Reliability of focused cardiac ultrasound by novice sonographer in preoperative anaesthetic assessment: an observational study.

BACKGROUND: Use of preoperative echocardiography may help to identify patients with increased cardiac risk, who may benefit from modification of perioperative plan. The objective of our study was to evaluate the reliability of preoperative focused cardiac ultrasound (FoCUS) performed by an anaesthetist with basic ultrasound training and its impact on patient's management.

METHODS: The prospective observational study was conducted in 159 adult patients, scheduled for elective operations. Cardiac ultrasound was performed by one anaesthetist with a limited experience of FoCUS. A simple, mnemonic scheme was used for the final reporting of each study. The same scheme was used by a cardiologist who produced an independent report based on digital video loops stored in the machine memory. Anaesthetists in-charge made final perioperative plan. Comparative analysis of anaesthetist and cardiologist performed ultrasound report was made. The incidence of modification of initial perioperative plan resulting from FoCUS report was analyzed.

RESULTS: The average time required to complete the examination was 182 s 95% CI [173-190]. Images of quality adequate to answer all questions from the scheme were obtained in 97.5% (155/159) of patients. There was strong agreement between the anaesthetist and the cardiologist in 97.8% (2274/2325) of the examined categories. In two categories (global and regional left ventricle contractility impairment) statistically significant discrepancies between both diagnosticians were confirmed (p McNemar <0.04). When compared with the cardiologist's assessment the agreement of the anesthetist's diagnosis had sensitivity of 0.84, specificity 0.99, positive predictive value 0.78 and negative predictive value 0.99. Kappa statistics showed good agreement between both examining doctors (κ = 0.797). Based on ultrasound findings, the preliminary anaesthetic plan was changed in relation to 20.8% (33/159) of patients.

CONCLUSIONS: An anaesthetist with limited training in FoCUS can perform a reliable preoperative examination which alters the perioperative management.