Focused cardiac ultrasound in preoperative assessment: the perioperative provider's new stethoscope?

Focused cardiac ultrasound (FoCUS)-a simplified, qualitative version of echocardiography-is a well-established tool in the armamentarium of critical care and emergency medicine. This review explores the extent to which FoCUS could also be used to enhance the preoperative physical examination to better utilise resources and identify those who would benefit most from detailed echocardiography prior to surgery. Among the range of pathologies that FoCUS can screen for, the conditions it provides the most utility in the preoperative setting are left ventricular systolic dysfunction (LVSD) and, in certain circumstances, significant aortic stenosis (AS). Thus, FoCUS could help answer two common preoperative diagnostic questions. First, in a patient with high cardiovascular risk who subjectively reports a good functional status, is there evidence of LVSD? Second, does an asymptomatic patient with a systolic murmur have significant aortic stenosis? Importantly, many cardiac pathologies of relevance to perioperative care fall outside the scope of FoCUS, including regional wall motion abnormalities, diastolic dysfunction, left ventricular outflow obstruction, and pulmonary hypertension. Current evidence suggests that after structured training in FoCUS and performance of 20-30 supervised examinations, clinicians can achieve competence in basic cardiac ultrasound image acquisition. However, it is not known precisely how many training exams are necessary to achieve competence in FoCUS image interpretation. Given the short history of FoCUS use in preoperative evaluation, further research is needed to determine what additional questions FoCUS is suited to answer in the pre-operative setting.