Technology and Health Care 22 (2014) 351–358 DOI 10.3233/THC-140791 IOS Press
351
Comparison of chest compression quality between the modified chest compression method with the use of smartphone application and the standardized traditional chest compression method during CPR Sang-Sub Parka,b,∗
a Department b Graduate
of Emergency Medical Technology, ChungCheong University, Cheongju, Korea School of Pharmacy, Korea University, Sejong-si, Korea
Received 26 October 2013 Accepted 23 January 2014 Abstract. The purpose of this study is to grasp difference in quality of chest compression accuracy between the modified chest compression method with the use of smartphone application and the standardized traditional chest compression method. Participants were progressed 64 people except 6 absentees among 70 people who agreed to participation with completing the CPR curriculum. In the classification of group in participants, the modified chest compression method was called as smartphone group (33 people). The standardized chest compression method was called as traditional group (31 people). The common equipments in both groups were used Manikin for practice and Manikin for evaluation. In the meantime, the smartphone group for application was utilized Android and iOS Operating System (OS) of 2 smartphone products (G, i). The measurement period was conducted from September 25th to 26th, 2012. Data analysis was used SPSS WIN 12.0 program. As a result of research, the proper compression depth (mm) was shown the proper compression depth (p < 0.01) in traditional group (53.77 mm) compared to smartphone group (48.35 mm). Even the proper chest compression (%) was formed suitably (p < 0.05) in traditional group (73.96%) more than smartphone group (60.51%). As for the awareness of chest compression accuracy, the traditional group (3.83 points) had the higher awareness of chest compression accuracy (p < 0.001) than the smartphone group (2.32 points). In the questionnaire that was additionally carried out 1 question only in smartphone group, the modified chest compression method with the use of smartphone had the high negative reason in rescuer for occurrence of hand back pain (48.5%) and unstable posture (21.2%). Keywords: Cardiopulmonary resuscitation, smartphone, application, chest compression
1. Introduction KACPR [1] said that the role of bystanders is crucial in the treatment of cardiac arrest. According to the report of Choi [2] on the primary implications of cardinal arrest that occurs out of hospital during five years (2006 to 2010), 44.3% of patients were not observed when having cardinal arrest while ∗ Address for correspondence: Sang-Sub Park, Graduate School of Pharmacy, Korea University, 2511, Sejong-ro, Jochiwoneup, Sejong-si, 339-700, Korea. E-mail: [email protected].
c 2014 – IOS Press and the authors. All rights reserved 0928-7329/14/$27.50
352
S.-S. Park / Comparison of chest compression quality between two groups Table 1 Characteristics of subjects Gender
Male Female
Smartphone group (n: 33) 18 (54.5) 15 (45.5)
Traditional group (n: 31) 15 (48.4) 16 (51.6)
χ2 0.243
p-value 0.622
38.2% was witnessed. During the period, only 2.1% of the observed patients of cardinal arrest received Cardio Pulmonary Resuscitation (CPR). According to the analysis attempted by Hollenberg et al. [3] on the patients who had cardinal patients out of hospital from 1992 to 2005, the percentages of patients who were witnessed of cardinal arrest were similar in 1992 and 2005. Meanwhile, the percentage of the patients not observed declined from 35% in 1992 to 29.0% in 2005. And the performance of CPR rose from 31.0% in 1992 to 50.0% in 2005. The different figures in CPR performance between Choi [2] and Hollenberg et al. [3] seem to be attributable to the difference in social and environmental factors. An emergency guideline of cardinal arrest was simplified to take more active CRP performance at the witness of patients having cardinal arrest. The simplified guideline, which was recommended by American Heart Association, AHA [4], changed the procedure of CPR from Airway-Breathing-Chest compression to Chest compression-Airway-Breathing. It also omitted look, listen, and feel from the algorithm of checking breath. It recommended hands-only CPR instead of mouth-to-mouth resuscitation in case that a CPR provider, regardless of his experience with or without CPR training, is reluctant to apply artificial respiration (mouth-to-mouth resuscitation). The guideline recommended that chest be compressed at least 5 cm deep and 100 times a minute. Recently, Smartphone is widely used to disseminate CPR. ZOLL [5] and Kovic [6] developed Pocket CPR and CPR PRO App, respectively. In addition, Koo et al. [7], NEMA [8], and MW [9] developed applications that provide information of emergency response procedure and emergent medical treatment. Pyo at el. [10] said that Smartphone application can feed back instantly, not limited to time and place, and provides users with self-educating environment. Lee [11] opinioned that Smartphone has limitless expandability using Operating System like PC as long as software needed is installed in the device. In this respect, the authors of this study attempted to examine the difference in quality between modified chest compression procedure using Smartphone and the standardized method. It aims to provide a substantial contribution to the training and education of CPR technique. 2. Methods 2.1. Characteristics of subjects Seventy participants were randomly selected from those who had completed CPR training course before and consented to the participation in the experiment. They were divided into two groups. One was Smartphone group (35) and the other was Traditional group (35). 6 participants were dropped out, so 64 participants completed this test (smartphone group of 33 and Traditional group of 31). The profiles of the participants are shown in Table 1. This experiment was conducted for two days, from the 25th to 26th of September, 2012. 2.2. Measurement This study intended to compare the difference of quality in chest compression between Smartphonebased modified method and standardized method. To do so, smartphones and manikins were used as
S.-S. Park / Comparison of chest compression quality between two groups
353
measurement tools. The participants were divided into two groups and explained of the procedures and method. They were not allowed to share their evaluations. Smartphone group, holding a smartphone between hands, performed modified chest compression. They used 5 G smartphone of S company and 5 i smartphone of A company. G smartphone is operated in Android OS while i smartphone runs in iOS. The reason why only two kinds of smartphone were used in the experiment was that they were most widely used. In addition, they were chosen because the size of smartphone is different by operating system. The participants were asked to choose a smartphone to use in order. ZOLL[5]’s Pocket CPR was used for CPR application program. The application was easily accessible and compatible to both Android and iOS. ZOLL[5]’s Pocket CPR uses the modified CPR chest compression method. The user holds a smartphone between hands watching the screen of the Smartphone while performing chest compression. The screen consists of visual and aural components such as “compression part”, “compression depth (graph)”, “Start CPR (voice)” and “Compression speed (sound)”. It has been recently upgraded and it now has a phrase “Music” and “Push Harder” instead of “Knock” sound. Traditional method group followed hand positions as suggested in the standardized guideline. They locked hands on the part of the body to be compressed and pressed them down. Figure 1 shows the hand positions of the two groups. 2.3. Measuring equipment and quality assessment items The two groups practiced chest compression on the same kind of manikin (Little AnneTM of Laerdal (Norway). Resusci Anne w/ Skillreporter System (Laerdal, Norway) was used at the final CPR performance. Assessment criteria followed 2010 Guideline [1,4] – 5 cycles of 30 times of chest compression and 2 times of artificial respirations. However, only chest compression was applied in quality assessment. Since the application program of the smartphone group only consisted of ’hands-only CPR’, artificial respiration was excluded. Measurement was carried out in a lecture room. The quality assessment items of chest compression consisted of ‘proper compression depth (mm)’, ‘average compression velocity (time/min)’, ‘accuracy of chest compression (%)’, ‘too week (time)’, poor compression site (time)’, ‘positioned too below (time)’ and ‘poor recoil (time)’. 2.4. Questionnaire The author of this study developed questionnaire (2 items). One was accuracy awareness of chest compression (5-point Likert scale), which was applied to both groups. Higher point means higher accuracy awareness of chest compression. The other was applied only to smartphone group to know how the method of the group had impact on chest compression. The questionnaires were distributed after both groups completed the final CPR performance and were asked to fill it in. The procedure is shown in Fig. 2. 2.5. Analytical method This study used SPSS 12.0 for Window. Chi-squared analysis, mean, standard deviation, Wilcoxon signed rank test, Mann-Whitney U test were employed. Significance level was set at p < 0.05.
354
S.-S. Park / Comparison of chest compression quality between two groups
Smartphone Group
Traditional Group
Fig. 1. Chest compression posture of two groups. (Colours are visible in the online version of the article; http://dx.doi.org/ 10.3233/THC-140791)
Selection of subjects (n=70)
↓
↓
Smartphone Group (n=35)
↓
Traditional Group (n=35):
↓
Non participation (2 People) Smartphone Group (n=33)
Non participation (4 People)
Traditional Group (n=31)
↓
↓
Prior practice (2 times): Little AnneTM (Leardal Co.): 3 products.
Prior practice (2 times): Little AnneTM (Leardal Co.): 3 products.
↓
↓
Final: 30 vs 2 (5 cycles): Resusci Anne w/ Skillreporter ( טLeardal Co.): 2 products. Smartphone (G product. S Co., i product. A Co.)
Final: 30 vs 2 (5 cycles): Resusci Anne w/ Skillreporter ( טLeardal Co.): 2 products.
↓ Answer to questionnaire (2 items)
↓ Answer to questionnaire (1 item)
Fig. 2. Research procedure.
3. Result 3.1. A comparison of chest compression quality between two groups Table 2 shows the comparison of chest compression quality of smartphone and traditional method group. For proper compression depth, traditional group turned out to have performed more proper compression (53.77 mm) than smartphone group (48.35 mm). The difference was statistically significant (p < 0.01). In the accuracy of chest compression, traditional method group was more accurate (73.96%) than smartphone group (60.51%). The difference was statistically significant (p < 0.05). Two groups didn’t show statistically significant difference for the rest items.
S.-S. Park / Comparison of chest compression quality between two groups
355
Table 2 A comparison of chest compression quality between two groups
Chest compression
∗
Proper compression depth (mm) Average compression velocity (time/min) Chest compression (%) Too weak (time) Poor compression site (time) Positioned too below (time) Poor recoil (time)
Smartphone group Mean ± SD 48.35 ± 9.23 108.09 ± 8.86 60.51 ± 40.00 48.83 ± 60.41 15.83 ± 39.96 0.00 ± 0.00 0.61 ± 2.70
Traditional group Mean ± SD 53.77 ± 4.41 114.25 ± 7.92 73.96 ± 30.92 33.67 ± 48.92 8.09 ± 22.35 0.80 ± 4.49 0.70 ± 2.63
p-value 0.002∗∗ 0.007∗∗ 0.015∗ 0.130 0.490 0.317 0.856
p < 0.05, ∗∗ p < 0.01.
3.2. A comparison of chest compression quality according to gender Table 3 shows the comparison of chest compression quality by Gender. For the accuracy of chest compression, males of smartphone group (72.64%) were more accurate than females of smartphone group (44.73%). The difference was statistically significant (p < 0.05). Like smartphone group, males of traditional method group were more accurate (88.33%) than females of traditional group (60.50%). The difference was statistically significant (p < 0.05). As far as ‘too weak (time)’ was concerned, females of smartphone group (80.33 times) compressed chest more weakly than males of smartphone group (24.66 times). The difference was statistically significant (p < 0.05). Meanwhile, traditional group didn’t show statistically significant difference in weak compression by Gender. Males of smartphone group (21.00 times) performed chest compression on poor site than females of smartphone group (7.53 times), but the difference wasn’t statistically significant (p < 0.05). Groups by Gender didn’t show statistically significant difference in the rest items. 3.3. Accuracy awareness of chest compression Table 4 shows the result of accuracy awareness of chest compression by group. Traditional method group (3.83) was more aware that Smartphone-based chest compression was helpful than Smartphone group (2.32). The difference was statistically significant (p < 0.001). 3.4. Effectiveness of smartphone This question was asked only to Smartphone group. The participants in this group had more negative opinion than positive on the use of smartphone for chest compression. The most reasons for the negativity included hand back pain (48.5%) and unstable posture (21.25%), which were followed by slip (18.2%), inaccurate compression site (6.1%), and dispersion concentration (6.1%) (Fig. 3).
4. Discussion In the two-group comparison, traditional group performed more quality chest compression than smartphone group. For the accuracy awareness of chest compression, traditional method group showed higher awareness. Smartphone group had more negative awareness due to pain in hands and unstable posture.
356
S.-S. Park / Comparison of chest compression quality between two groups Table 3 A comparison of chest compression quality according to gender Smartphone group Male Female Mean ± SD Mean ± SD 51.22 ± 8.01 45.00 ± 9.09
Chest Proper compression compression depth (mm) Average velocity 108.00 ± 8.49 107.66 ± 9.59 (time/min) Chest compression 72.61 ± 34.31 44.73 ± 40.04 (%) Too weak (time) 24.66 ± 37.54 80.33 ± 66.45 Poor compression 21.00 ± 50.05 7.53 ± 17.54 site (time) Positioned too 0.00 ± 0.00 0.00 ± 0.00 below (time) Poor recoil (time) 1.00 ± 3.51 0.13 ± 0.51 ∗
Pvalue 0.055
Traditional group Male Female Mean ± SD Mean ± SD 55.00 ± 3.50 52.62 ± 4.96
0.841 113.33 ± 6.45
115.12 ± 9.22
Pvalue 0.158 0.476
0.048∗
88.33 ± 18.06
60.50 ± 34.75
0.019∗
0.019∗ 0.704
15.00 ± 27.69 0.53 ± 2.06
51.18 ± 58.27 15.18 ± 29.74
0.200 0.017∗
1.000
0.00 ± 0.00
1.56 ± 6.25
0.333
0.246
1.33 ± 3.73
0.12 ± 0.34
0.497
p < 0.05. Table 4 Accuracy awareness of chest compression Awareness of accuracy Gender
∗∗∗
Male Female
M ± SD p-value Mean ± SD Mean ± SD p-value
Smartphone group Traditional group 2.32 ± 1.01 3.83 ± 0.68 0.000∗∗∗ 2.50 ± 0.78 4.07 ± 0.70 2.20 ± 1.20 3.62 ± 0.61 0.224 0.078
p < 0.001.
Fig. 3. Effectiveness of smartphone.
The experiment showed that standardized method was more effective than smartphone-based modified chest compression as a whole. Aufderheide et al. [12] reported in the comparison of a standard hand position and 3 other compression methods (Two-Finger Fulcrum Technique, Five-Finger Fulcrum Technique, Hands-Off Technique) that the standard chest compression was more proper. Also, Skogvoll and Wik [13] didn’t show, in the comparison between standardized chest compression method and ACD (Active Compression – Decompression) CardioPump , which was a chest compressor of which upper part was attached with a handler and lower part was shaped like a plate, that ACD CardioPump was better than standardized chest
S.-S. Park / Comparison of chest compression quality between two groups
357
compression method. The question why the modified chest compression methods above were not efficient seem to be answered by the different hand position, as mentioned in the Guideline [1] – “CPR can’t be varied by individual or CPR provider; CPR should be standardized to revive person with cardinal arrest; the survival rate of cardinal arrest patients can improve by standardized CPR procedure”. On the other hand, ZOLL [5,6] introduced smartphone-based modified chest compression method. ZOLL [5,6] introduced Pocket CPR , and CPR PRO App. respectively, exclusively for CPR education and training. However, the hand position and posture (holding smartphone between hands) instructed in those programs are different from those in the Guideline. Non-compliance with the directions of the Guideline or use of modified chest compression method based on smartphone can cause inaccuracy in compression depth and speed due to the pain in hands and lack of positional stability. In addition, compression should be given on chest with vertically straightened arms (elbows). However, the modified chest compression method allows arms to bend or fold, which results in inaccuracy in compression. Positional instability can cause fractures of the ribs and breastbones, liver damage, epicardial and lung bleeding [14–16]. Therefore, smartphone-based chest compression requires a special caution. In the meantime, Kovic [6], Kovic and Lulic [17] introduced a chest compression method (CPR PRO Cradlea) with smartphone held in both handlers, not held in hands, while watching the screen of the device. In addition, Kovic [6] introduced ’CPR Prompts’, which is a chest compression method using smartphone screen lying beside a patient just like Visual Feedback device. ZOLL [5] also developed an iOS-exclusive device by which Smartphone is fixed on a backhand. This device runs in “Strap device on top of hand” mode, allowing a CPR provider to watch the screen of smartphone while performing CPR. Among those products mentioned above, CPR Prompts and “Strap device on top of hand” follow the standardized chest compression procedure. Namely, they use Smartphone in various ways, but they conform to standard CPR method. Pyo et al. [10] said that learning through smartphone was a way to increase interest. Accordingly, Koo at el. [7], NEMA [8] and MW [9] developed smartphone applications that help efficiently cope with emergency through learning first aid including CPR in daily life. Their applications are not modified chest compression methods but pre-training for the standardized chest compression (self-learner puts smartphone on a chest and practice chest compression). However, chest compression method with smartphone on a chest has some limitations. First, trainees may learn wrong method of standard chest compression during education and training. Second, it is doubted that smartphone-on-chest compression can be utilized in real situation as efficiently as or better than standardized chest compression method. Third, the method may cause pain in hands and (hands’) positional stability. Therefore, it is considered that smartphone-on-chest compression method is not proper and less efficient than standardized traditional method. It is desirable that smartphone should be used a pre-learning tool for standardized chest compression method. This study has some limitations. First it limited the use of smartphone to only 2 products. Second, smartphones are varied in size by OS. Third, the experiment was done on limited number of samples. Fourth, the measurement was based on short term. Fifth, it used manikin, which is far from real situation. As a result, discretion is required in generalizing the findings of the study. Based on the findings, the standardized traditional chest compression method is considered to be likely to be necessarily maintained in the skills acquirement and the skills education compared to the modified chest compression method with the use of smartphone.
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5. Conclusions The result of the study demonstrated that standardized chest compression method in accordance with the Guideline is more appropriate for skill education and training. And it is better that smartphone is used as prerequisite learning for standardized chest compression method. More diverse researches are expected on smartphone-based chest compression methods. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
[13] [14] [15] [16] [17]
KACPR. 2011 Korean guideline for CPR ECC, www.kacpr.org. 2011. Choi JA. Result of Out-of-Hospital Cardiac Arrest Surveillance, 2006-2010. Public Health Weekly Report. http://www.cdc.go.kr. 2012; 5(41): 777-782. Hollenberg J, Herlitz J, Lindqvist J, Riva G, Bohm K, Rosenqvist M, Svensson L. Improved Survival After Out-ofHospital Cardiac Arrest Is Associated With an Increase in Proportion of Emergency Crew-Witnessed Cases and Bystander Cardiopulmonary Resuscitation. J of Circulation. 2008; 118(4): 389-396. American Heart Association(AHA). 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science, Part 5: Adult Basic Life Support. http://www.americanheart.org, 2010 ZOLL. PocketCPR Real-time CPR Feedback. http://www.pocketcpr.com, 2011. Kovic I. CPR PRO App. Ivor Medical. http://www.ivormedical.com, 2010. Koo MJ, Seo JM, Chang YH, Han WC, Baek YT, Pyo SB, Lim HJ. A Study of Coping Ways in Emergency Situations Using SmartPhones. J of Korean Society Computer Information, Winter Conference. 2012; 20(1): 87-90. National Emergency Management Agency(NEMA). Coping method for emergency situations. http://www.nema.go.kr, https://play.google.com/store/apps/details?id=com.fantalog.FirstAid&feature=search_result#?t=W10. 2010. Ministry for Health(MW). Emergency medical information provided. http://www.mw.go.kr, https://play.google.com/ store/apps/details?id=kr.go.mw&feature=search_result#?t=W10. 2012. Pyo MY, Kim JY, Sohn JO, Lee ES, Kim HS, Kim KO, Park HJ, Kim MJ, An GH, Yang JR, Yu JH, Kim YA, Kim HJ, Choi MN. The Effects of an Advanced Cardiac Life Support Training via Smartphone’s Simulation Application on Nurses’ Knowledge and Learning Satisfaction. J of Korean Clinical Nursing Research, 2012; 18(2): 228-238. Lee SM., Han MS, Park JS. A Research on the Analysis of Inhibiting Factors In Using Smartphones and the Measure of Promoting the Use of Smartphones. J of Korea Safety Management & Science. 2011; 13(4): 237-245. Aufderheide TP, Pirrallo RG, Yannopoulos D, Klein JP, Briesen C von, Sparks CW, Deja KA, Conrad CJ, Kitscha DJ, Provo TA, Lurie KG. Incomplete chest wall decompression: A clinical evaluation of CPR performance by EMS personnel and assessment of alternative manual chest compression-decompression techniques. J of Resuscitation. 2005; 64(3): 353-362. Skogvoll E, Wik L. Active compression-decompression cardiopulmonary resuscitation: a population-based, prospective randomised clinical trial in out-of-hospital cardiac arrest. J of Resuscitation. 1999; 42(3): 163-172. Smekal D, Johansson J, Huzevka T, Rubertsson S. No difference in autopsy detected injuries in cardiac arrest patients treated with manual chest compressions compared with mechanical compressions with the LUCASTM device – A pilot study. J of Resuscitation. 2009; 80(10): 1104-1107. Lederer W, Mair D, Rabl W, Baubin M. Frequency of rib and sternum fractures associated with out-of-hospital cardiopulmonary resuscitation is underestimated by conventional chest X-ray. J of Resuscitation, 2004; 60(2): 157-162. Meron G, Kurkciyan I, Sterz F, Susani M., Domanovits H, Tobler K, Bohdjalian A, Laggner AN. Cardiopulmonary resuscitation-associated major liver injury. J of Resuscitation. 2007; 75(3): 445-453. Kovic I, Lulic I. Mobile phone in the chain of survival. J of Resuscitation. 2011; 82(6): 776-779.
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351
Comparison of chest compression quality between the modified chest compression method with the use of smartphone application and the standardized traditional chest compression method during CPR Sang-Sub Parka,b,∗
a Department b Graduate
of Emergency Medical Technology, ChungCheong University, Cheongju, Korea School of Pharmacy, Korea University, Sejong-si, Korea
Received 26 October 2013 Accepted 23 January 2014 Abstract. The purpose of this study is to grasp difference in quality of chest compression accuracy between the modified chest compression method with the use of smartphone application and the standardized traditional chest compression method. Participants were progressed 64 people except 6 absentees among 70 people who agreed to participation with completing the CPR curriculum. In the classification of group in participants, the modified chest compression method was called as smartphone group (33 people). The standardized chest compression method was called as traditional group (31 people). The common equipments in both groups were used Manikin for practice and Manikin for evaluation. In the meantime, the smartphone group for application was utilized Android and iOS Operating System (OS) of 2 smartphone products (G, i). The measurement period was conducted from September 25th to 26th, 2012. Data analysis was used SPSS WIN 12.0 program. As a result of research, the proper compression depth (mm) was shown the proper compression depth (p < 0.01) in traditional group (53.77 mm) compared to smartphone group (48.35 mm). Even the proper chest compression (%) was formed suitably (p < 0.05) in traditional group (73.96%) more than smartphone group (60.51%). As for the awareness of chest compression accuracy, the traditional group (3.83 points) had the higher awareness of chest compression accuracy (p < 0.001) than the smartphone group (2.32 points). In the questionnaire that was additionally carried out 1 question only in smartphone group, the modified chest compression method with the use of smartphone had the high negative reason in rescuer for occurrence of hand back pain (48.5%) and unstable posture (21.2%). Keywords: Cardiopulmonary resuscitation, smartphone, application, chest compression
1. Introduction KACPR [1] said that the role of bystanders is crucial in the treatment of cardiac arrest. According to the report of Choi [2] on the primary implications of cardinal arrest that occurs out of hospital during five years (2006 to 2010), 44.3% of patients were not observed when having cardinal arrest while ∗ Address for correspondence: Sang-Sub Park, Graduate School of Pharmacy, Korea University, 2511, Sejong-ro, Jochiwoneup, Sejong-si, 339-700, Korea. E-mail: [email protected].
c 2014 – IOS Press and the authors. All rights reserved 0928-7329/14/$27.50
352
S.-S. Park / Comparison of chest compression quality between two groups Table 1 Characteristics of subjects Gender
Male Female
Smartphone group (n: 33) 18 (54.5) 15 (45.5)
Traditional group (n: 31) 15 (48.4) 16 (51.6)
χ2 0.243
p-value 0.622
38.2% was witnessed. During the period, only 2.1% of the observed patients of cardinal arrest received Cardio Pulmonary Resuscitation (CPR). According to the analysis attempted by Hollenberg et al. [3] on the patients who had cardinal patients out of hospital from 1992 to 2005, the percentages of patients who were witnessed of cardinal arrest were similar in 1992 and 2005. Meanwhile, the percentage of the patients not observed declined from 35% in 1992 to 29.0% in 2005. And the performance of CPR rose from 31.0% in 1992 to 50.0% in 2005. The different figures in CPR performance between Choi [2] and Hollenberg et al. [3] seem to be attributable to the difference in social and environmental factors. An emergency guideline of cardinal arrest was simplified to take more active CRP performance at the witness of patients having cardinal arrest. The simplified guideline, which was recommended by American Heart Association, AHA [4], changed the procedure of CPR from Airway-Breathing-Chest compression to Chest compression-Airway-Breathing. It also omitted look, listen, and feel from the algorithm of checking breath. It recommended hands-only CPR instead of mouth-to-mouth resuscitation in case that a CPR provider, regardless of his experience with or without CPR training, is reluctant to apply artificial respiration (mouth-to-mouth resuscitation). The guideline recommended that chest be compressed at least 5 cm deep and 100 times a minute. Recently, Smartphone is widely used to disseminate CPR. ZOLL [5] and Kovic [6] developed Pocket CPR and CPR PRO App, respectively. In addition, Koo et al. [7], NEMA [8], and MW [9] developed applications that provide information of emergency response procedure and emergent medical treatment. Pyo at el. [10] said that Smartphone application can feed back instantly, not limited to time and place, and provides users with self-educating environment. Lee [11] opinioned that Smartphone has limitless expandability using Operating System like PC as long as software needed is installed in the device. In this respect, the authors of this study attempted to examine the difference in quality between modified chest compression procedure using Smartphone and the standardized method. It aims to provide a substantial contribution to the training and education of CPR technique. 2. Methods 2.1. Characteristics of subjects Seventy participants were randomly selected from those who had completed CPR training course before and consented to the participation in the experiment. They were divided into two groups. One was Smartphone group (35) and the other was Traditional group (35). 6 participants were dropped out, so 64 participants completed this test (smartphone group of 33 and Traditional group of 31). The profiles of the participants are shown in Table 1. This experiment was conducted for two days, from the 25th to 26th of September, 2012. 2.2. Measurement This study intended to compare the difference of quality in chest compression between Smartphonebased modified method and standardized method. To do so, smartphones and manikins were used as
S.-S. Park / Comparison of chest compression quality between two groups
353
measurement tools. The participants were divided into two groups and explained of the procedures and method. They were not allowed to share their evaluations. Smartphone group, holding a smartphone between hands, performed modified chest compression. They used 5 G smartphone of S company and 5 i smartphone of A company. G smartphone is operated in Android OS while i smartphone runs in iOS. The reason why only two kinds of smartphone were used in the experiment was that they were most widely used. In addition, they were chosen because the size of smartphone is different by operating system. The participants were asked to choose a smartphone to use in order. ZOLL[5]’s Pocket CPR was used for CPR application program. The application was easily accessible and compatible to both Android and iOS. ZOLL[5]’s Pocket CPR uses the modified CPR chest compression method. The user holds a smartphone between hands watching the screen of the Smartphone while performing chest compression. The screen consists of visual and aural components such as “compression part”, “compression depth (graph)”, “Start CPR (voice)” and “Compression speed (sound)”. It has been recently upgraded and it now has a phrase “Music” and “Push Harder” instead of “Knock” sound. Traditional method group followed hand positions as suggested in the standardized guideline. They locked hands on the part of the body to be compressed and pressed them down. Figure 1 shows the hand positions of the two groups. 2.3. Measuring equipment and quality assessment items The two groups practiced chest compression on the same kind of manikin (Little AnneTM of Laerdal (Norway). Resusci Anne w/ Skillreporter System (Laerdal, Norway) was used at the final CPR performance. Assessment criteria followed 2010 Guideline [1,4] – 5 cycles of 30 times of chest compression and 2 times of artificial respirations. However, only chest compression was applied in quality assessment. Since the application program of the smartphone group only consisted of ’hands-only CPR’, artificial respiration was excluded. Measurement was carried out in a lecture room. The quality assessment items of chest compression consisted of ‘proper compression depth (mm)’, ‘average compression velocity (time/min)’, ‘accuracy of chest compression (%)’, ‘too week (time)’, poor compression site (time)’, ‘positioned too below (time)’ and ‘poor recoil (time)’. 2.4. Questionnaire The author of this study developed questionnaire (2 items). One was accuracy awareness of chest compression (5-point Likert scale), which was applied to both groups. Higher point means higher accuracy awareness of chest compression. The other was applied only to smartphone group to know how the method of the group had impact on chest compression. The questionnaires were distributed after both groups completed the final CPR performance and were asked to fill it in. The procedure is shown in Fig. 2. 2.5. Analytical method This study used SPSS 12.0 for Window. Chi-squared analysis, mean, standard deviation, Wilcoxon signed rank test, Mann-Whitney U test were employed. Significance level was set at p < 0.05.
354
S.-S. Park / Comparison of chest compression quality between two groups
Smartphone Group
Traditional Group
Fig. 1. Chest compression posture of two groups. (Colours are visible in the online version of the article; http://dx.doi.org/ 10.3233/THC-140791)
Selection of subjects (n=70)
↓
↓
Smartphone Group (n=35)
↓
Traditional Group (n=35):
↓
Non participation (2 People) Smartphone Group (n=33)
Non participation (4 People)
Traditional Group (n=31)
↓
↓
Prior practice (2 times): Little AnneTM (Leardal Co.): 3 products.
Prior practice (2 times): Little AnneTM (Leardal Co.): 3 products.
↓
↓
Final: 30 vs 2 (5 cycles): Resusci Anne w/ Skillreporter ( טLeardal Co.): 2 products. Smartphone (G product. S Co., i product. A Co.)
Final: 30 vs 2 (5 cycles): Resusci Anne w/ Skillreporter ( טLeardal Co.): 2 products.
↓ Answer to questionnaire (2 items)
↓ Answer to questionnaire (1 item)
Fig. 2. Research procedure.
3. Result 3.1. A comparison of chest compression quality between two groups Table 2 shows the comparison of chest compression quality of smartphone and traditional method group. For proper compression depth, traditional group turned out to have performed more proper compression (53.77 mm) than smartphone group (48.35 mm). The difference was statistically significant (p < 0.01). In the accuracy of chest compression, traditional method group was more accurate (73.96%) than smartphone group (60.51%). The difference was statistically significant (p < 0.05). Two groups didn’t show statistically significant difference for the rest items.
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Table 2 A comparison of chest compression quality between two groups
Chest compression
∗
Proper compression depth (mm) Average compression velocity (time/min) Chest compression (%) Too weak (time) Poor compression site (time) Positioned too below (time) Poor recoil (time)
Smartphone group Mean ± SD 48.35 ± 9.23 108.09 ± 8.86 60.51 ± 40.00 48.83 ± 60.41 15.83 ± 39.96 0.00 ± 0.00 0.61 ± 2.70
Traditional group Mean ± SD 53.77 ± 4.41 114.25 ± 7.92 73.96 ± 30.92 33.67 ± 48.92 8.09 ± 22.35 0.80 ± 4.49 0.70 ± 2.63
p-value 0.002∗∗ 0.007∗∗ 0.015∗ 0.130 0.490 0.317 0.856
p < 0.05, ∗∗ p < 0.01.
3.2. A comparison of chest compression quality according to gender Table 3 shows the comparison of chest compression quality by Gender. For the accuracy of chest compression, males of smartphone group (72.64%) were more accurate than females of smartphone group (44.73%). The difference was statistically significant (p < 0.05). Like smartphone group, males of traditional method group were more accurate (88.33%) than females of traditional group (60.50%). The difference was statistically significant (p < 0.05). As far as ‘too weak (time)’ was concerned, females of smartphone group (80.33 times) compressed chest more weakly than males of smartphone group (24.66 times). The difference was statistically significant (p < 0.05). Meanwhile, traditional group didn’t show statistically significant difference in weak compression by Gender. Males of smartphone group (21.00 times) performed chest compression on poor site than females of smartphone group (7.53 times), but the difference wasn’t statistically significant (p < 0.05). Groups by Gender didn’t show statistically significant difference in the rest items. 3.3. Accuracy awareness of chest compression Table 4 shows the result of accuracy awareness of chest compression by group. Traditional method group (3.83) was more aware that Smartphone-based chest compression was helpful than Smartphone group (2.32). The difference was statistically significant (p < 0.001). 3.4. Effectiveness of smartphone This question was asked only to Smartphone group. The participants in this group had more negative opinion than positive on the use of smartphone for chest compression. The most reasons for the negativity included hand back pain (48.5%) and unstable posture (21.25%), which were followed by slip (18.2%), inaccurate compression site (6.1%), and dispersion concentration (6.1%) (Fig. 3).
4. Discussion In the two-group comparison, traditional group performed more quality chest compression than smartphone group. For the accuracy awareness of chest compression, traditional method group showed higher awareness. Smartphone group had more negative awareness due to pain in hands and unstable posture.
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S.-S. Park / Comparison of chest compression quality between two groups Table 3 A comparison of chest compression quality according to gender Smartphone group Male Female Mean ± SD Mean ± SD 51.22 ± 8.01 45.00 ± 9.09
Chest Proper compression compression depth (mm) Average velocity 108.00 ± 8.49 107.66 ± 9.59 (time/min) Chest compression 72.61 ± 34.31 44.73 ± 40.04 (%) Too weak (time) 24.66 ± 37.54 80.33 ± 66.45 Poor compression 21.00 ± 50.05 7.53 ± 17.54 site (time) Positioned too 0.00 ± 0.00 0.00 ± 0.00 below (time) Poor recoil (time) 1.00 ± 3.51 0.13 ± 0.51 ∗
Pvalue 0.055
Traditional group Male Female Mean ± SD Mean ± SD 55.00 ± 3.50 52.62 ± 4.96
0.841 113.33 ± 6.45
115.12 ± 9.22
Pvalue 0.158 0.476
0.048∗
88.33 ± 18.06
60.50 ± 34.75
0.019∗
0.019∗ 0.704
15.00 ± 27.69 0.53 ± 2.06
51.18 ± 58.27 15.18 ± 29.74
0.200 0.017∗
1.000
0.00 ± 0.00
1.56 ± 6.25
0.333
0.246
1.33 ± 3.73
0.12 ± 0.34
0.497
p < 0.05. Table 4 Accuracy awareness of chest compression Awareness of accuracy Gender
∗∗∗
Male Female
M ± SD p-value Mean ± SD Mean ± SD p-value
Smartphone group Traditional group 2.32 ± 1.01 3.83 ± 0.68 0.000∗∗∗ 2.50 ± 0.78 4.07 ± 0.70 2.20 ± 1.20 3.62 ± 0.61 0.224 0.078
p < 0.001.
Fig. 3. Effectiveness of smartphone.
The experiment showed that standardized method was more effective than smartphone-based modified chest compression as a whole. Aufderheide et al. [12] reported in the comparison of a standard hand position and 3 other compression methods (Two-Finger Fulcrum Technique, Five-Finger Fulcrum Technique, Hands-Off Technique) that the standard chest compression was more proper. Also, Skogvoll and Wik [13] didn’t show, in the comparison between standardized chest compression method and ACD (Active Compression – Decompression) CardioPump , which was a chest compressor of which upper part was attached with a handler and lower part was shaped like a plate, that ACD CardioPump was better than standardized chest
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compression method. The question why the modified chest compression methods above were not efficient seem to be answered by the different hand position, as mentioned in the Guideline [1] – “CPR can’t be varied by individual or CPR provider; CPR should be standardized to revive person with cardinal arrest; the survival rate of cardinal arrest patients can improve by standardized CPR procedure”. On the other hand, ZOLL [5,6] introduced smartphone-based modified chest compression method. ZOLL [5,6] introduced Pocket CPR , and CPR PRO App. respectively, exclusively for CPR education and training. However, the hand position and posture (holding smartphone between hands) instructed in those programs are different from those in the Guideline. Non-compliance with the directions of the Guideline or use of modified chest compression method based on smartphone can cause inaccuracy in compression depth and speed due to the pain in hands and lack of positional stability. In addition, compression should be given on chest with vertically straightened arms (elbows). However, the modified chest compression method allows arms to bend or fold, which results in inaccuracy in compression. Positional instability can cause fractures of the ribs and breastbones, liver damage, epicardial and lung bleeding [14–16]. Therefore, smartphone-based chest compression requires a special caution. In the meantime, Kovic [6], Kovic and Lulic [17] introduced a chest compression method (CPR PRO Cradlea) with smartphone held in both handlers, not held in hands, while watching the screen of the device. In addition, Kovic [6] introduced ’CPR Prompts’, which is a chest compression method using smartphone screen lying beside a patient just like Visual Feedback device. ZOLL [5] also developed an iOS-exclusive device by which Smartphone is fixed on a backhand. This device runs in “Strap device on top of hand” mode, allowing a CPR provider to watch the screen of smartphone while performing CPR. Among those products mentioned above, CPR Prompts and “Strap device on top of hand” follow the standardized chest compression procedure. Namely, they use Smartphone in various ways, but they conform to standard CPR method. Pyo et al. [10] said that learning through smartphone was a way to increase interest. Accordingly, Koo at el. [7], NEMA [8] and MW [9] developed smartphone applications that help efficiently cope with emergency through learning first aid including CPR in daily life. Their applications are not modified chest compression methods but pre-training for the standardized chest compression (self-learner puts smartphone on a chest and practice chest compression). However, chest compression method with smartphone on a chest has some limitations. First, trainees may learn wrong method of standard chest compression during education and training. Second, it is doubted that smartphone-on-chest compression can be utilized in real situation as efficiently as or better than standardized chest compression method. Third, the method may cause pain in hands and (hands’) positional stability. Therefore, it is considered that smartphone-on-chest compression method is not proper and less efficient than standardized traditional method. It is desirable that smartphone should be used a pre-learning tool for standardized chest compression method. This study has some limitations. First it limited the use of smartphone to only 2 products. Second, smartphones are varied in size by OS. Third, the experiment was done on limited number of samples. Fourth, the measurement was based on short term. Fifth, it used manikin, which is far from real situation. As a result, discretion is required in generalizing the findings of the study. Based on the findings, the standardized traditional chest compression method is considered to be likely to be necessarily maintained in the skills acquirement and the skills education compared to the modified chest compression method with the use of smartphone.
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5. Conclusions The result of the study demonstrated that standardized chest compression method in accordance with the Guideline is more appropriate for skill education and training. And it is better that smartphone is used as prerequisite learning for standardized chest compression method. More diverse researches are expected on smartphone-based chest compression methods. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
[13] [14] [15] [16] [17]
KACPR. 2011 Korean guideline for CPR ECC, www.kacpr.org. 2011. Choi JA. Result of Out-of-Hospital Cardiac Arrest Surveillance, 2006-2010. Public Health Weekly Report. http://www.cdc.go.kr. 2012; 5(41): 777-782. Hollenberg J, Herlitz J, Lindqvist J, Riva G, Bohm K, Rosenqvist M, Svensson L. Improved Survival After Out-ofHospital Cardiac Arrest Is Associated With an Increase in Proportion of Emergency Crew-Witnessed Cases and Bystander Cardiopulmonary Resuscitation. J of Circulation. 2008; 118(4): 389-396. American Heart Association(AHA). 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science, Part 5: Adult Basic Life Support. http://www.americanheart.org, 2010 ZOLL. PocketCPR Real-time CPR Feedback. http://www.pocketcpr.com, 2011. Kovic I. CPR PRO App. Ivor Medical. http://www.ivormedical.com, 2010. Koo MJ, Seo JM, Chang YH, Han WC, Baek YT, Pyo SB, Lim HJ. A Study of Coping Ways in Emergency Situations Using SmartPhones. J of Korean Society Computer Information, Winter Conference. 2012; 20(1): 87-90. National Emergency Management Agency(NEMA). Coping method for emergency situations. http://www.nema.go.kr, https://play.google.com/store/apps/details?id=com.fantalog.FirstAid&feature=search_result#?t=W10. 2010. Ministry for Health(MW). Emergency medical information provided. http://www.mw.go.kr, https://play.google.com/ store/apps/details?id=kr.go.mw&feature=search_result#?t=W10. 2012. Pyo MY, Kim JY, Sohn JO, Lee ES, Kim HS, Kim KO, Park HJ, Kim MJ, An GH, Yang JR, Yu JH, Kim YA, Kim HJ, Choi MN. The Effects of an Advanced Cardiac Life Support Training via Smartphone’s Simulation Application on Nurses’ Knowledge and Learning Satisfaction. J of Korean Clinical Nursing Research, 2012; 18(2): 228-238. Lee SM., Han MS, Park JS. A Research on the Analysis of Inhibiting Factors In Using Smartphones and the Measure of Promoting the Use of Smartphones. J of Korea Safety Management & Science. 2011; 13(4): 237-245. Aufderheide TP, Pirrallo RG, Yannopoulos D, Klein JP, Briesen C von, Sparks CW, Deja KA, Conrad CJ, Kitscha DJ, Provo TA, Lurie KG. Incomplete chest wall decompression: A clinical evaluation of CPR performance by EMS personnel and assessment of alternative manual chest compression-decompression techniques. J of Resuscitation. 2005; 64(3): 353-362. Skogvoll E, Wik L. Active compression-decompression cardiopulmonary resuscitation: a population-based, prospective randomised clinical trial in out-of-hospital cardiac arrest. J of Resuscitation. 1999; 42(3): 163-172. Smekal D, Johansson J, Huzevka T, Rubertsson S. No difference in autopsy detected injuries in cardiac arrest patients treated with manual chest compressions compared with mechanical compressions with the LUCASTM device – A pilot study. J of Resuscitation. 2009; 80(10): 1104-1107. Lederer W, Mair D, Rabl W, Baubin M. Frequency of rib and sternum fractures associated with out-of-hospital cardiopulmonary resuscitation is underestimated by conventional chest X-ray. J of Resuscitation, 2004; 60(2): 157-162. Meron G, Kurkciyan I, Sterz F, Susani M., Domanovits H, Tobler K, Bohdjalian A, Laggner AN. Cardiopulmonary resuscitation-associated major liver injury. J of Resuscitation. 2007; 75(3): 445-453. Kovic I, Lulic I. Mobile phone in the chain of survival. J of Resuscitation. 2011; 82(6): 776-779.
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