Compression-Only Versus Standard Basic Life Support Training in Nursing Students

Design and setting: randomized experimental study with two parallel groups, conducted at the Centro Integral de Simulación Avanzada (CISA) of the Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès (Barcelona, Spain), following CONSORT recommendations.

Population and allocation: first-year nursing degree students at UIC. After an information session and written informed consent, participants will be randomly allocated into two groups of equal size: the control group (CG) or the intervention group (IG). Staff responsible for recruitment will not have access to the randomization sequence. To maintain participant blinding, participants will be informed beforehand that they will receive different training modalities and that they must apply the content learned in the initial and 4-month follow-up assessments.

Sample size: calculated with G*Power (effect size d = 0.59, derived from a previous study in the same population and institution; alpha = 0.05; two-sided test; power 80%): 47 participants per group; allowing for 10% losses, 52 participants per group (104 in total) will be enrolled.

Interventions: both groups will receive BLS and AED training delivered by official European Resuscitation Council (ERC) instructors. Instructors will be assigned to one of the two training models (with or without rescue breaths). CG: BLS and AED training with traditional CPR (30 chest compressions and 2 mouth-to-mouth rescue breaths). IG: BLS and AED training with continuous chest compressions without mouth-to-mouth rescue breaths.

Procedures: before training, participants will complete a sociodemographic questionnaire, a physical activity questionnaire (IPAQ-SF) and a questionnaire on self-perceived BLS and AED knowledge. After training, participants will complete the final theoretical test (10 multiple-choice questions from the Catalan Resuscitation Council) and an individual practical assessment: an identical clinical case for both groups with 8 minutes of uninterrupted CPR on a Resusci Anne QCPR manikin (Laerdal) connected to SkillReporter software. CPR quality data will be recorded continuously and every 2 minutes (2, 4, 6 and 8 minutes). Practical performance will be rated by the instructor using the CORVAL rubric. Before and immediately after the simulation, perceived exertion (modified Borg scale), muscular fatigue (dynamometer: sustained 20-second contraction of a hand-held pneumatic bulb, with software recording the force curve), blood pressure and heart rate (blood pressure monitor) and peripheral oxygen saturation (non-invasive finger pulse oximeter, outside the CPR period) will be measured; heart rate will also be recorded continuously during the simulation with an arm heart rate monitor. Self-perceived knowledge will be assessed again after the simulation, and participants will complete a satisfaction survey. Manikins of the same model will be used; their use will be documented and they will be randomly assigned. Before the intervention, a pilot test with the same characteristics will be carried out to ensure feasibility, correct application of the measurement instruments and standardisation of the simulation conditions.

Retention: 4 months after training, before the retention assessment, participants will complete a second sociodemographic questionnaire, including CPR training received during the study. The theoretical and practical assessment will then be repeated following the same procedure, without fatigue measurements. After the assessment, the self-perceived knowledge questionnaire will be administered again.

Statistical analysis: quantitative variables will be described as mean and standard deviation or median and interquartile range, according to normality (Kolmogorov-Smirnov test). Between-group comparisons will use Student's t test or Mann-Whitney U test, and chi-square (with Yates correction) or Fisher's exact test for categorical variables. Multivariable logistic regression (enter method) will be used to identify factors associated with competence, retention and rescuer fatigue, including type of training and sociodemographic variables. Pearson or Spearman correlation will be used according to normality. Retention at 4 months will be analysed with the same tests and, when appropriate, with paired t test or Wilcoxon test. A p value < 0.05 will be considered statistically significant, and 95% confidence intervals will be calculated for measures of association (odds ratios or mean differences). Analyses will be performed with IBM SPSS Statistics.

At the end of the study, participants who did not learn the BLS and AED algorithm with rescue breaths will be trained in it, so that no participant's training is compromised with respect to current standards.