Aim: Recording of Blood Pressure
References:
1. Guyton, A. C., & Hall, J. E. (2016). Textbook of Medical Physiology. Elsevier.
2. American Heart Association (AHA) Guidelines on Blood Pressure Measurement.
3. Whelton, P. K., et al. (2018). Hypertension Guidelines. Journal of the American College of Cardiology.
Objective:
To measure and record the blood pressure of a subject using a sphygmomanometer and understand the physiological significance of systolic and diastolic pressure.
Principle:
Blood pressure (BP) is the force exerted by circulating blood on the walls of blood vessels. It is measured in millimeters of mercury (mmHg) and consists of two readings:
- Systolic Pressure: The pressure during ventricular contraction.
- Diastolic Pressure: The pressure during ventricular relaxation.
Requirements:
Sphygmomanometer (Mercury/ Aneroid/ Digital), Stethoscope (for auscultatory method), Notebook and pen for recording, Subject (volunteer)
Methodology:
1. Auscultatory Method (Using Mercury or Aneroid Sphygmomanometer)
1. Ensure the subject is seated comfortably with the arm resting at heart level.
2. Wrap the BP cuff around the upper arm, about 2-3 cm above the elbow.
3. Place the diaphragm of the stethoscope over the brachial artery (inside of the elbow).
4. Inflate the cuff to about 20-30 mmHg above the expected systolic pressure (usually 180 mmHg).
5. Slowly deflate the cuff at a rate of 2-3 mmHg per second while listening through the stethoscope.
6. Note the pressure at which the first Korotkoff sound is heard (systolic pressure).
7. Continue deflating and note the pressure at which the sound disappears (diastolic pressure).
8. Record the systolic and diastolic BP as Systolic/Diastolic mmHg.
2. Digital Blood Pressure Measurement
1. Place the cuff on the subject’s upper arm as per the device instructions.
2. Press the start button and let the device inflate and deflate automatically.
3. The digital display will show the systolic and diastolic BP along with the pulse rate.
4. Record the values.
Normal Blood Pressure Values:
| Category | Systolic (mmHg) | Diastolic (mmHg) |
| Normal | <120 | <80 |
| Elevated | 120-129 | <80 |
| Hypertension Stage 1 | 130-139 | 80-89 |
| Hypertension Stage 2 | ≥140 | ≥90 |
Sample Result Table:
| Subject ID | Method Used | Systolic (mmHg) | Diastolic (mmHg) | Interpretation |
| 101 | Auscultatory | 118 | 76 | Normal |
| 102 | Digital | 135 | 85 | Hypertension Stage 1 |
| 103 | Auscultatory | 142 | 95 | Hypertension Stage 2 |
| 104 | Digital | 122 | 78 | Normal |
| 105 | Auscultatory | 128 | 82 | Elevated |
Precautions:
- The subject should be relaxed for at least 5 minutes before measurement.
- Ensure the cuff is neither too tight nor too loose.
- Measure on the same arm each time for consistency.
- Avoid talking or moving during the measurement.
- Take multiple readings at least 1 minute apart for accuracy.
Clinical Significance:
Hypertension: High BP can indicate cardiovascular risk, kidney disease, or stress-related conditions.
Hypotension: Low BP may be due to dehydration, blood loss, or endocrine disorders.
Regular monitoring is essential for the management of hypertensive and cardiovascular conditions.
Happy Learning,
pharmaacademias.com Team