Assessing Blood Pressure

These skills are related to: Vital Signs

Assessing respirations is done to:

• Establish baseline measurement of arterial blood pressure for subsequent evaluation.
• Determine the client’s hemodynamic status (e.g., cardiac output: stroke volume of the heart and blood vessel resistance)
• Identify and monitor changes in blood pressure resulting from a disease process or medical therapy

Phase	Nursing Activities
Assessment	Assess for signs and symptoms of hypertension (e.g., headache, ringing in the ears, flushing of face, nosebleeds, fatigue), of hypotension (e.g., tachycardia, dizziness, mental confusion, restlessness, cool and clammy skin, pale or cyanotic skin) Determine any factors that could change blood pressure such as recent activity, emotional stress, pain, and time the client last smoked or ingested caffeine. In cases of activity or caffeine intake, the nurse must wait for 30 minutes in order to obtain a reliable reading.
Planning	Assign: blood pressure measurement may be assigned to AP. The nurse interprets abnormal blood pressure readings and determines appropriate responses. Equipment: stethoscope or DUS, blood pressure cuff of the appropriate size, and sphymomanometer.
Implementation	Ensure that the equipment is intact and functioning properly. Check for leaks in the tubing between the cuff and the sphygmomanometer. Calibrate as necessary. Ensure that it has been at least 30 minutes since the last ingestion of caffeine or smoking. Prior to performing the procedure, the nurse must introduce themselves and verify the client’s identity using agency protocol. Explanation of the nurse’s purpose, the procedure, and how the patient will participate. Perform hand hygiene and observe appropriate infection prevention procedures. Provide client privacy. Position the client appropriately. The adult client should be sitting unless otherwise specified. Both feet should be flat on the floor. Crossed legs will elevate readings. The elbow should be slightly flexed with the palm of the hand facing up and the arm supported at heart level. Variations from this position should be noted upon documentation if performed. Expose the upper arm. Wrap the deflated cuff evenly around the upper arm. Locate the brachial artery, and apply the center of the bladder directly over the artery. In an adult, this is approximately 2.5 cm (1 in.) above the antecubital space. If this is the initial examination, perform a preliminary palpatory determination of systolic pressure, which will be used as basis for estimated systolic pressure. Palpate the brachial artery and pump up the cuff until it is no longer felt. Note this pressure. Position the stethoscope appropriately. Make sure the stethoscope is clean and the earpieces are worn correctly (tilted slightly forward).The bell-shaped diaphragm is used because blood pressure sounds are low-frequency, but the American Heart Association states both the bell and diaphragm can be used. The amplifier is placed on the skin, not over cloth. Auscultate the client’s blood pressure. Pump up the cuff until the sphygmomanometer reads 30 mmHg above the point the brachial pulse disappeared, then release the valve carefully so that the pressure decreases at a rate of 20 to 30 mm Hg per second. As the manometer falls, take note of the pressure at the time Korotkoff sounds 1, 4, and 5 are heard. Sounds 2 and 3 are not clinically significant. Once phase 5 is heard, the cuff is deflated rapidly and completely. After 1 to 2 minutes, repeat the above steps to confirm the accuracy of the reading. If significant difference (>5 mmHg) is observed, further measurements may be required and averaged. If this is the client’s initial assessment, it is repeated on the client’s arm. A difference of 10 mmHg between the arms is common in hypertensive and diabetic clients, and should be evaluated further. Remove the cuff, and wipe with an approved disinfectant. Uncleaned cuffs may become significantly contaminated. If the cuff is disposable, dispose according to institution policy. Document and report pertinent assessment data according to agency policy. Record two pressures in the form “130/80” where “130” is the systolic (phase 1) and “80” is the diastolic (phase 5) pressure. Record three pressures in the form for phase 1, phase 4, and phase 5, “130/90/0”, if sounds are audible even after complete deflation. Indicate the extremity used for assessment with RA or RL for right arm or right leg and LA or LL for left arm or left leg.
Evaluation	Relate blood pressure to other vital signs, to baseline data, and to health status. If findings are significant different from previous values without obvious reasons, consider possible causes of error. Any significant changes are reported. Abnormal findings that persist over time are also reported: Systolic blood pressure above 140 mmHg Diastolic blood pressure above 90 mmHg Systolic blood pressure below 100 mmHg Inter-arm differences of greater than 10 mmHg

Variations

1. Palpation Method: if a stethoscope is not usable, palpate the radial or brachial pulse sites as the cuff pressure is released. The manometer reading at the point where the pulse reappears is an estimate of systolic value. The manometer reading at the point where the whiplike vibration appears is an estimate of the diastolic pressure.
2. Thigh Blood Pressure:
   • The patient is positioned prone. If contraindicated, the client is positioned supine with the knee slightly flexed.
   • Expose the thigh, taking care not to expose the client unduly.
   • Locate the popliteal artery.
   • Wrap the cuff evenly around the midthigh with the compression bladder over the posterior aspect of the thigh and the bottom edge above the knee.
   • If this is the client’s initial examination, perform a preliminary palpatory determination of systolic pressure by palpating the popliteal artery.
   • In adults, the systolic pressure in the popliteal artery is usually 20 to 30 mmHg higher than that in the brachial artery; the diastolic pressure is usually the same.
3. Electronic Indirect Blood Pressure Monitoring Device: an automated machine can be given a preset for wait periods, repeated assessments, and averaged assessments while the client is resting quietly, seated in a chair, and alone in the room. This can also be left in place for many hours. The cuff should be removed periodically to check skin condition.