AKI in a patient with known multiple myelomaJames AlvaPGY-1

Learning objectives

• To understand the various causes of AKI, and how to identify pre-renal vs intrinsic renal.

• To identify the possible sources of AKI in patients with Multiple myeloma, and their pathogenesis.

HPI• 76 y/o F with PMH of IgG multiple myeloma on

velcade/decadron, CHF (EF 30%), CAD, MI s/p PCI• P/w • Diarrhea x 2 months. Non-bloody• Vomiting x 1 day. Non-bloody, non-bilious.• Generalized malaise x 2 days• Abnormal clinic results

• BUN/Cr: 15/2.25• Baseline Cr: 1.08

History• PMH:• IgG MM• NSTEMI s/p PCI• CHF 30%• HLD

• Medications• Coreg: 6.25 mg BID• Lipitor: 40 mg once daily• Plavix 75 mg once daily• ASA 81 mg once daily• Lisinopril 5 mg once daily• Nitroglycerin PRN chest pain

• Allergies: NKA• Social: Denies smoking. Social drinking (rare), no recreational drugs• ROS: Negative

Physical exam• Vitals:• T: 36.5• HR: 125• BP: 98/67• RR: 16• O2 sat: 98

• General: Well appearing, NAD• Neuro: AOx3• Neck: Supple, no JVD, trachea midline• Cardio: Tachycardic. Normal S1, S2, no m/r/g• Lungs: CTAB, no r/w/r• Abdomen: Obese, soft, non-tender, non-distended• Extremities: Full ROM, 5/5 UE, LE, trace edema

Labs/Imaging• CBC• WBC:5.83, H/H: 10.6/32.3, Plt:337

• Chem• Na:142, K:3.3, Cl:106, Bicarb:22, BUN/Cr: 17/2.38• GFR: 24, Ca: 9.4

• U/A: Neg.• Urine chem: Na: 28, K: 13.1, Cl: 45, Cr: 60.5• Osm: 202

• Renal ultrasound: Unremarkable. No obstruction

AKI• Definition• RIFLE: Increase in serum Cr > 50% over < 7 days• AKIN: Increase in Cr: > 50%

• OR increase in serum Cr: 0.3 mg/dl in < 48 hrs.• KDIGO: Increase in Cr > 0.3 mg/dl over 48 hours

• OR > 50% increase over 7 days

• Various staging within each criteria

Types of AKI

Calculations• FENA: (Una)/(Pna)/(Ucr)/(Pcr) x 100• 0.78% Pre-renal

• BUN/Cr ratio• 7.14 Intrinsic

Causes of AKI• Prerenal• Hypovolemia, CHF, medications, hypotension, Renal artery

obstruction, cirrhosis• Intrinsic renal• Tubular disease (ATN), glomerular disease, vascular disease,

malignancy, interstitial disease• Postrenal• Urethral obstruction, obstruction of solitary kidney, obstructing

neoplasm, retroperitoneal fibrosis, ureteral obstruction*

Multiple myeloma• Common findings• African American• IgG, IgA• Anemia• Renal failure*• Recurrent infections

• Decreased normal immunoglobulins• Cord compression

• Plasmacytoma or spinal fractures

Multiple myeloma renal disease

• Renal failure may be initial manifestation• >2.0 mg/dl in 20%• Causes:

• Light chain cast nephropathy (myeloma kidney)• Direct damage and occlusion in ascending loop of henle

• Tamm-Horsfall mucoprotein

• Amyloidosis• Light chains taken up and metabolized by macrophages, secreted, and

precipitate: Congo red-positive B-pleated fibrils.• Monoclonal immunoglobulin deposition disease• Light chain/heavy chain fragments. Congo red negative.

• Renal tubular dysfunction• Reabsorption and accumulation of light chains in proximal tubular cells.

Fanconi syndrome. Exacerbates light chain cast nephropathy.• Other causes

Other causes• Hypercalcemia

• 15% of patients >11.0 mg/dl at diagnosis• Renal vasoconstriction via intratubular calcium deposition.• Nephrogenic diabetes insipidus

• Reversible

• IV radiocontrast• Rare. 1.5% of pts• Due to Hypovolemia and light chain deposition• Interaction between contrast and light chains

• Drugs• NSAIDs• Bisphosphonates

• Assd. With ATN and focal/segmental glomerulosclerosis• Bortezomib

• Treatment for myeloma kidney, but may be assd. With other causes of renal failure• RARE. Bilateral hydronephrosis, nephrolithiasis, renal failure.

• Lenalidomide• Renal failure 4-10% of pts.

• Lisinopril• Elevated BUN/Cr common. AKI rare.

Labs cont.• Immunoglobulins:• IgA: 70• IgM: 60• IgG: 807

• Free light chains• Kappa: 12.4• Lambda: 16.6

• C. Dif: Neg.

Intervention• Patient given 2 L IV fluids in ER, 1 L as inpatient• Lisinopril d/c• Loperamide started• Creatinine (1.08 baseline)• Cr: 2.38 1.71 1.68

• AKI 2/2 to hypovolemia• Prolonged hypovolemia, hypotension, CHF ischemic injury

pre-renal, intrinsic renal failure findings

References• Agabegi, Steven S., Elizabeth D. Agabegi, and Adam C.

Ring. Step-up to Medicine. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2013. Print.

• Cline, David. Tintinalli's Emergency Medicine: Just the Facts. New York: McGraw-Hill, 2013. Print.

• Leung, Nelson. "Types of Renal Disease in Multiple Myeloma." Types of Renal Disease in Multiple Myeloma. N.p., n.d. Web. 13 Sept. 2015. <http://www.uptodate.com/contents/types-of-renal-disease-in-multiple-myeloma>.