Changes in pulse pressure variation and plethysmographic variability index caused by hypotension-inducing hemorrhage followed by volume replacement in isoflurane-anesthetized dogs

Abstract

Results suggested that both PPV and PVI may be useful for identification of dogs that respond to VR with increases in SI and CI (ie, dogs in the preload-dependent limb of the Frank-Starling curve).

Evaluation of pulse pressure variation and pleth variability index to predict fluid responsiveness in mechanically ventilated isoflurane‐anesthetized dogs

“…Both PPV and PVI are derived from respiratory changes in arterial blood pressure waveform and the plethysmography waveform of a noninvasive pulse oximeter caused by positive pressure ventilation (Figure ). In mechanically ventilated anesthetized dogs, PPV and PVI increased consistently with decreased blood volume and decreased with volume expansion . In hypovolemic or hemorrhagic patients, the intrathoracic veins are compressed by the raised intrathoracic pressure, causing large oscillations in SV and arterial pressure, thus increase in PPV and PVI.…”

“…Pulse pressure variation (PPV) and pleth variability index (PVI) are dynamic parameters that are measurable in veterinary practice . Both PPV and PVI are derived from respiratory changes in arterial blood pressure waveform and the plethysmography waveform of a noninvasive pulse oximeter caused by positive pressure ventilation (Figure ).…”

A pilot study evaluating adaptive closed‐loop fluid resuscitation during states of absolute and relative hypovolemia in dogs

“…The diagnostic accuracy of most dynamic indices currently being used to assess fluid responsiveness has been statistically evaluated by “grey zone analysis.” In the grey zone analysis approach, fluid responders and nonresponders can be identified with high certainty while no specific conclusion on fluid responsiveness of cases in the grey zone can be made. Thresholds for fluid administration have been established for people and are being developed for dogs . We employed the Vigileo Flo‐Trac sensor to estimate SVV.…”

“…Subsequently, stroke volume and arterial pressure decrease due to a decrease in right ventricular filling . Mechanical ventilation, therefore, can be employed experimentally and clinically to increase and decrease a variety of dynamic hemodynamic indices including systolic pressure variation (SPV), pulse pressure variation (PPV), stroke volume variation (SVV), and plethysmography variability index (PVI) in order to assess vascular volume status and fluid responsiveness …”

Anesthesia-Associated Relative Hypovolemia: Mechanisms, Monitoring, and Treatment Considerations

“…It is important to note that clinical use of these indices must be investigated in detail, in each species, before translation into clinical practice is feasible. For example, does the dogs’ greater chest wall compliance relative to lung compliance impact predictive and cutoff values for each dynamic index ( 160 – 162 ). Lower HR and respiratory rates in horses may also pose limitations ( 140 ).…”