Perfusion Index (PI) and Pleth Variability Index (PVI) in Patients With Interscalene Blocks in Orthopedic Surgery

An Evaluation of PI and PVI (Masimo) in Patients With Interscalene Blocks in Orthopedic Surgery

The purpose of this study is to:

1. To describe effects of interscalene nerve blocks on perfusion index (PI) and pleth variability index (PVI) (Radical 7, Masimo Cooperation, Irvine, CA) before and after induction of general anesthesia.
2. To compare effects of fluid-bolusing on PI and PVI of the anesthetized and non-anesthetized limb.

Inclusion Criteria:

• patients scheduled for shoulder or upper arm surgery
• ASA 1-3
• written informed consent
• approval from the local ethics committee

Exclusion Criteria:

• arrhythmia
• patients suffering from severe vascular disease, coronary artery (CCS IV) disease
• anaemia (haemoglobin < 7mg/dl)
• patients in whom a tidal volume of 8ml/kg cannot be delivered safely