Landstuhl Regional Medical Center Research Articles

164 Influence of Time to Transport to a Higher Level Facility on the Clinical Outcomes of US Combat Casualties With Traumatic Brain Injury: A Multicenter 7-Year Study

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and is associated with mortality rates as high as 30%. Patients with TBI are at high risk for secondary injury and need to be transported to definitive care expeditiously. However, the physiologic effects of aeromedical evacuation are not well understood and may compound these risks. It is unknown if combat TBI patients may benefit from early versus delayed aeromedical evacuation. The aim of this study was to evaluate the impact of transport timing out of theater via CCATT to a higher-level facility on the clinical outcomes of combat casualties with TBI. We performed a retrospective record review of patients with TBI who were evacuated out of theater by Critical Care Air Transport Teams (CCATT) from January 2007 to May 2014. Data abstractors collected flight information, laboratory values, vital signs, procedures, and clinical in-flight assessments. Outcomes were obtained from the Department of Defense Trauma Registry (DoDTR). Time to transport was defined as the time (in days) from injury to CCATT evacuation out of combat theater. We calculated descriptive statistics and constructed multivariable regression models to determine the association between time to transport and clinical outcomes. We examined the records of 438 patients transported via CCATT from a Role III facility to Landstuhl Regional Medical Center (LRMC). For analyses we categorized patients into three groups: those transported in one day or less (n=165, 38% of the sample), two days (n=163, 37%), and three days or more (n=110, 25%). Multivariable logistic regression models indicated that patients with longer time to transport (ie, two days, or three or more days) had 50% lower odds of being discharged on a ventilator and were twice as likely to return to duty or be discharged home, even after adjusting for demographics, injury severity, and injury type. Additionally, patients transported in three or more days were 70% less likely to be ventilated at discharge with a GCS of 8 or lower and had 28% lower odds of mortality when compared to those transported in one day or less. In patients with moderate to severe TBI, a delay in aeromedical evacuation out of the combat theater was associated with lower odds of mortality and ventilation at discharge and a higher likelihood of discharge to home and return to duty dispositions.

365 Incidence of Venous Thromboembolism in Critical Care Air Transport Team-Evacuated Casualties Transported to Landstuhl Regional Medical Center

Critically injured combat casualties are transported to Landstuhl Regional Medical Center (6-9 hour flights) via Critical Care Air Transport Teams (CCATTs). Immobility and prolonged air travel following traumatic injury may increase the risk of venous thromboembolism (VTE), yet studies on the incidence of VTE following traumatic injury and prolonged air transport are limited. Our objective was to determine factors associated with the incidence of VTE in patients evacuated from theater by CCATTs. We performed a retrospective record review of trauma patients evacuated from the combat setting by CCATT between March 2007 and December 2011. From CCATT records and Department of Defense Trauma Registry query we collected demographics, injury description, vital signs, labs, thromboprophylaxis, adverse events, and disposition up to 30 days. Data elements abstracted from theater medical records included VTE diagnostic information and relevant procedures with timestamps as available. Patients with at least one documented incidence of DVT or pulmonary embolism were grouped into VTE and compared to patients with no deep venous thrombosis or PE (No VTE). Continuous data were analyzed and reported as median (Interquartile Range), while categorical data were reported as frequencies and percentages. Regression models were performed to identify factors associated with the development of VTE. Of the 1351 CCATT records reviewed, 205 records had diagnoses of DVT (n=114), PE (n=69), or both (n=22). Thirty-five records had more than one occurrence of VTE documented. Subjects were male (98%) with median age of 24 (21-29) years. Comparing VTE versus No VTE there was no difference in age, sex, or injury severity. The VTE group was more likely to have sustained injuries related to a fall (5% versus 2%, p=0.015) or blast (75% versus 67%, p=0.027) compared to No VTE group. The VTE group was more likely to receive blood products pre-flight (p<0.001), during flight (p<0.001), and post-flight (p<0.001). The VTE and No VTE group received procoagulants, anticoagulants, and thromboprophylaxis pre-flight at similar rates. From regression models, a low pre-flight hemoglobin level (<8 g/dL), a pH of ≥7.4, and the administration of platelets were associated with VTE (p<0.001). Other pre-flight labs were similar between groups. There was no difference in proportion of patients who required ventilator support during transport (70% versus 65%, p=0.120), but after flight, the VTE group was more likely to be intubated (72% versus 65%, p=0.029). The VTE group compared to No VTE group was more likely to have an adverse event (such as aspiration pneumonia or cardiac arrest) post-flight (95% versus 90%, p=0.037). Mortality rates did not differ between groups (3.8% versus 4.1%, p=0.859). Of the survivors, the VTE group had more hospital days (p=0.047). The proportion of patients who continued to receive medical care (2.9% versus 2.8%) at 30 days post injury did not differ. The VTE group was more likely to receive blood products before, during, and after flight. Factors associated with VTE included a low hemoglobin level, pH of 7.4 or greater, and platelet administration in spite of the administration of anticoagulants. Further research is needed to determine whether this is related to low red cell to platelet ratios, continued bleeding, or other dysfunctional physiologic response in the coagulation system.

Descriptive Analysis of Cardiac Patients Transported by Critical Care Air Transport Teams.

Critical Care Air Transport Teams (CCATTs) transport critically ill patients within and out of theaters of combat operations. Studies of the CCATT population reveal as many as 35% of patients have a non-trauma diagnosis, of which more than half are cardiac.The purpose of this retrospective study was to describe the epidemiology of critically ill patients with cardiac diagnoses evacuated from theater via CCATT. We conducted a retrospective review of 290 medical patients with a primary cardiac diagnosis transported from any theater of operation to Landstuhl Regional Medical Center, Germany from January 2007 to April 2015. The majority of patients were male with an average age of 46 ± 11 years, US contractors (47%, n = 137), followed by US Active Duty (32%, n = 93). Patients had an average BMI of 29 ± 5; 62% of cardiac patients were either overweight or obese. The most common cardiac diagnoses were ST elevation myocardial infarction, Non-ST elevation myocardial infarction, and angina. Pre-flight vital signs indicate overall patients were stable prior to evacuation, with the majority receiving supplemental oxygen and only 5% requiring mechanical ventilation. Eighty-one percent of patients experienced at least one cardiac event during flight, however less than 5% required adjustment to oxygen or ventilator settings. Critically ill cardiac patients make up a significant portion of patients transported out of the combat theater. These patients are older, overweight and have identified risk factors for cardiac morbidity. More strenuous pre-deployment screening for risk factors and prevention strategies could minimize the use of military resources to evacuate these patients from the combat theater.

Treatment of Suspected Invasive Fungal Infection in War Wounds.

Invasive fungal wound infections (IFIs) were an unexpected complication associated with blast-related wounds during Operation Enduring Freedom. Between 2010 and 2012, IFI incidence rates were as high as 10-12% for patients injured during Operation Enduring Freedom and admitted to the intensive care unit at the Landstuhl Regional Medical Center. Independent risk factors for the development of IFIs include dismounted blast injuries, above knee amputations and massive (>20 units) packed red blood cell transfusions within 24 hours after injury. The Joint Trauma System developed a Clinical Practice Guideline on IFI prevention, identification and management. Aggressive and frequent surgical debridement remains the primary therapy accompanied by topical antifungal therapy (e.g., Dakins solution). Empiric systemic antifungal therapy with both liposomal amphotericin B and an intravenous broad-spectrum triazole (e.g., voriconazole or posaconazole) should be administered when there is strong suspicion of IFI based on the occurrence of recurrent wound necrosis following serial surgical debridements, since many cases involve multiple fungal species. Other recommendations include: (1) early tissue sampling for wound histopathology and fungal cultures, (2) early consultation with infectious disease specialists, and (3) coordination with surgical pathology and clinical microbiology.

Relapsing Polychondritis Manifesting as Tracheal and Costochondral Inflammation on Magnetic Resonance Imaging

From the ∗Rheumatology Service, Division of Medicine †Pulmonary and Critical Care Service, Division of Medicine ‡Department of Radiology, Landstuhl Regional Medical Center, Landstuhl, Germany. The authors declare no conflict of interest. The view(s) expressed herein are those of the author(s) and do not reflect the official policy or position of Landstuhl Regional Medical Center, the US Army Medical Department, the US Army Office of the Surgeon General, the Department of the Army or the Department of Defense, or the US Government. The authors are employees of the US government. This work was prepared as part of their official duties and, as such, there is no copyright to be transferred. Correspondence: Ian M. Ward, MD, Rheumatology Service, Landstuhl Regional Medical Center, CMR 402, Box 2107, APO, AE 09180-0022, Landstuhl, Germany. E-mail: [email protected].

A Legacy of Lessons Learned: Landstuhl Regional Medical Center During Wartime, 2001–2014

A Legacy of Lessons Learned by Karen Hennessy is a mix of history and organizational practice focused on the Landstuhl Regional Medical Center (LRMC), the largest US military medical facility in Europe. Before September 11, 2001, LRMC was a general care hospital for US military personnel and their families stationed in Europe. As troops were distributed to parts of the Middle East, Europe, and Africa in conflicts following September 11, 2001, LRMC developed into a premier trauma center caring for service members wounded in US military conflicts and then evacuated to LRMC. LRMC became a transition point for wounded and critically ill soldiers evacuated from their deployment, with approximately 20 percent of patients being returned to duty while many injured patients were transported on to facilities in the United States within 96 hours of arrival at LRMC.

Clinical Impact of Cabin Altitude Restriction Following Aeromedical Evacuation.

Combat medical care relies on aeromedical evacuation (AE). Vital to AE is the validating flight surgeon (VFS) who warrants a patient is "fit to fly." To do this, the VFS considers clinical characteristics and inflight physiological stressors, often prescribing specific interventions such as a cabin altitude restriction (CAR). Unfortunately, limited information is available regarding the clinical consequences of a CAR. Consequently, a dual case-control study (CAR patients versus non-CAR patients and non-CAR patients flown with a CAR versus non-CAR patients) was executed. Data on 1,114 patients were obtained from TRANSCOM Regulating and Command and Control Evacuation System and Landstuhl Regional Medical Center trauma database (January 2007 to February 2008). Demographic and clinical factors essentially showed no difference between groups; however, CAR patients appeared more severely injured than non-CAR patients. Despite being sicker, CAR patients had similar clinical outcomes when compared with non-CAR patients. In contrast, despite an equivocal severity picture, the non-CAR patients flown with a CAR had superior clinical outcomes when compared with non-CAR patients. It appeared that the CAR prescription normalized severely injured to moderately injured and brought moderately injured into a less morbid state. These results suggest that CAR should be seriously considered when evacuating seriously ill/injured patients.

Does Subcutaneous Infiltration of Liposomal Bupivacaine Following Single-Level Transforaminal Lumbar Interbody Fusion Surgery Improve Immediate Postoperative Pain Control?

Study DesignRetrospective case-control study using prospectively collected data.PurposeEvaluate the impact of liposomal bupivacaine (LB) on postoperative pain management and narcotic use following standardized single-level low lumbar transforaminal lumbar interbody fusion (TLIF).Overview of LiteraturePoor pain control after surgery has been linked with decreased pain satisfaction and increased economic burden. Unfortunately, opioids have many limitations and side effects despite being the primary treatment of postoperative pain. LB may be a form of pre-emptive analgesia used to reduce the use of postoperative narcotics as evidence in other studies evaluating its use in single-level microdiskectomies.MethodsThe infiltration of LB subcutaneously during wound closure was performed by a single surgeon beginning in July 2014 for all single-level lumbar TLIF spinal surgeries at Landstuhl Regional Medical Center. This cohort was compared against a control cohort of patients who underwent the same surgery by the same surgeon in the preceding 6 months. Statistical analysis was performed on relevant variables including: morphine equivalents of narcotic medication used (primary outcome), length of hospitalization, Visual Analog Scale pain scores, and total time spent on a patient-controlled analgesia (PCA) pump.ResultsA total of 30 patients were included in this study; 16 were in the intervention cohort and 14 were in the control cohort. The morphine equivalents of intravenous narcotic use postoperatively were significantly less in the LB cohort from day of surgery to postoperative day 3. Although the differences lost their statistical significance, the trend remained for total (oral and intravenous) narcotic consumption to be lower in the LB group. The patients who received the study intervention required an acute pain service consult less frequently (62.5% in LB cohort vs. 78.6% in control cohort). The amount of time spent on a PCA pump in the LB group was 31 hours versus 47 hours in the control group (p=0.1506).ConclusionsLocal infiltration of LB postoperatively to the subcutaneous tissues during closure following TLIF significantly decreased the amount of intravenous narcotic medication required by patients. Well-powered prospective studies are still needed to determine optimal dosing and confirm benefits of LB on total narcotic consumption and other measures of pain control following major spinal surgery.

Impact of Critical Care Air Transport Team (CCATT) ventilator management on combat mortality.

Aeromedical evacuation platforms such as Critical Care Air Transport Teams (CCATTs) play a vital role in the transport and care of critically injured and ill patients in the combat theater. Mechanical ventilation is used to support patients with failing respiratory function and patients requiring high levels of sedation. Mechanical ventilation, if not managed appropriately, can worsen or cause lung injury and contribute to increased morbidity. The purpose of this study was to evaluate the impact of ARDSNet protocol compliance during aeromedical evacuation of ventilated combat injured patients. We performed a retrospective chart review of combat injured patients transported by CCATTs from Afghanistan to Landstuhl Regional Medical Center (LRMC) in Germany between January 2007 and January 2012. After univariate analyses, we performed regression analyses to assess compliance and post-flight outcomes. Cox proportional hazard models were used to evaluate associations between the risk factor of non-compliance with increased number of ventilator, ICU, or hospital days. Nominal logistic regression models were performed to evaluate the association between non-compliance and mortality. Sixty-two percent (n = 669) of 1,086 patients required mechanical ventilation during transport. A total of 650 patients required volume-controlled mechanical ventilation and were included in the analysis. Of the 650 subjects, 62% (n = 400) were non-compliant per tidal volume and ARDSNet table recommendations. The groups were similar in all demographic variables, except the Non-compliant group had a higher Injury Severity Score compared to the Compliant group. Subjects in the Compliant group were less likely to have an incidence of acute respiratory distress, acute respiratory failure, and ventilator-associated pneumonia when combing the variables (2% vs. 7%, p < 0.0069). The Non-compliant group had an increased incidence of in-flight respiratory events, required more days on the ventilator and in the ICU, and had a higher mortality rate. Compliance with the ARDSNet guidelines was associated with a decrease in ventilator days, ICU days, and 30-day mortality. Therapeutic/care management, level IV.

Critical Care Air Transport Team Evacuation of Medical Patients Without Traumatic Injury.

Air Force Critical Care Air Transport Teams (CCATTs) provide fixed-wing aeromedical evacuation for combat casualties. Multiple studies have evaluated CCATT trauma patients; however, nearly 50% of patients medically evacuated from combat theaters are for nontraumatic medical illnesses to include stroke, myocardial infarctions, overdose, and pulmonary emboli. Published data are limited regarding illness types, in-flight procedures, and adverse events. The objective of our study was to characterize patients with nontraumatic medical illnesses transferred via CCATT to include a description of in-flight procedures and events. We performed a retrospective review of CCATT medical records of patients with nontraumatic medical illnesses transported via CCATT from theater of operations to Landstuhl Regional Medical Center between January 2007 and April 2015. We abstracted data from CCATT records to include demographics, description of current illness, vital signs, labs, in-flight procedures and medications, and in-flight adverse events. Following descriptive analysis, comparative tests were performed based on service status of patients and primary diagnoses. We reviewed 672 records of critically ill medical patients transported via CCATT, most of whom were male (90%, n = 606). Approximately 56% of the patients were U.S. active duty members; the remainder included U.S. contractors and civilians, and foreign citizens or unknown. The three categories (active duty, contractor/civilian, foreign/unknown) significantly differed from one another in age. Over half of the patients received a primary or secondary cardiac diagnosis. The most common in-flight procedures and medications included supplementary oxygenation, anticoagulant/antiplatelet medications, analgesics, and ventilation. Up to 20% of patients required continuous medication infusions other than analgesics. Patients most frequently experienced in-flight complications related to their primary diagnoses. Fifty-six percent (672) of 1,209 CCATT records that were queried were of patients with medical conditions. The most common primary diagnoses of CCATT medical patients were cardiac, pulmonary, and neurological in etiology. Mechanical ventilation and continuous medication infusions were required in approximately 20% of patients. The data provided by this study may assist in guiding future CCATT training requirements and resource allocation, as well as clinical practice guideline development.

Multispecialty Synchronous Telehealth Utilization and Patient Satisfaction Within Regional Health Command Europe: A Readiness and Recapture System for Health.

Telehealth implementation within the Military Healthcare System continues to advance toward the goal of a mature regional health platform; however, specialty-specific usage or patient satisfaction regarding synchronous or "real-time" telehealth at the regional military hospital level has not been described. A retrospective review of synchronous telehealth encounters and patient satisfaction surveys from Landstuhl Regional Medical Center (LRMC) specialty clinics engaging in synchronous telehealth to regional Army Health Clinics (AHCs) during 2015 was conducted. 2,354 synchronous telehealth encounters were conducted for 1,886 unique patients. The majority of patients were adults (88.4%), male (71.1%), and active duty (75%). Twelve distinct distant locations were engaged in synchronous telehealth with 31 distinct specialties. 1,552 (62.5%) patients had a single telehealth visit with a median (range) of 1 (1-7) visit. Median (range) visits per specialty was 25 (1-582) with sleep medicine (24.7%), general surgery (13.1%), nutrition (9.7%), orthopedics (9.0%), and ENT (6.0%) representing 62.5% of all encounters. Median (range) number of encounters per location was 146 (13-685). Surgical specialties preferentially evaluated patients at locations with a specialty-trained presenter (p < 0.001), whereas nonsurgical specialties did not (p > 0.05). Fifteen percent (372/2,354) of patients completed an anonymous survey at the time of their telehealth visit. Mean responses on a 5-point Likert scale ranging from "strongly disagree" (1) to "strongly agree" (5) was 4.8 ± 0.5 for both recommending and being satisfied with their telehealth visit. The 2,354 telehealth visits represented 2.4% (2,354/100,094) of all visits to LRMC during 2015 for 25 of 31 specialties whose total outpatient visits could be determined. Clinic utilization varied between specialties as well as whether a specialty-trained patient presenter was preferred. This robust multispecialty synchronous telehealth experience provides insight into both specialty-specific utilization and patient satisfaction which may aid regional medical centers recognizing avenues for specialty-specific telehealth initiatives.

Impact of Operational Theater on Combat and Noncombat Trauma-Related Infections.

The Trauma Infectious Disease Outcomes Study began in June 2009 as combat operations were decreasing in Iraq and increasing in Afghanistan. Our analysis examines the rate of infections of wounded U.S. military personnel from operational theaters in Iraq and Afghanistan admitted to Landstuhl Regional Medical Center between June 2009 and December 2013 and transferred to a participating U.S. hospital. Infection risk factors were examined in a multivariate logistic regression analysis (expressed as odds ratios [OR]; 95% confidence intervals [CI]). The study population includes 524 wounded military personnel from Iraq and 4,766 from Afghanistan. The proportion of patients with at least one infection was 28% and 34% from the Iraq and Afghanistan theaters, respectively. The incidence density rate was 2.0 (per 100 person-days) for Iraq and 2.7 infections for Afghanistan. Independent risk factors included large-volume blood product transfusions (OR: 10.68; CI: 6.73-16.95), high Injury Severity Score (OR: 2.48; CI: 1.81-3.41), and improvised explosive device injury mechanism (OR: 1.84; CI: 1.35-2.49). Operational theater (OR: 1.32; CI: 0.87-1.99) was not a risk factor. The difference in infection rates between operational theaters is primarily a result of increased injury severity in Afghanistan from a higher proportion of blast-related trauma during the study period.

Early traumatic brain injury screen in 6594 inpatient combat casualties

IntroductionThe purpose of this study was to review the inpatient traumatic brain injury (TBI) screening program at a Role IV regional resource trauma center. TBI has been coined the “signature wound” during current U.S. combat operations. All patients injured in Iraq or Afghanistan who transit through Landstuhl Regional Medical Center (LRMC) undergo an initial TBI screen regardless of anatomic injury. The incidence and factors associated with positive screening for concussion (physical event+alteration of consciousness (AOC)) and TBI diagnoses were examined. MethodsA retrospective review of consecutively admitted patients to LRMC who underwent a TBI screen from 5/06 to 7/11 was performed. Patient characteristics, self-reported symptoms, and TBI diagnoses were analyzed. FindingsAmong 43,852 patients screened during the 5-year period, 6594 were admitted, of whom, 6590 received a complete TBI screen. Predominantly male (97.1%), the mean age was 26.7±7.4 yrs. The average GCS and ISS at admission were 13.9±2.8 and 10.1±8.6, respectively. Positively screened patients averaged 1.8 deployments, 69.5% experienced one or more blasts, 16.1% experienced one or more vehicular crashes, with 18.0% reporting a prior head injury. Of the 2805 (42.6%) who screened positive for possible concussion, 2393 (85.3%) were diagnosed with a concussion/TBI during their inpatient stay; the remaining 412 (14.7%) were identified by screening only. Of the screened positive patients, 1953 (69.6%) reported 1 or more current concussion/TBI-related symptoms; of those with symptom(s), 532 (27.2%) reported 5 or more. ConclusionsEarly screening based on self-report identified a large number of patients admitted directly from the combat zone with possible deployment-related concussion and TBI symptoms. Such screening provides valuable information to guide decisions about early management and return to duty. Level of evidenceLevel III, Therapeutic.

Clinical assessment and management of general surgery patients via synchronous telehealth

Objective This paper describes how a clinical team at Landstuhl Regional Medical Center (LRMC) successfully integrated synchronous telehealth (TH) into their routine clinical practice. Methods and materials Synchronous TH encounters were performed using Polycom® software on surgeons’ computers with high-definition (HD) cameras on monitors at distant sites and PolyCom HDX9000® Telehealth Practitioner Carts at originating sites. Patients provided consented and were presented to general surgeons by nurses and medical technicians at Army health clinics throughout the European Theater. Results In calendar year (CY) 2014, five general surgeons and two surgical physician assistants (PAs) at Landstuhl Regional Medical Center along with registered nurses (RNs) at six originating clinic sites throughout Europe completed 130 synchronous TH encounters for 101 general surgery patients resulting in 73 completed and 16 recommended surgeries. Eighty-eight percent of patients had a completed or recommended surgery. No surgeries or procedures planned after initial TH evaluation were cancelled. Originating site clinics ranged in distance from 68 miles to 517 miles. Acceptance by providers, patients and clinic staff was high. Conclusion Synchronous TH was effective and safe in evaluating common general surgical conditions. We excluded sensitive and complex conditions requiring a nuanced physical examination. The TH efforts of the general surgery staff have resulted in high-quality, seamless and predictable TH activities that continue to expand into other surgical and medical specialties beyond general surgery. Seven surgeons and two PAs use synchronous TH regularly serving patients over a broad geographic area.

Outcome Trends after US Military Concussive Traumatic Brain Injury.

Care for US military personnel with combat-related concussive traumatic brain injury (TBI) has substantially changed in recent years, yet trends in clinical outcomes remain largely unknown. Our prospective longitudinal studies of US military personnel with concussive TBI from 2008-2013 at Landstuhl Regional Medical Center in Germany and twp sites in Afghanistan provided an opportunity to assess for changes in outcomes over time and analyze correlates of overall disability. We enrolled 321 active-duty US military personnel who sustained concussive TBI in theater and 254 military controls. We prospectively assessed clinical outcomes 6-12 months later in 199 with concussive TBI and 148 controls. Global disability, neurobehavioral impairment, depression severity, and post-traumatic stress disorder (PTSD) severity were worse in concussive TBI groups in comparison with controls in all cohorts. Global disability primarily reflected a combination of work-related and nonwork-related disability. There was a modest but statistically significant trend toward less PTSD in later cohorts. Specifically, there was a decrease of 5.9 points of 136 possible on the Clinician Administered PTSD Scale (-4.3%) per year (95% confidence interval, 2.8-9.0 points, p = 0.0037 linear regression, p = 0.03 including covariates in generalized linear model). No other significant trends in outcomes were found. Global disability was more common in those with TBI, those evacuated from theater, and those with more severe depression and PTSD. Disability was not significantly related to neuropsychological performance, age, education, self-reported sleep deprivation, injury mechanism, or date of enrollment. Thus, across multiple cohorts of US military personnel with combat-related concussion, 6-12 month outcomes have improved only modestly and are often poor. Future focus on early depression and PTSD after concussive TBI appears warranted. Adverse outcomes are incompletely explained, however, and additional studies with prospective collection of data on acute injury severity and polytrauma, as well as reduced attrition before follow-up will be required to fully address the root causes of persistent disability after wartime injury.

Acute Kidney Injury in Critically Injured Combat Veterans: A Retrospective Cohort Study

Acute kidney injury (AKI) has been associated with mortality after traumatic injury. However, there is a paucity of data for military service members with injuries received in combat. We sought to identify risk factors for AKI after combat trauma and evaluate whether AKI is a predictor of mortality. Retrospective observational study. US service members who were critically wounded in Iraq or Afghanistan from February 1, 2002, to February 1, 2011, and survived until evacuation to Landstuhl Regional Medical Center, Germany. Demographic variables, vital signs, injury severity score, presence of burn injury, and mechanism of injury as defined at the time of initial injury, as well as the presence of AKI ascertained within the first 7 days using KDIGO (Kidney Disease: Improving Global Outcomes) serum creatinine criteria. Logistic regression models were used to identify risk factors for both AKI and death. Of 6,011 records, 3,807 were included for analysis after excluding patients with missing data. AKI occurred in 474 (12.5%) patients and 112 (2.9%) died. More patients with versus without AKI died (n=62 [13.1%] vs n=50 [1.5%]; P<0.001). After adjustment, AKI was a predictor of mortality (OR, 5.14; 95% CI, 3.33-7.93; P<0.001). Predictors of AKI were age, African American race, injury severity score, amputations, burns, and presenting vital signs. AKI diagnoses limited to creatinine-based definitions. AKI predicted mortality in combat veterans injured in the wars in Iraq and Afghanistan.

The critical care air transport experience

There have been over 8000 documented patients transported by US Air Force critical care air transport teams (CCATT) since the beginning of US military involvement in Iraq and Afghanistan (Ingalls et al. in JAMA 149:807–13, 2014). As part of the joint service, integrated and multi-tiered aeromedical evacuation system (AES), critically ill or injured service members are transported by CCATT on tactical (short range, within a theatre of operations) and strategic (long range, between theatres of operation) missions. Within the AE system, patients move through five echelons of care, beginning with care at the point of injury and culminating at major military medical centers in the United States. Patients with critical injuries sustained during support of Operation Iraqi Freedom (OIF) or Operation Enduring Freedom (OEF) are first transported to Landstuhl Regional Medical Center (LRMC) in Germany where they are further stabilized for transport back to US facilities. Flight times between evacuation hospitals within the theatre of operations and LRMC can be as long as nine hours. During transport, CCATT monitor patients and continue ongoing resuscitation and treatment plans. Teams are equipped and prepared to intervene should emergent care be required. Critical patients transported to LRMC will often undergo further surgery and frequently require ICU level care with CCATT for transport from LRMC back to the USA. During the peak of conflicts in Iraq and Afghanistan, aeromedical evacuation of critical patients from the point of injury back to the US typically took 2–4 days (Dorlac et al. in J Trauma 66:S164–71, 2009). The paradigm of transporting “stabilizing” patients, even those with severe traumatic injuries over transcontinental distances and often just hours after initial damage control surgery, is supported by a 0.02 % en route mortality rate and a 98 % survival rate among individuals wounded in OIF/OEF that are transported back to LRMC (Ingalls et al. in JAMA 149:807–13, 2014). The long-range transport of critical patients in the austere environment of a military aircraft creates unique challenges for the transport team and is a vital part of the evolving globally mobile medical support apparatus. This article describes both the role of Air Force CCATT within the context of the integrated military AES and the CCATT mission experience in the deployed environment. The role of specialized transport teams and the expanding role of CCATT in a variety of noncombat operations will also be discussed.

Complication Rates in Altitude Restricted Patients Following Aeromedical Evacuation.

Military aeromedical evacuation, especially that associated with the present Middle East conflict, is seeing increasing research. This ecological study initiates research into the validating flight surgeon by looking at cabin altitude restriction (CAR), arguably the validating flight surgeon's prescription with the highest patient-mission impact, and its association with postflight complications. CAR rates from January 2006 through February 2008 were determined from the U.S. Transportation Command Regulating and Command and Control Evacuation System database. Postflight complication rates-the rate of patients with postflight complications (PFC) and the postflight complications per 100 patients (PFC-100)-from January 2007 through June 2008 were calculated from the Landstuhl Regional Medical Center trauma database. CAR and complication rates were examined before, during, and after the authors' deployment. In addition, the relationship between CAR and postflight complication rates was investigated; as the rates were nonlinear, a Spearman correlation was performed. CAR rates during the authors' deployments were significantly up compared to the authors' predecessors or successors; their predecessors and successors did not differ statistically. Likewise, the PFC rate during the authors' deployments was significantly lower than that of the before or after time frames. Furthermore, a statistically significant inverse relationship between CAR and PFC rates (Spearman rho = -0.587) as well as CAR and PFC-100 rates (Spearman rho = -0.568) was demonstrated. CAR rate was inversely correlated to PFC and PFC-100 rates. This finding suggests that aggressive prescribing of CARs may have a salutary effect on postflight complication rates and bears further investigation.

Hypoxemia during aeromedical evacuation of the walking wounded.

Hypobaric hypoxemia is a well-known risk of aeromedical evacuation (AE). Validating patients as safe to fly includes assessment of oxygenation status as well as oxygen-carrying capability (hemoglobin). The incidence and severity of hypoxemia during AE of noncritically injured casualties have not been studied. Subjects deemed safe to fly by the validating flight surgeon were monitored with pulse oximetry from the flight line until arrival at definitive care. All subjects were US military personnel or contractors following traumatic injuries. Noninvasive oxygen saturation (SpO2), pulse rate, and noninvasive hemoglobin were measured every 5 seconds and recorded to electronic memory. Patient demographics and physiologic data were collected by chart abstraction from the Air Force Form 3899, patient movement record. The incidence and duration of hypoxemic events (SpO2 < 90%) and critical hypoxemic events were determined (SpO2 < 85%). Sixty-one casualties were evaluated during AE from Bagram Air Base to Landstuhl Regional Medical Center. The mean (SD) age was 26.2 (6) years, Injury Severity Score (ISS) was 8 (11), and mean SpO2 before AE was 96% (2%). The mean (SD) transport time was 9.3 (1.3) hours. Patients were monitored before AE for a brief period, yielding a total recording time of 10.28 hours. The mean (SD) hemoglobin at the time of enrollment was 13.2 (3.5) g/dL (9.4-18.0 g/dL). Hypoxemia (SpO2 < 90%) was seen in 55 (90%) of 61 subjects. The mean duration of SpO2 less than 90% was 44 minutes. The mean (SD) change in SpO2 from baseline to mean in-flight SpO2 was 4% (1.2%). Thirty-four patients (56%) exhibited an SpO2 less than 85% for 11.7 (15) minutes. Hypoxemia is a common event during AE of casualties. In patients with infection and concussion or mild traumatic brain injury, this could have long-term consequences. Epidemiologic/prognostic study, level V.

Su1567 Nasojejunal Feeding Tube Placement Technique Utilizing Through-the-Scope Advancement: a Simple Technique Maximizing Distal Placement

Landstuhl Regional Medical Center (LRMC) in Germany serves as a major waypoint for casualties evacuated from combat operations. They experience increased catabolic stress due to severity of injuries, blood loss, stress, and lack of caloric intake. Enteral feeding strategies offer benefits of enterocyte nutrition and decreased translocation of gut bacteria into the bloodstream. Distally-placed nasojejunal feeding tubes (NJFT) facilitate enteral nutrition with minimized aspiration risk and interruption for surgical procedures.