Stephanie A. Mason

Hold the Pendulum: Rates of Acute Kidney Injury are Increased in Patients Who Receive Resuscitation Volumes Less than Predicted by the Parkland Equation.

Objective: To determine whether restrictive fluid resuscitation results in increased rates of acute kidney injury (AKI) or infectious complications. Background: Studies demonstrate that patients often receive volumes in excess of those predicted by the Parkland equation, with potentially detrimental sequelae. However, the consequences of under-resuscitation are not well-studied. Methods: Data were collected from a multicenter prospective cohort study. Adults with greater than 20% total burned surface area injury were divided into 3 groups on the basis of the pattern of resuscitation in the first 24 hours: volumes less than (restrictive), equal to, or greater than (excessive) standard resuscitation (4 to 6 cc/kg/% total burned surface area). Multivariable regression analysis was employed to determine the effect of fluid group on AKI, burn wound infections (BWIs), and pneumonia. Results: Among 330 patients, 33% received restrictive volumes, 39% received standard resuscitation volumes, and 28% received excessive volumes. The standard and excessive groups had higher mean baseline APACHE scores (24.2 vs 16, P < 0.05 and 22.3 vs 16, P < 0.05) than the restrictive group, but were similar in other characteristics. After adjustment for confounders, restrictive resuscitation was associated with greater probability of AKI [odds ratio (OR) 3.25, 95% confidence interval (95% CI) 1.18–8.94]. No difference in the probability of BWI or pneumonia among groups was found (BWI: restrictive vs standard OR 0.74, 95% CI 0.39–1.40, excessive vs standard OR 1.40, 95% CI 0.75–2.60, pneumonia: restrictive vs standard, OR 0.52, 95% CI 0.26–1.05; excessive vs standard, OR 1.12, 95% CI 0.58–2.14). Conclusions: Restrictive resuscitation is associated with increased AKI, without changes in infectious complications.

Laparoscopic Surgery for Adhesive Small Bowel Obstruction Is Associated With a Higher Risk of Bowel Injury: A Population-based Analysis of 8584 Patients

Objective: We set out to compare the incidence of bowel repair and/or resection in a large cohort of patients with adhesive small bowel obstruction (SBO) managed operatively. Background: Laparoscopic lysis of adhesions for adhesive SBO (aSBO) is becoming more common, yet might increase the risk of bowel injury given the distended and/or potentially compromised small bowel. Methods: We used administrative discharge data derived from a large geographic region, identifying patients who underwent surgery for their first episode of aSBO during 2005 to 2014. Procedure codes were used to determine the exposure: either an open approach or a laparoscopic approach (including procedures converted to open). The primary outcome was incidence of bowel intervention, defined as intraoperative enterotomy, suture repair of intestine, or bowel resection. We estimated the odds of bowel intervention after adjusting for patient and clinical factors. Results: A total of 8584 patients underwent operation for aSBO. Patients undergoing laparoscopic procedures were younger with fewer comorbid conditions. The rate of laparoscopic approaches increased more than 3-fold during the study period (4.3%–14.3%, P < 0.0001). The incidence of bowel intervention was 53.5% versus 43.4% in laparoscopic versus open procedures (P < 0.0001). After adjustment for potential confounders, the odds of bowel intervention among patients treated laparoscopically versus open was 1.6 (95% confidence interval: 1.4–1.9). Conclusions: Laparoscopic procedures for aSBO are associated with a greater likelihood of intervention for bowel injury and/or repair. This increase might be due to challenges inherent with laparoscopic approaches in patients with distended small bowel. Surgeons should approach laparoscopic lysis of adhesions with a higher level of awareness and use strategies to mitigate this risk.

Redefining "dead on arrival": Identifying the unsalvageable patient for the purpose of performance improvement.

BACKGROUND Significant variation exists across registries in the criteria used to identify patients with no chance of survival, with potential for profound impact on trauma center mortality. The purpose of this study was to identify the optimal case definition for the unsalvageable patient, for the purpose of exclusion from performance improvement (PI) endeavors. METHODS Data were derived from the American College of Surgeons’ Trauma Quality Improvement Program for 2012 to 2013. We proposed three potential case definitions for the unsalvageable patient: (1) no signs of life as determined by local providers (NSOL), (2) prehospital cardiac arrest (PHCA), and (3) a proxy definition (PROXY) based on presenting vital signs, defined as emergency department (ED) heart rate = 0, ED systolic blood pressure = 0, and Glasgow Coma Scale score motor component = 1. Case definitions were compared using standard predictive tests to determine specificity and positive predictive value (PPV) for in-hospital mortality. After the optimal definition was identified, hierarchical logistic regression was used to assess the impact of including unsalvageable patients on trauma center risk-adjusted mortality. The impact on trauma center performance was determined as change in outlier status and performance decile after exclusion of patients who met the optimal case definition. RESULTS During the study period, 223,643 patients met inclusion criteria across 192 trauma centers. Overall in-hospital mortality was 7.2%. The PROXY definition had excellent PPV for death, with less than 1% of patients meeting the PROXY criterion surviving. By contrast, NSOL and PHCA had PPVs low enough such that many of these patients went on to live (33% and 10%, respectively). After exclusion of patients who met the PROXY definition, 7% of trauma centers changed performance decile. This change was greatest for patients with penetrating injury and shock, with change in performance decile at 23% and 33% of centers, respectively. CONCLUSION The PROXY case definition has excellent predictive utility to identify patients who, based on presenting vital signs, will go on to die. PROXY should be used to exclude unsalvageable patients from PI endeavors.

Effectiveness of low-molecular-weight heparin versus unfractionated heparin to prevent pulmonary embolism following major trauma: A propensity-matched analysis.

BACKGROUND Pulmonary embolism (PE) is a leading cause of delayed mortality in patients with severe injury. While low-molecular-weight heparin (LMWH) is often favored over unfractionated heparin (UH) for thromboprophylaxis, evidence is lacking to demonstrate an effect on the occurrence of PE. This study compared the effectiveness of LMWH versus UH to prevent PE in patients following major trauma. METHODS Data for adults with severe injury who received thromboprophylaxis with LMWH or UH were derived from the American College of Surgeons Trauma Quality Improvement Program (2012–2015). Patients who died or were discharged within 5 days were excluded. Rates of PE were compared between propensity-matched LMWH and UH groups. Subgroup analyses included patients with blunt multisystem injury, penetrating truncal injury, shock, severe traumatic brain injury, and isolated orthopedic injury. A center-level analysis was performed to determine if practices with respect to choice of prophylaxis type influence hospital PE rates. RESULTS We identified 153,474 patients at 217 trauma centers who received thromboprophylaxis with LMWH or UH. Low-molecular-weight heparin was given in 74% of patients. Pulmonary embolism occurred in 1.8%. Propensity score matching yielded a well-balanced cohort of 75,920 patients. After matching, LMWH was associated with a significantly lower rate of PE compared with UH (1.4% vs. 2.4%; odds ratio, 0.56; 95% confidence interval, 0.50–0.63). This finding was consistent across injury subgroups. Trauma centers in the highest quartile of LMWH utilization (median LMWH use, 95%) reported significantly fewer PE compared with centers in the lowest quartile (median LMWH use, 39%; 1.2% vs. 2.0%; odds ratio, 0.59; 95% confidence interval, 0.48–0.74). CONCLUSIONS Thromboprophylaxis with LMWH (vs. UH) was associated with significantly lower risk of PE. Trauma centers favoring LMWH-based prophylaxis strategies reported lower rates of PE. Low-molecular-weight heparin should be the anticoagulant agent of choice for prevention of PE in patients with major trauma. LEVEL OF EVIDENCE Therapeutic study, level III.

Association Between Burn Injury and Mental Illness among Burn Survivors: A Population-Based, Self-Matched, Longitudinal Cohort Study

BACKGROUND Mental health disorders are prevalent before and after burn injury. However, the impact of burn injury on risk of subsequent mental health disorders is unknown. STUDY DESIGN We conducted a population-based, self-matched longitudinal cohort study using administrative data in Ontario, Canada between 2003 and 2011. All adults who survived to discharge after major burn injury were included, and all mental health-related emergency department visits were identified. Rate ratios (RRs) for mental health visits in the 3 years after burn, compared with the 3 years before, were estimated using negative binomial generalized estimating equations. RESULTS Among 1,530 patients with major burn injury, mental health visits were common both before (141 per 1,000 person years) and after (154 per 1,000 person years) injury. Mental health visits were most common in the 12 weeks immediately preceding injury. No significant difference in the overall visit rate was observed after burn (RR 0.97; 95% CI 0.78 to 1.20), although among patients with less than 1 pre-injury visit, mental health visits tripled (RR 3.72; 95% CI 2.70 to 5.14). Self-harm emergencies increased 2-fold (RR 1.95; 95% CI 1.15 to 3.33). CONCLUSIONS Mental health emergencies are prevalent among burn-injured patients. Although the overall rate of mental health visits is not increased after burn, the rate increases significantly among patients with one or fewer visits pre-injury. Self-harm risk increases significantly after burn injury, underscoring the need for screening and targeted interventions after discharge. An increased rate immediately before burn suggests an opportunity for injury prevention through mental healthcare.

The accuracy of burn diagnosis codes in health administrative data: A validation study

BACKGROUND Health administrative databases may provide rich sources of data for the study of outcomes following burn. We aimed to determine the accuracy of International Classification of Diseases diagnoses codes for burn in a population-based administrative database. METHODS Data from a regional burn centers clinical registry of patients admitted between 2006-2013 were linked to administrative databases. Burn total body surface area (TBSA), depth, mechanism, and inhalation injury were compared between the registry and administrative records. The sensitivity, specificity, and positive and negative predictive values were determined, and coding agreement was assessed with the kappa statistic. RESULTS 1215 burn center patients were linked to administrative records. TBSA codes were highly sensitive and specific for ≥10 and ≥20% TBSA (89/93% sensitive and 95/97% specific), with excellent agreement (κ, 0.85/κ, 0.88). Codes were weakly sensitive (68%) in identifying ≥10% TBSA full-thickness burn, though highly specific (86%) with moderate agreement (κ, 0.46). Codes for inhalation injury had limited sensitivity (43%) but high specificity (99%) with moderate agreement (κ, 0.54). Burn mechanism had excellent coding agreement (κ, 0.84). CONCLUSIONS Administrative data diagnosis codes accurately identify burn by burn size and mechanism, while identification of inhalation injury or full-thickness burns is less sensitive but highly specific.

Burned Adults Develop Profound Glucose Intolerance.

Objectives:Metabolic alterations after burn injury have been well described in children; however, in adult patients, glucose metabolism and insulin sensitivity are essentially unknown. We sought to characterize metabolic alterations and insulin resistance after burn injury and determine their magnitude and persistence at discharge. Design:Prospective, cohort study. Setting:Tertiary burn centre. Patients:Nondiabetic adults with an acute burn involving greater than or equal to 20% total body surface area. Interventions:An oral glucose tolerance test was administered at discharge. Measurements and Main Results:Glucose, insulin, and C-peptide levels were measured to derive surrogate measures of insulin resistance and &bgr;-cell function, including quantitative insulin sensitivity check index, homeostasis model assessment of &bgr;-cell function, homeostasis model assessment of insulin sensitivity, homeostasis model assessment of insulin resistance, and the composite whole-body insulin sensitivity index. Patients were grouped according to the degree of glucose tolerance: normal glucose tolerance, impaired fasting glucose/impaired glucose tolerance, or diabetes. Forty-five adults, 44 ± 15 years old and with 38% ± 14% total body surface area burned, underwent an oral glucose tolerance test at discharge. Median quantitative insulin sensitivity check index (0.348 [0.332–0.375]) and median homeostasis model assessment of insulin resistance (1.13 [0.69–1.45]) were abnormal, indicating insulin resistance and impaired insulin production at discharge. Two-thirds of patients (n = 28) met criteria for impaired fasting glucose/impaired glucose tolerance or diabetes. Conclusions:We have demonstrated that burn-injured adults remain hyperglycemic, are insulin resistant, and express defects in insulin secretion at discharge. Patients with lower burn severity (total body surface area, 20–30%) express similar metabolic alterations as patients with larger burns (total body surface area, ≥ 30%). Glucose tolerance testing at discharge offers an opportunity for early identification of burn patients who may be at high risk of prediabetes and diabetes. Our findings demonstrated that two-thirds of burn patients had some degree of glucose intolerance. With this in mind, surveillance of glucose intolerance post discharge should be considered. As hyperglycemia and insulin resistance are associated with poor outcomes, studies should focus on how long these profound alterations persist.

Burn center care reduces acute health care utilization after discharge: A population-based analysis of 1,895 survivors of major burn injury

Background. Improvements in survival after burns have resulted in more patients being discharged home after severe injury. However, the postdischarge health care needs of burn survivors are not well understood. We aimed to determine the rate and causes of unplanned presentation to acute care facilities in the 5 years after major burn injury. Methods. Data derived from several population‐based administrative databases were used to conduct a retrospective cohort study. All patients aged ≥16 years who survived to discharge after a major burn injury in 2003–2013 were followed for 1–5 years. All emergency department visits and unplanned readmissions were identified and classified by cause. Factors associated with emergency department visits were modeled using negative binomial generalized estimating equations. Factors associated with readmission were modeled using multivariable competing risk regression. Results. We identified 1,895 patients who survived to discharge; 68% of patients had at least one emergency department visit and 30% had at least one readmission. Five‐year mortality was 10%. The most common reason for both emergency department visits and readmissions was traumatic injury. After risk adjustment, patients who received their index care in a burn center experienced significantly less need for subsequent unplanned acute care, fewer emergency department visits (relative risk 0.61, 95% confidence interval, 0.52–0.72), and fewer hospital readmissions (hazard ratio 0.77, 95% confidence interval, 0.65–0.92). Conclusion. Acute health care utilization is frequent after burn injury and is most commonly related to traumatic injuries. Burn‐related events are uncommon beyond 30 days after discharge, suggesting low rates of burn recidivism. Patients treated at burn centers have significantly reduced unplanned health care utilization after their injury.

Trends in the epidemiology of major burn injury among hospitalized patients: A population-based analysis

BACKGROUND Burn-related mortality has decreased significantly over the past several decades. Although often attributed in part to regionalization of burn care, this has not been evaluated at the population level. METHODS We conducted a retrospective, population-based cohort study of all patients with 20% or higher total body surface area burn injury in Ontario, Canada. Adult (≥16 years) patients injured between 2003 and 2013 were included. Deaths in the emergency department were excluded. Logistic generalized estimating equations were used to estimate risk-adjusted 30-day mortality. Mortality trends were compared at burn and nonburn centers. RESULTS Seven hundred seventy-two patients were identified at 84 centers (2 burn, 82 nonburn). Patients were 74% (n = 570) male, of median age 46 (interquartile range [IQR], 35–60) years and median total body surface area 35% (IQR, 25–45). Mortality at 30 days was 19% (n = 149). The proportion of patients treated at a burn center increased from 57% to 71% between 2003 and 2013 (p = 0.07). Average risk-adjusted 30-day mortality rates decreased over time; there were significantly reduced odds of death in 2010 to 2013 compared with 2003 to 2006 (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.25–0.61). Burn centers exhibited significantly reduced mortality from 2003–2006 to 2010–2013 (OR, 0.36; 95% CI, 0.34–0.38) compared with nonburn centers (OR, 0.41; 95% CI, 0.13–1.24). CONCLUSION Mortality rates have decreased over time; significant improvements have occurred at burn centers, whereas mortality rates at nonburn centers vary widely. A high proportion of patients continue to receive care outside of burn centers. These data suggest that there are further opportunities to regionalize burn care and in so doing, potentially lower burn-related mortality. LEVEL OF EVIDENCE Epidemiological study, level III; Therapy, level IV.

The influence of substance misuse on clinical outcomes following burn

INTRODUCTION Ongoing increases in the prevalence of substance misuse among burn-injured patients necessitate a contemporary analysis of the association between substance misuse and clinical outcomes in burn-injured adults. METHODS We conducted a retrospective cohort study of 1199 patients admitted to a regional burn center. History of substance misuse was derived from a prospective clinical registry and categorized as alcohol, illicit drug, or both. The primary outcome was hospital length of stay; association of substance misuse and inpatient complications were secondary outcomes. Multivariable logistic regression was used to model the association between categories of substance misuse and each outcome, adjusting for patient and injury characteristics. RESULTS The incidence of substance misuse was 34% overall. After adjustment for patient and injury characteristics, drug misuse was associated with a significantly longer length of stay (RR 1.12; 95% CI 1.00-1.25), as was alcohol misuse (RR 1.32; 95% CI 1.14-1.52), and drug/alcohol misuse (RR 1.34; 95% CI 1.16-1.56). Drug/alcohol misuse was associated with significantly higher rates of bacteremia (OR 3.84; 95% CI 1.83-8.04) and sepsis (OR 2.50; CI 1.13-5.53). CONCLUSIONS A history of substance misuse is associated with an increased risk of inpatient complications and longer hospital stay. Providers should be cognizant of increased complications in this cohort with a view to improving outcomes.