The physiological responses of healthy youth to doing chest compression as a feedback of the quality and intervention effects of CPR after their rapid ascent to high altitude / 中华急诊医学杂志

ABSTRACT

Objective To investigate the physiological responses of healthy youth to doing chest compression as a feedback of quality of CPR after their rapid ascent to high altitude and to evaluate the feedback in the intervention effects of CPR.Methods Prospective,single sample,before-after comparison method was used in this study.Fifteen young adults from plains natives were enrolled as trial subjects in this study.All of them received basic life support training course in advance.In Chongqing (259 m above sea level),subjects performed empiric chest compressions on the model body for 4 minutes followed by feedback compressions for 4 minutes after at least 30 minutes rest.Compression depth,rate and other compression quality parameters were measured and recorded at each turn of compressions with an AED PLUS device.Subjects performed empiric compressions based on their knowledge and experiences,and practiced feedback compressions according to the audiovisual guidance of AED PLUS device.Blood pressure,heart rate and SpO2 were taken before and after each turn of compressions.One week after arrival to Lhasa (3658 m above sea level) by flight,all subjects were asked to do the same procedure as did in Chongqing to see their physiological response to.Paired t tests or Wilcoxon matched pair rank test were used for comparisons of measurements before and after trials.Results Systolic pressures,diastolic pressures,heart rates at baseline in Lhasa were significant different from those in Chongqing,including systolic pressure (125.9 ±9.5) mmHg vs.(112.7 ±13.4) mmHg,diastolic pressure (75.3 ±7.7) mmHg vs.(64.2 ±7.3) mmHg,heart rate (86.3 ± 13.0) beat/min vs.(72.7 ± 11.6) beat/min,SpO2 (90.4 ± 1.7)％ vs.(97.8 ±0.9)％,all P ＜ 0.01.In Lhasa,empiric compressions only caused an increase in heart rate (91.1 ± 14.9) beat/min vs.(86.3 ± 13.0) beat/min,P ＜ 0.01.However,feedback compressions resulted in a significant decrease in SpO2 [(88.3 ± 3.4) ％ vs.(90.6 ± 1.9) ％,P ＜ 0.01] as well as change of systolic pressure [(130.9 ± 11.7) mmHg vs.(120.1 ± 11.9) mmHg,P ＜0.05] and heart rate [(87.9 ± 17.5) beat/min vs.(80.9 ± 11.7) beat/min,P ＜0.05].In Lhasa,the compression quality during feedback compressions was closer to guideline recommendation than that during empiric compressions.The median (interquartile range) of composite qualification rate was 43.6％ (55.9％) vs.0.6％ (5.3％) during feedback compressions and empiric compressions respectively,P ＜ 0.01.Conclusions Compression quality decreased significantly among youth after rapid ascent to high altitude.Feedback techniques for CPR could effectively guide the rescuer to improve their CPR quality,but it may be at the expense of more physical consumption.