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By Karla Gale

WESTPORT, CT (Reuters Health) – In children with burns over 40% of their body surface area, beta-blockade with propranolol decreases resting energy expenditure and muscle catabolism, according to a report in The New England Journal of Medicine for October 25.

"The catabolic state persists for up to a year after the time of injury, and children of this age may even stop growing," Dr. David N. Herndon pointed out in an interview with Reuters Health. "Reversal of the catabolic response during acute hospitalization can allow them to grow normally, be stronger and return to regular activities more quickly."

Dr. Herndon and associates, of Shriners Hospitals for Children at the University of Texas, in Galveston, randomly assigned 13 children to oral propranolol for at least 2 weeks, while 12 children were relegated to normal treatment.

Following the second surgery for autografting, propranolol was started at 0.33 mg/kg every 4 hours. The dose was adjusted until the patient's heart rate was decreased 20% from baseline, to a final average dose of 1.05 mg/kg every 4 hours.

In the control group, resting energy expenditure increased by a mean of 140 kcal/day and oxygen consumption by 25 mL/min between baseline and 2 weeks. In contrast, patients in the propranolol group had significant decreases, by 422 kcal/day and 56 mL/minute, respectively (p = 0.001 and 0.002).

Over the same period of time, control patients lost about 9% of their fat-free mass, compared with a loss of about 1% in the propranolol group (p = 0.003).

Dr. Herndon also recommends propranolol for use in patients under other types of physiologic stress, such as those who have experienced a long bone fracture, septicemia, or treatment in an intensive care unit.

"The key to using it safely is to decrease the heart rate towards normal," he noted, "but to monitor the heart rate so as not to overshoot. You don't want the patient to become hypotensive."

He stressed that propranolol should not be used in asthmatics or in people subject to bronchospasm. Under those circumstances, metoprolol, which does not activate asthma, would be a more appropriate agent, he said.

In future research, Dr. Herndon's team plans to test the results of beginning propranolol treatment earlier after injury and for more extended periods.

Dr. Robert L. Sheridan, of Shriners Burns Hospital in Boston, notes in an editorial that children with serious inhalation injury and children requiring mechanical ventilation were not included in the study, so "the use of propranolol in such children should therefore be considered separately."

He also recommends that propranolol "should be used cautiously and only in an intensive care unit."

N Engl J Med 2001;345:1223-1229.