Perioperative Point-of-Care Ultrasound

Research Unit Description

The Perioperative Point-of-Care Ultrasound clinical research team consists of 3 physician clinician investigators, a research manager and two research assistants plus 1-2 anesthesia fellows every year. The group has a long history of innovation in perioperative interventional and diagnostic applications of ultrasound imaging to advance patient safety.  On the diagnostic side, the group is interested in the full spectrum of point-of care diagnostic applications.    

Research Focus

One of the group's specific contributions in the past few years has been the development and validation of a point-of-care gastric ultrasound protocol for the evaluation of gastric content and aspiration risk. Members of the team have defined the ultrasound scanning technique, described sonographic patterns associated with clear fluid, thick fluid and solid gastric contents and developed a mathematical model based on a 2D-measure of antral area to estimate gastric fluid volume.  In addition, they have proposed a clinical algorithm and described the findings consistent with different levels of aspiration risk.  The research team is currently working on the validation of this point-of-care tool by establishing its diagnostic accuracy (sensitivity, specificity and predictive values) and its reliability.  In collaboration with colleagues from other Canadian and International Centers they are studying this tool in the pediatric, obstetric and severely obese individuals.

The group's knowledge translation and dissemination activities include the creation of a dedicated website (gastricultrasound.org), development of an e-learning module (in collaboration with an international e-learning provider) and hosting CME events focused on perioperative diagnostic ultrasound in cardiac, lung, airway, gastric content.  

Selected Publications

1. Prasad A, Yu E, Wong DT, Karkhanis R, Gullane P, Chan VWS. Comparison of sonography and computed tomography as imaging tools for assessment of airway structures. J Ultrasound Med 2011; 30: 965–972
2. Cubillos J, Tse C, Chan V, Perlas A. Bedside Ultrasound Assessment of Gastric Content.  An observational study.  Canadian Journal of Anesthesia 2012; 59(4) 416-423
3. Perlas A, Mitsakakis N, Liu L, Cino M, Haldipur N, Davis L, Cubillos J, Chan V.  Validation of a mathematical model for ultrasound assessment of gastric volume by gastroscopic examination. Anesthesia and Analgesia 2013 February; 116(2) 357-363
4. Kruisselbrink R, Arzola C, Endersby R, Tse C, Chan V, Perlas A.  Intra and inter-rater reliability of ultrasound assessment of gastric volume.  Anesthesiology 2014 July; 121 (1):46-51
5. Alakkad H, Kruisselbrink R, Chin K J, Niazi A, Abbas S, Chan V, Perlas A.  Point-of-care gastric ultrasound defines gastric content and changes the anesthetic management of elective surgical patients who have not followed fasting instructions.  Canadian Journal of Anesthesia 2015 November; 62(11):1188-1195
6. Perlas A, Van de Putte P, Van Houwe P, Chan VWS.  An I-AIM framework for point-of-care gastric ultrasound.  British Journal of Anesthesia 2016 January; 116:7-11