Benefits and harms of perioperative high fraction inspired oxygen for surgical site infection prevention: a protocol for a systematic review and meta-analysis of individual patient data of randomised controlled trials.

INTRODUCTION: The use of high fraction of inspired oxygen (FiO2) intraoperatively for the prevention of surgical site infection (SSI) remains controversial. Promising results of early randomised controlled trials (RCT) have been replicated with varying success and subsequent meta-analysis are equivocal. Recent advancements in perioperative care, including the increased use of laparoscopic surgery and pneumoperitoneum and shifts in fluid and temperature management, can affect peripheral oxygen delivery and may explain the inconsistency in reproducibility. However, the published data provides insufficient detail on the participant level to test these hypotheses. The purpose of this individual participant data meta-analysis is to assess the described benefits and harms of intraoperative high FiO2compared with regular (0.21-0.40) FiO2 and its potential effect modifiers. METHODS AND ANALYSIS: Two reviewers will search medical databases and online trial registries, including MEDLINE, Embase, CENTRAL, CINAHL, ClinicalTrials.gov and WHO regional databases, for randomised and quasi-RCT comparing the effect of intraoperative high FiO2 (0.60-1.00) to regular FiO2 (0.21-0.40) on SSI within 90 days after surgery in adult patients. Secondary outcome will be all-cause mortality within the longest available follow-up. Investigators of the identified trials will be invited to collaborate. Data will be analysed with the one-step approach using the generalised linear mixed model framework and the statistical model appropriate for the type of outcome being analysed (logistic and cox regression, respectively), with a random treatment effect term to account for the clustering of patients within studies. The bias will be assessed using the Cochrane risk-of-bias tool for randomised trials V.2 and the certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluation methodology. Prespecified subgroup analyses include use of mechanical ventilation, nitrous oxide, preoperative antibiotic prophylaxis, temperature (<35°C), fluid supplementation (<15 mL/kg/hour) and procedure duration (>2.5 hour). ETHICS AND DISSEMINATION: Ethics approval is not required. Investigators will deidentify individual participant data before it is shared. The results will be submitted to a peer-review journal. PROSPERO REGISTRATION NUMBER: CRD42018090261.

Intraoperative Fraction of Inspired Oxygen and Lung Injury in Coronary Artery Bypass Grafting: Study Protocol for a Randomised Controlled Trial.

OBJECTIVE: Postoperative pulmonary complications are a series of disorders that can contribute to respiratory distress and prolonged mechanical ventilation postoperatively. We hypothesise that a liberal oxygenation strategy during cardiac surgery leads to a higher incidence of postoperative pulmonary complications than a restrictive oxygenation strategy. METHODS: This study is a prospective, observer-blinded, centrally randomised and controlled, international multicentre clinical trial. RESULTS: After obtaining a written informed consent, 200 adult patients undergoing coronary artery bypass grafting will be enrolled and randomised to receive either restrictive or liberal oxygenation perioperatively. The liberal oxygenation group will receive 1.0 fraction of inspired oxygen throughout the intraoperative period, including during cardiopulmonary bypass. The restrictive oxygenation group will receive the lowest fraction of inspired oxygen required to maintain arterial partial pressure of oxygen between 100 and 150 mmHg during cardiopulmonary bypass and a pulse oximetry reading of 95% or greater intraoperatively, but no less than 0.3 and not higher than 0.80 (other than induction and when the oxygenation goals cannot be reached). When patients are transferred to the intensive care unit, all patients will receive an initial fraction of inspired oxygen of 0.5, and then fraction of inspired oxygen will be titrated to maintain a pulse oximetry reading of 95% or greater until extubation. The lowest postoperative arterial partial pressure of oxygen/fraction of inspired oxygen within 48 hours of intensive care unit admission will be the primary outcome. Postoperative pulmonary complications, length of mechanical ventilation, intensive care unit stay, hospital stay, and 7-day mortality after cardiac surgery will be analysed as secondary outcomes. CONCLUSION: This is one of the first randomised controlled observer-blinded trials that prospectively evaluates the influence of higher inspired oxygen fractions on early postoperative respiratory and oxygenation outcomes in cardiac surgery patients using cardiopulmonary bypass.

Outcomes and Risk Factors for Cardiovascular Events in Hospitalized COVID-19 Patients.

OBJECTIVE: To analyze outcomes and risk factors of cardiovascular events in a metropolitan coronavirus disease 2019 (COVID-19) database, and to perform a subgroup analysis in African American populations to determine whether outcomes and risk factors are influenced by race. DESIGN: Retrospective cohort analysis from March 9, 2020 to June 20, 2020. SETTING: Population-based study in Louisville, KY, USA. PARTICIPANTS: Seven hundred adult inpatients hospitalized with COVID-19. INTERVENTIONS: N/A. MEASUREMENTS AND MAIN RESULTS: This cohort consisted of 126 patients (18%) with cardiovascular events and 574 patients without cardiovascular events. Patients with cardiovascular events had a much higher mortality rate than those without cardiovascular events (45.2% v 8.7%, p < 0.001). There was no difference between African American and white patients regarding mortality (43.9% v 46.3%, p = 1) and length of stay for survivors (11 days v 9.5 days, p = 0.301). Multiple logistics regression analysis suggested that male, race, lower SaO2/FIO2, higher serum potassium, lower serum albumin, and number of cardiovascular comorbidities were highly associated with the occurrence of cardiovascular events in COVID-19 patients. Lower serum albumin and neoplastic and/or immune-compromised diseases were highly associated with cardiovascular events for African American COVID-19 patients. SaO2/FIO2 ratio and cardiovascular comorbidity count were significantly associated with cardiovascular events in white patients. CONCLUSIONS: Cardiovascular events were prevalent and associated with worse outcomes in hospitalized patients with COVID-19. Outcomes of cardiovascular events in African American and white COVID-19 patients were similar after propensity score matching analysis. There were common and unique risk factors for cardiovascular events in African American COVID-19 patients when compared with white patients.

Early Prediction of Prognosis in Elderly Acute Stroke Patients.

Acute stroke has a high morbidity and mortality in elderly population. Baseline confounding illnesses, initial clinical examination, and basic laboratory tests may impact prognostics. In this study, we aimed to establish a model for predicting in-hospital mortality based on clinical data available within 12 hours of hospital admission in elderly (≥ 65 age) patients who experienced stroke. DESIGN: Retrospective observational cohort study. SETTING: Academic comprehensive stroke center. PATIENTS: Elderly acute stroke patients-2005-2009 (n = 462), 2010-2012 (n = 122), and 2016-2017 (n = 123). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After institutional review board approval, we retrospectively queried elderly stroke patients' data from 2005 to 2009 (training dataset) to build a model to predict mortality. We designed a multivariable logistic regression model as a function of baseline severity of illness and laboratory tests, developed a nomogram, and applied it to patients from 2010 to 2012. Due to updated guidelines in 2013, we revalidated our model (2016-2017). The final model included stroke type (intracerebral hemorrhage vs ischemic stroke: odds ratio [95% CI] of 0.92 [0.50-1.68] and subarachnoid hemorrhage vs ischemic stroke: 1.0 [0.40-2.49]), year (1.01 [0.66-1.53]), age (1.78 [1.20-2.65] per 10 yr), smoking (8.0 [2.4-26.7]), mean arterial pressure less than 60 mm Hg (3.08 [1.67-5.67]), Glasgow Coma Scale (0.73 [0.66-0.80] per 1 point increment), WBC less than 11 K (0.31 [0.16-0.60]), creatinine (1.76 [1.17-2.64] for 2 vs 1), congestive heart failure (2.49 [1.06-5.82]), and warfarin (2.29 [1.17-4.47]). In summary, age, smoking, congestive heart failure, warfarin use, Glasgow Coma Scale, mean arterial pressure less than 60 mm Hg, admission WBC, and creatinine levels were independently associated with mortality in our training cohort. The model had internal area under the curve of 0.83 (0.79-0.89) after adjustment for over-fitting, indicating excellent discrimination. When applied to the test data from 2010 to 2012, the nomogram accurately predicted mortality with area under the curve of 0.79 (0.71-0.87) and scaled Brier's score of 0.17. Revalidation of the same model in the recent dataset from 2016 to 2017 confirmed accurate prediction with area under the curve of 0.83 (0.75-0.91) and scaled Brier's score of 0.27. CONCLUSIONS: Baseline medical problems, clinical severity, and basic laboratory tests available within the first 12 hours of admission provided strong independent predictors of in-hospital mortality in elderly acute stroke patients. Our nomogram may guide interventions to improve acute care of stroke.

Perioperative Supplemental Oxygen Does Not Worsen Long-Term Mortality of Colorectal Surgery Patients.

BACKGROUND: A follow-up analysis from a large trial of oxygen and surgical-site infections reported increased long-term mortality among patients receiving supplemental oxygen, especially those having cancer surgery. Although concerning, there is no obvious mechanism linking oxygen to long-term mortality. We thus tested the hypothesis that supplemental oxygen does not increase long-term mortality in patients undergoing colorectal surgery. Secondarily, we evaluated whether the effect of supplemental oxygen on mortality depended on cancer status. METHODS: Mortality data were obtained for 927 patients who participated in 2 randomized trials evaluating the effect of supplemental oxygen on wound infection. We assessed the effect of 80% vs 30% oxygen on long-term mortality across 4 clinical sites in the 2 trials using a Cox proportional hazards regression model stratified by study and site. Kaplan-Meier survival estimates were calculated for each trial. Finally, we report site-stratified hazard ratios for patients with and without cancer at baseline. RESULTS: There was no effect of 80% vs 30% oxygen on mortality, with an overall site-stratified hazard ratio of 0.93 (95% confidence interval [CI], 0.72-1.20; P = 0.57). The treatment effect was consistent across the 2 original studies (interaction P = 0.88) and across the 4 sites (P = 0.84). There was no difference between patients with (n = 451) and without (n = 450) cancer (interaction P = 0.51), with hazard ratio of 0.85 (95% CI, 0.64-1.1) for cancer patients and 0.97 (0.53-1.8) for noncancer patients. CONCLUSIONS: In contrast to the only previous publication, we found that supplemental oxygen had no influence on long-term mortality in the overall surgical population or in patients having cancer surgery.

Teaching basic lung isolation skills on human anatomy simulator: attainment and retention of lung isolation skills.

BACKGROUND: Lung isolation skills, such as correct insertion of double lumen endobronchial tube and bronchial blocker, are essential in anesthesia training; however, how to teach novices these skills is underexplored. Our aims were to determine (1) if novices can be trained to a basic proficiency level of lung isolation skills, (2) whether video-didactic and simulation-based trainings are comparable in teaching lung isolation basic skills, and (3) whether novice learners' lung isolation skills decay over time without practice. METHODS: First, five board certified anesthesiologist with experience of more than 100 successful lung isolations were tested on Human Airway Anatomy Simulator (HAAS) to establish Expert proficiency skill level. Thirty senior medical students, who were naive to bronchoscopy and lung isolation techniques (Novice) were randomized to video-didactic and simulation-based trainings to learn lung isolation skills. Before and after training, Novices' performances were scored for correct placement using pass/fail scoring and a 5-point Global Rating Scale (GRS); and time of insertion was recorded. Fourteen novices were retested 2 months later to assess skill decay. RESULTS: Experts' and novices' double lumen endobronchial tube and bronchial blocker passing rates showed similar success rates after training (P >0.99). There were no differences between the video-didactic and simulation-based methods. Novices' time of insertion decayed within 2 months without practice. CONCLUSION: Novices could be trained to basic skill proficiency level of lung isolation. Video-didactic and simulation-based methods we utilized were found equally successful in training novices for lung isolation skills. Acquired skills partially decayed without practice.

Teaching basic fiberoptic intubation skills in a simulator: initial learning and skills decay.

PURPOSE: Generally, novices are taught fiberoptic intubation on patients by attending anesthesiologists; however, this approach raises patient safety concerns. Patient safety should improve if novice learners are trained for basic skills on simulators. In this educational study, we assessed the time and number of attempts required to train novices in fiberoptic bronchoscopy and fiberoptic intubation on simulators. Because decay in skills is inevitable, we also assessed fiberoptic bronchoscopy and fiberoptic intubation skill decay and the amount of effort required to regain fiberoptic bronchoscopy skill. METHODS: First, we established attempt- and duration-based quantitative norms for reaching skill proficiency for fiberoptic bronchoscopy and fiberoptic intubation by experienced anesthesiologists (n = 8) and prepared an 11-step checklist and a 5-point global rating scale for assessment. Novice learners (n = 15) were trained to reach the established skill proficiency in a Virtual Reality simulator for fiberoptic bronchoscopy skills and a Human Airway Anatomy Simulator for fiberoptic intubation skills. Two months later, novices were reassessed to determine decay in learned skills and the required time to retrain them to fiberoptic bronchoscopy proficiency level. RESULTS: Proficiency in fiberoptic bronchoscopy skill level was achieved with 11 ± 5 attempts and after 658 ± 351 s. After 2 months without practice, the time taken by the novices to successful fiberoptic bronchoscopy on the Virtual Reality simulator increased from 41 ± 8 to 68 ± 31 s (P = 0.0138). Time and attempts required to retrain them were 424 ± 230 s and 9.1 ± 4.6 attempts, respectively. CONCLUSION: Novices were successfully trained to proficiency skill level. Although fiberoptic bronchoscopy skills started to decay within 2 months, the re-training time was shorter.

Is video laryngoscope-assisted flexible tracheoscope intubation feasible for patients with predicted difficult airway? A prospective, randomized clinical trial.

BACKGROUND: Failed intubation may result in both increased morbidity and mortality. The combination of a video laryngoscope and a flexible tracheoscope used as a flexible video stylet may improve the success rate of securing a difficult airway. We tested the hypothesis that this combination is a feasible way to facilitate intubation in patients with a predicted difficult airway in that it will shorten intubation times and reduce the number of intubation attempts. METHODS: We conducted a randomized, prospective trial in 140 patients with anticipated difficult airways undergoing elective or urgent surgery. After insertion of video laryngoscope, patients were randomly assigned to either having their tube placed with the use of a preformed stylet (control group) or with a flexible tracheoscope (intervention group). The primary outcome measures were time to successful intubation and number of intubation attempts. RESULTS: The number of intubations requiring 2 or more intubation attempts was similar in the 2 groups (14% control vs 13% intervention, P = 1.0); the number of patients requiring 3 or more intubation attempts was not significantly different (8.6% control vs 1.4% intervention, P = 0.12). Distribution for time to intubation also did not differ between the control (median of 66 seconds, interquartile range 47-89) and the intervention group (median of 71 seconds, interquartile range 52-100; P = 0.35). In the control group, 4 patients, all with cervical spine pathology, had the trachea intubated successfully with the video laryngoscope plus flexible tracheoscope after 3 failed attempts with video laryngoscope and rigid stylet. For these 4 patients, time from the decision to change the intubation method to successful intubation with a flexible tracheoscope was 36 ± 14 seconds. Overall success probability for cervical spine patients was 100% (20/20) in the intervention group and 80% (16/20) in the control group, with an exact 95% confidence interval for the difference of 1.4% to 44%, P = 0.04. CONCLUSIONS: Flexible tracheoscope-assisted video laryngoscopic intubation is a feasible alternative to video laryngoscope only intubation in patients with predicted difficult airways. A flexible tracheoscope used in combination with video laryngoscope may also further increase the success rate of intubation in select patients with a proven difficult airway, particularly when in-line stabilization is required.

Right-Sided Pleural Effusion in a Critically Ill Stroke Patient.

Pleural fluid collections are common in those critically ill. We report the case of a left middle cerebral artery stroke patient who developed respiratory distress and required intubation and mechanical ventilation. Although the patient's clinical status and oxygenation improved, there was persistence of right-sided opacity in the chest radiograph. Further workup proved a right-sided pleural effusion, which was drained and managed. Following extubation, a swallow study was ordered, which led to a fluoroscopic examination that demonstrated esophageal perforation. Thoracic surgery was consulted and did a primary repair of perforation and noted non-small cell carcinoma on the perforated site.

Early postoperative subcutaneous tissue oxygen predicts surgical site infection.

BACKGROUND: Subcutaneous oxygen partial pressure is one of several determinants of surgical site infections (SSIs). However, tissue partial pressure is difficult to measure and requires invasive techniques. We tested the hypothesis that early postoperative tissue oxygen saturation (Sto(2)) measured with near-infrared spectroscopy predicts SSI. METHODS: We evaluated Sto(2) in 116 patients undergoing elective colon resection. Saturation was measured near the surgical incision, at the upper arm, and at the thenar muscle with an InSpectra™ tissue spectrometer model 650 (Hutchinson Technology Inc., Hutchinson, MN) 75 minutes after the end of surgery and on the first postoperative day. An investigator blinded to Sto(2) assessed patients daily for wound infection. Receiver operating characteristic curves were used to analyze the performance of Sto(2) measurements as a predictor of SSI. RESULTS: In 23 patients (≈ 20%), SSI was diagnosed 9 ± 5 days (mean ± SD) after surgery. Patients who did and did not develop an SSI had similar age (48 ± 14 vs 48 ± 15 years, respectively; P = 0.97) and gender (female:male, 15:8 vs 46:47, respectively), but patients who developed SSI weighed more (body mass index 32 ± 7 vs 27 ± 6 kg/m(2); P < 0.01). Sto(2) at the upper arm was lower in patients who developed SSI than in those who did not develop SSI (52 ± 22 vs 66 ± 21; P = 0.033), and these measurements had a sensitivity of 71% and specificity of 60% for predicting SSI, using Sto(2) of 66% as the cutoff point. CONCLUSION: Sto(2) measured at the upper arm only 75 minutes after colorectal surgery predicted development of postoperative SSI, although the infections were typically diagnosed more than a week later. Although further testing is required, Sto(2) measurements may be able to predict SSI and thus allow earlier preventive measures to be implemented.

Oxygen and surgical site infection: a study of underlying immunologic mechanisms.

BACKGROUND: Recent clinical trials investigating the role of hyperoxia in decreasing surgical site infection have reported conflicting results. Immunologic mechanisms through which supplemental oxygen could act have not been elucidated fully. The authors sought to investigate the effects of hyperoxia on previously tested and prognostically significant innate immune parameters to uncover the potential effects of hyperoxia at the cellular level. METHODS: After formal approval and informed consent, venous blood samples were collected from young healthy volunteers. Corresponding samples were incubated at 21 or 80% O2 following a 1 ng/ml lipopolysaccharide challenge and analyzed to determine human leukocyte antigen-DR surface receptor expression, cytokine release, phagocytic capacity, and formation of reactive oxygen species. Data are presented as mean +/- SD. RESULTS: After the 2 h of incubation at 21% O2 (room air) and in 80% O2 chambers, the change in human leukocyte antigen-DR mean channel fluorescence in lipopolysaccharide-stimulated monocytes was 2,177 +/- 383 and 2,179 +/- 338 (P = 0.96), respectively. Tumor necrosis factor-alpha concentrations were significantly lower for samples incubated at 80% O2 when compared with 21% O2 (P < 0.05). The phagocytic capacity of the innate immune system was not significantly enhanced by supplemental oxygen. However, the formation of reactive oxygen species increased by 87% (P < 0.05). CONCLUSION: Hyperoxia exerts significant effects on multiple cellular and immunologic parameters, providing a potential mechanism for benefits from the use of supplemental oxygen. However, the ability to translate positive basic scientific findings to the operating suite or bedside require the existence of similar innate immune processes in vivo and the efficient transfer of oxygen to the sites where it may be used.

The effect of aminophylline on loss of consciousness, bispectral index, propofol requirement, and minimum alveolar concentration of desflurane in volunteers.

BACKGROUND: Adenosine is a soporific neuromodulator; aminophylline, which is clinically used as a bronchodilator, antagonizes the action of adenosine in the central nervous system. Thus, we tested the hypothesis that aminophylline delays loss of consciousness (LOC) and speeds recovery of consciousness (ROC) with propofol anesthesia, and that aminophylline increases the minimum alveolar concentration (MAC) of desflurane. METHODS: In this double-blind crossover study, volunteers were randomized to either aminophylline or saline on different days. Aminophylline 6 mg/kg was given IV, followed by 1.5 mg x kg(-1) x h(-1) throughout the study day. After 1 h of aminophylline or saline administration, propofol 200 mg was given at a rate of 20 mg/min. The bispectral index was continuously monitored, as were times to LOC and ROC. After recovery from propofol, general anesthesia was induced with sevoflurane and subsequently maintained with desflurane. The Dixon "up-and-down" method was used to determine MAC in each volunteer after repeated tetanic electrical stimulation. RESULTS: Eight volunteers completed both study days. Time to LOC was prolonged by aminophylline compared with saline (mean +/- SD) (7.7 +/- 2.03 min vs 5.1 +/- 0.75 s, respectively, P = 0.011). The total propofol dose at LOC was larger with aminophylline (2.2 +/- 0.9 vs 1.4 +/- 0.4 mg/kg, P = 0.01), and the time to ROC was shorter (6.18 +/- 3.96 vs 12.2 +/- 4.73 min, P = 0.035). The minimum bispectral index was greater with aminophylline (51 +/- 15 vs 38 +/- 9, P = 0.034). There was no difference in MAC. CONCLUSION: Aminophylline decreases the sedative effects of propofol but does not affect MAC of desflurane as determined by tetanic electrical stimulation.

Accuracy of postoperative end-tidal Pco2 measurements with mainstream and sidestream capnography in non-obese patients and in obese patients with and without obstructive sleep apnea.

BACKGROUND: Obtaining accurate end-tidal carbon dioxide pressure measurements via nasal cannula poses difficulties in postanesthesia patients who are mouth breathers, including those who are obese and those with obstructive sleep apnea (OSA); a nasal cannula with an oral guide may improve measurement accuracy in these patients. The authors evaluated the accuracy of a mainstream capnometer with an oral guide nasal cannula and a sidestream capnometer with a nasal cannula that did or did not incorporate an oral guide in spontaneously breathing non-obese patients and obese patients with and without OSA during recovery from general anesthesia. METHODS: The study enrolled 20 non-obese patients (body mass index less than 30 kg/m) without OSA, 20 obese patients (body mass index greater than 35 kg/m) without OSA, and 20 obese patients with OSA. End-tidal carbon dioxide pressure was measured by using three capnometer/cannula combinations (oxygen at 4 l/min): (1) a mainstream capnometer with oral guide nasal cannula, (2) a sidestream capnometer with a nasal cannula that included an oral guide, and (3) a sidestream capnometer with a standard nasal cannula. Arterial carbon dioxide partial pressure was determined simultaneously. The major outcome was the arterial-to-end-tidal partial pressure difference with each combination. RESULTS: In non-obese patients, arterial-to-end-tidal pressure difference was 3.0 +/- 2.6 (mean +/- SD) mmHg with the mainstream capnometer, 4.9 +/- 2.3 mmHg with the sidestream capnometer and oral guide cannula, and 7.1 +/- 3.5 mmHg with the sidestream capnometer and a standard cannula (P < 0.05). In obese non-OSA patients, it was 3.9 +/- 2.6 mmHg, 6.4 +/- 3.1 mmHg, and 8.1 +/- 5.0 mmHg, respectively (P < 0.05). In obese OSA patients, it was 4.0 +/- 3.1 mmHg, 6.3 +/- 3.2 mmHg, and 8.3 +/- 4.6 mmHg, respectively (P < 0.05). CONCLUSIONS: Mainstream capnometry performed best, and an oral guide improved the performance of sidestream capnometry. Accuracy in non-obese and obese patients, with and without OSA, was similar.

Perioperative supplemental oxygen therapy and surgical site infection: a meta-analysis of randomized controlled trials.

OBJECTIVE: To conduct a meta-analysis of randomized controlled trials in which high inspired oxygen concentrations were compared with standard concentrations to assess the effect on the development of surgical site infections (SSIs). DATA SOURCES: A systematic literature search was conducted using the MEDLINE, EMBASE, and Cochrane databases and included a manual search of references of original articles, poster presentations, and abstracts from major meetings ("gray" literature). STUDY SELECTION: Twenty-one of 2167 articles met the inclusion criteria. Of these, 5 randomized controlled trials (3001 patients) assessed the effect of perioperative supplemental oxygen use on the SSI rate. Studies used a treatment-inspired oxygen concentration of 80%. Maximum follow-up was 30 days. DATA EXTRACTION: Data were abstracted by 3 independent reviewers using a standardized data collection form. Relative risks were reported using a fixed-effects model. Results were subjected to publication bias testing and sensitivity analyses. DATA SYNTHESIS: Infection rates were 12.0% in the control group and 9.0% in the hyperoxic group, with relative risk reduction of 25.3% (95% confidence interval [CI], 8.1%-40.1%) and absolute risk reduction of 3.0% (1.1%-5.3%). The overall risk ratio was 0.742 (95% CI, 0.599-0.919; P = .006). The benefit from increasing oxygen concentration was greater in colorectal-specific procedures, with a risk ratio of 0.556 (95% CI, 0.383-0.808; P = .002). CONCLUSIONS: Perioperative supplemental oxygen therapy exerts a significant beneficial effect in the prevention of SSIs. We recommend its use along with maintenance of normothermia, meticulous glycemic control, and preservation of intravascular volume perioperatively in the prevention of SSIs.

[Treatment of pediatric displaced supracondylar humerus fractures by fixation with two cross K-wires following reduction achieved after cutting the triceps muscle in a reverse V-shape]. / Cocuklardaki deplase suprakondiler humerus kiriklarinin tedavisinde triseps kasinin ters V seklinde kesilmesiyle saglanan redüksiyon ve iki adet çapraz K-teli ile tespit.

OBJECTIVES: We evaluated the results of surgical treatment for pediatric displaced supracondylar humerus fractures. METHODS: The study included 98 pediatric patients (72 boys, 26 girls; mean age 7 years; range 3 months to 14 years). According to the Gartland classification, all the displaced supracondylar humerus fractures were type III, being of flexion type in 10 patients (10.2%), and extension type in 88 patients (89.8%). Five were Gustilo-Anderson type 1 open fractures. All fractures were approached posteriorly. Reduction was achieved by cutting the triceps muscle in a reverse V-shape, followed by fixation using two cross K-wires from the epicondyles. The results were assessed according to the criteria of Flynn et al. At final follow-ups, elbow range of motion, the strength of the triceps muscle and, on radiographs, the carrying angle of the elbow, Baumann angle, and lateral humerocapitellar angle were measured. The mean follow-up was 42.6 months (range 7 to 80 months). RESULTS: According to the criteria of Flynn et al., 95 patients (96.9%) had perfect or good cosmetic results, 84 patients (85.7%) had perfect or good functional results. Elbow angles, elbow range of motion, and the strength of the triceps muscle were similar to those measured on the normal side (p>0.05). Time from injury to surgery did not have a significant influence on cosmetic and functional results (p>0.05). None of the patients exhibited procedure-related pin tract infection or insufficient bone union. Three patients (3.1%) developed cubitus varus deformity. CONCLUSION: Reduction of pediatric displaced supracondylar humerus fractures may be achieved easily by the posterior approach, after cutting the triceps muscle in a reverse V-shape, and fixation with two cross-pinned K-wires provides adequate stability. This procedure does not result in weakness of the triceps muscle.