A nurse is obtaining vital signs from a 2-month-old infant. The infant’s heart rate is 190/min and his temperature is 40° C (104° F). The father asks the nurse why the infant’s heart is beating so fast. Which of the following responses by the nurse is appropriate?
A.
“This is within the expected range for your baby.”
B.
“The fever is causing an increase in your baby’s heart rate.”
C.
“As your baby begins to fall asleep. his heart rate will decrease.”
D.
“Your baby’s heart is beating fast in an attempt to cool down his body.”
The Correct answer and Explanation is:
The correct answer is B. “The fever is causing an increase in your baby’s heart rate.”
Explanation:
When a nurse obtains vital signs from a 2-month-old infant and finds that the heart rate is 190 beats per minute (bpm) and the temperature is 40°C (104°F), it is important to understand the physiological relationship between fever and heart rate. In infants and young children, fever is a common cause of tachycardia, which is an abnormally fast heart rate.
Understanding the Connection:
- Fever and Heart Rate: Fever causes the body’s metabolism to increase as it tries to fight off an infection. This metabolic increase requires more oxygen and nutrients, which the heart compensates for by increasing its rate to deliver more blood to tissues and organs. This physiological response is known as the “fever-tachycardia” relationship, where for every 1°C rise in body temperature, the heart rate can increase by about 10 to 20 bpm.
- Normal Heart Rate Ranges: For a 2-month-old infant, the normal resting heart rate typically ranges from 100 to 160 bpm. A heart rate of 190 bpm, therefore, is elevated and indicative of tachycardia, which can be attributed to the high fever.
Analyzing the Other Options:
- Option A: Stating that the heart rate is within the expected range is incorrect because 190 bpm is above the normal range for a 2-month-old infant at rest, especially without considering the context of fever.
- Option C: Suggesting that the heart rate will decrease as the baby falls asleep might be true in some cases, but it does not directly address the father’s concern or explain the current elevated heart rate, which is primarily due to the fever.
- Option D: The statement that the heart is beating fast to cool down the body is incorrect. While the body has mechanisms like sweating and vasodilation to cool down, an increased heart rate due to fever is not directly linked to body cooling.
Conclusion: The most appropriate response is to explain that the infant’s elevated heart rate is a normal physiological response to the fever. This helps reassure the parent by providing a clear and accurate explanation, fostering trust and understanding in the nurse-patient-family relationship. It also emphasizes the importance of monitoring and managing the fever to help bring the heart rate back to a normal range.