Parents of children with asthma are often concerned about their child’s health, especially when symptoms worsen. Monitoring vital signs like heart rate can indicate a child’s well-being and the severity of a respiratory event, helping parents recognize when medical attention is needed.
Normal Heart Rate Ranges for Children
A child’s normal resting heart rate varies significantly by age, generally decreasing as they get older. For newborns (birth to 4 weeks), the typical range is 100-205 beats per minute (bpm). Infants from 4 weeks to 1 year usually have a resting heart rate between 100-180 bpm. Toddlers aged 1 to 3 years typically fall within 98-140 bpm, while preschoolers (3 to 5 years) range from 80-140 bpm.
School-aged children (5 to 12 years) generally have a heart rate between 70-120 bpm, and adolescents (12-18 years) share a similar range with adults at 60-100 bpm.
To accurately measure a child’s resting heart rate at home, ensure the child is calm and has been resting for at least five minutes. You can gently place two fingers (not your thumb) on the inside of their wrist, below the thumb, or on the side of their neck, just below the jaw. Once a pulse is felt, count the beats for 30 seconds and then multiply that number by two to get the beats per minute. A pulse oximeter, if available, can also measure heart rate and oxygen levels by clipping onto a finger.
How Asthma Affects Heart Rate
During an asthma episode, a child’s heart rate can increase due to the body’s physiological response to reduced oxygen intake and the increased effort required for breathing. When airways narrow, the lungs work harder to move air, which can lead to lower oxygen levels in the blood. This triggers the body’s autonomic nervous system to increase heart rate and breathing rate in an attempt to compensate and deliver more oxygen to tissues. This compensatory mechanism is known as tachycardia, a common sign during an acute asthma exacerbation.
Certain asthma medications, particularly bronchodilators like albuterol, can also cause a temporary increase in heart rate. Albuterol works by relaxing the smooth muscles in the airways to widen them, but it can also activate beta2 receptors in the heart, leading to a rapid heart rate or palpitations as a side effect. This is a common and expected side effect of these medications, and it usually subsides as the medication’s effects wear off.
Recognizing a Dangerous Heart Rate
A heart rate becomes concerning when it is sustained and significantly elevated, especially during an asthma attack, indicating the body is struggling. For children aged 2 to 5 years, a pulse consistently greater than 140 beats per minute during an asthma exacerbation may be considered severe. For children older than 5 years, a heart rate exceeding 125 beats per minute can signal a severe attack. These heart rate thresholds are important indicators, but they should always be evaluated alongside other symptoms of respiratory distress.
When to Seek Emergency Care
Immediate medical attention is necessary if a child’s heart rate remains dangerously high despite the use of rescue medication. If quick-relief medications, such as albuterol, are not effective, or if symptoms worsen after 15-20 minutes, emergency care should be sought. Signs such as persistent severe breathing difficulty, wheezing that does not improve, or a lasting cough unresponsive to inhaled medicine are reasons to seek help.
Other critical indicators for emergency care include changes in the child’s color, such as bluish or gray lips and fingernails, which suggest inadequate oxygen. Visible retractions, where the areas below or between the ribs or in the neck pull in significantly with each breath, also warrant immediate medical evaluation. If a child has trouble talking, cannot speak in full sentences, or becomes unusually tired, quiet, or unresponsive, these are serious red flags. Parents should always adhere to their child’s individualized Asthma Action Plan and communicate all observed symptoms to medical professionals.