Written by Chris Thom
Spoon Feed
This study found that POCUS with power doppler accurately measured blood pressure as compared to intraarterial line values.
Sometimes the cuff just doesn’t read
This was a prospective study of ICU patients who had an existing intraarterial line placed. Investigators performed a POCUS blood pressure measurement by using a standard BP cuff on the upper arm while imaging the brachial artery with color power doppler. The BP cuff was inflated in standard fashion, then slowly deflated while the brachial artery was imaged. At the point where the cuff deflated and color power doppler flow was identified, the pressure reading on the BP cuff and the arterial line pressure were both recorded.
There were 50 patients enrolled. The arterial line systolic pressure and POCUS color power doppler pressures were highly correlated with a Pearsons correlation coefficient of 0.96.
How will this change my practice?
I’ve used this technique before, but it is helpful that there is now data to support the practice. It has been very useful in cases where we couldn’t get the automated BP cuff to read or when there is difficulty with auscultation while using the manual cuff. It can also come in handy with LVAD patients due to the difficulty in both automated BP cuffs and manual BP cuff auscultation. You are essentially visualizing the blood flow as it is first able to pass through the deflating BP cuff, which then provides the systolic BP. I’ve also used this as an easier way to perform ABI measurements. Instead of having to wander around with the handheld doppler stick, I can place the doppler box over the relevant artery and wait for the color signal to appear.
POCUS Pro-Tips and Clips
You certainly don’t need to be a POCUS expert to pull this off. Just identify your brachial artery on ultrasound, apply the doppler box, and then inflate your manual BP cuff on the upper arm. You’ll see the doppler flow disappear as the cuff pressure increases. While deflating the cuff, watch for the first sign of color signal, which will be your systolic blood pressure. The authors here make note that color power doppler is the setting of choice, as it is much less angle dependent than traditional color doppler. This means that you don’t have to worry as much about ultrasound beam angle placement as it relates to the blood flow trajectory. Most of our POCUS machines have this setting.
Source
Measurement of Systolic Blood Pressure Using POCUS With Color Doppler Compared to with an Intraarterial Line. POCUS J. 2025 Nov 17;10(2):30-33. doi: 10.24908/pocusj.v10i02.19281. PMID: 41322169; PMCID: PMC12658582.
