PPV and fluid responsiveness

Q: Recent literature has shown that pulse pressure variation (PPV) is a better indicator of fluid responsiveness than central venous pressure (CVP). But applicability of PPV  is limited. Which conditions should be met to obtain reliable PPV?


Answer:

1. Patient should be mechanically ventilated

2. Patient should not be spontaneously triggering the ventilator

3. Tidal Volume (TV) on ventilator should be  ≥8 mL/kg of ideal body weight

4. Patient should be in normal sinus rhythm

5. Patient has no major alternations to chest wall compliance (making open chest patients ineligible) 

PPV of 12 -15 percent is usually associated with volume responsiveness.

References/further reading:

1. Pinsky MR. Functional haemodynamic monitoring. Curr Opin Crit Care 2014; 20:288.

2. Marik PE, Cavallazzi R, Vasu T, et al. Dynamic changes in arterial waveform derived variables and fluid responsiveness in mechanically ventilated patients: a systematic review of the literature. Crit Care Med. 2009;37(9):2642-7

3. Michard F, Teboul JL. Predicting fluid responsiveness in ICU patients: a critical analysis of the evidence. Chest 2002; 121:2000.

4. Michard F, Boussat S, Chemla D, et al. Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure. Am J Respir Crit Care Med 2000; 162:134.