Review: Hemodynamic Characteristics and Outcomes of Sickle Cell Disease Associated Pulmonary Hypertension.

Pulmonary hypertension (PH) is a leading cause of morbidity and early mortality in adults with sickle cell disease (SCD). However, the prevalence, hemodynamic profile and prognosis of SCD-PH remain controversial and need frequent updates. Pulmonary hypertension determined by right heart catheterization (RHC) occurs in 6% to 10% of adults with SCD. Hemodynamically, SCD-PH may be pre-capillary or post-capillary in nature. The exact etiology is unknown and often multifactorial; hence a thorough diagnostic evaluation following established PH guidelines is essential to determine disease prevalence, etiology and outcomes. Data on the efficacy and safety of pulmonary arterial hypertension (PAH) therapy are limited in SCD; clinical trials in these patients are urgently needed. This review provides an overview of RHC-determined hemodynamic characteristics, current management modality and outcomes; we also highlight recent advances and unmet research needs in SCD-PH.

Obesity and Pulmonary Function in African Americans.

BACKGROUND: Obesity prevalence in United States (US) adults exceeds 30% with highest prevalence being among blacks. Obesity is known to have significant effects on respiratory function and obese patients commonly report respiratory complaints requiring pulmonary function tests (PFTs). However, there is no large study showing the relationship between body mass index (BMI) and PFTs in healthy African Americans (AA). OBJECTIVE: To determine the effect of BMI on PFTs in AA patients who did not have evidence of underlying diseases of the respiratory system. METHODS: We reviewed PFTs of 339 individuals sent for lung function testing who had normal spirometry and lung diffusion capacity for carbon monoxide (DLCO) with wide range of BMI. RESULTS: Functional residual capacity (FRC) and expiratory reserve volume (ERV) decreased exponentially with increasing BMI, such that morbid obesity resulted in patients breathing near their residual volume (RV). However, the effects on the extremes of lung volumes, at total lung capacity (TLC) and residual volume (RV) were modest. There was a significant linear inverse relationship between BMI and DLCO, but the group means values remained within the normal ranges even for morbidly obese patients. CONCLUSIONS: We showed that BMI has significant effects on lung function in AA adults and the greatest effects were on FRC and ERV, which occurred at BMI values < 30 kg/m2. These physiological effects of weight gain should be considered when interpreting PFTs and their effects on respiratory symptoms even in the absence of disease and may also exaggerate existing lung diseases.

Forging a critical alliance: Addressing the research needs of the United States critical illness and injury community.

OBJECTIVE: Discuss the research needs of the critical illness and injury communities in the United States. DATA SOURCES: Workshop session held during the 5 National Institutes of Health Symposium on the Functional Genomics of Critical Illness and Injury (November 15, 2007). STUDY SELECTION: The current clinical research infrastructure misses opportunities for synergy and does not address many important needs. In addition, it remains challenging to rapidly and properly implement system-wide changes based upon reproducible evidence from clinical research. DATA EXTRACTION: Author presentations, panel discussion, attendee feedback. DATA SYNTHESIS: The critical illness and injury research communities seek better communication and interaction, both of which will improve the breadth and quality of acute care research. Success in meeting these needs should come from cooperative and strategic actions that favor collaboration, standardization of protocols, and strong leadership. An alliance framed on common goals will foster collaboration among experts to better promote clinical trials within the critically ill or injured patient population. CONCLUSIONS: The U.S. Critical Illness and Injury Trials Group was funded to create a clinical research framework that can reduce the barriers to investigation using an investigator-initiated, evidence-driven, inclusive approach that has proven successful elsewhere. This alliance will provide an annual venue for systematic review and strategic planning that will include framing the research agenda, raising awareness for the value of acute care research, gathering and promoting best practices, and bolstering the critical care workforce.