MAUI, HAWAII — Taking blood pressure measurements as part of routine checkups for very young children can help reveal underlying problems early, said Dr. Carl M. Grushkin, head of the division of nephrology at Childrens Hospital Los Angeles.
New data showing a disturbing upturn in high blood pressure rates among children aged 8–17 years shore up efforts to diagnose the problem earlier. After decades of a downward trend from 1963 to 1988, prevalence rates of pre-high blood pressure and high blood pressure increased 2.3% and 1%, respectively, between 1988 and 1999, according to surveys conducted by the National Center for Health Statistics (Circulation 2007;116:1392–400).
Yet, “the [American Academy of Pediatrics], in its recommendations, still says that you don't have to take blood pressures in kids until they're 3,” Dr. Grushkin said, speaking at a meeting sponsored by the University Childrens Medical Group and the American Academy of Pediatrics. “I think that's absolutely insane.”
“In kids up to 10 years of age who have severe hypertension, essentially you will always find a cause,” and “almost always it's something that can be fixed,” Dr. Grushkin observed at the meeting, also sponsored by the California Chapter 2 of the AAP. He categorized severe hypertension as being “frequently symptomatic, with systolic, or especially diastolic, blood pressure 15–20 mm Hg greater than 95th percentile for age and height.”
To highlight the usefulness of blood pressure measurement in the very young, Dr. Grushkin referred to a case in which a girl had a systolic blood pressure of 90 mm Hg by palpation at her routine checkup at age 1 year and a blood pressure measurement of 140/100 mm Hg at her checkup at age 2.
The little girl's history was negative, she was not on medication, and her height and weight were at the 50th percentile at both her 1- and 2-year checkups. “The femoral pulses were fine,” Dr. Grushkin recalled, “and the rest of the physical exam was normal,” as were the results of a series of laboratory tests.
Having been able to rule out most possible underlying causes of the child's hypertension, Dr. Grushkin narrowed his focus to the girl's kidneys. He knew that at least one kidney had to be functioning normally, since there was no renal insufficiency, but was concerned about a possible congenital abnormality or a renovascular problem.
Following a normal ultrasound upon admission to the hospital, the child was started on medication to control the blood pressure; 36 hours later she had a renal angiogram, which showed that while the main renal arteries were normal, the upper polar vessel to one of the kidneys was stenotic.
Deciding that the child was a little small to be a candidate for an operation, and that it was not possible to put in a stent, Dr. Grushkin and the primary care physician kept the child on therapy for 3 years, after which time they brought her back to the hospital and corrected the stenosis. “She came out of surgery and didn't need any more antihypertensives,” he said. “She was in the hospital 4 days, went home, and has been fine ever since.”
Dr. Grushkin said although many physicians do measure blood pressure in older children routinely, the very young are often overlooked.
Noting concerns among physicians about how to take blood-pressure measurements in very young patients, he offered recommendations from his own practice.
The “old standard way” of measuring blood pressure with a sphygmomanometer has, over the years, moved more and more toward involving automated inflating devices, he observed. “Those work fairly well for kids probably 4 and above, as long as with the little kids you tell them what to expect: that it's going to make a noise, that it's going to squeeze the arm, and it may hurt just a tiny bit,” said Dr. Grushkin, also professor of clinical pediatrics at the University of Southern California, Los Angeles.
“They don't work particularly well for very young infants, for the same reason. There's a noise, the cuff is pumped up well above the systolic blood pressure, it's pumped up very quickly, and it hurts.”
With babies in his clinic, he said, he always does a palpable systolic blood pressure. “We simply let the mother or the dad hold the baby, put the appropriate size cuff on the baby—usually on the right arm—and put a pacifier in the baby's mouth.”
Then put a finger on the brachial artery, and slowly pump the cuff up. “Where the pulse disappears is the systolic blood pressure. You then release the pressure, and let it come down. You feel it again, and you're done,” Dr. Grushkin said. “It takes about 30 seconds to do, and it's reproducible.”