Question

The most recent advance in non-invasive cardiac output monitoring is the use of:

• A. PA catheter
• B. Thermodilution technique
• C. Echocardiography
• D. Electrical impedance cardiograph technology

Hint:

Rule out anything that needs a catheter first; among the non-invasive options, pick the newest bedside technology.

Answer 1

The Correct Option is D

Step 1: Sort the options into invasive and non-invasive methods.
The pulmonary artery (PA) catheter, also called the Swan-Ganz catheter, is passed through a central vein into the pulmonary artery. This is an invasive procedure, so option (A) is ruled out straight away.

Step 2: Look at thermodilution.
Thermodilution measures cardiac output by injecting cold saline through the same PA catheter and recording the temperature change downstream. Since it needs that same catheter, it is also invasive, not the answer we want.

Step 3: Look at echocardiography.
Echocardiography is non-invasive and can estimate cardiac output using Doppler measurement of blood flow across a valve, but it is an older, well established imaging technique, not the newer bedside monitor being asked about here.

Step 4: Look at electrical impedance (bioimpedance) cardiography.
This technique places skin electrodes on the neck and chest and measures the change in electrical resistance (impedance) of the thorax as blood volume shifts with each heartbeat. It needs no catheter and no probe insertion, and it gives a continuous, beat to beat cardiac output reading. At the time this exam was written, this was the newest addition to non-invasive cardiac output monitoring, and bioimpedance based monitors are still used today, later refined into bioreactance devices.

Final Answer:
The most recent non-invasive advance among these options is electrical impedance cardiography.
\[ \boxed{\text{Electrical impedance cardiograph technology}} \]