Surgical site infection in abdominal trauma patients: risk prediction and performance of the NNIS and SENIC indexes

Development and validation of a nomogram to predict postsurgical intra-abdominal infection in blunt abdominal trauma patients: A multicenter retrospective study

BACKGROUND

Intra-abdominal infection is a common complication of blunt abdominal trauma. Early detection and intervention can reduce the incidence of intra-abdominal infection and improve patients' prognoses. This study aims to construct a clinical model predicting postsurgical intra-abdominal infection after blunt abdominal trauma.

METHODS

This study is a retrospective analysis of 553 patients with blunt abdominal trauma from the Department of General Surgery of 7 medical centers (2011-2021). A 7:3 ratio was used to assign patients to the derivation and validation cohorts. Patients were divided into 2 groups based on whether intra-abdominal infection occurred after blunt abdominal trauma. Multivariate logistic regression and least absolute shrinkage and selection operator regression were used to select variables to establish a nomogram. The nomogram was evaluated, and the validity of the model was further evaluated by the validation cohort.

RESULTS

A total of 113 were diagnosed with intra-abdominal infection (20.4%). Age, prehospital time, C-reactive protein, injury severity score, operation duration, intestinal injury, neutrophils, and antibiotic use were independent risk factors for intra-abdominal infection in blunt abdominal trauma patients (P < .05). The area under the receiver operating curve (area under the curve) of derivation cohort and validation cohort was 0.852 (95% confidence interval, 0.784-0.912) and 0.814 (95% confidence interval, 0.751-0.902). The P value for the Hosmer-Lemeshow test was .135 and .891 in the 2 cohorts. The calibration curve demonstrated that the nomogram had a high consistency between prediction and practical observation. The decision curve analysis also showed that the nomogram had a better potential for clinical application. To facilitate clinical application, we have developed an online at https://nomogramcgz.shinyapps.io/IAIrisk/.

CONCLUSION

The nomogram is helpful in predicting the risk of postoperative intra-abdominal infection in patients with blunt abdominal trauma and provides guidance for clinical decision-making and treatment.

0.05% Chlorhexidine Gluconate Irrigation in Trauma/Emergency General Surgical Laparotomy Wounds Closure: A Pilot Study

INTRODUCTION

Patients who undergo exploratory laparotomy (EL) in an emergent setting are at higher risk for surgical site infections (SSIs) compared to the elective setting. Packaged Food and Drug Administration-approved 0.05% chlorhexidine gluconate (CHG) irrigation solution reduces SSI rates in nonemergency settings. We hypothesize that the use of 0.05% CHG irrigation solution prior to closure of emergent EL incisions will be associated with lower rates of superficial SSI and allows for increased rates of primary skin closure.

METHODS

A retrospective observational study of all emergent EL whose subcutaneous tissue were irrigated with 0.05% CHG solution to achieve primary wound closure from March 2021 to June 2022 were performed. Patients with active soft-tissue infection of the abdominal wall were excluded. Our primary outcome is rate of primary skin closure following laparotomy. Descriptive statistics, including t-test and chi-square test, were used to compare groups as appropriate. A P value <0.05 was statistically significant.

RESULTS

Sixty-six patients with a median age of 51 y (18-92 y) underwent emergent EL. Primary wound closure is achieved in 98.5% of patients (65/66). Bedside removal of some staples and conversion to wet-to-dry packing changes was required in 27.3% of patients (18/66). We found that most of these were due to fat necrosis. We report no cases of fascial dehiscence.

CONCLUSIONS

In patients undergoing EL, intraoperative irrigation of the subcutaneous tissue with 0.05% CHG solution is a viable option for primary skin closure. Further studies are needed to prospectively evaluate our findings.

Prognostic models for surgical-site infection in gastrointestinal surgery: systematic review

BACKGROUND

Identification of patients at high risk of surgical-site infection may allow clinicians to target interventions and monitoring to minimize associated morbidity. The aim of this systematic review was to identify and evaluate prognostic tools for the prediction of surgical-site infection in gastrointestinal surgery.

METHODS

This systematic review sought to identify original studies describing the development and validation of prognostic models for 30-day SSI after gastrointestinal surgery (PROSPERO: CRD42022311019). MEDLINE, Embase, Global Health, and IEEE Xplore were searched from 1 January 2000 to 24 February 2022. Studies were excluded if prognostic models included postoperative parameters or were procedure specific. A narrative synthesis was performed, with sample-size sufficiency, discriminative ability (area under the receiver operating characteristic curve), and prognostic accuracy compared.

RESULTS

Of 2249 records reviewed, 23 eligible prognostic models were identified. A total of 13 (57 per cent) reported no internal validation and only 4 (17 per cent) had undergone external validation. Most identified operative contamination (57 per cent, 13 of 23) and duration (52 per cent, 12 of 23) as important predictors; however, there remained substantial heterogeneity in other predictors identified (range 2-28). All models demonstrated a high risk of bias due to the analytic approach, with overall low applicability to an undifferentiated gastrointestinal surgical population. Model discrimination was reported in most studies (83 per cent, 19 of 23); however, calibration (22 per cent, 5 of 23) and prognostic accuracy (17 per cent, 4 of 23) were infrequently assessed. Of externally validated models (of which there were four), none displayed 'good' discrimination (area under the receiver operating characteristic curve greater than or equal to 0.7).

CONCLUSION

The risk of surgical-site infection after gastrointestinal surgery is insufficiently described by existing risk-prediction tools, which are not suitable for routine use. Novel risk-stratification tools are required to target perioperative interventions and mitigate modifiable risk factors.

Reduction of Surgical Site Infection After Trauma Laparotomy Through Use of a Specific Protocol for Antibiotic Prophylaxis

Background: Emergency laparotomy for abdominal trauma is associated with high rates of surgical site infection (SSI). A protocol for antimicrobial prophylaxis (AMP) for trauma laparotomy was implemented to determine whether SSI could be reduced by adhering to established principles of AMP. Patients and Methods: A protocol utilizing ertapenem administered immediately before initiation of trauma laparotomy was adopted. Compliance with measures of adequate AMP were determined before and after protocol implementation, as were rates of SSI and other infections related to abdominal trauma. Univariable and multivariable analyses were performed to determine risk factors for development of infection related to trauma laparotomy. Results: Over a four-year period, 320 patient operations were reviewed. Ertapenem use for prophylaxis increased to 54% in the post-intervention cohort. Compliance with individual measures of appropriate AMP improved modestly. Overall, infections related to trauma laparotomy decreased by 46% (absolute decrease of 13%) in the post-intervention cohort. Multivariable analysis confirmed that treatment during the post-intervention phase was associated with this decrease, with a separate analysis suggesting that ertapenem use was an important factor in this decrease. Conclusions: Development of a standardized protocol for AMP in trauma laparotomy led to decreases in infectious complications after that procedure.

The Burden of Surgical Site Infection at Hospital Universiti Sains Malaysia and Related Postoperative Outcomes: A Prospective Surveillance Study

Surgical site infections (SSIs) are the most common healthcare-associated infections that occur among surgical patients. Surgical site infections result in longer hospital stays, hospital readmissions, and higher death and morbidity rates. The current study was designed to highlight the importance of such surveillance studies in a Malaysian surgical population with a motive to evaluate and revise concurrent infection control and prevention policies by exploring the burden of surgical site infection and identifying its associated risk factors for future considerations. In this prospective observational cohort study, a total of 216 patients admitted to a surgical ward were identified and studied. Of these 216 patients, 142 elective procedures and 74 emergency procedures were included in the study, of which 13 patients (9.2%) undergoing elective procedures and 15 (20.3%) patients undergoing emergency procedures were SSI positive (OR: 2.5, p = 0.02). Among surgical site infections, 21 were superficial and 7 were deep incisional SSI. No case of organ/space SSI was identified. The time taken for SSIs to develop ranged from 2-17 days with a median of 6 days. Risk factors such as presence of comorbidities (p = 0.011), major co-existing medical diagnosis ≥2 (p = 0.02), and pre-existing infection (p = 0.027) were statistically significant. SSI-positive patients experienced an increase in the post-operative length of hospital stay. In the current population, it was seen that identifying patients who were at high risk of malnutrition via MUST and the NNIS risk index will help clinicians in identifying high risk patients and in managing their patients appropriately. Identifying patients who were at high risk of malnutrition will also improve postoperative outcomes considerably.

Determination of risk factors associated with surgical site infection in patients undergoing preperitoneal pelvic packing for unstable pelvic fracture

Background

Several recent studies have shown that preperitoneal pelvic packing (PPP) effectively produces hemostasis in patients with unstable pelvic fractures. However, few studies have examined the rate of surgical site infections (SSIs) in patients undergoing PPP following an unstable pelvic fracture. The purpose of the present study was to evaluate factors associated with SSI in such patients.

Methods

We retrospectively reviewed the medical charts of 188 patients who developed hemorrhagic shock due to pelvic fracture between April 2012 and May 2021. Forty-four patients were enrolled in this study.

Results

SSI occurred in 15 of 44 patients (34.1%). The SSIs occurred more frequently in cases of repacking during the second-look surgery (0 vs. 4 [26.7%], P=0.010) and combined bladder-urethra injury (1 [3.4%] vs. 4 [26.7%], P=0.039). The incidence of SSIs was not significantly different between patients undergoing depacking within or after 48 hours (12 [41.4%] vs. 5 [33.3%], P=0.603). The mean time to diagnosis of SSI was 8.1±3.9 days from PPP. The most isolated organism was Staphylococcus epidermidis.

Conclusions

Repacking and combined bladder-urethra injury are potential risk factors for SSI in patients with unstable pelvic fracture. Close observation is recommended for up to 8 days in patients with these risk factors. Further, 48 hours after PPP, removing the packed gauze on cessation of bleeding and not performing repacking can help prevent SSI. Additional analyses are necessary with a larger number of patients with the potential risk factors identified in this study.

Incisional Negative Pressure Wound Therapy to Decrease the Incidence of Surgical Site Infections in Trauma Laparotomy Wounds

BACKGROUND

Surgical site infection (SSI) is a common post-operative complication, especially in trauma laparotomies. Incisional negative pressure wound therapy (iNPWT) is a novel technique in reducing SSIs. We aim to study the rate of wound complications in trauma laparotomy with standard primary closure with staples vs iNPWT.

METHODS

We had 152 patients meeting inclusion criteria who underwent emergent trauma laparotomies performed at Sentara Norfolk General from 2017 to 2020. We had 79 patients in the standard staple group and 73 patients in the iNWPT group. We then analyzed surgical site infection rates and wound complication rates in both groups within a 30-day period.

RESULTS

The wound infection rate in the staple vs staple plus iNPWT was 10.0% vs 3.8%, respectively (P = .13). Wound dehiscence rates were 24.1% vs 10.13%, respectively (P = .02). When looking at a subset of patients with hollow viscous injury, the rate of SSIs was statistically lower in the iNPWT group. Prior to the introduction of the incisional vacuum-assisted closure (VAC) to our practice compared to after its introduction, 39.25% of wounds were left open vs 19.51%, respectively (P = .001).

CONCLUSION

Our data identified a trend toward a decrease in overall SSIs in trauma laparotomies closed with iNPWT. The use of iNPWT demonstrated a decrease in superficial wound dehiscence and a decrease in SSIs in patients with associated full thickness bowel injury. With iNPWT, we are more aggressive with primarily closing trauma laparotomy wounds. This shows promise for increasing primary closure rates while simultaneously decreasing overall superficial surgical site infection rate.

Combination of early Interleukin-6 and -18 levels predicts postoperative nosocomial infection

BACKGROUND

The inflammatory response plays a critical role in postoperative nosocomial infections, which are the most common postoperative complications causing adverse events and poor postoperative outcomes. This study aimed to explore the ability of early inflammation-related factor levels to predict the occurrence of nosocomial infections after abdominal surgery.

METHODS

The study included 146 patients with open abdominal surgery (a nosocomial infection group (NI group, n=42) and a no-nosocomial infection group (NNI group, n=104)). After 1:1 matching, the patients were divided into a matching nosocomial infection group (M-NI group, n=25) and a matching no-nosocomial infection group (M-NNI group, n=25). Serum levels of interleukin (IL)-6, IL-8, IL-10, IL-12, IL-18, macrophage migration inhibitory factor (MIF), and monocyte chemotactic protein (MCP-1) were tested at three time points (pre-operation, 0-hour post-operation (POD1) and 24-hour post-operation (POD2)). The area under the receiver operating characteristic curve (AUC-ROC) was used to test the predictive abilities.

RESULTS

There were significant differences in the levels of IL-6, IL-12, and IL-18 between the M-NI and M-NNI groups (p < 0.05), but not in the levels of other inflammatory factors. MIF, IL-8, and MCP-1 levels were higher in the M-NI group than in the M-NNI group at POD2 (p < 0.05). In the ROC analysis, the AUC for prediction of nosocomial infection using a combination of IL-6 and IL-18 at POD1 was 0.9616, while the AUCs for IL-6 alone and IL-12 alone were 0.8584 and 0.8256, respectively.

CONCLUSIONS

The combination of the levels of inflammatory factors, IL-6 and IL-18, at the 0-hour postoperative time point, significantly improved the predictive ability to the development of postoperative infection during perioperative period. Our study suggests the importance of monitoring postoperative inflammatory markers.

Risk Stratification for Superficial Surgical Site Infection after Emergency Trauma Laparotomy

Background: Superficial surgical site infections (S-SSIs) are common after trauma laparotomy, leading to morbidity, increased costs, and prolonged length of stay (LOS). Opportunities to mitigate S-SSI risks are limited to the intra-operative and post-operative periods. Accurate S-SSI risk stratification is paramount at the time of operation to inform immediate management. We aimed to develop a risk calculator to aid in surgical decision-making at the time of emergency laparotomy. Methods: A retrospective cohort study of patients requiring emergency trauma laparotomy between 2011 and 2017 at a single, level 1 trauma center was performed. Operative factors, skin management strategy, and outcomes were determined by chart review. Bayesian multilevel logistic regression was utilized to create a risk calculator with variables available upon closure of the laparotomy. Models were validated on a 30% test cohort and discrimination reported as an area under the receiver operating characteristics curve (AUROC). Results: Of 1,322 patients, the majority were male (77%) with median age of 33 years, injured by blunt mechanism (54%), and median injury severity score of 19. Eighty-eight (7%) patients developed an S-SSI. Patients who developed S-SSI had higher final lactate, blood loss, transfusion requirements, and wound classification. Patients with S-SSI more frequently had mesenteric or large bowel injury than those without S-SSI. Superficial SSI was associated with increased complications and prolonged length of stay (LOS). The S-SSI predictive model demonstrated moderate discrimination with an AUROC of 0.69 (95% confidence interval [CI], 0.56-0.81). Parameters contributing the most to the model were damage control laparotomy, full-thickness large bowel injury, and large bowel resection. Conclusion: A predictive model for S-SSI was built using factors available to the surgeon upon index emergency trauma laparotomy closure. This calculator may be used to standardize intra- and post-operative care and to identify high-risk patients in whom to test novel preventative strategies and improve overall outcomes for patients requiring emergency trauma laparotomy.

Risk factors for abdominal surgical site infection after exploratory laparotomy among combat casualties

BACKGROUND

Surgical site infections (SSIs) are well-recognized complications after exploratory laparotomy for abdominal trauma; however, little is known about SSI development after exploration for battlefield abdominal trauma. We examined SSI risk factors after exploratory laparotomy among combat casualties.

METHODS

Military personnel with combat injuries sustained in Iraq and Afghanistan (June 2009 to May 2014) who underwent laparotomy and were evacuated to participating US military hospitals were included. Log-binominal regression was used to identify SSI risk factors.

RESULTS

Of 4,304 combat casualties, 341 patients underwent a total of 1,053 laparotomies. Abdominal SSIs were diagnosed in 49 patients (14.4%): 8% with organ space SSI, 4% with deep incisional SSI, and 4% with superficial SSIs (4 patients had multiple SSIs). Patients with SSIs had more colorectal (p < 0.001), small bowel (p = 0.010), duodenum (p = 0.006), pancreas (p = 0.032), and abdominal vascular injuries (p = 0.040), as well as prolonged open abdomen (p = 0.004) and more infections diagnosed before the SSI (or final exploratory laparotomy) versus non-SSI patients (p < 0.001). Sustaining colorectal injuries (risk ratio [RR], 3.20; 95% confidence interval [CI], 1.58-6.45), duodenum injuries (RR, 6.71; 95% CI, 1.73-25.58), and being diagnosed with prior infections (RR, 10.34; 95% CI, 5.05-21.10) were independently associated with any SSI development. For either organ space or deep incisional SSIs, non-intra-abdominal infections, fecal diversion, and duodenum injuries were independently associated, while being injured via an improvised explosive device was associated with reduced likelihood compared with penetrating nonblast (e.g., gunshot wounds) injuries. Non-intra-abdominal infections and hypotension were independently associated with organ space SSIs development alone, while sustaining blast injuries were associated with reduced likelihood.

CONCLUSION

Despite severity of injuries and the battlefield environment, the combat casualty laparotomy SSI rate is relatively low at 14%, with similar risk factors and rates reported following severe civilian trauma.

LEVEL OF EVIDENCE

Epidemiological, level III.

Outcomes of Exploratory Laparotomy and Abdominal Infections Among Combat Casualties

BACKGROUND

Abdominal injuries historically account for 13% of battlefield surgical procedures. We examined the occurrence of exploratory laparotomies and subsequent abdominal surgical site infections (SSIs) among combat casualties.

METHODS

Military personnel injured during deployment (2009-2014) were included if they required a laparotomy for combat-related trauma and were evacuated to Landstuhl Regional Medical Center, Germany, before being transferred to participating US military hospitals.

RESULTS

Of 4304 combat casualties, 341 (7.9%) underwent laparotomy. Including re-explorations, 1053 laparotomies (median, 2; interquartile range, 1-3; range, 1-28) were performed with 58% occurring within the combat zone. Forty-nine (14.4%) patients had abdominal SSIs (four with multiple SSIs): 27 (7.9%) with deep space SSIs, 14 (4.1%) with a deep incisional SSI, and 12 (3.5%) a superficial incisional SSI. Patients with abdominal SSIs had larger volume of blood transfusions (median, 24 versus 14 units), more laparotomies (median, 4 versus 2), and more hollow viscus injuries (74% versus 45%) than patients without abdominal SSIs. Abdominal closure occurred after 10 d for 12% of the patients with SSI versus 2% of patients without SSI. Mesh adjuncts were used to achieve fascial closure in 20.4% and 2.1% of patients with and without SSI, respectively. Survival was 98% and 96% in patients with and without SSIs, respectively.

CONCLUSIONS

Less than 10% of combat casualties in the modern era required abdominal exploration and most were severely injured with hollow viscus injuries and required massive transfusions. Despite the extensive contamination from battlefield injuries, the SSI proportion is consistent with civilian rates and survival was high.

Random forest modeling can predict infectious complications following trauma laparotomy

BACKGROUND

Identifying clinical and biomarker profiles of trauma patients may facilitate the creation of models that predict postoperative complications. We sought to determine the utility of modeling for predicting severe sepsis (SS) and organ space infections (OSI) following laparotomy for abdominal trauma.

METHODS

Clinical and molecular biomarker data were collected prospectively from patients undergoing exploratory laparotomy for abdominal trauma at a Level I trauma center between 2014 and 2017. Machine learning algorithms were used to develop models predicting SS and OSI. Random forest (RF) was performed, and features were selected using backward elimination. The SS model was trained on 117 records and validated using the leave-one-out method on the remaining 15 records. The OSI model was trained on 113 records and validated on the remaining 19. Models were assessed using areas under the curve.

RESULTS

One hundred thirty-two patients were included (median age, 30 years [23-42 years], 68.9% penetrating injury, median Injury Severity Score of 18 [10-27]). Of these, 10.6% (14 of 132) developed SS and 13.6% (18 of 132) developed OSI. The final RF model resulted in five variables for SS (Penetrating Abdominal Trauma Index, serum epidermal growth factor, monocyte chemoattractant protein-1, interleukin-6, and eotaxin) and four variables for OSI (Penetrating Abdominal Trauma Index, serum epidermal growth factor, monocyte chemoattractant protein-1, and interleukin-8). The RF models predicted SS and OSI with areas under the curve of 0.798 and 0.774, respectively.

CONCLUSION

Random forests with RFE can help identify clinical and biomarker profiles predictive of SS and OSI after trauma laparotomy. Once validated, these models could be used as clinical decision support tools for earlier detection and treatment of infectious complications following injury.

LEVEL OF EVIDENCE

Prognostic, level III.

Unplanned surgical reoperations as a quality indicator in pediatric tertiary general surgical specialties: Associated risk factors and hospitalization, a retrospective case-control analysis

Unplanned reoperations have not been studied extensively in pediatric patients, especially concerning risk factors. We aim to estimate the rate of unplanned reoperations and to determine the associated factors in pediatric general surgical specialties.This analysis included a retrospective case-control study of unplanned reoperations from July 1, 2010 to June 30, 2017 in the general surgical specialties. For each case, we identified approximately 2 randomly selected controls who underwent the same type of operation. The factors involved in the unplanned reoperations were investigated using univariate and multivariate analysis.Of the 3263 patients who underwent surgery, unplanned reoperations were performed in 139 patients (4.3%). The main indications for unplanned reoperations were wound complications (n = 52, 42.6%), followed by postoperative ileus (n = 12, 9.8%), postoperative bleeding (n = 8, 6.6%), and intraabdominal infection (n = 13, 10.7%). Following multivariate analysis, 2 factors remained significantly associated with unplanned reoperation: higher initial surgery-related risk level (P = .007, risk ratio (RR) = 0.48; 95% confidence interval (CI) = 0.27-0.82) and operation performed outside working hours (P = .031, RR = 0.52; 95% CI = 0.30-0.89).Various patient- and procedure-related factors were associated with unplanned reoperations. This information might be helpful for the optimization of treatment planning and resource allocation.

Outcomes, Microbiology and Antimicrobial Usage in Pressure Ulcer-Related Pelvic Osteomyelitis: Messages for Clinical Practice

Introduction: Pressure ulcer-related pelvic osteomyelitis is a relatively under-studied entity in the field of bone infection. We sought to add to the limited evidence base for managing this challenging syndrome.

Methods: Cases were identified retrospectively from a surgical database and hospital discharge codes at a U.K. tertiary centre (2009-2018). Risk factors associated with outcomes were analysed by logistic regression.

Results: We identified 35 patients (mean age 57.4 years), 69% managed with a combined medical and surgical approach, with mean follow-up of 3.7 years from index admission. Treatment failure (requiring further surgery or intravenous antimicrobials) occurred in 71% and eventual ulcer healing in 36%. One-year mortality was 23%. Lack of formal care support on discharge, post-traumatic (asensate) neurological deficit and index CRP (>184mg/L) were associated with treatment failure (p=0.001). Age (>59.5 years), lack of attempted soft tissue coverage, haemoglobin (<111g/L) and albumin (<25g/L) were associated with non-healing ulcers (p=0.003). Superficial wound swabs had low sensitivity and specificity compared to deep bone microbiology. Infection (based on deep bone microbiology from 46 infection episodes) was usually polymicrobial (87%), commonly involving S. aureus, Enterococci, GNB and anaerobes. Antimicrobial duration ranged from 0-103 days (mean 54) and was not associated with subsequent treatment failure.

Conclusions: Attempted soft tissue coverage after surgical debridement, ensuring appropriate support for personal care after discharge and nutritional optimisation could improve outcomes. Superficial wound swabs are uninformative and deep bone sampling should be pursued. Long antimicrobial courses do not improve outcomes. Clinicians should engage patients in anticipatory care planning.

Primary Skin Closure after Repair of Hollow Viscus Injuries

Decisions regarding whether to close the skin in trauma patients with hollow viscus injuries (HVIs) are based on surgeon discretion and the perceived risk for an SSI. We hypothesized that leaving the skin open would result in fewer wound complications in patients with HVIs. We performed a retrospective analysis of all adult patients who underwent operative repair of an HVI. The main outcome measure was superficial or deep SSIs. Of 141 patients, 38 (27%) had HVIs. Twenty-six patients developed SSIs, of which 13 (50%) were superficial or deep SSIs. On adjusted analysis, only female gender ( P = 0.03) and base deficit were associated ( P = 0.001) with wound infections Open wound management was not associated with a decreased incidence of SSIs ( P = 0.19) in patients with HVIs. Further research is required to determine optimal strategies for reducing wound complications in patients sustaining HVIs.

Surgical site infections after trauma laparotomy. An observational study from a major trauma center in Saudi Arabia

OBJECTIVES

To determine the incidence of surgical site infection (SSI) after trauma laparotomy and evaluate variables on presentation to the emergency department (ED) associated with the development of SSI. Methods: A retrospective cohort study was undertaken of patients presenting directly from the scene who underwent trauma laparotomy between January 2016 and December 2017. The primary outcome variable was SSI, as defined by the Centers for Disease Control and Prevention guideline. A univariate assessment with demographics, vital signs, and acute management was reported. Results: A total of 70 patients were included for data analysis. Of these, 9 (12.9%; 95% confidence interval (CI): 6.9-22.7%) patients developed SSI, including 5 patients with bowel injury (small bowel; n=3, colonic injuries; n=2). Most cases were diagnosed after 7 days in the hospital. All patients developed superficial incisional (skin and subcutaneous tissue) SSI. No predetermined variables, including bowel injury (p=0.08) or duration of surgery (p=0.09), demonstrated a statistically significant association with the development of SSI. Conclusion: Rates of SSI after trauma laparotomy were similar to previous reports from other centers. Surgical site infection after trauma laparotomy was diagnosed at a delayed time point after surgery, and patient demographics, injury characteristics, and acute surgical management did not appear to be associated with subsequent diagnosis of SSI.

Accurate risk stratification for development of organ/space surgical site infections after emergent trauma laparotomy

BACKGROUND

Organ/space surgical site infection (OS-SSI) develops frequently after trauma laparotomies and is associated with significant morbidity. No valid model exists to accurately risk-stratify the probability of OS-SSI development after emergent laparotomy. Risk stratification for OS-SSI in these patients could guide promising, but unproven, interventions for OS-SSI prevention, such as more frequent dosing of intraoperative antibiotics or direct peritoneal resuscitation. We hypothesize that in trauma patients who undergo emergent laparotomy, probability of OS-SSI can be accurately estimated using patient data available during the index operation.

METHODS

Retrospective review was performed on a prospectively maintained database of emergent trauma laparotomies from 2011 to 2016. Patient demographics and risk factors for OS-SSI were collected. We performed Bayesian multilevel logistic regression to develop the model based on a 70% training sample. Evaluation of model fit using area under the curve was performed on a 30% test sample. The Bayesian approach allowed the model to address clustering of patients within physician while implementing regularization to improve predictive performance on test data.

RESULTS

One hundred seventy-two (15%) of 1,171 patients who underwent laparotomy developed OS-SSI. Variables thought to affect development of surgical site infections and were available to the surgeon near the conclusion of the trauma laparotomy were included in the model. Two variables that contributed most to OS-SSIs were damage-control laparotomy and colon resection. The area under the curve of the predictive model validated on the test sample was 0.78 (95% confidence interval, 0.71-0.85).

CONCLUSION

Using a combination of factors available to surgeons before the end of an emergent laparotomy, the probability of OS-SSI could be accurately estimated using this retrospective cohort. A Web-based calculator is under design to allow the real-time estimation of probability of OS-SSI intraoperatively. Prospective validation of its generalizability to other trauma cohorts and of its utility at the point of care is required.

LEVEL OF EVIDENCE

Prognostic study, level IV.

A Randomized Controlled Trial on Intra-Abdominal Irrigation during Emergency Trauma Laparotomy; Time for Yet Another Paradigm Shift

OBJECTIVE

To determine the optimal volume of abdominal irrigation that will prevent surgical site infections (both deep and superficial), eviscerations and fistula formations; and improve 30-day mortality in trauma patients.

METHODS

We conducted a three-arm parallel clinical superiority randomized controlled trial comparing different volumes of effluent (5, 10 and 20 liters) used in trauma patients (both blunt and penetrating) age 14 and above undergoing an emergency laparotomy between April 2002 and July 2004 in a busy urban Level 1 trauma center.

RESULTS

After randomization, a total of 204 patients were analyzed. All patient groups were comparable with respect to age, gender distribution, admission injury severity score, and mechanism of injury, estimated blood loss and degree of contamination. The mortality rate overall was 1.96% (4/204).No differences were noted with respect to contamination, wound infection, fistula formation, and evisceration. The twenty liter group (Group III) showed a trend toward an increased incidence of deep surgical site infections when compared to the five liter (Group I) (p=0.051) and ten liter (Group II) (p=0.057) groups. This did not however reach statistical significance.

CONCLUSION

The old surgical adage "the solution to pollution is dilution" is not applicable to trauma patients. Our results suggest that using more irrigation, even when large amounts of contamination have occurred, does not reduce post-operative complications or affect mortality; and it may predispose patients to increased incidence of abscess formation. (Trial registration number: ISRCTN66454589).

Surgical wound assessment by sonography in the prediction of surgical wound infections

BACKGROUND

Surgical site infections (SSIs) are important sources of morbidity, prolonged hospital stays, and readmissions, so they have become a major economic burden. We hypothesized that surgical wound assessment by sonography (SWATS) used at the bedside would detect wound fluid collections and that the presence of such collections would predict SSI better than standard clinical examination. If so, SWATS might be used to indicate early intervention that could prevent SSI morbidity.

METHODS

A prospective, single-institution observational study was conducted on adult inpatients following open abdominal surgery for trauma, gastrointestinal pathology, or biliary pathology at high risk (>5%) for SSI using traditional wound classifications. After informed consent was obtained, SWATS was performed using a smartphone-based ultrasound system on postoperative Day 2 to 4 and again before discharge or at postoperative Day 30, whichever came first. Primary treating physicians delivered standard wound care and were blinded to SWATS. SSI was diagnosed if treatment was implemented for suspected or documented wound infection by the treating physician. Results were analyzed by χ test and two-sample pooled variance t test where appropriate, with significance set at p < 0.05.

RESULTS

Forty-nine patients were studied. Nineteen patients had peri-incisional fluid collections found by SWATS. Eight of these patients went on to develop an SSI. SSI was significantly associated with the presence of fluid collections on SWATS (p = 0.009). SWATS had a sensitivity of 72.7% (0.43-0.92), a specificity of 71.1% (0.62-0.77), a positive predictive value of 42.1% (0.25-0.53), and a negative predictive value of 90.0% (0.79-0.97).

CONCLUSION

SWATS has a high negative predictive value that may allow it be an effective screening tool for developing SSI in high-risk surgical wounds. SWATS has the potential to be a useful and cost-effective adjunct to the clinician by objectively suggesting need for early therapy. Further study with larger sample sizes and randomized, SWATS-based interventions are required to validate this small study and determine its place in clinical care.

LEVEL OF EVIDENCE

Diagnostic study, level IV.

The burden of infection in severely injured trauma patients and the relationship with admission shock severity

BACKGROUND

Infection following severe injury is common and has a major impact on patient outcomes. The relationship between patient, injury, and physiologic characteristics with subsequent infections is not clearly defined. The objective of this study was to characterize the drivers and burden of all-cause infection in critical care trauma patients.

METHODS

A prospective cohort study of severely injured adult patients admitted to critical care was conducted. Data were collected prospectively on patient and injury characteristics, baseline physiology, coagulation profiles, and blood product use. Patients were followed up daily for infectious episodes and other adverse outcomes while in the hospital.

RESULTS

Three hundred patients (Injury Severity Score [ISS] >15) were recruited. In 48 hours or less, 29 patients (10%) died, leaving a cohort of 271. One hundred forty-one patients (52%) developed at least one infection. Three hundred four infections were diagnosed overall. Infection and noninfection groups were matched for age, sex, mechanism, and ISS. Infection rates were greater with any degree of admission shock and threefold higher in the most severely shocked cohort (p < 0.01). In multivariate analysis, base deficit (odds ratio [OR], 1.78, 95% confidence interval [CI], 1.48-1.94; p < 0.001) and lactate (OR, 1.36; 95% CI, 1.10-1.69; p = 0.05) were independently associated with the development of infection. Outcomes were significantly worse for the patients with infection. In multivariate logistic regression, infection was the only factor independently associated with multiple-organ failure (p < 0.001; OR, 15.4; 95% CI, 8.2-28.9; r = 0.402), ventilator-free days (p < 0.001; β, -4.48; 95% CI, -6.7 to -2.1; r = 0.245), critical care length of stay (p < 0.001; β, 13.2; 95% CI, 10.0-16.4; r = 0.466), and hospital length of stay (p < 0.001; β, 31.1; 95% CI, 24.0-38.2; r = 0.492).

CONCLUSION

Infectious complications are a burden for severely injured patients and occur early in the critical care stay. Severity of admission shock was predictive of infection and represents an opportunity for interventions to improve infectious outcomes. The incidence of infection may also have utility as an end point for clinical trials in trauma hemorrhage given the relationship with patient-experienced outcomes.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level II.

Frequency of bacterial agents isolated from patients with nosocomial infection in teaching hospitals of Mazandaran University of Medical Sciences in 2012

BACKGROUND

The antibiotic resistance of nosocomial organisms is rapidly increasing. The purpose of this study was to determine the frequency of bacterial agents isolated from patients with nosocomial infection.

METHODS

This study was performed in the different wards of teaching hospitals of Mazandaran University of Medical Sciences (northern Iran). The study population consists of the patients with the symptoms of nosocomial infection admitted in these hospitals in 2012. The patient data (including age, sex, type of infection, type of isolated organisms and their antibiotic susceptibility) were collected and analyzed.

RESULTS

The total number of hospitalizations was 57122 and the number of nosocomial infection was 592. The overall prevalence of nosocomial infection was 1.03% that was mostly in Burn unit and intensive care unit. The most common nosocomial infection was wound infection (44.6%) and the most common organisms were Pseudomonas aeruginosa and Acinetobacter.

CONCLUSION

Given the increasing numbers of nosocomial infection in this region, especially infection with Pseudomonas aeruginosa, it is necessary to make a precise reporting and improve the procedures of infection control in hospitals.

Predictive model for surgical site infection risk after surgery for high-energy lower-extremity fractures: development of the risk of infection in orthopedic trauma surgery score

BACKGROUND

Current infection risk scores are not designed to predict the likelihood of surgical site infection after orthopedic fracture surgery. We hypothesized that the National Nosocomial Infections Surveillance (NNIS) System and the Study on the Efficacy of Nosocomial Infection Control (SENIC) scores are not predictive of infection after orthopedic fracture surgery and that risk factors for infection can be identified and a new score created (Emerg Infect Dis. 2003;9:196-203).

METHODS

We conducted a secondary analysis of data from a trial involving internal fixation of 235 tibial plateau, pilon, and calcaneus fractures treated between 2007 and 2010 at a Level I trauma center. The predictive value of the NNIS System and SENIC scores was evaluated based on areas under the receiver operating characteristic (ROC) curve. Bivariate and multiple logistic regression analyses were used to build an improved prediction model, creating the Risk of Infection in Orthopedic Trauma Surgery (RIOTS) score. The predictive value of the RIOTS score was evaluated via the ROC curve.

RESULTS

NNIS System and SENIC scores were not predictive of surgical site infection after orthopedic fracture surgery. In our final regression model, the relative odds of infection among patients with AO [Arbeitsgemeinschaft für Osteosynthesefragen] type C3 or Sanders type 4 fractures compared with fractures of lower classification was 5.40. American Society of Anesthesiologists class 3 or higher and body mass index less than 30 were also predictive of infection, with odds ratios of 2.87 and 3.49, respectively. The area under the ROC curve for the RIOTS score was 0.75, significantly higher than the areas for the NNIS System and SENIC scores.

CONCLUSION

The NNIS System and SENIC scores were not useful in predicting the risk of infection after fixation of fractures. We propose a new score that incorporates fracture classification, American Society of Anesthesiologists classification, and body mass index as predictors of infection.

LEVEL OF EVIDENCE

Prognostic study, level II.

Reducing surgical site infection in arthroplasty of the lower limb: A multi-disciplinary approach

Objectives

To review the current best surgical practice and detail a multi-disciplinary approach that could further reduce joint replacement infection.

Methods

Review of relevant literature indexed in PubMed.

Results

Surgical site infection is a major complication following arthroplasty. Despite its rarity in contemporary orthopaedic practice, it remains difficult to treat and is costly in terms of both patient morbidity and long-term health care resources.

Conclusions

Emphasis on education of patients and all members of the health-care team and raising awareness in how to participate in preventative efforts is imperative.