This is a case that ended up being a 72 hour return. Another good example that sinus tach should have a good explanation. Another good reason to know discharge vitals!

Middle aged M, history of TBI, PE, MRSA bacteremia, s/p trach/g-tube/IVC filter, presents with displaced g-tube and increased agitation. Trauma consulted, g-tube replaced. Fluro shows good placement. Exam otherwise unremarkable. No labs performed. Documentation of to be non-verbal/not following commands and this was baseline. VS prior to discharge. Normal BP, HR trend: 68->70->115->111 (at discharge)

Patient returns for changed mental status. Not documented in what way he was changed from baseline. But found to have BUN: 115., Cr: 2.96. BP 90’s systolic, HR wnl. Head CT negative. Hgb: 12, INR: 1.6 (on coumadin) Na: 154, Cl: 112. Otherwise labwork unremarkable.

Patient admitted to medicine service. Hgb trended down 12.4->9.8->8.4. Patient receiving IV fluids during this time. Mild improvements in BUN/Cr. Patient was a STAT response 5 days later. Hypotensive/tachy. Hgb: 5.3 Dark stools noted. Transferred to MICU. GI scoped, found to have erosion of IVC filter into duodenum. Vascular consulted. Patient transfused/stabilized. IVC filter removed, transferred to floor. BUN/Cr normalized during stay.

Two things here, the HR as mentioned, should always have a good explanation. In a patient like this, the history is limited, more information is probably useful than less. Granted a patient like this is very difficult to evaluate at baseline, I’d lean towards shotgun labs/imaging etc. Not sure if it would’ve made a difference in the end but nonetheless.

On the 2nd visit though, a BUN of 115 should raise an eyebrow That’s a BUN/Cr ratio greater than 20. This patient could be just a simple AKI due to hypovolumia. But a BUN that high should also raise the suspicion of a GI bleed. A hemoccult probably is indicated at this point (for somebody that can’t relay much information at baseline). I don’t think anybody would’ve predicted the cause, but nonetheless, neither any of us, nor IM really interpreted that BUN as it should’ve. Just a few notes on Bun/Cr below taken from life in the fast lane. Not definitive, but just something to do a double take on.

Urea:Creatinine Ratio (in the setting of renal failure / elevated creatinine)

20:1 – normal or post renal cause of AKI
>20:1 – pre-renal cause (urea absorption increased compared to creatinine)
<20:1 – intrinsic renal damage (urea unable to be absorbed -> become like creatinine -> ratio gets closer to 1)