Pertinent History

This patient is a 65 year-old-male with a past medical history (PMH) of diabetes mellitus (DM), coronary artery disease (CAD) s/p left anterior descending artery (LAD) stent who was recently diagnosed with diffuse large B-cell lymphoma (DLBCL), the most common variety of Non-Hodgkin’s Lymphoma (NHL) He presented with generalized fatigue, muscle cramps, nausea, difficulty urinating, and palpitations. He initiated R-CHOP* chemotherapy 3 days ago. Since then, he has had nausea, generalized fatigue and muscle cramping. Today he also noticed difficulty urinating and sensations of “his heart flip-flopping.” He denies any chest pain, shortness of breath or syncope. He denies any fevers or chills, cough or changes in bowel habits. *Rituximab, cyclophosphamide, hydroxydanorubicin, Oncovin (vincristine) and prednisone.

Pertinent Physical Exam

Except as noted below, the findings of the complete physical exam are within normal limits.

Pertinent Test Results

Lab results
Test	Results	Units	Normal range
WBC	4.3	K/uL	3.8–11.0 103 / mm3
Hgb	8.9	g/dL	(Male) 14–18 g/dL (female) 11–16 g/dL
Platelets	35	K/uL	140–450 K /uL
BUN	23	mg/dL	6–23 mg/dL
Creatinine	2.4	mg/dL	0.6–1.5 mg/dL
Potassium	7.4	mEq/L	3.5–5.5 mEq/L
Chloride	105	mEq/L	96–112 mEq/L
Bicarbonate	21	mEq/L	21–34 mEq/L
Glucose	145	mg/dL	65–99 mg/dL
Calcium	6.5	mg/dL	8.6–10.5 mg/dL
Troponin	<0.01	ng/ml	< 0.04
Uric acid	12.1	mg/dL	3.5–7.7 mg/dL
Phosphate	6.2	mg/dL	2.2–4.6 mg/dL

Emergency Department Management

Based on the patient’s History and Physical exam findings, concern for electrolyte imbalance due to Tumor Lysis Syndrome (TLS) is suspected. With patient history of CAD and palpitations, cardiac work up was also ordered. Electrolytes, EKG, and Complete Blood Count were ordered. EKG was found to have peaked T-waves concerning for hyperkalemia. Hyperkalemia treatment was initiated including calcium gluconate and bicarbonate.

Labs returned confirming hyperkalemia and revealing also hypocalcemia and acute kidney injury (AKI) with elevated creatinine. Patient was given insulin and D5 0.9% Normal saline boluses to treat hyperkalemia and AKI. Further labs including phosphate and uric acid were ordered. The oncology team was consulted for inpatient admission and management.