High blood pressure is notoriously difficult to detect in children. And the consequences of undiagnosed hypertension can be severe.
Sustained high blood pressure can lead to target end-organ disease, meaning long term effects on:
- the kidney, e.g. renal insufficiency and ultimately end stage kidney disease
- the heart, e.g. left ventricular hypertrophy and ultimately congestive heart failure
In children, “the difference between normal and abnormal blood pressure can be small, depending on factors like age, height and weight,” says Sarah de Ferranti, MD, director of the Preventive Cardiology Program at Boston Children’s Hospital.
A reading of 120/75 would be:
- Stage two hypertension in a two-year old
- Stage one hypertension in a seven-year old
- Pre-hypertension in an 11-year old
- Either normal or pre-hypertension in a 17-year old
- A normal reading for an adult
“Not all kids with high blood pressure are overweight, but all overweight kids are at risk for high blood pressure,” adds de Ferranti.
If a blood pressure reading seems elevated, she advises, “It’s important to have a ‘high index of suspicion.’”
Ask yourself the following questions:
- Am I using the right size cuff?
- Is the arm positioned correctly?
- Is the child in the midst of an illness or taking a medication that might raise blood pressure?
- Have I considered how my method of measuring blood pressure might skew results? An automated device reads blood pressure higher than measuring it manually, so the way of measuring blood pressure in the clinic is with a manual cuff.
- Is it possible the high number could be related to anxiety, nervousness or recent exercise?
Improving and simplifying the guidelines
“I think we can do better when it comes to correct measurement,” says de Ferranti.
“For example, we could have a pop-up message in the electronic medical record (EMR) that automatically notifies you when a reading is too high based on the patient’s age, gender and height percentile.”
But not every pediatric practice has an EMR, or a high-quality EMR, so improving the guideline is also important. The standard table from the published in the 2004 is the way to identify high blood pressure. Most pediatricians find it highly specific and a bit cumbersome to use; it includes 476 possible values and requires you know the child’s height percentile.
“A new and improved table could be simpler, so you could quickly tell if a particular measurement warrants attention,” says de Ferranti. “David Kaelber, MD, who spent a training year here at Boston Children’s, designed one that was published in Pediatrics. Dr. Corinna Rea, MD, in primary care here at Boston Children’s is also working on an algorithm that would help incorporate the guidelines on early work-up and measurement into practice.” de Ferranti and Rea are part of a multidisciplinary workgroup within the American Academy of Pediatrics (AAP) that is developing new guidelines, expected to be published within the next two years.
So: What do you do when you detect high blood pressure?
First, says de Ferranti, confirm the blood pressure is high on three separate occasions.
Callout: An ambulatory blood pressure monitor can help a lot with distinguishing white coat or reactive blood pressure from sustained hypertension.
Second, evaluate for potential causes to rule out secondary hypertension.
“For kids over 10, it’s usually related to diet and activity level,” she says, “but some kids have a secondary cause, such as a kidney or vascular problem. These are more difficult to treat and warrant referral to a sub-specialist in nephrology or cardiology.
Whenever a reading suggests stage 2 hypertension, REFER,” she says. “And schedule a follow-up visit sooner rather than later, ideally within the next week.”
If a reading is in the pre-hypertension range, de Ferranti emphasizes:
- Maintaining a heart healthy diet
- Decreasing weight
- Increasing physical activity
- Checking blood pressure and monitoring lifestyle every three to six months
“Pediatricians are already pretty great at these lifestyle recommendations,” she notes. “But one thing I’d add is, take a look at the child’s salt intake,” she adds. “It can be found in surprising places! Bread often has a lot of sodium, and of course bread is often paired with meat and cheese, which also have a fair amount of sodium. Other sneaky culprits are foods in a box, like crackers. The goal for a healthy child should be less than 2500 mg of sodium – 1500 mg per day is a reasonable target for someone with hypertension.
If the patient is suffering from headaches, chest pain, and/or vision changes, arrange for a rapid referral. Extremely high blood pressure readings particularly if accompanied by symptoms always warrant an ER visit.”
Is the problem really getting worse? Why?
de Ferranti says her practice has definitely seen more patients with hypertension in the past five years, and over the past ten years, as understanding of the obesity epidemic has grown, there’s been more evaluation of high blood pressure.
“We don’t really know the contributions of responsibilities and stress and pressure on kids to this but I wouldn’t be surprised if there is a relationship. It’s quite a decent hypothesis,” says de Ferranti.
Other things that can lead to high blood pressure are:
- Maternal hypertension during pregnancy
- Medications (such as medications for ADHD)
- Kidney problems
- Frequent urinary tract infections
de Ferranti says it’s hard to know yet exactly whether hypertension is on the rise or if we are just paying closer attention to it. In any case, identifying and treating early signs of hypertension is an extremely important part of pediatric primary care today.
Learn more about the Preventative Cardiology Clinic at Boston Children’s Hospital.