Impact of loading and transport on effectiveness of external chest compressions : a simulation study

Introduction: Effective external chest compressions (ECC) are recognised as being critical for increasing chances of survival in out-of-hospital cardiac arrest. The aim of this study was to: 1) determine the impact of movement and transport on effectiveness of ECC performed by student paramedics; 2) provide results to inform a future larger study; and 3) validate teaching methods in an undergraduate paramedicine program. Methods: A prospective cohort design was utilised. Student paramedics performed ECC on a manikin under three different conditions: at ground level on a hard floor surface (ground ECC); at waist-height on a moving ambulance stretcher (extrication ECC; and during transport in the rear of a moving ambulance (transport ECC). Three minutes of ECCs was performed under each condition, with periods of rest between phases. The primary outcome was the composite ‘compression score’ (CS) (%). Results: Twenty-seven student paramedics performed chest compressions under all three conditions. For the primary outcome comparison of CS, there were clinically significant differences in ECC quality across the three conditions. Ground ECC produced the highest CS (89%; IQR 46), followed by transport ECC (54%; IQR 40). Extrication ECC was least effective (CS 0%; IQR 14). Conclusion: The conditions under which ECC are performed significantly affects ECC quality. The quality of ECC is substantially reduced if performed in the back of a moving ambulance, and futile if performed on a moving ambulance stretcher. Paramedics should consider these findings when deciding whether or not to move or transport patients before return of spontaneous circulation. Lower than expected CS on hard ground surfaces may indicate a need to review teaching of ECC in this cohort of students.