Training to deeper compression depth reduces shallow compressions after six months in a manikin model

IntroductionStudies show that students, trained to perform compressions between 40 and 50 mm deep, often do not achieve sufficient depth at retention testing. We hypothesized that training to achieve depths >50 mm would decrease the proportion of students with depth <40 mm after 6 months, compared to students trained to a depth interval of 40–50 mm.MethodsA basic life support (BLS) self-learning station was attended by 190 third year medicine students. They were first offered the possibility to refresh their skills, following the instructions of a 15 min abbreviated Mini Anne™ video (Laerdal, Norway) using a full size torso and a face shield. This was followed by further training using Resusci Anne Skills Station™ software (Laerdal, Norway). Voice feedback was provided according to randomisation to a standard group (SG) 40–50 mm and a deeper group (DG) >50 mm. Quality of compressions was tested after 6 months.ResultsThe SG and DG groups consisted of 90 (67% female) and 100 (58% female) participants respectively. At the end of training, all students reached the target depth without overlap between groups. After 6 months, the proportion of students achieving a depth <40 mm was 26/89 (29%) in the SG vs. 12/89 (14%) in the DG (P = 0.01). The proportion of students with a depth >50 mm was 5/89 (6%) for the SG and 44/89 (49%) in the DG (P < 0.001).ConclusionsThe educational strategy to train students to a deeper depth, reduced shallow compressions 6 months after training.