What is Pulmonary Infarction (PI) or Embolism (PE)?

From the Guidelines

Pulmonary Infarction (PI) or Embolism (PE) is a potentially fatal disorder with a range of clinical presentations, from haemodynamic instability to silent, and evaluating the likelihood of PE in an individual patient according to the clinical presentation is of utmost importance in the interpretation of diagnostic test results and selection of an appropriate diagnostic strategy. The clinical presentation of PE can vary, but common symptoms include dyspnoea, chest pain, and syncope, either singly or in combination, and can be associated with pleuritic chest pain, isolated dyspnoea of rapid onset, or syncope or shock in severe cases 1.

Clinical Presentation

The clinical presentation of PE can be categorized into different syndromes, including:

• Pleuritic chest pain, which is usually due to distal emboli causing pleural irritation, and a consolidation may be present on chest X-ray
• Isolated dyspnoea of rapid onset, which is usually due to more central PE, not affecting the pleura
• Syncope or shock, which is the hallmark of central PE with severe haemodynamic repercussions, and is accompanied by signs of haemodynamic compromise and reduced heart flow

Diagnosis

The diagnosis of PE is based on a combination of clinical evaluation, laboratory tests, and imaging studies, and the Pulmonary Embolism Severity Index (PESI) and simplified PESI have been most widely validated to predict patient outcomes 1. The clinical evaluation is accurate to discriminate a subgroup of patients with a low likelihood of PE, and clinical probability may be estimated empirically or explicitly by a prediction rule 1.

Management

The management of PE depends on the severity of the disease and the presence of underlying conditions, and home treatment may be offered to patients with PE with a low risk for complications, while hospital treatment is recommended for patients with submassive or massive PE or at high risk for bleeding 1. The treatment of PE involves anticoagulation therapy, and the choice of anticoagulant depends on the patient's underlying conditions and the presence of contraindications.

Key Points

• PE is a potentially fatal disorder with a range of clinical presentations
• Evaluating the likelihood of PE in an individual patient according to the clinical presentation is of utmost importance in the interpretation of diagnostic test results and selection of an appropriate diagnostic strategy
• The clinical presentation of PE can vary, but common symptoms include dyspnoea, chest pain, and syncope
• The diagnosis of PE is based on a combination of clinical evaluation, laboratory tests, and imaging studies
• The management of PE depends on the severity of the disease and the presence of underlying conditions.

From the Research

Definition and Causes

• Pulmonary Infarction (PI) or Embolism (PE) is not directly defined in the provided studies 2, 3, 4, 5, 6.
• The studies primarily focus on eosinophilic pneumonias, tropical pulmonary eosinophilia, and pulmonary eosinophilic infiltrates, which are distinct conditions.
• However, it can be inferred that pulmonary diseases can be caused by various factors, including parasitic infections, medications, autoimmune and inflammatory diseases, and malignancies 3, 4, 5, 6.

Characteristics and Diagnosis

• Eosinophilic pneumonias are characterized by an increase in eosinophils in lung tissue or bronchoalveolar lavage fluid, and may be associated with peripheral blood eosinophilia 2, 3.
• Tropical pulmonary eosinophilia is caused by immunologic hyperresponsiveness to filarial parasites and is distinguished by a patient's history of residence in the tropics, high levels of serum IgE and antifilarial antibodies, and dramatic clinical improvement after treatment with antifilarial drugs 4.
• Pulmonary eosinophilic infiltrates can be idiopathic, secondary, or associated with diffuse lung diseases, and diagnosis requires correlation with laboratory tests, imaging studies, and clinical presentation 6.

Treatment and Prognosis

• Corticosteroids are the mainstay of treatment for many eosinophilic pneumonias, and prognosis is typically excellent if treatment is initiated in a timely manner 2, 3.
• In some cases, immunosuppressants may be necessary, and recent studies have shown that imatinib can be effective in the treatment of certain eosinophilic disorders 2.
• However, delayed diagnosis and treatment can lead to fatal lung disease, highlighting the importance of early and accurate diagnosis 3.