Your surgeon has just said the operation can be done next week, whether it is a gallbladder removal, a hernia repair, a knee replacement or a cataract. Before you have even processed the news, someone hands you a slip with a long list: CBC, blood group, PT/INR, RBS, creatinine, HIV, HBsAg, HCV, ECG, chest X-ray, and an appointment for the "PAC". Many families in India end up paying ₹3,000 to ₹8,000 for these tests without understanding why each one is needed, and then panic when one value is flagged in red.
Pre-operative tests, ordered alongside a pre-anaesthesia check-up (PAC), exist for one purpose: to make anaesthesia and surgery safe for you. Yet Indian hospital audits show that a large share of routine pre-operative tests are not actually needed. One South Indian audit found that about 52% of pre-operative tests were unindicated, and another found that unindicated tests made up over 90% of the extra testing cost. In 2022, the Indian Society of Anaesthesiologists (ISA) released India's first national recommendations on which tests healthy patients really need. This guide explains what each pre-operative test checks, what the ISA guidelines say, what abnormal results mean, how to prepare, and how to avoid repeating tests unnecessarily.
What Is a Pre-Anaesthesia Check-Up (PAC)?
The PAC is a consultation with an anaesthesiologist, usually a few days to two weeks before planned surgery. It is the single most important step in pre-operative assessment, more important than any blood test. During the PAC, the anaesthetist will:
- Take a detailed history: diabetes, blood pressure, heart disease, asthma, thyroid problems, previous surgeries and any reactions to anaesthesia
- Ask about snoring and sleep apnoea, smoking, alcohol and tobacco chewing
- Review all medicines, including Ayurvedic, homeopathic and herbal supplements
- Examine your heart, lungs, airway (mouth opening, neck movement, loose teeth) and spine (if spinal anaesthesia is planned)
- Review your test reports and order further tests if needed
- Assign an ASA physical status grade
- Explain the type of anaesthesia (general, spinal, regional or local with sedation) and the fasting instructions
The ASA grade
| ASA grade | Description | Example |
|---|---|---|
| ASA I | Healthy person | Fit 30-year-old, non-smoker |
| ASA II | Mild, well-controlled disease | Controlled BP or diabetes, mild asthma, smoker, BMI 30-40 |
| ASA III | Severe disease limiting activity | Poorly controlled diabetes, dialysis, past heart attack, BMI over 40 |
| ASA IV | Severe disease that is a constant threat to life | Recent heart attack, severe heart failure |
| ASA V | Not expected to survive without surgery | Ruptured aortic aneurysm |
The ASA grade, together with the grade of surgery (minor, such as removing a skin lump; intermediate, such as hernia repair or knee arthroscopy; major, such as hysterectomy, joint replacement or bowel surgery), decides which tests you actually need.
Common Pre-Operative Tests and Why They Are Done
Blood tests
| Test | What it checks | Why it matters for surgery |
|---|---|---|
| Complete blood count (CBC) | Haemoglobin, white cells, platelets | Detects anaemia (blood loss is harder to tolerate), infection and low platelets (bleeding risk). See our CBC guide. |
| Blood group and Rh | ABO and Rh type | Needed if a blood transfusion may be required; cross-matching follows for major surgery. See our blood group guide. |
| PT/INR and aPTT | Clotting time | Identifies bleeding risk in people on blood thinners or with liver disease. See our PT/INR guide. |
| Blood sugar (FBS/RBS) and HbA1c | Glucose control | Uncontrolled diabetes raises infection and wound-healing problems. |
| Serum creatinine and urea | Kidney function | Guides drug doses, fluids and contrast use. See our KFT guide. |
| Electrolytes (sodium, potassium) | Salt balance | Low or high potassium can cause heart rhythm problems under anaesthesia. |
| Liver function tests (LFT) | Liver health | Liver disease affects clotting and how anaesthetic drugs are cleared. |
| Viral markers: HIV, HBsAg, anti-HCV | Blood-borne infections | Protects theatre staff and guides precautions; HIV testing requires your informed consent. |
| Thyroid (TSH) | Thyroid function | Ordered if you have thyroid disease or symptoms. |
| Urine routine | Infection, sugar, protein | Especially before urological or joint replacement surgery. |
| Urine pregnancy test | Pregnancy | For women of reproductive age, as anaesthesia and some drugs can harm a pregnancy. |
Heart and lung tests
| Test | What it checks | Usually needed when |
|---|---|---|
| ECG | Heart rhythm, old heart damage | Age 45+, heart disease, diabetes, hypertension, major surgery |
| Chest X-ray | Lungs, heart size | Age 50+ for intermediate or major surgery, lung disease, recent chest infection, smokers with symptoms |
| 2D Echo | Heart pumping and valves | Breathlessness, murmur, known heart disease, heart failure. See our ECG, Echo and TMT guide. |
| Pulmonary function test (PFT) | Lung capacity | Asthma, COPD, lung surgery. See our spirometry guide. |
Cost of pre-operative tests in India
A basic pre-operative blood panel at private labs typically costs ₹1,000 to ₹2,500, and extended panels with coagulation, thyroid and viral markers range from ₹2,500 to ₹4,000. An ECG costs ₹200-₹500, a chest X-ray ₹300-₹800 and a 2D Echo ₹1,500-₹3,500. Tests are usually free or very low cost in government hospitals and are included in many PM-JAY surgical packages (see our Ayushman Bharat guide). Pre-operative tests done during a hospital admission are generally covered by health insurance; tests done 30 days before admission are often covered as pre-hospitalisation expenses, but check your policy.
What the ISA 2022 Guidelines Say About Routine Tests
The ISA guidelines, published in the Indian Journal of Anaesthesia (2022), apply to healthy or mildly ill adults (ASA I and II) having planned (elective) surgery. They are not meant to replace the anaesthetist's judgement, and patients with significant illness will need more tests.
| Test | Minor surgery | Intermediate surgery | Major surgery |
|---|---|---|---|
| CBC (haemoglobin) | Suggested | Suggested | Suggested |
| Serum creatinine | Not suggested | Suggested | Suggested |
| Electrolytes | Not suggested | Not suggested | Not suggested |
| Liver function tests | Not suggested | Not suggested | Suggested |
| PT/INR, aPTT | Not suggested | Not suggested | Not suggested |
| Blood sugar (non-diabetics) | Not suggested | Not suggested | Not suggested |
| ECG | If age 45+ | If age 45+ | Suggested for all |
| Chest X-ray | Not suggested | If age 50+ | If age 50+ |
Validity of old reports
One of the most practical parts of the ISA guidance is how long normal results remain valid, provided your health has not changed:
- Normal CBC, kidney function, LFT and coagulation tests: 2 months
- Normal ECG and chest X-ray: 12 months
So if you had a normal CBC and creatinine at your annual check-up six weeks ago, those results may not need repeating. The catch is that you must be able to produce the report at the PAC. This is exactly where having your reports organised in MedicalVault helps: you can pull up last month's CBC or last year's ECG on your phone in seconds instead of searching through files at home. Hospitals may still have their own policies, so ask politely rather than refuse.
Why do hospitals still order so many tests?
Reasons include institutional protocols, fear of legal liability, insurance requirements, and the simple fact that a single standard panel is easier to manage than individualised orders. Viral markers are also commonly done for every surgical patient in India as an infection-control policy. It is reasonable to ask your surgeon or anaesthetist, "Which of these tests are needed for me, and can my recent reports be used?"
Understanding Abnormal Pre-Operative Results
An abnormal value does not automatically cancel surgery. Your anaesthetist weighs it against the urgency and type of operation. Common scenarios:
Low haemoglobin (anaemia)
Anaemia is extremely common in India; NFHS-5 found that 57% of women and 25% of men aged 15-49 are anaemic. Before major planned surgery with expected blood loss, doctors usually want haemoglobin corrected, often aiming for 10-12 g/dL or above depending on the case. Iron tablets take several weeks; intravenous iron (such as ferric carboxymaltose) works faster. Read our iron deficiency anaemia guide.
High blood sugar or HbA1c
Uncontrolled diabetes increases the risk of wound infection and poor healing. Many anaesthetists prefer an HbA1c below about 8.5% before elective major surgery and may postpone surgery so sugars can be brought under control. Emergency surgery goes ahead with insulin to control sugar during the operation. See our HbA1c guide.
Raised creatinine
Kidney impairment changes medicine and fluid choices and increases risks from contrast dyes and certain painkillers (NSAIDs such as diclofenac and ibuprofen). It may trigger further tests or a nephrologist's opinion.
Prolonged INR or low platelets
An INR above about 1.5 or a platelet count below 50,000-1,00,000 per microlitre (depending on the surgery and anaesthesia type) increases bleeding risk. Spinal and epidural anaesthesia have stricter thresholds. Causes include blood thinners, liver disease and conditions like dengue; see our low platelet guide.
Abnormal ECG
Changes such as an old heart attack pattern, atrial fibrillation or a heart block may lead to a 2D Echo or cardiologist review. Many minor ECG variations are harmless and do not delay surgery.
Positive viral marker
A positive HBsAg, HCV or HIV test does not mean surgery will be refused. It means the team will take standard extra precautions, and you will be referred for proper evaluation and treatment of the infection. Your result is confidential.
How to Prepare for Surgery: Medicines, Fasting and Documents
Medicines: tell the anaesthetist everything
Never stop or change any medicine on your own, but expect the anaesthetist to give instructions about these common ones:
| Medicine | Common Indian brands | Usual advice (confirm with your doctor) |
|---|---|---|
| Aspirin | Ecosprin, Disprin | Often continued for heart patients; sometimes stopped 5-7 days before |
| Clopidogrel, ticagrelor, prasugrel | Clopilet, Deplatt, Brilinta | Often stopped 5-7 days before; never stop after a recent stent without the cardiologist's approval |
| Warfarin, acenocoumarol | Warf, Acitrom | Usually stopped about 5 days before with INR check; bridging may be needed |
| Newer blood thinners (apixaban, rivaroxaban, dabigatran) | Eliquis, Xarelto, Pradaxa | Stopped 1-3 days or more before, depending on kidney function |
| SGLT2 inhibitors | Forxiga, Jardiance, Gibtulio | Usually stopped 3 days before (risk of ketoacidosis) |
| Metformin | Glycomet, Glyciphage | Often skipped on the day of surgery |
| Insulin and sulfonylureas | Various | Doses adjusted the night before and on the morning of surgery to avoid low sugar |
| GLP-1 medicines | Ozempic, Rybelsus, Mounjaro | May need to be withheld because they slow stomach emptying |
| BP medicines (ACE inhibitors, ARBs) | Telma, Losar, Envas | May be withheld on the morning of surgery |
| Herbal supplements (ginkgo, garlic, fish oil, high-dose vitamin E) | Various | Often stopped 1-2 weeks before (bleeding risk) |
People with diabetes need special care around fasting to avoid low sugar on the day of surgery; our low blood sugar guide explains the warning signs.
Fasting before anaesthesia
Standard guidance for adults having planned surgery (your hospital's instructions take priority):
- Solid food, milk and tea with milk: stop 6 hours before
- Heavy, fried or fatty meals: stop 8 hours before
- Clear fluids (water, clear apple juice, black tea without milk): allowed up to 2 hours before
- Take approved morning medicines with a small sip of water
Do not chew gum, paan or tobacco on the morning of surgery. Stopping smoking even a few weeks before surgery improves lung and wound healing.
What to bring to the PAC and admission
- All recent test reports, ECG and X-ray images or reports
- Previous discharge summaries and operation notes (see our discharge summary guide)
- A complete list of current medicines with doses
- Details of any allergies or reactions to anaesthesia in you or a blood relative
- Insurance card, policy details and ID proof
Keeping all of this in one place in MedicalVault means nothing gets left behind, and with family sharing, the relative accompanying you to the hospital can access the same reports.
Key Takeaways
- The pre-anaesthesia check-up (PAC) matters more than any single test; be completely honest about illnesses, medicines and habits.
- Tests should match your health and the type of surgery. For healthy adults, the ISA 2022 guidelines suggest a CBC for everyone, creatinine for intermediate and major surgery, ECG above age 45 and chest X-ray above age 50 for bigger operations.
- Normal blood tests stay valid for about 2 months and a normal ECG or chest X-ray for about 12 months if your health has not changed, so carry recent reports.
- Abnormal results rarely cancel surgery outright; they help the team prepare, for example by correcting anaemia or controlling sugar first.
- Blood thinners, diabetes medicines, SGLT2 inhibitors, GLP-1 medicines and herbal supplements often need adjustment; follow only your doctor's instructions.
- Follow fasting rules exactly: usually 6 hours for food and 2 hours for clear fluids.
- Keep your reports, discharge summaries and medicine list organised in MedicalVault so you can share them instantly at the PAC and avoid paying for repeat tests. Visit our features page to see how it works.