From the Guidelines

Massive hemoptysis is defined as hemoptysis that can threaten life, with a suggested threshold of >100 mL of expectorated blood in 24 hours.

The definition of massive hemoptysis is not strictly based on the volume of blood expectorated, but rather on the potential threat to life, with factors such as the rate of hemoptysis and coexisting cardiopulmonary comorbidities playing a significant role 1.
The threshold of >100 mL of expectorated blood in 24 hours is suggested, but the quantity of blood loss resulting in death can vary based on individual patient factors 1.

Massive hemoptysis can be clinically subdivided into “clinically unstable” and “clinically stable” categories, with the primary focus in unstable cases being patient stabilization and resuscitation 1.
The management of massive hemoptysis requires securing and maintaining an adequate airway and optimal oxygenation, often necessitating endotracheal intubation 1.

Bronchoscopy is a crucial diagnostic and therapeutic tool in the management of massive hemoptysis, allowing for the identification of the bleeding site and the application of therapeutic interventions such as tamponade or embolization 1.
Computed tomography (CT) with intravenous contrast can be used as a diagnostic tool to identify the cause of bleeding and facilitate preprocedural planning for bronchial artery embolization (BAE) 1.

From the Research

Massive hemoptysis (MH) is a serious condition that carries a high rate of morbidity and mortality 2
It is defined clinically as any bleeding from the tracheobronchial tree that compromises respiratory or circulatory function 2
Massive hemoptysis can be defined as any life-threatening hemoptysis and any hemoptysis that may cause airway obstruction and asphyxia 3
It is appropriately defined as life-threatening hemoptysis that causes airway obstruction, respiratory failure, and/or hypotension 4

The most common cause of massive hemoptysis is tuberculosis worldwide, but bronchiectasis, bronchogenic carcinoma, and mycetoma are more common causes in the U.S. 2
Massive hemoptysis accounts for approximately 5% of all hemoptysis cases and usually indicates the presence of a potentially severe respiratory or systemic disease 3
The mortality rate of massive hemoptysis is about 6.5-38% 3

Patients with massive hemoptysis require rapid assessment and management, as decompensation can be rapid 2
A reasonable order or sequence of management includes initial stabilization; assessment for the need for airway intervention; reversal of any coagulopathy; advanced imaging; and emergent consultation of pulmonary, cardiothoracic surgery, and interventional radiology 2
Early activation and coordinated response from a multidisciplinary team is critical 4
Nonsurgical control of hemorrhage is superior to surgery in the acute situation 4
Surgical resection is still considered the main approach for patients with massive hemoptysis, but the combination of bronchial artery embolization (BAE) and surgery can improve patients' mortality and morbidity 5