Postoperative volume balance: does stroke volume increase in Trendelenburg's position?

Area of Science:

• Cardiovascular Physiology
• Critical Care Medicine
• Surgical Recovery

Background:

• Healthy individuals typically do not show increased stroke volume (SV) or cardiac output (CO) with central blood volume expansion.
• Post-surgical patients' fluid responsiveness is crucial for optimal recovery and preventing complications.

Purpose of the Study:

• To investigate if Trendelenburg position can predict fluid responsiveness in post-surgical patients.
• To assess the impact of head-down tilt on cardiovascular variables in a post-operative cohort.

Main Methods:

• Non-invasive cardiovascular monitoring using Modelflow in 85 post-surgical patients.
• Patients were placed in Trendelenburg position to assess changes in stroke volume (SV) and cardiac output (CO).
• Fluid challenge with Ringer's lactate was administered to a subset of patients exhibiting a significant SV increase.

Main Results:

• Trendelenburg position significantly increased SV and CO (P<0.05) in the patient cohort.
• Heart rate and mean arterial pressure remained unaffected during head-down tilt.
• A fluid challenge further increased SV and CO in patients who responded to Trendelenburg positioning.

Conclusions:

• Head-down tilt in Trendelenburg position can serve as a reliable method to predict fluid responsiveness in post-surgical patients.
• This non-invasive technique aids in identifying patients who would benefit from intravenous fluid administration.
• The findings suggest a practical approach for fluid management in the perioperative setting.