Evaluation and management of life-threatening hemoptysis

INTRODUCTION — The expectoration of blood that endangers life or the expectoration of large amounts of blood is associated with high morbidity and mortality. Prompt recognition and therapy are critical to successful management. The management steps discussed in this topic assume that pseudohemoptysis (ie, bleeding from the upper respiratory tract and gastrointestinal tract) has been sufficiently ruled out.

The definition, initial management, diagnostic evaluation, and definitive treatment of life-threatening hemoptysis are reviewed here. The etiology of hemoptysis and management of non-life-threatening hemoptysis are discussed separately. (See "Etiology of hemoptysis in adults".)

DEFINITION — We generally prefer to use the term “life-threatening hemoptysis” when hemoptysis results in a life-threatening event including significant airway obstruction, significant abnormal gas exchange, or hemodynamic instability [1]. In our clinical practice, we also consider hemoptysis to be life-threatening when there has been approximately 150 mL of blood expectorated in a 24-hour period (easily quantifiable by patients as roughly a half cup of blood in 24 hours) or bleeding at a rate ≥100 mL/hour [1].

The term life-threatening hemoptysis (formerly massive hemoptysis) was used in the past to describe the expectoration of a large amount of blood and/or a rapid rate of bleeding [1-5]. However, the precise thresholds that constitute life-threatening hemoptysis are controversial. Criteria based solely on the volume of blood cannot be used precisely since quantifying the amount of blood that a patient has expectorated is challenging and small amounts in patients with underlying cardiorespiratory disease may be enough to endanger life, particularly if thrombus obstructs a major airway or there is very little residual functional lung tissue.

EPIDEMIOLOGY — While hemoptysis is common, life-threatening events due to hemoptysis are uncommon. Studies have been fraught with inaccurate estimates due to varying definitions of life-threatening hemoptysis as well as heterogeneity of the studied populations (and consequent etiologies of hemoptysis). Older data suggest that between 5 and 15 percent of patients with hemoptysis present with a life-threatening event, but these reports likely overestimate the true rate [2,6,7]. Large series that describe the etiology of hemoptysis are lacking. However, one observational report from five Italian hospitals reported that approximately 30 percent of patients had moderate hemoptysis (20 to 500 mL) and slightly more than 2 percent had severe hemoptysis (>500 mL) [8].

CAUSES OF LIFE-THREATENING HEMOPTYSIS — The most common etiologies for life-threatening hemoptysis are bronchiectasis, bronchogenic cancer, tuberculosis, and fungal infections. However, life-threatening hemoptysis can result from any etiology associated with non-life-threatening hemoptysis (table 1 and table 2), the details of which are discussed separately. (See "Etiology of hemoptysis in adults", section on 'Causes of life-threatening hemoptysis'.)

It has been suggested that in 90 percent of patients with life-threatening hemoptysis, bleeding arises from the high-pressure bronchial circulation. Approximately 5 percent of bleeding events arise from the aorta or non-bronchial systemic circulation (eg, intercostal, coronary, thoracic, axillary, subclavian, and upper and lower inferior phrenic arteries) and the remaining 5 percent arise from the low-pressure pulmonary artery system [9,10]. (See "Etiology of hemoptysis in adults", section on 'Bronchial versus pulmonary arterial origins of hemoptysis'.)

INITIAL LIFE-SAVING AND SUPPORTIVE MEASURES — While efforts are ongoing to obtain useful clinical information from a brief history (table 3), examination (table 4), laboratory tests (table 5), and imaging, the clinician should ensure adequate oxygenation and ventilation, position the patient (lateral decubitus with suspected bleeding side down), ensure hemodynamic stability, obtain IV access, and perform initial measures to control the bleeding (eg, treat any bleeding diathesis). In general, patients should be admitted to the intensive care unit for close monitoring when transfer is considered safe; early consultation of subspecialist services is prudent including pulmonary or interventional pulmonary, interventional radiology, thoracic surgery, and, if appropriate, radiation oncology and/or medical oncology (table 6).

Intubation and ventilation — In most patients with life-threatening hemoptysis, intubation with a large bore endotracheal tube (ETT; size 8 or greater, if possible) is prudent. The purpose of the large lumen size is to facilitate blood and thrombus extraction as well as interventional and diagnostic bronchoscopy; however, intubation should not be delayed if passing a large bore ETT is not immediately feasible. Patients with life-threatening hemoptysis are not typically candidates for noninvasive ventilation (NIV), especially with a full-face mask since the risk of aspirating blood is high. If patients refuse or do not need ventilation, then low or high flow nasal oxygen or NIV via a nasal mask or prongs are options. Nasotracheal intubation is discouraged since the lumen of the endotracheal tube is often too small for therapeutic bronchoscopic intervention. (See "Heated and humidified high-flow nasal oxygen in adults: Practical considerations and potential applications" and "Continuous oxygen delivery systems for the acute care of infants, children, and adults".)

In most patients, both lungs are ventilated with the standard placement of the ETT at 3 to 5 cm above the carina. For patients who continue to bleed, single lung ventilation or double lumen ventilation are alternatives, the details of which are discussed below. (See 'Additional airway protection options' below.)

Patients with life-threatening hemoptysis may be hypoxemic, hypercapnic, or both. There are no unique ventilatory strategies for such patients. In our clinical practice, we generally deliver volume-targeted breaths using assist control ventilation. It should be remembered, however, that if only one lung is being ventilated, tidal volumes should be reduced accordingly (ie, by half). Alternative modes of mechanical ventilation are also acceptable. An approach to establishing initial ventilator settings in a critically ill patient is described separately. (See "Overview of initiating invasive mechanical ventilation in adults in the intensive care unit".)

Supportive care

Position the patient — Regardless of intubation status, patients should be immediately placed into a position where the suspected bleeding lung is in the dependent position. A patient whose right lung is bleeding should be placed in the right-side down decubitus position, whereas a patient whose left lung is bleeding should be placed in the left-side down decubitus position. The purpose of positioning is to protect the nonbleeding lung, since spillage of blood into the nonbleeding lung may impair gas exchange by blocking the airway with clot or filling the alveoli with blood. However, determining the side of bleeding may be challenging clinically and although some clues may exist (eg, known procedure or pathology on one side), physical examination findings alone (eg, auscultatory sounds) can be misleading since blood may spill into another site bleeding site from gravitational pooling.

Ensure hemodynamic stability — Patients with life-threatening hemoptysis are typically tachycardic and may become hypotensive. Such patients should be managed with volume resuscitation. Crystalloid intravenous fluids are generally administered first because they are readily available. However, in patients who are coagulopathic, anemic, and/or bleeding rapidly, blood products are an appropriate alternative. Patients with life-threatening hemoptysis may also have arrhythmias that are probably hypoxemia-related. Arrhythmias are best managed by optimizing gas exchange and then using antiarrhythmic therapy if they persist. The management of patients with hemorrhagic shock from significant bleeding (eg, thoracic trauma or from a ruptured aortic bronchial fistula) are discussed separately. (See "Initial management of moderate to severe hemorrhage in the adult trauma patient".)

Correct bleeding diathesis — Patients with life-threatening hemoptysis should have all known or suspected bleeding disorders rapidly reversed, if feasible. Those who are receiving an anticoagulant should receive fresh frozen plasma (eg, warfarin) and/or a reversal agent (eg, direct oral anticoagulants [DOACs]). Those who are thrombocytopenic (eg, <50 X 10³ platelets/microL) should receive a platelet transfusion. Patients who are uremic or taking an antiplatelet agent (eg, aspirin, clopidogrel) may also benefit from transfused platelets or desmopressin (vasopressin analog, also called DDAVP). Nonsteroidal anti-inflammatory agents should be stopped. Reversal agents for DOACs are discussed separately. (See "Management of bleeding in patients receiving direct oral anticoagulants" and "Use of blood products in the critically ill", section on 'Platelets'.)

Tranexamic acid (TA) is an antifibrinolytic agent. Data from case reports in critically ill patients and one small randomized trial in noncritically ill patients suggest that inhaled TA may have some benefit in patients with hemoptysis [11-16]. In one randomized trial of 47 patients with non-life-threatening hemoptysis, inhaled TA (500 mg/5 mL for up to five days) resulted in a reduction in hemoptysis volume, faster resolution of hemoptysis and shorter hospital stay when compared with patients who were treated with inhaled normal saline [11]. Whether TA has a similar benefit in patients with life-threatening hemoptysis is unknown since it has not been studied in that population. A case series of three critically ill patients with hemoptysis suggested similar results [15].

Others — All underlying disorders should be treated. Bronchodilators are not generally withheld in patients with hemoptysis, especially if the patient has severe bronchospasm.

INITIAL INVESTIGATIONS — While the order and timing of investigations should be individualized, the sequence often depends upon the relative stability of the patient as well as available services and expertise. In most cases, initial diagnostic efforts must occur simultaneously with ongoing efforts to stabilize the patient and control the bleeding. A brief history (table 3), physical examination (table 4), chest radiography, and routine laboratories (table 5) should be performed (table 6). These, together with bedside echocardiography, which is occasionally performed during resuscitation, typically provide clues to help determine the source of hemoptysis and/or predisposition for bleeding (eg, coagulopathy). Ideally, both bronchoscopy and chest computed tomography (CT) are performed within the first 12 to 24 hours and provide complementary information. Bronchoscopy has the advantage that it can be performed bedside in the unstable patient but requires expertise, which may take some time to obtain. In addition to providing useful diagnostic information (eg, identify the bleeding site or source or the bleeding side or lobe), bronchoscopy can also act as an acute management tool to control the bleeding (eg, guide balloon occlusion). In contrast, chest CT is more readily available and many emergency departments have their own CT suite for rapid imaging, but CT may require the patient to be relatively stable and may not be suitable for patients who have continued life-threatening hemoptysis despite initial resuscitation. However, the presence of blood primarily in one lung on chest CT does not guarantee that the identified lung is the main side responsible for bleeding. Bronchoscopy with observation of fresh bleeding after the airways have been cleared by saline lavage is the preferred test to localize the side or lobe of bleeding. (See 'Initial bronchoscopy' below and 'Chest computed tomography' below.)

The increased diagnostic yield of a combined modality approach for the diagnosis of lung cancer in patients with hemoptysis was illustrated by a study which found that lung cancer was diagnosed by chest CT alone with a sensitivity of 67 percent, bronchoscopy alone with a sensitivity of 42 percent, and chest CT plus bronchoscopy with a sensitivity of 93 percent [2].

Case reports have described using radionuclide scanning with tagged red blood cells to localize the bleeding site in patients with hemoptysis [17]. However, this requires a rapid rate of bleeding and can give false localization if blood pools in dependent regions. In addition, it requires transport out of the ICU which can be dangerous in a patient with significant bleeding. From a practical standpoint, tagged red blood cell scanning is not very useful.

Initial bronchoscopy — Early flexible bronchoscopy is the initial diagnostic procedure of choice in most patients with life-threatening hemoptysis. This is because it can be performed at the bedside and it is often successful at identifying the bleeding site (or at least which lung or lobe is the potential source), especially if it is performed while the patient is bleeding [9,17,18]. It can also be used as a therapeutic tool to prevent recurrence.

We perform bronchoscopy early in a patient's course (ie, first 12 to 24 hours). We believe that this approach provides clinicians with the maximal amount of information upon which to base future decisions. For example, it can provide guidance for subsequent angiographic and embolization procedures, should the patient re-bleed. In addition, this strategy may lead to earlier treatment or earlier initiation of additional diagnostic testing.

The patient should preferably be stable for bronchoscopy to be performed. However, the procedure can be performed in an unstable patient, if necessary.

Rigid bronchoscopy is typically only used when greater suction capacity and superior visualization is needed (eg, large volumes of blood causing asphyxiation). Rigid bronchoscopy may also be needed for a specific therapeutic intervention (eg, laser therapy, electrocautery, argon plasma coagulation). When rigid bronchoscopy is chosen, almost always, a flexible bronchoscope is inserted through the lumen of the rigid bronchoscope, thereby combining the more distal visualization of the airways offered by flexible bronchoscopy with the superior suction capabilities and the wider range of therapeutic options offered by rigid bronchoscopy. (See "Rigid bronchoscopy: Instrumentation" and "Rigid bronchoscopy: Intubation techniques".)

Blood and thrombus removal — Some patients have life-threatening symptoms because of thrombus in a central airway causing obstruction or in several airways causing respiratory distress and hypoxemia. Both situations necessitate aggressive suctioning and thrombus removal. Identification of thrombus in a specific location, however, does not provide confident assurance that the source of bleeding lies distally since blood may have moved from the original source to another site. For adherent clot that is difficult to remove bronchoscopically, a rigid bronchoscope or cryotherapy can be performed. Once any obstructing thrombus and blood have been removed, a thorough inspection of the airways should be undertaken (at this point or later) with a flexible bronchoscope to assess the location and source of bleeding. (See 'Intermittent or slowed hemoptysis' below.)

Localizing and identifying the source of bleeding — Localizing the bleeding site requires visualization of active bleeding from a specific lesion, orifice, lobe, or segment/sub-segment. This may range from obvious bleeding from an endobronchial tumor to mild oozing arising from a lung segment/subsegment (table 1). When active bleeding cannot be directly visualized, small volume lavage of multiple bronchial segments can sometimes help localize the bleeding site by identifying bronchi that contain fresh blood with ongoing washing. Once the bleeding site is localized, the area should be carefully inspected for a culprit lesion, such as a bronchogenic carcinoma or Dieulafoy lesion. Even if the bleeding lesion cannot be identified, there may be other clues regarding the cause of the bleeding. As an example, erythematous and edematous airways in the area of bleeding may indicate an infection. Specimens should be taken for microbiological and cytological testing. Identifying the cause is discussed below. (See 'Intermittent or slowed hemoptysis' below.)

Treating the bleeding — There are a variety of bronchoscopic techniques that may control pulmonary hemorrhage, although no controlled studies have demonstrated their comparative efficacy. They include iced saline lavage, topical medications (eg, epinephrine), balloon tamponade or bronchial blockade, and local thermal ablative therapies. While iced saline and topical medications can be administered during regular bronchoscopy, placement of bronchial blockers/balloons may require a more experienced bronchoscopist; interventionalist expertise is required for thermal ablative techniques.

The success of local measures varies with the source of bleeding and data to support one method over others are nonexistent. However, one study suggested a success rate of 17 percent when conservative measures are used (eg, iced saline and topical epinephrine); rates are likely higher when more aggressive interventions are used such as bronchial blockade and local ablation therapies.  

Choosing among the bronchoscopic options is at the discretion of the operator and depends upon expertise and experience of the bronchoscopist, as well as the location of the bleeding site. In some cases, the operator may incrementally try different techniques including iced saline first followed by topical vasoconstrictors and a bronchial blocker device. When the bleeding is distal (ie, coming from a segmental or subsegmental airway) the bronchoscopist may also try wedging the tip of the bronchoscope into the bleeding segment (usually with distal topical vasoconstrictor instillation) in an attempt to induce clot formation locally. This, however, would not be feasible for a more proximal site.  

Local bronchoscopic options include the following:

●Iced saline lavage – To perform iced saline lavage, approximately 1 L of saline (eg, twenty 50 mL syringes) should be cooled in ice while life-saving measures are being achieved and the bronchoscopy equipment is being set up. Once the saline has cooled, bronchoscopy is performed and the source of bleeding is localized. The bleeding source is then lavaged using 50 mL aliquots of cold saline. In one case series, the average volume of saline used was 500 mL per patient and one patient experienced bradycardia [19]. It is believed that iced saline lavage works by causing local vasoconstriction, thereby reducing blood flow and promoting hemostasis [17]. There are no controlled data showing benefit.

●Topical medications – A topical vasoconstrictive agent (usually epinephrine [1:20,000] or vasopressin) can be infused through a bronchoscope and directly onto the bleeding source to slow or stop the bleeding. Reports of using other agents such as topical coagulants (eg, thrombin, a fibrinogen-thrombin combination, or tranexamic acid) have also been reported [20-22]. These methods have not been compared in trials; however, our clinical experience suggests that topical epinephrine is as effective as or more effective than alternative topical medications and is also easily available. While published doses and concentrations differ, we typically start with small volumes of 3 to 5 mL of 1 mg/10 mL epinephrine and repeat as needed up to 20 mL. Topical vasoconstrictors can be associated with the development of tachycardia and hypertension. Bronchoscopic tranexamic acid is discussed separately. (See "Flexible bronchoscopy in adults: Preparation, procedural technique, and complications", section on 'Bleeding'.)

●Bronchial blockade devices and balloon tamponade – Bronchial blockade and balloon tamponade involve the placement of devices that have a balloon/cuff on the tip that can be inflated to either place direct pressure on the bleeding site (balloon tamponade) or block the endobronchial lumen proximal to the bleeding site (bronchial blockade). Because these devices block the endobronchial lumen, they are ideally used on subsegmental, segmental or lobar bleeding sites. However, they can be used for complete lung isolation if necessary.

Balloon tamponade is typically achieved under direct visualization by placement of a 4 Fr 100 cm Fogarty balloon catheter (which is inserted through the working channel of a flexible bronchoscope). In contrast, endobronchial blockers are inserted via the endotracheal tube (ETT) under bronchoscopic guidance. Use of a pulmonary artery catheter (PAC) as a blockade device has also been described, and has the advantage of being able to reach smaller subsegmental airways and can be inflated with a known pressure [23,24]. A benefit of a dedicated bronchial blocker is that the bronchoscope can be removed and the blocker left in place, whereas this cannot be done if a Fogarty balloon is inserted via the working channel of the bronchoscope.  

Once a bronchial blocker is placed and the cuff inflated, the bronchoscope is removed and the patient is observed for rebleeding for several hours (up to two days) [25]. Some experts repeat bronchoscopy daily to ensure adequate placement (since catheters easily migrate). After 24 to 48 hours the balloon can be deflated and the patient is observed to ensure that no recurrent bleeding occurs. If there is no evidence of rebleeding, the balloon catheter is removed. Removal does not need to be done under bronchoscopic guidance, although many clinicians perform bronchoscopic surveillance, to ensure hemostasis, and removal simultaneously. There are theoretical risks of ischemic mucosal injury and postobstructive atelectasis and pneumonia due to balloon/blockade devices, but these complications have not been reported.

Reports of successful hemostasis with cellulose, gelatin thrombin, silicone spigots, airway stents and surgical sealants have been described and require the expertise of an interventional bronchoscopist [22,26-30]. (See "Alveolopleural fistula and prolonged air leak in adults", section on 'Bronchoscopic interventions'.)

Further details on bronchial blockers and their placement are provided separately. (See "One lung ventilation: General principles" and "Lung isolation techniques".)

●Ablative therapies – Ablative therapies typically involve the local application of thermal energy to treat bleeding from masses or lesions located in the proximal or major airway (ie, typically trachea and major bronchi). Successful use of laser therapy, electrocautery, argon plasma coagulation (APC), or cryotherapy have been described. These techniques can be implemented through a flexible or rigid bronchoscope; however, rigid bronchoscopy is preferable because it allows better suction capability and provides excellent visualization of the bleeding lesion. Choosing among these bronchoscopic ablative modalities is often at the discretion of the interventionalist; however, cryotherapy is generally not as effective in achieving rapid hemostasis as argon plasma coagulation or laser and delayed hemorrhage is a known complication. (See "Bronchoscopic laser in the management of airway disease in adults" and "Endobronchial electrocautery" and "Bronchoscopic argon plasma coagulation in the management of airway disease in adults" and "Bronchoscopic cryotechniques in adults".)

Chest computed tomography — Early CT of the chest, with and without contrast, should be performed to help localize the bleeding site and facilitate diagnostic investigation. Depending on the stability of the patient, CT may be performed prior to bronchoscopy or afterwards. CT is especially valuable when bronchoscopy is unrevealing [31-37], but is also considered complementary to bronchoscopy since CT examines the parenchyma and mediastinal structures while bronchoscopy examines the major airways down to the fourth order of bronchi (figure 1). CT can identify abnormalities that are difficult to detect by bronchoscopy such as bronchiectasis, which is one of the major causes of life-threatening hemoptysis (table 2), subsegmental lung cancer, cavities that might suggest tuberculosis or a lung abscess, fungal infections (eg, aspergilloma), vascular fistulas, aortic or pulmonary artery aneurysms, arteriovenous malformations, other parenchymal infections, and interstitial lung disease. It is useful to obtain a non-contrast chest CT prior to a contrast CT as the non-contrast study may help differentiate underlying mass lesions from accumulations of blood.

In addition, CT scans may help future interventional or surgical decisions by defining the anatomical location or arterial supply to the lobe/lesion suspected to be the causes of hemoptysis. Features suggestive of a systemic blood supply include increased pleural thickness (>3 mm) adjacent to a parenchymal lesion and/or enhanced vascular structures in a nearby extrapleural fat layer [38]. Occasionally, CT, however, may provide misleading results. As an example, a clot in an airway or bleeding into a cavity may be mistaken as a tumor mass on CT scan, although this will be readily determined by bronchoscopy.

Triage for early surgery — In rare circumstances, early assessment by thoracic surgery is prudent at this juncture for select patients. For example, patients with life-threatening bleeding due to tracheoinnominate artery fistulas, pulmonary artery rupture, and chest trauma are candidates for urgent surgery. (See 'Surgery' below and 'Special populations' below.)

Other patients who may require specific treatment (eg, patients with diffuse alveolar hemorrhage) are discussed separately. (See 'Special populations' below and "The diffuse alveolar hemorrhage syndromes".)

INTERMITTENT OR SLOWED HEMOPTYSIS — In many cases, initial measures are successful in slowing the hemoptysis, allowing time for a more detailed diagnostic investigation and a plan for definitive therapy. It is reasonable to repeat bronchoscopy to perform a more careful diagnostic and/or therapeutic evaluation, since visualization and diagnostic sensitivity may be poor during acute pulmonary hemorrhage. Further testing is dictated by the suspected etiology (table 1).

Etiology-specific testing may involve any one or more of the following:

●Repeat bronchoscopy may be performed for a suspected Dieulafoy lesion or clearer definition of a bleeding lesion as well as for obtaining cultures (for suspected fungal, mycobacterial, or parasitic infection) or for biopsy of suspected endobronchial malignant or benign tumor (eg, transbronchial, bronchial, transthoracic).

●Echocardiography may be indicated for suspected cardiovascular causes (eg, mitral stenosis or right ventricle hypertrophy to suggest pulmonary hypertension [PH]).

●Arteriography (systemic and/or pulmonary) may be warranted when pulmonary aneurysms and arteriovenous malformations are suspected.

●Transthoracic or surgical lung biopsy may be needed for suspected endometriosis, amyloid, or idiopathic pulmonary hemosiderosis.

●Rarely, computed tomography (CT) pulmonary arteriogram may be indicated in patients with suspected pulmonary embolism.

●Other rare tests include pulmonary artery catheterization (for suspected PH or pulmonary veno-occlusive disease); D-dimer (for disseminated intravascular coagulation), toxicity screen (suspected cocaine use); and serology, urinalysis, and renal biopsy (for suspected vasculitis).  

A summary of potential testing strategies based upon presentation and treatment of non-life-threatening hemoptysis is provided separately. (See "Evaluation of nonlife-threatening hemoptysis in adults", section on 'Directed evaluation based on presentation' and 'Definitive treatment' below.)

Once a cause is determined, targeted therapy should begin promptly (eg, external beam radiation for lung carcinoma). (See 'Definitive treatment' below.)

CONTINUED OR RECURRENT LIFE-THREATENING BLEEDING — For patients in whom life-threatening bleeding continues despite initial measures, consideration should be given to the following:

●Additional airway protection options (eg, single lung ventilation or double-lumen endotracheal intubation) (see "One lung ventilation: General principles" and "Lung isolation techniques" and "Anesthesia for video-assisted thoracoscopic surgery (VATS) for pulmonary resection")

●Arteriography and embolization (see 'Arteriography' below)

In addition, the following interventions may apply to individual patients:

●Local bronchoscopic ablation – Patients with life-threatening bleeding who have an identified source of bleeding on bronchoscopy (eg, Dieulafoy lesion, endobronchial tumor) may also be candidates for local thermal ablation (eg, argon plasma coagulation; rigid bronchoscopy may be required) [39-41]. (See "Bronchoscopic argon plasma coagulation in the management of airway disease in adults".)  

●Surgical re-consultation – If not already involved, early thoracic surgical consultation is also warranted in this population. Surgery is reserved for those refractory to arteriography or local measures or for those with life-threatening bleeding from vascular lesions requiring urgent repair (eg, aortic aneurysm rupture or fistula). (See 'Surgery' below.)

●Treatment of the underlying disorder – Patients with diffuse alveolar hemorrhage (DAH) are not treatable with arteriography or local therapies and continued aggressive therapy targeted the underlying cause is necessary. (See 'Special populations' below and "The diffuse alveolar hemorrhage syndromes", section on 'Treatment'.)

●Re-consider pseudohemoptysis – It is also prudent at this point to reconsider other potential sources of bleeding (ie, from the upper respiratory or gastrointestinal tract), particularly if the patient is hemodynamically unstable and has no obvious source of bleeding on bronchoscopy.

Additional airway protection options — Lung isolation techniques are not always necessary but can be performed in those with limited cardiopulmonary reserve or severe hypoxemia as a measure to protect the non-bleeding lung. Among the options, we prefer single lung ventilation. We prefer single lung ventilation since it can be more readily performed and can be combined with placement of bronchial blockers if needed. It is typically employed after bronchoscopy when the bleeding side is known.

●Single lung ventilation – Single (unilateral) lung ventilation is an option in patients with life-threatening bleeding when the bleeding side is known (or confidently presumed). The goal of single lung ventilation is for the inflated cuff of the endotracheal tube to protect the nonbleeding lung from the spillage of blood, thereby maintaining oxygenation and ventilation of the unaffected lung. Thus, a patient whose right lung is bleeding should have the left mainstem bronchus intubated, whereas a patient whose left lung is bleeding should have the right mainstem bronchus intubated. A potential problem with right mainstem bronchial intubation is that the right upper lobe bronchus may become blocked (by the cuff) since its anatomical location is close to the main carina. However, it may be more difficult to selectively intubate the left mainstem bronchus compared with the right unless it is performed under bronchoscopic visualization, since the branching for the left mainstem bronchus is more acute than the right.

One disadvantage of unilateral lung ventilation is that the endotracheal tube (ETT) has to be pulled back to a tracheal location for bronchoscopy to be performed, risking spillage of blood to the nonbleeding lung. However, after bronchoscopy, unilateral lung ventilation on the nonbleeding side may be combined with use of a bronchial blocker/balloon tamponade on the bleeding side. Further details of this technique and bronchial blockade are provided separately. (See "One lung ventilation: General principles" and "Lung isolation techniques".)

●Double-lumen endotracheal tubes – Use of double-lumen endotracheal tubes is usually limited to patients who are exsanguinating and/or asphyxiating from bleeding, patients who cannot be ventilated adequately with single lung ventilation. Personnel need to be experienced in placement and maintenance of double-lumen tubes for safe utilization.

Double-lumen ETTs have two separate lumens (right and left), each with a separate cuff and with differing lengths to the bronchial and tracheal orifices (figure 2 and figure 3) [42]. Mechanical ventilation using a double-lumen ETT permits ventilation of both lungs, while preventing the spillage of blood from one lung to the other. However, they are difficult to insert, especially when patients are bleeding rapidly. Even if the tube is successfully inserted, maintaining its proper position is difficult. Patients typically need to be paralyzed because the tube may easily shift position if the patient moves or even coughs, potentially leading to blood spillage or airway obstruction. Patient transport is generally limited when double-lumen ETTs are in place. In addition, each lumen is relatively small, which predisposes obstruction by thrombus and precludes the passage of most standard and therapeutic bronchoscopes. When bronchoscopy is indicated, this often necessitates changing to an ETT with a lumen large enough for therapeutic procedures.

Generally, a left-sided double-lumen tube is preferred over the right-sided tube, as it is technically easier to insert and avoids possible obstruction of the right upper lobe bronchus when the bronchial balloon cuff is inflated. With the left-sided tube, the longer (bronchial) lumen terminates within the left main bronchus, while the shorter (tracheal) lumen terminates in the distal trachea. After insertion, the bronchial cuff is inflated within the left main bronchus to prevent blood or secretions passing from one side to the other. A separate cuff is inflated within the trachea, just cephalad to the orifice of the shorter (tracheal) lumen.

Ideally, correct placement is ascertained by bronchoscopy through both the tracheal and bronchial lumens, using a small bronchoscope (eg, newer 4 mm bronchoscopes [2 mm channel]; ear, nose, and throat endoscopes; pediatric bronchoscopes; or some bedside disposable bronchoscopes). When examining the tracheal lumen, the main carina dividing the right and left main bronchi should be visualized approximately 2 cm distal to the tracheal lumen orifice. The bronchial cuff should be about 5 mm distal to the main carina without herniation across the carina. When the bronchoscope is passed through the longer (bronchial) lumen, the carina between the left upper and lower bronchi should be visible. A chest radiograph should be subsequently obtained to assess correct positioning by identifying the radio-opaque strip on the double-lumen tube.

Further details of this technique are provided separately. (See "One lung ventilation: General principles" and "Lung isolation techniques".)

Arteriography — Patients with persistent, life-threatening bleeding despite initial measures, bronchoscopy, and/or chest computed tomography (CT) generally undergo arteriography [43-47]. Arteriography can localize the potential bleeding site as well as treat the bleeding by embolization. The preceding bronchoscopy and/or chest CT may be helpful in identifying the bleeding side or lobe, thereby assisting the interventional/vascular radiologist in locating the precise bleeding site.

Procedure and embolization — Arteriography is performed in a radiological suite and therefore requires patient transport. During arteriography, contrast material is injected in the circulation of interest and a search is made for abnormal vascular structures or a focal hypervascularized site with tortuous vessels (eg, bronchiectasis or Dieulafoy lesion). However, the findings of tortuous vessels do not strictly prove that this is the bleeding site. Observation of actual bleeding (contrast extravasation) from a specific vessel into the airway is very rare since the bleeding rate is rarely sufficient (ie, >1 mL/min) for detection by arteriography. Thus, significant clinical judgement is typically needed during arteriography so that the potential bleeding vessel can be safely embolized.

Embolization is usually achieved by inserting occlusive material (eg, coils, vascular plugs) into either the suspected bleeding vessel itself or the proximal vessels that supply the bleeding vessel. No embolization is performed if no convincing “culprit” lesion is found.

The clinical likelihood that bleeding is from the pulmonary, bronchial, or systemic arterial circulation usually determines which circulation is studied first. In general, in 90 percent of patients with life-threatening hemoptysis, bleeding arises from the high-pressure bronchial circulation. Approximately 5 percent arise from the low-pressure pulmonary artery system, and the remaining 5 percent of bleeding events arise from the aorta or non-bronchial systemic circulation (eg, intercostal, coronary, thoracic, axillary, subclavian, and upper and lower inferior phrenic arteries) [9,10]. Thus, in most cases, bronchial arteriography is performed first unless a pulmonary arterial source is suggested (eg, pulmonary arteriovenous malformations [PAVMs], Rasmussen aneurysms, iatrogenic pulmonary artery tears, pulmonary embolism/infarction). The systemic circulation is typically studied when bronchial circulation arteriography has been unrevealing and life-threatening hemoptysis continues (eg, an anatomic variant is suspected). However, some centers routinely perform thoracic aortography after bronchial artery embolization to improve the detection of bleeding from the systemic circulation [48].  

●Bronchial arteriography – The bronchial arteries should be the first vessels studied in most patients with life-threatening hemoptysis because they are the most common source of bleeding. However, bronchial arteriography has the following limitations:

•The anterior spinal artery arises from a bronchial artery in approximately 5 percent of the population. As a result, cannulation or proximal embolization of the bronchial artery may block flow to the anterior spinal cord, resulting in spinal cord ischemia or infarction resulting in paraplegia. Bronchial arteriography should only be performed by experienced operators because the risk of paraplegia is less than 1 percent in experienced hands. Patients should be counseled about this risk as part of the informed consent for the procedure. (See 'Efficacy and adverse effects' below.)

•A significant amount of anatomic variability in the number and location of the bronchial arteries is common. Most individuals have one or two bronchial arteries on each side and a total of three or four arteries. Bronchial arteries usually arise from the aorta, but sometimes they originate from the intercostal arteries.

•Many chronic inflammatory lung lesions are jointly supplied by hypertrophied bronchial arteries and by collateral systemic arteries arising from the subclavian, axillary, intercostal, phrenic, or other arteries. Bleeding that arises from these other systemic arteries will not be visualized by bronchial arteriography.

●Systemic arteriography – It is uncertain when potential systemic arterial supply (intercostal arteries, etc) should be evaluated; examining each potential systemic arterial source can be a long and painstaking task that can increase the dye load substantially. Generally speaking, we believe that patients with life-threatening hemoptysis who do not have a bleeding site identified by the combination of bronchoscopy, bronchial arteriography, and pulmonary arteriography should have their relevant systemic arteries examined. In addition, the systemic arteries should be evaluated when there is recurrence of life-threatening hemoptysis, especially if it occurs early after therapeutic embolization.

●Pulmonary arteriography – The pulmonary arteries are generally studied only if bronchial arteriography does not identify a bleeding source or there is a high suspicion for a pulmonary artery source of bleeding. The usual conditions that cause pulmonary arterial bleeding are PAVMs, Rasmussen aneurysms (ie, pulmonary artery pseudoaneurysms) [49,50], iatrogenic pulmonary artery tears (eg, perforation from a Swan-Ganz catheter), or rarely pulmonary embolism/infarction with coagulopathy . Pulmonary arteriography should be performed prior to bronchial arteriography only if there is high suspicion of one of these conditions.

Efficacy and adverse effects — Arteriographic embolization successfully stops the pulmonary hemorrhage in the majority of patients (range 60 to 90 percent and typically more than 85 percent of attempted embolizations) [51-58]. This is particularly the case when the bronchial, pulmonary, and/or systemic arterial circulations are well defined during the procedure. Early technical failures occur in 5 to 10 percent of attempted embolizations. Reasons for failure include the inability to cannulate the bronchial artery and failure to identify and/or embolize all of the collateral systemic feeder vessels (collateral systemic feeder vessels may arise from the gastric, intercostal, internal mammary, renal, or hepatic arteries) [52,59-62]. About 10 to 20 percent of patients rebleeding over the following 6 to 12 months [53,63-67]. Rebleeding may be due to incomplete embolization, revascularization, or recanalization. Risk factors for recurrence include bleeding from aspergillomas, tuberculosis, bronchiectasis, non-bronchial systemic collateral vessels, and bronchopulmonary shunting [67,68].

Complications of arteriographic embolization include bronchial wall necrosis and ischemic myelopathy (which is due to inadvertent embolization of a spinal artery during bronchial artery embolization) [69]. The risk of myelopathy is less than 1 percent in experienced hands. Best illustrating this low rate was a retrospective study of over 8500 patients who underwent bronchial artery embolization (BAE) for hemoptysis [70]. Among these patients, the prevalence of spinal cord infarction was 0.19 percent. The rate of spinal cord infarction may have been influenced by the embolization material used during the procedure with lower rates in patients who had BAE with coils (0.06 percent) and gelatin sponge particles (0.18 percent), and higher rates in those who had BAE with N-butyl-2-cyanoacrylate (NBCA; 0.71 percent).

Other rare complications include transient chest pain and dysphagia, non-target embolization to the esophagus, brain (resulting in cortical blindness), and pulmonary circulation. Such complications are uncommon when experienced operators perform the procedure [71].

Local ablative techniques — When life-threatening bleeding continues and bronchoscopy has identified an endobronchial source, clinicians may choose arteriography or local thermal ablative techniques or both. Choosing among these is dependent upon local expertise and technical factors that may influence the ability of either procedure to be successful. (See "Clinical presentation, diagnostic evaluation, and management of malignant central airway obstruction in adults", section on 'Bronchoscopic ablative therapies'.)

REFRACTORY BLEEDING — Most patients improve with initial measures, bronchoscopic interventions, and when indicated, arteriography and embolization. However, some patients may have persistent or recurrent hemoptysis despite such interventions. In such cases, repeating previous interventions (eg, ablation via rigid bronchoscopy or arteriography) or evaluating for surgery is appropriate.

Surgery — Surgery (typically a lobectomy), is rarely needed and is reserved for patients who fail bronchoscopic or arteriographic interventions.

Early surgery is indicated in exceptional circumstances, such as tracheoinnominate artery fistulas, pulmonary artery rupture, complex arteriovenous malformations (AVMs) that fail embolization, refractory bleeding from an aspergilloma, and chest trauma. (See 'Triage for early surgery' above.)

Patients with life-threatening hemoptysis are generally too ill for routine preoperative physiologic testing (eg, pulmonary function tests). Thus, historical data (if available) must be used to estimate the patient's ability to undergo lung resection. Relative contraindications to surgery include severe or diffuse underlying pulmonary disease (eg, cystic fibrosis, multiple AVMs, multifocal bronchiectasis, diffuse alveolar hemorrhage) and active tuberculosis. (See "Preoperative physiologic pulmonary evaluation for lung resection".)

The morbidity and mortality of emergent surgery for persistent life-threatening bleeding are greater than the morbidity and mortality of elective surgery in a nonbleeding patient. In older series of emergent therapy for life-threatening hemoptysis, surgical morbidity was 25 to 50 percent and surgical mortality was approximately 20 percent [17]. However, data since then suggest somewhat lower rates of morbidity (26 to 31 percent) and mortality (2 to 7 percent) [72,73].

Common complications of surgery for life-threatening hemoptysis include empyema and bronchopleural fistula. Less common complications include postoperative pulmonary hemorrhage, lung infarction, respiratory insufficiency, wound infection, and hemothorax. (See "Sequelae and complications of pneumonectomy".)

Others — For patients who are not surgical candidates, repeating non-surgical options or administering recombinant factor VIIa, or tranexamic acid may be considered. (See 'Correct bleeding diathesis' above and "Use of blood products in the critically ill" and "Recombinant factor VIIa: Administration and adverse effects", section on 'CNS bleeding'.)

SPECIAL POPULATIONS — Certain populations deserve specific attention.

●Diffuse alveolar hemorrhage (DAH) – Life-threatening hemoptysis from DAH is not treatable with arterial embolization or bronchoscopic methods due to the diffuse nature of bleeding. However, patients with DAH from pulmonary-renal syndrome may require specific serologic tests and early diagnostic biopsies. Patients with DAH from mitral stenosis should have an urgent cardiology consultation. Treatment is targeted at the underlying cause. Interventions are based on the likely diagnosis and may include systemic glucocorticoids, additional immunosuppressive agents (eg, cytotoxic or biologic agents), therapeutic apheresis (eg, anti-glomerular basement membrane disease), or surgery (eg, severe mitral stenosis). Rarely, in patients with severe refractory hypoxemia due to DAH from mitral stenosis, cardiopulmonary bypass may be lifesaving by both treating hypoxemia and by reducing pulmonary venous pressure and bleeding, although the associated anticoagulation can potentially worsen bleeding. (See "The diffuse alveolar hemorrhage syndromes".)

●Tracheoinnominate artery and other vascular fistulas – Life-threatening hemoptysis from a tracheoinnominate artery or other vascular fistulas (eg, aorta) generally is an indication for immediate surgery. Bedside interventions that may help limit the loss of blood from a tracheoinnominate artery fistula prior to surgery are described separately. (See "Tracheostomy: Rationale, indications, and contraindications".)

●Iatrogenic pulmonary artery rupture and chest trauma – Hemoptysis from iatrogenic pulmonary artery rupture or from significant chest trauma also requires immediate surgery to avoid devastating exsanguination. (See "Management of thoracic aortic aneurysm in adults", section on 'Thoracic aneurysm repair' and "Initial evaluation and management of chest wall trauma in adults".)

●Parenchymal lung infection - The threshold for surgery is higher than usual in patients who have pulmonary hemorrhage from parenchymal lung infection since the risk of wound dehiscence from anastomotic infection is high.

●Lesions causing central airway obstruction – The approach to hemoptysis in the setting of life-threatening central airway obstruction (CAO) should focus on airway management and debulking of obstructing lesions, which are most often from lung cancer; in many cases this can be achieved with local ablative bronchoscopic therapies or radiation. Further details are provided separately. (See "Clinical presentation, diagnostic evaluation, and management of malignant central airway obstruction in adults".)

DEFINITIVE TREATMENT — Definitive therapy for life-threatening hemoptysis is treatment of the underlying cause. Bronchiectasis, tuberculosis, bronchogenic carcinoma, and various lung infections are the most common causes of hemoptysis and their treatment is reviewed separately. (See "Bronchiectasis in adults: Treatment of acute and recurrent exacerbations" and "Treatment of drug-susceptible pulmonary tuberculosis in nonpregnant adults without HIV infection" and "Treatment of drug-susceptible pulmonary tuberculosis in nonpregnant adults with HIV infection: Initiation of therapy" and "Overview of the initial treatment and prognosis of lung cancer".)

PROGNOSIS — Studies since 2000 report mortality rates ranging from 7 to 30 percent [74-76]. Several predictors of poor prognosis have been identified [74,76,77]. These include the following:

●Poor performance status

●Advanced stage of malignancy

●Mechanical ventilation (particularly the need for single lung ventilation)

●Hypotension

●Presence of cavitation or necrosis or lung densities involving two or more quadrants on chest radiograph

●Bleeding from the pulmonary artery, cancer, aspergillosis

●Alcoholism

●Aspiration of blood into the contralateral lung

Several retrospective cohort studies have compared outcomes in patients with life-threatening hemoptysis who have non-surgical interventions with those who have undergone surgery [17,76]. Data suggest that the mortality associated with non-surgical therapies and surgery are similar among patients who qualified as surgical candidates.

Recurrence rates are poorly documented, although some studies suggest higher rates in those who undergo arteriographic embolization compared with those who do not require embolization [65,78]. (See 'Arteriography' above.)

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".)

SUMMARY AND RECOMMENDATIONS

●Life-threatening hemoptysis is that which results in life-threatening significant airway obstruction, significant abnormal gas exchange, or hemodynamic instability. We also consider hemoptysis to be life-threatening when there has been approximately 150 mL of blood expectorated in a 24-hour period (easily quantifiable by patients as roughly a half cup of blood in 24 hours) or bleeding at a rate ≥100 mL/hour. The most common etiologies for life-threatening hemoptysis are bronchiectasis, bronchogenic cancer, tuberculosis, and fungal infections (table 2). (See 'Definition' above and "Etiology of hemoptysis in adults", section on 'Causes of life-threatening hemoptysis'.)

●When a patient presents with life-threatening hemoptysis, the initial steps are to ensure adequate oxygenation and ventilation, secure the airway (eg, with a wide-bore 8 mm endotracheal tube), position the patient (lateral decubitus with bleeding side down), ensure hemodynamic stability, and perform initial measures to control the bleeding (eg, treat any bleeding diathesis). In many cases, clinical assessment (table 3 and table 4 and table 5) and diagnostic testing must occur simultaneously with ongoing efforts to stabilize the patient and control the bleeding (table 6). Most patients should be admitted to the intensive care unit. (See 'Initial life-saving and supportive measures' above.)

●Bronchoscopy is an important early test because it can be both diagnostic and therapeutic (eg, iced saline, topical medications, bronchial balloon or blockade devices, or thermal ablation), and may also guide future angiography. For patients who are stable, non-contrast and contrast chest computed tomography (CT) provides complementary diagnostic information to bronchoscopy. Early assessment for the need for surgery is prudent for select populations such as those with bleeding from a tracheoinnominate artery fistula, ruptured pulmonary artery, refractory bleeding from an aspergilloma, or chest trauma. (See 'Initial bronchoscopy' above and 'Chest computed tomography' above.)

●In many patients, initial measures are successful in slowing the hemoptysis, allowing time for a more detailed diagnostic investigation and generation of a therapeutic plan. Further testing is dictated by the suspected etiology (table 1). Etiology-specific testing may include repeat bronchoscopy (for reinspection and acquisition of cultures, cytology, and biopsy), echocardiography, arteriography, CT pulmonary angiography, pulmonary artery catheterization, serology, urinalysis and/or renal biopsy, and toxicity screen. (See 'Intermittent or slowed hemoptysis' above and "Evaluation of nonlife-threatening hemoptysis in adults".)

●For most patients in whom life-threatening bleeding continues or is recurrent despite initial measures, additional airway protection options may be necessary (eg, single lung ventilation or rarely double-lumen endotracheal intubation). For most patients, arteriography (typically bronchial arteriography) with a view to identifying and embolizing a culprit lesion is appropriate. Patients with life-threatening bleeding who have an identified source of bleeding on bronchoscopy may also be candidates for local thermal ablation (or radiation). Thoracic surgical re-consultation is warranted in this population. (See 'Continued or recurrent life-threatening bleeding' above.)

●For patients with refractory life-threatening hemoptysis, repeating previous interventions (eg, ablation via rigid bronchoscopy or arteriography) or evaluating for surgery is appropriate. (See 'Refractory bleeding' above.)

●Several rare causes of life-threatening hemoptysis necessitate specific treatment. (See 'Special populations' above.)

•Patients with vascular fistulas or aneurysms should be evaluated for urgent surgical therapy.

•The threshold for surgery should be higher for those with life-threatening hemoptysis due to infection (eg, abscess) to avoid complications such as bronchopleural fistula and empyema.

•Patients with diffuse alveolar hemorrhage (DAH) are not treatable with arteriography or local therapies and continued aggressive therapy targeted the underlying cause is necessary.

•The approach to hemoptysis in the setting of life-threatening central airway obstruction (CAO) should focus on airway management and debulking of obstructing lesions, which can typically be achieved with local ablative bronchoscopic therapies or external beam radiation when CAO is due to lung cancer.

●Once a cause is determined and the patient stabilized, definitive therapy directed at the cause should begin promptly (eg, external beam radiation for lung carcinoma) (table 1). (See 'Definitive treatment' above.)

●Mortality rates range from 7 to 30 percent. Predictors include poor performance status, advanced stage of malignancy, mechanical ventilation (particularly the need for single lung ventilation), hypotension, presence of cavitation or necrosis or lung densities involving two or more quadrants on chest radiograph, bleeding from the pulmonary artery, cancer, aspergillosis, alcoholism, and aspiration of blood into the contralateral lung. Recurrence rates may be higher in those who undergo arteriographic embolization compared with those who do not require embolization. (See 'Prognosis' above.)