From the Guidelines
Unexpected cardiopulmonary arrest can be caused by various factors, including cardiac and non-cardiac etiologies, with pulmonary embolism (PE) being a significant contributor.
Causes of Cardiopulmonary Arrest
- Cardiac causes: myocardial infarction, electric disturbances, and cardiac tamponade 1
- Non-cardiac causes:
Pathophysiology of Pulmonary Embolism
Pulmonary embolism can lead to haemodynamic instability, characterized by cardiac arrest, obstructive shock, persistent hypotension, and need for cardiopulmonary resuscitation 1. The blockage of pulmonary arteries results in ventilation/perfusion mismatch, contributing to hypoxaemia. In some cases, right-to-left shunting through a patent foramen ovale can occur, leading to severe hypoxaemia and increased risk of paradoxical embolization and stroke 1.
Clinical Presentation
The clinical presentation of pulmonary embolism can range from mild to severe, with symptoms such as haemoptysis, pleuritis, and pleural effusion, known as "pulmonary infarction" 1. Acute right ventricular (RV) failure is a critical determinant of clinical severity and outcome in acute PE, with clinical symptoms and signs of overt RV failure and haemodynamic instability indicating a high risk of early mortality 1.
From the Research
Causes of Cardiopulmonary Arrest
The causes of unexpected cardiopulmonary (cardiac and pulmonary) arrest can be varied and complex. Some of the key causes include:
- Inherited arrhythmia syndromes, such as long QT syndrome and Brugada syndrome, which can lead to cardiac arrest 2
- Potentially reversible causes, including hypoxia, hypovolaemia, hyperkalaemia, hypothermia, thrombosis, tamponade, tension pneumothorax, and toxic agents 3
- Respiratory and metabolic derangements, which are common precursors to cardiopulmonary arrest in hospital settings 4
- Cardiac causes, such as myocardial infarction and cardiac arrhythmias, although these may be less common than previously thought 5
- Acute massive pulmonary thromboembolism, which can cause cardiac arrest and has a high mortality rate 6
Specific Etiologies
Some specific etiologies of cardiopulmonary arrest include:
- Respiratory failure, which is a common cause of arrest 5
- Cardiac causes, such as myocardial infarction and cardiac arrhythmias 5
- Pulmonary embolism, which can cause cardiac arrest and has a high mortality rate 6
- Other medical conditions, such as sepsis, trauma, and stroke, which can also lead to cardiopulmonary arrest 3, 4
Importance of Diagnosis and Management
Accurate diagnosis and management of the underlying cause of cardiopulmonary arrest are crucial for improving patient outcomes. This may involve the use of point-of-care ultrasound, extracorporeal CPR, and other interventions to identify and treat the underlying cause of the arrest 3, 6.