Ischemic Colitis in a Patient on Venovenous Extracorporeal Membrane Oxygenation (VV-ECMO) Treatment: An Emerging Complication?

BACKGROUND There have been few reports of colonic ischemia in patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO) treatment, and all patients died during the same hospitalization. CASE REPORT A 48-year-old man was admitted with acute respiratory failure secondary to multifocal pneumonia and required VV-ECMO treatment. He developed abdominal distention and colon dilatation and was subsequently found to have ischemic colitis. He was able to recover from critical illness and ischemic colitis with supportive treatment including colonic decompression. CONCLUSIONS Ischemic colitis is associated with mortality in patients receiving ECMO treatment. The understanding of the pathophysiology is still evolving and requires further research to improve patient outcomes.

Early Results of Fecal Microbial Transplantation Protocol Implementation at a Community-based University Hospital.

INTRODUCTION: Clostridium difficile (CD) is a serious and increasingly prevalent healthcare-associated infection. The pathogenesis of CD infection (CDI) involves the acquisition of CD with a concurrent disruption of the native gut flora. Antibiotics are a major risk although other contributing factors have also been identified. Clinical management combines discontinuation of the offending antibiotic, initiation of CD-specific antibiotic therapy, probiotic agent use, fecal microbiota transplantation (FMT), and surgery as the "last resort" option. The aim of this study is to review short-term clinical results following the implementation of FMT protocol (FMTP) at our community-based university hospital. METHODS: After obtaining Institutional Review Board and Infection Control Committee approvals, we implemented an institution-wide FMTP for patients diagnosed with CDI. Prospective tracking of all patients receiving FMT between July 1, 2015, and February 1, 2017, was conducted using REDCap™ electronic data capture system. According to the FMTP, indications for FMT included (a) three or more CDI recurrences, (b) two or more hospital admissions with severe CDI, or (c) first episode of complicated CDI (CCDI). Risk factors for initial infection and for treatment failure were assessed. Patients were followed for at least 3 months to monitor for cure/failure, relapse, and side effects. Frozen 250 mL FMT samples were acquired from OpenBiome (Somerville, MA, USA). After 4 h of thawing, the liquid suspension was applied using colonoscopy, beginning with terminal ileum and proceeding distally toward mid-transverse colon. Monitored clinical parameters included disease severity (Hines VA CDI Severity Score or HVCSS), concomitant medications, number of FMT treatments, non-FMT therapies, cure rates, and mortality. Descriptive statistics were utilized to outline the study results. RESULTS: A total of 35 patients (mean age 58.5 years, 69% female) were analyzed, with FMT-attributable primary cure achieved in 30/35 (86%) cases. Within this subgroup, 2/30 (6.7%) patients recurred and were subsequently cured with long-term oral vancomycin. Among five primary FMT failures (14% total sample), 3 (60%) achieved medical cure with long-term oral vancomycin therapy and 2 (40%) required colectomy. For the seven patients who either failed FMT or recurred, long-term vancomycin therapy was curative in all but two cases. For patients with severe CDI (HVCSS ≥3), primary and overall cure rates were 6/10 (60%) and 8/10 (80%), respectively. Patients with CCDI (n = 4) had higher HVCSS (4 vs. 3) and a mortality of 25%. Characteristics of patients who failed initial FMT included older age (70 vs. 57 years), female sex (80% vs. 67%), severe CDI (80% vs. 13%), and active opioid use during the initial infection (60% vs. 37%) and at the time of FMT (60% vs. 27%). The most commonly reported side effect of FMT was loose stools. CONCLUSIONS: This pilot study supports the efficacy and safety of FMT administration for CDI in the setting of a community-based university hospital. Following FMTP implementation, primary (86%) and overall (94%) nonsurgical cure rates were similar to those reported in other studies. The potential role of opioids as a modulator of CDI warrants further clinical investigation.

Screening Spirometry in Military Personnel Correlates Poorly with Exercise Tolerance and Asthma History.

BACKGROUND: Spirometry is an easy-to-perform test for evaluating pulmonary symptoms but has several limitations to include adequate test performance for valid results. Spirometry is not recommended to screen a general population for evidence of pulmonary disease unless symptoms are present or longitudinal screening is done for potential occupational exposures. METHODS: A single-spirometry examination was performed on 900 active duty Army soldiers, ages 18-35 yr, without documented respiratory disease. Abnormal studies were identified (obstructive, restrictive, mixed, and flow volume loop abnormalities) and compared with reported respiratory symptoms, smoking history, prior diagnosis of asthma, and failure of the Army physical fitness test 2-mile run using generalized linear modeling techniques. RESULTS: The cohort population had spirometry values comparable with published NHANES III reference values. Ninety-eight subjects (10.9%) were identified with abnormal spirometry included 33 obstructive, 44 restrictive, 3 mixed, and 18 isolated flow volume loop abnormalities. Historical features (smoking, exertional dyspnea, cough, asthma, or APFT failure) had no effect on the probability of an abnormal spirometry result (p = 0.56). Although APFT failure probability is strongly affected by exertional dyspnea (p = 0.00) and current smoking (p = 0.01), abnormal spirometry results did not have a statistically significant effect (p = 0.38). DISCUSSION: For potential screening of military personnel with spirometry to detect pulmonary disease, study findings identified a significant percentage with non-specific abnormalities requiring further evaluation. Spirometry may be indicated in those individuals with a history of asthma or active dyspnea symptoms. Spirometry as a screening tool is poorly (and often incorrectly) predictive for respiratory symptoms or decreased exercise tolerance in a military cohort. CONCLUSION: Spirometry should not be used to screen the military force for the presence of respiratory disorders. In those individuals with a history of asthma, in-depth testing should be performed to fully evaluate any non-specific findings identified during spirometry.

Comparison of virtual bronchoscopy to fiber-optic bronchoscopy for assessment of inhalation injury severity.

PURPOSE: Compare virtual bronchoscopy (VB) to fiberoptic bronchoscopy (FOB) for scoring smoke inhalation injury (SII). METHODS: Swine underwent computerized tomography (CT) with VB and FOB before (0) and 24 and 48 h after SII. VB and FOB images were scored by 5 providers off line. RESULTS: FOB and VB scores increased over time (p<0.001) with FOB scoring higher than VB at 0 (0.30±0.79 vs. 0.03±0.17), 24 h (4.21±1.68 vs. 2.47±1.50), and 48h (4.55±1.83 vs. 1.94±1.29). FOB and VB showed association with PaO2-to-FiO2 ratios (PFR) with areas under receiver operating characteristic curves (ROC): for PFR≤300, VB 0.830, FOB 0.863; for PFR≤200, VB 0.794, FOB 0.825; for PFR≤100, VB 0.747, FOB 0.777 (all p<0.001). FOB showed 80.3% specificity, 77% sensitivity, 88.8% negative-predictive value (NPV), and 62.3% positive-predictive value (PPV) for PFR≤300 and VB showed 67.2% specificity, 85.5% sensitivity, 91.3% NPV, and 53.4% PPV. CONCLUSIONS: VB provided similar injury severity scores to FOB, correlated with PFR, and reliably detected airway narrowing. VB performed during admission CT may be a useful screening tool specifically to demonstrate airway narrowing induced by SII.

Diagnosis and management of chronic lung disease in deployed military personnel.

Military personnel are a unique group of individuals referred to the pulmonary physician for evaluation. Despite accession standards that limit entrance into the military for individuals with various pre-existing lung diseases, the most common disorders found in the general population such as asthma and chronic obstructive pulmonary disease remain frequently diagnosed. Military personnel generally tend to be a more physically fit population who are required to exercise on a regular basis and as such may have earlier presentations of disease than their civilian counterparts. Exertional dyspnea is a common complaint; establishing a diagnosis may be challenging given the subtle nature of symptoms and lack of specificity with pulmonary function testing. The conflicts over the past 10 years in Iraq and Afghanistan have also given rise to new challenges for deployed military. Various respiratory hazards in the deployed environment include suspended geologic dusts, burn pits, vehicle exhaust emissions, industrial air pollution, and isolated exposure incidents and may give rise to both acute respiratory symptoms and chronic lung disease. In the evaluation of deployed military personnel, establishing the presence of actual pulmonary disease and the relationship of existing disease to deployment is an ongoing issue to both military and civilian physicians. This paper reviews the current evidence for chronic lung disease in the deployed military population and addresses any differences in diagnosis and management.

Comparison of airway pressure release ventilation to conventional mechanical ventilation in the early management of smoke inhalation injury in swine.

OBJECTIVE: The role of airway pressure release ventilation in the management of early smoke inhalation injury has not been studied. We compared the effects of airway pressure release ventilation and conventional mechanical ventilation on oxygenation in a porcine model of acute respiratory distress syndrome induced by wood smoke inhalation. DESIGN: Prospective animal study. SETTING: Government laboratory animal intensive care unit. PATIENTS: Thirty-three Yorkshire pigs. INTERVENTIONS: Smoke inhalation injury. MEASUREMENTS AND MAIN RESULTS: Anesthetized female Yorkshire pigs (n = 33) inhaled room-temperature pine-bark smoke. Before injury, the pigs were randomized to receive conventional mechanical ventilation (n = 15) or airway pressure release ventilation (n = 12) for 48 hrs after smoke inhalation. As acute respiratory distress syndrome developed (PaO2/Fio2 ratio <200), plateau pressures were limited to <35 cm H2O. Six uninjured pigs received conventional mechanical ventilation for 48 hrs and served as time controls. Changes in PaO2/Fio2 ratio, tidal volume, respiratory rate, mean airway pressure, plateau pressure, and hemodynamic variables were recorded. Survival was assessed using Kaplan-Meier analysis. PaO2/Fio2 ratio was lower in airway pressure release ventilation vs. conventional mechanical ventilation pigs at 12, 18, and 24 hrs (p < .05) but not at 48 hrs. Tidal volumes were lower in conventional mechanical ventilation animals between 30 and 48 hrs post injury (p < .05). Respiratory rates were lower in airway pressure release ventilation at 24, 42, and 48 hrs (p < .05). Mean airway pressures were higher in airway pressure release ventilation animals between 6 and 48 hrs (p < .05). There was no difference in plateau pressures, hemodynamic variables, or survival between conventional mechanical ventilation and airway pressure release ventilation pigs. CONCLUSIONS: In this model of acute respiratory distress syndrome caused by severe smoke inhalation in swine, airway pressure release ventilation-treated animals developed acute respiratory distress syndrome faster than conventional mechanical ventilation-treated animals, showing a lower PaO2/Fio2 ratio at 12, 18, and 24 hrs after injury. At other time points, PaO2/Fio2 ratio was not different between conventional mechanical ventilation and airway pressure release ventilation.

Inflammatory mediators in smoke inhalation injury.

Smoke inhalation occurs in 10% to 30% of patients admitted to burn centers, and increases mortality by a maximum of 20% over that predicted by age and extent of cutaneous burn alone. Pneumonia in these patients then further increases mortality by a maximum of 40%. While one estimate suggested that 75% of deaths following burn injury may be accounted for by inhalation injury, more recent cohort studies have suggested there is a decreasing mortality attributable to inhalation injury. As part of understanding and improving outcomes from burn injuries, the pathophysiology and inflammatory processes involved in smoke inhalation injury has been extensively investigated in animal models. This review will emphasize the inflammatory pathways involved in inhalation injury, and targeted methods used to treat this injury in both experimental and human models.

Development of a deployment course for graduating military internal medicine residents.

Graduates of military internal medicine residency programs are required to have the necessary knowledge and skills to function as internists, military physicians, and military medical leaders. The global war on terrorism has increased the role internists are playing in combat theaters as they fill multiple different military medical positions including battalion, brigade, and division surgeons as well as physicians in echelon I, II, and III medical facilities. Along with general internists, internal medicine subspecialists, pediatricians, and family physicians also fill these roles. Although internal medicine training provides a broad-based knowledge to care for adults, it does not provide significant training in combat casualty care, detainee health care, or environmental health. To overcome many of these perceived shortfalls, we developed the 3-day deployment course for graduating internal medicine residents outlined in this article. Through a combination of didactic and hands-on training, militarily relevant medical knowledge and skills necessary to function at echelon I and II levels of care were provided. Residents uniformly accepted the course with measurable increase in their fund of knowledge at the completion of the course.