Fluids electrolytes nutrition

Question 1

What is the evidence for TPN in terminal patients with MBO

Answer 1

Low benefit for survival and quality of life. Varying definitions of survival ranging 15-155 days

Question 2

Discuss causes and cancers a/w hypercalcemia of malignancy

Answer 2

Hypercalcemia is considered when serum calcium levels reach > 10.5 mg/dL
When >14 mg/dL it is considered a major emergency!

Etiology
Humoral hypercalcemia of malignancy– 80% of cases
Parathyroid hormone-related protein (produced by many solid tumors) acts like PTH, results in increased renal and bone reabsorption of calcium

Local osteolytic hypercalcemia– 20% of cases
In bone metastases– tumor cells produce various cytokines that lead to calcium reabsorption
Active osteoclasts at tumor site lead to bone breakdown and higher calcium levels

Higher risk in: Solid tumor with bone metastases, Breast
Lung, Prostate, Liquid tumor, Multiple myeloma, Lymphoma

Question 3

How do you manage hypercalcemia of malignancy

Answer 3

All patients:
IV hyperhydration of NSS at 200ml/hr: Increases glomerular filtration rate, Increases filtration of calcium, Add loop diuretics as needed for fluid management

Medications
Bisphosphonates (pamidronate over zolendronic acid): Block osteoclast action, Therapeutic effect 48 hours after therapy, 4mg IV over 15 minutes, Caution in renal failure or insufficiency (Excreted by kidneys, Exacerbates kidney failure)

Calcitonin : Inhibits osteoclasts in bone and increases urinary excretion of calcium