Oncogenic Emergencies Flashcards
What are the normal serum levels of Ca?
- 2-2.7mmol/L
- 7-3.7mmol/L requires treatment in order to avoid renal damage.
Levels >3.7mmol/L = emergency situation, may cause cardiac arrhythmias/arrest.
Common in lung, breast and prostate cancer.
Ca levels of what require treatment in order to avoid renal damage?
.2-2.7mmol/L
2.7-3.7mmol/L requires treatment in order to avoid renal damage.
Levels >3.7mmol/L = emergency situation, may cause cardiac arrhythmias/arrest.
Common in lung, breast and prostate cancer.
Ca levels of above what are classed as an emergency situation?
.2-2.7mmol/L
2.7-3.7mmol/L requires treatment in order to avoid renal damage.
Levels >3.7mmol/L = emergency situation, may cause cardiac arrhythmias/arrest.
Common in lung, breast and prostate cancer.
Hypercalcaema is common in what?
.2-2.7mmol/L
2.7-3.7mmol/L requires treatment in order to avoid renal damage.
Levels >3.7mmol/L = emergency situation, may cause cardiac arrhythmias/arrest.
Common in lung, breast and prostate cancer.
80% of hypercalcaemia cases are due to what?
80% due to bony mets.
Tumour cells interfere with normal balance between osteoclasts (bone breakdown) and osteoblasts (bone building).
Tumour cells secrete cytokines - IL-1, IL-6, TNF, PTHrP - which cause the activation of osteoclasts –> osteolytic bone lesions –> hypercalcaemia.
How do tumour cells interfere with bone balance?
80% due to bony mets.
Tumour cells interfere with normal balance between osteoclasts (bone breakdown) and osteoblasts (bone building).
Tumour cells secrete cytokines - IL-1, IL-6, TNF, PTHrP - which cause the activation of osteoclasts –> osteolytic bone lesions –> hypercalcaemia.
What does hypercalcaemia present as clinically?
The increased serum Ca impairs the reabsorption function of kidney tubules (reduces the sensitivity to ADH) which causes salt-losing diuresis —> polyuria and polydipsia.
Also: Abdo pain N+V Drowsiness/confusion. Impaired consciousness Cardiac arrhythmias Severity of symptoms depends on serum Ca level.
If untreated –> dehydration, renal failure and coma.
How is hypercalcaemia managed?
- Attempt to rid the body of calcium.
- Protect/improve renal function.
- Reduce bone breakdown
- Main treatments are: rehydration and bisphosphonates.
Why is rehydration used to treat hypercalcaemia?
Many of the symptoms are due to dehydration.
Rehydration temporarily reduces Ca levesls.
If the renal + cardiac function are OK, give 3L IV fluids over 24 hours. (slower if impaired function).
Why do bisphosphonates play a role in hypercalcaemia management?
Interfere with osteoclast activity and hence inhibit calcium release from bone & inhibit bone resorption.
They take 3-5 days to have maximal effect on Ca level.
The effect is maintained for ~3 weeks and some patients need regulat bisphosphonates (IV or Oral) to manage condition.
What symptoms of hypercalcaemia are slow to resolve after treatment?
Confusion.
What is neutropenic sepsis?
Neutropenic sepsis is a potentially fatal complication of anticancer treatment (particularly chemotherapy). Mortality rates ranging between 2% and 21% have been reported in adults. Aggressive use of inpatient intravenous antibiotic therapy has reduced morbidity and mortality rates and intensive care management is now needed in fewer than 5% of cases in England.
Systemic therapies to treat cancer can suppress the ability of bone marrow to respond to infection. This is particularly the case with systemic chemotherapy, although radiotherapy can also cause such suppression.
What is neutropenia?
Low neuts.
<1.5x10^9/L
Caused by: chemotherapy, radiotherapy, diseases with bone marrow involvement.
Neutropenia increases the risk of serious infection.
Most bacterial neutropenic sepsis cases are what?
G+ve, most pathogens are part of the host’s own gut or skin flora.
Prolonged neutropenia increases what?
The risk of fungal infections.
