, SciELO, and PubMed/MEDLINE, focusing on studies that examined the effect of smoking on inguinal and VHR outcomes was conducted. Key outcomes evaluated included recurrence, reoperation, surgical site occurrences (SSO), surgical site infection (SSI), and seroma.

PRINCIPAL FINDINGS

Out of 3296 screened studies, 42 met the inclusion criteria. These comprised 25 studies (69,295 patients) on VHR and 17 studies (204,337 patients) on inguinal hernia repair. The analysis revealed that smokers had significantly higher rates of recurrence (10.4% vs. 9.1%; RR 1.48; 95% CI [1.15; 1.90]; P < 0.01), SSO (13.6% vs. 12.7%; RR 1.44; 95% CI [1.12; 1.86]; P < 0.01) and SSI (6.6% vs. 4.2%; RR 1.64; 95% CI [1.38; 1.94]; P < 0.01) following VHR. Additionally, smokers undergoing inguinal hernia repair showed higher recurrence (9% vs. 8.7%; RR 1.91; 95% CI [1.21; 3.01]; P < 0.01), SSI (0.6% vs. 0.3%; RR 1.6; 95% CI [1.21; 2.0]; P < 0.001), and chronic pain (9.9% vs. 10%; RR 1.24; 95% CI [1.06; 1.45]; P < 0.01) rates. No significant differences were observed in seroma (RR 2.63; 95% CI [0.88; 7.91]; P = 0.084) and reoperation rates (RR 1.48; 95% CI [0.77; 2.85]; P = 0.236) for VHR, and in reoperation rates (RR 0.99; 95% CI [0.51; 1.91]; P = 0.978) for inguinal hernias between smokers and non-smokers. Analysis using funnel plots and Egger's test showed the absence of publication bias in the study outcomes.

CONCLUSION

This comprehensive meta-analysis found statistically significant increases in recurrence rates, and immediate postoperative complications, such as SSO and SSI following inguinal and VHR. Also, our subgroup analysis suggests that the MIS approach seems to be protective of adverse outcomes in the smokers group. However, our findings suggest that these findings are not of clinical relevance, so our data do not support the necessity of smoking cessation before hernia surgery. More studies are needed to elucidate the specific consequences of smoking in both inguinal and ventral hernia repair.

PROSPERO REGISTRATION

ID CRD42024517640.

Do the results of the OXYGEN trial change if analyzed as "as-treated?": A secondary analysis of the OXYGEN trial

OBJECTIVE

To determine if the results of the OXYGEN trial changed using an "as-treated" approach instead of the original "intention-to-treat" approach. The multi-center randomized controlled OXYGEN trial aimed to determine the effectiveness of high FiO2 in decreasing infection rates for high-risk tibial plateau, tibial pilon, and calcaneus fractures.

METHODS

A secondary analysis of a multi-center randomized controlled trial conducted at 29 US trauma centers was performed. A total of 1231 patients aged 18-80 years with tibial plateau, tibial pilon, or calcaneus fractures thought to be at elevated risk of infection were enrolled. Patients were randomly assigned to receive inspired oxygen at a concentration of 80 % FiO2 (treatment) or 30 % FiO2 (control). Adherence was defined using two different criteria. Criterion 1 required at least 80 % of the surgery time ≤40 % FiO2 for the control group or ≥70 % FiO2 for the treatment group. Criterion 2 required at least 80 % of surgery time within 20-40 % (control) or 70-90 % FiO2 (treatment). The primary outcome was surgical site infection (SSI) within 182 days of definitive fracture fixation. Secondary outcomes were deep and superficial surgical site infections within 90, 182, and 365 days of definitive fixation.

RESULTS

Under Criterion 1, the primary outcome occurred in 7 % (38/523) and 10 % (49/471) of patients in the treatment and control groups, respectively (p = 0.10). Deep infection occurred in 30 (6 %) treatment and 30 (6 %) control patients (p = 0.75). Superficial infection occurred in 9 (2 %) treatment and 20 (4 %) control patients (RR, 0.41; p = 0.03). Using Criterion 2, the primary outcome occurred in 7 % (36/498) of treatment and 10 % (48/468) of control patients (p = 0.12). Deep infection occurred in 28 (6 %) treatment and 29 (6 %) control patients (p = 0.81). Superficial infection occurred in 9 (2 %) treatment and 20 (4.3 %) control patients (RR = 0.43; p = 0.03).

CONCLUSIONS

When re-analyzing based on which patients actually received high or control levels of perioperative oxygen fraction, the results are somewhat consistent with the original "intent-to-treat" analysis. Specifically, high perioperative oxygen lowered the risk of superficial SSI but did not affect deep infections.

Would hyperbaric oxygen therapy be a supportive treatment method for refractory idiopathic granulomatous mastitis?

BACKGROUND

Refractory IGM causes patients to use antibiotics, steroid therapy, immunosuppressive agents for a very long time and even leads to surgical procedures resulting in the loss of breast tissue. Hyperbaric Oxygen Therapy (HBOT) is a frequently used method in the treatment of wounds that are difficult to heal. We thought that HBOT would be an alternative treatment method for refractory IGM patients.

METHODS

It is a retrospective cohort study on refractory IGM patients conducted at three tertiary care treatment centers between January 2021 and July 2023. The patients were evaluated in two groups: those who only took steroid treatment and those who received HBOT and steroid treatment. The demographic and clinical characteristics of the patients, the types of treatment applied and their responses to treatment were evaluated.

RESULTS

There were no significant differences generally in the demographic and clinical features in both groups. The incidence of multicentric GM was found to be higher in the HBOT group (66.67 %; p = 0.044). Although the recovery results were similar in both groups, the average daily steroid dose and duration of drug use were found to be higher in the group receiving only steroid treatment (16 mg vs. 4 mg and 270 days vs. 30 days) (p < 0.001).

CONCLUSION

In our study, we showed for the first time in the literature that HBOT is effective in the treatment of refractory IGM patients. Our study needs to be supported by prospective studies evaluating cost effectiveness and possible long term complications.

Aberrant Oxygen Concentrations Induce Systemic Inflammation in a Murine Model

INTRODUCTION

Hypoxia is a significant cause of secondary insult in the critically ill trauma or surgical patient. The cause of increased mortality following a brief period of hypoxia is not well understood. The aim of this study is to determine the effect of acute, isolated deviations in oxygen concentration on proinflammatory cytokine release and markers of endothelial stress in a murine model.

METHODS

Mice were randomized to either control, hypoxia, or hyperoxia group. The control group was exposed to room air for 60 min, the hyperoxia group was exposed to 70% fraction of inspired oxygen, and the hypoxia group was exposed to 10% fraction of inspired oxygen for 60 min. Whole blood collection was completed via cardiac puncture. Serum concentrations of proinflammatory cytokines and endothelial stress markers were analyzed via enzyme-linked immunosorbent assay.

RESULTS

Following exposure to hypoxic conditions, there was a significant increase in interleukin (IL)-1α (IL-1 α), IL-1 β, IL-3, IL-4, IL-6, IL-10, tumor necrosis factor α . Following exposure to hyperoxic conditions, there was a significant increase in monocyte chemoattractant protein-1 and regulated upon activation normal T cell expressed and presumably secreted, as well as a significant decrease in IL-12, and IL-17. No clinically significant difference was noted in serum concentration of endothelial stress markers between the treatment groups.

DISCUSSION

Exposure to oxygen extremes induces systemic inflammation as measured by proinflammatory cytokines in a murine model. Hyperoxia also demonstrates the ability to downregulate certain inflammatory pathways while inducing others. No effect on serum concentration of endothelial stress markers is observed following acute, isolated hypoxic or hyperoxic conditions.

A retrospective cohort study on enhanced recovery after surgery (ERAS) in patients with diabetic foot ulcer

Enhanced recovery after surgery (ERAS) has been successfully integrated into a diverse array of surgical fields to improve the quality and efficacy of treatment intervention. Nonetheless, the application of the ERAS protocol for patients with diabetic foot ulcer (DFU) subsequent to undergoing surgical procedures has not been previously explored. Therefore, this study aimed to investigate the effect of an enhanced recovery protocol on perioperative outcomes in patients with DFU following surgical procedures. A retrospective analysis was conducted on 112 patients with DFU who underwent surgery between January 2020 and December 2021 at a tertiary referral care center. In total, 57 patients received standard perioperative care (the non-ERAS group), and 55 patients received ERAS care (the ERAS group). The primary outcomes included the length of stay (LOS), wound healing time, patient satisfaction, and costs, serving as the basis for assessing the effectiveness of the two approaches. Secondary outcomes included preoperative anxiety (APAIS score), nutritional status (PG-SGA), pain (NRS score), the incidence of lower-extremity deep vein thrombosis (DVT), the reduction in lower-limb circumference, and the activity of daily living scale (Barthel Index). The ERAS group exhibited significantly shorter LOS (11.36 vs. 26.74 days; P < 0.001) and lower hospital costs (CNY 62,165.27 vs. CNY 118,326.84; P < 0.001), as well as a higher patient satisfaction score and Barthel Index score (P < 0.05). Additionally, we found a lower APAIS score, incidence of DVT, and circumference reduction in lower limbs in the ERAS group compared to the non-ERAS group (P < 0.05). In comparison, the wound healing time, nutritional status, and pain levels of participants in both groups showed no significant difference (P > 0.05). By reducing the LOS and hospital costs, and by minimizing perioperative complications, the ERAS protocol improves the quality and efficacy of treatment intervention in patients with DFU who underwent surgical procedures.Trial registration number: ChiCTR 2200064223 (Registration Date: 30/09/2022).

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

DISCUSSION

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

Strikingly High Rates of Periprosthetic Joint Infection Following Revision Surgery for Periprosthetic Fractures Regardless of Surgery Timing

BACKGROUND

Periprosthetic fractures following total hip arthroplasty (THA) often occur in the early postoperative period. Recent data has indicated that early revisions are associated with higher complication rates, particularly periprosthetic joint infection (PJI). The purpose of this study was to assess the effect of timing of periprosthetic fracture surgery on complication rates. We hypothesized that complication rates would be significantly higher in revision surgeries performed within 3 months of the index THA.

METHODS

The Medicare Part A claims database was queried from 2010 to 2017 to identify patients who underwent surgery for a periprosthetic fracture following primary THA. Patients were divided based on time between index and revision surgeries: <1, 1 to 2, 2 to 3, 3 to 6, 6 to 9, 9 to 12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics, comorbidities, and types of revision surgery.

RESULTS

Of 492,340 THAs identified, 4,368 (0.9%) had a subsequent periprosthetic fracture requiring surgery: 1,725 (39.4%) at <1 month, 693 (15.9%) at 1 to 2 months, 202 (4.6%) at 2 to 3 months, 250 (5.7%) at 3 to 6 months, 134 (3.1%) at 6 to 9 months, 85 (19.4%) at 9 to12 months, and 1,279 (29.3%) at >12 months. The risk of PJI was 11.0% in the <1 month group, 11.1% at 1 to 2 months, 7.9% at 2 to 3 months, 6.8% at 3 to 6 months, 8.2% at 6 to 9 months, 9.4% at 9 to 12 months, and 8.5% at >12 months (P = .12). Adjusting for confounding factors, risk of PJI following periprosthetic fracture surgery was similar regardless of timing (P > .05). Rates of subsequent dislocation and aseptic loosening were also similar regardless of timing.

CONCLUSIONS

The risk of PJI following repeat surgery for a periprosthetic fracture was strikingly high regardless of timing (6.8 to 11.1%), underscoring the high-risk of complications.

Early Periprosthetic Femur Fractures After Primary Cementless Total Hip Arthroplasty: High Risk of Periprosthetic Joint Infection and Subsequent Reoperation

BACKGROUND

Periprosthetic femur fracture (PFF) following total hip arthroplasty (THA) is a leading cause of early reoperation. The objective of this study was to compare rates of periprosthetic joint infection (PJI) and reoperation following PFFs occurring early postoperatively to those that occurred late.

METHODS

We retrospectively identified 173 consecutive surgically managed PFFs following primary THA. Cases were categorized as "early" if they occurred within 90 days of THA (n = 117) or "late" if they occurred following the initial 90 days (n = 56). Mean age at time of PFF was 68 years (range, 26 to 96) and 60% were women. Mean body mass index was 29 (range, 16 to 52). Mean follow-up was 2 years (range, 0 to 13). Kaplan-Meier survival analysis estimated cumulative incidences of PJI and reoperation.

RESULTS

Early PFFs had higher 2-year cumulative incidence of PJI (11% versus 0%, P < .001) and reoperation (24% versus 13%, P = .110). Following early PFF, 27 patients required reoperation (ie, 13 for PJI, 5 for instability, 2 for re-fracture, 2 for painful hardware, 2 for non-union, 1 for adverse local tissue reaction, 1 for aseptic loosening, and 1 for leg-length discrepancy). Following late PFF, 5 patients required reoperation (ie, 3 for instability, 1 for re-fracture, and 1 for non-union).

CONCLUSIONS

There are greater incidences of PJIs and overall reoperations following early PFFs compared to late PFFs after THA. In addition to focusing efforts on prevention of early PFFs, surgeons should consider antiseptic interventions to mitigate the increased risk of PJI after treatment of early PFF.

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.

Causal relationship between cigarette smoking behaviors and the risk of hernias: a Mendelian randomization study

PURPOSE

As the global population continues to age, there is a noticeable yearly rise in the incidence of hernias. Simultaneously, smoking, a widespread addictive behavior and a significant contributor to mortality, has evolved into a pervasive public health concern. Existing literature has already established a connection between smoking and an increased risk of postoperative recurrence and postoperative infections following hernia surgery. However, there remains a dearth of research exploring the association between smoking and hernia morbidity. In this study, our objective is to systematically evaluate the causal relationship between cigarette smoking behaviors and hernia morbidity using a Mendelian randomization (MR) approach.

METHODS

Hernia-related data were sourced from the FinnGen Biobank database, while cigarette smoking behavior data were gathered from the GWAS and Sequencing Consortium of Alcohol and Nicotine Use. To assess the causal relationship, we employed five methods: the weighted median, the weighted mode the inverse variance weighted (IVW), MR-Egger, and the simple mode. Sensitivity analysis was conducted, incorporating Cochran's Q test, the MR-Egger intercept test, leave-one-out analysis, and funnel plot. The presentation of the causal relationship is expressed as an odds ratio (OR) along with their corresponding 95% confidence intervals (CI).

RESULTS

Employing the IVW method as the reference standard, we found that smoking intensity is associated with an increased risk of diaphragmatic hernia (OR = 1.21, 95% CI 1.00-1.46, P = 0.047). These consistent findings were further corroborated by the weighted median and weighted mode methods (OR = 1.26, 95% CI 1.03-1.54, P = 0.026; OR = 1.25, 95% CI 1.02-1.52, P = 0.045). Conversely, when applying the IVW method, we identified no statistically significant causal relationship between smoking age, smoking initiation status, smoking cessation status, and the incidence of hernia.

CONCLUSIONS

Our MR study has uncovered genetic evidence linking smoking intensity and the occurrence of diaphragmatic hernia. The risk of developing diaphragmatic hernia rises in tandem with the intensity of smoking. This emphasizes the crucial role of regularly advising patients to cease smoking in clinical settings.

Oxygen Therapy to Enhance Wound Healing After Revascularization

Oxygen is one of the important factors for wound healing and infection control. The revascularization procedure is amended to correct the tissue hypoxia problem by increasing the blood flow to obtain an adequate amount of oxygen. Hypoxic wounds are still the issue in the cases of unsuccessful or incomplete revascularization. The issue needs to be clarified and confirmed by proper methods for management to achieve wound healing and prevent limb loss. Oxygen therapy may benefit in the case of remaining hypoxia or wound infection in postrevascularization.

Role of Oxygen and Its Radicals in Peripheral Nerve Regeneration: From Hypoxia to Physoxia to Hyperoxia

Oxygen is compulsory for mitochondrial function and energy supply, but it has numerous more nuanced roles. The different roles of oxygen in peripheral nerve regeneration range from energy supply, inflammation, phagocytosis, and oxidative cell destruction in the context of reperfusion injury to crucial redox signaling cascades that are necessary for effective axonal outgrowth. A fine balance between reactive oxygen species production and antioxidant activity draws the line between physiological and pathological nerve regeneration. There is compelling evidence that redox signaling mediated by the Nox family of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases plays an important role in peripheral nerve regeneration. Further research is needed to better characterize the role of Nox in physiological and pathological circumstances, but the available data suggest that the modulation of Nox activity fosters great therapeutic potential. One of the promising approaches to enhance nerve regeneration by modulating the redox environment is hyperbaric oxygen therapy. In this review, we highlight the influence of various oxygenation states, i.e., hypoxia, physoxia, and hyperoxia, on peripheral nerve repair and regeneration. We summarize the currently available data and knowledge on the effectiveness of using hyperbaric oxygen therapy to treat nerve injuries and discuss future directions.

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.

Risk Factors and Complications in Reduction Mammaplasty: A Systematic Review and Meta-analysis

BACKGROUND

Reduction mammaplasty (RM) has become established as the standard effective method for treating macromastia, but reports on the risk factors that predispose to postoperative complications have been conflicting. This meta-analysis aimed to pool the available data to identify predictors of complications following RM.

METHODS

The PubMed, Web of Science, Embase, and Cochrane databases were screened from inception to 1 Jan 2022, and studies were included based on predefined criteria. The perioperative risk factors BMI, smoking, age, diabetes, radiation therapy, and tissue resection weight were extracted and their correlation with complications assessed.

RESULTS

A total of 40 studies comprising of 5908 patients were included. BMI ≥ 30kg/m2 (OR = 1.65, 95% CI 1.35-2.02; p < 0.01) and ≥ 40 kg/m2 (OR = 1.97, 95% CI 1.26-3.08; p < 0.01), smoking (OR = 2.57, 95% CI 2.01-3.28; p < 0.01), diabetes (OR = 2.21, 95% CI 1.19-4.07; p < 0.05), a unilateral resection weight ≥ 1000 g (OR = 1.76, 95% CI 1.02-3.05; p < 0.05), and radiation therapy (OR = 11.11, 95% CI 2.01-3.28; p < 0.01) were associated with higher rates of postoperative complications. Obese patients (BMI ≥ 30 kg/m2) were more likely to experience fat necrosis (OR = 3.00, 95% CI 1.37-6.57; p < 0.01) and infection (OR = 1.66, 95% CI 1.15-2.40; p < 0.05). Smokers had a 2.03 times higher risk of infection (95% CI 1.24-3.31; p < 0.01) and 2.34 times higher risk of dehiscence (95% CI 1.38-3.98; p < 0.01). No association between complication occurrence and age 40 or 50 years or total tissue resection weight ≥ 1000 g was identified.

CONCLUSIONS

This meta-analysis provides evidence that obesity, smoking, diabetes, unilateral resection weight ≥ 1000 g, and preoperative radiation therapy predispose to complication occurrence in RM. This information can optimize the ability of surgeons to provide preoperative patient education, perioperative assessment, and postoperative care planning.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Consenso de expertos sobre la eficacia clínica y directrices sobre la terapia de oxígeno transdérmico continuo para la cicatrización de las heridas complejas o difíciles de cicatrizar

INTRODUCTION

Oxygen is pivotal for wound healing. Its lack or hypoxia can delay this process, especially in individuals with comorbidities, potentially resulting in complex or hard-to-heal wounds. The Colombian Association of Diabetes (ACD) and the Colombian Association of Internal Medicine (ACMI) collaborated with a diverse group of experts to provide recommendations on the efficacy and best practices of continuous transdermal oxygen therapy (TOTc) in the care of such wounds.

METHOD

A modified Delphi technique was employed to obtain controlled feedback and responses. Experts from various disciplines engaged in reviewing and discussing numerous relevant scientific studies, focusing on the role of TOTc in treating chronic ulcers.

RESULTS

Continuous transdermal oxygen therapy has proven to be an effective and safe treatment for chronic and/or hard-to-heal ulcers. This therapy directly addresses the wound's oxygen deficiency, providing an environment conducive to healing. Significant benefits were observed, including the acceleration of the healing process, wound size reduction, and an enhancement in patient quality of life. Its efficacy was found across various ulcer etiologies, underscoring its therapeutic versatility.

CONCLUSIONS

Continuous transdermal oxygen therapy is effective and safe for treating chronic and hard-to-heal ulcers. It's crucial to address each case individually and through a multidisciplinary approach to maximize this therapy's benefits. Both evidence and clinical experience back its utility across a variety of ulcer etiologies.

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.

Blood Vessel Injuries of the Fingers: A Clinical Comparison of One- and Two-Arterial Blood Supply

Traumatic finger injuries are very common in emergency medicine. When patients present with finger injuries, there is often damage to the vascular nerve bundles, which requires subsequent reconstruction. It is unknown if repairing a unilaterally injured artery affects patients' recovery in a well-perfused finger. This retrospective cohort study compares the clinical outcomes of 11 patients with one-vessel supply (mean age 48.3 years; 7 males, 4 females) to 14 patients with two-vessel supply (mean age 44.5 years; 8 males, 6 females). The patient outcomes were assessed using patient questionnaires (Disabilities of Arm, Shoulder, and Hand (DASH), European Quality of Life 5 Dimensions 5 Level Version (EQ-5D-5L), and EuroQol visual analog scale (EQ-VAS)) and a clinical examination of hand function and imaging of circulatory efficiency. No significant changes were observed in the DASH, EQ-5D-5L, and EQ-VAS questionnaires. Clinical evaluation of hand function, measured by cold sensitivity, two-point discrimination, pain numerical analog scale, and grip strength also revealed no significant differences between cohorts. Blood flow measurements using thermal imaging revealed no effects on circulation in the affected digit. Collectively, the study finds reconstruction is not absolutely necessary when there is one intact digital artery as it is sufficient for healing and functional outcomes. We recommend finger artery reconstruction when both digital arteries are injured or if an immediate tension-free suture is possible.

Oxygenated Wound Dressings for Hypoxia Mitigation and Enhanced Wound Healing

Oxygen is a critical factor that can regulate the wound healing processes such as skin cell proliferation, granulation, re-epithelialization, angiogenesis, and tissue regeneration. However, hypoxia, a common occurrence in the wound bed, can impede normal healing processes. To enhance wound healing, oxygenation strategies that could effectively increase wound oxygen levels are effective. The present review summarizes wound healing stages and the role of hypoxia in wound healing and overviews current strategies to incorporate various oxygen delivery or generating materials for wound dressing, including catalase, nanoenzyme, hemoglobin, calcium peroxide, or perfluorocarbon-based materials, in addition to photosynthetic bacteria and hyperbaric oxygen therapy. Mechanism of action, oxygenation efficacy, and potential benefits and drawbacks of these dressings are also discussed. We conclude by highlighting the importance of design optimization in wound dressings to address the clinical needs to improve clinical outcomes.

Oxygen-releasing biomaterials for chronic wounds breathing: From theoretical mechanism to application prospect

Chronic wounds have always been considered as "gordian knots" in medicine, in which hypoxia plays a key role in blocking healing. To address this challenge, although tissue reoxygenation therapy based on hyperbaric oxygen therapy (HBOT) has been performed clinically for several years, the bench to bedside still urges the evolution of oxygen-loading and -releasing strategies with explicit benefits and consistent outcome. The combination of various oxygen carriers with biomaterials has gained momentum as an emerging therapeutic strategy in this field, exhibiting considerable application potential. This review gives an overview of the essential relationship between hypoxia and delayed wound healing. Further, detailed characteristics, preparation methods and applications of various oxygen-releasing biomaterials (ORBMs) will be elaborated, including hemoglobin, perfluorocarbon, peroxide, and oxygen-generating microorganisms, those biomaterials are applied to load, release or generate a vast of oxygen to relieve the hypoxemia and bring the subsequent cascade effect. The pioneering papers regarding to the ORBMs practice are presented and trends toward hybrid and more precise manipulation are summarized.

Protocol and statistical analysis plan for the mega randomised registry trial comparing conservative vs. liberal oxygenation targets in adults with sepsis in the intensive care unit (Mega-ROX Sepsis)

Background

The effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults with sepsis receiving unplanned invasive mechanical ventilation in the intensive care unit (ICU) is uncertain.

Objective

The objective of this study was to summarise the protocol and statistical analysis plan for the Mega-ROX Sepsis trial.

Design setting and participants

The Mega-ROX Sepsis trial is an international randomised clinical trial that will be conducted within an overarching 40,000-patient registry-embedded clinical trial comparing conservative and liberal ICU oxygen therapy regimens. We anticipate that between 10,000 and 13,000 patients with sepsis who are receiving unplanned invasive mechanical ventilation in the ICU will be enrolled in this trial.

Main outcome measures

The primary outcome is in-hospital all-cause mortality up to 90 days from the date of randomisation. Secondary outcomes include duration of survival, duration of mechanical ventilation, ICU length of stay, hospital length of stay, and the proportion of patients discharged home.

Results and conclusions

Mega-ROX Sepsis will compare the effect of conservative vs. liberal oxygen therapy on 90-day in-hospital mortality in adults with sepsis who are receiving unplanned invasive mechanical ventilation in the ICU. The protocol and a prespecified approach to analyses are reported here to mitigate analysis bias.

[Perioperative hyperoxia-More harmful than beneficial?]

BACKGROUND

The ideal perioperative oxygen concentration is controversial and study results are inconsistent.

OBJECTIVE

Current knowledge on the beneficial and adverse effects of perioperative hyperoxia.

MATERIAL AND METHODS

Narrative review RESULTS: Perioperative hyperoxia is unlikely to increase the incidence of atelectasis, pulmonary or cardiovascular complications or mortality. Few and small potential beneficial effects, such as reduction of surgical wound infections or postoperative nausea and vomiting have been demonstrated. According to the current state of evidence, it is recommended to avoid perioperative hyperoxia and to aim for normoxia instead.

Use of closed incision negative pressure wound therapy on C-section wounds in obese women

Rates of obesity in pregnant women are increasing. Obesity is linked to increased patient risk of developing postoperative wound complications such as surgical site infection, wound dehiscence and haematoma formation. Closed incision negative pressure wound therapy (ciNPWT) has been introduced as a prophylactic intervention to reduce caesarian section (C-section) wound complications. Evidence from randomised controlled trials and retrospective studies has shown variable rates of success in reducing risk of SSI. The studies reviewed in this article found that ciNPWT had no statistically significant impact in reducing rates of wound dehiscence and haematoma formation or increasing long-term satisfaction with the appearance of scar tissue following C-section. Further research into the use of cINPWT to prevent surgical site infection is needed to determine the effectiveness of this therapy in reducing this wound complication.

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.

Role of Iron Oxide (Fe2O3) Nanocomposites in Advanced Biomedical Applications: A State-of-the-Art Review

Nanomaterials have demonstrated a wide range of applications and recently, novel biomedical studies are devoted to improving the functionality and effectivity of traditional and unmodified systems, either drug carriers and common scaffolds for tissue engineering or advanced hydrogels for wound healing purposes. In this regard, metal oxide nanoparticles show great potential as versatile tools in biomedical science. In particular, iron oxide nanoparticles with different shape and sizes hold outstanding physiochemical characteristics, such as high specific area and porous structure that make them idoneous nanomaterials to be used in diverse aspects of medicine and biological systems. Moreover, due to the high thermal stability and mechanical strength of Fe₂O₃, they have been combined with several polymers and employed for various nano-treatments for specific human diseases. This review is focused on summarizing the applications of Fe₂O₃-based nanocomposites in the biomedical field, including nanocarriers for drug delivery, tissue engineering, and wound healing. Additionally, their structure, magnetic properties, biocompatibility, and toxicity will be discussed.

Free-standing multilayer films as growth factor reservoirs for future wound dressing applications

Chronic skin wounds place a high burden on patients and health care systems. The use of angiogenic and mitogenic growth factors can facilitate the healing but growth factors are quickly inactivated by the wound environment if added exogenously. Here, free-standing multilayer films (FSF) are fabricated from chitosan and alginate as opposing polyelectrolytes in an alternating manner using layer-by-layer technique. One hundred bilayers form an about 450 μm thick, detachable free-standing film that is subsequently crosslinked by either ethyl (dimethylaminopropyl) carbodiimide combined with N-hydroxysuccinimide (E-FSF) or genipin (G-FSF). The characterization of swelling, oxygen permeability and crosslinking density shows reduced swelling and oxygen permeability for both crosslinked films compared to non-crosslinked films (N-FSF). Loading of fibroblast growth factor 2 (FGF2) into the films results in a sustained release from crosslinked FSF in comparison to non-crosslinked FSF. Biocompatibility studies in vitro with human dermal fibroblasts cultured underneath the films demonstrate increased cell growth and cell migration for all films with and without FGF2. Especially G-FSF loaded with FGF2 greatly increases cell proliferation and migration. In vivo biocompatibility studies by subcutaneous implantation in mice show that E-FSF causes an inflammatory tissue response that is absent in the case of G-FSF. N-FSF also represents a biocompatible film but shows early degradation. All FSF possess antibacterial properties against gram+ and gram- bacteria demonstrated by an agar diffusion disc assay. In summary, FSF made of alginate and chitosan crosslinked with genipin can act as a reservoir for the sustained release of FGF2, possessing high biocompatibility in vitro and in vivo. Moreover, G-FSF promotes growth and migration of human dermal fibroblasts and has antibacterial properties, which makes it an interesting candidate for bioactive wound.

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.

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.

Smoking increases the risk of postoperative wound complications: A propensity score-matched cohort study

Cigarette smoking is associated with surgical complications, including wound healing and surgical site infection. However, the association between smoking status and postoperative wound complications is not completely understood. Our objective was to investigate the effect of smoking on postoperative wound complications for major surgeries. Data were collected from the 2013 to 2018 participant use files of the American College of Surgeons National Surgical Quality Improvement Program database. A propensity score matching procedure was used to create the balanced smoker and nonsmoker groups. Multivariable logistic regression was used to calculate the odds ratios (ORs) with 95% confidence intervals (CIs) for postoperative wound complications, pulmonary complications, and in-hospital mortality associated with smokers. A total of 1 156 002 patients (578 001 smokers and 578 001 nonsmokers) were included in the propensity score matching analysis. Smoking was associated with a significantly increased risk of postoperative wound disruption (OR 1.65, 95% CI 1.56-1.75), surgical site infection (OR 1.31, 95% CI 1.28-1.34), reintubation (OR 1.47, 95% CI 1.40-1.54), and in-hospital mortality (OR 1.13, 95% CI 1.07-1.19) compared with nonsmoking. The length of hospital stay was significantly increased in smokers compared with nonsmokers. Our analysis indicates that smoking is associated with an increased risk of surgical site infection, wound disruption, and postoperative pulmonary complications. The results may drive the clinicians to encourage patients to quit smoking before surgery.

Prevention of Surgical Site Infections in Neonates and Children: Non-Pharmacological Measures of Prevention

A surgical site infection (SSI) is an infection that occurs in the incision created by an invasive surgical procedure. Although most infections are treatable with antibiotics, SSIs remain a significant cause of morbidity and mortality after surgery and have a significant economic impact on health systems. Preventive measures are essential to decrease the incidence of SSIs and antibiotic abuse, but data in the literature regarding risk factors for SSIs in the pediatric age group are scarce, and current guidelines for the prevention of the risk of developing SSIs are mainly focused on the adult population. This document describes the current knowledge on risk factors for SSIs in neonates and children undergoing surgery and has the purpose of providing guidance to health care professionals for the prevention of SSIs in this population. Our aim is to consider the possible non-pharmacological measures that can be adopted to prevent SSIs. To our knowledge, this is the first study to provide recommendations based on a careful review of the available scientific evidence for the non-pharmacological prevention of SSIs in neonates and children. The specific scenarios developed are intended to guide the healthcare professional in practice to ensure standardized management of the neonatal and pediatric patients, decrease the incidence of SSIs and reduce antibiotic abuse.

Novel Technologies in Chronic Wound Care

In Israel, 20% of wounds do not progress to full healing under treatment with conservative technologies of which 1 to 2% are eventually defined as chronic wounds. Chronic wounds are a complex health burden for patients and pose considerable therapeutic and budgetary burden on health systems. The causes of chronic wounds include systemic and local factors. Initial treatment involves the usual therapeutic means, but as healing does not progress, more advanced therapeutic technologies are used. Undoubtedly, advanced means, such as negative pressure systems, and advanced technologies, such as oxygen systems and micrografts, have vastly improved the treatment of chronic wounds. Our service specializes in treating ulcers and difficult-to-heal wounds while providing a multiprofessional medical response. Herein, we present our experience and protocols in treating chronic wounds using a variety of advanced dressings and technologies.

Aggressive intraoperative warming versus routine thermal management during non-cardiac surgery (PROTECT): a multicentre, parallel group, superiority trial

BACKGROUND

Moderate intraoperative hypothermia promotes myocardial injury, surgical site infections, and blood loss. Whether aggressive warming to a truly normothermic temperature near 37°C improves outcomes remains unknown. We aimed to test the hypothesis that aggressive intraoperative warming reduces major perioperative complications.

METHODS

In this multicentre, parallel group, superiority trial, patients at 12 sites in China and at the Cleveland Clinic in the USA were randomly assigned (1:1) to receive either aggressive warming to a target core temperature of 37°C (aggressively warmed group) or routine thermal management to a target of 35·5°C (routine thermal management group) during non-cardiac surgery. Randomisation was stratified by site, with computer-generated, randomly sized blocks. Eligible patients (aged ≥45 years) had at least one cardiovascular risk factor, were scheduled for inpatient non-cardiac surgery expected to last 2-6 h with general anaesthesia, and were expected to have at least half of the anterior skin surface available for warming. Patients requiring dialysis and those with a body-mass index exceeding 30 kg/m² were excluded. The primary outcome was a composite of myocardial injury (troponin elevation, apparently of ischaemic origin), non-fatal cardiac arrest, and all-cause mortality within 30 days of surgery, as assessed in the modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03111875.

FINDINGS

Between March 27, 2017, and March 16, 2021, 5056 participants were enrolled, of whom 5013 were included in the intention-to-treat population (2507 in the aggressively warmed group and 2506 in the routine thermal management group). Patients assigned to aggressive warming had a mean final intraoperative core temperature of 37·1°C (SD 0·3) whereas the routine thermal management group averaged 35·6°C (SD 0·3). At least one of the primary outcome components (myocardial injury after non-cardiac surgery, cardiac arrest, or mortality) occurred in 246 (9·9%) of 2497 patients in the aggressively warmed group and in 239 (9·6%) of 2490 patients in the routine thermal management group. The common effect relative risk of aggressive versus routine thermal management was an estimated 1·04 (95% CI 0·87-1·24, p=0·69). There were 39 adverse events in patients assigned to aggressive warming (17 of which were serious) and 54 in those assigned to routine thermal management (30 of which were serious). One serious adverse event, in an aggressively warmed patient, was deemed to be possibly related to thermal management.

INTERPRETATION

The incidence of a 30-day composite of major cardiovascular outcomes did not differ significantly in patients randomised to 35·5°C and to 37°C. At least over a 1·5°C range from very mild hypothermia to full normothermia, there was no evidence that any substantive outcome varied. Keeping core temperature at least 35·5°C in surgical patients appears sufficient.

FUNDING

3M and the Health and Medical Research Fund, Food and Health Bureau, Hong Kong.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Hyperoxia and Acute Kidney Injury: A Tale of Oxygen and the Kidney

Although oxygen supplementation is beneficial to support life in the clinic, excessive oxygen therapy also has been linked to damage to organs such as the lung or the eye. However, there is a lack of understanding of whether high oxygen therapy directly affects the kidney, leading to acute kidney injury, and what molecular mechanisms may be involved in this process. In this review, we revise our current understanding of the mechanisms by which hyperoxia leads to organ damage and highlight possible areas of investigation for the scientific community interested in novel mechanisms of kidney disease. Overall, we found a significant need for both animal and clinical studies evaluating the role of hyperoxia in inducing kidney damage. Thus, we urge the research community to further investigate oxygen therapy and its impact on kidney health with the goal of optimizing oxygen therapy guidelines and improving patient care.

Incidence and predictors of surgical site infection in women who are obese and give birth by elective caesarean section: A secondary analysis

BACKGROUND

Surgical site infection (SSI) after a caesarean section is of concern (CS) is of concern to both clinicians and women themselves.

AIMS

The aim of this study is to identify the cumulative incidence and predictors of SSI in women who are obese and give birth by elective CS.

MATERIALS AND METHODS

The method used was planned secondary analysis of data from women with a pre-pregnancy body mass index (BMI) ≥30 kg/m2 giving birth by elective CS in a multicentre randomised controlled trial of a prophylactic closed-incision negative pressure wound therapy dressing. Data were collected from medical records, direct observations of the surgical site and self-reported signs and symptoms from October 2015 to December 2019. The Centers for Disease Control and Prevention definition was used to identify SSI. Women were followed up once in hospital just before discharge and then weekly for four weeks after discharge. Blinded outcome assessors determined SSI. After the cumulative incidence of SSI was calculated, multiple variable logistic regression models were used to identify independent risk factors for SSI.

RESULTS

SSI incidence in 1459 women was 8.4% (122/1459). Multiple variable-adjusted odds ratios (OR) for SSI were BMI ≥40 kg/m2 (OR 1.55, 95% confidence interval (CI) 1.30-1.86) as compared to BMI 30-34.9 0 kg/m2 , ≥2 previous pregnancies (OR 1.38, 95% CI 1.00-1.80) as compared to no previous pregnancies and pre-CS vaginal cleansing (OR 0.55, 95% CI 0.33-0.99).

CONCLUSIONS

Our findings may inform preoperative counselling and shared decision-making regarding planned elective CS for women with pre-pregnancy BMI ≥30 kg/m2 .

Nanomaterials for the delivery of bioactive factors to enhance angiogenesis of dermal substitutes during wound healing

Dermal substitutes provide a template for dermal regeneration and reconstruction. They constitutes an ideal clinical treatment for deep skin defects. However, rapid vascularization remains as a major hurdle to the development and application of dermal substitutes. Several bioactive factors play an important regulatory role in the process of angiogenesis and an understanding of the mechanism of achieving their effective delivery and sustained function is vital. Nanomaterials have great potential for tissue engineering. Effective delivery of bioactive factors (including growth factors, peptides and nucleic acids) by nanomaterials is of increasing research interest. This paper discusses the process of dermal substitute angiogenesis and the roles of related bioactive factors in this process. The application of nanomaterials for the delivery of bioactive factors to enhance angiogenesis and accelerate wound healing is also reviewed. We focus on new systems and approaches for delivering bioactive factors for enhancing angiogenesis in dermal substitutes.

Early aseptic reoperation after shoulder arthroplasty increases risk of subsequent prosthetic joint infection

Background

Despite the success of anatomic total shoulder arthroplasty (TSA) and reverse shoulder arthroplasty (RSA), the clinical course of some patients necessitates operative intervention in the acute postoperative period. In this study, we evaluate the risk of subsequent prosthetic joint infection (PJI) in patients who undergo an aseptic reoperation within 90 days of primary shoulder arthroplasty.

Method

A retrospective review of patients with primary TSA and RSA was performed using a commercially available national database (PearlDiver Inc., Fort Wayne, IN, USA). Queries were performed with use of International Classification of Diseases, Ninth Revision and Tenth Revision and Current Procedural Technology codes. Patients were divided into cohorts based on undergoing aseptic reoperation, reoperation for PJI, or no reoperations within 90 days of index procedure. Primary outcome was subsequent PJI within 1 year of index procedure. Observed PJI rates were compared using chi-square analysis. Risk factors for PJI were compared using logistic regression.

Results

From 2010 to 2018, a total of 96,648 patients underwent primary shoulder arthroplasty: 46,810 underwent TSA and 49,838 underwent RSA. The rate of aseptic reoperation within 90 days was 0.72% and 1.5% in the TSA and RSA cohorts, respectively. At 1 year postoperatively, patients who underwent an aseptic reoperation within 90 days had an elevated risk of subsequent PJI compared with the overall rate of PJI in the TSA (3.54% vs. 0.75%; P < .001) and RSA (3.08% vs. 0.73%; P < .001) cohorts. On multivariate logistic regression analysis, aseptic reoperation within 90 days was identified as a significant risk factor for subsequent PJI in the TSA cohort (odds ratio, 14.19; P < .001) and RSA cohort (odds ratio, 8.38; P < .001). The most common indication for aseptic reoperation was postoperative prosthetic joint instability in both the TSA (31%) and RSA (49%) cohorts.

Conclusion

Aseptic reoperation within 90 days of primary TSA or primary RSA was associated with a notably increased risk of subsequent PJI.

Incisional negative pressure wound therapy for clean-contaminated wounds in abdominal surgery: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The role of incisional negative-pressure wound therapy (iNPWT) in preventing surgical site infections (SSIs) in clean-contaminated abdominal wounds is still controversial. This meta-analysis was performed to evaluate whether the use of iNPWT could reduce SSIs and other complications in clean-contaminated abdominal surgery.

METHODS

The authors searched PubMed, EMBASE, Cochrane library, and Web of Science from database inception to 23 January 2021 for randomized controlled trials (RCTs). They assessed the risk of bias using the Cochrane Collaboration risk of bias tool and conducted a meta-analysis using RevMan 5.4.

RESULTS

Eleven RCTs, including 4112 patients, were analyzed, of which 2057 were treated with iNPWT and 2055 with standard dressings. The SSI rates (OR = 0.76, 95% CI = 0.61-0.94, P = 0.01), in patients undergoing an iNPWT intervention were significantly lower than those in patients receiving standard dressings. There was no statistically significant difference between the rates of incision dehiscence, seroma, and readmission between groups.

CONCLUSIONS

Application of iNPWT for clean-contaminated wounds in abdominal surgery reduced SSI rates but showed similar rates of wound dehiscence, seroma, and readmission compared with standard dressings.

Oxygen, pH, Lactate, and Metabolism-How Old Knowledge and New Insights Might Be Combined for New Wound Treatment

Over time, we have come to recognize a very complex network of physiological changes enabling wound healing. An immunological process enables the body to distinguish damaged cells and begin a cleaning mechanism by separating damaged proteins and cells with matrix metalloproteinases, a complement reaction, and free radicals. A wide variety of cell functions help to rebuild new tissue, dependent on energy provision and oxygen supply. Like in an optimized “bio-reactor,” disturbance can lead to prolonged healing. One of the earliest investigated local factors is the pH of wounds, studied in close relation to the local perfusion, oxygen tension, and lactate concentration. Granulation tissue with the wrong pH can hinder fibroblast and keratinocyte division and proliferation, as well as skin graft takes. Methods for influencing the pH have been tested, such as occlusion and acidification by the topical application of acidic media. In most trials, this has not changed the wound’s pH to an acidic one, but it has reduced the strong alkalinity of deeper or chronic wounds. Energy provision is essential for all repair processes. New insights into the metabolism of cells have changed the definition of lactate from a waste product to an indispensable energy provider in normoxic and hypoxic conditions. Neovascularization depends on oxygen provision and lactate, signaling hypoxic conditions even under normoxic conditions. An appropriate pH is necessary for successful skin grafting; hypoxia can change the pH of wounds. This review describes the close interconnections between the local lactate levels, metabolism, healing mechanisms, and pH. Furthermore, it analyzes and evaluates the different possible ways to support metabolism, such as lactate enhancement and pH adjustment. The aim of wound treatment must be the optimization of all these components. Therefore, the role of lactate and its influence on wound healing in acute and chronic wounds will be assessed.

Oxygenated Nanocellulose-A Material Platform for Antibacterial Wound Dressing Devices

Both carboxylated cellulose nanofibrils (CNF) and dissolved oxygen (DO) have been reported to possess antibacterial properties. However, the combination for use as wound dressings against biofilm infections in chronic wounds is less known. The present study reports the development of oxygenated CNF dispersions that exhibit strong antibacterial effect. Carboxylated CNF dispersions with different oxidation levels were oxygenated by the OXY BIO System and tested for antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus. The results reveal that the higher oxidation level of the CNFs, the better antibacterial effect. Scanning electron microscopy of bacterial biofilms revealed that a potential mechanism of action of the CNFs is the formation of a network surrounding and entrapping the bacteria. This effect is further potentiated by the oxygenation process. A CNF sample (concentration 0.6 wt %) that was oxygenated to a DO level of 46.4 mg/L demonstrated a strong antibacterial effect against S. aureus in vivo using a mouse model of surgical site infection. The oxygenated CNF dispersion reduced the bacterial survival by 71%, after 24 h treatment. The potent antibacterial effect indicates that oxygenated nanocellulose is a promising material for antibacterial wound dressings.

Dissolved oxygen technologies as a novel strategy for non-healing wounds: A critical review

Non-healing wounds are steadily becoming a global-health issue. Prolonged hypoxia propagates wound chronicity; yet, oxygenating treatments are considered inadequate to date. Dissolved oxygen (DO) in aqueous solutions introduces a novel approach to enhanced wound oxygenation, and is robustly evaluated for clinical applications. A systematic literature search was conducted, whereby experimental and clinical studies of DO technologies were categorized per engineering approach. Technical principles, methodology, endpoints and outcomes were analysed for both oxygenating and healing effects. Forty articles meeting our inclusion criteria were grouped as follows: DO solutions (17), oxygen (O₂ ) dressings (9), O₂ hydrogels (11) and O₂ emulsions (3). All technologies improved wound oxygenation, each to a variable degree. They also achieved at least one statistically significant outcome related to wound healing, mainly in epithelialization, angiogenesis and collagen synthesis. Scarcity in clinical data and methodological variability precluded quantitative comparisons among the biotechnologies studied. DO technologies warrantee further evaluation for wound oxygenation in the clinical setting. Standardised methodologies and targeted research questions are pivotal to facilitate global integration in healthcare.