Details modified, generalized, and otherwise fudged to be HIPAA-compliant.
72F with chest pain, abdominal pain, and constipation.
2-3mo weight loss, night sweats.
2-3wk +perineal ?cyst, initially ttp and hurt to walk, but now nontender.
~1wk constipation, BRB on TP.
+crampy LLQ pain 8/10, x3-4 days, improves with positioning (supine with head raised somewhat, 3-4 pillows).
+LUQ and left-sided chest pain x1-2 days, radiates to L arm, not related to exertion, lasts a few minutes.
Diagnosis is… MDS/MPN/MF NOS.
I.e., who knows.
Started on hydroxyurea and decitabine, c/b recurrent bacteremia, so currently tx on hold.
The big idea, and a few finer points.
(Most of the following derived from Chapter 4 of the American Society of Nephrology online Onco-Nephrology curriculum, which is good and great.)
Definition: Chemotherapy plus the two or more of the following within 3d before or 7d after initiation (so doesn't account for the spontaneous TLS seen in our patient).
|Uric Acid||>=8 mg/dL or 25% increase from baseline|
|Potassium||>=6mEq/L or 25% increase from baseline|
|Phosphorus||>=4.5mg/dL or 25% increase from baseline|
|Calcium||25% decrease from baseline|
The “25% increase/decrease” part is contested, as it may not be clinically meaningful if the value stays within the normal range.
|Laboratory TLS and one or more of|
|creatinine >= 1.5 ULN (Note: just use AKI criteria)|
|cardiac arrhythmia or sudden death|
IVF, electrolytes, rasburicase.
Rasburicase is the subject of a recent “Things We Do for No Reason.“
Pay-walled article, PDF made available by the authors
TL;DR: the evidence is thin, but could be reasonable to - ppx w IVF and allopurinol for low-med risk, - use single 3mg dose rasburicase as ppx in high-risk disease (don't use weight-based dosing), - tx active TLS (laboratory or clinical) with aggressive fluid resuscitation and electrolyte mgmt, possibly single 3mg dose.
Hard outcomes in support of rasburicase are generally lacking, e.g. consistently reducing renal injury, renal failure, length of stay.
It also seems like the classification criteria need revamping, with a larger N. It's been a while. However, like redefining fever, it's difficult to get a clean slate, because we act on the established criteria so aggressively.
Not much to say here, except that the dx is not always clear-cut, even with BMBx and NGS data, so the clinical picture matters, and sometimes we have to shoot in the dark.
Last updated: 2021-08-22