From the Guidelines
Paroxysmal nocturnal dyspnea (PND) is a condition that requires immediate medical attention and is most commonly caused by heart failure, which can be managed with medications such as diuretics, ACE inhibitors, beta-blockers, and aldosterone antagonists, as well as lifestyle modifications. The condition is characterized by sudden awakening from sleep with severe shortness of breath, typically occurring 1-2 hours after lying down, and is often associated with orthopnea and edema, as indicated by patient history and physical examination findings 1. Management of PND includes treating the underlying heart failure, and immediate relief can be achieved by sitting upright or standing, which reduces venous return to the heart. Some key medications used to treat heart failure include diuretics, such as furosemide, ACE inhibitors, like lisinopril, beta-blockers, such as metoprolol, and aldosterone antagonists, like spironolactone, as part of a comprehensive treatment plan 1. Lifestyle modifications are essential, including:
- Elevating the head of the bed with pillows or blocks (6-8 inches)
- Limiting fluid intake in the evening
- Following a low-sodium diet (less than 2g daily)
- Avoiding alcohol and large meals before bedtime Patients should seek immediate medical attention if symptoms worsen or don't improve with position changes, as PND can indicate worsening heart failure requiring prompt medical intervention, and diagnostic investigation may be supplemented by chest radiography and electrocardiography (ECG) as well as laboratory testing 1.
From the Research
Definition and Diagnosis of Paroxysmal Nocturnal Dyspnea
- Paroxysmal nocturnal dyspnea (PND) is a common symptom in patients with acute decompensated heart failure (ADHF) 2
- It is characterized by sudden, severe shortness of breath at night, which can be a life-threatening condition 3
- The diagnosis of PND is based on a detailed medical history, physical examination, and complementary evaluations to detect underlying diseases 3
Association with Sleep Apnea and Hemodynamic Changes
- Sleep apnea (SA) is a predisposing cause of PND, associated with overnight worsening hemodynamics in patients with heart failure 2
- The respiratory disturbance index is an independent factor associated with a history of PND, and overnight changes in plasma atrial natriuretic peptide levels are associated with SA 2
Treatment and Management
- Loop diuretics, such as furosemide, are commonly used to treat PND, but their use is associated with increased all-cause mortality and heart failure hospitalization rates, especially at high doses 4
- Nitrate derivatives, such as trinitrine, can improve dyspnea and reduce mortality in patients with myocardial infarction, but their effect on PND is not well established 5
- Non-invasive ventilation can improve physiological parameters, but its effect on mortality and morbidity is uncertain 5
Clinical Significance and Predictive Value
- Orthopnea and PND have limited sensitivity and specificity for diagnosing prevalent heart failure, but their absence can be useful in assembling relatively heart failure-free cohorts for prospective population studies 6
- The use of medications, such as diuretics and vasodilators, can improve the predictive value of orthopnea and PND for diagnosing heart failure 6