Cephalic Versus Digital Plethysmographic Variability Index Measurement: A Comparative Pilot Study in Cardiac Surgery Patients

• Published in: Journal of cardiothoracic and vascular anesthesia 2014-12, Vol.28 (6), p.1510-1515
• Main Authors: Fischer, Marc-Olivier, MD, Pellissier, Arnaud, MD, Saplacan, Vladimir, MD, Gérard, Jean-Louis, MD, Hanouz, Jean-Luc, MD, PhD, Fellahi, Jean-Luc, MD, PhD
• Format: Article
• Language: English
• Subjects: Aged; Anesthesia & Perioperative Care; Arterial Pressure - physiology; Blood Pressure - physiology; Cardiac Surgical Procedures; Critical Care; Ear - blood supply; Fingers - blood supply; fluid challenge; fluid responsiveness; Fluid Therapy; Forehead - blood supply; Humans; Monitoring, Intraoperative - methods; Pilot Projects; plethysmographic variability index; plethysmography; Plethysmography - methods; Prospective Studies; pulse-pressure variation; Regional Blood Flow - physiology; ROC Curve
• ISSN: 1053-0770; 1532-8422
• DOI: 10.1053/j.jvca.2014.05.003

Objectives Noninvasive measurement of digital plethysmographic variability index (PVIdigital ) has been proposed to predict fluid responsiveness, with conflicting results. The authors tested the hypothesis that cephalic sites of PVI measurement (namely PVIear and PVIforehead ) could be more discriminant than PVIdigital to predict fluid responsiveness after cardiac surgery. Design A prospective observational study. Setting A cardiac surgical intensive care unit of a university hospital. Participants Fifty adult patients. Interventions Investigation before and after fluid challenge. Measurement and Main Results Patients were prospectively included within the first 6-hour postoperative period and investigated before and after fluid challenge. A positive response to fluid challenge was defined as a 15% increase in cardiac index. PVIdigital , PVIear , PVIforehead , and invasive arterial pulse-pressure variation (PPV) measurements were recorded simultaneously, and receiver operating characteristic (ROC) curves were built. Forty-one (82%) patients were responders and 9 (18%) patients were nonresponders to fluid challenge. ROCAUC were 0.74 (95% confidence interval [95% CI]: 0.60-0.86), 0.81 (95% CI: 0.68-0.91), 0.88 (95% CI: 0.75-0.95) and 0.87 (95% CI: 0.75-0.95) for PVIdigital , PVIear , PVIforehead , and PPV, respectively. Significant differences were observed between PVIforehead and PVIdigital (absolute difference in ROCAUC = 0.134 [95% CI: 0.003-0.265], p = 0.045) and between PPV and PVIdigital (absolute difference in ROCAUC = 0.129 [95% CI: 0.011-0.247], p = 0.033). The percentage of patients within the inconclusive class of response was 46%, 70%, 44%, and 26% for PVIdigital , PVIear , PVIforehead , and PPV, respectively. Conclusions PVIforehead was more discriminant than PVIdigital and could be a valuable alternative to arterial PPV in predicting fluid responsiveness.