Delayed pericardial effusions: life-threatening complication presenting up to 100 days after chest trauma

Discussion

Acute pericardial effusion and cardiac tamponade can follow penetrating cardiac trauma and immediate drainage, followed by surgical exploration and repair, is required. Delayed pericardial effusions following thoracic trauma are much less common but can present unexpectedly, are potentially fatal and are preventable.

Pericardial effusions typically present with dyspnoea. Large effusions may compress local structures causing dysphagia, cough, hoarseness and hiccoughs. Chest radiographs may demonstrate an enlarged ‘globular shaped heart’. Electrocardiography may demonstrate beat to beat variation in the amplitude of the QRS, termed electrical alternans. This manifestation is due to pendular swinging movements of the heart within the effusion. Ultimately, the diagnosis is made using echocardiography.

Delayed pericardial effusions have been reported following both penetrating and blunt trauma to the heart, chest, epigastrium and back.^1–5 All, some or none of the classical features of a pericardial effusion may be present in these patients.²

The cause of delayed effusions remains unclear. Direct but minor trauma to the heart with initial wound occlusion by thrombus and subsequent leakage of blood and exudate may explain some cases.² Sealed-off lacerations have been found on surgical exploration while others report lacerated coronary arteries with thrombus in situ.^3,4 In children and infants blunt trauma to the chest or abdomen has resulted in unexplained haemopericardium.⁶ In older patients, incidental anticoagulant use may contribute.

An alternative explanation in some cases may involve an inflammatory or autoimmune process against the myocardium or pericardium, with a subsequent effusive pericarditis.³ This process is similar to a post-cardiotomy syndrome and the classical Dressler's syndrome that follow myocardial infarction.³ In a series of 24 patients, Harris et al felt that an autoimmune post-cardiotomy type syndrome was the main cause of delayed pericardial effusions – none were found to have cardiac lacerations.² This mechanism is likely to have played a role in the patient presented here. While the blade did not strike the heart, it may have caused an antigenic exposure sufficient to result in an autoimmune response.

In cardiac tamponade, the intrapericardial pressure exceeds intracavity pressure with subsequent cardiac chamber compression and impaired diastolic filling. This leads to circulatory collapse in the form of pulseless electrical activity (PEA). Pericardiocentesis should be performed immediately. A point to note is that in cardiac arrest secondary to tamponade, chest compressions are futile as no cardiac output can be achieved until the effusion is drained.

Pericardiocentesis via the subxiphoid approach, guided by echocardiography, is a safe procedure and life saving.⁷ The injection of contrast through the ‘seeker’ needle may help to alleviate fears of ventricular puncture when the fluid aspirated is haemorrhagic in appearance.⁷ Fluid should be aspirated and an indwelling drainage catheter left in situ on free flow for at least 24 hours. There is no consensus on how long the drain should remain in situ or how quickly to remove the fluid, however, longer drainage may reduce the need for surgical exploration.⁷ Cardiothoracic surgical opinion should be sought as effusions may be loculated or contain thrombus in which case incomplete drainage will lead to rapid reaccumulation. The risk of subsequent pericardial constriction from haemorrhage in the pericardial space should be considered.

A very high suspicion of pericardial effusion and tamponade is required in all patients suffering penetrating trauma. Campbell et al described a case series of 1,198 penetrating cardiac trauma cases, 697 of which were stabbings.⁸ Of these, only 66 patients reached the hospital alive and 202 patients (18%) died of tamponade who could have been saved had prompt pericardiocentesis or thoracotomy been performed.⁸ Seven patients were identified as having cardiac injury missed on surgical exploration, emphasising the need for vigilance even when using an operative strategy.⁸

With knife crime a continuing trend, delayed cardiac effusions and tamponade should be considered and routine arrangements for follow-up echocardiography and review should be made for all stab victims.