Vital Signs of the Times
How do you know if your child is sick? Do you use a thermometer or any of the myriad new devices for measuring vital signs? Until the 20th century, most American mothers had none of these at their disposal, even thermometers. Instead, mothers used the oldest tools available: their eyes and their hands. Mom’s knew when their child looked “off”.
Even before the rectal thermometer arrived in most American households, mothers used the “kiss test” to tell if their child had a fever. They would kiss the child’s forehead: if the child’s skin felt hot on her lips, there was a fever. That was the extent of Dr. Mom’s diagnostic toolbox, but it worked extraordinarily well.
Today, parents can buy tools online that permit measuring vital signs that had previously only been available to doctors in hospitals. The question is: do these instruments let you know if a child is sick or not? Is more information better than less? How do today’s electronics match up to mom’s kiss test? To answer these questions, there are some important facts regarding pediatric vital signs.
How does her heart rate?
Heart rate is one of the easiest vital signs to measure. All one needs are fingers and a timing device. But being able to measure heart rate requires knowing what a normal heart rate is! Heart rates vary with the age of the child. The younger, the faster.
A sleeping newborn may have a heart rate of 120 beats per minute and be perfectly healthy. You or I, on the other hand, probably need to be exercising intensely to achieve a heart rate that high. If a child (of any age) appears well and is feeding well, the heart rate is not all that important. It may only be meaningful if the child is sick. It’s important for parents to know that a child’s heart rate will be faster than normal when she has a fever, sometimes as much as 10–20 beats per minute faster.
There are some rare conditions in which a child’s heart rate can be very fast, as much as 200–220 beats per minute (bpm). These conditions, including supraventricular tachycardia (SVT), are caused by rare abnormalities in the electrical wiring of the child’s heart. The heart rate shoots up to 200 bpm suddenly and without warning. Sometimes the child is aware of the jump, and may even feel ill. SVT requires immediate medical attention.
On the other end of the spectrum is low heart rate. Some people, even children, have naturally low heart rates. However, if a child does not have a naturally slow heart rate, a drop in her heart rate to 60 bpm or less may signal a severe illness. Call your pediatrician if you have any questions at all about normal heart rates.
A Hot Topic
Of all the vital signs, none more misunderstood than body temperature, particularly fever. Just as with heart rate, it is important for parents to understand some important facts about fever.
First, it is important for parents to know that the height of fever does not correlate with the severity of a child’s illness. A child may be happily playing in the yard with a temperature of 102ºF (38ºC). A playing child is probably not seriously ill. On the other hand, imagine a child sleeping in bed motionless. She wakes up only if you shake her, but falls asleep instantly when you stop shaking her (this is a graphic description of what doctors call “lethargy”). You take the child’s temperature and it is 98.6ºF (37ºC). “Phew”, you say, “Thank goodness she’s not sick!”. Wrong. This child is very sick. She needs medical attention immediately. The point of this example is that fever, taken out of context of the child’s appearance, means very little. You must take activity and general appearance into account when assessing a child’s health.
The exception is a baby less than 8 weeks old. If these babies have temperatures of 102ºF (38ºC) or higher, you should seek medical attention immediately. For fully-vaccinated babies over 6 months of age, the kiss test is just as good as the thermometer. For babies between 2 and 6 months, with all their shots, consult a pediatrician for any questions about fever.
Fever, in the context of an illness, is a mechanism humans use to help fight off foreign invaders, like viruses and bacteria. Fever is actually helpful: higher body temperatures activate the mechanisms that allow the child to rid herself of the microbe faster.
That is not to say that one should not give fever reducers to a sick child. To the contrary, you should! But it’s important to know that one should give fever reducers for one reason, and one reason only: to make the child feel better. You don’t need to bring down a body temperature for its own sake. It’s not necessary to give a febrile child a tepid bath, unless doing so is soothing to the child. And one should never, ever, bathe a febrile child in rubbing alcohol. This is a dangerous practice that can result in alcohol poisoning.
Mother knows best
It’s true that we have many great devices today to measure heart rates and take children’s temperatures. But at the end of the day, mother’s hands and eyes are the most powerful tools ever invented for determining if a child is sick or not. The Kiddo wants help, alerting a caretaker that their child might need help earlier than one might recongize on their own. However, in the end: Mother truly does know best.
