Joint Theater Trauma System Implementation of Burn Resuscitation Guidelines Improves Outcomes in Severely Burned Military Casualties

Fluid Management, Intra-Abdominal Hypertension and the Abdominal Compartment Syndrome: A Narrative Review

BACKGROUND

General pathophysiological mechanisms regarding associations between fluid administration and intra-abdominal hypertension (IAH) are evident, but specific effects of type, amount, and timing of fluids are less clear.

OBJECTIVES

This review aims to summarize current knowledge on associations between fluid administration and intra-abdominal pressure (IAP) and fluid management in patients at risk of intra-abdominal hypertension and abdominal compartment syndrome (ACS).

METHODS

We performed a structured literature search from 1950 until May 2021 to identify evidence of associations between fluid management and intra-abdominal pressure not limited to any specific study or patient population. Findings were summarized based on the following information: general concepts of fluid management, physiology of fluid movement in patients with intra-abdominal hypertension, and data on associations between fluid administration and IAH.

RESULTS

We identified three randomized controlled trials (RCTs), 38 prospective observational studies, 29 retrospective studies, 18 case reports in adults, two observational studies and 10 case reports in children, and three animal studies that addressed associations between fluid administration and IAH. Associations between fluid resuscitation and IAH were confirmed in most studies. Fluid resuscitation contributes to the development of IAH. However, patients with IAH receive more fluids to manage the effect of IAH on other organ systems, thereby causing a vicious cycle. Timing and approach to de-resuscitation are of utmost importance, but clear indicators to guide this decision-making process are lacking. In selected cases, only surgical decompression of the abdomen can stop deterioration and prevent further morbidity and mortality.

CONCLUSIONS

Current evidence confirms an association between fluid resuscitation and secondary IAH, but optimal fluid management strategies for patients with IAH remain controversial.

BurnCare tablet trainer to enhance burn injury care and treatment

BACKGROUND

Applied Research Associates (ARA) and the United States Army Institute of Surgical Research (USAISR) have been developing a tablet-based simulation environment for burn wound assessment and burn shock resuscitation. This application aims to supplement the current gold standard in burn care education, the Advanced Burn Life Support (ABLS) curriculum.

RESULTS

Subject matter experts validate total body surface area (TBSA) identification and analysis and show that the visual fidelity of the tablet virtual patients is consistent with real life thermal injuries. We show this by noting that the error between their burn mapping and the actual patient burns was sufficiently less than that of a random sample population. Statistical analysis is used to confirm this hypothesis. In addition a full body physiology model developed for this project is detailed. Physiological results, and responses to standard care treatment, are detailed and validated. Future updates will include training modules that leverage this model.

CONCLUSION

We have created an accurate, whole-body model of burn TBSA training experience in Unreal 4 on a mobile platform, provided for free to the medical community. We hope to provide learners with more a realistic experience and with rapid feedback as they practice patient assessment, intervention, and reassessment.

Management of severe thermal burns in the acute phase in adults and children

OBJECTIVES

To provide recommendations to facilitate the management of severe thermal burns during the acute phase in adults and children.

DESIGN

A committee of 20 experts was asked to produce recommendations in six fields of burn management, namely, (1) assessment, admission to specialised burns centres, and telemedicine; (2) haemodynamic management; (3) airway management and smoke inhalation; (4) anaesthesia and analgesia; (5) burn wound treatments; and (6) other treatments. At the start of the recommendation-formulation process, a formal conflict-of-interest policy was developed and enforced throughout the process. The entire process was conducted independently of any industry funding. The experts drew up a list of questions that were formulated according to the PICO model (Population, Intervention, Comparison, and Outcomes). Two bibliography experts per field analysed the literature published from January 2000 onwards using predefined keywords according to PRISMA recommendations. The quality of data from the selected literature was assessed using GRADE® methodology. Due to the current paucity of sufficiently powered studies regarding hard outcomes (i.e. mortality), the recommendations are based on expert opinion.

RESULTS

The SFAR guidelines panel generated 24 statements regarding the management of acute burn injuries in adults and children. After two scoring rounds and one amendment, strong agreement was reached for all recommendations.

CONCLUSION

Substantial agreement was reached among a large cohort of experts regarding numerous strong recommendations to optimise the management of acute burn injuries in adults and children.

Trend Analysis of Current Modalities for Monitoring Fluid Therapy in Patients With Large Burns: Echoing the Call for Better Resuscitation Indices

The aim of this study was to investigate whether current standards at our institution have effectively monitored resuscitations of severely burned patients during the first 48 hours postburn. Demographics, injuries assessed by TBSA and full thickness (FT), and resuscitation volumes (lactated Ringer's [LR]) were compared for all patients and those who died or survived. Means and standard deviations of hourly indices (urinary output [UOP], lactate [LAC], base excess [BE]) vs LR were analyzed. Waveforms, four-quadrant concordance, and correlation were also employed to compare the trending abilities (hourly changes [∆]) of aforementioned variables vs LR. A total of 203 patients were included in the analysis. Of these patients, 71 (35%) died, and 50 (25%) had inhalation injuries. Mean age and weight were 47 ± 19 years and 87 ± 18 kg, respectively. Mean TBSA burned was 41 ± 20%, with a mean FT of 18 ± 24%. Importantly, normalized waveform plots demonstrated the inability of UO, LAC, and BE to follow hourly changes in LR. Correlation of these variables was weak (r>>-1). This was confirmed by concordance plots. Slopes in all groups demonstrated that UOP was a better resuscitative monitor than LAC or BE. ∆UOP responded to ∆LR better in patients who survived than died. Reliance on hourly UOP as the sole index of optimal resuscitation is not supported. This study echoed the call for better resuscitation indices.

Quantifying the effects of wound healing risk and potential on clinical measurements and outcomes of severely burned patients: A data-driven approach

INTRODUCTION

Given recent advances in computational power, the goal of this study was to quantify the effects of wound healing risk and potential on clinical measurements and outcomes of severely burned patients, with the hope of providing more insight on factors that affect wound healing.

METHODS

This retrospective study involved patients who had at least 10% TBSA% "burned" and three burn mappings each. To model risk to wounds, we defined the variable θ, a hypothetical threshold for TBSA% "open wound" used to demarcate "low-risk" from "high-risk" patients. Low-risk patients denoted those patients whose actual TBSA% "open wound" ≤θ, whereas high-risk patients denoted those patients whose actual TBSA% "open wound" >θ. To consider all possibilities of risk, 100 sub analyses were performed by (1) varying θ from 100% to 1% in decrements of 1%, (2) grouping all patients as either "low-risk" or "high-risk" for each θ, and (3) comparing all means and deviations of variables and outcomes between the two groups for each θ. Hence, this study employed a data-driven approach to capture trends in clinical measurements and outcomes. Plots and tables were also obtained.

RESULTS

For 303 patients, median age and weight were 43 [29-59] years and 85 [72-99]kg, respectively. Mean TBSA% "burned" was 25 [17-39] %, with a full-thickness burn of 4 [0-15] %. Average crystalloid volumes were 4.25±2.27mL/kg/TBSA% "burned" in the first 24h. Importantly, for high-risk patients, decreasing θ was matched by significant increases in PaO2-FiO2 ratio, platelet count, Glasgow coma score (GCS), and MAP. On the other hand, increasing their risk θ was also matched by significant increases in creatinine, bilirubin, lactate, blood, estimated blood loss, and 24-h and total fluid volumes. As expected, for low-risk patients, clinical measurements were more stable, despite decreasing or increasing θ. At a θ of 80%, statistical tests indicated much disparity between high-risk and low-risk patients for TBSA% "burned", full thickness burn, bilirubin (1.66±1.16mg/dL versus 0.83±0.65mg/dL, p=0.005), GCS (7±2 versus 12±3, p<0.001), MAP (42±22mm Hg versus 59±22mm Hg, p=0.004), 24-h blood, estimated blood loss, 24-h fluid, total fluid, and ICU length of stay (81±113 days versus 24±27 days, p=0.002). These differences were all statistically significant and remained significant down to θ=10%.

CONCLUSION

Wound healing risk and potential may be forecasted by many different clinical measurements and outcomes and has many implications on multi-organ function. Future work will be needed to further explain and understand these effects, in order to facilitate development of new predictive models for wound healing.

Early hypoalbuminemia is associated with 28-day mortality in severely burned patients: A retrospective cohort study

BACKGROUND

Hypoalbuminemia is a frequent condition in the first 24 h after a severe burn injury and is associated with worse outcomes.

METHODOLOGY

We investigated the relation between very early hypoalbuminemia (<6 h after admission) and clinical outcome in a retrospective cohort admitted to our unit for severe burn injuries between 2012 and 2017.

RESULTS

73 severely burned patients were included, with a delay of admission of 3 (2-4) h. In a context of early exogenous supply of albumin, admission and 4H Albuminemia (Alb4 h) were significantly lower in deceased patients (respectively, 34 (29-37) vs 27 (23-30) g/l; p = 0.009 and 27 (24-32) vs 21 (17-27) g/l; p = 0.022) whereas albuminemia ≥6 h were not. The best threshold value of Alb4 h to discriminate 28-day mortality was 23 g/l. Patients with an Alb4 h < 23 g/l had a higher 28-day mortality than patients with an Alb4 h ≥ 23 g/l (42% vs 11%; p = 0.003); adjusted OR = 4.47 (95% CI 1.15-17.36); p = 0.03.

CONCLUSION

In severely burned patients receiving early albumin supply, early hypoalbuminemia is associated with higher mortality whereas later albuminemia (≥6 h) is not. Exploration of whether early albumin infusion (8-12 h post injury) may alter clinical outcome is warranted.

Relationship Between Burn Wound Location and Outcomes in Severely Burned Patients: More Than Meets the Size

We hypothesized that burn location plays an important role in wound healing, mortality, and other outcomes and conducted the following study to test this multifold hypothesis. We conducted a study to retrospectively look at patients with burns ≥10% TBSA. Demographics, TBSA, partial/full thickness burns (PT/FT) in various wound locations, fluids, inhalation injury, mortality, ICU duration, and hospital duration were considered. Initial wound healing rates (%/d) were also calculated as a slope from the time of the first mapping of open wound size to the time of the third mapping of open wound size. Multivariate logistic regression and operating curves were used to measure mortality prediction performance. All values were expressed as median [interquartile range]. The mortality rate for 318 patients was 17% (54/318). In general, patients were 43 years [29, 58 years] old and had a TBSA of 25% [17, 39%], PT of 16% [10, 25%], and FT of 4% [0, 15%]. Between patients who lived and did not, age, TBSA, FT, 24-hour fluid, and ICU duration were statistically different (P < .001). Furthermore, there were statistically significant differences in FT head (0% [0, 0%] vs 0% [0, 1%], P = .048); FT anterior torso (0% [0, 1%] vs 1% [0, 4%], P < .001); FT posterior torso (0% [0, 0%] vs 0% [0, 4%], P < 0.001); FT upper extremities (0% [0, 3%] vs 2% [0, 11%], P < .001); FT lower extremities (0% [0, 2%] vs 6% [0, 17%], P < .001); and FT genitalia (0% [0, 0%] vs 0% [0, 2%], P < .001). Age, presence of inhalation injury, PT/FT upper extremities, and FT lower extremities were independent mortality predictors and per unit increases of these variables were associated with an increased risk for mortality (P < .05): odds ratio of 1.09 (95% confidence interval [CI] = 1.61–1.13; P < .001) for mean age; 2.69 (95% CI = 1.04–6.93; P = .041) for inhalation injury; 1.14 (95% CI = 1.01–1.27; P = .031) for mean PT upper extremities; 1.26 (95% CI = 1.11–1.42; P < .001) for mean FT upper extremities; and 1.07 (95% CI = 1.01–1.12; P = .012) for mean FT lower extremities. Prediction of mortality was better using specific wound locations (area under the curve [AUC], AUC of 0.896) rather than using TBSA and FT (AUC of 0.873). Graphs revealed that initial healing rates were statistically lower and 24-hour fluids and ICU length of stay were statistically higher in patients with FT upper extremities than in patients without FT extremities (P < .001). Burn wound location affects wound healing and helps predict mortality and ICU length of stay and should be incorporated into burn triage strategies to enhance resource allocation or stratify wound care.

Plasma protein C levels are directly associated with better outcomes in patients with severe burns

Protein C circulates in human plasma to regulate inflammation and coagulation. It has shown a crucial role in wound healing in animals, and low plasma levels predict the presence of a wound in diabetic patients. However, no detailed study has measured protein C levels in patients with severe burns over the course of a hospital admission. A severe burn is associated with dysfunction of inflammation and coagulation as well as a significant risk of morbidity and mortality. The current methods of burn assessment have shortcomings in reliability and have limited prognostic value. The discovery of a biomarker that estimates burn severity and predicts clinical events with greater accuracy than current methods may improve management, resource allocation and patient counseling. This is the first study to assess the potential role of protein C as a biomarker of burn severity. We measured the plasma protein C levels of 86 patients immediately following a severe burn, then every three days over the first three weeks of a hospital admission. We also analysed the relationships between burn characteristics, blood test results including plasma protein C levels and clinical events. We used a primary composite outcome of increased support utilisation defined as: a mean intravenous fluid administration volume of five litres or more per day over the first 72 h of admission, a length of stay in the intensive care unit of more than four days, or greater than four surgical procedures during admission. The hypothesis was that low protein C levels would be negatively associated with increased support utilisation. At presentation to hospital after a severe burn, the mean plasma protein C level was 76 ± 20% with a range of 34-130% compared to the normal range of 70-180%. The initial low can be plausibly explained by impaired synthesis, increased degradation and excessive consumption of protein C following a burn. Levels increased gradually over six days then remained at a steady-state until the end of the inpatient study period, day 21. A multivariable regression model (Nagelkerke's R² = 0.83) showed that the plasma protein C level on admission contributed the most to the ability of the model to predict increased support utilisation (OR = 0.825 (95% CI = 0.698-0.977), P = 0.025), followed by burn size (OR = 1.252 (95% CI = 1.025-1.530), P = 0.027), burn depth (partial thickness was used as the reference, full thickness OR = 80.499 (1.569-4129.248), P = 0.029), and neutrophil count on admission (OR = 1.532 (95% CI = 0.950-2.473), P = 0.08). Together, these four variables predicted increased support utilisation with 93.2% accuracy, 83.3% sensitivity and 97.6% specificity. However if protein C values were disregarded, only 49.5% of the variance was explained, with 82% accuracy, 63% sensitivity and 91.5% specificity. Thus, protein C may be a useful biomarker of burn severity and study replication will enable validation of these novel findings.

Burn Casualty Care in the Deployed Setting

Management of wartime burn casualties can be very challenging. Burns frequently occur in the setting of other blunt and penetrating injuries. This clinical practice guideline provides a manual for burn injury assessment, resuscitation, wound care, and specific scenarios including chemical and electrical injuries in the deployed or austere setting. The clinical practice guideline also reviews considerations for the definitive care of local national patients, including pediatric patients, who are unable to be evacuated from theater. Medical providers are encouraged to contact the US Army Institute of Surgical Research (USAISR) Burn Center when caring for a burn casualty in the deployed setting.

Positive cumulative fluid balance at 72h is associated with adverse outcomes following acute pediatric thermal injury

OBJECTIVE

To determine the association between fluid resuscitation volume following pediatric burn injury and impact on outcomes.

METHODS

A retrospective chart review of pediatric patients (0-18 years) sustaining ≥15% TBSA burn, admitted to an American Burn Association verified pediatric burn center from 2010 to 2015.

RESULTS

Twenty-seven patients met inclusion criteria and had complete data available for analysis. Fifteen (56%) patients received greater than 6ml/kg/total body surface area burn in first 24h and twelve (44%) patients received less than 6ml/kg/percent total body surface area burn in first 24h. There were no differences between groups in median number of mechanical ventilator days (4 vs 8, p=0.96), intensive care unit length of stay (10 vs 13.5, p=0.75), or hospital length of stay (37 vs 37.5, p=0.56). Secondary analysis revealed that patients with a higher mean cumulative fluid overload (>253ml/kg, n=16) had larger burn size, higher injury severity scores, and were more likely to receive mechanical ventilation and invasive support devices. Controlling for burn size, odds of longer PICU length of stay and duration of mechanical ventilation were 20.33 [95% CI (1.7-235.6) p=0.02] and 27.9 [95% CI (2.1-364.7) p=0.01], respectively, among patients with a high cumulative fluid overload on day 3 compared to low cumulative fluid overload.

CONCLUSIONS

Resuscitation volume in the first 24h was not associated with adverse outcomes. Persistent cumulative fluid overload at day 3 and beyond was independently associated with adverse outcomes.

Albumin in Burn Shock Resuscitation: A Meta-Analysis of Controlled Clinical Studies

Critical appraisal of outcomes after burn shock resuscitation with albumin has previously been restricted to small relatively old randomized trials, some with high risk of bias. Extensive recent data from nonrandomized studies assessing the use of albumin can potentially reduce bias and add precision. The objective of this meta-analysis was to determine the effect of burn shock resuscitation with albumin on mortality and morbidity in adult patients. Randomized and nonrandomized controlled clinical studies evaluating mortality and morbidity in adult patients receiving albumin for burn shock resuscitation were identified by multiple methods, including computer database searches and examination of journal contents and reference lists. Extracted data were quantitatively combined by random-effects meta-analysis. Four randomized and four nonrandomized studies with 688 total adult patients were included. Treatment effects did not differ significantly between the included randomized and nonrandomized studies. Albumin infusion during the first 24 hours showed no significant overall effect on mortality. However, significant statistical heterogeneity was present, which could be abolished by excluding two studies at high risk of bias. After those exclusions, albumin infusion was associated with reduced mortality. The pooled odds ratio was 0.34 with a 95% confidence interval of 0.19 to 0.58 (P < .001). Albumin administration was also accompanied by decreased occurrence of compartment syndrome (pooled odds ratio, 0.19; 95% confidence interval, 0.07–0.50; P < .001). This meta-analysis suggests that albumin can improve outcomes of burn shock resuscitation. However, the scope and quality of current evidence are limited, and additional trials are needed.

Burn State of the Science: Fluid Resuscitation

Recognition of fluid creep has driven a large amount of the scientific investigation in the area of acute fluid resuscitation for burn patients. The role of colloids in ameliorating fluid creep is controversial, despite the fact that a fluid-sparing effect of colloids has been recognized for some time. All but one of the available prospective studies using colloids are more than a decade old, and a modern randomized controlled trial (RCT) comparing crystalloids to colloids is long overdue. While urinary output continues to be the main endpoint for fluid titration, there has been a moderate amount of interest in the use of transpulmonary thermodilution to guide fluid resuscitation. The available studies have found that transpulmonary thermodilution has had an inconsistent effect on limiting fluid resuscitation volumes and improving clinical outcomes. Computerized Decision Support Systems show great promise in optimizing fluid titration and reducing fluid resuscitation volumes, and an RCT comparing Computerized Decision Support Systems with conventional titration approaches will be the important next step. Use of high-dose vitamin C (ascorbic acid) has become a popular approach to limit fluid resuscitation volumes and edema formation, but it has been investigated in only two clinical studies: one a pseudo-randomized prospective study and the other a retrospective study. Improvements in clinical outcome have not been convincingly demonstrated, and concerns persist surrounding the possibility of induction of an osmotic diuresis, leading to intravascular volume depletion. An RCT is urgently required to evaluate high-dose vitamin C as an adjunct to crystalloid resuscitation compared with the use of crystalloids alone.

Presenting hypertension, burn injury, and mortality in combat casualties

INTRODUCTION

The effect of presenting hypertension is poorly studied in combat casualties. We hypothesized that elevated mean arterial pressure (MAP) on presentation to combat hospitals would be associated with poor outcomes.

METHODS

Data was obtained from the Department of Defense Trauma Registry and the Armed Forces Medical Examiner System. Variables analyzed included presenting vital signs to Role II-III military theater hospital, demographic variables, injury severity score (ISS), location and mechanism of injury, presence of traumatic brain injury (TBI), acute kidney injury (AKI), and mortality. Patients were stratified by decile of MAP and logistic regression analysis was employed to adjust for confounders.

RESULTS

A total of 4072 subjects injured from February 2002 to February 2011 were identified. Compared to patients in the middle deciles of presenting MAP, patients in the highest and lowest MAP deciles were the only groups that demonstrated a higher mortality on univariate analysis (OR 2.06, 95% CI 1.16-2.31 and OR 2.86, 95% CI 1.76-4.67, respectively), and this relationship persisted after adjustment for ISS, HR, temperature, presence of burn injury, TBI, and AKI. Burn injury was associated with mortality in the full multivariate analysis. However, further analysis limited to patients without burn injury did not demonstrate an association between high MAP and mortality (OR 0.84, 95% CI 0.36-1.99; p=0.70). Conversely, when limited to patients with burn injury, high MAP was associated with mortality (OR 3.78, 95% CI 1.74-8.20; p=0.001).

CONCLUSION

The relationship between mortality and presenting MAP appears to be U-shaped, demonstrating increased mortality in the lowest and highest deciles. However, mortality in the highest MAP decile appears to be limited to casualties with associated burn injury, even after adjustment for TBI, AKI, and ISS, which takes into account the severity of the burn injury. Physicians should recognize that burn patients presenting with an elevated MAP are at an increased risk for poor outcomes.

LEVEL OF EVIDENCE

III.

Clinical practice guideline adherence during Operation Inherent Resolve

BACKGROUND

The Joint Trauma System (JTS) clinical practice guidelines (CPGs) contributed to the decrease in battlefield mortality over the past 15 years. However, it is unknown to what degree the guidelines are being followed in current military operations.

METHODS

A retrospective review was performed of all patients treated at three separate US Army Role II facilities during the first 10 months of Operation Inherent Resolve in Iraq. Charts were reviewed for patient demographics, clinical care, and outcomes. Charts were also reviewed for compliance with JTS CPGs and Tactical Combat Casualty Care recommendations.

RESULTS

A total of 114 trauma patients were treated during the time period. The mean age was 26.9 ± 10.1 years, 90% were males, and 96% were host nation patients. The most common mechanisms of injury were blast (49%) and gunshot (42%). Records were compliant with documenting a complete set of vitals in 58% and a pain score in 50% of patients. Recommendations for treatment of hypothermia were followed for 97% of patients. Tranexamic acid was given outside guidelines for 6% of patients, and for 40%, it was not determined if the guidelines were followed. Recommendations for initial resuscitative fluid were followed for 41% of patients. Recommendations for antibiotic prophylaxis were followed for 40% of intra-abdominal and 73% of soft tissue injuries. Recommendations for tetanus prophylaxis were followed for 90% of patients. Deep vein thrombosis prophylaxis was given to 32% of patients and contraindicated in 27%. The recommended transfusion ratio was followed for 56% of massive transfusion patients. Recommendations for calcium administration were followed for 40% of patients. When composite scores were created for individual surgeons, there was significant variability between surgeons with regard to adherence to guidelines.

CONCLUSIONS

There is significant deviation in the adherence to the CPGs.

LEVEL OF EVIDENCE

Epidemiologic study, level IV.

The impact of patient weight on burn resuscitation

BACKGROUND

Optimal fluid resuscitation of burn patients with burns greater than 20% total body surface area is critical to prevent burn shock during the initial 24 hours to 48 hours postburn. Currently, most resuscitation formulas incorporate the patient's weight when estimating 24-hour fluid requirements. The objective of this study was to determine the impact of weight on fluid resuscitation requirements and outcomes during the initial 24 hours after admission.

METHODS

We performed a retrospective review of patients admitted to our burn intensive care unit from December 2007 to April 2013, resuscitated with a computerized decision support system. We classified patients into body mass index (BMI) categories of underweight (BMI: <18.5), normal (BMI: 18.5-24.9), overweight (BMI: 25.0-29.9), or obese (BMI: >30.0). We also calculated the percent difference from ideal body weight (IBW) and compared 24-hour fluid volumes received.

RESULTS

Patients with missing weight and/or height values were excluded from the study, resulting in a final cohort of 161 patients for analysis. Mean total body surface area was 42 ± 20% with a full thickness burn of 18 ± 23%. Mean age, weight, and height were 47 ± 19 years, 83 ± 19 kg, and 68 ± 4 inches, respectively. IBW for this cohort was 68 ± 11 kg with a BMI of 28 ± 6. Univariate analysis showed significant differences in 24-hour resuscitation volumes (mL/kg) between normal and obese patients (p < 0.05). Further analysis revealed that increasing percent difference from IBW was associated with lower fluid volumes. Although obesity was not associated with inhalation injury or renal replacement therapy, it was correlated to an increased risk for mortality (p < 0.05).

CONCLUSION

This analysis showed that increasing weight was associated with lower fluid resuscitation volume requirements and a higher mortality rate, despite the low incidence of inhalation injury and renal replacement therapy in our obese patients. The use of actual body weight to drive resuscitation volumes may result in overresuscitation of obese patients, depending on the resuscitation formula. Further studies are needed to better explain the relationship between mortality and obesity in burn patients.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Non-traumatic Pulmonary Emergencies in the Deployed Setting

PURPOSE OF REVIEW

Pulmonary disorders accounted for up to 8% of the over 70,000 medical evacuations conducted from Iraq and Afghanistan in the past 15 years. This review of non-traumatic pulmonary emergencies provides an overview of deployed military medical treatment capabilities and highlights pulmonary emergencies requiring aeromedical evacuation from theater.

RECENT FINDINGS

Recent studies have improved the epidemiologic evaluation of non-traumatic pulmonary disease, highlighted specific parenchymal diseases, and revealed infection pathologies unique to the deployed setting. Literature regarding possible chemical exposures in the current deployed environment remains limited.

SUMMARY

Respiratory disorders requiring medical evacuation represent a wide variety of diseases. Complications such as pulmonary emboli, infectious pathogens, and hazardous chemical exposures threaten the deployed warfighter. Adequate medical care requires an understanding of these potential environmental exposures. This review serves as a general overview of this topic; however, more research regarding epidemiologic and environmental exposures is required.

Predicting the proportion of full-thickness involvement for any given burn size based on burn resuscitation volumes

INTRODUCTION

The depth of burn has been an important factor often overlooked when estimating the total resuscitation fluid needed for early burn care. The goal of this study was to determine the degree to which full-thickness (FT) involvement affected overall 24-hour burn resuscitation volumes.

METHODS

We performed a retrospective review of patients admitted to our burn intensive care unit from December 2007 to April 2013, with significant burns that required resuscitation using our computerized decision support system for burn fluid resuscitation. We defined the degree of FT involvement as FT Index (FTI; percentage of FT injury/percentage of total body surface area (TBSA) burned [%FT / %TBSA]) and compared variables on actual 24-hour fluid resuscitation volumes overall as well as for any given burn size.

RESULTS

A total of 203 patients admitted to our burn center during the study period were included in the analysis. Mean age and weight were 47 ± 19 years and 87 ± 18 kg, respectively. Mean %TBSA was 41 ± 20 with a mean %FT of 18 ± 24. As %TBSA, %FT, and FTI increased, so did actual 24-hour fluid resuscitation volumes (mL/kg). However, increase in FTI did not result in increased volume indexed to burn size (mL/kg per %TBSA). This was true even when patients with inhalation injury were excluded. Further investigation revealed that as %TBSA increased, %FT increased nonlinearly (quadratic polynomial) (R = 0.994).

CONCLUSION

Total burn size and FT burn size were both highly correlated with increased 24-hour fluid resuscitation volumes. However, FTI did not correlate with a corresponding increase in resuscitation volumes for any given burn size, even when patients with inhalation injury were excluded. Thus, there are insufficient data to presume that those who receive more volume at any given burn size are likely to be mostly full thickness or vice versa. This was influenced by a relatively low sample size at each 10%TBSA increment and larger burn sizes disproportionately having more FT burns. A more robust sample size may elucidate this relationship better.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Update on Severe Burn Management for the Intensivist

Thermal injury of humans causes arguably the most severe perturbations in physiology that can be experienced. These physiologic derangements start immediately and can persist in some form until months or even years after the burn wounds are healed. Burn shock, marked activation of the systemic inflammatory response, multiple-organ failure, infection, and wound failure are just a few of the insults that may require management by the intensivist. The purpose of this article is to review recent advances in the critical care management of thermally injured patients.

Prospective study examining clinical outcomes associated with a negative pressure wound therapy system and Barker's vacuum packing technique

BACKGROUND

The open abdomen has become a common procedure in the management of complex abdominal problems and has improved patient survival. The method of temporary abdominal closure (TAC) may play a role in patient outcome.

METHODS

A prospective, observational, open-label study was performed to evaluate two TAC techniques in surgical and trauma patients requiring open abdomen management: Barker's vacuum-packing technique (BVPT) and the ABThera(TM) open abdomen negative pressure therapy system (NPWT). Study endpoints were days to and rate of 30-day primary fascial closure (PFC) and 30-day all-cause mortality.

RESULTS

Altogether, 280 patients were enrolled from 20 study sites. Among them, 168 patients underwent at least 48 hours of consistent TAC therapy (111 NPWT, 57 BVPT). The two study groups were well matched demographically. Median days to PFC were 9 days for NPWT versus 12 days for BVPT (p = 0.12). The 30-day PFC rate was 69 % for NPWT and 51 % for BVPT (p = 0.03). The 30-day all-cause mortality was 14 % for NPWT and 30 % for BVPT (p = 0.01). Multivariate logistic regression analysis identified that patients treated with NPWT were significantly more likely to survive than the BVPT patients [odds ratio 3.17 (95 % confidence interval 1.22-8.26); p = 0.02] after controlling for age, severity of illness, and cumulative fluid administration.

CONCLUSIONS

Active NPWT is associated with significantly higher 30-day PFC rates and lower 30-day all-cause mortality among patients who require an open abdomen for at least 48 h during treatment for critical illness.

Early fluid resuscitation with hydroxyethyl starch 130/0.4 (6%) in severe burn injury: a randomized, controlled, double-blind clinical trial

Introduction

There are limited data on the efficacy of early fluid resuscitation with third-generation hydroxyethyl starch (HES 130) in burn injury. Adverse effects of HES on survival and organ function have been reported.

Methods

In this randomized, controlled, double-blind trial, 48 patients with severe burn injury were assigned to receive either lactated Ringer’s solution plus 6% HES 130/0.4 in a ratio of 2:1 or lactated Ringer’s solution with no colloid supplement for the first 72 hours. Primary outcome parameter was the group difference of administered total fluid from intensive care unit (ICU) admission up to day 3. Secondary outcomes included kidney and lung injury and failure, length of stay, and mortality.

Results

Three-day totals of administered resuscitation fluid (medians) were 21,190 mL in the lactated Ringer’s group and 19,535 mL in the HES group (HES: −1,213 mL; P = 0.39). Creatinine levels from day 1 to 3 (HES: +0.4 μmol/L; 95% confidence interval (CI) −18.7 to 19.5; P = 0.97) and urinary outputs from day 1 to 3 (HES: −58 mL; 95% CI −400 to 283; P = 0.90) were not different. Six patients in each group developed acute respiratory distress syndrome (ARDS) (risk ratio 0.96; 95% CI 0.35 to 2.64; P = 0.95). Length of ICU stay (HES vs. lactated Ringer’s: 28 vs. 24 days; P = 0.80) and length of hospital stay (31 vs. 29 days; P = 0.57) were similar. Twenty-eight-day mortality was 4 patients in each group (risk ratio 0.96; 95% CI 0.27 to 4.45; P = 0.95), and in-hospital mortality was 8 in the HES group vs. 5 patients in the lactated Ringer’s group (hazard ratio 1.86; 95% CI 0.56 to 6.19; P = 0.31).

Conclusions

There was no evidence that early fluid resuscitation with balanced HES 130/0.4 (6%) in addition to lactated Ringer’s solution would lead to a volume-sparing effect in severe burn injury. Together with the findings that early renal function, incidence of ARDS, length of stay, and mortality were not negatively influenced by HES in this setting, balanced HES 130/0.4 (6%) plus lactated Ringer’s solution could not be considered superior to lactated Ringer’s solution alone.

Trial registration

ClinicalTrials.gov NCT01012648

Implementation of a nurse-driven burn resuscitation protocol: a quality improvement project

BACKGROUND

Burn resuscitation, including titration of fluids and administration of colloids, is often driven by physicians' orders. Inconsistencies in burn resuscitation cause overresuscitation, which has adverse consequences.

METHODS

Retrospective chart reviews were completed to evaluate fluid resuscitation and complications for 12 months before and after development and implementation of a nurse-driven burn resuscitation protocol.

RESULTS

Before implementation of the protocol, results at 24 hours after injury indicated that 58% of patients were overresuscitated, had a serum level of lactate of at least 2 mmol/L (100%), and had complications (pulmonary edema 20%, abdominal compartment syndrome 7%, acute lung injury/acute respiratory distress syndrome 30%) within the first 5 days. Two outcomes differed from before to after implementation of the protocol: serum level of lactate at 24 hours (t(37.8) =2.38, P =.007) and central venous pressure at 48 hours (t(31) =2.27, P =.03). After implementation of the protocol, no patients had abdominal compartment syndrome develop.

CONCLUSIONS

Implementation of the nurse-driven burn resuscitation protocol improved nurses' awareness and assessment of fluid status during resuscitation and improved patients' outcomes.

Evaluation of military trauma system practices related to damage-control resuscitation

BACKGROUND

The Joint Theater Trauma System (JTTS) was developed with the vision that every soldier, marine, sailor, and airman injured on the battlefield would have the optimal chance for survival and maximum potential for functional recovery. In this analysis, we hypothesized that information diffusion through the JTTS, via the dissemination of clinical practice guidelines and process improvements, would be associated with the acceptance of evidence-based practices and decreases in trauma practice variability.

METHODS

The current evaluation was designed as a single time-series quasi-experimental study as a preanalysis and postanalysis relative to the implementation of clinical practice guidelines and process improvement interventions. Data captured from patients admitted to hospital-level (Level III) military treatment facilities in Iraq and Afghanistan from 2003 to 2010 were retrospectively analyzed from the Joint Theater Trauma Registry (JTTR) to determine the potential impact of process improvement initiatives on clinical practice.

RESULTS

The JTTS clinical practice guidelines for massive transfusion led to increased compliance with balanced component transfusion and decreased practice variability. During the course of the evaluation period, hypothermia on presentation decreased dramatically after the publication of the hypothermia prevention and management clinical practice guideline.

CONCLUSION

Developed metrics demonstrate that evidence-based quality improvement initiatives disseminated through the JTTS were associated with improved clinical practice of resuscitation following battlefield injury.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Prehospital burn management in a combat zone

OBJECTIVE

The purpose of this article is to provide a descriptive study of the management of burns in the prehospital setting of a combat zone.

METHODS

A retrospective chart review was performed of U.S. casualties with >20% total-body-surface-area thermal burns, transported from the site of injury to Ibn Sina Combat Support Hospital (CSH) between January 1, 2006, and August 30, 2009.

RESULTS

Ibn Sina CSH received 225 burn casualties between January 2006 and August 2009. Of these, 48 met the inclusion criteria. The mean Injury Severity Score was 31.7 (range 4 to 75). Prehospital vascular access was obtained in 24 casualties (50%), and 20 of the casualties received fluid resuscitation. Out of the 48 casualties enrolled, 28 (58.3%) did not receive prehospital fluid resuscitation. Of the casualties who received fluid resuscitation, nearly all received volumes in excess of the guidelines established by the American Burn Association and those recommended by the Committee for Tactical Combat Casualty Care. With regard to pain management in the prehospital setting, 13 casualties (27.1%) received pain medication.

CONCLUSIONS

With regard to the prehospital fluid resuscitation of primary thermal injury in the combat zone, two extremes were noted. The first group did not receive any fluid resuscitation; the second group was resuscitated with fluid volumes higher than those expected if established guidelines were utilized. Pain management was not uniformly provided to major burn casualties, even in several with vascular access. These observations support improved education of prehospital personnel serving in a combat zone.

A primer on burn resuscitation

Since the early 1900s, the scope of burn resuscitation has evolved dramatically. Due to various advances in pre-hospital care and training, under-resuscitation of patients with severe burns is now relatively uncommon. Over-resuscitation, otherwise known as “fluid creep”, has emerged as one of the most important problems during the initial phases of burn care over the past decade. To avoid the complications of over-resuscitation, careful hourly titration of fluid rates based on compilation of various clinical end points by a bedside provider is vital. The aim of this review is to provide a practical approach to the resuscitation of severely burned patients.

Management of war-related burn injuries: lessons learned from recent ongoing conflicts providing exceptional care in unusual places

Thermal injury is a sad but common and obligatory component of armed conflicts. Although the frequency of noncombat burns has decreased, overall incidence of burns in current military operations has nearly doubled during the past few years. Burn injuries in the military environment do not need to be hostile in nature. Burns resulting from carelessness outnumber those resulting from hostile action. Unfortunately, civilians are becoming the major targets in modern-day conflicts; they account for more than 80% of those killed and wounded in present-day conflicts. The provision of military burn care mirrors the civilian standards; however, several aspects of treatment of war-related burn injuries are peculiar to the war situation itself and to the specific conditions of each armed conflict. Important aspects of management of burned military personnel include triage to ensure that available medical care resources are matched to the severity of burn injury and the number of burn casualties, initial management and resuscitation in the combat zone, and subsequent evacuation to higher echelons of medical care, each with increasing medical capabilities. Care of military victims is usually well structured and follows strict guidelines for first aid and evacuation to field hospitals by military personnel usually having had some form of training in first aid and resuscitation and for which necessary equipment and material for such interventions are more or less available. Options available for civilian injury intervention in wartime, however, are limited. Of all pre-hospital transport of civilian victims, 70% are done by lay public and 93% receive in the field, or during transport, some form of basic first aid administered by relatives, friends, or other first responders not trained for such interventions. Civilian casualties frequently represents 60% to 80% of all injured admitted to the level III facilities of overseas forces stationed throughout the host country. Unlike military personnel who are rapidly evacuated to higher echelons IV and V for definitive and long-term care, civilians must receive definitive burn treatment at these level III military facilities. The present review was intended to highlight peculiar aspects of war-related burn injuries of both military personnel and civilians and their management based on the most recently published material that, for the most part, is related to the recent conflicts in Iraq and Afghanistan.

Early fluid resuscitation with hyperoncotic hydroxyethyl starch 200/0.5 (10%) in severe burn injury

Introduction

Despite large experience in the management of severe burn injury, there are still controversies regarding the best type of fluid resuscitation, especially during the first 24 hours after the trauma. Therefore, our study addressed the question whether hyperoncotic hydroxyethyl starch (HES) 200/0.5 (10%) administered in combination with crystalloids within the first 24 hours after injury is as effective as 'crystalloids only' in severe burn injury patients.

Methods

30 consecutive patients were enrolled to this prospective interventional open label study and assigned either to a traditional 'crystalloids only' or to a 'HES 200/0.5 (10%)' volume resuscitation protocol. Total amount of fluid administration, complications such as pulmonary failure, abdominal compartment syndrome, sepsis, renal failure and overall mortality were assessed. Cox proportional hazard regression analysis was performed for binary outcomes and adjustment for potential confounders was done in the multivariate regression models. For continuous outcome parameters multiple linear regression analysis was used.

Results

Group differences between patients receiving crystalloids only or HES 200/0.5 (10%) were not statistically significant. However, a large effect towards increased overall mortality (adjusted hazard ratio 7.12; P = 0.16) in the HES 200/0.5 (10%) group as compared to the crystalloids only group (43.8% versus 14.3%) was present. Similarly, the incidence of renal failure was 25.0% in the HES 200/0.5 (10%) group versus 7.1% in the crystalloid only group (adjusted hazard ratio 6.16; P = 0.42).

Conclusions

This small study indicates that the application of hyperoncotic HES 200/0.5 (10%) within the first 24 hours after severe burn injury may be associated with fatal outcome and should therefore be used with caution.

Trial registration

NCT01120730.

Decompressive abdominal laparotomy for abdominal compartment syndrome in an unengrafted bone marrow recipient with septic shock

Objective. To describe a profoundly immunocompromised (panleukopenia) child with septic shock who developed abdominal compartment syndrome (ACS) and was successfully treated with surgical decompression. Design. Individual case report. Setting. Pediatric intensive care unit of a tertiary children's hospital. Patient. A 32-month-old male with Fanconi anemia who underwent bone marrow transplantation (BMT) 5 days prior to developing septic shock secondary to Streptococcus viridans and Escherichia coli ACS developed after massive fluid resuscitation, leading to cardiopulmonary instability. Interventions. Emergent surgical bedside laparotomy and silo placement. Measurements and Main Results. The patient's cardiopulmonary status stabilized after decompressive laparotomy. The abdomen was closed and the patient survived to hospital discharge without cardiac, respiratory, or renal dysfunction. Conclusions. The use of laparotomy and silo placement in an unengrafted BMT patient with ACS and septic shock did not result in additional complications. Surgical intervention for ACS is a reasonable option for high risk, profoundly immunocompromised patients.

Early acute kidney injury predicts progressive renal dysfunction and higher mortality in severely burned adults

The incidence and prognosis of acute kidney injury (AKI) developing during acute resuscitation have not been well characterized in burn patients. The recently developed Risk, Injury, Failure, Loss, and End-stage (RIFLE) classification provides a stringent stratification of AKI severity and can allow for the study of AKI after burn injury. We hypothesized that AKI frequently develops early during resuscitation and is associated with poor outcomes in severely burned patients. We conducted a retrospective review of patients enrolled in the prospective observational multicenter study "Inflammation and the Host Response to Injury." A RIFLE score was calculated for all patients at 24 hours and throughout hospitalization. Univariate and multivariate analyses were performed to distinguish the impact of early AKI on progressive renal dysfunction, need for renal replacement therapy, and hospital mortality. A total of 221 adult burn patients were included, with a mean TBSA burn of 42%. Crystalloid resuscitation averaged 5.2 ml/kg/%TBSA, with urine output of 1.0 +/- 0.6 ml/kg/hr at 24 hours. Sixty-two patients met criteria for AKI at 24 hours: 23 patients (10%) classified as risk, 32 patients (15%) as injury, and 7 (3%) as failure. After adjusting for age, TBSA, inhalation injury, and nonrenal Acute Physiology and Chronic Health Evaluation II > or =20, early AKI was associated with an adjusted odds ratio 2.9 for death (95% CI 1.1-7.5, P = .03). In this cohort of severely burned patients, 28% of patients developed AKI during acute resuscitation. AKI was not always transient, with 29% developing progressive renal deterioration by RIFLE criteria. Early AKI was associated with early multiple organ dysfunction and higher mortality risk. Better understanding of how early AKI develops and which patients are at risk for progressive renal dysfunction may lead to improved outcomes.

Use of tourniquets and their effects on limb function in the modern combat environment

Tourniquets have been called powerful lifesaving devices by some authors, whereas others say they cause more harm than good. Given recent emergency tourniquet developments in scientific design of devices, widespread user training, modern doctrine based on evidence, and thorough fielding to users within an integrated trauma system with rapid evacuation, tourniquets have shown minor morbidity and major lifesaving results. Trauma systems with poorly designed devices, inadequate user training, no tourniquet doctrine, or slow casualty evacuation, however, have repeatedly shown severe morbidity and mortality. Tourniquets may save lives if the right device is used in the right way at the right time for the right patient.

Compartment syndrome and lower-limb fasciotomies in the combat environment

Prophylactic and therapeutic treatment of leg compartment syndrome with decompression by double-incision fasciotomy prevents progression of soft-tissue injury in high-energy trauma. This treatment is the standard of care in civilian trauma and combat settings. More controversial is the use of either single- or dual-incision fasciotomy of the foot for prophylactic treatment of foot compartment syndrome. Fasciotomy must be performed in the face of major trauma to the foot with severe swelling and unremitting pain. The role for prophylactic fasciotomy of the foot is unclear and should be considered on a case by case basis. The surgeon must maintain a high degree of vigilance for the development of compartment syndrome in the combat casualty.

Impact of joint theater trauma system initiatives on battlefield injury outcomes

INTRODUCTION

The US military forces developed and implemented the Joint Theater Trauma System (JTTS) and Joint Theater Trauma Registry (JTTR) using US civilian trauma system models with the intent of improving outcomes after battlefield injury.

METHODS

The purpose of this analysis was to elaborate the impact of the JTTS. To quantify these achievements, the JTTR captured mechanism, acute physiology, diagnostic, therapeutic, and outcome data on 23,250 injured patients admitted to deployed US military treatment facilities from July 2003 through July 2008 for analysis. Comparative analysis to civilian trauma systems was done using the National Trauma Data Bank (NTDB).

RESULTS

In contrast to civilian trauma systems with an 11.1% rate of penetrating injury, 68.3% of battlefield wounds were by penetrating mechanism. In the analyzed cohort, 23.3% of all patients had an Injury Severe Score (ISS) > or = 16, which is similar to the civilian rate of 22.4%. In the military injury population, 66% of injuries were combat-related. In addition, in the military injury group, 21.8% had metabolic evidence of shock with a base deficit > or = 5, 29.8% of patients required blood transfusion, and 6.4% of the total population of combat casualties required massive transfusion (>10 U red blood cells/24 hours). With this complex and severely injured population of battlefield injuries, the JTTS elements were used to recognize and remedy more than 60 trauma system issues requiring leadership and advocacy, education, research, and alterations in clinical care. Of particular importance to the trauma system was the implementation and tracking of performance improvement indicators and the dissemination of 27 evidence-based clinical practice guidelines (CPGs). In particular, the damage control resuscitation guideline was associated with a decrease in mortality in the massively transfused from 32% pre-CPG to 21% post-CPG. As evidence of the effectiveness of the JTTS, a mortality rate of 5.2% after battlefield hospital admission is comparable to a case fatality rate of 4.3% reported in an age-matched cohort from the NTDB.

CONCLUSIONS

JTTS initiatives contributed to improved survival after battlefield injury. The JTTS has set the standard of trauma care for the modern battlefield using contemporary systems-based methodologies.

Nonoperative management of intraabdominal hypertension and abdominal compartment syndrome

Intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) have detrimental effects on all organ systems and are associated with significant morbidity and mortality. In recent years, the diagnosis and management of these syndromes has evolved tremendously, and the importance of comprehensive strategies to reduce intraabdominal pressure (IAP) has been recognized. All clinicians should be aware of the risk factors that predict the development of IAH/ACS, the appropriate measurement of IAP, and the current resuscitation options for managing these highly morbid syndromes. The nonoperative management of IAH/ACS can be summarized using five therapeutic goals: evacuate intraluminal contents, evacuate intraabdominal space-occupying lesions, improve abdominal wall compliance, optimize fluid administration, and optimize systemic and regional tissue perfusion. Surgical intervention through open abdominal decompression should immediately be pursued for patients with progressive IAH, end-organ dysfunction, and failure that is refractory to these nonoperative therapies. This comprehensive management strategy has been demonstrated to improve patient survival and long-term outcome.