Chapter 3: Vital Signs — Assessment and Normal Ranges

Vital signs are the most fundamental clinical measurements in nursing practice. They provide rapid, objective data about a patient’s physiological status and are often the first indicators of deterioration or recovery.

The Six Vital Signs

The traditional four vital signs — temperature, pulse, respiration, and blood pressure — have been expanded to include oxygen saturation (SpO₂) and pain, which is now widely recognized as the sixth vital sign.

Normal Ranges by Age Group

Vital Sign	Infant (0–1 yr)	Child (6–12 yr)	Adult	Older Adult
Temperature (°C)	36.5–37.5	36.5–37.5	36.1–37.2	35.8–37.0
Pulse (bpm)	120–160	70–110	60–100	60–100
Respiration (breaths/min)	30–60	18–30	12–20	12–18
Systolic BP (mmHg)	60–90	90–110	90–120	90–140
SpO₂ (%)	95–100	95–100	95–100	95–100

Assessment Techniques

Temperature can be measured orally, rectally, axillary, tympanically, or temporally. Rectal temperature is most accurate in adults and infants but is contraindicated after rectal surgery. Fever is defined as ≥38.0°C (100.4°F).

Pulse is assessed for rate, rhythm, and quality. Radial pulse is the standard site in adults; brachial or apical pulse is used in infants and children under 2. Apical pulse (auscultated at the 5th intercostal space, midclavicular line) is required before administering cardiac medications.

Respiration should be counted without alerting the patient (which can alter the breathing pattern). Count for a full 60 seconds in patients with irregular respirations.

Blood pressure is best measured with the patient seated, arm at heart level, after 5 minutes of rest. Use the correct cuff size: a cuff too small gives a falsely high reading; too large gives a falsely low reading.

SpO₂ via pulse oximetry is affected by poor perfusion, nail polish, motion, and carbon monoxide poisoning (gives falsely high reading in CO poisoning).

Pain: The Sixth Vital Sign

Pain assessment uses validated scales:

• Numeric Rating Scale (NRS): 0–10, for adults who can self-report
• Wong-Baker FACES: for children ages 3+ and cognitively impaired patients
• FLACC: behavioral scale for infants and non-verbal patients
• CPOT: Critical-Care Pain Observation Tool for ventilated ICU patients

Key Checklist

• State the normal adult range for all six vital signs and identify one factor that can cause a falsely abnormal reading for each
• Describe the correct technique for measuring blood pressure, including common errors and their effects
• Select the appropriate pain assessment scale for three different patient populations (adult, toddler, ventilated ICU patient)