Purpose of the Study: Serious thoracic injuries (STIs) are common during cardiopulmonary resuscitation (CPR) (1). The aim of this study was to establish the effect of STIs on haemodynamics during CPR using a theoretical approach based on the Campbell diagram (CD).
Material and methods: A CD is a theoretical framework of the respiratory system that integrates pressure-volume curve of the lung [Pel(L)] and pressure-volume curve of the chest wall [Pel(cw)]. The point where the curves cross corresponds to the functional residual volume (FRV). It permits to represent the thorax in the decompression phase when there is no ventilation during CPR. The authors reviewed the literature that provides information on the construction of the CD and the assessment of the haemodynamic effect of STIs during CPR.
Results: Multiple rib fractures on one side (2) and intrathoracic visceral injuries on the other side (3) has been associated with a decrease on respiratory system compliance.  When representing the fall in compliance in both pressure-volume curve of the CD, a new balance point is established with a new, lower FRV and a higher pleural pressure (fig). An increase in pleural pressure in the chest decompression phase contributes to reduce the gradient between the mean systemic filling pressure and the right atrium pressure impairing the venous return flow. Multiple rib fractures were associated with a worse thoracic recoil and significantly less coronary perfusion (4). 
Conclusions: The Campbell diagram is a useful tool to represent the thorax biomechanics with STIs and its adverse hemodynamic effects during CPR.

1 - Adverse haemodynamic effects of serious thoracic injuries during CPR: a study based on the Campbell diagram.