Noninvasive Blood Pressure Monitoring Issued April 2010

Noninvasive Blood Pressure Monitoring 2 Expected Practice  Measure blood pressure (BP) in the upper arm using the oscillatory or auscultatory method.  Unable to measure in the upper arm  Measure in forearm  Consider thigh or calf measurement

Expected Practice  Use appropriate size BP cuff Noninvasive Blood Pressure Monitoring 3

4 Expected Practice  Measure baseline BP bilaterally Noninvasive Blood Pressure Monitoring 4

Expected Practice  Position patient  the appropriate reference level for NIBP is the heart. Noninvasive Blood Pressure Monitoring 5

Patient Position — Seated  Patient should be seated with back and arms supported, feet on floor, and legs uncrossed with upper arm at heart level (phlebostatic axis: 4th intercostal space, halfway between the anterior and posterior diameter of the chest) (Figure 1) Figure 1 Noninvasive Blood Pressure Monitoring 6

Patient Position — Supine  position patient supine or  with head of bed at a comfortable level and with upper arm supported at heart level. Figure 2Figure 3 Noninvasive Blood Pressure Monitoring 7

Expected Practice  The patient and the caregiver should remain quiet throughout the procedure of taking a BP Noninvasive Blood Pressure Monitoring 8

Scope and Impact of the Problem  Blood pressure is measured in virtually all patients  Accurate measurement of blood pressure is essential to guide management decisions  Inaccuracy may lead to over or under- treatment of the patient’s condition Noninvasive Blood Pressure Monitoring 9

Supporting Evidence  Use oscillatory devices that meet the Association for the Advancement of Medical Instrumentation standards (mean difference + 5mm Hg and standard deviation < 8mm Hg) when compared to auscultatory method12 and the appropriate size cuff. Noninvasive Blood Pressure Monitoring 10

Supporting Evidence  Stiffness of the arteries, influences amplitude of the oscillations and may cause underestimation MAP  Accuracy of the automated device may also be limited in patients with hypertension, hypotension, and cardiac dysrhythmia.  Some studies showed difference 10mm Hg for some individuals.  Vasopressors show no significant effect on difference Noninvasive Blood Pressure Monitoring 11

Supporting Evidence  Forearm and upper arm BP's are not interchangeable  Select the proper cuff size and positioning of forearm at heart level Noninvasive Blood Pressure Monitoring 12

Supporting Evidence Cuff Position  Forearm – position the cuff midway between the elbow and wrist  Thigh – position the cuff over the lower third of thigh ( lower edge of cuff approximately 2 to 3cm above popliteal fossa) Noninvasive Blood Pressure Monitoring 13

Supporting Evidence  With all BP measurements select the proper size cuff  Calf BP measurements- place the patient in the supine position. Place the patient in the prone position for thigh BP measurements. If the patient cannot be place prone, position the patient supine with knee slightly bent.  Thigh pressures are normally higher than upper arm pressures  Calf pressures are not interchangeable with upper arm pressures Noninvasive Blood Pressure Monitoring 14

Supporting Evidence  Calf BP measurement (referred to as an ankle BP) Korotkoff’s sounds are auscultated over either the dorsalis pedis or posterior tibial artery in calf BP or the popliteal artery in thigh BP  In adults, calf BP's should be used only if the upper arm is not accessible Noninvasive Blood Pressure Monitoring 15

Supporting Evidence  Reasons an extremity may not be suitable for BP measurement.  BP cuffs should not be used on extremities with a deep vein thrombosis, grafts, ischemic changes, arteriovenous fistula, or arteriovenous graft  BP cuffs should not be applied over a PICC or midline catheter site  In extremities with peripheral IV while an infusion is running or any trauma/incision.  Patients that have had mastectomy or lumpectomy  do not use the involved arm(s) for BP's if there is lymphedema. Noninvasive Blood Pressure Monitoring 16

Supporting Evidence  Appropriate cuff size necessary for accurate measurement of BP in all extremities  Cuff too narrow = overestimation of BP  Cuff too wide = underestimation BP.  Cuff is too small = falsely high reading may result  Cuff is too large = falsely low reading may result  Use a cuff with a bladder capable of going around 80% of the arm Noninvasive Blood Pressure Monitoring 17

Supporting Evidence  Patients with aortic dissection, congenital heart disease, coarctation of the aorta, peripheral vascular disease, and unilateral neurological and musculoskeletal abnormalities may demonstrate a difference in inter-arm BP  20% - 40% of individuals without the above conditions may have a measurable difference of 10 to 20mm Hg BP between left and right arms  One study showed higher mean differences in systolic and diastolic BP in older participants  When there is a consistent interarm difference, use the arm with higher pressure. Noninvasive Blood Pressure Monitoring 18

Supporting Evidence  Body position and arm position influence the measurement of BP  With patient supine and arm placed at heart level the systolic BP is approximately 8mm Hg higher than in the sitting position  Studies show if arm is below heart level BP readings will be higher, conversely, if the arm is above heart level BP readings will be lower Noninvasive Blood Pressure Monitoring 19

Supporting Evidence  Systolic and diastolic BP's in hypertensive and normotensive patients increase with talking Noninvasive Blood Pressure Monitoring 20

Actions for Nursing Practice  Ensure that your facility has written procedures BP measurement  Ensure proper size cuffs are readily available  Ensure devices meet appropriate standards  Provide routine training healthcare providers in BP measurement Noninvasive Blood Pressure Monitoring 21

For more information or further assistance, please contact a clinical practice specialist with the AACN Practice Resource Network. Need More Information? Noninvasive Blood Pressure Monitoring 22