Challenges in Basic Life Support and Automated External Debrillator Training of Deaf People

Basic life support (BLS) with the use of an automated external debrillator (AED) is a fundamental link to a successful chain of survival of patients with cardiac arrest. However, the BLS protocol is not tailored for deaf people who encounter many challenges during BLS training. A and a on a and and quantitative data on and Results


Abstract Background
Basic life support (BLS) with the use of an automated external de brillator (AED) is a fundamental link to a successful chain of survival of patients with cardiac arrest. However, the BLS protocol is not tailored for deaf people who encounter many challenges during BLS training.

Methods
After an ergonomic analysis and modi cations of the BLS and AED protocol, a practical course was conducted. A pre-course BLS and AED knowledge was tested with a questionnaire. After the course, each participant practically solved a cardiac arrest scenario on a manikin and qualitative and quantitative data on BLS and AED performance were collected with a modi ed Cardiff test and the QCPR mobile application. Results of the knowledge test and performance were presented with frequencies and correlations between pre-and post-course BLS and AED knowledge and performance were analyzed and presented with Spearman's rho.
Results 51 deaf volunteers from seven Slovenian societies for deaf people participated in the study. Results on the pre-course knowledge test were poor (3.5 points out of 10). BLS performance according to the modi ed Cardiff test post-course was also poor: 52.9 % of the participants used a safe approach, 58.8 % checked responsiveness and 51.0 % sent a text message to the rescue service. Only 43.1 % of them opened the airway and 49.0% checked initial breathing. 80.4% of the deaf rescuers performed chest compressions on the lower half of the sternum but only 52.9 % of them compressed with adequate depth.
According to the QCPR application the best performance was achieved with the compression score of 61.1 % and ow fraction 74.9%.

Conclusions
This study shows that a more comprehensive and assidiuous approach is needed for effective BLS and AED training courses for deaf people.

Background
Sudden cardiac arrest is one of the leading causes of death in Europe [1]. The recommended treatment for cardiac arrest is immediate basic life support procedures (BLS) [2]. Teaching lay people BLS is a fundamental link to a successful chain of survival of patients with cardiac arrest [3]. However, guidelines for BLS are not tailored for deaf people. There are several steps that deaf people have di culties with or cannot perform: listening to check initial breathing, calling 112 or using an automated external de brillator (AED) with voice instructions [4]. The use of an AED is one of the basic resuscitation procedures as it can be used to stop malignant arrhythmias [5], but the device itself is often not adapted for use by the deaf people, as it provides only voice instructions for use. The AED must be equipped with pictorial instructions to shorten the time to successful de brillation [6].
Most deaf people use sign language which is a unique language with its own grammar and syntax and differs markedly from the mother tongue and is not its gestured representation [7]. Therefore, they are not uent in the language of the surroundings and consequently, low level of reading comprehension in people with hearing loss has been observed [8]. In addition, health literacy and knowledge weaknesses of the deaf were described [9][10][11]. They are not familiar with the symptoms [9] and vocabulary regarding most common cardiovascular health issues [12]. Therefore, both deaf trainees and their instructors face many challenges during BLS training, from communication issues to inadequate BLS protocols. In this study, we aimed at appraising the distinctions between deaf and general population regarding the BLS and AED protocol and speci c hindrances by deaf during the BLS training. Based on those observations we aimed to propose measures to improve BLS and AED courses for deaf people.

Study design
Study design included two steps. In the rst step, occupational medicine specialist (Z.Š.) did an ergonomic analysis of the BLS and AED protocol of the latest European resuscitation council guidelines [2]. Based on observations, the following modi cations were proposed to enable successful BLS and AED training of deaf people: BREATHING -look and feel for normal breathing; UNRESPONSIVE AND NOT BREATHING NORMALLY -ask a helper to call the emergency services (112) if possible, otherwise activate them yourself by sending a text message or informing call center for deaf people and ask them to call 112; WHEN AED ARRIVES-switch on the AED, put it in the visual eld and follow the visual prompts.
In the second step, a practical course for interested deaf volunteers was conducted. In each class there were a maximum of 10 participants, 5 per instructor. At the beginning of the course, each participant lled out a pre-course BLS and AED knowledge test [13]. . The Cardiff test was modi ed to match the modi cations of the BLS and AED protocol for deaf people. Items of both instruments were collected together on a joint checklist. Incorrect performance of the item's task was scored 1 point, whereas partially correct or correct performance was scored with more points (ranging from 2 to 4). In additional analysis every item was graded only as correct or incorrect performance. BLS performance was evaluated by one of the two instructors (V.V. and Z.Š.).

Sample
We contacted all 13 Slovenian societies for deaf people by email and invited them to participate in the study. Deafness was de ned as loss of hearing more than 95% by Fowler and using sign language for communication. 51 volunteers from 7 societies for deaf people participated in the study in the period from 30.1.2019 to 15.1.2020 (Table 1).

Pre-course
The mean sum of correct answers on the pre-course knowledge test was 3,51 (± 2,22 standard deviation) with a minimum and maximum score of 0 and 8 out of 10, respectively. Percentages of correct answers for each question are presented in Table 2.  (20) 10. What is an AED (automatic external de brillator)? 29,4% (15) Post-course The mean score on the post-course modi ed Cardiff test was 42,16 (± 7,22 standard deviation) with a minimum and maximum score of 28 and 55 out of 55, respectively.
Percentages of correctly performed BLS and AED tasks are presented in Table 3. Score range, means with standard deviation, minimum and maximum scores achieved on individual BLS steps on the modi ed Cardiff test are presented in Table A in Supplementary material. Step 7: Continue with BLS 72,5% (37) Qualitative assessment of BLS performance with the QCPR application is presented in Table 4. Correct performance of chest compressions and ventilations assessed by the QCPR application is shown in Table 5. Analysis of correlations between sociodemographic characteristics of the sample, pre-course knowledge of BLS and AED, and post-course BLS and AED awareness gain is presented in Table 6.

Discussion
The current study revealed that mere adjustments of the BLS and AED protocol originally designed for hearing people do not su ce for effective training of the deaf. Three crucial tasks of the BLS and AED protocol were modi ed during an ergonomical analysis: breathing check, alerting emergency services and using an AED. Similar limitations were pointed out in research by Unnikrishnan et al. [4].
In the present study, BLS and AED knowledge was tested before the course using a previously developed questionnaire for schoolchildren [13]. The results suggest that BLS knowledge by deaf is poor (an average score of 3.5/10) compared to hearing peers (7.8/10) [14] and schoolchildren (an average score of 6.0/10, data not published yet). The most incorrect answers were to the basic questions representing the core of BLS, supporting the observation of insu cient BLS and AED knowledge by deaf.
Our study showed that BLS and AED performance was also poor as scored and assessed with the modi ed Cardiff test and a manikin with feedback data. In our observation, merely half of the participants would use safe approach to the cardiac arrest victim, check responsiveness, and send a text message to the rescue service. Less than half of them would open the airway and check initial breathing or send someone for help or an AED. Regarding chest compressions, more than 80 % of participants would perform chest compressions on the correct position with nearly 53 % of them compressing one third of the diameter of the chest, but less than half of them with an adequate rate. Better results were observed by Tomasetti et al. [15] where the deaf participated in the standard American National Red Cross 4-hour course using a videocassette signed by the course instructor and achieved 40/46 points on immediate post-test score. The best performance scores yielded on the manikin in the present study were compression score and ow fraction representing "low-ow" state in cardiac arrest. Overall performance score on the manikin was reduced on account of poorer results in ventilation score. There were some score discrepancies in BLS performance between modi ed Cardiff test and feedback data from the manikin. According to the manikin data, only 23 % of participants compressed the chest with the correct average depth of 50 to 60 mm compared to 52,9 % according to the modi ed Cardiff test. This fact could be due to more accurate and sophisticated measurements made by the manikin software, whereas the depth of the compression on the modi ed Cardiff test was estimated by observation.
Using the AED can be a challenge for a deaf person, as many AEDs provide only voice prompts [16]. On the other hand, the untrained deaf rescuers are capable of using AED appropriately with visual prompts after basic training [6]. Only four participants in our study failed to attach the AED pads in correct position and eight of them forgot to turn on the AED. Nearly 80 % of deaf rescuers put the AED into the visual eld to be guided with visual instructions from the AED. They perform less successfully on the safety check and pressing the shock button. Also, Sandroni et al. described that 22 % of participants did not deliver shock. The reason was because they expected the de brillator to do it automatically [6].
Communication is the basic challenge for educators of deaf people. The major differences between BLS instructions for deaf and non-deaf are the need for a sign interpreter, the need to modify the terminology of BLS instructions and the careful explanation of terminology [17]. During the pre-test we observed an extensive effort from the sign language interpreter to explain the meaning and the purpose of the questions. This observation together with the low score on pre-test could be due to low level of reading comprehension by deaf. It was shown that an average student with hearing loss graduates from high school with reading comprehension skills at about fourth grade level [8].
In addition, there is growing evidence in the literature regarding health literacy weaknesses by deaf [9,10]. Findings from several studies indicate that deaf individuals have weaker functional health literacy and smaller found of cardiovascular health knowledge [9][10][11]. Nearly 40 % of deaf could not list any of the most common symptoms of a heart attack, while over 60 % of them could not list a single stroke symptom [9,12]. Moreover, more than one third of deaf people would not call the emergency medical number if they thought they were having a heart attack or stroke, thinking that it is not deaf-accessible [9]. This observation is similar to our study where half of the participants wouldn't send a message to the rescue service in the case of cardiac arrest although it could be activated through a text message. Although neither reading comprehension nor health literacy were analyzed in the present study, we assume that low level of both in our study group could contribute to the low scores on the pre-test.
Family conversations about family medical history and other incidental source of health knowledge are crucial for developing strong health literacy skills [11,12]. In the present study the family member working as a healthcare provider is related to better results after the course. It is likely that a healthcare worker stimulates the conversation with other family members about the medical issues and through family communication promotes healthy life style including attaining BLS skills.
De cits in reading comprehension and low level of health literacy have an impact on the BLS course.
Presentation designed for deaf adults should use simpler English grammar and vocabulary, and more visual information [11]. Our BLS course was led by a physician accompanied with a sign language interpreter from non-medical eld. It was shown that a signed interpretation appears to have been a better means of communicating BLS information to the deaf learners. The signed interpretation may eliminate poor reading comprehension as a potential barrier in learning and retention of BLS skills [15]. Changing position of the instructor during the presentation distract the deaf participants. This fact is due to the enhanced peripheral visual attention [18,19] resulting in that the deaf subjects are more susceptible to peripheral distracters [20]. We also observed that attention duration by deaf people during the course was shorter than expected (it lasted between 25-30 minutes). This observation is supported by studies reporting that poor sustained attention in deaf children improved little with increasing years [21,22].
The study has several limitations. Firstly, our method of obtaining participants through invitation send to the members of deaf associations resulted in a very small sample size. Secondly, the pre-test was designed for schoolchildren and not for deaf individuals. Due to reading comprehension and health literacy issues a speci c pre-test should be developed for deaf adults. Thirdly, we used different measuring instruments before and after the course which made comparison of the results before and after an intervention inconvenient. Finally, we have not tested the retention of BLS and AED skills.

Conclusions
This study shows that a more comprehensive approach is needed in BLS and AED training for deaf people. Challenges in this speci c population require speci c adjustments of BLS and AED courses, extending beyond modi cations of the BLS algorithm. Further studies are needed to determine an effective approach to BLS and AED training courses for deaf people.

List Of Abbreviations
BLS: Basic life support AED: Automated external de brillator Declarations Ethics approval and consent to participate The study was approved by the National Medical Ethics Committee of the Republic of Slovenia (No. 0120-541/2017/6). Before the beginning of the course the participants received a letter describing the purpose and content of the study, informed consent form and data administration consent form, consistent with Global data protection regulation (EU) 2016/679. If needed, the participants were able to obtain a further explanation of the study by the research coordinator. All the information was translated to sign language by a certi ed sign interpreter.

Consent for publication
Not applicable.