Characterizing the Asthma Phenotype of Military Personnel.

INTRODUCTION: Asthma is the most common diagnosis in military personnel who endorse chronic dyspnea. Service members have unique occupational risk factors, and there is concern that airborne exposures in the deployed environment as well as other occupational exposures may contribute to the development of asthma or exacerbate pre-existing disease. Asthma phenotyping with clinical biomarkers such as serum immunoglobulin E (IgE) levels and eosinophil (EOS) counts is useful in defining treatment strategies for the management of asthma. This study sought to characterize the phenotype of medically separated military personnel with career-limiting asthma to define potential management strategies and guide future research evaluating the unexplained prevalence of asthma in this population. MATERIALS AND METHODS: A retrospective chart review of active duty service members (ADSM) who underwent fitness for duty evaluation via medical evaluation board between 2005 and 2016 and were separated with a minimum 30% conditional disability rating for asthma was performed. Only ADSM who were diagnosed with asthma by a pulmonologist and had spirometry data available were included in the analysis. Demographics, spirometry data, and laboratory data to include IgE levels, radioallergosorbent panels, and EOS counts were analyzed from the DoD electronic medical record. RESULTS: A total of 141 service members were evaluated with a mean age of 42 ± 6.8 years, mean serum EOS count of 300 ± 358 cells/µL, and mean IgE level of 305 ± 363 IU/mL. The patients were further categorized into 4 subgroups based on serum EOS count and IgE level: group A with IgE < 100 IU/mL and EOS < 300 cells/µL (n = 45; 33%), group B with IgE > 100 IU/mL and EOS < 300 cells/µL (n = 44; 32%), group C with IgE < 100 IU/mL and EOS > 300 cells/µL (n = 6; 1%), and group D with IgE > 100 IU/mL, EOS > 300 cells/µL (n = 46; 34%). Among the cohorts, there were no statistically significant differences in demographics, body mass index, spirometry, smoking history, or disability rating. CONCLUSION: The majority of ADSM with a defined asthma history do not have concordant elevations in serum IgE and blood EOS suggestive of a Th2-high phenotype. Asthma in this population is heterogeneous, and phenotyping using clinical biomarkers may be useful to define optimal treatment strategies.

Bronchoalveolar Lavage Fluid Cytology of Deployed Military Personnel With Chronic Respiratory Symptoms From the STAMPEDE III Study.

INTRODUCTION: Deployed military personnel may be at risk for developing acute and chronic lung disease. Prior studies of this patient population have revealed that unexplained exertional dyspnea is the most common diagnosis despite an extensive evaluation. There is a concern that an occult disorder may be affecting this population. This study evaluated the role for bronchoalveolar lavage (BAL) fluid analysis in the evaluation of chronic deployment-associated dyspnea. MATERIALS AND METHODS: Military personnel who reported chronic respiratory symptoms were evaluated as part of the Study of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures III study. Participants underwent bronchoscopy with BAL as part of a standardized evaluation. RESULTS: A total of 308 patients with a mean age of 38 ± 8.6 years underwent bronchoscopy with BAL. BAL cell-count percentages of macrophages, lymphocytes, neutrophils, and eosinophils were: 76.2 ± 17.0%, 16.3 ± 13.4%, 6.6 ± 8.9%, and 0.9 ± 3.2%, respectively. There was no clear differentiation between groups based on increases in lymphocyte counts (P = .640), although lymphocyte values were more elevated (21.4 ± 12.1%) in the interstitial lung disease category. Neutrophil counts (6.6 ± 8.9%) were elevated compared to the reported normal reference values and were increased in the isolated pulmonary function test abnormality (9.4 ± 11.6%), large airway disorder (10.0 ± 7.5%), miscellaneous (10.9 ± 20.2%), and obstructive lung disease (11.0 ± 15.6%) groups. Eosinophil counts were within normal limits (0.9 ± 3.2%) and showed no differences between groups (P = .545); asthma patients trended higher (1.6 ± 5.7%). BAL counts for the exertional dyspnea group were within normal reference values and showed no differences from the entire cohort. CONCLUSIONS: The addition of BAL cytology did not help differentiate those patients with unexplained dyspnea from other etiologies.

Correlation between positive airway pressure and medication adherence: the healthy user effect.

STUDY OBJECTIVES: Despite the efficacy of positive airway pressure (PAP) for the treatment of obstructive sleep apnea, adherence remains challenging and negatively affects assessments of effectiveness. It is unclear whether low adherence is due to intolerance of PAP or whether this reflects overall adherence with medical therapy. We sought to correlate PAP use with medication adherence to determine whether poor adherence with PAP was specific to this treatment or represented global compliance with medical therapy. METHODS: A total of 600 consecutive patients with obstructive sleep apnea were treated with PAP. Objective measures of PAP use were correlated with medication adherence. We included all chronically used medications, defined as medications used daily for at least 90 days prior to PAP initiation. Medication use was verified using an electronic health record. PAP adherence ("regular use") was defined as PAP use for ≥ 4 hours/night on ≥ 70% of nights. Medication adherence was defined as > 70% of pills taken as prescribed. RESULTS: Complete records were available for 566 patients; 361 (63.8%) used chronic medications. The cohort was primarily men (90.3%, age 44.6 ± 10.2 years) with moderate obstructive sleep apnea (apnea-hypopnea index, 18.1 ± 13.9 events/h). In patients on chronic medications, PAP was used 55.8% of nights and 37.7% were regular users. Patients who were adherent with medications used PAP more hours/night (5.4 vs 4.6, P < .001) and were more likely to have regular PAP use compared with those nonadherent with medications (P = .04). CONCLUSIONS: Adherence with PAP correlated with adherence to chronic medications. Low PAP adherence may reflect an individual's global adherence to medical care. This association may lead to better identification of patients who benefit from targeted therapy to improve overall health care adherence. CITATION: Lettieri MJ, Warren WA, Walter RJ, Lettieri CJ. Correlation between positive airway pressure and medication adherence: the healthy user effect. J Clin Sleep Med. 2024;20(7):1087-1092.

Beyond Trauma: High-Volume Critical Care Medicine in a Military Medical Center-Based Military-Civilian Partnership.

INTRODUCTION: Critical Care Internal Medicine (CCIM) is vital to the U.S. Military as evidenced by the role CCIM played in the COVID-19 pandemic response and wartime operations. Although the proficiency needs of military surgeons have been well studied, this has not been the case for CCIM. The objective of this study was to compare the patient volume and acuity of military CCIM physicians working solely at Military Treatment Facilities (MTFs) with those at MTFs also working part-time in a military-civilian partnership (MCP) at the University Medical Center of Southern Nevada (UMC). MATERIALS AND METHODS: We analyzed FY2019 critical care coding data from the Military Health System and UMC comparing the number of critical care encounters, the number of high-acuity critical care encounters, and the Abilities/Activity component of the Knowledge, Skills, and Abilities/Clinical Activity (KSA) score. This analysis was restricted to critical care encounters defined by Current Procedural Terminology codes for critical care (99291 and 99292). A critical care encounter was considered high acuity if the patient had ICD-10 codes for shock, respiratory failure, or cardiac arrest or had at least three codes for critical care in the same episode. RESULTS: The five AF CCIM physicians in the MCP group performed 2,019 critical care encounters in 206 days, with 63.1% (1,273) being defined as high acuity. The total number of MTF critical care encounters was 16,855 across all providers and services, with 28.9% (4,864) of encounters defined as high acuity. When limited to CCIM encounters, MTFs had 6,785 critical care encounters, with 32.0% being high acuity (2,171). Thus, the five AF CCIM physicians, while working 206 days at the UMC, equated to 12.0% (2,019/16,855) of the total critical care MTF encounters, 27.2% (1,273/4,684) of the total high-acuity MTF critical care encounters, and 29.8% (2,019/6,785) of the MTF CCIM encounters, with 58.6% (1,273/2,171) of the MTF CCIM high-acuity encounters.The USAF CCIM physicians in the MCP group performed 454,395 KSAs in 206 days, with a KSA density per day of 2,206. In the MTF group, CCIM providers generated 2,344,791 total KSAs over 10,287 days, with a KSA density per day of 227.9. Thus, the five CCIM physicians at the UMC accounted for 19.38% of the MTF CCIM KSAs, with a KSA density over 10 times higher (2,206 vs. 227.9). CONCLUSIONS: The volume and acuity of critical care at MTFs may be insufficient to maintain CCIM proficiency under the current system. Military-civilian partnerships are invaluable in maintaining clinical proficiency for military CCIM physicians and can be done on a part-time basis while maintaining beneficiary care at an MTF. Future CCIM expeditionary success is contingent on CCIM physicians and team members having the required CCIM exposure to grow and maintain clinical proficiency.Limitations of this study include the absence of off-duty employment (moonlighting) data and difficulty filtering military data down to just CCIM physicians, which likely caused the MTF CCIM data to be overestimated.

Financial and Clinical Impact of Virtual Care During the COVID-19 Pandemic: Difference-in-Differences Analysis.

BACKGROUND: Virtual care (VC) and remote patient monitoring programs were deployed widely during the COVID-19 pandemic. Deployments were heterogeneous and evolved as the pandemic progressed, complicating subsequent attempts to quantify their impact. The unique arrangement of the US Military Health System (MHS) enabled direct comparison between facilities that did and did not implement a standardized VC program. The VC program enrolled patients symptomatic for COVID-19 or at risk for severe disease. Patients' vital signs were continuously monitored at home with a wearable device (Current Health). A central team monitored vital signs and conducted daily or twice-daily reviews (the nurse-to-patient ratio was 1:30). OBJECTIVE: Our goal was to describe the operational model of a VC program for COVID-19, evaluate its financial impact, and detail its clinical outcomes. METHODS: This was a retrospective difference-in-differences (DiD) evaluation that compared 8 military treatment facilities (MTFs) with and 39 MTFs without a VC program. Tricare Prime beneficiaries diagnosed with COVID-19 (Medicare Severity Diagnosis Related Group 177 or International Classification of Diseases-10 codes U07.1/07.2) who were eligible for care within the MHS and aged 21 years and or older between December 2020 and December 2021 were included. Primary outcomes were length of stay and associated cost savings; secondary outcomes were escalation to physical care from home, 30-day readmissions after VC discharge, adherence to the wearable, and alarms per patient-day. RESULTS: A total of 1838 patients with COVID-19 were admitted to an MTF with a VC program of 3988 admitted to the MHS. Of these patients, 237 (13%) were enrolled in the VC program. The DiD analysis indicated that centers with the program had a 12% lower length of stay averaged across all COVID-19 patients, saving US $2047 per patient. The total cost of equipping, establishing, and staffing the VC program was estimated at US $3816 per day. Total net savings were estimated at US $2.3 million in the first year of the program across the MHS. The wearables were activated by 231 patients (97.5%) and were monitored through the Current Health platform for a total of 3474 (median 7.9, range 3.2-16.5) days. Wearable adherence was 85% (IQR 63%-94%). Patients triggered a median of 1.6 (IQR 0.7-5.2) vital sign alarms per patient per day; 203 (85.7%) were monitored at home and then directly discharged from VC; 27 (11.4%) were escalated to a physical hospital bed as part of their initial admission. There were no increases in 30-day readmissions or emergency department visits. CONCLUSIONS: Monitored patients were adherent to the wearable device and triggered a manageable number of alarms/day for the monitoring-team-to-patient ratio. Despite only enrolling 13% of COVID-19 patients at centers where it was available, the program offered substantial savings averaged across all patients in those centers without adversely affecting clinical outcomes.

Outcomes of Fungemia in Patients Receiving Extracorporeal Membrane Oxygenation.

There are limited data on the treatment of fungal infections complicating extracorporeal membrane oxygenation (ECMO). In 14 patients who developed fungal bloodstream infections on ECMO, 8 (57%) survived to discharge. Of the 5 patients completing treatment prior to decannulation, 2 (40%) developed recurrent fungal infections.

The Effect of Deployment on Pulmonary Function in Military Personnel With Asthma.

INTRODUCTION: Military personnel with a diagnosis of asthma report increased respiratory symptoms in the deployment and post-deployment periods. The long-term effect of deployment on pulmonary function in this population is unknown. This study sought to determine the effect of deployment on post-deployment pulmonary function in active duty military personnel with asthma. MATERIALS AND METHODS: A retrospective chart review of active duty military personnel with deployment to southwest Asia and an ICD-9 diagnosis of asthma with documented pre- and post-deployment spirometry was performed. RESULTS: A total of 642 active duty individuals with a diagnosis of asthma and documented spirometry with deployment to southwest Asia between 2006 and 2015 were identified. Of these, 76 individuals were identified with pre- and post-deployment spirometry. There was no significant change in the post-deployment forced expiratory volume at 1 second (% predicted), from 86.0 ± 14.8 to 87.6 ± 14.4 (P = .30). There was no significant change in post-deployment forced vital capacity (% predicted), from 93.8 ± 12.4 to 94.9 ± 12.1 (P = .42). The absolute change in forced expiratory volume at 1 second (L) after bronchodilator administration was decreased from pre-deployment to post-deployment (+0.31 ± 0.26 to +0.16 ± 0.23; P = .02). CONCLUSIONS: There was no significant post-deployment change in spirometry in this military population with asthma deployed to southwest Asia. These findings suggest that deployment itself is not associated with any short-term deleterious effect on post-deployment spirometric measures of lung function in many military personnel with asthma.

Longitudinal Changes in Spirometry in Deployed Air Force Firefighters.

INTRODUCTION: Inhalational exposures are common among service members who deploy to southwest Asia. The objective of this study is to determine if deployed Air Force firefighters have any decline in spirometry related to deployment. METHODS: This study is a retrospective chart review. RESULTS: The database search identified 302 firefighters with documentation of two separate spirometry examinations. For deployed firefighters, mean change in forced expiratory volume at 1 second (FEV1) percent predicted was -1.01 ±â€Š7.86, forced vital capacity (FVC) was -0.46 ±â€Š10.26 predicted, and mid-expiratory flow (FEF25-75) was -0.13 ±â€Š12.97. For firefighters who had never deployed, mean change in FEV1 percent predicted was +0.08 ±â€Š7.09, FVC was +0.72 ±â€Š7.75, and FEF25-75 was -0.66 ±â€Š16.17. CONCLUSION: There does not appear to be evidence that deployment causes a significant change in lung function as measured by spirometry.

Adjunct Use of Continuous Renal Replacement Therapy with Extracorporeal Membrane Oxygenation Achieves Negative Fluid Balance and Enhances Oxygenation Which Improves Survival in Critically Ill Patients without Kidney Failure.

INTRODUCTION: Fluid overload in extracorporeal membrane oxygenation (ECMO) patients has been associated with increased mortality. Patients receiving ECMO and continuous renal replacement therapy (CRRT) who achieve a negative fluid balance have improved survival. Limited data exist on the use of CRRT solely for fluid management in ECMO patients. METHODS: We performed a single-center retrospective review of 19 adult ECMO patients without significant renal dysfunction who received CRRT for fluid management. These patients were compared to a cohort of propensity-matched controls. RESULTS: After 72 h, the treatment group had a fluid balance of -3840 mL versus + 425 mL (p ≤ 0.05). This lower fluid balance correlated with survival to discharge (odds ratio 2.54, 95% confidence interval 1.10-5.87). Improvement in the ratio of arterial oxygen content to fraction of inspired oxygen was also significantly higher in the CRRT group (102.4 vs. 0.7, p ≤ 0.05). We did not observe any significant difference in renal outcomes. CONCLUSIONS: The use of CRRT for fluid management is effective and, when resulting in negative fluid balance, improves survival in adult ECMO patients without significant renal dysfunction.

Evaluation of Supranormal Spirometry Values With an Obstructive Ratio for Airway Hyperreactivity.

BACKGROUND: Published guidelines on spirometry interpretation suggest an elevated FVC and FEV1 > 100% of predicted with an obstructive ratio may represent a physiological variant. Further evidence is needed on whether this finding indicates symptomatic airways obstruction and what additional evaluation should be done. METHODS: Participants were prospectively enrolled to undergo additional testing for a technically adequate spirometry study with an FEV1 > 90% of predicted, and FEV1/FVC below the lower limit of normal, based on 95th percentile confidence intervals. Further testing consisted of full pulmonary function testing, impulse oscillometry (IOS), post-bronchodilator testing, fractional exhaled nitric oxide (FeNO), and methacholine challenge testing (MCT). RESULTS: A total of 49 patients meeting entry criteria enrolled and completed testing. Thirty-three were considered symptomatic based on clinical indications for initial testing and 16 were considered asymptomatic. Baseline pulmonary function test values were not different between groups while IOS R5 values (% predicted) were higher in the symptomatic group (126.5 ± 0.37 vs 107.1 ± 0.31). Bronchodilator responsiveness on PFT or IOS was infrequent in both groups. There was a 29% positivity rate for MCT in the symptomatic group compared to one borderline study in asymptomatic participants. FeNO was similar for symptomatic, 26.17 ± 31.3 ppb, compared to asymptomatic, 22.8 ± 13.5 ppb (p = 0.93). The dysanapsis ratio was higher in the symptomatic (0.15 ± 0.03) compared to the asymptomatic (0.13 ± 0.02) (p < 0.05). CONCLUSION: Normal FEV1 > 90% of predicted and obstructive indices may not represent a normal physiological variant in all patients. In symptomatic patients, a positive MCT and elevated baseline IOS values were more common than in asymptomatic patients with similar PFT characteristics. These findings suggest that clinicians should still evaluate for airway hyperresponsiveness in patients with exertional dyspnea with airway obstruction and FEV1 > 90% of predicted and consider alternative diagnoses to include a normal physiologic variant if non-reactive.

Argatroban for Anticoagulation in Patients Requiring Venovenous Extracorporeal Membrane Oxygenation in Coronavirus Disease 2019.

A significant proportion of patients with coronavirus disease 2019 requiring venovenous extracorporeal membrane oxygenation at our institution demonstrated heparin resistance, which in combination with a heparin shortage resulted in the transition to argatroban with or without aspirin as an alternative anticoagulation strategy. The optimal anticoagulation strategy for coronavirus disease 2019 patients requiring venovenous extracorporeal membrane oxygenation is unknown, and therefore, we sought to evaluate the efficacy and safety of argatroban with or without aspirin as an alternative anticoagulation strategy in this patient population. DESIGN: Retrospective cohort. SETTING: Single-center tertiary-care facility in Fort Sam Houston, TX, from 2020 to 2021. PATIENTS: Twenty-four patients who were cannulated for venovenous extracorporeal membrane oxygenation due to respiratory failure secondary to coronavirus disease 2019. INTERVENTIONS: Argatroban, with or without aspirin, was substituted for heparin in coronavirus disease 2019 patients requiring venovenous extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: Eighty percent of our coronavirus disease 2019 patients requiring venovenous extracorporeal membrane oxygenation demonstrated heparin resistance, and patients who were initially started on heparin were significantly more likely to require a change to argatroban than vice versa due to difficulty achieving or maintaining therapeutic anticoagulation goals (93.4% vs 11.1%; p < 0.0001). The time to reach the therapeutic anticoagulation goal was significantly longer for patients who were initially started on heparin in comparison with argatroban (24 vs 6 hr; p = 0.0173). Bleeding and thrombotic complications were not significantly different between the two cohorts. CONCLUSIONS: Argatroban, with or without aspirin, is an effective anticoagulation strategy for patients who require venovenous extracorporeal membrane oxygenation support secondary to coronavirus disease 2019. In comparison with heparin, this anticoagulation strategy was not associated with a significant difference in bleeding or thrombotic complications, and was associated with a significantly decreased time to therapeutic anticoagulation goal, likely as a result of high rates of heparin resistance observed in this patient population.

Critical Care Education and Skills Validation Course for Internal Medicine Physicians in the Military.

INTRODUCTION: Military internist and internal medicine (IM) subspecialist physicians must be prepared to function in both traditional inpatient and outpatient settings, as well as manage critically ill patients within a deployed austere environment. As many critical care procedures are not performed on a routine basis in general IM practice, many active duty IM physicians experience skills degradation and lack confidence in performing these procedures. In order to address this perceived deficiency, the U.S. Army and Air Force Internal Medicine Education and Skills Validation Course was developed to provide essential training in critical care procedures for active duty military IM physicians and subspecialists. MATERIALS AND METHODS: Staff internist and subspecialist physicians at multiple military treatment facilities participated in a 2-day simulation-based training course in critical care procedures included in the Army Individual Critical Task Lists and the Air Force Comprehensive Medical Readiness Program. Educational content included high-yield didactic lectures, multi-disciplinary Advanced Cardiac Life Support/Advanced Trauma Life Support high-fidelity simulation scenarios, and competency training/validation in various bedside procedures, including central venous and arterial line placement, trauma-focused ultrasound exam, airway management and endotracheal intubation, chest tube thoracotomy, and mechanical ventilation, among others. RESULTS: A total of 87 staff IM physicians participated in the course with an average of 2-4 years of experience following completion of graduate medical education. Upon course completion, all participants successfully achieved rigorous, checklist-based, standardized validation in all the required procedures. Survey data indicated a significant improvement in overall skills confidence, with 100% of participants indicating improvement in their ability to function independently as deployed medical officers. CONCLUSIONS: Broad implementation of this program at military hospitals would improve pre-deployment critical care procedural readiness in military IM physicians.

Isolated Small Airway Dysfunction and Ventilatory Response to Cardiopulmonary Exercise Testing.

BACKGROUND: The effect of isolated small airway dysfunction (SAD) on exercise remains incompletely characterized. We sought to quantify the relationship between isolated SAD, identified with lung testing, and the respiratory response to exercise. METHODS: We conducted a prospective evaluation of service members with new-onset dyspnea. All subjects underwent plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO), impulse oscillometry, high-resolution computed tomography (HRCT), and cardiopulmonary exercise testing (CPET). In subjects with normal basic spirometry, DLCO, and HRCT, SAD measures were analyzed for associations with ventilatory parameters at submaximal exercise and at maximal exercise during CPET. RESULTS: We enrolled 121 subjects with normal basic spirometry (ie, FEV1, FVC, and FEV1/FVC), DLCO, and HRCT. Mean age and body mass index were 37.4 ± 8.8 y and 28.4 ± 3.8 kg/m2, respectively, and 110 (90.9%) subjects were male. The prevalence of SAD varied from 2.5% to 28.8% depending on whether FEV3/FVC, FEF25-75%, residual volume/total lung capacity, and R5-R20 were used to identify SAD. Agreement on abnormal SAD across tests was poor (kappa = -0.03 to 0.07). R5-R20 abnormalities were related to higher minute ventilation ([Formula: see text]) and higher [Formula: see text]/maximum voluntary ventilation (MVV) during submaximal exercise and to lower [Formula: see text] during maximal exercise. After adjustment for differences at baseline, there remained a trend toward a relationship between R5-R20 and an elevated [Formula: see text]/MVV during submaximal exercise (ß = 0.04, 95% CI -0.01 to 0.09, P = .10), but there was no significant association with [Formula: see text] during submaximal exercise or with [Formula: see text] during maximal exercise. No other SAD measures showed a relationship with ventilatory parameters. CONCLUSIONS: In 121 subjects with normal basic spirometry, DLCO, and HRCT, we found poor agreement across tests used to detect SAD. Among young, healthy service members with postdeployment dyspnea, SAD as identified by lung function testing does not predict changes in the ventilatory response to exercise.

Clinical Evaluation of Deployed Military Personnel With Chronic Respiratory Symptoms: Study of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures (STAMPEDE) III.

BACKGROUND: Chronic respiratory symptoms are frequently reported after Southwest Asia deployment in support of combat operations. The full spectrum of clinical lung diseases related to these deployments is not well characterized. METHODS: Military personnel with chronic symptoms, primarily exertional dyspnea, underwent a standardized cardiopulmonary evaluation at two tertiary medical centers. Pulmonary function testing consisted of spirometry, lung volume, diffusing capacity, impulse oscillometry, and bronchodilator testing. Further testing included methacholine challenge, exercise laryngoscopy, high-resolution CT scan, ECG, and transthoracic echocardiography. RESULTS: A total of 380 participants with a mean age of 38.5 ± 8.4 years completed testing. Asthma was the most common diagnosis in 87 patients (22.9%) based on obstructive spirometry/impulse oscillometry and evidence of airway hyperreactivity, whereas another 57 patients (15.0%) had reactivity with normal spirometry. Airway disorders included 25 (6.6%) with laryngeal disorders and 16 (4.2%) with excessive dynamic airway collapse. Interstitial lung disease was identified in six patients (1.6%), whereas 11 patients (2.9%) had fixed obstructive lung disorders. Forty patients (10.5%) had isolated pulmonary function abnormalities and 16 (4.2%) had miscellaneous disorders. The remaining 122 patients (32.1%) with normal studies were classified as undiagnosed exertional dyspnea. Significant comorbidities identified included elevated BMI > 30 kg/m2 (34.2%), smoking (36.4%), positive allergy testing (43.7%), sleep apnea (38.5%), and esophageal reflux (13.6%). Mental health disorders and posttraumatic stress disorder were likewise common. CONCLUSIONS: Postdeployment pulmonary evaluation should focus on common diseases, such as asthma and airway hyperreactivity, and include testing for upper airway disorders. Diffuse lung diseases were rarely diagnosed, whereas numerous comorbidities were common.

Outcomes among Patients Treated with Renal Replacement Therapy during Extracorporeal Membrane Oxygenation: A Single-Center Retrospective Study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) are modalities used in critically ill patients suffering organ failure and metabolic derangements. Although the effects of CRRT have been extensively studied, the impact of simultaneous CRRT and ECMO is less well described. The purpose of this study is to evaluate the incidence and the impact of CRRT on outcomes of patients receiving ECMO. METHODS: A single center, retrospective chart review was conducted for patients receiving ECMO therapy over a 6-year period. Patients who underwent combined ECMO and CRRT were compared to those who underwent ECMO alone. Intergroup -statistical comparisons were performed using Wilcoxon/Kruskal-Wallis and chi-square tests. Logistic regression was performed to identify independent risk factors for mortality. RESULTS: The demographic and clinical data of 92 patients who underwent ECMO at our center were reviewed including primary diagnosis, indications for and mode of ECMO support, illness severity, oxygenation index, vasopressor requirement, and presence of acute kidney injury. In those patients that required ECMO with CRRT, we reviewed urine output prior to initiation, modality used, prescribed dose, net fluid balance after 72 h, requirement of renal replacement therapy (RRT) at discharge, and use of diuretics prior to RRT initiation. Our primary endpoint was survival to hospital discharge. During the study period, 48 patients required the combination of ECMO with CRRT. Twenty-nine of these patients survived to hospital discharge. Of the 29 survivors, 6 were dialysis dependent at hospital discharge. The mortality rate was 39.5% with combined ECMO/CRRT compared to 31.4% among those receiving ECMO alone (p = 0.074). Of those receiving combined therapy, nonsurvivors were more likely to have a significantly positive net fluid balance at 72 h (p = 0.001). A multivariate linear regression analysis showed net positive fluid balance and increased age were independently associated with mortality. CONCLUSIONS: Use of CRRT is prevalent among patients undergoing ECMO, with over 50% of our patient population receiving combination therapy. Fluid balance appears to be an important variable associated with outcomes in this cohort. Rates of renal recovery and overall survival were higher compared to previously published reports among those requiring combined ECMO/CRRT.

Right Ventricular Failure Following Patent Foramen Ovale Closure on Venovenous-Extracorporeal Membrane Oxygenation.

We present a patient with pulmonary arterial hypertension requiring venovenous-extracorporeal membrane oxygenation for acute respiratory distress syndrome. Refractory hypoxemia secondary to right-to-left interatrial shunting via a patent foramen ovale was discovered. Right heart catheterization with invasive occlusion test heralded worsening right heart failure so closure was aborted. (Level of Difficulty: Intermediate.).

Use of Mortality as an Endpoint in Noninferiority Trials May Lead to Ethically Problematic Conclusions.

BACKGROUND: Noninferiority trials are becoming more common. Their design often requires investigators to "trade" a secondary benefit for efficacy. Use of mortality as an outcome of interest leads to important ethical conflicts whereby researchers must establish a minimal clinically important difference for mortality, a process which has the potential to result in problematic conclusions. OBJECTIVE: We sought to investigate the frequency of the use of mortality as an outcome in noninferiority trials, as well as to determine the average pre-specified noninferiority ("delta") values. DESIGN: We searched MEDLINE for reports of parallel-group randomized controlled noninferiority trials published in five high-impact general medical journals. MAIN OUTCOME MEASURES: Data abstracted from articles including trial design parameters, results, and interpretation of results based on CONSORT recommendations. RESULTS: One hundred seventy-three manuscripts reporting 196 noninferiority comparisons were included in our analysis. Of these, over a third (67 trials) used mortality either as their sole endpoint (11 trials) or as part of a composite endpoint (56 trials). Nine trials were consort A, 21 trials consort B, 19 trials consort C, 12 were consort F, 4 consort G, and 2 were consort H. Four analyses showed statistically significant more deaths in the new treatment arm, while meeting consort criteria as "inconclusive" (consort G), (Behringer et al. in Lancet. 385(9976):1418-1427, 2015; Kaul et al. in N Engl J Med. 373(18):1709-1719, 2015; Bwakura-Dangarembizi et al. in N Engl J Med. 370(1):41-53, 2014) and thirteen trials utilizing mortality as an endpoint and had an absolute increase of > 3%, and six had an absolute increase of > 5%. CONCLUSIONS: The use of mortality as an outcome in noninferiority trials is not rare and scenarios where the new treatment is statistically worse, but a conclusion of noninferiority or inconclusive do occur. We highlight these issues and propose simple steps to reduce the risk of ethically dubious conclusions.

Salvage extracorporeal membrane oxygenation in induction-associated acute respiratory distress syndrome in acute leukemia patients: A case series.

BACKGROUND:: The prognosis of hematologic malignancies has improved over the past three decades. However, the prognosis in hematologic malignancies with severe acute respiratory distress syndrome has remained poor. Initial reports regarding the utility of extracorporeal membrane oxygenation in hematologic malignancies have been controversial, with limited evaluations of acute leukemia patients supported by extracorporeal membrane oxygenation. METHODS:: We conducted a retrospective review of patients with acute leukemia who developed acute respiratory distress syndrome requiring veno-venous extracorporeal membrane oxygenation support at our facility from July 2015 through August 2017. RESULTS:: Four cases of acute myelogenous leukemia with respiratory failure and acute respiratory distress syndrome treated with veno-venous extracorporeal membrane oxygenation while undergoing induction chemotherapy were identified. All patients completed induction therapy with addition of extracorporeal membrane oxygenation support, with two patients dying secondary to their acute leukemia and the other two surviving to allogeneic hematopoietic stem cell transplant. Overall, 75% (three of four) survived to decannulation with a 1-year survival rate following extracorporeal membrane oxygenation of 50% (two of four). CONCLUSION:: Currently, the use of extracorporeal membrane oxygenation in patients with hematologic malignancies who develop severe acute respiratory distress syndrome remains controversial. Although extracorporeal membrane oxygenation in post-allogeneic hematopoietic stem cell transplant is associated with poorer outcomes, our data suggest that salvage extracorporeal membrane oxygenation support is a viable option to manage moderate to severe acute respiratory distress syndrome while completing therapeutic chemotherapy and following in the peri-induction phase of acute leukemia.