EpistemisDyspnea induced by left lateral decubitus
Specialty: Respiratory.
Why it occurs
- Massive right pleural effusion (when adopting the left decubitus position, the right fluid exerts gravitational pressure on the mediastinum, compromising the expansion of the healthy left lung)
- Unilateral left diaphragmatic paralysis (diaphragmatic laxity allows free visceral ascent towards the left chest when lying on that side due to gravity)
- Megacardiomegaly or extreme dilated heart disease (the massive heart displaces and compresses the left lung parenchyma and the left main bronchus when lying on that side)
- Obstructive neoplasia of the right main bronchus
- Left basal pulmonary arteriovenous fistula.
Initial workup
Anteroposterior and lateral chest x-ray; Dynamic diaphragmatic ultrasound to assess contractility and left inspiratory thickness; High-resolution chest computed tomography (CT) with vascular protocol; Functional echocardiogram evaluating cardiac volumes and geometric interaction of ventricles with posture.
red flags
Tachypnea greater than 30 breaths per minute when adopting the position, acute ipsilateral pleuritic pain, new onset postural cardiac arrhythmias, severe arterial desaturation refractory to low oxygen flows, or profuse diaphoresis.
Standard management
- Strict postural adjustment avoiding the left lateral decubitus position
- Supportive treatment with oxygen therapy
- Furosemide — 40 mg intravenously if there is fluid overload with right pleural effusion
- Spironolactone (25 mg orally daily as part of the management of underlying heart failure).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Respiratory
- Listed causes
- 5
- Treatment options
- 4