Video analysis of dispatcher-rescuer teamwork—Effects on CPR technique and quality

Abstract

1 CC only (n = 85) 46 0.87 (0.54-1.38) 0.54 0.78 (0.48-1.27) 0.32 Full-CPR (n = 71) 62 1.66 (1.00-2.78) 0.05 1.32 (0.77-2.27) 0.31 1.2 1.09 (0.85-1.39) 0.51 1.02 (0.80-1.31) 0.85 Full-CPR 2.8 1.50 (1.13-1.99) 0.005 1.34 (1.00-1.78) 0.048 Purpose of the study: Intrathoracic pressure variation (ITPV) during resuscitation (the thoracic pump) results from pressure generated by chest compression and ventilation. We studied the relation between chest compression depth, ventilation pressure and ITPV. Materials and methods: The study was approved by the Ethics Committee of Ghent University Hospital. In 51 patients undergoing out-of-hospital resuscitation by a physician-staffed team, compression depth (CD) during manual chest compression was measured using an accelerometer (Zoll, US). After intubation, airway pressure (a surrogate for intrathoracic pressure) was measured. Accelerometer and airway pressure data were synchronised offline using custom Visual Basic code in Excel. For every chest compression, ITPV (the difference between the compression-induced peak and nadir pressure) was sep- arated from the concomitant ventilation pressure (Pvent). The relationship between ITPV and CD was analysed with linear regression for a CD range of 2.5-6 cm. Pvent ranges of 0-10 and 10-30 cm H2O were analysed separately because of a breakpoint in the regres- sion line. In order to weigh each patient equally, the median ITPV value at each Pvent or CD within each patient was used for regression analysis. Results: A total of 39,278 datasets were analysed. For Pvent 0-10 cm H2O, the rela- tionship with ITPV was described as ITPV = 2*Pvent + 6 (R2 = 0.96), for Pvent 10-30 cm H2O as ITPV = 0.6*Pvent + 29 (R2 = 0.94). For CD 2.5-6 cm, the relationship with ITPV was described as ITPV = 0.3*CD + 19 (R2 = 0.82). Therefore, an increase of Pvent from 0 to 10 cm H2O increased ITPV with 20 cm H2O, while an increase of CD by 2 cm increased ITPV by only 0.6 cm H2O. Conclusions: The effect of chest compression depth on ITPV is small, but can be increased very significantly by Pvent. Further studies are needed to investigate the relation