دستگاه پالس اكسي متري در حضور شبيه سازي شوك )LAG TIME( بررسي تاثير بلوك انگشتي در ميزان اشباع هموگلوبين با اكسيژن ، ارتفاع و زمان تاخير پيدايش موج پلتيسموگرافي

Effect of Digital Block on SPao2, Lag Time and Height of Plethysmographic Wave of Pulse Oximeter by Simulated Shock

Introduction. Pulse oximetry is impaired by hypotention and peripheral vasoconstriction. Digital block may cause to increase tissue perfusion and improve the parameters of pulse oximetry. The purpose of this study was to investigate the effect of digital block on SPao2, lag time and height of plethysmographic wave of pulse oximeter by simulated shock in upper extremity. Methods. In an experimental study, 34 Paitents under general anesthesia and elective surgery were selected. Lag time and height of plethysmographic wave and SPao2 had been measured in two fingers shocked by cooling, elevation of hand and inflation of cuff; then, compared to opposite middle finger as control. shocked Middle finger were blocked by lidocaine 2% and these parameters were measured in the 15th and 20th minutes after digital block. Data analysis was performed by SPSS using ANOVA. Results. Mean height of plethysmographic wave in blocked finger was signihcontly taller than shocked and control fingers in the 15th minute (respectively, 16.9-6, 10.8±4.3, 10.7± 4.3, P<0.05) and the 20th minute afters digital block (21.1±5.8, 11.8±4.3, 11.2±3.9, P<0.05). There were not significalt differences between three fingers in lag time and SPao2. Discussion. This study documents effect of digital block, undergoing shock condition in improving the parameters of pulse oximetry.