Carcinoid crisis explained
Sometimes, individuals with NETs experience a severe bout of something called carcinoid syndrome. Stress, certain medical procedures, or specific treatments can trigger it. This is referred to as a ‘carcinoid crisis.’
The symptoms are intense, and can include:
- Sudden redness in the face
- Stomach issues (upset stomach)
- Strong abdominal pain
- Difficulty breathing
- Rapid heartbeats
- Changes in blood pressure
- Diarrhoea
- Wheezing
In extreme cases, it can lead to confusion or even a coma. Your NET specialist will ensure you are monitored during procedures (including dental work and anaesthetics), in which you may be susceptible to these symptoms and may give you medication to prevent such a crisis occurring (e.g. an infusion of a somatostatin (octreotide) analogue).
If you’re at risk for carcinoid crisis, it is important to inform your clinician and you can carry a small card from the NeuroEndocrine Cancer Australia website. It’s not just for show – it alerts healthcare professionals about carcinoid crisis and how to manage it.
Anaesthesia and NET patients
Individuals with NETs can safely undergo different kinds of anaesthesia, like general anaesthesia, local anaesthesia, or even sedation to help them relax. The key is having an anaesthesia team that’s familiar with managing a carcinoid crisis.
This crisis can be a concern during various procedures, big or small, affecting around 20–30% of surgeries – even dental ones. That’s why choosing medical centres experienced in treating NET patients is crucial.
Signs of carcinoid crisis
A carcinoid crisis is marked by certain signs, like sudden low or high blood pressure causing instability, a fast heartbeat, flushing of the skin, asthma-like breathing issues (bronchospasm), or a rise in body temperature.
Risks and triggers of carcinoid crisis
Factors that make someone more prone to a carcinoid crisis include having a significant amount of tumour growth (especially in the liver), high levels of specific substances in the body, or issues with the heart due to the tumours.
Different things can set off a carcinoid crisis, like:
- Surgeries and specific treatments
- Feeling anxious or stressed
- Receiving anaesthesia
- Feeling very cold during surgery
- Taking certain drugs that can cause a reaction
It’s hard to predict which patients might be at risk for a carcinoid crisis during surgery. So, the anaesthesia team has to be ready for it just in case.
Octreotide (somatostatin analogue) to prevent carcinoid crisis
To help prevent and manage a carcinoid crisis, a medicine called octreotide is used. It stops certain hormones from being released and slows down tumour growth.
Octreotide is a type of somatostatin analogue – it puts a stop to the release of growth hormones, glucagon, insulin, and similar hormones. It also attaches to certain receptors, specifically type 2, 3, and 5 somatostatin receptors, on neuroendocrine tumours. By doing this, it actually slows down the growth of these cells.
Octreotide doesn’t work very well if swallowed. It’s instead delivered through a needle either into your vein (intravenous), your muscle (intramuscular), or under your skin (subcutaneous). During surgery, octreotide is given through a vein. It’s stable and doesn’t break down easily in solutions like normal saline, water, or even a 5% sugar solution called dextrose. Octreotide can be delivered in one injection or as a steady drip medication to get the best results.
When octreotide is put under your skin, it’s absorbed quickly. It reaches its highest concentration in your blood about 20–30 minutes after the injection. Importantly, it sticks around in your body for about 60–90 minutes before it starts to lose effectiveness – the half-life of the drug.
Your liver plays a significant role in getting rid of octreotide (about 65% of it), and your kidneys also help flush it out. If your kidneys aren’t working well, it might take a bit longer for your body to clear out the octreotide.
People who are already taking long-acting octreotide treatments like Sandostatin LAR or Lanreotide might need higher doses of octreotide during surgery. This might be because their bodies are getting used to the drug over time (called tachyphylaxis), so higher amounts are needed to get the same effect.
Information that may assist your treatment team
Pre-operative
- Full preoperative work-up including cardiac investigations for carcinoid heart disease
- Correct electrolyte abnormalities, dehydration and pre-existing protein abnormalities
- Appropriate monitoring (arterial pressures, central venous pressures).
Pre-medication
- Octreotide 100–1000 μg as bolus then 100–1000 μg/hr infusion (titrated to effect)
- Antihistamines
- H1 antagonist – diphenhydramine, loratadine, etc.
- H2 antagonist – ranitidine, famotidine
- Benzodiazepines
- Midazolam, diazepam etc.
Intra-operative
- Octreotide – continue infusion at 100–1000 μg/hr with boluses when indicated
- Avoid drugs that have a potential for histamine release
- Eg. morphine, pethidine, codeine, atracurium, mivacurium
- Effective blunting of the pressor response to intubation and maintenance of depth of anaesthesia
- Prepare for periods of potential carcinoid crisis during manipulation of tumour.
Management of carcinoid crisis haemodynamic instability
- Bolus doses of octreotide 100–1000 μg
- Use of crystalloids or colloids to expand intravascular space whilst avoiding right ventricular overload or strain.
- Use of vasoconstrictors – phenylephrine, metaraminol, noradrenaline (low doses)
- Adrenaline has the potential to cause more release of vasoactive peptides
- Monitor fluid balance, temperature and blood sugar levels
Post-operative period
- Continue octreotide infusion and wean over days
- Monitor in a high dependency or intensive care setting
- Ensure good pain control with regional techniques; neuraxial blockade; patient controlled analgesia (PCA)
Patients who are at risk of carcinoid crisis should engage in open and proactive communication with their healthcare team to ensure their safety and well-being. If you’ve had a recent NET diagnosis, it is vital to inform your healthcare providers about your specific medical history, including any previous episodes of carcinoid crisis, triggers, and symptoms you’ve experienced.
We always recommend discussing your current medications, including any prescription drugs, over-the-counter medications, or supplements, as certain substances can potentially induce or worsen a crisis.
Establish a clear action plan with your healthcare team, which includes instructions on how to recognise the early signs of a carcinoid crisis and what immediate steps to take if one occurs. Regularly follow up with your healthcare team for ongoing monitoring, adjustments to your treatment plan, and to address any concerns or questions.
