When to intubate in GCS?

GCS ≤ 8 requires intubation for airway protection. The patient cannot protect their own airway at this level of consciousness. Motor score is the most prognostically important component.

What is the best initial fluid for sepsis resuscitation?

Lactated Ringer's (LR) is the preferred resuscitation fluid. The SMART trial (2018) showed balanced crystalloids reduced death, new renal failure, and persistent renal dysfunction compared to normal saline.

When to start vasopressors in septic shock?

Start norepinephrine (first-line vasopressor) if MAP remains < 65 mmHg after initial 30 mL/kg crystalloid resuscitation, or earlier if patient is profoundly hypotensive. Do not delay pressors to complete full fluid resuscitation.

Why can serum uric acid be normal during acute gout?

During acute inflammation, IL-6 increases renal urate excretion and redistributes urate from plasma to tissues. Up to 40% of acute gout flares have normal serum uric acid. Joint aspiration with polarized microscopy is needed for definitive diagnosis.

How do you distinguish lupus flare from infection in SLE?

Key clues: CRP is low/normal in flare but elevated in infection. Complement (C3/C4) drops in flare but is normal/elevated in infection. Procalcitonin is elevated in bacterial infection but normal in flare. Anti-dsDNA rises in flare, stable in infection.

What is the difference between DKA and HHS?

DKA features acidosis (pH 600), hyperosmolality (> 320), and minimal ketosis -typically in Type 2 DM. DKA requires insulin drip; HHS requires aggressive fluid resuscitation first.

When to give tPA in acute ischemic stroke?

IV alteplase (tPA) can be given within 4.5 hours of last known well time in eligible patients. CT head must rule out hemorrhage first. For large vessel occlusion, mechanical thrombectomy can be performed up to 24 hours with favorable imaging.

What antibiotics for community-acquired pneumonia?

Inpatient non-ICU: ceftriaxone + azithromycin. ICU: ceftriaxone + azithromycin (add vancomycin if MRSA risk). Outpatient healthy: amoxicillin. Outpatient with comorbidities: augmentin + azithromycin or respiratory fluoroquinolone. Duration: 5 days if clinically stable for 48 hours.

How to interpret iron studies?

Iron deficiency: low ferritin (< 30), high TIBC, low iron, low transferrin saturation (< 20%). Anemia of chronic disease: normal/high ferritin (acute phase reactant), low TIBC, low iron. A ferritin of 50-100 in an inflamed patient may still represent iron deficiency.

What is the correction rate for hyponatremia?

Correct sodium no more than 8 mEq/L in 24 hours to avoid osmotic demyelination syndrome (ODS). For symptomatic severe hyponatremia with seizures, give 3% hypertonic saline 100-150 mL bolus over 10-20 minutes. If overcorrected, use D5W + DDAVP rescue protocol.

When to start antibiotics in meningitis?

Within 30-60 minutes. Do NOT delay antibiotics for LP or CT. Draw blood cultures, start empiric antibiotics (vancomycin + ceftriaxone ± ampicillin if > 50 or immunocompromised), then perform LP when possible. Dexamethasone should be given before or with the first antibiotic dose.

DOACs vs warfarin in antiphospholipid syndrome?

DOACs are contraindicated in APS. The TRAPS trial (2018) showed rivaroxaban was inferior to warfarin with more thrombotic events in triple-positive APS patients. Warfarin with INR target 2-3 is the standard for APS, indefinitely.

How to manage scleroderma renal crisis?

ACE inhibitors (captopril) are life-saving -start immediately and titrate aggressively. Do NOT hold for rising creatinine. Steroids > 15 mg prednisone per day precipitate scleroderma renal crisis. ARBs are NOT a substitute -evidence is only for ACEi.

What are the 4 pillars of heart failure treatment?

Guideline-directed medical therapy (GDMT) for HFrEF: (1) ARNI or ACEi/ARB, (2) beta-blocker (carvedilol, metoprolol succinate, or bisoprolol), (3) MRA (spironolactone or eplerenone), (4) SGLT2 inhibitor (dapagliflozin or empagliflozin). All four should be initiated and titrated to target doses.

Calciphylaxis (CUA) -Sodium Thiosulfate Treatment -RoundsRx

🔍 Overview

Definition

Calciphylaxis (preferred current name: calcific uremic arteriolopathy, CUA) is a small-vessel vasculopathy with medial calcification, intimal proliferation, and thrombosis of dermal/subcutaneous arterioles → ischemic skin necrosis with painful violaceous lesions that progress to non-healing ulcers and eschars. Sepsis from infected ulcers is the most common cause of death.

Epidemiology

1–4% of dialysis patients per year (US registry data); higher in obese, diabetic, female ESRD patients.
Female: male ratio ~3:1.
Predominantly in ESRD on dialysis (~80–90% of cases). Non-uremic calciphylaxis exists but is rare (primary HPT, malignancy, autoimmune disease, alcoholic liver disease).
Mean age ~55–60 years.
1-year mortality: ~45–55% overall; ~80% if central (truncal) lesions, ~50% if distal only.

Pathophysiology

Calciphylaxis is not just "high Ca × P precipitating in skin." It is an active, regulated process: vascular smooth muscle cells trans-differentiate into osteoblast-like cells and lay down hydroxyapatite in arteriolar media. Loss of natural calcification inhibitors drives this process.

Matrix Gla protein (MGP) is the body's main vascular calcification inhibitor. It requires vitamin K-dependent γ-carboxylation to be active. Warfarin blocks this (the same mechanism that gives it anticoagulant effect against factors II/VII/IX/X), leaving uncarboxylated, inactive MGP and unleashing arterial calcification. This is why warfarin is a major risk factor.
Fetuin-A, another circulating calcification inhibitor, is depleted in chronic inflammation and uremia.
Hyperphosphatemia directly drives smooth-muscle osteoblast differentiation through the Pit-1 phosphate transporter.
Result: medial calcification → intimal proliferation → microthrombi in dermal/subcutaneous arterioles → ischemic skin and fat necrosis → painful violaceous retiform purpura → ulceration.

Ca × P product, the bedside formula:

Ca × P (mg²/dL²) = Total Ca (mg/dL) × Phosphate (mg/dL)

Target in dialysis patients: < 55 mg²/dL². Above ~55–70, passive precipitation of hydroxyapatite in soft tissue becomes thermodynamically favorable (this approximates the solubility product constant for CaPO₄ under physiologic conditions). Use albumin-corrected Ca, total Ca underestimates ionized Ca in hypoalbuminemia (common in ESRD): corrected Ca = total Ca + 0.8 × (4 − albumin).

Worked example (Case 1 from Rounds tab): Ca 9.8, P 6.4 → Ca × P = 9.8 × 6.4 = 62.7 mg²/dL², above the < 55 target → drives both passive and active calcification.

KDIGO 2017 caveat: the current CKD-MBD guideline moved away from rigid Ca × P targets because (1) single time-point calculations are unreliable (P fluctuates with meals and dialysis), and (2) the dominant biology is active vascular calcification (matrix Gla protein loss, BMP-2 upregulation, smooth-muscle osteoblast trans-differentiation), not just passive precipitation. Use Ca × P as a bedside check but treat Ca, P, and PTH individually. In calciphylaxis specifically, the product is still clinically useful because passive precipitation does matter at scale here.

Risk Factors (Modifiable First, Targets for Treatment)

Risk Factor	Mechanism	Modifiable?
Warfarin use	Blocks vitamin K-dependent activation of matrix Gla protein → unleashes vascular calcification	YES Switch to apixaban
Calcium-based phosphate binders (calcium carbonate, calcium acetate)	Increase calcium load and Ca × P product	YES Switch to non-Ca binder
Hyperphosphatemia (P > 5.5)	Directly drives smooth-muscle osteoblast differentiation via Pit-1	YES Diet, binders, intensified dialysis
Hyperparathyroidism (PTH > 300–500)	Bone resorption → ↑ Ca and P load on vasculature	YES Calcimimetics, parathyroidectomy
High Ca × P product (> 55)	Drives passive precipitation in addition to active calcification	YES Aggressive Ca and P control
Vitamin K deficiency	Same MGP pathway as warfarin (uncarboxylated MGP)	YES Supplement K1 1–10 mg/day
Active vitamin D analogues (calcitriol, paricalcitol) at high dose	Increase intestinal Ca absorption → ↑ Ca load	MAYBE Reduce dose if possible
SC injections (heparin, insulin, enoxaparin) at high-fat sites	Microtrauma triggers calciphylactic lesions at injection sites (a hallmark)	YES Rotate sites or switch route
ESRD on dialysis	Dominant substrate	NO Underlying disease
Female sex, obesity (BMI > 30), diabetes, white race	Demographic risk; mechanisms include adipose-tissue calcification, advanced glycation end-products	NO Non-modifiable
Chronic inflammation, hypoalbuminemia, malnutrition	Depletes fetuin-A; chronic CRP elevation	PARTIAL Address underlying
Hypercoagulable states (protein C/S deficiency, antiphospholipid)	Promotes microthrombosis in already-calcified vessels	PARTIAL Treat underlying

Clinical Presentation

Painful (severe, opioid-requiring, often disproportionate to lesion size, this is the single most useful clinical pearl). Pain often precedes visible skin findings by days.
Violaceous retiform purpura (net-like / livedo-like pattern) → indurated tender plaques → necrotic eschar with surrounding violaceous halo → ulceration with thick black eschar.
Two distribution patterns:
- Central (proximal): trunk, abdomen, thighs, breasts, buttocks. Worse prognosis (1-year mortality ~80%). Often multiple, large lesions.
- Peripheral (distal): calves, feet, fingers, toes. Better prognosis (~50%).
Predilection for adipose tissue: abdomen, thighs, breasts, buttocks. Helpful diagnostic clue.
Lesions at SC injection sites (heparin, insulin) is a near-pathognomonic finding in dialysis patients.
Usually not febrile at presentation unless ulcers are infected; fever is a sepsis red flag, not a primary feature.

Differential Diagnosis

Mimic	Distinguishing Feature
Warfarin-induced skin necrosis	Onset days 3–10 of warfarin, protein C deficiency, breasts/buttocks/extremities, NO ESRD context required. Histology: thrombi without medial calcification.
Cellulitis / necrotizing fasciitis	Fever, leukocytosis, more diffuse erythema, lacks the retiform livedo pattern. Necrotizing fasciitis spreads fast in hours.
Atheroembolic disease (cholesterol emboli)	Recent vascular procedure, livedo + blue toes + eosinophilia + ↓ complement. Usually distal.
Vasculitis (cryoglobulinemia, ANCA, polyarteritis)	Systemic features (fever, arthritis, neuropathy, glomerulonephritis), positive serologies (ANCA, RF, cryocrit).
Pyoderma gangrenosum	Pustule → ulcer with violaceous undermined edge, IBD/RA association, pathergy (lesion at trauma sites).
Nephrogenic systemic fibrosis	Gadolinium exposure in advanced CKD, woody indurated plaques on extremities, NOT painful necrosis.
Oxalate vasculopathy	Primary hyperoxaluria or short bowel; calcium oxalate in tissue (not phosphate). Rare.

🧪 Workup

Diagnosis Is Often Clinical

In a dialysis patient with painful violaceous retiform lesions on adipose-rich areas, calciphylaxis is the diagnosis until proven otherwise. Definitive confirmation requires biopsy, but biopsy itself can extend the lesion and become a non-healing ulcer, so many centers treat empirically when the clinical picture is classic.

Laboratory Workup

Ionized Ca, phosphate, PTH, 25-OH vitamin D, ALP, albumin: characterize the CKD-MBD axis. Look for high P, high Ca, high PTH, high Ca × P product.
BMP, CBC: baseline.
INR, PT, aPTT: especially if patient on warfarin (which is a major modifiable risk factor).
Hypercoagulability workup if young, recurrent, or thrombotic features: protein C and S, antithrombin, factor V Leiden, antiphospholipid antibodies.
Vitamin K status: PIVKA-II (proteins induced by vitamin K absence/antagonist) if available; otherwise empiric supplementation if on warfarin or poor intake.
Wound cultures: if ulcerated, especially if febrile or systemic signs. Sepsis from infected ulcers is the leading cause of death.
Inflammatory markers: CRP, ESR (often elevated, helps trend).
Blood cultures if febrile.

Imaging

Plain X-ray: subcutaneous tram-track / arterial calcifications. Cheap, useful screening.
Bone scan (Tc-99m bisphosphonate): subcutaneous radiotracer uptake at lesion sites. Sensitivity ~90%, useful when biopsy is too risky. Helpful to confirm diagnosis non-invasively.
MRI: assess soft-tissue extent, deeper involvement. Avoid gadolinium in advanced CKD (NSF risk).
CT: shows extent of subcutaneous calcification but adds radiation and contrast risk.

Skin Biopsy (Confirmatory but Risky)

Biopsy is the gold standard but controversial. The biopsy site can become a new non-healing ulcer in this hypercoagulable, ischemic skin. Reserve biopsy for cases where the diagnosis is genuinely unclear (atypical presentation, non-dialysis patient, mimics not excluded). For classic ESRD presentation, many centers skip biopsy and treat empirically.

Histology: medial calcification of small/medium dermal arterioles (von Kossa or Alizarin red stain), intimal proliferation, vascular thrombosis, panniculitis with fat necrosis.
Use punch biopsy from edge of lesion (not center, where necrosis obscures findings).
Avoid biopsying through ulcerated tissue.

🚨 Management

Treatment Is a Coordinated Package, Not a Single Drug

Mortality is 45–80% at 1 year, mostly from sepsis from infected ulcers. No single intervention fixes calciphylaxis. The strategy is to remove all calcification drivers simultaneously, deliver targeted therapy (sodium thiosulfate), and prevent infection. Multidisciplinary team: nephrology, dermatology, wound care, palliative care, surgery as needed.

Step-by-Step Management

Step	Intervention	Why It Matters
1. Sodium thiosulfate (STS)	Sodium thiosulfate 25 g IV over 30–60 min after each HD session (3×/week), continue 3–6 months minimum, often longer until healing	The cornerstone targeted therapy. Chelates calcium → soluble Ca-thiosulfate complex (cleared by dialysis), antioxidant, vasodilator (NO donor). Evidence: large case series (highest-quality available; no RCT). Side effects: metabolic acidosis (anion gap, treat with bicarb), nausea, hypotension, fluid overload. Reduce dose if these are intolerable.
2. Stop warfarin	Switch to apixaban (Eliquis) 2.5–5 mg BID if anticoagulation is still needed	Warfarin inhibits γ-carboxylation of matrix Gla protein, the body's main vascular calcification inhibitor → unleashes calcification. Apixaban does not affect MGP. KDIGO 2017 endorses avoiding warfarin in calciphylaxis. If anticoagulation can be stopped entirely (e.g., AF with low CHA₂DS₂-VASc), do so.
3. Stop calcium-based phosphate binders	Switch to non-calcium binder: sevelamer (Renvela), lanthanum (Fosrenol), ferric citrate (Auryxia), or sucroferric oxyhydroxide (Velphoro)	Calcium carbonate and calcium acetate add to systemic calcium load and Ca × P product. Non-Ca binders lower phosphate without driving calcification.
4. Aggressive phosphate control	Target P < 5.5 mg/dL, Ca × P product < 55. Strict 800–1000 mg/day dietary P. Intensify dialysis (longer sessions, more frequent, low-Ca dialysate 2.0–2.5 mEq/L)	Hyperphosphatemia drives smooth-muscle osteoblast differentiation via Pit-1 transporter. Removing the phosphate driver is essential. Low-Ca dialysate avoids adding calcium during the very treatment that should be removing it.
5. Hyperparathyroidism control	Cinacalcet (Sensipar) 30–180 mg PO daily (titrate to PTH 150–300) or etelcalcetide (Parsabiv) 5–15 mg IV after each HD. Refractory: parathyroidectomy	Calcimimetics activate the parathyroid Ca-sensing receptor → ↓ PTH → ↓ bone Ca and P efflux. Lower Ca, P, and PTH simultaneously, ideal for CUA. Parathyroidectomy reserved for medically refractory severe HPT (PTH > 800–1000 with hypercalcemia).
6. Vitamin K supplementation	Vitamin K1 (phytonadione) 1–10 mg PO daily	Activates matrix Gla protein (the natural calcification inhibitor). Most ESRD patients are functionally K-deficient. Especially important if recently on warfarin. Small RCTs (VitaVasK, others) suggest reduction in vascular calcification. Cheap, low-risk.
7. Wound care, conservative	Sterile non-adherent dressings, gentle cleansing. Avoid aggressive surgical debridement unless infected/septic; lesions can extend and become non-healing	The skin is ischemic; cutting healthy-looking edges propagates the lesion. Debride only frankly necrotic, infected tissue. Wound-care nursing service is invaluable.
8. Pain control	Multimodal: opioids (often required), gabapentin or pregabalin for neuropathic component, ketamine drip in severe cases, regional blocks. Avoid fentanyl patches over lesions	Pain is severe and opioid-requiring. Fentanyl patches absorb erratically over necrotic skin, and the patch's heat further worsens local ischemia. Opioids are dialyzable variably (avoid morphine in ESRD; hydromorphone, fentanyl IV, methadone are options).
9. Infection prevention & treatment	Low threshold for blood cultures and broad-spectrum antibiotics if febrile or systemic signs. Cover MRSA + Gram-negatives (vancomycin + cefepime or piperacillin-tazobactam, dose-adjusted for ESRD)	Sepsis from infected ulcers is the #1 cause of death. Don't wait for classic SIRS criteria; ESRD patients mount blunted febrile responses.
10. Hyperbaric oxygen (HBOT) ADJUNCT	2.0–2.4 ATA × 90 min, 5 days/week × 20–40 sessions	Increases tissue oxygen delivery, promotes angiogenesis, antimicrobial. Case series show benefit; not RCT-proven. Consider for severe or refractory cases at centers with HBOT expertise.
11. Bisphosphonates CASE-SERIES ONLY	Pamidronate 30–90 mg IV every 4–8 weeks	Inhibits osteoclast-mediated Ca/P efflux from bone; possibly direct effect on vascular calcification. Evidence weak (case series). Not first-line; consider in refractory cases or when STS is contraindicated.
12. Palliative care	Early integration, especially for severe/proximal disease	Mortality is high, pain is severe, and quality-of-life conversations are essential. Palliative care is not "giving up", it is good care.

What NOT to Do

Don't continue warfarin if there is any reasonable alternative (apixaban, no anticoagulation).
Don't continue calcium-based binders, switch immediately.
Don't aggressively debride non-infected lesions; the skin is ischemic and debridement extends necrosis.
Don't use IV calcium for hypocalcemia unless symptomatic and severe; binds to phosphate → CaPO₄ precipitation worsens calciphylaxis.
Don't use fentanyl patches over or near lesions.
Don't use gadolinium MRI contrast in advanced CKD/ESRD without weighing NSF risk.
Don't dismiss "bruise-like" pain in a dialysis patient as soft-tissue injury, painful retiform purpura is calciphylaxis until proven otherwise.

💊 Medications

Medications Reference

Drug	Dose	Role	Key Notes & Why It Matters
Sodium thiosulfate CORNERSTONE	25 g IV over 30–60 min after each HD session (3×/week)	Targeted therapy	Chelates Ca, antioxidant, vasodilator. Side effects: anion-gap metabolic acidosis (treat with bicarb), nausea, hypotension, volume overload. Reduce to 12.5 g if poorly tolerated. Continue 3–6+ months until healing.
Apixaban (Eliquis)	2.5–5 mg PO BID	Anticoagulation if needed (replace warfarin)	Does not inhibit matrix Gla protein. Preferred over warfarin in calciphylaxis when anticoagulation is needed. Dose-adjust per ESRD: 2.5 mg BID if 2 of (age ≥ 80, weight ≤ 60 kg, Cr ≥ 1.5).
Sevelamer (Renvela)	800–1600 mg TID with meals	Non-Ca phosphate binder	Polymeric, non-absorbed, no calcium load. Side effects: GI upset, metabolic acidosis. Less effective per-tablet than Ca-based binders (more pill burden).
Lanthanum (Fosrenol)	500–1000 mg TID chewed with meals	Non-Ca phosphate binder	Effective at lower pill burden than sevelamer. Side effects: GI upset. Long-term tissue accumulation (theoretical concern, not clinically validated).
Ferric citrate (Auryxia)	2 tablets (210 mg elemental Fe each) TID with meals	Non-Ca phosphate binder + iron source	Bonus iron repletion useful in CKD-related anemia. Side effects: dark stools, GI upset. Monitor ferritin and TSAT (avoid iron overload).
Sucroferric oxyhydroxide (Velphoro)	500 mg (1 tab) TID chewed with meals	Non-Ca phosphate binder	Lowest pill burden of the iron-based binders. Minimal systemic iron absorption (vs ferric citrate). Side effects: dark stools, diarrhea.
Cinacalcet (Sensipar)	30 mg PO daily, titrate to 30–180 mg/day	Calcimimetic for hyperparathyroidism	Activates parathyroid Ca-sensing receptor → ↓ PTH, ↓ Ca, ↓ P. Side effects: hypocalcemia (most common, monitor weekly initially), nausea, vomiting.
Etelcalcetide (Parsabiv)	5 mg IV after each HD; titrate to 2.5–15 mg per session	Calcimimetic, IV alternative to cinacalcet	Better adherence than oral cinacalcet (given by dialysis nurse). Same hypocalcemia risk; monitor Ca closely.
Vitamin K1 (phytonadione)	1–10 mg PO daily	Activates matrix Gla protein	Inexpensive, low-risk. Especially useful after stopping warfarin. Avoid if patient still requires warfarin (defeats anticoagulation).
Pamidronate ADJUNCT	30–90 mg IV every 4–8 weeks	Bisphosphonate, weak evidence	Inhibits osteoclast-mediated bone resorption; may reduce vascular calcification. Side effects: hypocalcemia, osteonecrosis of jaw (rare), atypical femoral fractures. Renal dose-adjust.
Hydromorphone or methadone or fentanyl IV	Per pain protocol	Pain control	Avoid morphine in ESRD (active metabolite M6G accumulates → neurotoxicity). Avoid fentanyl patches over lesions (heat + necrotic skin). Methadone is dialyzable variably and safe in ESRD with care.
Gabapentin	100–300 mg PO at HD only or 100 mg QHS	Neuropathic pain adjunct	Renally cleared, dose carefully in ESRD (much lower doses needed). Sedation, ataxia.

📋 On Rounds

On Rounds

📋 Sample Presentation

"Ms. Reyes is a 58-year-old woman with ESRD on hemodialysis × 6 years (DM and HTN nephropathy), atrial fibrillation on warfarin, and BMI 34, admitted with 2 weeks of severely painful, expanding violaceous lesions on her abdomen and bilateral thighs. Pain is 10/10, requires PCA hydromorphone. On exam, she has multiple violaceous retiform plaques on the lower abdomen and medial thighs with central black eschars and surrounding livedo, no fever. Labs: Ca 9.8, P 6.4, PTH 540, Ca × P 63, INR 2.4, ALP 180, albumin 3.0. Bone scan shows subcutaneous tracer uptake corresponding to lesions. We have made the clinical diagnosis of calciphylaxis, started sodium thiosulfate 25 g IV after each HD, switched warfarin to apixaban, switched calcium acetate to sevelamer, started cinacalcet 30 mg daily, vitamin K1 5 mg daily, and engaged wound care, palliative care, and dermatology."

Pimp Questions

Why is warfarin a major risk factor for calciphylaxis?

Warfarin inhibits vitamin K-dependent γ-carboxylation, which activates not only clotting factors II/VII/IX/X but also matrix Gla protein (MGP), the body's primary inhibitor of vascular calcification. Uncarboxylated MGP is inactive → vascular smooth muscle freely undergoes osteoblast-like trans-differentiation → arterial media calcify. This is why apixaban (a direct factor Xa inhibitor with no effect on MGP) is preferred when anticoagulation is needed in calciphylaxis.

What is the mechanism of sodium thiosulfate in calciphylaxis?

Three proposed mechanisms: (1) Calcium chelation: thiosulfate binds free calcium to form soluble calcium-thiosulfate complexes that are dialyzable. (2) Antioxidant: scavenges reactive oxygen species, reduces vascular smooth-muscle osteoblast differentiation. (3) Vasodilation: thiosulfate is metabolized to hydrogen sulfide and other NO-related species, improving microvascular perfusion. Standard dose 25 g IV after each HD; main side effects are anion-gap metabolic acidosis, nausea, and hypotension.

A dialysis patient has a painful violaceous lesion on the abdomen. What's the differential and how do you tell them apart?

Calciphylaxis (ESRD context, painful retiform purpura, adipose-rich sites), warfarin-induced skin necrosis (days 3–10 of warfarin, protein C deficiency, breasts/buttocks, lacks ESRD requirement), cellulitis (febrile, leukocytosis, more diffuse), cholesterol emboli (recent vascular procedure, livedo + blue toes + eosinophilia), pyoderma gangrenosum (pustule → ulcer with violaceous undermined edge, IBD/RA), vasculitis (systemic features, positive serologies). The pain out of proportion to lesion size + ESRD context strongly favors calciphylaxis.

Why is biopsy controversial in calciphylaxis?

Biopsy is the gold standard (medial calcification, intimal proliferation, microthrombi on von Kossa stain), but the biopsy site itself can become a new non-healing ulcer because the surrounding skin is ischemic and hypercoagulable. For classic ESRD presentations, many centers diagnose clinically (or with bone scan, sensitivity ~90%) and treat empirically. Reserve biopsy for atypical cases (non-uremic, unusual distribution, mimics not excluded). If you do biopsy, take a punch from the edge of the lesion, not the center.

What is the prognosis of calciphylaxis?

Grim. 1-year mortality 45–80%. The leading cause of death is sepsis from infected skin ulcers. Prognostic factors: (1) Distribution, central (truncal) lesions ~80% mortality vs distal (limb) lesions ~50%. (2) Ulceration at presentation (worse). (3) Infection. (4) Total body surface area involved. (5) Time to diagnosis and treatment. Early aggressive multidisciplinary management (sodium thiosulfate, stop warfarin, stop Ca binders, control P and PTH) improves outcomes; case series report 30–50% healing with the full package.

Clinical Examples

📋 Case 1, Classic Truncal Calciphylaxis

Patient: 58F on HD × 6 years, AF on warfarin, BMI 34, DM. Painful violaceous abdominal/thigh lesions × 2 weeks.

Key findings: Multiple retiform plaques with central eschars on abdomen and medial thighs. Pain 10/10. Ca 9.8, P 6.4, PTH 540, Ca × P 63, INR 2.4. Bone scan: subcutaneous uptake.

Management:

Sodium thiosulfate 25 g IV after each HD
Switch warfarin → apixaban 5 mg BID
Switch calcium acetate → sevelamer 800 mg TID
Cinacalcet 30 mg daily, titrate for PTH 150–300
Vitamin K1 5 mg PO daily
Pain: hydromorphone PCA + gabapentin 100 mg at HD
Wound care, derm, palliative care all engaged

Teaching point: Truncal lesions carry the worst prognosis (~80% 1-year mortality). Treatment requires removing every calcification driver simultaneously, not just adding sodium thiosulfate.

📋 Case 2, Distal Calciphylaxis at Heparin Injection Sites

Patient: 64M on HD × 4 years, on enoxaparin for prior PE. New painful violaceous lesions at rotated SC injection sites on abdomen and thighs.

Key findings: Lesions correspond exactly to recent injection sites. P 5.8, PTH 380, Ca 9.4. No ulceration yet.

Management:

Sodium thiosulfate 25 g IV after each HD
Switch enoxaparin → oral apixaban (eliminate SC injections)
Optimize phosphate (sevelamer titration)
Cinacalcet for HPT
Aggressive pain control

Teaching point: Lesions appearing at SC injection sites in a dialysis patient is near-pathognomonic for calciphylaxis. Microtrauma from injections triggers calcific lesions in already-vulnerable tissue. Switching to oral or IV routes (and eliminating SC heparin/insulin/enoxaparin where possible) is part of treatment.

📋 Case 3, Non-Uremic Calciphylaxis

Patient: 49F with primary biliary cholangitis (cirrhosis, MELD 18) and primary hyperparathyroidism, no CKD. Painful violaceous breast and thigh lesions.

Key findings: Ca 11.2, P 4.8, PTH 240 (high for normal renal function), albumin 2.5. Skin biopsy confirms medial arteriolar calcification.

Management:

Sodium thiosulfate 25 g IV 3×/week (no dialysis, give as outpatient infusion)
Cinacalcet for HPT, plus parathyroidectomy evaluation
Vitamin K supplementation
Aggressive nutrition (low albumin = low fetuin-A → loss of calcification inhibitor)
Wound care; pain control

Teaching point: Non-uremic calciphylaxis exists (~10% of cases). Risk factors include primary HPT, malignancy, autoimmune disease (especially with hypoalbuminemia), and cirrhosis. Same treatment principles, but no dialysis to time the STS infusion against. Also a setting where biopsy is more important since the diagnosis is less clinically obvious than in classic ESRD.

Daily Rounds Checklist

Pain: regimen, breakthrough use, opioid-rotation needs (avoid morphine, avoid fentanyl patches)
Wound exam: extension of lesions, new lesions, signs of infection (purulence, surrounding cellulitis, fever)
Phosphate, Ca, PTH: trending; binder dose adjustments; cinacalcet response
STS tolerance: bicarb (anion-gap acidosis), nausea, BP, fluid status
Anticoagulation: confirmed off warfarin; apixaban dose appropriate for renal function
Infection screen: low threshold for cultures and broad-spectrum antibiotics
Goals of care: revisit at every transition (new lesion, sepsis, refractory pain)

🎯 Summary

At a Glance

Definition

Calcific uremic arteriolopathy: medial calcification + intimal proliferation + thrombosis of dermal arterioles → painful violaceous skin necrosis in ESRD patients.

Epidemiology

1–4% of dialysis patients/year. F:M ~3:1. Mean age 55–60. 1-year mortality 45–80%, mostly from sepsis.

Top Risk Factors

ESRD on dialysis, female, obesity, DM, warfarin, calcium-based binders, hyperphosphatemia, hyperparathyroidism, vitamin K deficiency.

Hallmark

Painful (often disproportionate) violaceous retiform purpura on adipose-rich sites (abdomen, thighs, breasts). Lesions at SC injection sites is near-pathognomonic.

Diagnosis

Clinical in classic ESRD presentation. Bone scan (Tc-99m) sensitivity ~90% for non-invasive confirmation. Biopsy is gold standard but risks non-healing ulcer at biopsy site.

Cornerstone Therapy

Sodium thiosulfate 25 g IV after each HD session, 3×/week, 3–6+ months. Chelates Ca, antioxidant, vasodilator.

Stop List

Stop warfarin (switch to apixaban), stop Ca-based binders (switch to sevelamer/lanthanum/iron-based), stop fentanyl patches over lesions, stop aggressive surgical debridement.

Targets

P < 5.5, Ca × P < 55, PTH 150–300, normal Ca. Intensify dialysis (low-Ca dialysate). Vitamin K1 1–10 mg/day.

Multidisciplinary Team

Nephrology + dermatology + wound care + palliative care + pain medicine + dietitian + surgery (if infected ulcers).

Prognostic Markers

Worse: central/truncal lesions, ulceration, infection, large surface area. Better: distal-only lesions, no ulceration, early diagnosis and full treatment package.

📄 One Pager

Calciphylaxis One-Pager

Painful violaceous retiform purpura in an ESRD patient = calciphylaxis until proven otherwise. 1-year mortality 45–80%, mostly sepsis.

Diagnosis (clinical first, biopsy if unclear):

ESRD (dialysis), painful violaceous retiform lesions on adipose-rich sites (abdomen, thighs, breasts)
Lesions at SC injection sites is near-pathognomonic
Bone scan: subcutaneous Tc-99m uptake (sensitivity ~90%)
Biopsy if atypical: medial Ca²⁺ deposition (von Kossa), intimal proliferation, microthrombi

Treatment package (do all of these together):

Sodium thiosulfate 25 g IV after each HD × 3–6+ months
Stop warfarin → apixaban 2.5–5 mg BID if anticoagulation needed
Stop Ca-based binders → sevelamer / lanthanum / ferric citrate / sucroferric oxyhydroxide
Phosphate < 5.5, Ca × P < 55, low-Ca dialysate, intensified HD
Cinacalcet or etelcalcetide for HPT; parathyroidectomy if refractory
Vitamin K1 1–10 mg/day
Conservative wound care, debride only if infected; HBOT in select cases
Pain: hydromorphone or methadone IV, gabapentin (low ESRD dose), avoid morphine and fentanyl patches
Low threshold for sepsis workup and broad-spectrum antibiotics
Palliative care early

Avoid: warfarin, Ca-based binders, IV calcium for asymptomatic hypoCa, fentanyl patches over lesions, aggressive debridement of non-infected lesions, gadolinium MRI in advanced CKD.

Calciphylaxis (Calcific Uremic Arteriolopathy)