BLOOD PRESSURE

Auscultatory Method
Oscillometric Method

BLOOD PRESSURE CAN BE MEASURED:

Auscultatory Method (Manually)

This involves listening to arterial sounds (named ‘Korotkoff sounds’, after Nicolai Korotkoff, a Russian surgeon who first described the auscultation method of measuring BP in 1905)

Oscillometric Method (Automatically)

This detects variations in pressure oscillations due to arterial wall movement.

Blood Pressure

The pressure of blood against the walls of the main arteries

Systolic blood pressure

peak blood pressure in the artery following ventricular systole (contraction)

Diastolic blood pressure

level to which the arterial blood pressure falls during ventricular diastole (relaxation)

Hypertension

high blood pressure: consistently >140/90mmHg

Hypotension

low blood pressure: typically a systolic reading of <90mmHg

≥65 years

In healthy patients, there is usually little difference between lying and standing BP readings. However, a significant fall in BP (≥20mmHg) can occur with a change of position, particularly in patients aged? and those with diabetes

Postural hypotension

- Sometimes termed orthostatic hypotension, is when an abnormally low BP occurs when a person suddenly assumes a standing position, typically inducing dizziness and syncope.
- The condition is more common in older people and its prevalence increases with age.

Diuretics
Antihypertensives

Postural Hypotension can also be caused by a number of medications including?

- Dizziness
- Syncope
- Fall or Changing in Position

Postural hypotension can present with a clinical picture of?

• Drop in systolic BP of ≥20mmHg (with or without symptoms);

• Drop in BP to <90mmHg on standing, even if the drop is <20mmHg (with or without symptoms);

• Drop in diastolic BP of 10mmHg with symptoms (but, clinically, much less significant than a drop in systolic BP).

A diagnosis of postural hypotension is indicated when there is a:

• All patients aged ≥65 years;

• Patients aged 50-64 years who are judged by a clinician to be at higher risk of a fall due to an underlying condition.

The following groups of inpatients should be considered as at risk of falling in hospital and receive an individualised, multifactorial assessment, including lying and standing BP:

• Patient not being rested and relaxed when BP is measured;
  Defective equipment – for example, leaky tubing or a faulty valve;

• Too-rapid deflation of the cuff;

• Use of incorrectly sized cuff;

• Cuff not being on a level with the heart;

• Poor technique;

• ‘Digit preference’ – rounding a reading up to the nearest 5mmHg or 10mmHg;

• Observer bias – for example, expecting a young patient’s BP to be normal;

• Irregular pulse (as can occur with, for example, AF, bradycardia, muscle tremors, a weak pulse or profound shock) – in some automated devices, this can lead to inaccurate measurement

There are numerous causes of errors in BP measurements, including:

- Aneroid
- Mercury
- Digital

Types of Sphygmomanometer

Chestpiece

- Head of the stethoscope
- has a connected stem, diaphragm, and/or bell.
- Is placed on the patient's skin and is responsible for conducting sound.

Diaphragm

- Is the large circular end of the chest piece.
- Allows listening to an area of the patient’s body and picks up higher frequency sounds.

Bell

- Is the smaller circular end of the chest piece.
- Focuses on a narrower range of listens for lower-frequency sounds that may not easily be detected by the diaphragm.
- Is most effective at transmitting lower frequency sounds, while the diaphragm of the stethoscope is most effective at transmitting higher frequency sounds.

Stem

- Is basically the metal / steel part of the stethoscope that connects the tubing of the stethoscope to the chest piece.
- On stethoscopes with two-sided chest pieces, the stem of the device allows users to switch between the diaphragm and bell by turning the chest piece.
- By rotating this, the diaphragm is open to the acoustic path of relating to the sound of an organ/ body.

Stethoschope Tubing

- The soft flexible line of the stethoscope.
- Maintain and transfer the frequency or sound level, that is captured by the diaphragm or bell and sent it to the ear tubes.
- Connects to the metal/steel ear tubes.

Headset

- Is the combined components of the upper half of the stethoscope which include the ear tubes, tension springs, and Earpieces.
- Has two ear tubes.

Earpieces

- Consist of small round tips on the ends of the ear tubes that fit into the ears.
- Allow sound to flow efficiently into the ear canal.

Systolic: Less than 120
Diastolic : Less than 80

Normal Blood Pressure

Systolic: 120-129
Diastolic: Less than 80

Elevated Blood Pressure

Systolic: 130-139
Diastolic: 80-89

High Blood Pressure (Hypertension Stage 1)

Systolic: 140 or Higher
Diastolic: 90 or Higher

High Blood Pressure (Hypertension Stage 2)

Systolic: Higher than 180
Diastolic: Higher than 120

Hypertensive Crisis (Hypertension Stage 2)