Since it’s RUSH week and we have presented a case yesterday of how the RUSH exam helped show the etiology of unexplained shock in critical situations, I thought Id look through the research before during and after the RUSH exam was described to see where its base was, how it was proven, and what the future of RUSH may hold…
The FAST scan was the first widely accepted bedside ultrasound application to be implemented into practice amongst emergency physicians and surgeons to evaluate the abdominal blunt and penetrating trauma patient – becoming truly clinically significant in the blunt trauma patient who had a positive FAST scan. This of course was while cardiac and IVC applications were already well known to cardiologists, critical care specialists, and emergency physicians alike. In the mid to late 1990s, bedside ultrasound was becoming more resolute and widely used amongst emergency physicians and critical care specialists, particularly Lichtenstein who was publishing like crazy about lung ultrasound: lung sliding, the comet tail sign, lung point description, and pneumothorax evaluation (later to describe the BLUE protocol for respiratory distress in 2008). During that same time, the two-point compression technique for DVT evaluation was described using bedside ultrasound and an early goal directed approach to sepsis and septic shock was being described.
The hypotensive trauma patient was to get a FAST scan, period. But what about the hypotensive medical patient? Would there be a defined protocol? No big surprise that it would soon be answered: in 2001, Rose JS et al published an article that I believe started the whole thing…describing a novel sonographic protocol for evaluating the medical patient with hypotension. – it involved 3 sonographic views: the heart, the FAST, and the Aorta. This was great, all could use the same low frequency probe, took only a couple minutes and you could rule in emergent conditions quickly. Soon after, more studies came out validating the findings of previous research and illustrating a goal directed approach to the hypotensive medical patient (Jones et al). Other studies evaluated the need for bedside ultrasound in cardiac arrest.
The Rapid Ultrasound for Shock and Hypotension exam (RUSH), described by both Dr. Scott Weingart (with a great acronym HIMAP) and in 2007 by Perera et al (Pump-Tank-Pipes), is an easy way to evaluate the patient with unexplained shock: an easy to remember name (RUSH) with an acronym (HI-MAP) that serves to help guide the sonographer with knowing the required views: Heart, IVC, Morrison’s [for FAST], Aorta, Pneumothorax. It allows us to evaluate the pump, the tank, the pipes. This not only allows us to diagnose the etiology of shock, but it helps us guide its management. The Italians have also done a study stating that a multi-organ approach in the undifferentiated hypotensive patient can help identify the etiology.
Since the RUSH was explained, studies have shown physician’s certainty in diagnosis improved, their accuracy has increased, and their patients have quicker management. Lichtenstein is integrating lung ultrasound into acute circulatory failure too! The future of bedside ultrasound in shock is will advance to other areas, possibly add additional applications, and definitely be refined in its approach.
Just as the FAST scan should not be done fast, the RUSH exam should not be rushed. Be deliberate, and take the time, and for no other reason (like saving lives) it will make you look really smart. For RUSH SonoCases, go here.