Dynamic Maneuvers and Their Diagnostic Value
Vt Challenge:
A transient increase in Vt from 6 mL/kg to 8 mL/kg for one minute, with a PPV increase ≥3.5%, suggests preload responsiveness.
Benefits include simplicity and minimal equipment requirements.
Threshold variability and false positives in ACP remain concerns.
End-Expiratory Occlusion Test:
A 15-second interruption of ventilation at end-expiration increases preload, and a rise in cardiac output ≥5% confirms preload responsiveness.
Late systolic reversal with blunted systolic flow indicating high RA pressure with big A wave makes it due to either tricuspid stenosis or complete heart block