Use of Dermal Regenerative Templates for Burns.

Autologous skin grafting has permitted survival and restoration of function in burn injuries of ever larger total body surface area (TBSA) sizes. However, the goal of replacing "like with like" skin structures is often impossible because full-thickness donor harvesting requires primary closure at the donor site for it to heal. Split-thickness skin grafting (STSG), on the other hand, only harvests part of the dermis at the donor site, allowing it to re-epithelialize on its own. The development of the first dermal regenerative template (DRT) in the late 1970s represented a major advance in tissue engineering that addresses the issue of insufficient dermal replacement when STSGs are applied to the full-thickness defect. This review aims to provide an overview of currently available DRTs in burn management from a clinician's perspective. It focuses on the main strengths and pitfalls of each product and provides clinical pearls based on clinical experience and evidence.

Acute and long-term clinical, neuropsychological and return-to-work sequelae following electrical injury: a retrospective cohort study.

OBJECTIVE: To determine acute and long-term clinical, neuropsychological, and return-to-work (RTW) effects of electrical injuries (EIs). This study aims to further contrast sequelae between low-voltage and high-voltage injuries (LVIs and HVIs). We hypothesise that all EIs will result in substantial adverse effects during both phases of management, with HVIs contributing to greater rates of sequelae. DESIGN: Retrospective cohort study evaluating EI admissions between 1998 and 2015. SETTING: Provincial burn centre and rehabilitation hospital specialising in EI management. PARTICIPANTS: All EI admissions were reviewed for acute clinical outcomes (n=207). For long-term outcomes, rehabilitation patients, who were referred from the burn centre (n=63) or other burn units across the province (n=65), were screened for inclusion. Six patients were excluded due to pre-existing psychiatric conditions. This cohort (n=122) was assessed for long-term outcomes. Median time to first and last follow-up were 201 (68-766) and 980 (391-1409) days, respectively. OUTCOME MEASURES: Acute and long-term clinical, neuropsychological and RTW sequelae. RESULTS: Acute clinical complications included infections (14%) and amputations (13%). HVIs resulted in greater rates of these complications, including compartment syndrome (16% vs 4%, p=0.007) and rhabdomyolysis (12% vs 0%, p<0.001). Rates of acute neuropsychological sequelae were similar between voltage groups. Long-term outcomes were dominated by insomnia (68%), anxiety (62%), post-traumatic stress disorder (33%) and major depressive disorder (25%). Sleep difficulties (67%) were common following HVIs, while the LVI group most frequently experienced sleep difficulties (70%) and anxiety (70%). Ninety work-related EIs were available for RTW analysis. Sixty-one per cent returned to their preinjury employment and 19% were unable to return to any form of work. RTW rates were similar when compared between voltage groups. CONCLUSIONS: This is the first investigation to determine acute and long-term patient outcomes post-EI as a continuum. Findings highlight substantial rates of neuropsychological and social sequelae, regardless of voltage. Specialised and individualised early interventions, including screening for mental health concerns, are imperative to improvingoutcomes of EI patients.

Increased Rate of Long-term Mortality Among Burn Survivors: A Population-based Matched Cohort Study.

OBJECTIVE: To estimate long-term mortality following major burn injury compared with matched controls. SUMMARY BACKGROUND DATA: The effect of sustaining a major burn injury on long-term life expectancy is poorly understood. METHODS: Using health administrative data, all adults who survived to discharge after major burn injury between 2003 and 2013 were matched to between 1 and 5 uninjured controls on age, sex, and the extent of both physical and psychological comorbidity. To account for socioeconomic factors such as residential instability and material deprivation, we also matched on marginalization index. The primary outcome was 5-year all-cause mortality, and all patients were followed until death or March 31, 2014. Cumulative mortality estimates were estimated using the Kaplan-Meier method. Cox proportional hazards modeling was used to estimate the association of burn injury with mortality. RESULTS: In total, 1965 burn survivors of mean age 44 (standard deviation 17) years with median total body surface area burn of 15% [interquartile range (IQR) 5-15] were matched to 8671 controls and followed for a median 5 (IQR 2.5-8) years. Five-year mortality was significantly greater among burn survivors (11 vs 4%, P < 0.001). The hazard ratio was greatest during the first year (4.15, 95% CI 3.17-5.42), and declined each year thereafter, reaching 1.65 (95% CI 1.02-2.67) in the fifth year after discharge. Burn survivors had increased mortality related to trauma (mortality rate ratio, MRR 9.8, 95% CI 5-19) and mental illness (MRR 9.1, 95% CI 4-23). CONCLUSIONS: Burn survivors have a significantly higher rate of long-term mortality than matched controls, particularly related to trauma and mental illness. Burn follow-up should be focused on injury prevention, mental healthcare, and detection and treatment of new disease.

Association Between Emergency Medical Service Response Time and Motor Vehicle Crash Mortality in the United States.

Importance: Motor vehicle crashes (MVCs) are a leading public health concern. Emergency medical service (EMS) response time is a modifiable, system-level factor with the potential to influence trauma patient survival. The relationship between EMS response time and MVC mortality is unknown. Objectives: To measure the association between EMS response times and MVC mortality at the population level across US counties. Design, Setting, and Study Population: This population-based study included MVC-related deaths in 2268 US counties, representing an estimated population of 239 464 121 people, from January 1, 2013, through December 31, 2015. Data were analyzed from October 1, 2017, through April 30, 2018. Exposure: The median EMS response time to MVCs within each county (county response time), derived from data collected by the National Emergency Medical Service Information System. Main Outcomes and Measures: The county rate of MVC-related death, calculated using crash fatality data recorded in the Fatality Analysis Reporting System of the National Highway Traffic Safety Administration. Results: During the study period, 2 214 480 ambulance responses to MVCs were identified (median, 229 responses per county [interquartile range (IQR), 73-697 responses per county]) in 2268 US counties. The median county response time was 9 minutes (IQR, 7-11) minutes. Longer response times were significantly associated with higher rates of MVC mortality (≥12 vs <7 minutes; mortality rate ratio, 1.46; 95% CI, 1.32-1.61) after adjusting for measures of rurality, on-scene and transport times, access to trauma resources, and traffic safety laws. This finding was consistent in both rural/wilderness and urban/suburban settings, where a significant proportion of MVC fatalities (population attributable fraction: rural/wilderness, 9.9%; urban/suburban, 14.1%) were associated with prolonged response times (defined by the median value, ≥10 minutes and ≥7 minutes, respectively). Conclusions and Relevance: Among 2268 US counties, longer EMS response times were associated with higher rates of MVC mortality. A significant proportion of MVC-related deaths were associated with prolonged response times in both rural/wilderness and urban/suburban settings. These findings suggest that trauma system-level efforts to address regional disparities in MVC mortality should evaluate EMS response times as a potential contributor.

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.

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 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 center's 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.

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.

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.

Timing of Pharmacologic Venous Thromboembolism Prophylaxis in Severe Traumatic Brain Injury: A Propensity-Matched Cohort Study.

BACKGROUND: Patients with severe traumatic brain injury (sTBI) are at high risk for developing venous thromboembolism (VTE). Nonetheless, pharmacologic VTE prophylaxis is often delayed out of concern for precipitating extension of intracranial hemorrhage (ICH). The purpose of this study was to compare the effectiveness of early vs late VTE prophylaxis in patients with sTBI, and to characterize the risk of subsequent ICH-related complication. STUDY DESIGN: Adults with isolated sTBI (head Abbreviated Injury Scale score ≥3 and total Glasgow Coma Scale score ≤8) who received VTE prophylaxis with low-molecular-weight or unfractionated heparin were derived from the American College of Surgeons Trauma Quality Improvement Program (2012 to 2014). Patients were divided into EP (<72 hours) or LP (≥72 hours) groups. Propensity score matching was used to minimize selection bias. The primary end point was VTE (pulmonary embolism or deep vein thrombosis). Secondary outcomes were defined as late neurosurgical intervention (≥72 hours) or death. RESULTS: We identified 3,634 patients with sTBI. Early prophylaxis was given in 43% of patients. Higher head injury severity, presence of ICH, and early neurosurgery were associated with late prophylaxis. Propensity score matching yielded a well-balanced cohort of 2,468 patients. Early prophylaxis was associated with lower rates of both pulmonary embolism (odds ratio = 0.48; 95% CI, 0.25-0.91) and deep vein thrombosis (odds ratio = 0.51; 95% CI, 0.36-0.72), but no increase in risk of late neurosurgical intervention or death. CONCLUSIONS: In this observational study of patients with sTBI, early initiation of VTE prophylaxis was associated with decreased risk of pulmonary embolism and deep vein thrombosis, but no increase in risk of late neurosurgical intervention or death. Early prophylaxis may be safe and should be the goal for each patient in the context of appropriate risk stratification.

A biomechanical comparison of four different cementless press-fit stems used in revision surgery for total knee replacements.

Few biomechanical studies exist on femoral cementless press-fit stems for revision total knee replacement (TKR) surgeries. The aim of this study was to compare the mechanical quality of the femur-stem interface for a series of commercially available press-fit stems, because this interface may be a 'weak link' which could fail earlier than the femur-TKR bond itself. Also, the femur-stem interface may become particularly critical if distal femur bone degeneration, which may necessitate or follow revision TKR, ever weakens the femur-TKR bond itself. The authors implanted five synthetic femurs each with a Sigma Short Stem (SSS), Sigma Long Stem (SLS), Genesis II Short Stem (GSS), or Genesis II Long Stem (GLS). Axial stiffness, lateral stiffness, 'offset load' torsional stiffness, and 'offset load' torsional strength were measured with a mechanical testing system using displacement control. Axial (range = 1047-1461 N/mm, p = 0.106), lateral (range = 415-462 N/mm, p = 0.297), and torsional (range = 115-139 N/mm, p > 0.055) stiffnesses were not different between groups. The SSS had higher torsional strength (863 N) than the other stems (range = 167-197 N, p < 0.001). Torsional failure occurred by femoral 'spin' around the stem's long axis. There was poor linear correlation between the femur-stem interface area versus axial stiffness (R = 0.38) and torsional stiffness (R = 0.38), and there was a moderate linear correlation versus torsional strength (R = 0.55). Yet, there was a high inverse linear correlation between interfacial surface area versus lateral stiffness (R = 0.79), although this did not result in a statistical difference between stem groups (p = 0.297). These press-fit stems provide equivalent stability, except that the SSS has greater torsional strength.

The neurobiology of adaptive learning in reading: a contrast of different training conditions.

fMRI was used to investigate the separate influences of orthographic, phonological, and semantic processing on the ability to learn new words and the cortical circuitry recruited to subsequently read those words. In a behavioral session, subjects acquired familiarity for three sets of pseudowords, attending to orthographic, phonological, or (learned) semantic features. Transfer effects were measured in an event-related fMRI session as the subjects named trained pseudowords, untrained pseudowords, and real words. Behaviorally, phonological and semantic training resulted in better learning than did orthographic training. Neurobiologically, orthographic training did not modulate activation in the main reading regions. Phonological and semantic training yielded equivalent behavioral facilitation but distinct functional activation patterns, suggesting that the learning resulting from these two training conditions was driven by different underlying processes. The findings indicate that the putative ventral visual word form area is sensitive to the phonological structure of words, with phonologically analytic processing contributing to the specialization of this region.