Vital Signs, Weights & Critical Value Reporting
Key Takeaways
- Normal adult vital sign ranges are temperature 97.0-99.0 degrees F, pulse 60-100 bpm, respirations 12-20 breaths/min, blood pressure under 120/80 mmHg, and SpO2 95-100%.
- Orthostatic hypotension is confirmed by a systolic BP drop of 20 mmHg or more, or a diastolic drop of 10 mmHg or more, within 1-3 minutes of standing.
- Under the ACC/AHA guideline, Stage 2 hypertension is defined as a systolic reading of 140 mmHg or higher or a diastolic reading of 90 mmHg or higher.
- An SpO2 reading below 90% must be reported to the nurse immediately as a critical value.
- The apical pulse, auscultated at the heart's apex, is the required measurement site for infants and patients with irregular heart rhythms.
Vital Signs: The Body's Baseline
Vital signs — temperature, pulse, respiration, blood pressure, and pulse oximetry — are the fastest way to detect that a patient's physiological status is changing. A PCT/A who can measure these accurately, knows the normal ranges, and recognizes a critical value is protecting the patient from a missed emergency.
Normal Adult Ranges
| Vital Sign | Normal Adult Range | Notes |
|---|---|---|
| Temperature | 97.0-99.0 degrees F (36.1-37.2 degrees C) | Oral is most common; rectal runs about 1 degree F higher, axillary about 1 degree F lower |
| Pulse | 60-100 beats/min | Radial site most common; apical required for infants or irregular rhythms |
| Respirations | 12-20 breaths/min | Count for a full 60 seconds without the patient's awareness |
| Blood pressure | Less than 120/80 mmHg | See the staging table below |
| SpO2 (pulse oximetry) | 95-100% | Below 90% requires immediate reporting |
Blood Pressure Staging (ACC/AHA)
| Category | Systolic (mmHg) | Diastolic (mmHg) |
|---|---|---|
| Normal | Less than 120 | and less than 80 |
| Elevated | 120-129 | and less than 80 |
| Stage 1 Hypertension | 130-139 | or 80-89 |
| Stage 2 Hypertension | 140 or higher | or 90 or higher |
| Hypertensive Crisis | Higher than 180 | and/or higher than 120 |
Measurement Methods and Sites
Temperature can be measured orally (under the tongue), rectally (most accurate, often used for infants), axillary (least accurate, used when other routes are contraindicated), tympanic (ear), or temporal (forehead scan). Pulse is most often palpated at the radial artery (wrist); other common sites include brachial, carotid, femoral, popliteal, dorsalis pedis, and apical (auscultated at the heart's apex, required for infants and patients with irregular rhythms). Count for a full minute whenever the rhythm is irregular. Respirations are best counted without telling the patient, since awareness of being watched can change breathing rate; note the rate, depth, and rhythm together. Blood pressure is measured with a properly sized cuff at heart level, typically over the brachial artery, after the patient has rested quietly for at least 5 minutes with legs uncrossed and back supported. A cuff that is too small will falsely elevate the reading, while a cuff that is too large will falsely lower it — selecting the correct cuff size for the patient's arm circumference is essential for an accurate result.
Pulse and Respiration Quality
Beyond the numeric rate, a PCT documents quality and rhythm. Pulse strength is described with terms such as bounding (strong, easily felt), normal, thready/weak (difficult to palpate, may signal shock or dehydration), or absent; rhythm is documented as regular or irregular. Respiration quality includes tachypnea (rate above 20/min), bradypnea (rate below 12/min), dyspnea (labored or difficult breathing), and Cheyne-Stokes breathing (a pattern of gradually increasing then decreasing depth with periods of apnea), which is often seen in end-of-life or severe neurological patients. Reporting quality alongside the number gives the nurse a fuller clinical picture than the rate alone.
Orthostatic Blood Pressure
Orthostatic (postural) vital signs detect blood pressure drops caused by position changes. Blood pressure and pulse are measured after the patient has been supine for 5 minutes, then again within 1-3 minutes of sitting or standing. A drop of 20 mmHg or more in systolic pressure, a drop of 10 mmHg or more in diastolic pressure, or a pulse increase of 30 beats/min or more, is a positive result and signals a fall risk — the patient should be supported and returned to bed, and the finding reported to the nurse.
Weights and Scale Types
Accurate weight tracking guides medication dosing and fluid status monitoring. Standing scales are used for ambulatory patients; chair scales accommodate patients who can transfer but not stand steadily; bed scales (built into specialty beds or used with a sling/lift) are used for patients who cannot be safely moved. Weigh patients at the same time of day, in similar clothing, on the same scale whenever possible for a valid trend, and always zero and calibrate the scale before use. Because many medication doses are calculated in kilograms, always confirm which unit — pounds or kilograms — the facility's scale and chart use, and never guess or convert in your head under time pressure.
Point-of-Care Critical Values Requiring Immediate Report
Certain findings can never simply be charted and left for later — they must be reported to the nurse immediately: SpO2 below 90%, a new fever above 100.4 degrees F (38 degrees C), systolic BP below 90 or above 180 mmHg, heart rate below 50 or above 120 bpm, respiratory rate below 10 or above 24 breaths/min, and any point-of-care glucose reading below 70 mg/dL or above 400 mg/dL. Recognizing these thresholds — and escalating without delay — is one of the highest-yield safety competencies tested on the CPCT/A exam, because a delayed report on any one of these values can allow a treatable problem to become a life-threatening one. When any of these values is discovered, the PCT should stay with the patient, recheck the reading if time allows, and communicate the exact number to the nurse rather than a vague description — 'his oxygen is 84%' is far more actionable than 'he doesn't look right.'
Which blood pressure reading falls into the Stage 1 Hypertension category under the ACC/AHA guideline?
During an orthostatic blood pressure check, a patient's systolic pressure drops from 128 mmHg supine to 104 mmHg within 2 minutes of standing. How should this be interpreted?