Infective endocarditis in adults with congenital heart disease remains a lethal disease.

OBJECTIVE: Infective endocarditis (IE) is associated with significant morbidity and mortality. Patients with adult congenital heart disease (ACHD) have an increased risk of developing IE. The aim of this study is to describe the incidence, predictors of outcome and mortality associated with IE in ACHD in a contemporary cohort. METHODS: All episodes of IE in adults with congenital heart disease referred to our tertiary centre between 1999 and 2013 were included in the study. Patients were identified from the hospital database. The diagnosis of endocarditis was established according to the modified Duke criteria. The primary endpoint of the study was endocarditis-associated mortality. RESULTS: There were 164 episodes of IE in 144 patients (male 102, 70.8%). Mean age at presentation was 32.3±22.7 years. Out of these, 43% had a simple, 23% a moderate and 32% a complex lesion. It was at least the second bout of IE in 37 episodes (23%). A predisposing event could be identified in only 26.2% of episodes. Surgical intervention during the same admission was performed in 61 episodes (37.2%). During a median follow-up of 6.7 years (IQR 2.9-11.4), 28 (19.4%) patients died. Out of these, 10 deaths were related to IE (IE mortality 6.9%). On unvariate regression analysis, the development of an abscess (OR: 7.23; 95% CI 1.81 to 28.94, p<0.01) and age (OR: 1.05; 95% CI 1.01 to 1.10, p=0.03) were the only predictors of IE-associated mortality. There was no increase in IE cases at our centre during the period of the study. CONCLUSIONS: IE-associated morbidity and mortality in a contemporary cohort of ACHD patients is still high in the current era.

Identifying orthopedic patients at high risk for venous thromboembolism despite thromboprophylaxis.

OBJECTIVE: To evaluate risk factors for venous thromboembolism (VTE) despite thromboprophylaxis in major orthopedic surgery patients at a tertiary care hospital. METHODS: Charts from consecutive patients who underwent total hip replacement (THR), total knee replacement (TKR), or hip fracture surgery (HFS) [hip pinning or hemiarthroplasty] from August 1, 1999, to April 30, 2000, at a large Canadian teaching hospital were abstracted using standardized case report forms. Data were collected on patient characteristics, surgical characteristics, and thromboprophylaxis regimen. Results of tests performed for suspected VTE were documented. Associations between characteristics of interest and objectively confirmed VTE were examined in multivariate analysis. RESULTS: Over the study period, 310 patients underwent major orthopedic surgery and received standard thromboprophylaxis with either dalteparin or enoxaparin (mean duration of prophylaxis, 7 days). Of these, 34% underwent THR, 30% underwent TKR, and 36% underwent HFS. Of 83 suspected cases of VTE, 44 cases (7 proximal and 37 distal deep venous thrombosis [DVT]); 14% of study population) were confirmed with objective testing. Multivariate analyses revealed that knee surgery (odds ratio [OR], 4.8; 95% confidence interval [CI], 2.3 to 10.1) and type of low molecular weight heparin (LMWH) [enoxaparin (more protective): OR, 0.39; 95% CI, 0.20 to 0.80] independently predicted VTE. No patient characteristics (including previous VTE, malignancy, hormonal therapy, postoperative complications) were associated with VTE. CONCLUSION: Despite standard thromboprophylaxis, symptomatic breakthrough VTE, primarily distal DVT, developed in 14% of patients undergoing major orthopedic surgery. Factors that independently predicted VTE in our population were TKR surgery and type of LMWH. TKR patients may warrant more aggressive postoperative physiotherapy and ambulation and adjunctive prophylactic measures such as pneumatic compression. Due to the heterogeneity of different LMWH compounds, direct comparison of the effectiveness of enoxaparin with dalteparin for orthopedic prophylaxis in prospective, randomized trials seems warranted.

Altitude-related hypoxia: risk assessment and management for passengers on commerical aircraft.

BACKGROUND: Individuals with pulmonary and cardiac disorders are particularly at risk of developing hypoxemia at altitude. Our objective is to describe the normal and maladaptive physiological responses to altitude-related hypoxia, to review existing methods and guidelines for preflight assessment of air travelers, and to provide recommendations for treatment of hypoxia at altitude. DATA SYNTHESIS: Falling partial pressure of oxygen with altitude results in a number of physiologic adaptations including hyperventilation, pulmonary vasoconstriction, altered ventilation/perfusion matching, and increased sympathetic tone. According to three guideline statements, the arterial pressure of oxygen (PaO2) should be maintained above 50 to 55 mm Hg at all altitudes. General indicators such as oxygen saturation and sea level blood gases may be useful in predicting altitude hypoxia. More specialized techniques for estimation of altitude PaO2, such as regression equations, hypoxia challenge testing, and hypobaric chamber exposure have also been examined. A regression equation using sea level PaO2 and spirometric parameters can be used to estimate PaO2 at altitude. Hypoxia challenge testing, performed by exposing subjects to lower inspired FIO2 at sea level may be more precise. Hypobaric chamber exposure, the gold standard, mimics lower barometric pressure, but is mainly used in research. CONCLUSION: Oxygen supplementation during air travel is needed for individuals with an estimated PaO2 (8000 ft) below 50 mmHg. There are a number of guidelines for the pre-flight assessment of patients with pulmonary and/or cardiac diseases. However, these data are based on small studies in patients with a limited group of diseases.