Anesthesia & Clinical Research
Open Access

Abstract

Training Improves the Ability of Anesthesia Providers to Visually Estimate Systolic Pressure Variation “Eyeball Technique”

Franziska E Blum, Douglas A Colquhoun and Robert H Thiele

Inappropriate fluid management may lead to patient morbidity. Systolic Pressure Variation (SPV) in % is a simple measure of arterial respiratory variation and reflects fluid responsiveness. Previous analysis of simulated blood pressure data suggest that physicians usually make correct treatment decisions based on their visual estimate of SPV%, but have poor accuracy. The purpose of this study was to determine whether training could improve the ability of physicians to visually estimate SPV%. Methods 50 anesthesia providers were asked to give their visual estimate of SPV% on 10 arterial waveform tracings displayed for 45 seconds each. At all ten waveforms were played, the true values of SPV% were revealed. After one to two weeks the same group of physicians was reassessed on their visual estimate of SPV% by displaying 10 new arterial waveform tracings for 45 seconds each. The mean bias decreased from 1.2% to 0.032% and the distribution of error was significantly different between the pre-training and the post-training group (p=0.018). The percentage of incorrect treatment decisions decreased from 4.4% to 0.85%. Conclusion Physicians experience a learning effect from visually estimating SPV%. As knowledge about how to utilize arterial respiratory variation in clinical practice increases, dedicated training may be useful. Additional studies to determine the ability of clinicians to measure changes in respiratory variation are warranted.