Vital Signs in Infants

Normal Vital Signs

The American Academy of Pediatrics recommends normal vital signs for a two-month-old infant, including a heart rate of 121-179 beats per minute, respiratory rate of 30-60 breaths per minute, axillary temperature of 36.5-37.4°C, and normal oxygen saturation above 95% 1
Heart rates as low as 70 beats per minute are acceptable while sleeping quietly without signs of circulatory compromise, according to the American Academy of Pediatrics 1
Pulse oximetry screening is recommended for all newborns before discharge, as stated by the American Academy of Pediatrics 1

Normal heart rate ranges for infants are:
Bradycardia is defined as a heart rate below 91 bpm in the first week and below 107 bpm in the first month, as stated by Praxis Medical Insights 3
Tachycardia is defined as a heart rate above 166 bpm in the first week and above 179 bpm in the first month, as stated by Praxis Medical Insights 3
Heart rate <60 bpm with signs of poor perfusion requires immediate intervention, according to Praxis Medical Insights 3

The QRS axis in full-term neonates is 55-200°, decreasing to ≤160° by 1 month, according to the European Society of Cardiology 2
The QRS duration is narrow (<80 ms) in newborns and infants, as per the European Society of Cardiology 2
The mean QTc on the 4th day of life is 400±20 ms, with an upper normal limit of 440 ms, as established by the European Society of Cardiology 2
T waves are normally variable in the first week; after 1 week, they are negative in lead V1 and positive in V5, according to the European Society of Cardiology 2

Blood pressure parameters are not routinely measured in healthy two-month-old infants unless there is a specific clinical concern, and when measured, blood pressure interpretation should follow age-appropriate guidelines, as stated by the American College of Critical Care Medicine 4