INTRODUCTION — Hemoptysis is the expectoration of blood or the presence of blood in the sputum. Young children usually swallow their sputum; as a result, hemoptysis is rare in children unless the bleeding is substantial [1].

DEFINITIONS — Hemoptysis refers to expectoration of blood originating from the lower respiratory tract. Blood from the upper respiratory tract, nasopharynx, and upper gastrointestinal tract can be expectorated and can mimic true hemoptysis. (See 'Mimics of hemoptysis' below.)

There is no consensus for quantifying the degree of hemoptysis. Previously, the volume of blood was used to indicate the severity of the hemorrhage and the risk for mortality [2]. In adults, a common threshold for defining massive hemoptysis is expectoration of ≥500 mL over a 24-hour period or bleeding at a rate of ≥100 mL/hour. In patients with cystic fibrosis (CF), a consensus panel classified hemoptysis as follows [3]:

●Scant – Less than 5 mL

●Mild to moderate – 6 to 240 mL

●Massive – More than 240 mL

However, such estimates are often imprecise and these categories do not account for the size of the patient. Moreover, an estimate of the volume of bleeding does not consistently predict the cause or outcome of bleeding in CF or other diseases. Thus, management depends on individual patient characteristics and clinical judgment, in addition to the volume of blood [2,4].

PATHOGENESIS — The lung contains two separate blood supplies:

●The pulmonary arterial circulation is a high-volume, low-pressure system, in which maximal pulmonary artery pressure normally does not exceed 40 mmHg [5]. Its branches accompany the bronchi down to the level of the terminal bronchioles. Ultimately, pulmonary vessels branch to supply the capillary bed in the walls of the alveoli, and then blood returns to the left atrium via the pulmonary veins.

●The bronchial circulation carries a much smaller volume of oxygenated blood, an estimated 1 percent of the cardiac output in a normal individual at rest, but does so at systemic pressures [6]. Usually, the patient has three recognizable bronchial arteries: two that supply the left lung and one that supplies the right, although 20 to 30 percent of individuals have two vessels on each side [7]. These arteries typically originate from the aorta or the intercostal arteries and perfuse conducting airways approximately to the level of the terminal bronchioles. More distally, the airway structures are nourished by the pulmonary artery circulation.

Bleeding can arise from either system. Bleeding usually is slower or more insidious when it arises from the pulmonary circulation (eg, in the presence of left-sided cardiac disease) because of the lower pressure. Bleeding is more likely to be substantial when it arises from the bronchial circulation because of the higher hydrostatic pressures promoting more vigorous hemorrhage.

ETIOLOGY — The causes of hemoptysis in children are outlined in the table (table 1) [8-11]. In children, respiratory infection, aspirated foreign bodies, and bronchiectasis are the most common etiologies, and among those with bronchiectasis, most have cystic fibrosis (CF) [12].

Airway diseases

Bronchiectasis — In patients with CF, chronic airway infection and inflammation damages the airway, stimulates neovascularization, and promotes growth of dilated and fragile bronchial arteries. These vessels lie close to the inflamed mucosal surface, increasing the risk of bleeding with cough or increased infection. This mechanism probably applies to non-CF bronchiectasis as well, though this has not been evaluated as rigorously. (See "Clinical manifestations and diagnosis of bronchiectasis in adults" and "Causes of bronchiectasis in children", section on 'Pathophysiology'.)

CF-associated bronchiectasis is a common cause of hemoptysis in children and adolescents. In a series of 228 patients admitted to a tertiary center with hemoptysis, 65 percent had CF [13]. Children and young adults with CF frequently experience small-volume hemoptysis with blood-streaked sputum, particularly during pulmonary exacerbations. Over time, up to 60 percent of patients older than 18 years of age with CF have blood-streaked sputum in intermittent episodes and 4.1 percent will suffer massive hemoptysis during their lifetime [3]. The risk for hemoptysis may decrease in the future with the advent of highly effective modulator therapies for CF [14]. In this population, coagulopathy secondary to vitamin K deficiency caused by fat malabsorption may exacerbate hemoptysis. In the CF patient, esophageal varices due to hepatic cirrhosis are also important causes of bleeding, which can mimic hemoptysis. Patients with bronchiectasis attributable to causes other than CF have an incidence of hemoptysis of approximately 10 percent. (See "Cystic fibrosis: Overview of the treatment of lung disease", section on 'Hemoptysis' and "Clinical manifestations and evaluation of bronchiectasis in children" and "Causes of bronchiectasis in children".)

Foreign body aspiration — Foreign body aspiration is a common occurrence in children, especially in those under three years of age. In a substantial majority of cases, the aspiration is not initially recognized within the first 24 hours of the event and the child may present days or weeks after the aspiration event with wheezing (usually monophonic and perhaps unilateral), chronic cough, pneumonia, or hemoptysis [15]. A history of choking is highly suggestive of foreign body aspiration, but the event may not be recalled at the time of presentation. (See "Airway foreign bodies in children".)

Airway trauma — In children with an acute respiratory infection, forceful cough can cause mechanical trauma to the airway and result in minor hemoptysis, characterized by blood-streaked sputum. This type of hemoptysis is usually benign and self-limited.

In children with endotracheal or tracheostomy tubes, suctioning beyond the tracheal opening of the tube can lead to mucosal injury of central airways, resulting in bloody sputum. In approximately 10 percent of such children, the bleeding is more than scant; bronchoscopy findings in such cases include mucosal abrasions or granulation tissue. Use of humidification, soft suction catheters, and suction to a measured length may help prevent bleeding or allow the injured mucosa to heal. Massive hemoptysis can occur in the rare instance of an airway tube eroding into a large vessel in the mediastinum or tracheal wall. The risk of erosion is greatly increased with the use of cuffed endotracheal or tracheostomy tubes.

In patients undergoing transbronchial biopsy, bleeding occurs in between 0.26 and 5.0 percent of cases and seldom is massive, based on studies in adults [2].

Pulmonary parenchymal diseases — Causes of bleeding originating from the pulmonary parenchyma fall into several major categories:

●Infection – Infection is the most common cause of hemoptysis in children without underlying pulmonary, cardiac, hematologic, or neoplastic disease. Hemoptysis can be caused by any pneumonia or lung abscess but is especially associated with tuberculosis or aspergilloma. Acute infection with endemic mycoses can produce massive hemoptysis in otherwise healthy children [16]. Influenza virus, including H1N1 influenza A, may present with significant bleeding [17-19]. Infections with relatively common community-acquired organisms such as Staphylococcus, Streptococcus, Klebsiella, and Pseudomonas can also cause hemoptysis, particularly if associated with necrotizing pneumonia [20,21]. (See "Clinical manifestations and diagnosis of chronic pulmonary aspergillosis".)

●Chest trauma – Chest trauma can cause hemoptysis because of a lung contusion or airway disruption.

●Coagulopathy – Any coagulopathy can predispose to hemoptysis, such as von Willebrand disease [22] or thrombocytopenia or in patients treated with anticoagulants. (See "Approach to the child with bleeding symptoms".)

●Pulmonary capillaritis – This is characterized by neutrophilic invasion and fibrinoid necrosis of the alveolar capillary walls. It may be isolated or part of a systemic vasculitis such as microscopic polyangiitis, granulomatosis with polyangiitis, anti-glomerular basement membrane disease (Goodpasture), systemic lupus erythematosus, immunoglobulin A vasculitis (Henoch-Schönlein purpura) [23], immunoglobulin A nephropathy, and antiphospholipid antibody syndrome. Capillaritis is also associated with certain drugs, including phenytoin, retinoic acid, and propylthiouracil. Pulmonary capillaritis is probably an underrecognized cause of diffuse alveolar hemorrhage in children [24,25]; lung biopsy is required for diagnosis. (See "Childhood-onset systemic lupus erythematosus (SLE): Clinical manifestations and diagnosis", section on 'Pulmonary' and "Granulomatosis with polyangiitis and microscopic polyangiitis: Clinical manifestations and diagnosis" and "The diffuse alveolar hemorrhage syndromes".)

●Idiopathic pulmonary hemosiderosis – This is a rare disease found primarily in children. It typically presents with recurrent dyspnea, cough, and anemia. Hemoptysis usually develops later but occasionally is a presenting symptom. It is characterized by hemosiderin-laden macrophages in bronchoalveolar lavage fluid without evidence of capillaritis or other cause of bleeding on lung biopsy [26]. (See "Idiopathic pulmonary hemosiderosis".)

●Acute idiopathic pulmonary hemorrhage of infancy (AIPHI) – This disorder is defined as an onset of pulmonary hemorrhage in a previously healthy infant less than one year of age, in whom no other causes for bleeding can be found [27]. Affected infants present with hemoptysis or blood in the nose or upper airway with no evidence of upper respiratory or gastrointestinal bleeding [28]. Initial reports from a cluster in Cleveland suggested a possible association between AIPHI and exposure to Stachybotrys chartarum (also known as Stachybotrys atra) toxin, a black mold found in damp ceilings and basements [29,30]. However, subsequent analyses have disputed the proposed association [27,31,32]. In some reported cases, the infants required mechanical ventilation but recovered completely [33]. A separate report suggests that von Willebrand disease caused or contributed to pulmonary hemorrhage in several cases that were initially diagnosed as AIPHI [22].

Among infants presenting with pulmonary hemorrhage, only a few will ultimately be diagnosed with AIPHI. In a case series of 157 infants presenting with acute pulmonary hemorrhage, an underlying cause could be identified in the vast majority after a thorough evaluation [34]. The most common causes were congenital heart disease (CHD) or prematurity (each approximately 30 percent) and congenital or acquired lung disorders or coagulopathies (each approximately 15 percent); AIPHI was identified in less than 1 percent.

●Miscellaneous – Miscellaneous causes of diffuse alveolar hemorrhage include hematopoietic stem cell transplant (presenting with hemoptysis during the first months after transplant), pulmonary veno-occlusive disease, and catamenial hemoptysis (recurrent hemoptysis that coincides with menses due to intrathoracic endometriosis). An association between celiac disease and pulmonary hemosiderosis has been termed "Lane-Hamilton syndrome" and appears to be rare [35,36].

In some cases, hemoptysis is related to a specific exposure, including medications (amiodarone, propylthiouracil, or penicillamine), or inhalation (nitrogen dioxide, pesticides, marijuana, vaping products, or cocaine). Several case reports describe hemoptysis due to inhalation of nitrogen dioxide in ice arenas with malfunctioning ice resurfacing and ventilation equipment [37,38]. (See "Etiology of hemoptysis in adults", section on 'Miscellaneous'.)

Pulmonary vascular disorders — Although this category overlaps with pulmonary parenchymal disease, the disorders mentioned below are those in which the primary pathology is intrinsic to the pulmonary vasculature or affects the pressure within these vessels.

●Pulmonary embolism – Pulmonary embolism may present with dyspnea, pleuritic pain, cough, and/or hemoptysis. This is rare in children younger than 15 years of age (incidence of 0.2 cases per 100,000 children/year) [39,40].

●Arteriovenous malformations – Hemoptysis may be a consequence of pulmonary arteriovenous malformations, either with or without underlying hereditary hemorrhagic telangiectasia (also known as Osler-Weber-Rendu syndrome). In a small series of infants with hemoptysis, aortopulmonary anastomoses were identified during cardiac catheterization and embolization of these abnormal anastomoses stopped the hemoptysis [41]. (See "Pulmonary arteriovenous malformations: Epidemiology, etiology, and pathology in adults" and "Clinical manifestations and diagnosis of hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome)".)

●Iatrogenic – Rarely, an indwelling Swan-Ganz catheter has perforated the pulmonary artery, leading to massive bleeding and death [42]. This complication is rare because Swan-Ganz catheters are now used infrequently.

●CHD – Hemoptysis is a known complication in patients with CHD. This symptom may account for up to 4.5 percent of cases of CHD presenting to the emergency department [43]. In a report from a pediatric tertiary care center, CHD was responsible for 25 percent of cases of hemoptysis [13]. Underlying defects that lead to hemoptysis include pulmonary venous obstructive disease, pulmonary hypertension (specifically, postcapillary hypertension), and left-sided cardiac obstructive lesions such as mitral stenosis and left ventricular diastolic dysfunction. Other cardiac-related causes of hemoptysis include congestive heart failure with pulmonary edema and high-altitude pulmonary edema, which may present with pink, frothy sputum. (See "High-altitude pulmonary edema".)

Hemoptysis associated with CHD has become less common with the evolution of early corrective cardiac surgery. However, there are several case reports of children presenting with massive hemoptysis many years after undergoing a Fontan procedure for hypoplastic left heart syndrome or tricuspid valve atresia; the hemorrhage is from collateral neovascularization [44-47].

●Pulmonary artery hypertension – Hemoptysis is uncommonly seen in patients with pulmonary hypertension and is a sign of advanced, life-threatening disease. It may be minor, episodic, or massive [48].

MIMICS OF HEMOPTYSIS — Hemoptysis specifically refers to expectoration of blood originating from the lower respiratory tract. Bleeding from the upper respiratory tract, nasopharynx, or upper gastrointestinal tract can mimic true hemoptysis. As an example, cystic fibrosis (CF) predisposes to both hemoptysis (due to bronchiectasis) and bleeding from esophageal varices (due to cirrhosis), and the bleeding source is not always apparent (see 'Bronchiectasis' above). The history and physical examination should investigate these possible sources of bleeding. In some patients, investigations such as gastrointestinal endoscopy or nasopharyngeal fiberoptic endoscopy may be needed to exclude gastrointestinal or nasopharyngeal sources of bleeding. In such cases, it may be prudent to arrange for fiberoptic bronchoscopy, esophagogastroduodenoscopy, and nasopharyngoscopy under a single anesthetic.

Factitious hemoptysis, where children have inflicted injuries mimicking pulmonary bleeding, has been described [49]. Munchausen syndrome (or Munchausen syndrome by proxy) should be considered in a patient who presents with hemoptysis, unusual symptoms, and a negative evaluation [50]. (See "Factitious disorder imposed on self (Munchausen syndrome)" and "Medical child abuse (Munchausen syndrome by proxy)".)

DIAGNOSTIC APPROACH

Assessment of sputum — The quantity and appearance of the bloody sputum should be assessed by direct observation, if possible, as well as thorough questioning the patient and caretakers. The quantity of blood should be categorized as scant, mild or moderate, or massive (see 'Definitions' above). These efforts also should attempt to localize the bleeding source to either the gastrointestinal tract or the upper or lower respiratory tract, based on the following characteristics:

●Blood from a pulmonary source (true hemoptysis) usually is bright red or rust-colored, and it can be frothy and mixed with sputum. The pH usually is alkaline. Symptoms include coughing or a gurgling noise perceived by the patient. Older children may report discomfort in one hemithorax that may help localize the bleeding site. Frothy sputum suggests an alveolar source of bleeding.

●In contrast, blood from a gastric source (hematemesis) usually is crimson or brown with a coffee-ground appearance and may contain food particles. The pH is acidic, and nausea or retching may precede the episode.

These characteristics are helpful, but they are not reliable indicators of the source of the bleeding. If gastrointestinal bleeding is suspected, this possibility should be further explored through an upper gastrointestinal endoscopy. This includes patients with cystic fibrosis (CF) or other causes of liver disease, who are at risk for portal hypertension and bleeding from esophageal varices. In all patients, the possibility of nasopharyngeal bleeding should be explored by a careful inspection during the physical examination, with nasopharyngeal fiberoptic endoscopy if needed. (See 'Mimics of hemoptysis' above.)

History and associated findings — Once the patient is stable, a thorough history should be sought. Findings that provide clues to the cause of hemoptysis include:

●Mucopurulent sputum that is streaked with blood often suggests tracheobronchitis or bronchiectasis.

●Fever or chills accompanying blood-streaked purulent sputum suggest pneumonia, whereas putrid-smelling sputum raises the possibility of anaerobic lung abscess.

●A history of a choking episode suggests the possibility of a tracheal foreign body, even if it occurred several days or weeks prior to the hemoptysis. (See 'Foreign body aspiration' above.)

●Exposures that can cause hemoptysis include illicit drugs (particularly cocaine smoking, vaping, or other inhalational drugs), medications that can be associated with alveolar hemorrhage (eg, amiodarone, propylthiouracil, or penicillamine), or medications that can impair platelet function or produce thrombocytopenia. (See "Cocaine: Acute intoxication", section on 'Crack lung and other pulmonary complications' and "Drug-induced immune thrombocytopenia".)

●Hematuria suggests a pulmonary-renal syndrome. (See "The diffuse alveolar hemorrhage syndromes".)

●A history of recent exposure to fumes from malfunctioning ice resurfacing and ventilation equipment in an ice arena raises the possibility of nitrogen dioxide inhalation. (See "Etiology of hemoptysis in adults", section on 'Miscellaneous'.)

●The review of systems should explore symptoms suggestive of underlying diseases or exposures, including weight loss, history of bleeding from other sites (eg, easy bruising or menorrhagia), trauma, chronic pulmonary or cardiac disease, systemic symptoms of vasculitis syndromes, and recent travel.

Physical examination — Findings on the physical examination that provide clues to the cause of hemoptysis include:

●Bruises around the chest or neck (indicating trauma)

●Crepitus suggesting airway disruption

●Telangiectasia or hemangioma (suggesting arteriovenous malformations)

●Digital clubbing (suggesting chronic suppurative lung disease, pulmonary arteriovenous malformations, or congenital heart disease [CHD])

●Bleeding in the oral cavity or nasopharynx or missing teeth may be suggestive of foreign body aspiration

●Focally abnormal breath sounds may be seen in infectious causes, foreign body aspiration, or localized airway or parenchymal bleeding

Imaging — Chest radiographs in at least two views should be obtained. Typical radiographic findings include parenchymal and alveolar opacities that may be diffuse throughout both lungs (image 1) or may identify a focal site of the bleeding. This finding does not exclude aspiration of blood from nonpulmonary sources. Other features suggesting a specific etiology of bleeding include cavitations (suggesting tuberculosis, fungal infection, or granulomatosis with polyangiitis), radiopaque foreign bodies or volume loss suggestive of endobronchial obstruction, or bronchiectasis. However, up to one-third of children with hemoptysis will have normal radiographs [51,52].

For patients with moderate or severe hemoptysis that is not explained, we suggest additional imaging with computed tomography (CT) of the chest with contrast or multidetector CT angiography. If pulmonary embolism is suspected, the study should be optimized to visualize the vessels (CT angiography). CT angiography is the test of choice to visualize lung parenchyma; alveolar hemorrhage typically appears as "ground-glass" opacities in the perivascular areas (image 2). In some cases, the CT may help identify anatomic abnormalities of both airways and vessels. (See "Clinical presentation, evaluation, and diagnosis of the nonpregnant adult with suspected acute pulmonary embolism", section on 'Computed tomography pulmonary angiography'.)

Pulmonary arteriography should be considered if a high suspicion for vascular malformations exists despite a negative CT scan. In massive hemoptysis, bronchial arteriography may localize the area of bleeding and facilitate bronchial artery embolization (BAE) [53]. (See 'Bronchial artery embolization' below.)

Laboratory tests — The laboratory evaluation should be directed by the history and physical examination. For patients with hemoptysis that is more than mild (≥5 mL blood) and of unknown cause, consultation with a pediatric pulmonologist is recommended. Routine testing for such patients should include:

●A complete blood count and coagulation studies, including studies to exclude von Willebrand disease (plasma von Willebrand factor antigen, von Willebrand factor activity, and factor VIII activity) [22]. (See "Clinical presentation and diagnosis of von Willebrand disease".)

●Patients with moderate or more hemoptysis should have blood typed and cross-matched in case bleeding necessitates transfusion. The need for transfusion is uncommon unless the hemoptysis is massive.

●Sputum cultures for bacteria, fungus, virus, and acid-fast bacilli should be obtained, if possible.

●If diffuse alveolar hemorrhage leading to hemoptysis is suspected, the child should be evaluated for vasculitic diseases. Appropriate tests include serum creatinine and blood urea nitrogen, urinalysis, antinuclear antibodies (ANA panel), antineutrophil cytoplasmic antibodies, anti-glomerular basement membrane antibodies (anti-GBM), antiphospholipid antibodies, complement, erythrocyte sedimentation rate, and C-reactive protein. Fungal serologies also may be helpful. (See "Vasculitis in children: Evaluation overview".)

●If bronchiectasis is seen on imaging and is otherwise unexplained, we suggest diagnostic tests for CF. (See "Causes of bronchiectasis in children".)

Diagnostic bronchoscopy — For most patients with hemoptysis that is more than mild (≥5 mL blood) and otherwise unexplained, we suggest proceeding to diagnostic bronchoscopy once the bleeding is controlled (except for CF patients with massive hemoptysis, for whom BAE is the next step). Flexible rather than rigid bronchoscopy usually is used for this purpose. Bronchoscopy permits direct inspection of the airways to identify the bleeding site and possible cause. The presence of blood in the bronchoalveolar lavage fluid confirms alveolar bleeding (picture 1). The fluid should be sent for cytology to evaluate for hemosiderin-laden macrophages. Hemosiderin-laden macrophages typically appear three days after the episode of bleeding and may persist for days or weeks; if present, they suggest that the bleeding is subacute or chronic, rather than acute [1,54,55]. Rigid bronchoscopy is the procedure of choice if a foreign body extraction is required or if profuse bleeding occurs. (See 'Bronchoscopy' below and "Airway foreign bodies in children".)

Lung biopsy — A lung biopsy should be considered in any child with imaging findings suggesting diffuse alveolar hemorrhage or with persistent unexplained hemoptysis. Such patients also should have a full serologic evaluation for vasculitis, as outlined above. However, a lung biopsy is appropriate in patients with a strong clinical suspicion of immune-mediated disease even if serologic testing is negative because there are reported cases of immune-mediated lung disease with negative serology [24,56].

INITIAL MANAGEMENT OF MASSIVE HEMOPTYSIS — For patients with large-volume or massive hemoptysis, the first steps are to stabilize the patient and prevent further bleeding, as outlined below (algorithm 1). In these patients, evaluation for the cause of the hemoptysis occurs simultaneously or as a second step after stabilization. (See 'Diagnostic approach' above.)

General measures — Patients with large-volume or massive hemoptysis require a stable airway with intubation and mechanical ventilation, circulatory support, and replacement of blood products. Mechanical ventilation with high positive end-expiratory pressure (PEEP) may improve oxygenation and tamponade the site of hemorrhage. Selective intubation to the unaffected lung may help decrease the risk of asphyxiation and assist in ventilation. When the site of bleeding is unknown, double-lumen tubes should be used, if available for the child's size [57]. For the cystic fibrosis (CF) patient with massive hemoptysis, bilevel positive airway pressure (BiPAP) should be discontinued due to the risk of further aspiration of blood and the potential need for a more stable airway [3]. For this reason, BiPAP is also not recommended for non-CF hemoptysis.

Cough should be minimized by opiates in order to prevent worsening of hemoptysis. If the hemithorax in which the bleeding originates can be identified (either by chest radiograph or physical findings), the patient should lie with the bleeding side down in order to prevent blood from filling the unaffected lung. Chest physiotherapy and medications that may affect clotting should be stopped, including nonsteroidal antiinflammatory drugs [3].

Bronchoscopy — If bleeding does not stop with these measures, bronchoscopy usually is the next step to evaluate and control active bleeding. For patients with CF and massive hemoptysis who are clinically unstable, a consensus panel suggests proceeding directly to bronchial artery embolization (BAE) rather than performing bronchoscopy for evaluative purposes prior to BAE [3,58]. This does not preclude performing bronchoscopy for therapeutic purposes in CF patients if the clinicians judge that this would be valuable for the individual patient. Similarly, proceeding directly to BAE is appropriate for some patients without CF, if the source of the bleeding is known or localized by radiography [59]. (See 'Bronchial artery embolization' below.)

No clear consensus exists as to whether rigid or flexible bronchoscopy (also called fiberoptic bronchoscopy) is preferable. The information gained from these techniques is complementary, and the procedures may be performed sequentially under the same sedation.

Rigid bronchoscopy is preferred by some clinicians in cases of ongoing profuse bleeding because it allows airway control and more rapid suctioning of large volumes of clots and debris. The larger lumen also permits interventions to provide tamponade. However, this technique must be performed using general anesthesia and, generally, it is performed by a surgeon in an operating room, so the patient may need to be moved. The visual range of rigid bronchoscopy is limited to the major bronchi.

Flexible bronchoscopy also can be used to control bleeding. It is less useful than rigid bronchoscopy for managing profuse bleeding, but it can be performed at the bedside and permits visualization of the distal airways because of the smaller diameter of the flexible bronchoscope.

If the bleeding site is identified during bronchoscopy, a solution of cold saline, topical epinephrine, or both can be used to achieve hemostasis [60,61]. If this fails, a mixture of fibrinogen and thrombin has been used [62]. Other procedures that have been described include bronchoscopy with carbon dioxide or Nd-YAG laser, and balloon tamponade of a lobe or main bronchus using a balloon-tipped catheter (Fogarty catheter) placed during bronchoscopy [2,63]. (See "Evaluation and management of life-threatening hemoptysis".)

Bronchial artery embolization — BAE by bronchial angiography should be considered in cases of persistent bleeding and is widely used in patients with CF and hemoptysis [3,33]. The success of BAE is enhanced by coupling it with multidetector computed tomography (CT) to precisely locate the bleeding vessels [64]. Once the bleeding vessels are identified, the appropriate vessels are cannulated and then injected with gelatin sponge, polyvinyl alcohol, bucrylate pellets, or tris-acryl gelatin microspheres. Outcome is favorable in approximately 80 percent of cases, but bleeding may recur in a significant percentage (eg, in approximately 20 percent of patients with CF within one year) [65-67]. Up to 40 percent of these recurrences may require a second embolization procedure. Rare complications include transverse myelitis or bowel necrosis if spinal arteries or superior mesenteric artery are inadvertently embolized. In addition, fever, dysphagia, and back and chest pain can occur after the procedure. The main contraindication to embolization is the presence of spinal arteries arising directly from the bronchial vessels.

Other measures

●Tranexamic acid (TXA), an antifibrinolytic medication used previously to control bleeding among hemophiliacs, has been evaluated in children and adults with CF, as well as for hemoptysis that did not respond to embolization [67-72]. TXA has been administered intravenously [73], inhaled [71], and orally [72] for adult patients with non-massive hemoptysis. Based on this limited data from adult studies, all of these routes of administration seem to have some effectiveness and have been well tolerated. Two of the adult studies [71,73] included patients with malignancy, bronchiectasis, and tuberculosis as the cause of the patient's hemoptysis. The third study focused on adults with CF who were experiencing multiple recurrences of hemoptysis, and their protocol included oral epsilon-aminocaproic acid as well as oral TXA [72]. Administration of TXA by any of these routes to children for hemoptysis is an off-label use.

●The use of a beta adrenergic blocker (atenolol) was evaluated in a small observational study in CF patients with refractory hemoptysis and appeared to have some benefit [74].

●Surgical resection of the bleeding site (lobectomy or pneumonectomy) is a last resort for control of ongoing focal hemoptysis [3,75]. It is indicated only in patients who have massive bleeding or intractable hemorrhage, after all other measures to control bleeding have failed. Candidates for surgical resection ideally should have an adequate respiratory reserve (forced expiratory volume in one second [FEV₁] >40 percent predicted) in order to avoid extreme pulmonary disability postoperatively. Unfortunately, patients with CF who have significantly advanced disease and limited pulmonary reserve may tolerate this procedure poorly.

●Extracorporeal life support has also been described in the management of life-threatening hemoptysis [45]. In patients with advanced pulmonary arterial hypertension and hemoptysis, urgent evaluation and listing for lung transplantation may be in order. These and other techniques for controlling hemoptysis that are used in adults are discussed separately. (See "Evaluation and management of life-threatening hemoptysis".)

MANAGEMENT OF MILD OR MODERATE HEMOPTYSIS — Management and the diagnostic approach in patients with mild or moderate hemoptysis depends on the clinical presentation of the patient, presence or absence of a known underlying disease (eg, cystic fibrosis [CF]), and progression of symptoms (algorithm 1).

In most children and adolescents without a chronic underlying disease, hemoptysis is mild (streaks or a few mL of blood). For such patients, a focused history, physical examination, and chest radiograph usually are sufficient to determine whether the hemoptysis is consistent with a benign cause (eg, bronchitis with forceful coughing or trauma from deep suctioning). In such cases, the hemoptysis tends to resolve spontaneously and is unlikely to recur. No further intervention is necessary, other than observation for recurrence and appearance of other symptoms. (See 'Airway trauma' above.)

Particular attention should be paid to clinical characteristics that suggest the possibility of foreign body aspiration, especially in young children or those with swallowing dysfunction. These include a history of choking (days to weeks prior to hemoptysis, even if transient) and new respiratory symptoms such as wheezing. Children with foreign body aspiration may or may not have an abnormal chest radiograph and fever. If foreign body aspiration is suspected, bronchoscopy should be performed for diagnosis and removal. (See 'Foreign body aspiration' above.)

For patients with CF and mild or moderate hemoptysis (≥5 mL blood), consensus guidelines specifically recommend stopping nonsteroidal antiinflammatory drugs and treating with systemic antibiotics (table 2) [3]. The guidelines also suggest continuing inhaled antibiotics and bronchodilators in most cases of mild or moderate hemoptysis, but with some reservations, and suspending inhaled airway clearance therapies. At our institution, we often administer supplemental vitamin K just in case the bleeding is related to vitamin K deficiency. (See 'Bronchiectasis' above and "Cystic fibrosis: Overview of the treatment of lung disease".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hemoptysis".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Coughing up blood (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Hemoptysis refers to expectoration of blood originating from the lower respiratory tract. Blood from the upper respiratory tract, nasopharynx, and upper gastrointestinal tract can be expectorated and can mimic true hemoptysis. A bright red color, alkaline pH, and, sometimes, thoracic pain can help to distinguish hemoptysis from blood originating in the gastrointestinal tract. (See 'Mimics of hemoptysis' above and 'Assessment of sputum' above.)

●The most common causes of hemoptysis in children are respiratory infection, aspirated foreign bodies, and bronchiectasis; bronchiectasis is most common in children with cystic fibrosis (CF). A variety of other processes also can cause hemoptysis (table 1). (See 'Etiology' above.)

●Foreign body aspiration is common in children, especially in those under three years of age. In a substantial proportion of cases, the aspiration is not initially recognized and the child may present days or weeks after the aspiration event with wheezing, chronic cough, and/or hemoptysis. (See 'Foreign body aspiration' above and "Airway foreign bodies in children".)

●A chest radiograph and, in some cases, computed tomography (CT) may help to determine the location of the bleeding and often provide clues to the type of lung disease. Up to one-third of children with hemoptysis will have normal radiographs. (See 'Imaging' above.)

●Emergency management of a patient with massive hemoptysis who is hemodynamically unstable includes intubation and mechanical ventilation, circulatory support, and replacement of blood products (algorithm 1). Mechanical ventilation with high positive end-expiratory pressure (PEEP) may improve oxygenation and help to tamponade the site of hemorrhage. Interventions to stop the bleeding include bronchoscopy with hemostasis interventions and/or bronchial artery embolization (BAE). Patients with CF and massive hemoptysis should proceed directly to BAE rather than attempting bronchoscopy. (See 'Initial management of massive hemoptysis' above.)

●For patients with hemoptysis that is more than mild (≥5 mL blood) and of unknown cause, laboratory testing should include a complete blood count and coagulation studies, including studies to exclude von Willebrand disease. Additional testing that may be helpful in determining the cause of hemoptysis in some cases includes evaluation for systemic inflammatory or vasculitis conditions and sputum culture for bacteria, fungus, virus and acid-fast bacilli, when available. (See 'Laboratory tests' above.)

●Flexible bronchoscopy can be helpful in some patients with hemoptysis to identify the bleeding site. Rigid bronchoscopy is the procedure of choice if a foreign body extraction is required or if profuse bleeding occurs. (See 'Diagnostic bronchoscopy' above and 'Bronchoscopy' above.)

●Lung biopsy may be required if the cause of hemoptysis remains unknown after an extensive evaluation, particularly if the radiographic findings are consistent with diffuse alveolar hemorrhage. (See 'Imaging' above and 'Lung biopsy' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Diana R Quintero, MD, and Leland L Fan, MD, who contributed to an earlier version of this topic review.