New treatments haven't lowered anesthesia risks for children with pulmonary hypertension

"The risk for adverse events during anesthesia in patients with PHT remains high, despite newer disease-modifying treatments," reports the study by Dr Katherine Taylor and colleagues of the Hospital for Sick Children, Toronto. Younger children and those with more severe disease are at higher risk, but larger studies will be needed to understand the risks of anesthesia in the era of modern treatments for PHT.

Do New Treatments Affect Complications in Children with PHT?

The researchers analyzed adverse events in 122 infants and children with PHT undergoing surgery with general anesthesia between 2008 and 2012. Pulmonary hypertension is a serious condition in which the blood pressure in the arteries of the lungs is too high. Historically, children with PHT have had not only a shortened life expectancy, but also a high risk of serious anesthesia-related complications. As a result, surgery was avoided except in extreme cases.

But in the past five years, new "disease-modifying" treatments have substantially improved survival for infants and children with PHT. "Consequently, patients are now presenting to anesthesia/surgical services for procedures associated with PHT and other childhood and adolescence illnesses," Dr Taylor and coauthors write. They evaluated patterns of complications occurring under current approaches to managing PHT.

The 122 patients, median age 2.2 years, underwent a total of 264 non-heart surgeries. In most patients, PHT was related to congenital heart defects. Forty-three percent of operations were performed while the children were receiving the newer disease-modifying treatments.

Minor complications occurred in about four percent of procedures and major complications in a little over three percent. Three children died, for a risk of about one percent per surgery. These adverse outcome rates were in the range reported by previous studies, before the new PHT treatments were introduced.

Complication rates were somewhat lower for children receiving the new disease-modifying drugs: 4.1 percent versus 8.6 percent for overall complications, and 2.5 versus 3.7 percent for serious complications. However, after adjustment for the severity of PHT, the new treatments had no significant effect on complication risk.

Age and PHT Severity Are Key Risk Factors

On further analysis, rates of complications and death remained significantly higher for children with more severe PHT -- including those receiving home oxygen therapy and those undergoing lengthier surgical procedures. Age was also a strong risk factor, with younger children being at higher risk. The risk of serious complications was six times higher for infants younger than five months, compared to those aged two years or older.

"The risk for adverse events during anesthesia in patients with PHT remains high, despite newer disease-modifying treatments," Dr Taylor and colleagues write. They note that their study is the largest to date of infants and children with PHT, and the only one performed since the effective new PHT treatments were introduced.

Yet the single-hospital study still doesn't include enough events -- a total of nine serious complications and three deaths -- to evaluate the various contributors to adverse events. Collaborative studies including data from multiple hospitals will be needed to address unanswered questions about the risks of surgery and anesthesia in children with PHT, including the role of disease-modifying treatments. Meanwhile, the results provide important information on risk factors for complications in the modern era of PHT treatment -- particularly younger age and greater disease severity.