Procedure prep
Fasting Before Liver Resection (Hepatectomy)
A liver resection (hepatectomy) removes part of your liver, most often to take out a tumour, and is done under a general anaesthetic. It is major surgery, but it is carefully planned, and following the fasting and preparation steps below helps your team keep you safe and recover well.
Fasting for this procedure
→ Get your exact fasting times with the calculator
Medicines to check
- Blood thinners need careful planning. Drugs such as warfarin, apixaban, rivaroxaban or clopidogrel are usually stopped several days beforehand because the cut surface of the liver can bleed; never stop them on your own — follow the plan on our medications to stop before surgery page and your surgeon's instructions.
- The liver itself makes your clotting factors, so your team will check your clotting (INR) and may give vitamin K, and they decide the safe timing for any blood-thinner to restart after surgery — do not resume it until they say so.
- Diabetes medicines change while you fast. Tablets like metformin and insulin doses are adjusted on the day; see our diabetes tablets before surgery guide and confirm your exact plan with the team.
- Bring a full list of everything you take, including herbal remedies, fish oil, turmeric and supplements, as some increase bleeding and may need stopping a week or more before.
- Some blood pressure tablets are held on the day of surgery. In particular, ACE inhibitors (such as ramipril, lisinopril or perindopril) and ARBs or 'sartans' (such as losartan, candesartan or valsartan) are often not taken on the morning of major surgery, because they can cause a big drop in blood pressure during the operation — which matters in liver surgery, where keeping pressures controlled helps limit bleeding. Do not assume; ask your team which of your blood pressure tablets to take and which to skip.
- Take your other regular medicines as advised — many, such as most heart, thyroid, anti-seizure and reflux tablets, are continued with a small sip of water on the morning of surgery, but always follow the specific 'take' or 'hold' instruction your pre-assessment team gives for each one.
When this surgery may be delayed
- A chest infection, cough or any new illness in the days before — anaesthesia for major surgery is safer once you are well.
- Abnormal clotting or a low platelet count on your pre-op blood tests, which may need correcting first because liver surgery carries a real bleeding risk.
- Signs that the remaining liver may be too small or not healthy enough — sometimes scans or liver function tests prompt a rethink, or a vein-blocking procedure to grow the future liver first.
- No intensive care or high-dependency bed available, as many liver resections need close monitoring overnight after the operation.
- You did not follow the fasting instructions and have eaten or drunk too recently, which makes the anaesthetic unsafe.
Reports & documents to carry
- All your scans and reports — CT, MRI, ultrasound and any PET scan of the liver — or confirmation the hospital already has them.
- Recent blood test results, especially liver function, clotting/INR and any tumour markers, if you hold copies.
- A complete, up-to-date list of your medicines and doses, including blood thinners, supplements and herbal products.
- Details of past surgery, anaesthetics and any reactions, plus any clinic or MDT (team meeting) letters about your treatment plan.
- Your hospital admission letter, ID and a packed bag for a longer stay, as recovery from liver resection usually takes several days to a week or more in hospital.
What to ask your anesthesia team
- How much of my liver are you removing, and will the part that remains be enough to work normally?
- Will I wake up in intensive care or a high-dependency unit, and roughly how long will my whole hospital stay be?
- Will I have drains, tubes or an epidural for pain afterwards, and when are they usually removed?
- Exactly when should I stop my blood thinner before surgery, when is it safe to restart given that my liver affects clotting, and which of my blood pressure tablets should I hold on the morning?
- Are you using an ERAS recovery pathway, and what carbohydrate drinks or fasting timings do you want me to follow?
Your prep checklist
Tick things off as you sort them — saved on this device only, nothing is sent anywhere.
A general guide — your hospital's own instructions always come first.
Frequently asked questions
Why is fasting and clotting taken so seriously for liver surgery?
Two reasons. First, the general anaesthetic relaxes the muscles that normally stop stomach contents entering your lungs, so an empty stomach protects you while you are asleep. Second, the liver is where your body makes most of its clotting factors, and its cut surface can bleed during surgery. Your team checks your clotting beforehand and times any blood thinners carefully, so following the fasting and medication instructions directly affects your safety.
Will I need intensive care after a liver resection?
Often, yes. Many people spend the first night or two in an intensive care or high-dependency unit so nurses can monitor your blood pressure, breathing, fluids and liver function very closely after major surgery. This is routine and planned, not a sign something has gone wrong. You will usually have one or more drains near the wound, possibly an epidural or other pain relief, and a urinary catheter, all of which are removed step by step as you recover.
How long will I stay in hospital and recover?
Liver resection is major surgery, so most people stay in hospital for roughly five days to over a week, depending on how much liver was removed and how you heal. Recovery pathways (ERAS) help you eat, drink and move sooner, which shortens this. At home, full recovery and getting your energy back can take several weeks to a couple of months. The liver has a remarkable ability to regrow, so the part that remains gradually takes over the work.
Can I drink the carbohydrate loading drink even though I am fasting?
Yes — if your liver unit gives you a specific carbohydrate drink as part of an ERAS plan, it is designed to be taken during the fasting window and is safe to finish at the time they state, usually around two hours before surgery. It counts as a clear fluid, not food. Stick to the exact timing and amount they give you, and do not add any other food or milky drinks unless told otherwise.