Association of Chest Compression Depth, Rate, and Spring Resistance with “Quality CardioPulmonary Resuscitation” (QCPR) Scores in a Manikin Model

Training in high-quality chest compressions (CCs) is essential for effective resuscitation; however, it remains unclear how accurately real-time feedback systems, such as Laerdal Medical's (Stavanger, Norway) Quality CardioPulmonary Resuscitation (QCPR) scoring system, reflect guideline-compliant CC quality. We aimed to investigate how CC depth, rate, and spring resistance affect QCPR scores. We conducted an experimental study using a Resusci Anne QCPR manikin (Laerdal Medical, Stavanger, Norway) equipped with interchangeable 30-, 50-, and 60-kg chest springs and a Corpuls mechanical CC device (GS Elektromedizinische Geräte G. Stemple GmbH, Kaufering, Germany). For each spring resistance, continuous CCs were delivered in two-minute intervals at predefined combinations of CC depth (2.0-6.0 cm) and rate (80-120 compressions per minute). CC quality was quantified using the QCPR score (0%-100%). Across all spring resistances, QCPR scores rose modestly at 3.0-3.5 cm and increased further at 4.0-4.5 cm, where the greatest score variation across preset CC rates and spring resistances was observed. At ≥ 5.0 cm, QCPR scores were consistently high (57%-100%). Overall, CC depth was the primary determinant of the QCPR score, with the highest scores observed at ≥ 5.0 cm. Additionally, we observed QCPR score differences of up to 18% for identical preset CC depth and rate settings with different springs. High QCPR scores were often achieved outside guideline ranges, emphasizing the need to interpret QCPR scores alongside absolute CC parameters and use guideline-compliant metrics as the standard for training and research.