Hemoptysis

1 What is hemoptysis?

Hemoptysis is the expectoration of blood originating from the lower respiratory tract. It is classified on the basis of the volume of expectorated blood.

2 How are hemoptysis and pseudohemoptysis different?

Pseudohemoptysis is expectoration of blood originating from a source other than the lower respiratory tract. It results from either aspiration of blood from the gastrointestinal tract or blood draining into the larynx and trachea from bleeding sites in the oral cavity, nasopharynx, or larynx.

3 Describe the differential diagnosis of hemoptysis

The differential diagnosis of hemoptysis is based on the site of bleeding. Hemoptysis in general results from either a focal or a diffuse tracheobronchial (airway) or pulmonary parenchymal process (Box 25-1). Occasionally nonpulmonary processes, in particular cardiac, vascular, or hematologic disorders, may result in bleeding in the lungs. The frequency with which hemoptysis is associated with these conditions is determined by the age of the patient, the population being studied (e.g., surgical vs. medical, veterans hospital vs. city or county indigent hospital), and the amount of expectorated blood. Approximately 30% of cases are cryptogenic, and no explanation for hemoptysis is determined despite extensive evaluation.

4 What are the common causes of massive hemoptysis?

The most common causes of massive hemoptysis are bronchiectasis, active or inactive tuberculosis, necrotizing pneumonia (including lung abscess) and fungal infections. The latter include both mycetoma (aspergilloma) and, less commonly, chronic necrotizing pulmonary aspergillosis. The relative frequency of these causes has changed in the past few decades and depends on both the institution and country from which the data are reported. Pulmonary neoplasm, arteriovenous malformation, pulmonary vasculitis, valvular heart disease (especially mitral stenosis), and bleeding diathesis are also potential causes of massive hemoptysis but occur less frequently.

5 Name the common iatrogenic causes of hemoptysis that occur in critically ill patients

When hemoptysis begins after endotracheal intubation, upper airway trauma caused by the intubation procedure, endotracheal tube, or endotracheal suction catheters must be considered. If hemoptysis begins after a latent period of 1 or more weeks after intubation, a tracheoartery fistula may be the source of hemorrhage. This possibility is increased if a tracheostomy tube is present. Pulmonary artery rupture and pulmonary infarction should be considered when hemoptysis occurs in a patient with a pulmonary artery catheter. Pulmonary infarction should be suspected if a wedge-shaped infiltrate is present distal to the catheter on the chest roentgenogram.

6 Explain the significance of massive hemoptysis

Massive hemoptysis is generally due to hemorrhaging from the bronchial artery (systemic pressure) circulation as opposed to the low-pressure pulmonary artery circuit and therefore is more capable of generating high-volume, life-threatening hemorrhage. Mortality from untreated massive hemoptysis in some studies is 75% to 100%.

7 List the tests that should be included in a routine evaluation of patients with hemoptysis

History, physical examination, complete blood cell counts including platelet count, coagulation studies, urinalysis, oxygenation by either pulse oximetry or arterial blood gas analysis, chest roentgenogram, and electrocardiogram.

8 What is the initial approach to the evaluation of a patient with hemoptysis in the intensive care unit?

Evaluation should begin with the routine tests previously described. After the patient has been hemodynamically stabilized, the site, etiology, and extent of bleeding should be determined. Identifying the site of bleeding requires visualization of the airways of both the upper and lower respiratory tract and examination of the chest roentgenogram. Pernasal fiberoptic bronchoscopy allows examination of the nasopharynx, larynx, and major airways and may reveal whether hemorrhaging is focal or diffuse. The presence of an endotracheal tube may compromise this examination. In this instance, upper airway bleeding may be detected by aspirating the trachea free of blood with a bronchoscope while the endotracheal cuff is expanded and then observing fresh blood flow down from above the cuff when it is decompressed. Rigid bronchoscopy may be required if hemorrhaging is massive, such that blood cannot be adequately removed with a flexible bronchoscope.

9 How does the chest roentgenogram assist in the evaluation of hemoptysis?

Examination of the chest roentgenogram often gives clues to both the site and etiology of hemoptysis. The presence of an infiltrate suggests the existence of a pulmonary parenchymal process. However, occasionally an infiltrate may occur after aspiration of blood coming from an airway source. Similarly, the presence of diffuse infiltrates suggests diffuse parenchymal disease, although this roentgenographic pattern may also occur with localized bleeding associated with severe coughing, which disperses blood throughout the lungs.

10 Do all patients with hemoptysis require bronchoscopy?