Case 31 - Carcinoid syndrome Flashcards

1
Q

What is carcinoid tumor?

A
  • neuroendocrine tumor
  • typically found in appendix, ileum, and rectum; able to metastasize
    • can find in lung too
  • secrete various bioactive substance: serotonin, histamine, bradykinin, etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how do you diagnose carcinoid tumor?

A
  • 5-HIAA urine and plasma level
    • metabolite of serotonin

Imaging studies

  • help locate primary tumor
  • look for mets

Bronch

  • useful for tumors located in bronchial tree
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

patient has diagnosed carcinoid tumor. How does he get carcinoid syndrome?

A
  • although carcinoid tumors secrete bioactive substances, tumors that drain into portal system (like tumors of GI tract) will have these substances metabolized by the liver.
  • Tumors that secrete substances that do NOT drain into portal circulation -> bypass hepatic metabolism, and enter systemic circulation –> see bioactive substance effect –> carcinoid syndrome

Liver Mets

  • large tumors secrete so much bioactive substance, that overwhelms liver’s ability to inactive it –> released into system circulation = s/sx of carcinoid syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the clinical featurs of carcinoid syndrome?

A

s/sx 2/2 to bioactive substance release into circulation

Triggers of sertonin/histamine release:

  • stress, exercise, alcohol, coffee
  • serotonin rich food - bananas, avocados, eggplant, kiwi

serotonin/histamine effects

  • cutaneous flushing
  • hypertension vs hypotension
    • some substances vasodilate, others vasoconstrict. Labile BP as a result
  • diarrhea; n/v
  • abdominal pain
  • wheezing/bronchospasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Is carcinoid syndrome associated with cardiac abnormalities?

A
  • right side valvular lesions
    • tricuspid stenosis or regurg
    • pulmonary stenosis or regurg
    • possibly due to valvulitis and fibroblast proliferation (fibrous tissue and scarring)
  • right sided CHF as a result
    • hepatomegaly, lower extrem periph edema, JVD
  • rare to cause left valvulopathy due to metabolism of bioactive substances by lung
  • fibrous tissue growth of electrical pathways –> arrhythmias
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is carcinoid crisis?

A
  • life threatening form of carcinoid syndrome
  • severe flushing, labile BP, cardiac arrhythmias, bronchoconstrict, mental status change, CV collapse

Pathology

  • due to sudden release of excessive amts of tumor mediator substances

Triggers

  • anxiety, pain
  • hypoxia/hypercarbia
  • hypothermia
  • tumor manipulation
  • catecholamine releasing agents
  • histamine releasing agents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the tx for carcinoid crisis

A
  • due to sudden release of excessive amounts of tumor mediator substances

Tx:

  • tell sx to stop manipulating tumor
  • IV Fluids
  • octreotide
  • H1 & H2 receptor blockers
  • phenylephrine/vasopressin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are your concerns when a patient with carcinoid shows up to your OR?

A

1) history and physical for s/sx of carcinoid syndrome

  • tells you that tumor mediator substances have access to systemic circulation
  • diarrhea, wheezing, heart murmur
  • CBC (GI bleeding?), CMP (dehydration, electrolyte derangements), glucose (serotonin causes hyperglycemia)

2) Heart disease - ECHO & EKG

  • right side valvular disease –> CHF
    • valvular lesions 2/2 serotonin induced fibrous tissue growth of valves
    • pulm HTN vs regurg, TR
  • fibrous growth of endocardium –> electrical pathways –> arrhythmias

3) diarrhea; N/V

  • Dehydration
  • metabolic derangements

4) Wheezing/bronchospasm

  • responsive to beta 2 agonists?
  • need to optimize
    • octreotide
    • steroids
    • ipratropium
    • **antihistamines **
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is somatostatin?

A
  • endogenous substance
  • inhibits GI motility, gastic acid production, inhibits tumor mediated substance release
  • **effective in tx carcinoid crisis**

somatostatin vs octreotide

  • octreotide = synthetic analogue of somatostain
    • lasts longer, different routes of admin (sub-q, iv injection, continuous infusion)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is your pre-operative management for carcinoid tumor pts?

A
  • Avoid triggering factors that provoke carcinoid crisis.
  • correct HD instability, intravascular depletion, bronchospasm, and electrolyte imbalances preoperatively
    • ​consider starting octreotide pre-op
  • BZD and antihistamine
    • anxiety can trigger carcinoid crisis

Lines:

  • large bore perpheral IV access
  • pre-induction arterial line
    • labile BP, triggers of carcinoid crisis can occur with induction and intubation
  • CVC
    • fluid shifts, vasoactive therapy
  • PAC vs TEE
    • dependent on presence and extent of cardiac involvement
    • TEE - CO, volume status, valvular pathology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

is neuraxial anesthesia contraindicated for carcinoid patients?

A

Neuraxial anesthesia

  • spinal anesthesia can exacerbate hypotension
  • epidural - better option
    • carefully titrate to avoid hypotension
    • dosing is more controlled
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What anes meds trigger carcinoid crisis?

A
  • Avoid triggering factors that provoke carcinoid crisis.
  • **AVOID meds that cause histamine release or stimulate autonomic nervous system **

meds that trigger

  • morphine
  • mepridine (increase HR, histamine release)
  • ketamine
  • atracurium

Safe:

  • antihistamines
  • fentanyl, remifent
  • prop, etomidate
  • vec, roc, cis-at
  • volatile agents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the management of carcinoid syndrome intra-op?

A

1) Bronchospasm

  • monitor airway pressure
  • avoid hypoxia and hypercarbia
  • octreotide tx as necessary

2) temp
* avoid hypothermia (trigger)
3) hypotension

  • fluid resucictation
  • octreotide tx as neccesary
  • tell sx to stop manipulating tumor (may be the cause)
  • vasopressor (phenylephrine, vasopressin)
    • epi, norepi, dopa (worsen hypotension by triggering vasoactive mediator release)

4) HTN

  • octreotide tx
  • deepen anesthesia
  • opioids
  • esmolol
    • NTG and SNP may trigger release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the post-op management of carcinoid syndrome?

A
  • ICU monitoring
    • some remaining functional undetected mets
      • ​need to continue to avoid triggers - hypoxia, hypercarbia, hypothermia
    • vasoactive mediators remain in circulation for a while –> still can cause s/sx of carcinoid syndrome –> need close monitoring
    • elevated serotonin levels delay emergence
  • continue octreotide infusion
  • Pain
    • opioids
    • Epidural
  • PONV
    • zofran (serotonin antagonist)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly