In adults, the pericardial cavity normally contains less than 20 to 25 ml of fluid. The hemodynamic tolerance to a pericardial effusion depends on its volume (and the pressure exerted on the heart cavities, especially the right ones) on its speed of installation: the increase in pressure in the pericardial cavity leads to compression of the cardiac cavities and a decrease in their diastolic compliance, i.e. a decreased preload and a decreased cardiac output that is compensated by tachycardia and peripheral vasoconstriction. The equalization of intrapericardial and intracardiac pressures results in an almost complete interruption of the cardiac filling.

Normally, spontaneous ventilation influences the filling of the cardiac cavities: inspiration increases the venous return to and volume of the R.V. with slight displacement of the interventricular septum toward the LV, and vice versa in expiration. In case of pericardial effusion, these variations in ventricular volumes are no longer dampened by the pericardium: in other words, in inspiration, the leftward displacement of the septum is exaggerated and results in decreased filling of the LV, causing a pulsus paradoxus (defined as a decreased pulse and arterial pressure of more than 10 mmHg at the end of inspiration, which is also visible on the  plethysmogram of the pulse oximeter).

Auscultation: muffled heart sounds.

At the ECG: tachycardia, microvoltage and electrical alternance. Dyspnea is sign of poor tolerance.

In case of viral pericarditis, beware of any associated myocarditis.

Cholesterol crystal pericarditis [MIM 260 900] is rare, of recessive autosomal transmission and generally not very symptomatic. It often evolves into constrictive pericarditis with calcifications.

Tamponade:

The classic clinical signs of a tamponade are: decreased arterial blood pressure, high venous pressure (distended jugular veins), distant and muffled heart sounds (Beck's triad) and a pulsus paradoxus.

However, in newborns or infants with tachycardia, these signs are often absent and the pulsus paradoxus is difficult to elicit. In addition,  a pulsus paradoxus cannot be observed in the presence of an intracardiac shunt. ECG: microvoltage and electrical alternance. The diagnosis is made by echocardiography: collapse of RA and RV in diastole, no inspirational collapse of the IVC.

This pathology should be kept in mind in the case of sudden unexplained hemodynamic deterioration in a small child presenting with one of the aforementioned at risk situations. In fact, fluid  accumulates gradually in the pericardial cavity and hemodynamic decompensation occurs when intra-pericardial pressure equals central venous pressure and interferes with cardiac filling.

Treatment:

-        in case of extreme emergency, the heart cavities can be quickly decompressed by echoguided puncture of the pericardium: a needle mounted on a syringe is inserted just next to the xyphoid process (on the left side) and slowly advanced aiming at the left shoulder. The blood of pericardial origin is incoagulable, unlike the blood originating from an intracardiac puncture.

-        in less urgent cases, it is preferable to carry out the puncture-drainage under anesthesia.

In a retrospective series of 65 children who underwent 79 anesthesias for drainage of a pericardial effusion (53 pericardiocenteses and 12 pericardiotomies), 8 major complications were observed, including 2 cardiac arrests and 4 major hypotension during induction of anesthesia. The predicting factors of a major complication were, in this series, the preoperative presence of tachypnea and/or of ultrasound signs of tamponade.

Anesthetic implications:

1)        in case of pericarditis: risk of associated myocarditis; interactions with medical treatment: NSAIDs, aspirin, colchicin or corticosteroids

2)        in case of tamponade, an elevated CVP should be maintained as well as spontaneous breathing to promote ventricular filling, and  slight tachycardia (any bradycardia is poorly supported). The child is only put asleep when the surgeon is ready to act: small doses of ketamine and/or etomidate are used, and, if necessary, gentle assisted ventilation is provided until the pericardial drainage. An increase in arterial BP is observed as soon as the pericardial effusion is drained.

References : 

-        Musumeci R, Hickey P.
Anesthesia in a neonate with tamponade due to massive pericardial effusion.
Anesth Analg 1994; 78:169-71.

-        Rawlinson E, Bagshaw O.
Anesthesia for children with pericardial effusion: a case series.
Pediatr Anesth 2012; 22: 1124-31.

-        Grocott HP, Gulati H, Srinathan S, Mackensen GB.
Anesthesia and the patient with pericardial disease.
Can J Anesth 2011; 58: 952-66.

Updated: December 2019