Jean-Luc Hanouz1, Anne-Lise Fiant2, Jean-Louis Gérard3. 1. Pôle Réanimations Anesthésie SAMU, CHU de Caen, Avenue Côte de Nacre, 14033 Caen cedex, France; Laboratoire de Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA 4650, Université Caen Basse Normandie, France. Electronic address: hanouz-jl@chu-caen.fr. 2. Pôle Réanimations Anesthésie SAMU, CHU de Caen, Avenue Côte de Nacre, 14033 Caen cedex, France. 3. Pôle Réanimations Anesthésie SAMU, CHU de Caen, Avenue Côte de Nacre, 14033 Caen cedex, France; Laboratoire de Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA 4650, Université Caen Basse Normandie, France.
Abstract
OBJECTIVES: The goal of the present study was to examine changes of middle cerebral artery (VMCA) blood flow velocity in patients scheduled for shoulder surgery in beach chair position. DESIGN: Prospective observational study. SETTING: Operating room, shoulder surgery. PATIENTS: Fifty-three consecutive patients scheduled for shoulder surgery in beach chair position. INTERVENTIONS: Transcranial Doppler performed after induction of general anesthesia (baseline), after beach chair positioning (BC1), during surgery 20minutes (BC2), and after back to supine position before stopping anesthesia (supine). MEASUREMENTS: Mean arterial pressure (MAP), end-tidal CO2, and volatile anesthetic concentration and VMCA were recorded at baseline, BC1, BC2, and supine. Postoperative neurologic complications were searched. MAIN RESULTS: Beach chair position induced decrease in MAP (baseline: 73±10mm Hg vs lower MAP recorded: 61±10mm Hg; P<.0001) requiring vasopressors and fluid challenge in 44 patients (83%). There was a significant decrease in VMCA after beach chair positioning (BC1: 33±10cm/s vs baseline: 39±14cm/s; P=.001). The VMCA at baseline (39±2cm/s), BC2 (35±14cm/s), and supine (39±14cm/s) were not different. The minimal alveolar concentration of volatile anesthetics, end-tidal CO2, SpO2, and MAP were not different at baseline, BC1, BC2, and supine. CONCLUSION: Beach chair position resulted in transient decrease in MAP requiring fluid challenge and vasopressors and a moderate decrease in VMCA.
OBJECTIVES: The goal of the present study was to examine changes of middle cerebral artery (VMCA) blood flow velocity in patients scheduled for shoulder surgery in beach chair position. DESIGN: Prospective observational study. SETTING: Operating room, shoulder surgery. PATIENTS: Fifty-three consecutive patients scheduled for shoulder surgery in beach chair position. INTERVENTIONS: Transcranial Doppler performed after induction of general anesthesia (baseline), after beach chair positioning (BC1), during surgery 20minutes (BC2), and after back to supine position before stopping anesthesia (supine). MEASUREMENTS: Mean arterial pressure (MAP), end-tidal CO2, and volatile anesthetic concentration and VMCA were recorded at baseline, BC1, BC2, and supine. Postoperative neurologic complications were searched. MAIN RESULTS: Beach chair position induced decrease in MAP (baseline: 73±10mm Hg vs lower MAP recorded: 61±10mm Hg; P<.0001) requiring vasopressors and fluid challenge in 44 patients (83%). There was a significant decrease in VMCA after beach chair positioning (BC1: 33±10cm/s vs baseline: 39±14cm/s; P=.001). The VMCA at baseline (39±2cm/s), BC2 (35±14cm/s), and supine (39±14cm/s) were not different. The minimal alveolar concentration of volatile anesthetics, end-tidal CO2, SpO2, and MAP were not different at baseline, BC1, BC2, and supine. CONCLUSION: Beach chair position resulted in transient decrease in MAP requiring fluid challenge and vasopressors and a moderate decrease in VMCA.