Systolic Blood Pressure and Pulse / Heart Rate

Systolic Blood Pressure

Although an elevated blood pressure (hypertension) is an important risk factor for cardiovascular disease, it is a low or falling systolic blood pressure (hypotension) that is most significant in assessing the severity of acute illness. Hypotension may indicate circulatory compromise due to sepsis or volume depletion, as well as many other significant causes. Blood pressure is measured using millimetres of mercury (mmHg). It is important to note that some patients may have a naturally low systolic blood pressure (i.e., <100mmHg) and this should be confirmed by reviewing any baseline blood pressure measurements.

Please note;

• A systolic blood pressure <90mmHg may be a sign of severe sepsis, fluid loss or cardiac shock and will require the patient to be further assessed.
• Falling blood pressure should be regarded as a late sign of deterioration.
• In cases of very low blood pressure, the use of an electronic blood pressure monitor may not be accurate, and a manual sphygmomanometer should be used to obtain accurate measurements. Manual sphygmomanometers must be made available and clinicians should be trained and competent in using them.

Scoring to be applied to systolic blood pressure (mmHg) in accordance with NEWS is as follows;

Systolic Blood Pressure (mmHg)	>220	111 – 219	101 – 110	91 -100	<90
Score	3	0	1	2	3

Pulse / Heart Rate

The measurement of pulse / heart rate is an important indicator of a patient’s clinical condition, and is measured in beats per minute (bpm). A high heart rate (tachycardia) may be indicative of circulatory compromise due to sepsis or volume depletion, cardiac failure, pyrexia, or pain / general distress. A low heart rate (bradycardia) may be normal with physical conditioning or as a consequence of some medications (i.e., beta-blockers). However, it may also be an important indicator of hypothermia, central nervous system depression, hypothyroidism or heart block.

The pulse is a reflection of the heart rate and is frequently measured via the oxygen saturation probe on a pulse-oximeter or via an electronic blood pressure monitor. This presents 3 significant issues;

1. the pulse measured and recorded may not reflect the true heart rate
2. pulse properties cannot be determined, i.e., volume and regularity
3. clinicians may not develop the necessary skills in assessing pulses and their properties.

In order to address these issues;

1. a manual pulse should be taken at first assessment in order to assess pulse properties (i.e., rate, rhythm, strength)
2. where measured electronically, a pulse rate of >90 bpm or <50 bpm should initiate the clinician to re-assess the patient’s pulse manually. The rate and regularity should also be assessed and recorded.

Scoring to be applied to pulse / heart rate (bpm) in accordance with NEWS is as follows;

Pulse / Heart Rate (bpm)	<40	41 – 50	51 – 90	91 – 110	111 – 130	>131
Score	3	1	0	1	2	3