Evaluation of Perfusion Index as a Predictor of Vasopressor Requirement in Patients with Severe Sepsis

Abstract

We evaluated the ability of perfusion index (PI) to predict vasopressor requirement during early resuscitation in patients with severe sepsis. All consecutive patients with clinically suspected severe sepsis as defined by the criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference were included. Perfusion variables included PI, arterial lactate level, central venous oxygen saturation, and the difference between central venous carbon dioxide and arterial carbon dioxide pressures, and were recorded before resuscitation and 6 h thereafter. We enrolled 36 patients with severe sepsis. Twenty-one patients required vasopressors, whereas 15 did not. The cut-off of the PI value for predicting vasopressor requirement was ≤0.3. This cut-off value had a sensitivity of 100% and a specificity of 93%; the area under the curve was 0.96 (95% confidence interval 0.8-0.99, P < 0.0001). The cut-off of the arterial lactate level for predicting vasopressor requirement was ≥1.8 mg dL. This cut-off value had a sensitivity of 82% and a specificity of 80%; the area under the curve was 0.84 (95% confidence interval 0.68-0.94, P < 0.0001). Other perfusion variables failed to predict vasopressor requirement in patients with severe sepsis. We concluded that PI and arterial lactate level are good predictors of vasopressor requirement during early resuscitation in patients with severe sepsis. Further studies are warranted to investigate whether monitoring PI during resuscitation improves the outcome of patients with septic shock.

Perfusion indices revisited

“…In critically ill patients, PPI less than 1.4 is a marker of hypoperfusion [45]; also, PPI less than 0.6 is an independent factor for 30-day mortality [46]. In septic shock patients, PPI less than 0.3 predicted vasopressor therapy [47] and below 0.2 predicted mortality [48]. …”

Use of perfusion index to detect hemodynamic changes in endotoxemic pigs

“…PI may be a valuable adjunct to systemic monitoring for the detection of acute hemodynamic responses to LPS, even in the absence of changes in HR and MAP. Although several studies have identified PI as an important factor in critically ill people, 11,42 this result adds to our knowledge of PI, and may have useful implications in veterinary medicine. Given that pulse oximeters are used extensively in many clinical environments, PI values may be easily obtained and used as a complementary hemodynamic assessment.…”

“…Changes in mean arterial pressure (MAP) and heart rate (HR) may not detect this decrease in peripheral perfusion 4,5 . Studies have shown that persistent impairment in peripheral perfusion is related to a poor outcome in critically ill patients, 10 and peripheral perfusion can also predict vasopressor requirement during resuscitation in people with sepsis 11 . Although measures of peripheral perfusion have been shown to be a stronger predictor of survival than MAP and HR in patients with septic shock, guidelines for volume resuscitation are still based on MAP and HR, 6‐8 primarily because methods for evaluating peripheral perfusion are largely indirect and subjective.…”

The use of peripheral perfusion index as a predictor for patient’s response to deliberate hypotension during functional endoscopic sinus surgery. A prospective observational study

“…There is an evidence that lower PPI in critically-ill patients may reflect a high baseline sympathetic tone. Rasmy and colleagues [16] evaluated the ability of PPI to predict vasopressor requirements during early resuscitation in 36 patients with severe sepsis. They found that a low baseline PPI <0.3 had a sensitivity of 100% and a specificity of 93% for predicting vasopressor requirement.…”