Blood pressure (OSCE)
Taking a Blood Pressure
General
edit- 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
edit- cuff size
- bladder width > 40 % of arm circumference
- length > 80% of arm circumference
Positioning
edit- Level: devices and columns at eye level, patient’s arm held at heart level
Placement
edit- lower edge of cuff ~ 3 cm above elbow crease
- bladder centered over brachial artery (palpate medial to biceps tendon)
Performance
edit- 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
edit- 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
edit(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