Tubes and other flexible equipment used in cardiopulmonary bypass surgery (CPB) have exposed young children to phthalates at levels that may be clinically significant, according to preliminary research.
In one hospital, pediatric patients who received blood products during heart surgery experienced immediate postoperative increases in serum DEHP levels (from a median of about 3 µM preoperatively to about 5 µM, PPP
Younger children tended to have larger phthalate peaks, as post-surgical phthalate levels correlated with more blood products used, longer bypass times, and methylprednisolone use, Devon Guerrelli reported. , MS, from Children’s National Hospital in Washington, at the American Academy of Pediatrics (AAP) virtual meeting.
Although phthalate levels returned to baseline by day 1 postoperatively, children with larger phthalate peaks were more likely to have junctional ectopic tachycardia and hypotension within 24 hours of surgery. Additionally, glucose levels increased with a higher MEHP concentration in particular, and the two patients who suffered cardiac arrests both had MEHP levels 20 to 25 times above the acceptable limit.
MEHP is the most toxic metabolite of DEHP, the most common phthalate plasticizer used in flexible polyvinyl chloride (PVC) medical equipment (eg, tracheal tube, tubing, plastic wrap of red blood cells or RBCs). DEHP, which is not chemically bound to PVC, can enter the bloodstream, and it and its metabolites have been associated with endocrine, reproductive, renal, neurological, hepatic and cardiac toxicity in previous studies.
Without the use of RBC, pediatric CPB was not associated with post-surgical increases in phthalate levels. Guerrelli noted that during storage DEHP seeps into blood products and can be metabolized to MEHP in the bag.
The problem with methylprednisolone may be its increased activity of pancreatic lipase, which is responsible for converting DEHP to MEHP, Guerrelli said.
“Overall, our results indicate that steps should be taken to minimize exposure to DEHP during heart surgery,” she said. His suggestions included:
- Use products without DEHP
- Discontinuation of preoperative methylprednisolone administration
- Decrease in the volume of blood products used
- Choose fresh blood products
The DEHP-free alternatives on the market contain plasticizers which are considered to be less cardiotoxic and are eliminated more slowly.
AAP session co-moderator Juan Villafane, MD, University of Cincinnati, said the study warrants raising a “red flag” indicating that patients could be injured when DEHP products are used during surgery. CPB procedures. Alternative equipment could be used to avoid costly complications, he suggested.
Guerrelli said the cost is the reason hospitals haven’t switched to completely DEHP-free products – some components can cost up to four times as much.
Guerrelli’s group conducted the study using routine plasma samples from 53 children undergoing heart surgery. The sample had taken place preoperatively, immediately after surgery when the child had gone to the cardiac ICU, then a day later to the cardiac ICU.
Clinical data was collected from the facility’s electronic health records.
The study was limited by the small sample size and monocentric nature. Investigators continue to probe the effect of phthalates in CPB along with data from 50 other patients, Guerrelli said.
The study was supported by the NIH.
Guerrelli did not disclose any conflict.