Blood pressure (OSCE)

Taking a Blood Pressure

General

 * No:
 * smoking or caffeine x 30 mins
 * constrictive clothing


 * Yes:
 * rest for ≥ 5 minutes
 * breathing normal and relaxed


 * During recording: no talking and patient’s legs uncrossed

Equipment

 * cuff size
 * bladder width > 40 % of arm circumference
 * length > 80% of arm circumference

Positioning

 * Level: devices and columns at eye level, patient’s arm held at heart level

Placement

 * lower edge of cuff ~ 3 cm above elbow crease
 * bladder centered over brachial artery (palpate medial to biceps tendon)

Performance

 * palpate radial pulse (note arrythmias)
 * inflate cuff to ~ 30 mm Hg above palpable pulse
 * drop the pressure by 2 mm Hg / second (prolonged filling will lead to venous congestion, making the sounds harder to hear)
 * repeat after ≥ 2 minutes of standing to assess for orthostatic hypotension (drop in 20/10)


 * for all patients on the first visit, take at least 2 readings separated by 2 minutes
 * if first 2 readings differ by > 5 mm Hg, another reading is indicated
 * Elevated readings should be confirmed on 3 readings

Pitfalls

 * anxiety, pain
 * arrhythmias
 * wrong cuff size (too small overestimates, too large underestimates)
 * Isolated office hypertension ('white coat' hypertension) (up to 25%)
 * exercise

JNC-7 Classification
(criteria for adults > 17 and not taking antihypertensives)


 * Optimal
 * Normal	        		< 120 SBP   and  < 80 DBP
 * Prehypertension               120-139 SBP or   80-89 DBP
 * Hypertension Stage 1		140-159 SBP or  90-99 DBP
 * Hypertension Stage 2		>or=160       or   >or=100