Skip to Main Content

Chapter 3: Hemodynamic Monitoring

A 62-year-old man with a history of paraplegia and a chronic indwelling suprapubic catheter is admitted into the ICU due to hemodynamic instability. He is fluid resuscitated, cultures are obtained, and he is started on empiric antimicrobial therapy. Norepinephrine is initiated for his persistently low blood pressure and an arterial line is placed for blood pressure monitoring. The nurse calls you over after she notices that the automated systolic cuff pressures are significantly higher than the arterial line pressures. Which of the following statements could explain the discrepancy?

A. With lower blood pressure (systolic below 95), automated blood pressure measurements are often falsely higher than intra-arterial systolic pressure measurements.

B. The resistance in the arterial line system set up is too high (overdamped), leading to an underestimation of systemic arterial pressure.

C. The automated cuff is currently placed on the leg and is usually 10% to 20% percent higher than that in the brachial artery.

D. All of the above.

D. All of the above

There are numerous reasons for a discrepancy in systolic blood pressure measurements between automated noninvasive measurements and intra-arterial measurements. Recent data has suggested that at lower blood pressures, a noninvasively measured systolic blood pressure will usually be higher than intra-arterial sampling without significant deviation in the mean arterial pressures (choice A). If the resistance in the arterial line is too high, there will be less mechanical displacement and subsequent lowering of the electrical signal, ultimately leading to a diminished blood pressure reading (choice B). Finally, studies suggest that in normal adults, systolic blood pressure readings are often higher in the legs than in the arms (choice C).

A 62-year-old man with a history of paraplegia and a chronic indwelling suprapubic catheter is admitted into the ICU due to hemodynamic instability. He is fluid resuscitated, cultures are obtained, and he is started on empiric antimicrobial therapy. Norepinephrine is initiated for his persistently low blood pressure and an arterial line is placed for blood pressure monitoring. The nurse calls you over after she notices that the automated systolic cuff pressures are significantly higher than the arterial line pressures. Which of the following statements could explain the discrepancy? You examine the arterial line tracing and note a good waveform. What would your next best step be?

A. Compare the mean arterial pressure obtained from both the noninvasive measurement and the invasive measurement.

B. Ask the nurse to use the systolic measurement obtained from the noninvasive measurement and not from the arterial line.

C. Ask the nurse ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.