a b s t r a c t

Objectives: The aim of the study was to compare the effect of synchronous online and face-to-face cardiopulmo- nary resuscitation (CPR) training on chest compressions quality in a manikin model.

Methods: A total of 118 fourth-year medical students participated in this study.

The participants were divided into two groups: the online synchronous teaching group and the face-to-face group. Then, the participants were further randomly distributed to 1 of 2 feedback groups: online synchronous teaching and training with Feedback devices (TF, n = 30) or without Feedback devices (TN, n = 29) and face- to-face teaching and training with feedback devices (FF, n = 30) or without feedback devices (FN, n = 29). In the FN group and FF group, instructors delivered a 45-min CPR training program and gave feedback and guidance during training on site. In the TN group and TF group, the participants were trained with an online lecture via Tencent Meeting live broadcasting. Finally, participants performed a 2-min continuous chest compression during a simulated cardiopulmonary arrest scene without the audiovisual feedback device. The outcome measures included CC depth, CC rate, proportions of appropriate depth (50-60 mm) and CC rate (100-120/ min), percentage of correct hand location position, and percentage of complete chest recoil.

Results: There was little difference in the CC quality between the synchronous online training groups and the face-to-face training groups. There was no statistically significant difference in CC quality between the TN group and FN group. There were also no statistically significant differences between the TF and FF groups in terms of correct hand position, CC depth, appropriate CC depth, complete chest recoil or CC rate. However, the FF group had a higher appropriate CC rate than the TF group (p = 0.045). In the face-to-face training groups, the AVF device group had a significantly greater CC depth, appropriate CC depth, CC rate, and appropriate CC rate. However, there was a lack of statistically significant differences in terms of correct hand position (p = 0.191) and appropriate CC depth (p = 0.123). In the synchronous online training groups, the AVF device had little effect on the CC rate (p = 0.851) and increased the appropriate CC rate, but the difference was not statistically significant (p = 0.178).

Conclusions: Synchronous online training with an AVF device would be a potential alternative approach to face- to-face chest compression training. Synchronous online training with AVF devices seems to be a suitable replace- ment for face-to-face training to offer adequate bystander CPR chest compression training.

(C) 2021 Published by Elsevier Inc.

1. Introduction

According to epidemiological data, the worldwide incidence of OHCA is 95.9 cases per 100,000 person-years [1]. After cardiopulmonary

* Corresponding authors at: Emergency Center, Hubei Clinical Research Center for Emergency and Resuscitation, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, Hubei 430071, China.

E-mail addresses: redjin@whu.edu.cn (X. Jin), doctoryanzhao@whu.edu.cn (Y. Zhao).

¹ Lian Lin and Shaozhou Ni contributed equally.

arrest, the Quality of cardiopulmonary resuscitation (CPR) directly affects survival hemodynamics and Survival and neurological outcomes [2-4]. Therefore, the ability to perform high-quality CPR has been pro- moted as central to improving survival from cardiac arrest by interna- tional practice guidelines and leading healthcare institutions [5].

Bystander CPR is a fundamental link in improving survival from OHCA. OHCA victims who received CPR from a bystander are much more likely to survive than those who did not. OHCA victims who re- ceive CPR from a bystander are much more likely to survive than those who do not receive bystander CPR [6]. Several health care

https://doi.org/10.1016/j.ajem.2021.07.009 0735-6757/(C) 2021 Published by Elsevier Inc.

institutions have called for research on innovative CPR training methods to further promote CPR skills among civilians [5,7]. Effective chest com- pression (CC) is one of the most important aspects of cardiopulmonary resuscitation. There is a growing body of literature focusing on monitor- ing and improving CPR performance in both simulated and actual events. Current evidence suggests that audiovisual feedback (AVF) de- vices can effectively improve the Quality of CPR training and skill reten- tion [8]. It is important to find better methods for teaching CPR to help potential bystanders acquire knowledge and skills.

The Covid-19 outbreak has restricted the previous classroom-based teaching environment. There is an urgent need for new teaching methods to meet normal teaching requirements. In the spring of 2020, universities around the world transformed traditional face-to-face classroom teaching into online teaching environments. Tencent Meet- ing provides an easy-to-use, free, smooth, safe and reliable cloud- based HD video conferencing solution. Many universities and colleges choose Tencent Meeting as an online teaching mode, and studies have demonstrated that the effect of online teaching in a medical molecular biology course for undergraduates majoring in pharmacy was not worse than that of traditional face-to-face classroom teaching [9]. How- ever, theoretical knowledge can be taught by Tencent Meeting, and there is no clear effect of teaching the operations of clinical skills, such as CPR. The purpose of this study was to compare the effect of the quality of training in CPR skills between Tencent Meeting training and traditional face-to-face training and to identify a better way to acquire high-quality CPR skills.

1. Methods
   1. Participants and setting

This study was a pilot randomized manikin study conducted be- tween Dec 6, 2020, and Dec 8, 2020, at the Second Clinical School, Wuhan University (Wuhan, Hubei, China). A total of 118 fourth-year medical students participated in this study. Participants whose physical disability or other health problems might affect the Quality of chest compressions were excluded. Participants’ characteristics, including age, gender, height, and weight, were recorded. The research protocol was approved by the Ethics Committee of Zhongnan Hospital, and each participant signed an informed consent form before participating (IRB number: 2020116 K).

• 1. Study design
     1. Grouping

Students were randomly assigned using a card in a sealed envelope. If “A” was on the card in the envelope, the participants were assigned to the TN group (n = 29). If “B” appeared on the card, the participants were assigned to the FN group (n = 29). If “C” appeared on the card, the participants were assigned to the TF group (n = 30). If “D” appeared on the card, the participants were assigned to the FF group (n = 30). In addition, all the instructors were blinded to the grouping allocation, and each instructor guided only one group of participants.

• • 1. Training

In the FN group and FF group, all the students were trained using the traditional face-to-face method. The instructors possessed AHA- certified Basic Life Support certification. The instructors delivered 45-min CPR training, which included the following: [1] Check respon- siveness, yell for help, activate the emergency response system, make an emergency call for help and send for an AED; [2] Check breathing and pulse (breathing and pulse check can be performed sim- ultaneously) for at least 5 s and no more than 10 s; and [3] CPR in- struction and practice. The instructor emphasized high-quality CPR characteristics according to the 2015 AHA CPR guidelines, such as

adequate CC depth, CC rate, complete chest recoil, and correct hand position.

In the TN group and TF group, all the students were trained by Tencent Meeting synchronous online live broadcasting. Tencent Meeting is a new type of smart online video conferencing solution that provides easy-to-use, free, steady, secure and reliable cloud-based high-definition videoconferencing tool. The participants received CPR training via an online lecture and video shown by BLS instructors.

• • 1. CPR practice

All the participants practiced on an adult Laerdal Resusci Anne QCPR torso manikin (Laerdal China Ltd., Hangzhou, China). SimPad PLUS was connected to the QCPR manikin and used as the AVF device in this study. The Laerdal SimPad PLUS is a tablet that automatically records the fol- lowing variables: CC depth, CC rate, percentage of appropriate CC depth and CC rate, percentage of compressions with complete chest re- coil, and percentage of correct hand location position. SimPad PLUS pro- vided audiovisual feedback based on direct estimates of the current parameters of CPR and their real-time visualization through a tablet interface. Since we performed CC-only CPR in this study, only those pa- rameters related to compression were evaluated for quality evaluation. The study protocol is summarized in Fig. 1. Each instructor was assigned 8 to 10 participants, and all the instructors were blinded to the group- ing. During training, the instructors ensured that each participant performed at least 5 CC cycles (2 min/cycle) on manikins.

In the FN group and FF group, the instructor provided performance- related feedback and guidance based on the participants’ behavior during training. In the TN group and TF group, participants’ practice processes were broadcast live to the instructor, and then, the instructor transmitted training feedback information and guidance to participants via Tencent Meeting. There was one manikin and 15 participants in each classroom. Two cameras (SONY AX60) were laid on the side of the man- ikin’s foot and left-hand side. Each manikin was equipped with a study assistant to keep the study going.

• 1. Outcome measures

Finally, participants performed a 2-min continuous CC without the AVF device in the simulated cardiopulmonary arrest scene. technical performance data were recorded by the Laerdal Computerized Skill Reporting System. The following variables were recorded mechanically by Laerdal SimPad PLUS: CC rate, CC depth, percentage of appropriate CC rate (100-120/min), and percentage of appropriate depth (50-60 mm). The appropriate CC depth and rate, percentage of appropriate CC depth and rate, correct hand position and complete chest recoil were taken from the 2015 American Heart Association (AHA) guidelines.

• 1. Statistical analysis

We assessed the normal distribution of continuous variables and re- port the results as the mean +- SD. Continuous data were compared using Student’s t-test or variance and least-significant difference tests. Categorical variables were reported as numbers (%) and compared using ?² or Fisher’s exact tests. A p-value of <0.05 was considered statis- tically significant. The data were analyzed using commercial software (SPSS version 19, IBM Corporation, New York, USA).

1. Results
   1. Participant flow and recruitment

A total of 118 participants provided informed consent (Fig. 1). Partic- ipants were randomly assigned to the TN group (n = 29), FN group (n = 29), TF group (n = 30) and FF group (n = 30) and then received

Assessed for eligibility (n=118)

0 Initial exclusions

118 participants randomized

Face-to-face training groups

(n=59)

Synchronous online groups

(n=59)

With feedback device during

trainign (FF=30)

Without feedback device

during training (FN=29)

With feedback device during

training (TF=30)

3 participants excluded due

examization

2 participants excluded due

1 participants excluded due

to missing data

0 participants excluded

26 participants analyzed

27 participants analyzed

29 participants analyzed

30 participants analyze

Without feedback device during training (TN=29)

Fig. 1. TN: Tencent Meeting training without feedback device; FN: face-to-face training without feedback device; TF: Tencent Meeting training with feedback device; FF: face-to-face with feedback device.

CPR training. In the TN group, 3 participants quit the study due to other curriculum examinations, and 26 participants finished the study. In the TF group, 2 participants quit the study because of physical reasons, and 27 participants finished the study. In the TF group, 1 participant was ex- cluded due to missing data, and 29 participants were analyzed. No one was excluded in the FF group.

• 1. Baseline data

There were four groups of 112 students who finished the CPR course and test. Table 1 summarizes the demographic data of these four groups of participants. There were no significant differences in terms of gender, weight, height or BMI between the four groups (p > 0.05), but there was a statistically significant difference in participants’ age (p = 0.026).

The time gaps from CPR training to the CPA scenario were not signifi- cantly different between the four groups (p > 0.05).

• 1. CC quality comparison between synchronous online training groups and face-to-face groups

The CC quality comparisons between synchronous online training groups and face-to-face groups are summarized in Table 2. There was no statistically significant difference between the TN group and FN group. There was also no statistically significant difference between the TF and FF groups in terms of correct hand position, CC depth, appro- priate CC depth, complete chest recoil and CC rate. However, the FF group had a significantly higher percentage of appropriate CC than the TF group (p = 0.045). There was little difference between these two training methods.

Table 1

Characteristics of participants.

Characteristic	TN	TN	FF	TF	P
Number Gender	26	27	29	30	0.926
Man	13(50%)	15(55.56%)	15(51.72%)	14(46.67)
Woman	13(50%)	12(44.44%)	14(48.28%)	16(53.33%)
Age	21.19 +- 0.49	21.15 +- 0.70	21.41 +- 0.87	21.76 +- 0.97	0.026
Height(cm)	168.75 +- 7.93	170.29 +- 9.69	168.41 +- 6.22	169.13 +- 7.18	0.822
Weight(kg)	59.04 +- 12.48	60.94 +- 13.66	56.81 +- 9.71	62.13 +- 11.29	0.081
BMI	20.56 +- 3.18	20.78 +- 2.95	19.94 +- 2.47	21.61 +- 2.99	0.485

TN: Tencent Meeting training without feedback device; FN: face-to-face training without feedback device; TF: Tencent Meeting training with feedback device; FF: face-to-face with feed- back device; Data are expressed as number (percentage) or mean +- SD.

Table 2

Chest Compression quality comparison between Tencent Meeting training groups and face-to-face groups.

	TN	FN	p	TF	FF	p
Correct hand position (%)	86.41 +- 28.68	90.88 +- 15.51	0.339	97.62 +- 4.84	96.87 +- 15.51	0.865
CC depth(mm)	52.00 +- 7.79	55.17 +- 4.23	0.96	55.17 +- 4.23	55.43 +- 4.68	0.850
Appropriate CC depth (%)	61.15 +- 42.63	71.86 +- 18.78	0.178	82.21 +- 24.78	83.70 +- 25.94	0.842
Complete chest recoil (%)	87.03 +- 18.66	84.59 +- 13.39	0.525	94.97 +- 10.57	93.63 +- 12.46	0.714
CC rate (cpm)	111.19 +- 11.75	104.26 +- 22.99	0.077	110.48 +- 10.30	113.23 +- 6.86	0.455
Appropriate CC rate (%)	64.12 +- 26.35	69.07 +- 29.48	0.447	72.76 +- 20.65	84.66 +- 17.00	0.045

Appropriate CC depth and rate, percentage of appropriate CC depth and rate, correct hand position and complete chest recoil were confirmed according to the 2015 American Heart As- sociation (AHA) guidelines.

CC = chest compression.

TN: Tencent Meeting training without feedback device; FN: face-to-face training without feedback device; TF: Tencent Meeting training with feedback device; FF: faceto-face with feed- back device.

Data are expressed as mean +- SD.

• 1. CC quality comparison with or without a feedback device in synchro- nous online training groups and face-to-face training groups

CC quality comparisons with or without a feedback device in the synchronous online training group and face-to-face training group are summarized in Table 3. In general, the AVF device improved CC quality in both the synchronous online training group and the face-to-face training group. In the face-to-face training group, the AVF device led to a significant improvement in CC depth, appropriate CC depth, CC rate, and appropriate CC rate. However, there was a lack of significance in the correct hand position (p = 0.191) and appropriate CC depth (p = 0.123). In the synchronous online training group, the AVF device had lit- tle effect on the CC rate (p = 0.851) and increased the appropriate CC rate, but the difference was not statistically significant (p = 0.178).

1. Discussion

Our results showed that synchronous online training was not infe- rior to traditional face-to-face training in terms of CC quality. With the help of AVF equipment, at least 80% of participants who participated in synchronous online training met the depth requirements recognized by the AHA guidelines, and at least 70% of the participants met the speed requirements recognized by the AHA guidelines. In addition, the pro- portions of complete chest recoil and correct hand position were signif- icantly higher with the help of the AVF device. This suggests that synchronous online training with an AVF device would be a potential al- ternative approach to face-to-face training to provide adequate chest compressions.

The COVID-19 outbreak has greatly facilitated the use of online teaching in Chinese schools. Although our university has resumed on- campus teaching, we are unsure how long the coronavirus crisis will last, and we need to further explore new teaching models to overcome the effect of the coronavirus crisis. Experts warn that the SARS-CoV-2 panic will affect education worldwide for a long period of time. Using

their online teaching experience, universities should plan different ways to address the effects of the coronavirus on education and main- tain normal teaching programs. Our study showed that with the AVF de- vice during CPR practice, the quality of synchronous online training showed little difference from that of face-to-face training. This makes online CPR skill teaching possible. Synchronous online training was not worse than traditional face-to-face training in terms of chest com- pression quality. This suggests that synchronous online training with an AVF device would be a potential alternative approach to face-to- face training to provide adequate chest compression instruction.

According to the recommendations of the 2015 Cardiopulmonary Resuscitation guidelines, rescuers should compress the chest with the correct hand position, adequate depth, and rate and complete chest re- coil and minimize the frequency and duration of interruptions [10]. It is even difficult for experienced instructors to assess whether rescuers’ CPR met the requirements recognized by the guide [11]. In our study, synchronous online training with a feedback device group showed a high level of CPR CC quality compared to the group without a feedback device. We derived similar conclusions to some other studies, which proved that the application of feedback devices could improve CPR quality [12,13]. This study combined instructor feedback and an AVF de- vice, and providing direct visual feedback to providers or verbal feed- back provided via instructors based on an AVF device significantly improved CC performance by fourth-year medical students during sim- ulated resuscitation compared with traditional, instructor-based feed- back alone.

In the present study, the AVF device improved the CC depth in both the synchronous online group and the face-to-face training group. How- ever, in this study, the feedback device improved the appropriate CC depth of both groups, but there was no statistically significant difference in the face-to-face training group (p = 0.123). In contrast to our study, a recently reported study [14] found that a feedback device had no effect on compression depth. AVF devices had no effect on the CC rate and en- hanced the appropriate CC rate in the synchronous online training

Table 3

chest compression quality comparison with or without feedback device in Tencent Meeting training groups and face-to-face group.

	FN	FF	p	TN	TF	p
Correct hand position (%)	90.88 +- 15.51	96.87 +- 15.51	0.191	86.41 +- 28.68	97.62 +- 4.84	0.015
CC depth(mm)	51.93 +- 3.81	55.43 +- 4.68	0.014	52.00 +- 7.79	55.17 +- 4.23	0.029
Appropriate CC depth (%)	71.86 +- 18.78	83.70 +- 25.94	0.123	61.15 +- 42.63	82.21 +- 24.78	0.008
Complete chest recoil (%)	84.59 +- 13.39	93.63 +- 12.46	0.016	87.03 +- 18.66	94.97 +- 10.57	0.038
CC rate (cpm)	104.26 +- 22.99	113.23 +- 6.86	0.018	111.19 +- 11.75	110.48 +- 10.30	0.851
Appropriate CC rate (%)	69.07 +- 29.48	84.66 +- 17.00	0.014	64.12 +- 26.35	72.76 +- 20.65	0.178

Appropriate CC depth and rate, percentage of appropriate CC depth and rate, correct hand position and complete chest recoil were confirmed according to the 2015 American Heart As- sociation (AHA) guidelines.

CC = chest compression.

FN: face-to-face training without feedback device; FF: faceto-face with feedback device; TN: Tencent Meeting training without feedback device; TF: Tencent Meeting training with feed- back device.

Data are expressed as mean +- SD.

group, which was consistent with our previous research [8]. In the face- to-face group, there was a significantly positive change in the appropri- ate CC rate. However, compared to the face-to-face group, there are some shortcomings in the appropriate CC rate of the synchronous on- line training group that need to be further improved. There was no dif- ference in terms of appropriate correct hand position and complete chest recoil between the two training methods. With the application of the AVF device, both the synchronous online training group and face-to-face training group had better performance in terms of appro- priate correct hand position and complete chest recoil, which was con- sistent with previous research [8,15]. The Laerdal QCPR mannequins and SimPad PLUS tablets we used as AVF devices in this study are ex- pensive. Therefore, students can read the current CPR parameters and immediately take corrective actions to promote better consistency with the guidelines.

• 1. Limitations

There are three main limitations of this study. A previous study showed that compression-only CPR training alone seems to help by- standers maintain CPR skills better than traditional CPR training [16]. Therefore, in the present study, we only observed the outcome of CC without ventilation. Although our results effectively demonstrated the effects of synchronous online training and face-to-face training on CC Skill acquisition, we only observed the outcome of CC. The effects of these training methods on other CPR skills, including the effect of venti- lation, identification of cardiac arrest, and application of an automated external defibrillator, are unclear. Second, several days passed between CPR training and the cardiopulmonary arrest scenario, and the delay be- tween CPR training and the provision of CPR is unpredictable in a real clinical environment. Long-term retention of CC quality trained by the two training methods requires further investigation. Although we found that the overall CC quality in both training groups was acceptable, the CPR quality in real life and the corresponding impact on patient prognosis were unclear. Last, synchronous online training may be de- pendent on network speed and availability, which may affect CPR teach- ing and training.

1. Conclusion

There was no significant difference between the synchronous online training group and face-to-face training groups in terms of chest com- pression hand position, depth, recoil, and rate when utilizing feedback devices. There was no significant difference between the synchronous online training group and face-to-face training groups in terms of chest compression hand position, depth, recoil, and rate when utilizing feedback devices in a manikin model. This indicates that synchronous online compression training with an AVF device seems to be an accept- able alternative for face-to-face training. Further study is needed to de- termine the educational impact on CPR skills of this online training.

Funding

None.

Declaration of Competing Interest

None.

Acknowledgments

We would like to thank all the participants who made this study possible.

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