09-여현철

대한응급의학회지제 26 권제 6 호 Volume 26, Number 6, December, 2015 원 저 Education 2 인구조자심폐소생술에서인공호흡횟수를세는것이가슴압박중단시간과가슴압박분율에미치는영향 : 마네킹선행연구 성균관대학교의과대학강북삼성병원응급의학과, 동국대학교의과대학일산병원응급의학과 1 여현철 이현정 나지웅 신동혁 한상국 최필조 이정훈 1 서준석 1 The Effect of Counting Numbers out for Giving Breaths on the Interrupting Time and Fraction of Chest Compressions in 2- rescuer Cardiopulmonary Resuscitation: A Manikin Pilot Study Hyun Chul Yeo, M.D., Hyun Jung Lee, M.D., Ji Ung Na, M.D., Dong Hyuk Shin, M.D., Sang Kuk Han, M.D., Pil Cho Choi, M.D., Jeong Hun Lee, M.D. 1, Jun Seok Seo, M.D. 1 Purpose: The aim of this study was to estimate the effect of counting numbers out for giving breaths on the interruption time (IT) of chest compressions (CCs) and chest compression fraction (CCF) in the 2-rescuer cardiopulmonary resuscitation (CPR). Methods: Thirty medical students were enrolled in this randomized control simulation study, and were randomly divided into the control group and the study group. Both groups performed 2-rescuer CPR for 5-cycles with giving breaths using a bag-mask. Only participants in the study group were instructed to count numbers out for each breath verbally ( one, two ) at the end point of each inspiration period and immediately perform CCs at the point of counting two. Results: However, no differences in terms of depth, rate, incorrect location, and duty cycle of CCs, as well as ventilation volume of each breath, time to delivery of two breaths, and counts of breathing during 1 minute were observed between the two groups. Conclusion: The study group had significantly shorter IT and higher CCF compared with the control group. And no 책임저자 : 최필조서울특별시종로구새문안로 29 성균관대학교의과대학강북삼성병원응급의학과 Tel: 02) 2001-2488, Fax: 02) 2001-2891 E-mail: pcmd.choi@samsung.com 접수일 : 2015년 8월 24일, 1차교정일 : 2015년 8월 25일게재승인일 : 2015년 10월 8일 significant differences in the other measured parameters of CPR quality were observed between the two groups. Key Words: Heart massage, Respiration, Artificial respiration, Manikins Department of Emergency Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Department of Emergency Medicine, College of Medicine, Dongguk University, Goyang 1, Korea Article Summary What is already known in the previous study Interruption of chest compression should be minimized to provide high quality CPR. During 30:2 CPR, time spent for ventilations is a major determinant of chest compression fraction. What is new in the current study Counting numbers out during ventilations improved chest compression fraction by reducing time spent for ventilations. 서 2010년국제심폐소생술지침에서는고품질의심폐소생술을한층강조하고있으며, 이를위해서는충분한가슴압박의깊이와속도, 압박간가슴의완전한이완, 과호흡의회피와더불어가슴압박중단시간을최소화하는것이매우중요하다 1). 현재심폐소생술지침에는교육을받은구조자의경우가슴압박과더불어인공호흡을제공하도록되어있다 2). 심폐소생술과정에서 2회의인공호흡에의한가슴압박중단은맥박과리듬확인, 제세동의적용및명확한기도확보등으로인한압박중단시간에비해짧은시간이지만, 기관내삽관을수행하기전까지빈번히가슴압박중단을유발하는원인이된다 3-6). 저자들은 2인구조자심폐소생술에서주기적으로반복되는인공호흡으로인한가슴압박중단시간을단축할수있다면, 가슴압박분율 (chest 론 557

558 / 대한응급의학회지 : 제 26 권제 6 호 2015 compression fraction) 을향상할수있다고판단하였다. 현재 2인구조자심폐소생술지침에서는가슴압박을시행하는구조자는압박횟수를소리내어세도록권장함으로써구조자의역할교대를원활하게할뿐아니라, 압박횟수의혼동을예방하고인공호흡시행하는구조자가인공호흡제공시점을예상할수있도록하고있다 2). 그러나가슴압박을시행하는구조자는인공호흡의종료시점을스스로판단하여가슴압박을다시시작해야하는실정이다. 이에저자들은 2인구조자심폐소생술과정에서인공호흡으로인한가슴압박중단시간을단축시키기위해백-마스크인공호흡시행자가 2번째인공호흡제공종료시점에서횟수를큰소리로세도록하였고가슴압박시행자는횟수소리에반응하여즉시가슴압박을시작하도록하는방법을고안하였다 (Fig. 1). 이러한방법으로 2인구조자심폐소생술을시행할경우각주기마다가슴압박중단시간을단축시키고결과적으로가슴압박분율을향상시킬수있을것이라가정하였고, 이를확인하기위하여본연구를시행하게되었다. 대상과방법 1. 연구대상및디자인연구대상은 2015년 2월부터 4월까지본대학의교과과정에따라응급의학과임상실습중인본과 4학년학생들로, 2주간의실습기간중 1주차에본대학의응급의학과교육과정에 3시간이배정되어있는기본심폐소생술강의 와실기교육을이수한자를대상하였다. 본연구는마네킹을이용한시뮬레이션연구로서집단무작위할당방식을이용하였다. 연구는실습 2주차에본원심폐소생술교육장에서심폐소생술실기평가과정으로진행되었다. 실습조는모두 4개의조로각실습조는 7명또는 8명으로구성되었다. 조별무작위할당은실험시행직전각조의조장이 A, B, C, D가기재된카드를뽑아 A와 B는대조군, C와 D 는실험군으로배정하였으며, 이후각군의가슴압박과인공호흡의역할담당순서는번호표를뽑아순번에따라순차적으로시행하도록하였다. 2. 연구과정및방법결정된순번에의해결정된 2명의참여자를가슴압박과인공호흡의역할을배정하여, 순차적으로앞번호의참여자는가슴압박을담당하고뒤번호의참여자는인공호흡을담담하게하였다. 참여자는바닥에위치한성인마네킹 (Resusci Anne manikin, Laerdal Medical, Stavanger, Norway) 에현재의 2인구조자기본심폐소생술지침에따라 30:2의가슴압박과인공호흡의비율로다섯주기를시행토록하였다. 인공호흡은백-밸브-마스크장비 (Laerdal Silicone Resuscitator, Laerdal Medical, Stavanger, Norway) 를이용하여시행하였다. 실험데이터는마네킹에연결된 Laerdal PC SkillReporting System (Laerdal Medical, Stavanger, Norway) 을통해수집하였으며, 연결된컴퓨터화면은참여자가볼수없도록하였다. 실험전모든참여자를대상으로 3분정도의구두설명을통해 2인구 Fig. 1. Diagram explaining the hypothesis of this study. Rescuers were instructed to count numbers out loud at the moment of releasing the bag. Black dot ( ) on thin black waves illustrates time point of resuming chest compression without counting numbers out. Black diamond ( ) on thick black waves illustrates time point of resuming chest compression with counting numbers out. Asterisk (*) indicates possible time gap between the two methods.

여현철외 : 2 인구조자심폐소생술에서인공호흡횟수를세는것이가슴압박중단시간과가슴압박분율에미치는영향 : 마네킹선행연구 / 559 조자심폐소생술에따라인공호흡시행자는각인공호흡은마네킹의가슴의상승을관찰하면서 1초에걸쳐제공하고, 가슴압박시행자는 2회의인공호흡제공이완료된후즉시가슴압박을재개하도록교육하였다. 다만실험군의구두설명에는인공호흡시행자가호흡제공시백을쥐어짰다가손을떼는시점에제공횟수를 하나, 둘 크게소리내어세도록하고, 가슴압박시행자는 둘 을세는소리가들림과동시에가슴압박을재개하도록하는내용을추가하였다. 3. 결과지표측정 1) 1차결과지표 Laerdal PC SkillReporting System을이용하여수집된자료중 5주기의가슴압박과인공호흡동안의총가슴압박의중단시간과가슴압박분율을 1차결과지표로선정하였다. 2) 2차결과지표 Laerdal PC Skill Reporting System을이용하여 5주기의가슴압박과호흡제공동안의수집된자료중가슴압박의관한지표로는가슴압박의깊이, 속도, 위치, 불완전이완의횟수, 압박 / 이완비율을 2차결과지표로결정하였으며, 인공호흡에관한지표로는 1회평균호흡량과인공호흡제공시간, 분당호흡횟수로결정하였다. 4. 통계방법통계분석은 STATA 13.0 for Windows (StataCorp, College Station, USA) 프로그램을사용하였다. 정규성검사에서가슴압박속도, 압박 / 이완비율, 압박중단시간, 가슴압박분율등은정규성을만족하였으나나머지변수는정 규분포를따르지않았고연구대상자의수가각군당 15명으로적어일괄적으로연속형변수는 Mann-Whitney U test를사용하였고, 범주형변수는 Fisher s exact test로비교하였다. 연속형변수는중앙값과사분위범위로제시하였고, 범주형변수는빈도수 (%) 로기술하였다. 통계적유의성은 p-value 0.05 미만으로하였다. 결과참여자는실험군과대조군에각 15명씩분배되었고총 30명의자료를수집하여분석하였다. 참여자의성별은실험군에서남자가 9명 (60%), 대조군에서남자가 11명 (73.3%) 으로통계적차이는없었다 (p=0.700). 참여자의나이는실험군이 24세 (Interquartile range; IQR, 23-25), 대조군이 23세 (23-24) 로차이가없었다 (p=0.496). 1. 가슴압박중단시간각주기와 5-주기동안의평균가슴압박중단시간은대조군이각각 5초 (4-6) 와 24초 (16-26), 실험군은 3초 (2-3) 와 14초 (11-18) 로실험군에서통계적으로의미있게단축되었다 (p<0.01). 또한, 5주기동안의가슴압박분율역시대조군이 76.47% (74.51-82.80) 인데반해실험군은 84.95% (80.20-87.21) 로의미있게향상되었다 (p<0.01) (Table 1). 2. 가슴압박관련지표가슴압박깊이의중앙값은대조군이 59 mm (59-60), Table 1. Interruption of chest compressions. Control group Study group p value Total interruption time during 5 cycles, sec 24 (16-26) 14 (11-18) 0.002 Average interruption time per cycle, sec 5 (4-6) 3 (2-3) 0.000 Chest compression fraction, % 76.47 (74.51-82.80) 84.95 (80.20-87.21) 0.001 Data were presented as median (IQR). Table 2. Quality of chest compressions. Control group Study group p value Depth, mm 59 (59-60) 60 (59-60) 0.208 Rate, counts/min 121 (118-125) 122 (114-124) 0.317 Number of chest compressions per minute 94 (90-99) 103 (99-107) 0.000 Incorrect hand location, counts 0 (0-18) 2 (0-83) 0.380 Incomplete chest recoil, counts 0 (0-0) 0 (0-0) 0.858 Duty cycle, % 43 (38-44) 41 (37-46) 0.724 Data were presented as median (IQR).

560 / 대한응급의학회지 : 제 26 권제 6 호 2015 실험군이 60 mm (59-60) 로모두가이드라인의기준인 50 mm보다깊었으며두군간의통계적차이는없었다 (p=0.208). 가슴압박속도역시대조군이 121회 / 분 ( 118-125), 실험군이 122회 / 분 (114-124) 으로차이가없었다. 잘못된가슴압박위치, 불완전한이완, duty cycle 등에서도두그룹간차이는없었다 (Table 2). 3. 인공호흡관련지표 1회평균호흡량은대조군이 503 ml (465-608), 실험군이 480 ml (378-623) 로통계적으로차이가없었다 (p=0.493). 또한, 1회호흡제공평균시간과분당평균인공호흡횟수에서도두그룹간차이가없었다 (Table 3). 고찰본연구에서 5주기의가슴압박과인공호흡동안실험군의가슴압박중단시간의중앙값이대조군에비하여약 10 초단축되었으며, 결과적으로가슴압박분율의중앙값이 8.48% 향상되었다. 심폐소생술중가슴압박의중단은맥박과리듬확인, 제세동의적용및명확한기도확보등다양한단계에서발생할수있다 3,4,7). 가슴압박중단은자발순환회복에중요한관상동맥관류압의급격한하강을유발하며, 만약가슴압박의중단시간이길어질경우가슴압박을다시시행하더라도관상동맥관류압은가슴압박이전수준으로의회복이지연되거나어려울수있다 8-11). 또한가슴압박의중단은명확한기도확보전인공호흡을시행하는과정에서발생하게된다. 2005년심폐소생술지침에서는가슴압박과인공호흡의비율을 15:2에서 30:2로변경함으로써인공호흡제공으로인한가슴압박의중단을줄이고자하였다 12). 현재의심폐소생술지침에서는 2회의인공호흡제공하는데있어 5초를초과하지않도록제시하고있다 2). 이론상 1회의인공호흡주기가 1초에걸친인공호흡제공과약 1초동안의수동적호기로구성됨을고려할때 2회의인공호흡을완료하는데는 4초가소요된다. 그러나수동적호기중에가슴압박시행이시행되는것은환기및위팽만과관련이없으므로이러한점을고려하면 2번째인공호흡제공이완료된시점, 즉약 3초가경과한시점을가슴압박시작이가능한시점으로설정할수있을것이다. 본 연구의대조군에서 2회의인공호흡제공으로인한가슴압박중단시간은약 5초정도로측정되었다. 이전의몇몇연구들에서도백-마스크를이용한 2회인공호흡제공으로약 5~6초정도의가슴압박의중단이발생하는것을보고하고있다 5,13-15). 이러한결과들이현재의심폐소생술지침을준수하지못했다고판단할수는없으나, 이론적기간보다상대적으로연장된가슴압박중단시간은가슴압박을시행하는구조자가시각을통해인공호흡의종료시점을스스로판단하여가슴압박을다시시작해야하는것에서원인을찾을수있을것이다. 가슴압박분율은심폐소생술시행시간중가슴압박이이루어진시간의비율로정의되며, 이전연구들에따르면가슴압박분율의향상은심정지환자의자발순환회복의가능성을높이는데중요한요소로보고하고있다. Cristenson 등 16) 은병원전심실세동심정지에서가슴압박분율이환자의생존을결정하는중요한요소라고보고하였다. 이들의연구에따르면가슴압박분율이향상될수록예상조정선형효과 (estimated adjusted linear effect) 의양상으로자발순환회복의가능성을높인다고보고하였다. 이후 Christenson 등 17) 은심실세동이아닌리듬의심정지환자를대상으로한연구에서도역시가슴압박분율이높을경우자발순환회복의가능성이향상되는것으로보고하였다. 최근발표된미국심장협회의방침에따르면가슴압박분율을 80% 이상으로유지하도록제시하고있으며, 이를위해대표적으로제세동시행전후와명확한기도확보단계에서의압박중단을최소화하도록권장하고있다 18). 하지만이전연구들에따르면대부분심폐소생술과정에서권장되는가슴압박분율의목표값에도달하지는못하고있다 6,16,17,19-22). 물론가슴압박분율의향상을위해서는현재심폐소생술지침에서가슴압박중단의최소화를위해제시한권장사항들을준수하고자하는노력이선행되어야할것이다. 그러나본연구모델에서제세동이나기관내삽관등에의한가슴압박중단이없었음에도불구하고, 전통적 2인구조자심폐소생술에서상대적으로연장된인공호흡제공시간으로인해가슴압박분율의결과가약 76% 로측정되었다는것은인공호흡제공으로인한가슴압박중단시간의단축이이루어지지않는다면, 이러한목표를사실상달성하기어려울수있음을나타낸다고하겠다. 저자들은본연구를통해전통적 2인구조자심폐소생술에서인공호흡으로인한가슴압박의중단시간을단축할필요가있으며, 이 Table 3. Parameters associated with rescuer-breathing. Control group Study group p value Mean ventilation volume, ml 503 (465-608) 480 (378-623) 0.493 Mean delivery time, sec 0.9 (0.7-1.4) 0.7 (0.6-0.9) 0.173 Number of ventilation per minute 6 (4-7) 7 (4-7) 0.496 Data were presented as median (IQR).

여현철외 : 2 인구조자심폐소생술에서인공호흡횟수를세는것이가슴압박중단시간과가슴압박분율에미치는영향 : 마네킹선행연구 / 561 를위해인공호흡을담당하는구조자가인공호흡의종료시점을명확히알려줌으로써, 가슴압박이즉시다시시작되도록하는것을적용가능한방법으로제안하고자한다. 본연구에는다음과같은제한점이있다. 첫째, 본연구는가슴압박과인공호흡의 5주기만을시행한마네킹시뮬레이션연구로실제임상의심폐소생술상황에적용하는데는상당한한계가있다. 둘째, 적은수의연구대상으로인해연구결과를일반화하기어려우며, 참여자가학생들이므로실제심폐소생술의경험이있는그룹에서는다른차이를보일수있다. 셋째, 두군의연구참여자가느끼는수행의난이도나피로도등을비교하여객관적으로제시하지못했다는점등으로사료된다. 또한, 본연구가학생들의실기평가과정에서취합된자료를토대로시행되었다는점에서술기에대한집중도가일반적상황에비해상대적으로높을수있음을고려해야할것으로생각된다. 결 백-마스크를이용한전통적 2인구조자심폐소생술에서인공호흡시행자가호흡제공이종료되는시점에제공횟수를세도록하여가슴압박의재개시점을명확히알리는것이인공호흡으로인한가슴압박의중단시간을단축시킬수있었으며, 결과적으로가슴압박분율을향상시킬수있었다. 론 참고문헌 01. Nolan JP, Soar J, Zideman DA, Biarent D, Bossaert LL, Deakin C, et al. European Resuscitation Council Guidelines for Resuscitation 2010 Section 1. Executive summary. Resuscitation. 2010;81:1219-76. 02. Koster RW, Baubin MA, Bossaert LL, Caballero A, Cassan P, Castren M, et al. European Resuscitation Council Guidelines for Resuscitation 2010 Section 2. Adult basic life support and use of automated external defibrillators. Resuscitation. 2010;81:1277-92. 03. Cunningham LM, Mattu A, O'Connor RE, Brady WJ. Cardiopulmonary resuscitation for cardiac arrest: the importance of uninterrupted chest compressions in cardiac arrest resuscitation. Am J Emerg Med. 2012;30:1630-8. 04. Souchtchenko SS, Benner JP, Allen JL, Brady WJ. A review of chest compression interruptions during out-ofhospital cardiac arrest and strategies for the future. J Emerg Med. 2013;45:458-66. 05. Ruiz J, Ayala U, Ruiz de Gauna S, Irusta U, Gonzalez- Otero D, Alonso E, et al. Feasibility of automated rhythm assessment in chest compression pauses during cardiopulmonary resuscitation. Resuscitation. 2013;84:1223-8. 06. Kramer-Johansen J, Wik L, Steen PA. Advanced cardiac life support before and after tracheal intubation--direct measurements of quality. Resuscitation. 2006;68:61-9. 07. Travers AH, Rea TD, Bobrow BJ, Edelson DP, Berg RA, Sayre MR, et al. Part 4: CPR overview: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2010;122:S676-84. 08. Paradis NA, Martin GB, Rivers EP, Goetting MG, Appleton TJ, Feingold M, et al. Coronary perfusion pressure and the return of spontaneous circulation in human cardiopulmonary resuscitation. JAMA. 1990;263:1106-13. 09. Berg RA, Sanders AB, Kern KB, Hilwig RW, Heidenreich JW, Porter ME, et al. Adverse hemodynamic effects of interrupting chest compressions for rescue breathing during cardiopulmonary resuscitation for ventricular fibrillation cardiac arrest. Circulation. 2001;104:2465-70. 10. Reynolds JC, Salcido DD, Menegazzi JJ. Coronary perfusion pressure and return of spontaneous circulation after prolonged cardiac arrest. Prehosp Emerg Care. 2010;14: 78-84. 11. Sutton RM, Friess SH, Maltese MR, Naim MY, Bratinov G, Weiland TR, et al. Hemodynamic-directed cardiopulmonary resuscitation during in-hospital cardiac arrest. Resuscitation. 2014;85:983-6. 12. Handley AJ, Koster R, Monsieurs K, Perkins GD, Davies S, Bossaert L, et al. European Resuscitation Council guidelines for resuscitation 2005. Section 2. Adult basic life support and use of automated external defibrillators. Resuscitation. 2005;67 Suppl 1:S7-23. 13. Jensen JL, Walker M, LeRoux Y, Carter A. Chest compression fraction in simulated cardiac arrest management by primary care paramedics: King laryngeal tube airway versus basic airway management. Prehosp Emerg Care. 2013;17:285-90. 14. Kim KS, Na JH, Lee KH, Lee KR, Hong DY, Baek KJ, et al. Study of a Modified Two-person Cardiopulmonary Resuscitation Method to Provide Effective Ventilation: Analysis Based on a Rescuer's Training Proficiency. J Korean Soc Emerg Med. 2014;25:427-34. 15. Shim H, Park S, Lee Y, Yoo Y, Hong D, Baek K, et al. Effectiveness of a modified 2-rescuer cardiopulmonary resuscitation technique using a bag-mask for less experienced health care providers: a randomised controlled simulation study. Hong Kong J Emer Med. 2015;22:23. 16. Christenson J, Andrusiek D, Everson-Stewart S, Kudenchuk P, Hostler D, Powell J, et al. Chest compression fraction determines survival in patients with out-ofhospital ventricular fibrillation. Circulation. 2009;120: 1241-7. 17. Vaillancourt C, Everson-Stewart S, Christenson J,

562 / 대한응급의학회지 : 제 26 권제 6 호 2015 Andrusiek D, Powell J, Nichol G, et al. The impact of increased chest compression fraction on return of spontaneous circulation for out-of-hospital cardiac arrest patients not in ventricular fibrillation. Resuscitation. 2011;82: 1501-7. 18. Meaney PA, Bobrow BJ, Mancini ME, Christenson J, de Caen AR, Bhanji F, et al. Cardiopulmonary resuscitation quality: [corrected] improving cardiac resuscitation outcomes both inside and outside the hospital: a consensus statement from the American Heart Association. Circulation. 2013;128:417-35. 19. Abella BS, Alvarado JP, Myklebust H, Edelson DP, Barry A, O'Hearn N, et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. JAMA. 2005;293: 305-10. 20. Wik L, Kramer-Johansen J, Myklebust H, Sorebo H, Svensson L, Fellows B, et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. JAMA. 2005;293:299-304. 21. Gray R, Iyanaga M, Wang HE. Decreases in basic life support chest compression fraction after advanced life support arrival. Resuscitation. 2012;83:e208-9. 22. Vadeboncoeur T, Stolz U, Panchal A, Silver A, Venuti M, Tobin J, et al. Chest compression depth and survival in outof-hospital cardiac arrest. Resuscitation. 2014;85:182-8.