Acute eosinophilic pneumonia in the deployed military setting.

Rationale: Acute eosinophilic pneumonia (AEP) is a rare but important cause of severe respiratory failure most typically caused by cigarette smoking, but can also be caused by medications, illicit drugs, infections and environmental exposures. There is growing evidence that disease severity varies and not all patients require mechanical ventilation or even supplemental oxygen.

Objectives: To compare patients with AEP treated at Landstuhl Regional Medical Center (LRMC) to those in other published series, and to provide recommendations regarding diagnosis and treatment of AEP.

Health care response to CCHF in US soldier and nosocomial transmission to health care providers, Germany, 2009.

In 2009, a lethal case of Crimean-Congo hemorrhagic fever (CCHF), acquired by a US soldier in Afghanistan, was treated at a medical center in Germany and resulted in nosocomial transmission to 2 health care providers (HCPs). After his arrival at the medical center (day 6 of illness) by aeromedical evacuation, the patient required repetitive bronchoscopies to control severe pulmonary hemorrhage and renal and hepatic dialysis for hepatorenal failure. After showing clinical improvement, the patient died suddenly on day 11 of illness from cerebellar tonsil herniation caused by cerebral/cerebellar edema.

Vocal cord dysfunction related to combat deployment.

Objectives: Several etiologies for vocal cord dysfunction (VCD), a syndrome of dyspnea, noisy breathing, and inspiratory vocal cord closure are suggested; there is no consensus on the predisposition to its development. One previously identified psychiatric etiology is combat stress.

Methods: A retrospective review of military personnel evaluated at Landstuhl Regional Medical Center with a new VCD diagnosis post-deployment was conducted.

Transportable extracorporeal lung support for rescue of severe respiratory failure in combat casualties.

Background: Advances in oxygenator membrane, vascular cannula, and centrifugal pump technologies led to the miniaturization of extracorporeal lung support (ECLS) and simplified its insertion and use. Support of combat injuries complicated by severe respiratory failure requires critical care resources not sustainable in the deployed environment. In response to this need, a unique international military-civilian partnership was forged to create a transportable ECLS capability to rescue combat casualties experiencing severe respiratory failure.

Diffuse alveolar hemorrhage: a rare manifestation of trauma.

Objective: Fat emboli syndrome (FES) is a disorder associated with both acute lung injury and acute respiratory distress syndrome. Both FES and diffuse alveolar hemorrhage (DAH) are bronchoscopically definable entities that may share a common etiology. We conducted a chart review analysis to examine the relationship between FES and DAH.

The introduction of extracorporeal membrane oxygenation to aeromedical evacuation.

Objective: To review the principles of extracorporeal membrane oxygenation (ECMO) and to describe the recent advancements in ECMO technology that permit use of this rescue therapy for severe lung injury in combat casualties.

Methods/results: Lung protective ventilation has defined the state-of-the-art treatment for acute lung injury for more than a decade. Despite the benefits provided by a low tidal volume strategy, lung injury patients may experience deterioration in gas exchange to the point that other rescue interventions are needed or the patient succumbs to progressive respiratory failure.

Closing the "care in the air" capability gap for severe lung injury: the Landstuhl Acute Lung Rescue Team and extracorporeal lung support.

Background: The success of US Air Force Critical Care Air Transport Teams (CCATT) in transporting critically ill and injured patients enabled changes in military medical force deployment and casualty care practice. Even so, a subset of casualties remains who exceed even CCATT capabilities for movement. These patients led to the creation of the Landstuhl Acute Lung Rescue Team (ALeRT) to close the "care in the air" capability gap.

Reversal of hemorrhagic shock-associated hepatic ischemia-reperfusion injury with N-acetylcysteine.

Background: The underpinning pathophysiology, prevalence, and clinical relevance particular to hemorrhagic shock-induced liver damage have been explored only recently. Importantly, several investigators have revealed that an aberrant periportal endothelial response, characterized by the early release of oxidizing mediators, perpetuates and eventually amplifies the extent of hepatic reperfusion injury.

Case: We present a case that illustrates the clinical impact of hepatic ischemia-reperfusion injury and a potential means of ameliorating the attendant self-propagating hepatic destruction.

A review of the surgical treatment options for the obstructive sleep apnea/hypopnea syndrome patient.

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a medical condition that has received significant attention within the medical community and mainstream media due to its potentially serious physiological consequences and relatively frequent occurrence within the general population. From the military perspective, the impact on individual readiness for deployment, and the potential degradation of performance in critically important military duties, often results in tremendous expenditures of training resources, time, and expertise to replace the military member with a suitable substitute or release of the individual from active duty. This article reviews common surgical techniques for clinical management of OSAHS patients in a presentation format for primary care and sleep medicine specialists, as well as surgeons interested in the philosophies of surgical management of sleep disordered breathing.

Predictors of early acute lung injury at a combat support hospital: a prospective observational study.

Background: Acute lung injury (ALI) is a syndrome consisting of noncardiogenic acute hypoxemic respiratory failure with the presence of bilateral pulmonary infiltrates and occurs in up to 33% of critically ill trauma patients. Retrospective and observational studies have suggested that a blood component resuscitation strategy using equal ratios of packed red blood cells (PRBCs) and fresh frozen plasma (FFP) may have a survival benefit in combat casualties. The purpose of this study was to determine whether this strategy is associated with an increased incidence of ALI.

Combat-associated drowning.

Background: The purpose of this article is to describe the clinical course and outcome of drowning cases related to current US military combat operations.

Methods: This retrospective case series spans December 2002 to January 2009 of survivors transferred to an echelon IV military trauma center in Europe serving as the primary evacuation hub for ongoing combat operations. Patient demographics and the situational and clinical findings at the initial drowning scene were reviewed.

High-frequency percussive ventilation and low tidal volume ventilation in burns: a randomized controlled trial.

Objectives: In select burn intensive care units, high-frequency percussive ventilation is preferentially used to provide mechanical ventilation in support of patients with acute lung injury, acute respiratory distress syndrome, and inhalation injury. However, we found an absence of prospective studies comparing high-frequency percussive ventilation with contemporary low-tidal volume ventilation strategies. The purpose of this study was to prospectively compare the two ventilator modalities in a burn intensive care unit setting.

High-frequency percussive ventilation revisited.

High-frequency percussive ventilation (HFPV) has demonstrated a potential role as a rescue option for refractory acute respiratory distress syndrome and as a method for improving inhalation injury outcomes. Nevertheless, there is a lack of literature examining the practical application of HFPV theory toward either improving gas exchange or preventing possible ventilator-induced lung injury. This article will discuss the clinically pertinent aspects of HFPV, inclusive of high- and low-frequency ventilation.

Intercontinental aeromedical evacuation of patients with traumatic brain injuries during Operations Iraqi Freedom and Enduring Freedom.

Traumatic brain injury contributes significantly to military combat morbidity and mortality. No longer maintaining comprehensive medical care facilities throughout the world, the US military developed a worldwide trauma care system making the patient the moving part of the system. Life-saving interventions are performed early, and essential care is delivered at forward locations.

High-frequency percussive ventilation: pneumotachograph validation and tidal volume analysis.

Introduction: High-frequency percussive ventilation (HFPV) is an increasingly used mode of mechanical ventilation, for which there is no proven real-time means of measuring delivered tidal volume (V(T)).

Objective: To validate a pneumotachograph for HFPV and then exploit flow-sensor data to describe the behavior of both low-frequency and high-frequency breaths.

Methods: Sensor performance was gauged during changes in high-frequency (4-12 Hz) and low-frequency rate and ratio, mean airway pressure, oxygen concentration, heated or heated-humidified gas flow, and endotracheal tube diameter.

Inhaled prostacyclin in combination with high-frequency percussive ventilation.

We present a case of severe acute respiratory distress syndrome pursuant to inhalation of a compressed gas computer keyboard cleaner. Despite the use of multimodal therapy to include empiric antibiotics, intravenous paralytics, intravenous concentrated albumin, high-dose corticosteroids as well as sustained high mean airway pressure mechanical ventilation by airway pressure release and high-frequency percussive ventilation (HFPV) modes, the patient demonstrated an unchanging arterial oxygen tension/fraction of inspired oxygen ratio of only 57 mm Hg. A trial of nebulized prostacyclin was initiated during HFPV leading to a significant improvement in arterial oxygen tension/fraction of inspired oxygen to 147 mm Hg.

Cardiopulmonary exercise test interpretation using age-matched controls to evaluate exertional dyspnea.

Background: Cardiopulmonary exercise testing (CPET) is one method to diagnose unexplained dyspnea in young adults, yet few normal reference values exist in this population. This study evaluated interpretation of maximal CPET in a young adult cohort with known pulmonary disorders using published reference values compared to age-matched normal controls.

Methods: A control population of 69 healthy military volunteers with normal chest radiographs, pulmonary function testing, and bronchoprovocation testing were compared to 105 patients with exertional dyspnea.

Feasibility study of noninvasive ventilation with helium-oxygen gas flow for chronic obstructive pulmonary disease during exercise.

Background: Individually, noninvasive ventilation (NIV) and helium-oxygen gas mixtures (heliox) diminish ventilatory workload and improve exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). NIV in combination with heliox may have additive effects on exercise tolerance in severe COPD.

Methods: We assessed the safety, tolerability, and efficacy of heliox and NIV during exercise in patients with severe COPD.

Airway humidification during high-frequency percussive ventilation.

Background: We were concerned about the risk of inadequate humidification during high-frequency percussive ventilation (HFPV).

Methods: We studied 5 humidifiers during HFPV with a lung model, at bias gas flows of 10 L/min, 30 L/min, and 50 L/min, and compared the results to those from a comparator ventilator/humidifier setup and to the minimum temperature (30 degrees C) and humidity (30 mg/L) [corrected] recommended by the American Association for Respiratory Care, at both regular room temperature and a high ambient temperature. Temperature was measured at the humidifier outflow point and at the artificial carina.

Critical care at Landstuhl Regional Medical Center.

Background: Landstuhl Regional Medical Center is the largest U.S. medical facility outside the United States, and it is the first permanently positioned hospital outside the combat zone providing care to the wartime sick and wounded.

Randomized placebo controlled assessment of airway inflammation due to racemic albuterol and levalbuterol via exhaled nitric oxide testing.

Study Objectives: The S-stereoisomer found in racemic albuterol may have associated proinflammatory properties. We tested the hypothesis that airway inflammation as assessed by exhaled nitric oxide is no different in patients with COPD when using racemic albuterol relative to levalbuterol or placebo.

Measurements: Twelve mild to moderate COPD patients were assigned to five days each of nebulized racemic albuterol, levalbuterol, and saline placebo.

Systematic review of the chronic care model in chronic obstructive pulmonary disease prevention and management.

Background: Implementation of the chronic care model (CCM) has been shown to be an effective preventative strategy to improve outcomes in diabetes mellitus, depression, and congestive heart failure, but data are lacking regarding the effectiveness of this model in preventing complications in patients with chronic obstructive pulmonary disease.

Methods: We searched the MEDLINE, CINAHL, and Cochrane databases from inception to August 2005 and included English-language articles that enrolled adults with chronic obstructive pulmonary disease and (1) contained intervention(s) with CCM component(s), (2) included a comparison group or measures at 2 points (before/after), and (3) had relevant outcomes. Two reviewers independently extracted data.

Corrective measures for compromised oxygen delivery during endotracheal tube cuff deflation with high-frequency percussive ventilation.

Objective: To determine the effect of endotracheal-tube cuff deflation on airflow and F(IO2) during high-frequency percussive ventilation (HFPV), and explore methods of correcting the cuff-deflation-associated decrease in mean airway pressure and F(IO2) at the carina.

Methods: Using a mechanical lung model in our respiratory research laboratory, we measured circuit pressure near the connection to the endotracheal tube (P(vent)), mean airway pressure (P(aw)), pulsatile tidal volume (V(T)), and F(IO2) at the artificial carina. During cuff deflation we manipulated the pulsatile frequency, pulsatile flow, and the HFPV integral nebulizer.

Measurement of pulsatile tidal volume, pressure amplitude, and gas flow during high-frequency percussive ventilation, with and without partial cuff deflation.

Objective: With a high-frequency percussive ventilator and a mechanical lung model, to measure tidal volume (V(T)), pulsatile pressure amplitude (difference between peak and nadir pulsatile pressure [DeltaP];), and mean airway pressure (P (aw)) at various pulsatile frequencies, pulsatile inspiratory-expiratory ratios (I:E(p)), and pressures (measured at the interface between the pulse-generator and the endotracheal tube [P(vent)]).

Methods: With the endotracheal tube inside an artificial trachea, we manipulated the high-frequency percussive ventilation settings and adjuncts, including pulsatile frequency, I:E(p), and P(vent) by manipulating pulsatile flow. We also studied the effects of partially deflating the endotracheal tube cuff.