Chest Tubes And ECMO
Chest tubes can significantly contribute to complications in respiratory ECMO patients primarily due to bleeding from the chest wall into the chest cavity. One internal chest wound can seriously complicate ECMO efficacy and the need for a second tube amplifies the problems. One 2002 article showed that of 67 neonatal congenital diaphragmatic hernia (non-ECMO) patients, all of the 11 who received chest tubes died (1). The need for the chest tube insertion may have been a reflection of the increased the severity of the disease. But complications from the tube itself may also have contributed to the morbidity. (Since this article was originally written in 2012, there have been at least two conflicting articles concerning the risks of chest tube use before and during ECMO (2,3).)
Chest tube insertion in non-ECMO, adult trauma patients has a complication rate of 25% (4). The failure rate of small-bore, wire-guided chest drains is as high as 37%, necessitating the need for placement of a second tube (5).
My past experience has shown that non-functional chest tubes should not be removed after the initiation of ECMO due to the high risk of internal bleeding. Also, chest tubes should not be inserted once ECMO has been initiated except in the direst of circumstances. It is possible to avoid chest tube placement in up to 86% of non-ECMO patients on positive pressure ventilation with occult pneumothoraces (6). So, upon the development of a pneumothorax, consideration should first be given to reducing the ventilator pressure and rate followed by an increase in ECMO blood flow if needed. If the pneumothorax is not impacting the cardiac or ECMO function, it should be closely followed and allowed to passively absorb. Eliminating chest tube insertion would avoid subjecting one-in-four patients to the risk of major chest tube-related insertional, positional and infective complications, not to mention the bleeding complications associated with a heparinzed patient on ECMO (7).
The initiation of VV ECMO should be seriously considered before chest tube placement is made in respiratory disease patients who develop pneumothorax. The choice of chest tube placement versus VV ECMO is a difficult decision that must be based on clinical experience rather than discrete criteria. A patient may not meet the aADO2 or OI criteria for ECMO. However, the development of a pneumothorax may signify the enhanced fragility of the lungs to aggressive ventilator settings before accepted respiratory ECMO criteria are met. The need for multiple chest tubes is in itself often an indication of the need for VV ECMO. But, multiple tubes placed before ECMO can result in serious internal bleeding complications after the patient is heparinized. This situation may also require the need for VA ECMO rather than the less invasive VV cannulation. In post-cardiotomy ECMO patients the risk is much less due to the intraoperative placement of chest drains without intercostal wounds and the ability to easily re-access the chest should a tamponade occur.