Debapriya Datta

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation from the narrowing of small airways and damage to lung parenchyma, resulting in exercise intolerance. Cardiopulmonary exercise testing (CPET) provides a comprehensive assessment of exercise capacity and of the integrated responses of the respiratory, cardiovascular, muscular and metabolic systems. It helps clinicians understand the mechanisms of dyspnea, informs treatment decisions and can evaluate the effectiveness of pulmonary rehabilitation and other treatments. CPET can also detect coexisting conditions, such as heart failure, myopathy or deconditioning, that worsen exercise intolerance in COPD despite treatment. Recognizing these comorbidities allows them to be investigated and treated in their own right. Because CPET is resource-intensive, it is best used selectively, as a phenotyping and problem-solving tool, and it is important that pulmonologists know when to request it and how to interpret it. In this review, the mechanisms of exercise limitation in COPD and the physiological measurements obtained during CPET are described, and the CPET patterns that distinguish ventilatory limitation from cardiac, pulmonary vascular and other causes of exercise intolerance are compared. Testing protocols, the interpretation of results in relation to bronchodilator therapy, and safety and contraindications are summarized. Developments since previous reviews and guidelines on COPD and lung cancer fitness, as well as recent evidence on ventilatory efficiency and prognosis are highlighted, with emphasis on integrative interpretation. Clinical applications are illustrated with an algorithm and a case example, and limitations, cost, barriers to implementation and future research are discussed.

Background/Objectives: Despite documented benefits across multiple outcome areas, referral and uptake into pulmonary rehabilitation (PR) following discharge after an exacerbation of chronic obstructive pulmonary disease (COPD) is low in many health care systems. Surveys documenting this underutilization may ignore the fact of disease severity or comorbidity severe enough to make many patients ineligible based on accepted selection criteria for the intervention. The aim of this study was to evaluate the magnitude of non-eligibility for PR following discharge after a COPD exacerbation. Methods: Medical records of COPD patients discharged over a one-year period in two hospitals were reviewed. Records from 353 patients discharged home were reviewed by six clinicians with experience in respiratory medicine and/or PR, three at each hospital. Results: The mean age of the total sample was 71 ± 12 years; 53% were female. Full concordance (all three reviewers agreed on the eligibility or non-eligibility of each patient) was 73%. Our eligibility criterion (two of three reviewers agreed) for PR was 39%. Categories (%) of non-eligibility criteria included the severity of medical condition(s) (44%), cognitive problems, psychiatric disease or substance abuse (24%), incorrect diagnosis (18%), institutionalized post-discharge (9%), and language barriers (4%) (patients may have been placed into more than one criteria category). Conclusions: Our study indicates that a majority of patients with clinical diagnoses of COPD discharged following exacerbations may not be appropriate referrals to PR based on accepted inclusion and/or exclusion criteria for the intervention. However, even after taking this into account, PR uptake is still critically underutilized.

A 66-year-old man who had been diagnosed with mild coronavirus 2019 (COVID-19) infection nine days prior presented to the emergency room with acute-onset chest pain and shortness of breath. Chest CT angiogram (CTA) revealed pulmonary emboli (PE) in the right and left pulmonary arteries with right heart strain; lung parenchyma showed no infiltrates. Although severe COVID-19 infection is associated with thrombotic complications, data regarding the occurrence of PE in mild cases of COVID-19 is scarce. However, even mild cases of COVID-19 are reported to have revealed lung infiltrates, particularly ground-glass opacities, on imaging. The possibility of the lungs being the primary source of COVID-19-associated coagulopathy has been raised. We report an uncommon case of submassive PE occurring in mild COVID-19, without any associated lung infiltrates. This case indicates that mild COVID-19, without significant lung parenchymal involvement, can also cause a hypercoagulable state, resulting in venous thromboembolism (VTE).

Acute chest syndrome (ACS), a vaso-occlusive crisis in patients with sickle cell anemia, is a life-threatening condition and a leading cause of death in these patients. It is treated with analgesics, antibiotics, intravenous fluid, supplemental oxygen (or ventilatory support in severe cases) with simple or exchange transfusion, being the mainstay of therapy. We report a young Jehovah’s Witness (JW) patient with sickle cell anemia who presented with ACS. Her religious beliefs precluded the use of blood products. Despite concomitant hemolytic and aplastic crisis and a hemoglobin nadir of 3.1 g/dL, the patient was treated successfully with supportive care - including mechanical ventilation, sedation, paralysis, and erythropoiesis stimulation - and survived. A maximal supportive strategy consisting of ventilatory support with a high fraction of inspired oxygen, sedation, paralysis, erythropoiesis stimulation, and limitation of blood draws can result in the successful treatment of JW patients who refuse blood products.