A Randomised Controlled Study Comparing Pulse Pressure Variation (PPV) and Pleth Variability Index (PVI) for...

Area of Science:

• Anesthesiology
• Critical Care Medicine
• Neurosurgery

Background:

• Perioperative fluid management remains challenging, especially in neurosurgery due to diuretic use.
• Dynamic parameters for fluid responsiveness, like GDFT, are increasingly used but their efficacy in neurosurgery is not well-established.
• Intracranial space occupying lesions (ICSOLs) present unique fluid management considerations.

Purpose of the Study:

• To compare the efficacy of Pleth Variability Index (PVI) versus pulse pressure variation (PPV) in guiding goal-directed fluid therapy (GDFT) during neurosurgery for supratentorial ICSOLs.
• To evaluate the impact of PVI- and PPV-guided GDFT on postoperative serum lactate levels as a marker of tissue perfusion.
• To assess other postoperative outcomes including fluid administration, blood loss, CCU stay, and complications.

Main Methods:

• A randomized controlled trial involving 74 patients undergoing neurosurgery for supratentorial ICSOLs.
• Patients were randomized into either PVI-guided or PPV-guided GDFT groups.
• Fluid management involved a baseline infusion and additional boluses triggered by PVI (>15%) or PPV (>13%) thresholds.

Main Results:

• No significant difference was observed in postoperative lactate levels between the PVI and PPV groups (P=0.18).
• Mean total fluid administered, blood loss, CCU stay, and episodes of emesis or hypotension also showed no significant differences between the groups.
• Both PVI and PPV demonstrated low sensitivity and specificity in guiding GDFT, with areas under the curve of 0.423 for PVI and 0.577 for PPV.

Conclusions:

• In neurosurgery patients with supratentorial ICSOLs, PVI-guided GDFT is comparable to PPV-guided GDFT in terms of tissue perfusion and postoperative complications.
• Both PVI and PPV have limitations in accurately guiding GDFT in this specific patient population.
• Further research may be needed to refine dynamic parameters for fluid management in complex neurosurgical cases.