**6. Ultrasound-guided pericardiocentesis**

Ultrasonography alone is unable to explicitly determine the type of pericarditis which may be causing fluid accumulation in the pericardial sac. Pericardiocentesis is needed to characterise the fluid present and is often performed at the left fifth intercostal space, 2.5–10 cm dorsal to the olecranon [10]. Samples obtained from cases of TP are often malodourous, purulent, have elevated protein content (>3.5 g/dl) and on cytology show elevated white blood cells (>2500/μl) (mainly neutrophils) and the presence of mostly commensal bacteria [10]. In comparison to TP, idiopathic pericarditis is rare and in these cases pericardiocentesis is often haemorrhagic. Clinical signs may also improve with the pericardiocentesis, unlike with TP [1, 28].

Risks with pericardiocentesis may be reduced when it is performed with ultrasound guidance rather than blind. However, these risks are still plausible and can include pneumothorax, cardiac puncture, pericardial fluid leakage and formation of arrhythmias [13]. Pericardiocentesis has been described as a successful treatment option alongside pericardial lavage, pericardiostomy and rib resection in some cases of TP but evidence still remains variable [19]. Studies have shown that performing pericardiocentesis can prolong life when an animal has TP and is pregnant, so that it may deliver [30]. *Evaluation of Current and Future Diagnostic and Prognostic Techniques for Traumatic… DOI: http://dx.doi.org/10.5772/intechopen.106576*
