Social media site @CanadiEM recently featured the @CJEMonline @IFEM2 #SHoC Consensus Protocol, featuring authors from @SJRHEM among others.
So why do we need another ultrasound protocol in emergency medicine? RUSHing from the original FAST scan, playing the ACES, FOCUSing on the CAUSE and meeting our FATE, it may seem SHoCking that many of these scanning protocols are not based on disease incidence or data on their impact, but rather on expert opinion. The Sonography in Hypotension (SHoC) protocols were developed by an international group of critical care and emergency physicians, using a Delphi consensus process, based upon the actual incidence of sonographic pathology detected in previously published international prospective studies [Milne; Gaspari]. The protocols are formulated to help the clinician utilize ultrasound to confirm or exclude common causes, and guides them to consider core, supplementary and additional views, depending upon the likely cause specific to the case.
Why would I take the time to scan the aorta of a 22 year old female with hypotension, when looking for pelvic free fluid might be more appropriate? Why would I not look for lung sliding, or B lines in a breathless shocked patient? Consideration of the shock category by addressing the “4 Fs” (fluid, form, function, and filling) will provide a sense of the best initial therapy and should help guide other investigations. Differentiating cardiogenic shock (a poorly contracting, enlarged heart, widespread lung B lines, and an engorged IVC) in an elderly hypotensive breathless patient, from sepsis (a vigorously contracting, normally sized or small heart, focal or no B lines, and an empty IVC) will change the initial resuscitation plan dramatically. Differentiating cardiac tamponade from tension pneumothorax in apparent obstructive shock or cardiac arrest will lead to dramatically differing interventions.
SHoC guides the clinician towards the more likely positive findings found in hypotensive patients and during cardiac arrest, while providing flexibility to tailor other windows to the questions the clinician needs to answer. One side does not fit all. That is hardly SHoCing news. Prospective validation of ultrasound protocols is necessary, and I look forward to future analysis of the effectiveness of these protocols.
References
Scalea TM, Rodriguez A, Chiu WC, et al. Focused Assessment with Sonography for Trauma (FAST): results from an inter- national consensus conference. J Trauma 1999;46:466-72.
Labovitz AJ, Noble VE, Bierig M, Goldstein SA, Jones R, Kort S, Porter TR, Spencer KT, Tayal VS, Wei K. Focused cardiac ultrasound in the emergent setting: a consensus statement of the American Society of Echocardiography and American College of Emergency Physicians. Journal of the American Society of Echocardiography. 2010 Dec 31;23(12):1225-30.
Hernandez C, Shuler K, Hannan H, Sonyika C, Likourezos A, Marshall J. C.A.U.S.E.: cardiac arrest ultra-sound exam – a better approach to managing patients in primary non-arrhythmogenic cardiac arrest. Resuscitation 2008;76:198–206
Atkinson PR, McAuley DJ, Kendall RJ, et al. Abdominal and Cardiac Evaluation with Sonography in Shock (ACES): an approach by emergency physicians for the use of ultrasound in patients with undifferentiated hypotension. Emerg Med J 2009;26:87–91
Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in Shock in the evaluation of the critically lll. Emerg Med Clin North Am 2010;28:29 – 56
Jensen MB, Sloth E, Larsen KM, Schmidt MB: Transthoracic echocardiography for cardiopulmonary monitoring in intensive care. Eur J Anaesthesiol. 2004, 21: 700-707.
Gaspari R, Weekes A, Adhikari S, Noble VE, Nomura JT, Theodoro D, Woo M, Atkinson P, Blehar D, Brown SM, Caffery T. Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest. Resuscitation. 2016 Dec 31;109:33-9.
Milne J, Atkinson P, Lewis D, et al. (April 08, 2016) Sonography in Hypotension and Cardiac Arrest (SHoC): Rates of Abnormal Findings in Undifferentiated Hypotension and During Cardiac Arrest as a Basis for Consensus on a Hierarchical Point of Care Ultrasound Protocol. Cureus 8(4): e564. doi:10.7759/cureus.564
Sonography in Hypotension and Cardiac Arrest: The SHoC Consensus Statement
