The need to provide invasive mechanical ventilatory support to patients with myocardial infarction and acute left heart failure is common. Despite the large number of patients requiring mechanical ventilation in this setting, there are remarkably few data addressing the ideal mode of respiratory support in such patients. Although there is near universal acceptance regarding the use of non-invasive positive pressure ventilation in patients with acute pulmonary oedema, there is more concern with invasive positive pressure ventilation owing to its more significant haemodynamic impact. Positive end-expiratory pressure (PEEP) is almost universally applied in mechanically ventilated patients due to benefits in gas exchange, recruitment of alveolar units, counterbalance of hydrostatic forces leading to pulmonary oedema and maintenance of airway patency. The limited available clinical data suggest that a moderate level of PEEP is safe to use in severe left ventricular (LV) dysfunction and cardiogenic shock, and may provide haemodynamic benefits as well in LV failure which exhibits afterload-sensitive physiology.

In patients on diuretics, fractional excretion of urea should be used in preference to fractional excretion of sodium.

Critical illness due to 2009 H1N1 influenza has been characterized by respiratory complications, including acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), and associated with high mortality. We studied the severity, outcomes, and hospital charges of patients with ALI/ARDS secondary to pandemic influenza A infection compared with ALI and ARDS from other etiologies.

Background: Cardiopulmonary exercise testing (CPET) is a valuable diagnostic and prognostic tool for assessing the integrated function of the cardiopulmonary and muscular systems during exercise. The initiation of a CPET program is complex, and data on early implementation in academic centers remain relatively limited. Objective: to evaluate the initial integration of CPET within a pulmonary department, focusing on patient demographics, referral indications, test performance, and factors associated with anaerobic threshold achievement. Methods: A retrospective cohort study was conducted at a single tertiary care center, including all patients who underwent their first CPET between February 2016 and December 2022. Demographic, clinical, and functional parameters were extracted. Multivariable logistic regression was used to identify variables associated with anaerobic threshold achievement, defined as a respiratory exchange ratio (RER) ≥ 1.1. Results: The cohort included 434 patients (mean age 60.3 ± 14.1 years; 54% male; mean BMI 29.2 ± 5.6 kg/m²). The most common indication for testing was dyspnea (50%). Tests were most frequently terminated due to leg discomfort (39%) and dyspnea (38.8%). Achievement of RER ≥ 1.1 was independently associated with lower BMI (aOR = 0.91; 95% CI: 0.88–0.95; p < 0.001), higher FVC % predicted (aOR = 1.02; 95% CI: 1.00–1.03; p = 0.028), and greater minute ventilation volume (aOR = 1.02; 95% CI: 1.01–1.03; p < 0.001), and it was less likely in patients referred for cardiovascular disease (aOR = 0.37; 95% CI: 0.21–0.64; p < 0.001). No consistent temporal trend in RER achievement was observed across the study period. Conclusions: CPET was most commonly utilized in response to patient-reported dyspnea, with test termination frequently driven by subjective symptoms rather than objective clinical criteria. Anaerobic threshold achievement was more strongly associated with individual physiological characteristics than with institutional experience. These findings underscore the importance of patient preparation and pulmonary functional capacity in optimizing CPET performance.