DETERMINATION OF A THRESHOLD VALUE FOR AN OXYGEN DEFICIENCY SENSOR BY A PSYCHOPHYSIOLOGICAL TEST A. GENS, A. SCHNEIDER, I. HAIBOECK, J. MIOSGA AND C. LEDDERHOS Aerospace Medical Association 84th Annual Scientific Meeting German Air Force Institute of Aviation Medicine CHICAGO, IL May 12-16, 2013 Commander: Dr. med. F. Grell
Disclosure Information 84th Anual AsMA Scientific Meeting Andre Gens I have no financial relationships to disclose. I will not discuss off-label use and/or investigational use in my presentation. Aerospace Medical Association 84th Annual Scientific Meeting German Air Force Institute of Aviation Medicine CHICAGO, IL May 12-16, 2013 Commander: Dr. med. F. Grell
The altitude problem within aviation First experiment dealing with the physiology of high altitude First free flight of mankind Aus: RUFF, STRUGHOLD, 1. Aufl.1939 Hydrogen balloon ride (Zenith) done by Crocé - Spinelli, Sivel and Tissandier up to an altitude of up to 8790 m. Only Tissandier survived. Thus, the altitude problem with a special view to aviation issues turned into a real serious one! Slide 3 out of 17
The altitude problem within aviation Even today, oxygen deficiency still plays a very important role in flight operations Early detection of a sudden and unexpected oxygen deficiency in flight Slide 4 out of 17
Is/are transmission and/or reflectance pulse oximetry precise enough to be used within the framework of an early-warning system for oxygen deficiency? At which threshold value of oxygen saturation (pso2) should a warning system operating in real flight operations report an oxygen deficiency? Slide 5 out of 17
Subjects N = 51 6 women, 45 men Age: 30 + 9 years Valid WFV (aeromedical certification) Slide 6 out of 17
3100 WristOx with Model 8000 R Reflectance Pulse Oximeter Sensor [NONIN MEDICAL INC.] Slide 7 out of 17
Pulsoxymeter 504 [CRITICARE SYSTEMS INC.] Slide 8 out of 17
ABL800 FLEX Blood Gas Analyzer [Radiometer Medical Denmark] Slide 9 out of 17
Chronological Test Sequence Altitude [feet] Oxygen Saturation: Altitude-Time Profile Time [minutes] Slide 10 out of 17
Vienna Determination Test Subject with universal panel Slide 11 out of 17
Reflectance pulse oximeter Transmission pulse oximeter pso2 CRITICARE 504 = f (sao2 ABL 800 FLEX) [%] pso2 WristOx = f (sao2 ABL800 FLEX) [%] 100 95 pso2 WristOx [%] 90 y = 0,07x + 91,84 R2 = 0,0167; R = 0,13 95 y = - 0,03x + 101,67 R2 = 0,011; R = 0,11 y = 0,074x + 25,04 R2 = 0,6154; R = 0,78 90 y = 1,02x - 0,098 2 R = 0,751; R = 0,87 85 y = 0,96x + 4,15 R2 = 0,762; R = 0,873 y = 0,80x + 18,89 R2 = 0,7228; R = 0,85 85 80 75 70 sao2 vs. pso2 0 ft 65 Regression line Regressionsgerade 0 ft sao2 vs. pso2 15.000 ft Regression line Regressionsgerade 15.000 ft sao2 vs. pso2 18.000 ft Regression line Regressionsgerade 18.000 ft Vergleichsgerade Comparison line 60 55 50 pso2 CRITICARE 504 [%] 100 80 75 70 sao2 vs. pso2 0 ft Regressionsgerade Regression line 0 ft0 ft sao2 vs. pso2 15.000 ft 65 60 Regressionsgerade 15.000ft ft Regression line 15.000 sao2 vs. pso2 18.000 ft Regression line 18.000 ft Regressionsgerade Comparison Vergleichsgerade line 55 50 50 55 60 65 70 75 80 85 90 95 100 50 55 60 sao2 ABL800 FLEX [%] 65 70 sao2 75 80 85 ABL 800 FLEX 90 95 100 [%] Oxygen saturation which has been determined by means of pulse oximetry shows a good correlation with sao2 determined via blood Slide 12 out of 17
Comparison saturation intervals ofvon 5%jeeach Vergleich vonofsättigungsintervallen 5% 100 Sauerstoffsättigung [%] Oxygen saturation [%] 95 90 85 80 75 70 CRITICARE 504 65 WristOx ABL 800 FLEX 60 65% bis < 70% 70% bis < 75% 75% bis < 80% 80% bis < 85% 85% bis < 90% 90% bis < 95% 95% bis 100% Intervals everyje5% Intervalle 5% sao2 ABL 800 FLEX CA WA CW s.s.s. N=20 n.s.s. N=49 n.s.s. N=53 s.s.s. N=36 n.s.s. N=32 s.s.s. N=41 s.s.n. N=68 Statistische Vergleiche : Statistical comparisons: CRITICARE -ABL 800 WristOx-ABL 800 CRITICARE-WristOx Values of oxygen saturation determined via pulse oximetry are higher than oxygen saturation values measured via blood Slide 13 out of 17
Reflectance pulse oximeter Transmission pulse oximeter Local altitude Local altitude Oxygen saturation [%] Oxygen saturation [%] Oxygen saturation [%] Oxygen saturation [%] Oxygen saturation [%] Oxygen saturation [%] Oxygen saturation dependent on the altitude level shows a great inter-individual variability Slide 14 out of 17
Wrong answers Right answers Vienna Determination Test Saturation intervals of the ABL800 FLEX Saturation intervals of the ABL800 FLEX Response time Time [s] Omitted answers Saturation intervals of the ABL800 FLEX Saturation intervals of the ABL800 FLEX of responses Decreasing alertness Increased error rate High sao2 was accompanied by a better performance capability of stimuli Saturation intervals of the ABL800 FLEX Saturation intervals of the ABL800 FLEX Slide 15 out of 17
pso2 shows a good determined via blood) correlation with sao2 (which is The oxygen saturation dependent on the altitude level shows a great inter-individual variability sao2 was accompanied by decreasing alertness and an increased error rate, high sao2 on the other hand was accompanied by a better performance capability As pso2 > sao2 Recommendation The threshold value of a critical saturation loss for warning systems based on pulse oximetry should be sufficiently high, i.e. at about 90% pso2. Slide 16 out of 17
Slide 17 out of 17