From the Guidelines
The next step for this 60-year-old female with persistent shortness of breath despite initial treatment should be a chest CT angiogram to evaluate for pulmonary embolism (PE). Given her history of DVT, aortic valve replacement, and obesity, she has multiple risk factors for PE. The fact that her oxygen saturation improved with supplemental oxygen but did not respond to bronchodilators and steroids suggests this is not primarily an asthma exacerbation, as noted in guidelines for managing asthma exacerbations 1. While awaiting the CT scan, she should remain on oxygen support via nasal cannula to maintain adequate saturation, following the principles outlined for oxygen use in adults in healthcare and emergency settings 1. Blood work including D-dimer, BNP, and troponin should be ordered to help with differential diagnosis. If PE is confirmed, anticoagulation therapy would be indicated, with careful consideration of her valve replacement history which may require consultation with cardiology regarding the appropriate anticoagulant. The lack of fever and normal heart rate make infectious causes less likely, but the persistent hypoxemia despite treatment for asthma raises concern for a thromboembolic event given her significant risk factors.
Key considerations in her management include:
- The use of supplemental oxygen as needed to maintain adequate saturation levels, with careful monitoring to avoid hypercapnia, especially in patients with chronic respiratory conditions 1.
- The importance of diagnosing and managing potential pulmonary embolism given her risk factors and presentation, which may involve consultation with specialists and the use of anticoagulation therapy.
- The role of blood work, including D-dimer and other markers, in helping to differentiate between potential causes of her symptoms.
- The need for a comprehensive approach to her care, considering her complex medical history and the potential for multiple concurrent conditions contributing to her presentation.
Given the information provided and the guidelines for managing patients with potential respiratory and cardiac issues 1, the focus should be on promptly evaluating for PE and managing her oxygen therapy carefully to balance the need for adequate oxygenation with the risk of worsening hypercapnia, if present.
From the Research
Patient Presentation and Initial Treatment
- The patient is a 60-year-old female with a history of deep vein thrombosis (DVT), aortic valve replacement, asthma, and obesity, presenting with shortness of breath (SOB) for 3 days.
- Initial treatment included 2 albuterol nebulizers and dexamethasone, with no improvement in oxygen saturation.
- The patient was then placed on 2L nasal cannula, resulting in improved oxygen saturation.
Considerations for Next Steps
- Given the patient's history of DVT and current presentation, pulmonary embolism (PE) should be considered as a potential diagnosis 2, 3.
- The use of low-molecular-weight heparin (LMWH) is recommended for the treatment of PE, especially in patients with a high risk of recurrence 3, 4.
- The patient's oxygen saturation improved with supplemental oxygen, but further evaluation and treatment are necessary to determine the underlying cause of her symptoms.
Anticoagulation Therapy
- Anticoagulation therapy is essential for patients with PE, and LMWH or non-vitamin K antagonist oral anticoagulants (NOACs) are preferred over unfractionated heparin (UFH) due to their lower risk of bleeding 3, 5.
- The decision to extend anticoagulation therapy should be based on the individual risk of PE recurrence and bleeding 3, 6.
Next Steps
- Further diagnostic evaluation, such as computed tomography (CT) scan or ventilation-perfusion scan, is necessary to confirm the diagnosis of PE.
- If PE is confirmed, anticoagulation therapy with LMWH or NOACs should be initiated, and the patient's response to treatment should be closely monitored 2, 3, 5.