Serum uric acid (SUA) is a product of xanthine oxidase (XO). Apoptosis and tissue hypoxia lead to increased purine catabolism, which, in turn, increases XO activity and subsequently SUA levels. The purpose of this study was to perform a meta-analysis to evaluate the evidence supporting SUA as a predictor of all-cause mortality in patients with heart failure (HF) and to determine the SUA cut-off for the increase in risk. A search of the MEDLINE database (1966 to March 2009) supplemented by manual searches of bibliographies of key relevant articles was performed. The authors selected all cohort studies in which SUA was measured and mortality was reported in patients with HF. The pooled relative risk (RR) with the corresponding 95% confidence interval (CI) for all-cause mortality using the fixed-effects method was calculated. The effects of SUA on all-cause mortality at different SUA cut-offs using meta-regression was evaluated. The search strategy yielded 358 studies, of which only 6 met our eligibility criteria. The studies, however, comprised 1456 evaluable patients with HF, with a median ejection fraction of 32% (range, 26%-40%). The RR of all-cause mortality was 2.13 (95% CI, 1.78-2.55) for SUA>6.5 mg/dL compared with <6.5 mg/dL SUA level. There was a linear association (P<.01) between SUA and mortality after 7 mg/dL. Uric acid is an important prognostic marker for all-cause mortality in HF. SUA levels >7 mg/dL are associated with higher all-cause mortality.

Pneumomediastinum (PM) is defined as the presence of free air in the mediastinal cavity. It is often regarded as a revealing sign of a more serious medical condition. PM is broken down into two categories, one, with an instigating event, referred to as secondary PM. The other is when free air is discovered in the mediastinal cavity without a clear etiology, referred to as spontaneous pneumomediastinum (SPM). Often misdiagnosed due to the vague nature of presenting symptoms, SPM must be part of the differential diagnosis of a chest pain patient to expedite discovery and if necessary, management. A MedLine/PubMED search was performed identifying all relevant articles with “SPM” in the title. Six case series were reviewed to determine what clinical scenario constitutes a possible case of SPM. Results showed that almost all patients with SPM exhibited some chest pain, but Hamman’s crunch was present in only one-fifth of patients. Patients with certain pre-existing pulmonary diseases showed a greater propensity for the presence of free air in the mediastinal cavity. SPM must be diagnosed and managed promptly due to rare, but serious complications and any chest pain with an unknown etiology should contain SPM in the differential diagnosis.

Splenectomy predisposes patients to a slew of infectious and non-infectious complications including pulmonary vascular disease. Patients are at increased risk for venous thromboembolic events due to various mechanisms that may lead to chronic thromboembolic pulmonary hypertension (CTEPH). The development of CTEPH and pulmonary vasculopathy after splenectomy involves complex pathophysiologic mechanisms, some of which remain unclear. This review attempts congregate the current evidence behind our understanding about the etio-pathogenesis of pulmonary vascular disease related to splenectomy and highlight the controversies that surround its management.

Caregiver’s burden is a multidimensional phenomenon affecting care-givers physically, emotionally and socially. It is critical to examine the burden of caregivers, because of the complex responsibility they have with their partners. There are relatively few studies that have examined factors linked with psychological burden amongst caregivers of pulmonary arterial hypertension (PAH) patients. Hence, it is pertinent to develop a good understanding of these factors and develop appropriate management strategies, modified to assist PAH caregivers.