Which cardiac monitoring method provides the most accurate non-invasive measurement of cardiac output in the operating theatre?

• A Transthoracic echocardiography (TTE)
• B Oesophageal Doppler monitoring of descending aortic blood velocity
• C Bioimpedance cardiography
• D Transoesophageal echocardiography (TOE/TEE) ✓

Explanation

Transoesophageal echocardiography (TOE) provides real-time direct visualisation of cardiac chambers, valves, filling status, regional wall motion abnormalities, and calculation of cardiac output (stroke volume × heart rate via Doppler). It is the most accurate intraoperative haemodynamic monitoring tool and the standard for cardiac surgery, major vascular surgery, and haemodynamic instability. TTE has poor windows in anaesthetised, ventilated, supine patients. Oesophageal Doppler measures descending aortic flow (estimates 70% of cardiac output) — less accurate but simpler and less invasive. Bioimpedance is unreliable intraoperatively.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.