Complete Guide to CNA Vital Signs: Temperature, Pulse, Respiration, & BP

import DownloadCTA from "../../../../components/DownloadCTA"; // ... inside component ...

Why Vital Signs Matter

As a Certified Nursing Assistant (CNA), taking vital signs is one of your most frequent and critical responsibilities. You are the "eyes and ears" of the medical team. Accurate measurements can save lives; inaccurate ones can lead to dangerous mistreatment.

Vital signs (VS) provide a snapshot of a patient's basic body functions. The four primary vitals you must master are:

1. Body Temperature (T)
2. Pulse Rate (P)
3. Respiration Rate (R)
4. Blood Pressure (BP)

Exam Tip: You will likely be tested on at least one of these during your state skills exam.

---

1. Body Temperature (T)

Temperature measures the heat in the body. It basically tells us if the body is fighting an infection.

Normal Range:

• Oral: 97.6°F - 99.6°F (36.5°C - 37.5°C)
• Note: Rectal temps are typically 1°F higher; Axillary (armpit) temps are 1°F lower.

How to Measure (Oral - Digital Thermometer):

1. Wash Hands & Gloving: Standard precautions.
2. Verify: Ask if the patient has smoked, eaten, or drank anything hot/cold in the last 15-20 minutes. If yes, wait.
3. Position: Place the probe under the tongue in the "heat pocket" (sublingual pocket).
4. Hold: Ask patient to close lips tight around the probe (not teeth!).
5. Record: Remove when it beeps. Discard sheath. Record exactly.

---

2. Pulse Rate (P)

Your pulse is the wave of blood created by the heart pumping. We usually measure it at the Radial Artery (wrist).

Normal Range:

• Adults: 60 - 100 beats per minute (BPM).
• Tachycardia: > 100 BPM
• Bradycardia: < 60 BPM

How to Measure:

1. Locate: Place your fingertips (Index & Middle, NEVER thumb) on the thumb-side of the patient's inner wrist.
2. Count: Count the beats for one full minute (for exam purposes). In real life, 30 seconds x 2 is common, but on the test, measure for 60 seconds to be safe.
3. Rhythm: Note if it is "Regular" or "Irregular".

---

3. Respiration Rate (R)

One respiration consists of one inspiration (breath in) and one expiration (breath out).

Normal Range:

• Adults: 12 - 20 breaths per minute.

The "Secret" Technique:

• If a patient knows you are counting their breaths, they will unconsciously change their breathing.
• Trick: After counting the pulse, keep your fingers on their wrist but shift your gaze to their chest. Count breaths for another 60 seconds without telling them you stopped counting the pulse.

---

4. Blood Pressure (BP)

Blood pressure is the force of blood against artery walls. It is written as Systolic / Diastolic.

• Systolic (Top Number): The pressure when the heart beats.
• Diastolic (Bottom Number): The pressure when the heart rests.

Normal Range:

• Systolic: 90 - 119 mmHg
• Diastolic: 60 - 79 mmHg
• Hypertension: 130/80 or higher (new guidelines).

How to Measure (Manual Cuff):

1. Position: Arm at heart level, palm up.
2. Cuff: Apply cuff 1-2 inches above elbow. Align the "Artery" arrow with the brachial artery.
3. Inflate: Find the estimated systolic, add 30 mmHg.
4. Listen: Place stethoscope diaphragm over the brachial artery. Release air slowly (2-3 mmHg per second).
5. First Sound (Korotkoff I): This is your Systolic reading.
6. Sound Disappears (Korotkoff V): This is your Diastolic reading.

---

Common Vital Sign Mistakes on the Exam

1. Using your thumb for pulse: Your thumb has its own pulse. You will count your own heart rate instead of the patient's!
2. Cuff placement: Placing the BP cuff over clothing or too loosely will give an error.
3. Rounding: Do not round numbers. If the needle lands on 122, write 122, not 120.
4. Forgetting "Wait Time": If a patient just drank ice water, you MUST wait 15-20 minutes before taking an oral temp.

Practice Quiz

Ready to test your knowledge? Take the Vital Signs Practice Test