Often, after lifesaving cardiac surgery for congenital heart defects, neonates require help with breathing using a breathing tube and a mechanical ventilator. Deciding when to extubate, or remove the breathing tube and ventilator, after cardiac surgery is an extremely important decision with profound health implications.

Extubation failure in this patient population has been associated with poor clinical outcomes, including increased length of stay, cardiac arrest and mortality.

When we noticed a higher-than-expected extubation-failure rate at Norton Children’s Heart Institute, affiliated with the UofL School of Medicine, we decided to study why and how we could improve. We, along with 71 other cardiac centers, are part of the Pediatric Cardiac Critical Care Consortium (PC4). We decided to leverage this collective to see if, working together with other cardiac centers, we could make improvements in neonatal extubation success rates after cardiac surgery.

We identified five cardiac intensive care units in the collaborative with lower-than-expected neonatal extubation failure rates. We added a balancing metric of expected or better-than-expected duration of postoperative mechanical ventilation.

We then surveyed these high-performing centers by phone about their practices, including the use of spontaneous breathing or extubation readiness trials, steroids, post-extubation respiratory support, criteria for extubation readiness and criteria for high-risk extubations.

Peri-extubation bundle of best practices

Using this information, we created a peri-extubation bundle of best practices for patients less than 60 days old undergoing a cardiac surgical procedure. The bundle includes assessment of heart rate, respiratory rate and ability to breathe with minimal help from the ventilator. We monitor the body’s use of oxygen using near-infrared spectroscopy (NIRS). We also measure how well the lungs are exchanging oxygen and carbon dioxide. The assessment occurs before removing the breathing tube or ventilator. The physician reviews all the results from the trial and makes a decision, based on the specific patient condition and our predefined extubation readiness trial failure cutoffs, whether it is time to remove the breathing tube or not.

We hope to identify those babies who aren’t quite ready to have the tube and ventilator removed. We then can work to make their respiratory status more stable and reassess at a later time. If our bundle is accurate, then we will save babies a failed extubation and the complications that may be associated with it.

Extubation in infants this young is challenging for a number of reasons. They have very small airways, may be weak from sedation, may have known complications related to cardiac surgery, may have heart defects affecting heart function and generally don’t have the opportunity to have optimal nutrition and growth before needing surgery. These babies struggle to breathe on their own if taken off the ventilator too soon.

After the unit staff was trained, we began using our peri-extubation bundle of best practices in January 2022. In the trial, we change the ventilator settings to allow the patient to mimic breathing without the breathing tube while being able to leave the tube in place. It’s a trial run before the real test of removing the tube. If they fail the trial run, we may say they need more time to get stronger before we actually remove the breathing tube.

We have seen a rise in heart rate as the most common reason for an unsuccessful trial. We also look at respiratory rate, apnea and other factors, including how well the lungs are exchanging carbon dioxide and oxygen.

Encouraging early results

To see how well these new practices were working, we compared data from the six month pre-intervention with the first six months of intervention.

In the period before instituting this peri-extubation bundle of best practices, there were 27 extubations in 26 patients. Three patients failed extubation (11.1%). After instituting these new practices, there were 27 extubations in 23 patients, with one extubation failure (3.7%), a 66.7% relative reduction in extubation failure rates.

We plan to collect a year’s worth of data and assess the bundle of best practices, analyze which parts were helpful and which were not. We may keep the bundle the same or change some parts of it.

We’re working with faculty at several other centers to develop and analyze the bundle

Hopefully, when we’re confident we’ve fine-tuned our post-cardiac surgery neonatal extubation practices, we can roll them out to other centers. I’m excited about this, because we’re not only helping kids at Norton Children’s but could help children around the country as well.

Deanna R. Todd Tzanetos, M.D., MSCI, is medical director of the Jennifer Lawrence Cardiac Intensive Care Unit and is a pediatric critical care specialist with Norton Children’s Critical Care, affiliated with the UofL School of Medicine.