Chest drain associated neonatal pneumopericardium

Introduction

Typically, pneumopericardium in a neonate is associated with other air leaks, most commonly pulmonary interstitial emphysema (PIE), pneumothorax, and pneumomediastinum [1, 2]. Air, from ruptured alveoli (due to aggressive resuscitation, mechanical ventilation and/or severe lung pathology, e.g. meconium aspiration), tracks along perivascular and peribronchial sheaths to the mediastinum. From here it is hypothesised to enter the pericardial space along pulmonary veins at the reflection of parietal onto visceral pericardium [3, 4]. With regular early surfactant use in preterm babies and newer modes of synchronised ventilation, pneumopericardia are increasingly infrequent.

We describe the case of a preterm neonate who survived major surgery for a tension pneumopericardium secondary to chest drain placement for a pneumothorax, a previously unreported complication.

Case report

A neonate was born by emergency caesarean section at 27+6 weeks gestation due to severe maternal pre-eclampsia. Antenatal steroids had been administered (two doses of dexamethasone), and the baby had a birthweight of 880 g. He responded well to resuscitation at birth, with APGAR scores of 1, 5, and 8, at 1 min, 5 min, and 10 min, respectively. He was transported to the neonatal unit (NNU) on continuous airway positive pressure (CPAP), but due to increasing oxygen requirement was intubated and given surfactant.

Post-surfactant the baby was ventilated, but a chest radiograph displayed a right-sided pneumothorax for which needle aspiration was performed prior to placement of a pig-tailed chest drain via the Seldinger technique. Over the next few days this showed radiological signs of resolution but once the drain was removed there was re-accumulation of air in the pleural space requiring redrainage (Figure 1).

Figure 1:

Chest radiograph showing residual right sided pneumothorax and chest drain in situ.

The baby was otherwise haemodynamically stable, with a satisfactory mean arterial blood pressure without inotropic support, although he received several fluid boluses (10 mL/kg 0.9% NaCl) and sodium bicarbonate corrections for an initially persistent metabolic acidosis. C-reactive protein (CRP) rose to 59, but gradually normalised with a course of second line antibiotics (cefotaxime and vancomycin). He was also on parenteral nutrition (PN) via an umbilical venous catheter (UVC).

Subsequent radiographs with the second drain in-situ displayed the classical “halo” sign of a pneumopericardium, [5] which initially resolved by applying suction to the drain, but recurred following its removal. This raised concerns of a bronchopleural fistula with involvement of the pericardium, however, despite replacement of the drain the pneumopericardium continued to increase in size (Figure 2). Clinical deterioration (increasing desaturations and oxygen requirement, and bradycardia and hypotension) indicated a tension pneumopericardium necessitating emergency pericardial drainage.

Figure 2:

Chest radiograph showing large pneumopericardium.

Following this an urgent transfer took place to our local paediatric surgical unit. Initial emergency surgery involved a small subxiphiod incision with drain placement – this normalised the haemodynamics. However, continuing air leak necessitated a median sternotomy. The pericardium was adherent to the right atrium and ventricle, and an iatrogenic perforation in the pericardial surface just adjacent to the inferior caval vein was found which briskly leaked air into the pericardial space. There were no other sources of air leak. The breach in the pericardium was repaired, and drains were placed in the pericardial and right pleural spaces. An incidentally found patent arterial duct was also ligated. The drains were removed 3 days later. Two weeks later, the infant developed mediastinitis necessitating rewiring of sternum. He subsequently developed necrotising enterocolitis (NEC) that required surgical resection of 20 cm of small bowel. He has since been recovering, and is currently self-ventilating in air and slowly increasing feeds while on PN with close monitoring of stoma output.

Discussion

Iatrogenic pneumopericardium due to chest drain placement in a pre-term neonate is an unreported complication, but must be in our differential for a baby who suddenly deteriorates following a drain insertion. Small pneumopericardia can be left to resorb, and in babies not at risk of retinopathy of prematurity (ROP) (i.e. >32 weeks gestation), high concentrations of inhaled oxygen can aid reabsorption through nitrogen washout [6]. However, it is possible for air within the pericardium to have a tamponading effect, similar to fluid (e.g. PN, blood), with significant mortality (death in up to 80% of cases) [2]. Therefore if there is evidence of haemodynamic compromise urgent drainage is required, and in some cases, surgery.

To avoid this complication we would recommend optimising the position of the drain following placement. If imaging shows the drain tip overlying the mediastinum, the chest drain should be withdrawn an appropriate amount and a repeat chest radiograph performed to confirm its position [7, 8].