NephBytes

The final episode of the hyponatremia series. Covers hypervolemic hyponatremia in cirrhosis — including the potassium-first approach — asymptomatic cirrhotic hyponatremia, and severe hyponatremia requiring emergent dialysis and why CVVH with modified replacement fluid is the only safe option. Closes with a rapid-fire review of all 12 clinical pearls from the series.

Every episode so far has been about ADH being on when it shouldn't be. Today we flip that entirely. This episode covers hyponatremia where ADH is suppressed, the urine is maximally dilute, and the kidneys are doing exactly what they're supposed to — but the patient is still hyponatremic. Either the water intake is overwhelming the kidneys' capacity, or there isn't enough solute to...

Same low osmolality. Same concentrated urine. Same high urine sodium. A clinician scanning those results would call it SIADH without hesitating — and then reach for fluid restriction. In salt wasting, that's exactly the wrong move. This episode covers three salt wasting syndromes where the confusion with SIADH causes real harm. First, cerebral salt wasting after subarachnoid hemorrhage — how t...

Your patient has confirmed SIADH. Now what? This episode is all protocol — four clinical scenarios that cover every treatment situation you'll encounter, from the emergency department to the ICU to the outpatient clinic. We start with acute symptomatic hyponatremia: why the answer is a 100–150 mL bolus of 3% saline, not an infusion, and why normal saline can paradoxically worsen things through...

You've checked the osmolality. It's low. The patient looks euvolemic, the urine is concentrated, the urine sodium is high. It looks like SIADH — and you're ready to make the diagnosis. Not so fast. SIADH is a diagnosis of exclusion. In this episode, we build a precise picture of what SIADH actually is — and why calling it a sodium problem instead of a water problem is the first mistake...

When a sodium comes back at 118, the instinct is to treat. But before anyone touches that IV line, there's one question you need to answer first — is this real hyponatremia? In this episode, we build the osmolality-first framework from the ground up. We cover how hospital labs actually measure sodium, why the indirect ion-selective electrode can be fooled, and how the serum osmolality catches...

A 72-year-old woman in the ICU with pneumonia. Creatinine doubling overnight. Urine output dropping. The intern asks: "Should we start dialysis?" In this episode, we walk through the complete approach to acute kidney injury — KDIGO staging, the diagnostic workup (post-renal, pre-renal, intrinsic), the critical role of FENa and urine sediment, volume and medication management, and the evi...

A 58-year-old man in the ICU with sepsis. pH 7.18. Bicarb 9. What's really going on? In this episode, we walk through the systematic approach to acid-base disorders — from the four-step framework you should use every time, to the anion gap pitfalls most clinicians miss. We cover Winter's formula, the delta-delta ratio, albumin correction, metabolic alkalosis (chloride-responsive vs. resist...