Vital SignsBlood pressure Blood Pressure Arterial blood pressure

Vital Signs/Blood pressure

Blood Pressure • Arterial blood pressure is a measure of pressure exerted by the blood as flows through the arteries. (measured by mm. Hg. ) • 120/80 mm. Hg (adults)

BP normal limits Two Types of pressure measures: • Systolic pressure: as result of ventricles contraction. • Diastolic pressure: when the ventricles are at rest. • Pulse Pressure: difference between the diastolic and systolic pressures (normal is 40)

Determinants of BP • Cardiac output • Peripheral vascular resistance • Blood volume • Blood viscosity (Hct. > 60 -65%)

Factors Affecting BP • • • Age (elasticity of the arteries) Exercise (wait 20 -30 min) Stress Race : African American males over 35 years have higher BP than European males at the same age. Gender: after puberty, females have lower BP than males due to hormonal variations. Medications Obesity: predispose to hypertension. Diurnal variations: BP lowest early in the morning, then rises during the day Disease process 5

Assessing BP • Indirect § Sphygmomanometer and stethoscope § Electronic Sphygmomanometer § Doppler ultrasound • Direct • (Invasive Monitoring) Arterial lines Sites: • Upper arm (brachial artery) • Radial ? ? ? • Thigh (popliteal artery) 6

Hypertension • Cannot be diagnosed unless an elevated blood pressure is found when measured twice at different times. Types: 2. Primary: unknown cause 1. Secondary: known cause • Associated factors include: arteriosclerosis, smoking, obesity, alcohol, lack of physical activity, high blood cholesterol and stress. • Rx. : treatment of secondary causes, life style changes and monitoring. 7

8

Hypotension • Is a BP that is below normal, that is systolic between 85 and 110 mm. Hg in an adult whose normal pressure is higher than this. • Orthostatic hypotension: is a BP that falls when the client sits or stands. • Causes: drugs, bleeding, severe burn and dehydration • Management : supine position 2 -3 min. , V/s, prevent falls, Rx of the cause. 9

Oxygen Saturation • Pulse Oximeter: noninvasive device that estimates a client’s arterial blood oxygen saturation (Sa. O 2). • Detects hypoxemia before clinical signs and symptoms • Normal Sa. O 2 is 95%-100% • Sa. O 2 below 70% is life threatening. 10

11