Pulmonary embolism | Medical Science Optional Notes for UPSC PDF Download

Etiology

• Pulmonary embolism refers to the obstruction of one or more pulmonary arteries by solid, liquid, or gaseous masses.
• Deep vein thrombosis (DVT) is a common cause, and risk factors include immobility, inherited hypercoagulability disorders, pregnancy, recent surgery, dehydration, the use of oral contraceptives, and a history of previous DVT.
• Fat embolism, often associated with multiple closed fractures or endoprosthesis replacement, is another potential cause.
• Amniotic fluid embolism is characterized by the introduction of amniotic fluid into the maternal bloodstream and can occur during childbirth.

Presentation

• Pulmonary embolism (PE) is often referred to as "the Great Masquerader."
• Symptoms typically have an acute onset, frequently triggered by specific events such as rising in the morning or sudden physical strain/exercise.
• Common manifestations include dyspnea and tachypnea (observed in over 50% of cases).
• Sudden chest pain is reported in approximately 50% of cases, worsening with inspiration.
• Cough and hemoptysis may be present.
• Physical examination may reveal potentially decreased breath sounds, dullness on percussion, and in some cases, an audible split-second heart sound.
• Tachycardia is observed in about 25% of cases, along with hypotension.
• Jugular venous distension, low-grade fever, and syncope are possible.
• Massive PE can lead to shock with circulatory collapse, especially in cases involving a saddle thrombus.
• Symptoms of deep vein thrombosis (DVT), such as unilaterally painful leg swelling, may also be present.

Differential Diagnosis

Conditions that may mimic pulmonary embolism (PE) include:

• Pneumonia, asthma, and chronic obstructive pulmonary disease (COPD).
• Congestive heart failure.
• Pericarditis.
• Pleurisy, often labeled as "viral syndrome," costochondritis, and musculoskeletal discomfort.
• Rib fracture and pneumothorax.
• Acute coronary syndrome.
• Anxiety.

Diagnosis

Pulmonary embolism-Well's score

Wells Criteria (Clinical Probability)

• Total score of 0-1: Low probability of PE (approximately 10% likelihood).
• Total score of 2-6: Moderate probability of PE (around 30% likelihood).
• Total score of > 6: High probability of PE (approximately 65% likelihood).

Management

• Anticoagulation:
  • Initial: LMW heparin/Fondaparinux in stable patients (0-10 days).
  • Long-term: Anticoagulation and prophylaxis with warfarin, targeting INR 2-3 (for 3-6 months).
• Massive, life-threatening pulmonary embolism:
  • Recanalization.
  • Thrombolytic therapy (rtPA).
  • Embolectomy.
• IVC filters in case of recurrent DVTs.

Complications

• Recurrence: Approximately 10% in the first year, 5% per year.
• Right ventricular failure.
• Sudden cardiac death.
• Atelectasis.
• Pulmonary effusion.
• Pulmonary infarction.

Pulmonary embolism-Repeats

Q1: An 80-year-old male, bed-ridden for three weeks, develops sudden onset breathlessness, becomes unconscious and was brought to the casualty. (2016)
(i) Discuss the probable etiologies of this episode.
(ii) Outline the investigations required for diagnosis and management.
(iii) Describe the management of acute anterior wall myocardial infarction.
Q2: An elderly woman is bed-ridden for 4 weeks because of a fractured hip. She is brought to the casualty with sudden onset of breathlessness. Enumerate the possible causes of breathlessness in this case .Describe the management of acute pulmonary embolism. (2013)
Q3: A 70-year old male, bed ridden for the last 2 weeks following a fracture of the femoral neck, presented to the medical emergency department with sudden breathlessness and hypotension. What is the likely diagnosis? How would you diagnose this patient? What would be the management for this patient? (2018)