VITAL SIGNS BLOOD PRESSURE (BP)

WHAT IS BP? The pressure exerted on the arterial walls by the pumping action of the heart

FACTORS THAT CREATE YOUR BP Heart rate Force of heart’s contractions Circulating blood volume Elasticity of the blood vessels

MEASUREMENT OF BP Systolic - the higher # - the pressure in the blood vessel when the heart is contracting Diastolic – the lower # - the pressure in the blood vessel when the heart is at rest Pulse pressure – the difference between the systolic & diastolic BP

NEW ADULT HYPERTENSION GUIDELINES Normal BP = < 120/80 Pre-hypertension = 120-139/80-89 Stage I-Hypertension = 140-159/90-99 Stage II-Hypertension = >160 systolic and > 100 diastolic

REMEMBER YOU Need to know usual BP range of pt to be able to determine if problem exists Major changes in BP from usual range usually indicate problem

BP VARIATIONS BP can vary from minute to minute as the heart adjusts to demands & responses of the body & mind

FACTORS AFFECTING BP Age – BP  in young &  in elderly Anxiety, fear & stress -  BP Race – BP more common in certain races Meds – can  or  BP (decongestants  BP)

Factors Affecting BP

FACTORS AFFECTING BP

Changes in Vital Signs Occurring with Aging Systolic and diastolic blood pressure may rise with hardening of the arteries Prolonged hypertension can cause permanent damage to the brain, kidneys, heart, retina of the eyes, & is a major cause of strokes (CVA)

ORTHOSTATIC (POSTURAL) HYPOTENSION Drop in BP when change in position from lying or sitting to standing CHECK BP IN SITTING & STANDING POSITIONS Instruct pt to get up slowly Common in elderly due to  elasticity of blood vessels with age. Blood pools in lower extremities. Elastic stockings may lessen the problem. Also common in people on certain meds!

OTHER CAUSES OF HYPOTENSION MEDICATION Loss of blood volume Extreme hypotension = SHOCK S&S of shock =  BP,  P, dizziness, blurred vision, apprehension, cold, clammy skin Loss of blood volume – from hemorrhage, vomiting, diarrhea, burns, or MI (heart attack)

EQUIPMENT TO MEASURE BP Stethoscope – used to hear (auscultate) the sounds made in the artery by the beats of the heart Diaphragm- used to hear high-pitched  sounds Bell- used to hear low-pitched  sounds Sphygmomanometer – occludes the artery & then slowly allows blood flow through it

SPHYGMOMANOMETER Cuff size – must fit pt limb (pedi, adult, large, X-large) If use incorrect size = incorrect reading False high reading if cuff too small

CORRECT SIZE CUFF: WIDTH IS 20% LARGER THAN DIAMETER OF ARM & INFLATABLE BLADDER SHOULD GO AROUND AT LEAST ¾ OF THE ARM

PARTS OF THE SPHYGMOMANOMETER Gauge (measures BP) Tubing from gauge to cuff Cuff –with bladder inside (wrapped around arm or leg) Control bulb (inflates & deflates cuff)

TYPES OF MANOMETERS Mercury gauge – most accurate Aneroid gauge Automated BP machines (dinamap)- no stethoscope required

How to Accurately measure Blood Pressure Nurses usually use the brachial artery for assessing BP However, many factors can interfere with accurate BP measurement e.g. –An IV in an arm, a patient who has had a mastectomy, edema, AV fistula, a cast, or a wound dressing If the arm cannot be used, you can use the forearm, thigh or calf

KAROTKOFF SOUNDS The sounds heard with the stethoscope while measuring BP Phase I – systolic BP reading-1st sound heard Phase II-soft, swishing sound Phase III-rhythmic tapping sound Phase IV –Softer and fading-diastolic BP in children & some adults Phase V –Silence- diastolic BP reading

Guidelines for Measuring BP Have pt rest for 5 min. before measure Use brachial artery, support arm on a surface @ level of heart Check condition of equipment, position manometer so you can read it @ eye level, gauge indicator should be at 0 when cuff deflated

Guidelines for Measuring BP Use correct size cuff Place stethoscope directly on skin Palpate brachial artery before taking BP, inflate cuff & note the level at which the pulse disappears. Deflate cuff. Place diaphragm of stethoscope firmly over brachial artery

Guidelines for Measuring BP Inflate cuff 30 mm Hg. above where the pulse disappeared. Slowly deflate cuff (2 mm. per second) and listen for 1st sound (systolic pressure). Continue listening until sound disappears or if sound continues until 0, note reading when sound becomes muffled (diastolic pressure).

REMEMBER Never reinflate cuff when deflating cuff Always record reading as soon as possible ALWAYS MEASURE BP & PULSE TOGETHER