Need to Know Kids' Weight in the ED? Parents Often Know Best

October 4th, 2016

LOS ANGELES – When emergency physicians need to estimate the weight of a pediatric patient, asking Mom or Dad works about as well as or better than more sophisticated measurement systems.

That’s according to the results of a systematic review of the literature on pediatric weight estimation published online in Annals of Emergency Medicine.

"When emergency department staff needs to know the weight of children for purposes of emergency resuscitation, parents generally offer the most accurate estimates," said lead author Kelly D. Young, MD, MS, of the Harbor-UCLA Medical Center in Los Angeles. "Length-based methods of measurement came in second. We still have trouble getting accurate estimates for children from populations with high obesity rates and high malnourishment rates, regardless of which method is used."

How accurate were the parents’ estimations? The study found that 70% to 80% of parents and legal guardians estimated children's weight within a 10% margin higher or lower than the child's actual weight.

For the review, 80 studies met inclusion criteria with predominant methods: parent or healthcare worker weight estimation, age-based formulas, and length-based estimation without – for example Broselow Tape — or with adjustment for body habitus — for example, Pediatric Advanced Weight-Prediction in the Emergency Room (PAWPER) tape or the Mercy method.

“Length-based methods outperformed age-based formulae, and both tended to underestimate the weight of children from populations with high obesity rates and overestimate the weight of children from populations with high malnourishment rates,” according to study authors. “Healthcare worker estimation was not accurate.”

The study points out that age-based formulas and length-based methods without body-type adjustment tended to predict ideal, not actual, body weight.

"No reported method is truly ideal," Young added in an American College of Emergency Physicians press release. "Parental estimation, while pretty accurate, may not be available at the time of resuscitation or parents may be distraught. Parent estimation and length-based methods with adjustment for a child's body type are the most accurate methods for predicting children's total actual body weight. But then it gets complicated because some resuscitation drugs are best dosed based on ideal body weight."