oncological emergencies Flashcards
name the top oncological emergencies
neutropenic sepsis malignant spinal cord compression tumour lysis syndrome hypercalcaemia SVC obstruction brain metastasis and raised ICP
others: leukostasis, SiADH, bowel obstruction, hyperviscosity syndrome, complete dysphagia, hypoglycaemia, hypomagnesmia
how is neutropenic sepsis defined?
defined by:
- neutrophil count of <0.5 x10^9 cells/ L or < 1x 10^9 cells/ L and falling
- temperature of >38.5 or >38 on 2 readings for 2 hours
- OR atleast 2 signs of sepsis e.g. q SOFA >2 e.g. hypotension, tachycardia, resp rate >21, GCS <15
what is the cause of neutropenic sepsis?
occurs post chemotherapy because chemotoxic agents destroy neutrophils which increases risk of infection. often the low neutrophil count can be transient and reversible but when at lowest point there is the highest risk of infection
infection usually from endogenous flora e.g. S.aureus and S.epidermidis but source is often not identified.
how do patients with neutropenic sepsis present?
unwell, fever, confused (low MMSE) , drowsiness, tachycardia, hypotensive
(if HR > systolic BP this is worrying otherwise could just have naturally low BP)
may have symptoms related to specific infections e.g. UTI, cough.
may be signs related to source e.g. hickman line, catheter
usually presents between day 5 and 14 post chemotherapy but usually at day 7-10. but can occur anywhere up to 3 weeks post chemo.
can cause death so must be managed immediately
who does neutropenic sepsis mainly affect?
elderly, increased chemo dose, comorbidities
how is neutropenic sepsis investigated?
FBC, UE, LFTs (certain infections raise LFTs e.g. legionella), Albumin , lactate, CRP
blood cultures - take from central and peripheral line to compare growth and see if source is a line
ABG
try to find source of infection:
- dipstick/ urine cultures - midstream urine culture
- swabs from lines, wound, catheter, cannulas
- stool sample if diarrhoea
- CXR, AXR, CT, MRI
how is neutropenic sepsis treated?
IV broadspec Abx started within 1 hour
- usually tazocin (broad spec and protects against pseudomonas)
- if pen allergy use meropenem instead
- if hypotensive shock or elderly add gentamicin to tazocin
IV fluids, catherise and fluid balance monitored
Oxygen
call senior
consider GCSF for those who are profounding neutropenic
review in 48 -72 hours:
if no response - add vancomycin and continue other abx for further 48 hours. Also consider starting ambisome (antifungal) and antivirals
if apyrexic but neutrophils still low = continue tazocin for 5 days
if apyrexia and >1 WCC - stop empirical Abx
how is neutropenic sepsis prevented?
prophylactic Abx
reduce dose
warn those at risk to look out for symptoms and seek help - issue with medical alert card and 24 hour contact numbers
GCSF - granulocyte colony stimulating factor
what is the pathophysiology behind malignant spinal cord compression?
tumour within the vertebral column can cause the vertebrae to collapse and compress spinal cord OR tumour can grow into the lumen of spinal column and compress on spinal cord
tumours that metastasise to vertebrae: lung, breast, prostate, kidney, lymphoma, multiple myeloma and thyroid
initially results in oedema, venous congestion and demyelination = reversible
but eventually results in vascular injury and cord necrosis = irreversible
what are the signs and symptoms of malignant spinal cord compression?
back pain - worse on coughing, sneezing, straight leg raise
radiculopathy
pain/ sensory change/ weakness in dermatomal area
urine retention, bowel incontinence
examination
- flacid paralysis at first
- then spasticity - increased tone, clonus and hyperreflexia
- may be able to palpate full bladder if retention
what are the red flags for back pain?
BACT PAINS
B = bowel / bladder dysfunction A = age <18 or >50 C = cancer history T = temperature P = previous drug user A = anorexia/ weight loss I = injury / trauma N = neurological signs S = steroids
how is suspected spinal cord compression managed?
prompt treatment to preserve nerve function
urgent MRI of the whole spine within 24 hours
admit and bed rest
dexamethasone 16mg + PPI/ ranitidine
analgesia
bisphosphonates for breast and myeloma (and prostate if other analgesia isn’t working)
treat within 24 hours:
- surgery: (if good prognosis >3 months and good performance status)
= balloon kyphoplasty - inflate a balloon into vertebrae to stop collapse
= vertebroplasty = stop collapse
- radiotherapy:
= if surgery contraindicated, if multiple spinal metastasis and surgery is not possible.
others:
- DVT prophylaxis
- physiotherapy - improve upper body strength
- OT if paralysed and need house adjustment
what is the criteria for MRI for spinal metastasis and spinal cord compression?
pain suggestive of spinal metastasis - MRI within 1 week
signs of cord compression - MRI in 24 hours
how can malignant spinal cord compression be avoided?
prophylactically can perform balloon kyphoplasy surgery to hold vertebrae in place.
high risk patients warned of symptoms and asked to seek help ASAP
what are the prognostic indictors after spinal cord compression?
good performance status few comorbidities good motor function at present long time since primary diagnosis one spinal level absence of visceral metastasis lymphoma, multiple myeloma, breast, prostate, renal
what are the side effects of ambisome ?
antifungal
side effects include anaphylaxis and nephrotoxic (monitor UEs)
when is superior vena cava obstruction an emergency?
when it causes airway compromise
what are the causes of SVC obstruction?
mainly small cell lung cancer (extrinsic compression)
also my mediastinal lymphoma
or other causes of mediastinal enlargement - thymus malignancy, germ cell tumour
goitre and aortic aneurysm
SVC thrombosis
what are the signs and symptoms of SVC obstruction?
dyspnoea - main symptom
orthopnoea , cough
swelling: periorbital oedema, facial oedema, distended neck and thoracic veins, arm swelling
feeling of head fullness, pulsation, choking sensation
headache, visual disturbances ,lethargy
what signs are seen in SVC obstruction?
pemberton test - raise arm above head for 1 min - causes facial plethora and cyanosis
raised JVP
inspiratory stridor - late sign
what investigations could be done to confirm SVC obstruction?
CXR - enlarged mediastinum
CT with contrast - shows extrinsic compression
venography
how is SVC obstruction managed?
O2 and elevate head of bed
oral dexamethasone and PPI
refer to cardiothoracic team for balloon venoplasty or SVC stenting.
if cant stent then chemo/radiotherapy. if unstable, no time to wait for chemo, so do radiotherapy.
where in spinal column do majority of malignant spinal cord compressions occur?
thoracic region
what are the causes of hypercalcaemia in malignancy?
squamous cell lung cancer and PTHrP
lytic bone metastasis - renal, breast
lymphoma (adult T cell) secreted Vit D
myeloma
what does hypercalcaemia tell you about prognosis?
poor prognosis
suggests cancer progression
what are the symptoms of hypercalcaemia?
moans:
- lethargy, muscle weakness, confusion, bone pain, pruritic
groans:
- constipation, N&V, anorexia
stones:
- renal stones, polyuria, polydipsia
can lead to coma and death.
what investigations should be done for hypercalcaemia?
serum ionised calcium UEs ALP albumin - low albumin can interfer with Ca levels Xrays and bone scans.
how is hypercalcaemia managed?
fluid regime:
- IL in 2 hour
- IL in next 4 hours
- I L in next 6 hours (check with local policy)
- catheterise and monitor fluid balance
- look for signs of overload (oedema, raised JVP, crackles)
recheck bloods - especially UEs (because may give bisphosphonates and these can cause renal failure so must be well hydrated)
if Ca still high give IV zoledronic acid or IV pamidronate (if renal impairment adjust the dose)
treat underlying malignancy
recheck Ca
what causes raised ICP in malignancy?
brain metastasis (lung, breast, myeloma) primary brain tumours)
what are the signs of brain mets/ raised ICP?
headaches - worse with coughing, in morning and leaning forward N&V visual changes, papilloedma cranial nerve palsy cerebellar signs personality/ behavioural changes seizures focal neurological signs bradycardia is a late sign
what are the cerebellar signs?
DANISH
- Dysdydokinesis
- ataxia
- nystagmus
- intention tremor
- slurred speech
- hypotonia
what investigations should be done if you suspect brain mets?
MRI/ CT brain
usually CT because needed quickly
- this will tell us if there is a mass, haemorrhage within tumour, hydrocephalus due to shunt blockage or cerebral oedema
how are brain metastasis / raised ICP managed?
IV dexamethasone 8mg if 3 or less lesions - curative - surgery and then targeted radiotherapy if >3 lesions - palliative - whole brain radiotherapy
mannitol for cerebral oedema
lorazepam/ phenytoin for seizures
what is the prognosis for brain metastasis?
1-2 months
what is leukostasis?
high white cell count + symptomatic
occurs in acute myeloid leukaemia mainly (also ALL)
how do people with leukostasis present/ complications?
high fever respiratory failure papilloedema, retinal vein bulging, retinal haemorrhage intracranial haemorrhage focal neurological signs MI limb ischaemia renal vein thrombosis DIC
how is leukostasis managed?
rapid cytoreduction (reduce cells) by initiating chemo (however at higher risk of TLS)
cytoreduction can also be achieved by hydroxyurea (if chemo cant be started)
leukophoresis can be used if blast count is very high
how does SiADH present?
often asymptomatic depression , lethargy irritable and behavioural changes muscle cramps seizures, reduced consciousness, coma
what electrolyte is abnormal in siADH
hyponatraemia
how is siADH managed?
treat malignancy
fluid restriction
what is the cause of tumour lysis syndrome?
rapid death of cells due to chemotoxic agents results in release of K, urate, PO4
PO4 precipitates with Ca - hypocalcaemia
uric acid and the CaPO4 can cause nephropathy and AKI
most common with rapidly proliferating leukaemias, lymphomas, myeloma (also germ cell tumours and small cell lung cancer) which are very chemo sensitive
can also occur following radiotherapy
which patients are most at risk of TLS?
those with renal impairment, live impairment, hypovolaemia/ diuretic use, urinary tract obstruction from tumour, pre-existing LDH, pre-existing high urea
what are the complications of TLS?
high K, high PO4, high urea, low Ca
AKI
seizures
arrhythmias
what are the clinical features of TLS?
normally presents 3-7 days post chemo N&V, diarrhoea, lethargy muscle weakness, tetany, seizures, haematuria, oliguria/ anuria syncope
how is TLS treated?
monitor serum urate, lactate, UEs, LDH and fluid balance. ECG - monitor arrhythmias
good hydration (ensure no K in fluids)
allopurinol (inhibits xanthase oxidase)
IV rasburicase (if at high risk) (causes uric acid to be converted to allantoin which is water soluble and excreted
treat complications:
- hyperK = calcium gluconate and insulin
- hypoCa = calcium gluconate
- high PO4 = phosphate binders, restrict in diet
- haemodialysis if renal failure
how is TLS prevented?
low risk = monitor electrolytes and fluid status
medium risk = alloruinol for 7 days before chemo + hydration
high risk = rasburicase and hydration
what is hypomagnesmia caused by?
GI loss - malabsorption - tumour, post surgical - inadequate intake - N&V - loss - diorrhoea , vomiting renal loss - nephrotoxic chemo - diuretics (loop, thiazides) - hypercalcaemia (competition for transport)
what are the symptoms of hypoMg?
confusion, coma
arrhythmia
ileus
muscle fatigue, weakness
