Peripheral perfusion response to semiorthostatic stress: a simple method for assessing autonomic dysfunction in sepsis?

Objective: To evaluate whether the perfusion index response to semiorthostatic stress can be used to monitor the sympathetic-vascular response in sepsis patients.

Methods: Three groups were studied: Group A (30 healthy patients), Group B (30 critically ill patients without sepsis), and Group C (92 septic patients). The patients underwent a semiorthostatic stress test (head elevation from 0 to 60 degrees), and hemodynamics, perfusion index values and cardiac ultrasound data were evaluated. SOFA scores were also evaluated in septic patients, comparing those with increased and decreased perfusion indices after the test.

Results: After the test, Group A presented significant reductions in stroke volume (p < 0.01) and the cardiac index (p < 0.05), with increases in heart rate (p < 0.05) and mean arterial pressure (p < 0.001). These responses were not observed in Groups B and C. In the individual analysis of Group A, there was a decrease in the perfusion index (p < 0,001), whereas in Groups B and C, the response was heterogeneous. Additionally, septic patients who had a reduced perfusion index after the test had a significant decrease in the SOFA score at 72 hours compared with the group with an increased perfusion index (p < 0.05). However, the delta-SOFA score did not differ between the groups.

Conclusion: The perfusion index response to semiorthostatic stress in sepsis patients is a simple and inexpensive method that can be used to detect the sympathetic-microvascular response at the bedside and appears to have prognostic value.