Yup, that’s right, we are going to go through the RUSH exam this week. Its “RUSH” WEEK!!!! To all those in SonoSororities and SonoFraternities out there, this week is going to be dedicated to “rush”ing to evaluate the patients in shock, and trying to figure out the cause of it by your handy-dandy bedside US machine – especially when the case is not obvious, but you know you need to “rush” to their bedside….ok, Ill stop “rush”ing :)
RUSH stands for Rapid US in SHock and written by great friends of mine, namely Phil Perera, Tom Mailhot, D Riley, and Diku Mandavia who coined the terms Pump-Tank-Pipies – with inspiration from an original RUSH protocol by another great friend of mine, Scott Weingart (aka emcrit) who coined the acronym HIMAP (heart, IVC, Morison’s (and other FAST views), Aorta, Pneumothroax (see a great podcast by him here). Both start with the heart, and for good reason – you may find the cause immediately, and you’ll be able to identify if the patient can tolerate fluids. Both also arose from varying research studies by Rose et al. (the UHP protocol) and by Bahner et al (Trinity protocol). Here, we will discuss the 3 sections to evaluate:
The PUMP: aka the heart, do a bedside echo (look for RV or LV hypokineses, hyperdynamic, tamponade)
check its volume (look at the IVC)
see if it is leaking (look for fluid – FAST for ascites/pleural effusion, Thoracic for B lines)
see if it’s compromising the pump (look for pneumothorax)
The PIPES: aka the Aorta and deep veins – for dissection, AAA, DVT
By going through the RUSH exam in a stepwise fashion, you will be able to identify any emergent conditions which is causing shock, and the type of shock it is:
So, lets start with our first case: this is a true case I had a couple years back….78 year old overweight male, history of hypertension, diabetes mellitus, peripheral vascular disease, CHF, diverticulitis who was brought in because he got up from the bathroom toilet and had a syncopal episode after having taken his morning anti-HTN medications and starting a new antibiotic for a recently diagnosed UTI. He has come to, but is seemingly not acting himself, disoriented. He comes in appearing pale, diaphoretic, is not in respiratory distress but breathing slightly more rapid, and winces when you touch his abdomen (but seems to wince when you press on his chest or when you move his arms or legs too). His lungs are coarse bilaterally, his heart is tachycardic and he has bilateral peripheral edema to his ankles with palpable but weak DP pulses. His vitals: 37.4 120 22 80/52 99%RA. I know what you’re thinking – is this cardiogenic shock since he does have significant disease? Is this septic shock since we know that the elderly may not mount a febrile response? Is this CHF exacerbation, but he isn’t in significant respiratory distress? Is this anaphylactic shock since he started this new antibiotic? My clinical exam didnt help me much, and I didnt have records on him yet (nor did I have time to look). Well, after we order his oxygen by non-rebreather, 2 large bore IVs and normal saline bolus, placing him on the cardiac monitor seeing sinus tachycardia, I grab my US machine. Lets go through his RUSH:
The PUMP: Using the subxiphoid view, placing your probe just under the xiphoid process and flattening it down to angle up toward the heart (indicator to the patient’s right side for abdominal presets), ensuring to see the liver which helps you as “acoustic window” to see the heart.
I then look on his anterior chest wall using the low frequency probe, at the 4th-5th rib space just left of the sternum, indicator pointed to the left hip (again, for the abdominal presets – noncardiologist way) to look at the kinetics of the LV and the ascending aortic root and descending aorta seen posterior to the heart in transverse view…
Ok, so he is tachycardic, but definitely no tamponade or right ventricle strain/dilation, or significant hypokinesis….so, no acute MI, no tamponde, no significant pulmonary embolus causing his shock…. its actually pumping better than I thought it would be given his past medical history…. lets keep going…
IVC: from the subxiphoid view above, you turn your probe 90 degrees to have it be the sagittal plane of the body, visualizing the IVC enter the right atrium, checking to see if the volume status of the patient is low (<1.5 cm width with >50% collapse), normal (1.5-2.5cm diameter with 50% collapse) or high (>2.5 cm with <50% collapse)
Ok, so the volume is slightly low…. again, a bit different than what I expected, so we know it’s not cardiogenic shock with the above 2 findings already….
FAST: Placing the low frequency probe in the midaxillary line on the right and left side of the patient with the indicator pointed to the patient’s head we look for pleural fluid in the thoracic cavity (absence of mirror imaging of liver on right or spleen on left) and for ascitic fluid in the hepatorenal and splenorenal spaces for leakiness of the tank. Then we place the probe just above the pubic symphosis with the indicator toward the patient’s right side looking for free fluid around the bladder….
Ok, so no free fluid anywhere…..let’s order some more IV fluids and move on…
Thoracic: we place the low frequency probe on the chest wall , 4 sides of each side of chest to look for more than 2 B lines (rays coming down from the pleural line to the end of the screen) in more than 2 quadrants, bilaterally to be able to diagnose pulmonary edema (another sign of a leaky tank)… the absence of those B lines would be a normal finding…. The right and left chest is shown below (only showing you 2 views to not waste your time with other 6….)
I then look for any compromise of the pump by the tank – pneumothorax. I switch probes to the high frequency linear probe and place it on the anterior chest wall, second intercostal space, midclavicular line, indicator toward the head and look for normal sliding lung with comet tail artifact coming from the pleural line just below the rib. This is what I see on both sides of the chest:
ok, so there are a few B lines on the left chest but none on the right, and the rest of the chest being normal as well – there is no signs of true pulmonary edema…. I feel better about my fluid order and since there is no pneumothorax (which was not a surprise to me given his O2 sat and exam) I think, I bet this is septic shock since he has a known UTI, but Ill finish the RUSH anyway….
Aorta: Ive already looked in the parasternal view of the heart and saw that his ascending aortic root and descending aorta (at least, the portion that I can see) is normal diameter. I then place my low frequency probe on his abdomen, perpendicular to his body to obtain a true transverse view of his abdominal aorta, avoiding elongating the aorta on the screen. I start subxiphoid and travel down to the bifurcation:
Ok, we can probably stop right there. Now, if any of you were expecting this finding then you are smarter than me, because I sure was not….. the nurse came right at that time and said his last Echo showed EF of 45% (pretty good!). She stopped there, but I was curious, “Did he have a CT abdomen done recently?” – his last abdominal CT was 7 years earlier with a 2.8cm abdominal aorta – seems like some things keep growing with age. Ordered labs, blood, and called vascular surgery right away – to OR in 10 minutes!
I didnt “rush” the RUSH, got it done within 5 minutes, and had my answer….. “shock”ing, I know….ok, Ill stop :)
For other RUSH cases for RUSH week, go here!
For another great overview of the RUSH protocol in Academic Life in EM, go here.