TIDAL VOLUME CHALLENGE EFFECT ON PULSE OXIMETRY PLETHYSMOGRAPHY WAVE VARIATION TO PREDICT FLUID RESPONSIVENESS IN SEPTIC SHOCK PATIENTS

Abstract

Introduction:Sepsis is a critical condition caused by a dysregulated immune response to infection, often leading to organ dysfunction and high mortality, especially in intensive care units. Septic shock, its most severe form, involves circulatory collapse and poor tissue perfusion. Fluid resuscitation is vital to restore hemodynamics, but excessive fluids may cause harm. Traditional static measures like central venous pressure (CVP) fail to reliably predict fluid responsiveness. Dynamic indices such as pulse pressure variation (PPV) are more accurate but require invasive monitoring. Pulse oximetry plethysmography waveform variation (POPV) offers a non-invasive alternative, reflecting respiratory-induced changes in ventricular preload. Its accuracy improves with a tidal volume challenge (TVC), a maneuver temporarily increasing tidal volume to enhance cardiopulmonary interactions. Combining POPV with TVC allows accurate, bedside, non-invasive prediction of fluid responsiveness, even under lung-protective ventilation strategies. This approach aligns with precision-guided care, minimizes fluid overload risk, and is feasible in both resource-rich and limited settings.Aim of the Work:The aim of this work is to assess tidal volume challenge effect on pulse oximetry plethysmography wave variation as a non-invasive method to predict fluid responsiveness in septic shock mechanically ventilated patients.