Evaluation of the Effectiveness of Basic Life Support Training on the Knowledge and Skills

Sudden Cardiac Arrest (SCA) is one of the most common causes of death in many countries (1). While for many of the victims a Cardio Pulmonary Resuscitation (CPR) was performed, the survival to discharge after CPR was about 6.9% (2).

This study was an analytic interventional study conducted among the medical students in their sixth academic year during their eight-week emergency medicine training course in Tehran University of Medical Sciences. All students were asked to complete an informed consent form. The teaching committee of the emergency department (consisting of faculties of emergency department) approved the study. In addition, the ethical approval was obtained from the ethics committee of Tehran University of Medical Sciences.

In the beginning, a standard Objective Structured Clinical Examination (OSCE) was obtained from the students at the Clinical Skills Center of Tehran University of Medical Sciences. During the exam, students were supposed to perform different parts of BLS on a standard manikin, and a rater evaluated their skill using the 2006 American Heart Association (AHA) CPR testing checklist including checking for unresponsiveness by shouting and shaking the manikin, asking for help and calling EMS, opening the airway using head tilt-chin lift maneuver, checking breathing, giving two breaths, checking the carotid pulse, baring the victim's chest and locating the CPR hand position, performing the first cycle of compressions, and giving two breaths after the first cycle of compressions. The students were rated for the first nine skill steps and also an additional step regarding checking for environmental safety. Skills related to Automated External Defibrillator (AED) were omitted from the test. For each step, the student got one score for appropriate performance and zero for inappropriate one. A total score of ten was for complete performance in all steps. A single rater (an emergency medicine resident) evaluated all the tests and all the students.

After the exam, all the participants attended a BLS training workshop in which major BLS techniques were taught by the faculties of emergency medicine.

The workshop was a six-hour course divided into two sessions, and every session was divided into one hour of theoretical training and two hours of practice on the standard manikin. Each student should have participated in at least five real CPRs during his/her emergency rotation. At the end of the eight-week rotation, students were re-assessed for BLS skills by the same standard OSCE. The collected data was analyzed using SPSS (Statistical Package for the Social Sciences) version 17 for Windows (Chicago, IL, USA).

The data was analyzed anonymously and expressed as means ± S.D and percentage. Wilcoxon signed rank test, Mantel-Haenszel test, McNemar's test and paired T-test were also used for statistical analysis, and
P-values

Results

Ninety medical students, 39 men (43.3%) and 51 women (56.7%) volunteered to enter this study.

The mean score of the participants in the first OSCE was 4.9±2.07 with 55 students (61.1%) having a score between zero and five and 35 (35.89%) between five and ten. In the second exam, the mean score was 8.5±1.44 with 19 students (21.1%) having a score between zero to seven and 71 (78.9%) a score between seven and ten.

The mean score in the second OSCE was significantly higher than the primary exam (P=0.000).

Students’ scores in the first and the second OSCE shown in Table 1. There were no significant differences in the examination scores between genders, neither in primary nor in the secondary exam (P=0.12).

Checking for environmental safety: Before the training workshop, 28 students (31.1%) checked for the safety of the environment before reaching to the manikin. By the end of the course, a statistically significant difference was shown with 71 students (78.8%) doing the safety check (P= 0.000).

Checking for unresponsiveness: Before the workshop, 42 students (46%) shook the manikin and 46 (51.1%) shouted to check for its responsiveness. After the training, these numbers rose to 88 for shaking (97.8%) and 87 (96.7%) for shouting (P=0.000). Asking for help and calling EMS: Before the training, 27 students (30%) asked for help and called EMS, while 88 (97.7%) did these steps after the workshop (P=0.000).

Opening airway using head tilt-chin lift: In the first OSCE, 27 students (30%) did an accurate head tilt-chin lift maneuver, but in the second exam, 73 students (81.1%) had a correct performance (P=0.000).

Checking breathing: Thirty-one students (34.4%) checked for breathing in the first exam and 74 of them (82.2%) performed it in the second one (P=0.000).

Giving two breaths: In this part, 44 students (48.8%) before the training course and 84 students (93.3%) after it had an accurate performance (P=0.000).

Checking carotid pulse: Nineteen students (21.1%) checked for carotid pulse before the training while 65 students (72.2%) did this part after the workshop (P=0.000).

Baring the victim's chest and locating the CPR hand position: Seventy-nine students (87.8%) before the training and 86 students (95.5%) after it chose a correct location for chest compression and had an acceptable hand position. There was not statistical significance regarding baring the victim's chest and locating the CPR hand position between pre-test and post-test score (P< 0.11).

Performing the first cycle of compressions: In this section the numbers of compressions along with the appropriate depth were evaluated. During the first OSCE, 51 students (56.7%) performed 30 compressions in less than 23 seconds. In the second exam, 80 of them (88.9%) did adequate number of compressions (P=0.000).

Giving two breaths after the first cycle of compressions: Before the workshop 17 students (18.9%) performed this step properly, while 41 (45.6%) gave two appropriate breaths to the manikin in the second exam (P=0.000).

Discussion

The current study compared the knowledge and skills of BLS among medical students at the beginning and the end of the training course in an emergency department. We found that BLS training course could significantly increase the knowledge of medical students who should have the ability to recognize several life-threatening emergencies and provide CPR in a safe, timely, and effective manner. The influence of adequate knowledge on the accuracy and quality of BLS/CPR has been shown in studies (10). In addition, early institution of CPR can remarkably increase the victim’s chance of survival from sudden cardiac arrest (11, 12). In our study, pattern of responses showed that medical students had unstructured knowledge of BLS.

Similarly, a study that was conducted in Pakistan showed scattered knowledge about BLS among medical students (13, 14). Moreover, a larger study in South India concluded that awareness of BLS among students, doctors, and nurses of medical, dental, homeopathy, and nursing colleges was very poor (14).

Our results are in accordance with poor performance of healthcare providers in manikins described by Flesche (15). Previous studies showed that CPR plus early delivery of shock can provide survival rates as high as 49 to 75% (16, 17). While missing or delaying the diagnosis of cardio circulatory arrest will reduce the patients’ chance of survival to zero within about 10 minutes (3). Therefore, with a simple course we could improve skills of BLS in medical students. In a study conducted by Flesche et al, it was shown that in CPR manikins only 50% of BLS-trained medical students, 17% of experienced ambulance crew members, and 3% of BLS-trained lay persons were able to assess unresponsiveness and carotid pulse within 30 seconds (15, 18). Thus, knowledge about carotid pulse checking has been described as modest. Similarly, our study demonstrated that medical students have some problems in BLS skills such as checking for carotid pulse and checking for unresponsiveness or maintaining accurate CPR sequence in giving two breaths after the chest compressions cycle. These steps, though seemingly simple, have many important effects on the CPR outcome. Hence, BLS training may improve these pivotal skills in medical students. In addition, the findings of our study showed a significant improvement in CPR skills except hand position and chest compression depth. The less improvement in correct hand position and depth of compression may be due to previous knowledge of the students in this study.

Taking everything into consideration, structured teaching of BLS/ACLS is lacking in medical curriculums because medical students are currently expected to learn resuscitation skills in a clinical setting, where there is little opportunity to correct poor techniques (8, 9). On the other hand, after graduation, learning resuscitation skills may be complicated due to busy residency schedules and lack of resources. Given this situation, many junior doctors may not be competent enough to carry out effective cardiopulmonary resuscitation without a structured training course. In conclusion, CPR workshops and usage of manikin for CPR training can improve medical students’ skills and should be considered as an obligatory part of training in medical courses.