Epidemiology

Hemoptysis is defined as the expectoration of blood from the respiratory tract below the vocal cords. Most cases seen in the emergency department (ED) are mild episodes of small-volume hemoptysis, typically consisting of either blood-tinged sputum or minute amounts of frank blood and are most commonly caused by bronchitis. Although hemoptysis is commonly seen in the ED, only 1 to 5% of hemoptysis patients have massive or life-threatening hemorrhage (generally accepted as 100 to 600 mL of blood loss in any 24-hour period), which can result in hemodynamic instability, shock, or impaired alveolar gas exchange and has a mortality rate approaching 80%.

Large, contemporary series of patients with massive hemoptysis are lacking, and most causative data originate from small, often rural, studies in which tuberculosis (TB) and bronchiectasis are responsible for the majority of cases.¹ In developed nations, cancer, cystic fibrosis, arteriovenous malformations, and postprocedural complications play more prominent roles. Pediatric hemoptysis is rare but can be caused by infection, congenital heart disease, cystic fibrosis, or bleeding from a preexisting tracheostomy.²

Pathophysiology

Trace hemoptysis typically originates from tracheobronchial capillaries that are disrupted by vigorous coughing or minor bronchial infections. Conversely, massive hemoptysis nearly always involves disruption of bronchial or pulmonary arteries, the two sets of vessels that constitute the lung’s dual blood supply. Bronchial arteries, which are direct branches from the thoracic aorta, are responsible for supplying oxygenated blood to lung parenchyma, and disruption of these vessels from arteritis, trauma, bronchiectasis or malignant erosion can result in sudden and profound hemorrhage. Although small in caliber, the bronchial circulation is a high-pressure system and the culprit in nearly 90% of the cases of massive hemoptysis requiring embolization. Pulmonary arteries, although transmitting large volumes of blood, do so at much lower pressures and, unless affected centrally, are less likely to cause massive hemoptysis.

Nearly all causes of hemoptysis have a common mechanism—vascular disruption within the trachea, bronchi, small-caliber airways, or lung parenchyma. Modes of vessel injury include acute and chronic inflammation (from bronchitis and arteritis), local infection (especially lung abscesses, TB, and aspergillosis), trauma, malignant invasion, infarction following a pulmonary embolus, and fistula formation (specifically aortobronchial fistulae).

Bronchiectasis, a chronic necrotizing infection resulting in bronchial wall inflammation and dilation, is one of the most common causes of massive hemoptysis. As tissue destruction and remodeling occur, rupture of nearby bronchial vessels can result in bleeding. Bronchiectasis can complicate chronic airway obstruction, necrotizing pneumonia, TB, or cystic fibrosis. Broncholithiasis, the formation of calcified endobronchial lesions following a wide array of granulomatous infections, is an uncommon problem with a similar propensity to erode nearby vessels. Hemorrhage control often requires surgical intervention.3–5

Iatrogenic hemoptysis complicates 2 to 10% of all endobronchial procedures, especially percutaneous lung biopsies.6,7 Diffuse alveolar hemorrhage can be seen with autoimmune vasculitides such as Wegener’s granulomatosis, systemic lupus erythematosus, and Goodpasture’s syndrome. An uncommon cause of hemoptysis occurs when ectopic endometrial tissue within the lung results in monthly catamenial episodes of bleeding.⁸ Less common causes include pulmonary hereditary telangiectasias and hydatidiform infections. Any episode of hemoptysis can be exacerbated by coagulopathy and thrombocytopenia.

Differential Considerations

For a patient with apparent hemoptysis, two other potential sources of bleeding should be investigated. Nasal, oral, or hypopharyngeal bleeding sometimes contaminates the tracheobronchial tree, mimicking true hemoptysis. The clinician should closely inspect the nasopharynx and oral cavity to exclude this possibility. Gastric or proximal duodenal bleeding can similarly mimic hemoptysis, and differentiating a gastrointestinal (GI) source of bleeding is especially important because further evaluation and management of these two pathologies follow divergent pathways. Usually differentiation can be done by the patient and physician working together to differentiate coughing from vomiting. In unclear cases, inspection and pH testing may help to distinguish GI from tracheobronchial hemorrhage. Unless an active, brisk upper GI hemorrhage is present, the acidification of blood in the stomach results in fragmentation and darkening, producing specks of brown or black material often referred to as coffee-ground emesis. Pulmonary blood appears bright red or as only slightly darker clots and is alkaline.

Rapid Assessment and Stabilization

Although hemodynamic instability can occur as a result of hemorrhage, the most lethal sequela of massive hemoptysis is hypoxia, which results from the ventilation-perfusion mismatch that follows submersion of the small airways and alveoli with blood.

As a mitigating maneuver in patients with a known lateralizing source of bleeding, the “lung-down” position can be employed. For this position the patient is turned such that the bleeding lung is more dependent, promoting continued protection and ventilation of the unaffected lung and improved oxygenation. If intubation is required, a large diameter (8.0) endotracheal tube should be used to facilitate emergent fiberoptic bronchoscopy. In selected cases of confirmed left-sided bleeding, a single-lumen right-mainstem intubation often can be successfully performed through advancement of the tube in the neutral position or use of a 90-degree rotational technique, during which the tube is rotated 90 degrees in the direction of desired placement and advanced until resistance is met.⁹ Left-mainstem intubations are more difficult but may be attempted when the bleeding site is the right lung and simple lung-down positioning is not sufficient to stabilize the patient’s airway and oxygenation.

When these measures fail or the hemoptysis is life-threatening, anesthesia consultation is sought for consideration of placement of a double-lumen endotracheal tubes for lung isolation. The correct positioning of blindly placed double-lumen tubes is difficult and requires confirmation by auscultation and fiberoptic bronchoscopy, both of which have are severely impaired by massive hemoptysis. Complications of double-lumen tubes include unilateral and bilateral pneumothoraces, pneumomediastinum, carinal rupture, lobar collapse, and tube malposition.¹⁰