Perfusion index as a tool to evaluate the efficacy of stellate ganglion block for complex regional pain syndrome
Vasomotor disturbance symptoms such as abnormal thermal sensation are common in patients with complex regional pain syndrome (CRPS) . Sympathetic blocks can be applied to treat such vasomotor symptoms, and stellate ganglion block (SGB) is commonly used to manage CRPS involving the upper extremities . To date, observations of the temperature increase on the treated side and the Horner’s sign have been used as indicators of successful SGB . However, in clinical practice, patients with chronic CRPS often have ambiguous changes in parameters such as temperature after a sympathetic block.
Perfusion index (PI) is a parameter calculated from photoplethysmography and reflects the perfusion state of the monitoring site. PI is expressed as the ratio (%) of the amplitude of the non-pulsatile signal to the amplitude of the pulsatile signal and its value ranges from 0.02–20% . In previous studies, PI was reported more sensitive than temperature as a parameter to measure...
KeywordsSympathetic block Stellate ganglion block Complex regional pain syndrome Temperature Perfusion index
Complex regional pain syndrome
Stellate ganglion block
Side differences in perfusion index increase
Side differences in temperature increase
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