Preoperative tests

    Last updated date: 28-Jan-2023

    Originally Written in English

    Preoperative tests

    Preoperative tests


    Your surgeon will want to ensure that you are physically and mentally prepared for surgery. Before surgery, you will undergo several exams and testing. Before your operation, several different people on your surgical team may ask you the same questions. This is because your team needs to gather as much information as possible in order to provide you with the finest surgical outcomes possible.


    What is a preoperative test?

    preoperative test

    Pre-op refers to the time preceding surgery. It translates as "before operation." You will meet with one of your physicians during this time. This might be your surgeon or primary care doctor; this exam is normally required one month before surgery to provide your physician's time to handle any medical concerns you may have prior to surgery. During this session, you will be asked about your health history. This is referred to as "taking your medical history." Your doctor will also do a physical examination. If you go to your primary care doctor for a pre-op checkup, be sure your hospital or surgeon receives the results.Some hospitals may additionally need you to call or meet with an anesthetic pre-op nurse prior to surgery to discuss your health. You should also consult with your anesthesiologist a week before surgery. This doctor will provide medication that will put you to sleep and prevent you from feeling pain during the operation.

    A preoperative ('pre-op') evaluation will be performed before surgery. This is often performed at a preoperative evaluation clinic, either at the hospital or in your neighborhood. You will be asked questions about your health and any medications you are taking during this consultation. You may then be asked to take certain exams. These are known as 'preoperative testing.'


    Why are preoperative tests performed?

    preoperative tests performed

    Preoperative tests advise your nurse or doctor about: 

    • If you will require special care before, during, or after surgery
    • The possibility of anything going wrong, so that they may discuss these concerns with you.

    The tests you will require are mostly determined by:

    • Your physical and mental well-being
    • The sort of anesthesia and operation you'll be undergoing.

    If you have testing at your doctor's office, the findings must be included in the letter. Several professionals may be engaged in your preoperative evaluation. You will most likely be seen by a nurse and, if necessary, an aesthetic or a doctor who specializes in surgical treatment. Your doctor will also be consulted. When you are referred to a surgeon, notify your primary care physician. Consult your primary care physician or a practice nurse about this.


    Why are preoperative tests necessary?

    A pre-op exam does more than just clear a patient for surgery. It is a method of gathering as much information on the patient's health as feasible. The information gathered will be utilized to identify potential sources of hazards and consequences. This will assist the surgeon, anesthesiologist, and other medical personnel involved in the operation and recovery in better preparing for potential hazards and, if required, making modifications to reduce those risks. Pre-operative screening also enables the medical team to develop a more thorough and accurate post-operative recovery care plan. Overall, doctors require patients to have a pre-op screening in order to avoid serious and unexpected consequences during or after surgery. A pre-op test is used to confirm that patients do not have any underlying health issues that might affect the result of the operation.

    What about preoperative tests?

    preoperative tests

    Preoperative tests are a series of examinations performed before undergoing a scheduled (or 'elective') procedure. These tests may be performed even if you appear to be in good health in order to offer information about issues that may alter the therapy you require.

    The tests you undergo before your surgery will be dictated by your age, general health, any illnesses you have or medications you are taking, and the type of surgery you will have.

    The following are some examples of tests you could provide.

    • Full blood count: A blood sample is collected to count the various kinds of blood cells. This is a measurement of hemoglobin and the number of different types of blood cells. This is a measurement of hemoglobin and the number of different types of blood cells. This can detect diseases like anemia or thrombocytopenia, which may necessitate extra care to limit your risk of bleeding during surgery.
    • Blood clotting tests: These tests are performed to determine whether or not your blood clots normally and how long it takes to clot. They may be performed if you are on blood-thinning medications such as warfarin, are undergoing renal dialysis, or have liver or blood vessel (vascular) illness.
    • Blood gasses: This test determines the concentrations of oxygen and carbon dioxide in the blood. If you have lung or heart issues, this may be done before your surgery.
    • Blood glucose: Before undergoing any major surgery, this test can be done to determine if you have diabetes. Diabetes can have an impact on surgical recovery, therefore it's vital to be aware of this ahead of time so that any required measures can be taken.
    • Urine dipstick test: This test is used to identify specific compounds in the urine that may suggest illness, such as glucose in the urine. It can also tell you how well your kidneys are operating and detect urinary tract infections.
    • Kidney function tests: These entail a number of tests on both blood and urine samples to establish how well your kidneys are operating, and are often performed prior to any major surgery.
    • Sickle cell test: Sickle cell anemia is a hereditary condition that reduces the capacity of hemoglobin in red blood cells to transport oxygen. If you inherit the sickle cell gene from both parents, you will get sickle cell anemia, which can be fatal. If you receive the sickle cell gene from only one parent, you will have 'sickle cell trait,' which produces no symptoms but indicates that you are a 'carrier' of the sickle cell gene. If you have sickle cell anemia or sickle cell trait, having a general anesthesia may create complications; consequently, if you are of an ethnic origin that is thought to be at risk of sickle cell illness, you should undergo this test before having an operation.
    • Pregnancy test: If you suspect you are pregnant, this test should be taken before any surgery, as anesthetic and surgery might harm your unborn child.
    • Lung function tests: Lung function tests are used to determine how effectively you breathe and may be performed prior to surgery if you have any sort of lung illness, such as asthma or bronchitis.
    • Chest X-ray: If you are an older person (over 60) with lung or heart illness who is having major surgery, a chest X-ray may be obtained before the procedure.
    • Electrocardiogram (ECG): This test is used to detect cardiac abnormalities such as abnormal heart rhythms. It may be performed prior to surgery if you are an older individual (over 60) with chest discomfort or a history of heart disease and are having major surgery. 
    • Echocardiogram (echo): Most individuals will not require an echocardiogram (echo) before surgery, but you may be offered one if you have a heart condition, such as a heart murmur, or symptoms of a heart disease, such as chest discomfort or shortness of breath. Before evaluating if an echo is necessary, your doctor should do an ECG.
    • MRSA testing: MRSA is a kind of bacterium that is resistant to antibiotics (glossary). The bacterium may dwell in many people's skins without causing any harm, but once inside the body, it causes illness, especially in those who are ill. This test is used to determine whether or not this bacterium is present in your body. If you require hospitalization for planned or emergency care, or if you have previously had MRSA colonization or infection and require admission to a high-risk ward, you will most likely be examined for MRSA ( e.g., surgery, trauma, dialysis, intensive care and cancer). If you are not staying overnight, you are not usually checked. Screening is often performed before hospital admission, in a pre-admission clinic, GP practice, or outpatient clinic. Swabs (similar to cotton bud) are taken from various parts of the body for the test (e.g., nose, groin, armpit, wound, catheter sites or damaged skin). You are MRSA positive if the MRSA bacterium is discovered in any region of your body. A body wash may be suggested to remove the MRSA germs from your body. Additional throat gargles wound ointments, or antibiotics may be necessary at times. A minimum of three cycles of therapy are provided, and you will be tested again following the treatment. When you are free of MRSA germs, you are classified as MRSA-negative. Intravenous antibiotics may be provided around the time of operation to reduce the chance of the infection spreading further. 


    When would preoperative tests be required?

    preoperative tests be required

    People undergoing specific types of surgery or who have long-term health issues may require preoperative testing.

    Pre-intermediate surgery tests

    Intermediate surgeries include varicose vein removal, tonsil removal, and knee arthroscopy (where a surgeon uses keyhole surgery to look inside the knee).

    • Diabetes, heart disease, or kidney disease: renal function, complete blood count, and electrocardiogram
    • Lung cancer: Lung function, blood gas, renal function, and ECG tests
    • Cirrhosis of the liver: Test for blood clotting

    Examinations prior to major surgery

    Major surgery might involve removing a woman's womb (hysterectomy), removing part or all of the colon (large bowel), or replacing a joint like the hip or knee. If you are having significant surgery, you are more likely to require testing. Everyone undergoing major surgery should be given a complete blood count. 

    You will almost certainly be offered:

    • kidney function testing
    •  ECG.
    •  If you have lung disease, you may be offered lung function testing.
    • If you have chronic liver illness, you may need blood clotting testing.


    When preoperative tests are not helpful?

    Preoperative tests

    If you're having surgery, you could undergo blood and urine testing first. If you have specific health issues or disorders, these tests may be beneficial. For example, if you have a blood-clotting disorder, a test can determine whether you are at risk of excessive bleeding after surgery. However, most healthy people do not require the testing, especially before minor surgery. This is why:

    For low-risk surgery, the tests are frequently ineffective.

    Before surgery, many healthy people get standard lab testing. Test results seldom affect their surgeon's choice to operate or make surgery safer in these circumstances. The tests are especially unneeded before low-risk surgery, such as eye surgery, hernia surgery, or skin surgery, or a breast biopsy. 


    Other Doctors' Visits

    Doctors' Visits

    Your surgeon will want to ensure that any other medical disorders you may have do not create complications during your operation.

    As a result, you may need to go to:

    • If you have a history of cardiac issues, smoke heavily, have high blood pressure or diabetes, or are out of shape and can't walk up a flight of stairs, you should see a cardiologist.
    • If you have diabetes or if your blood sugar level was high at your pre-op appointment, you should see a diabetic doctor (endocrinologist).
    • If you have obstructive sleep apnea, which causes choking or a pause in breathing while sleeping, consult a sleep doctor.
    • If you've experienced blood clots in the past or have close relatives who have, you should see a specialist who specializes in blood diseases (hematologist).
    • Before surgery, see your primary care physician for a review of your health issues, an exam, and any necessary testing.


    What are the risks?

    Risks of preoperative test

    The lab tests may lead to additional testing. Although blood and urine tests are quite safe, they can trigger false alarms. This might result in worry and more examinations. It might also cause your procedure to be postponed unnecessarily. For example, one test may be followed by another, an ultrasound, a biopsy, or a radiation-exposure test, such as an X-ray or CT scan.

    When is lab testing recommended?

    If you have specific health issues or diseases, or if your medical history indicates a need, the tests may provide useful information to your health care physician. For example:

    • If you bruise easily, take blood thinners, had bleeding issues during a previous surgery or dental operation, if you have a family history of bleeding issues, you may require a blood test to determine whether your blood clots normally.
    • If you have an illness, such as diabetes, you will almost certainly require a test to ensure that it is under control.
    • A pregnancy test may be required for women of reproductive age.
    • The examinations may also be required before a major procedure such as heart, lung, or brain surgery.

    Your health care provider may monitor your condition more closely during or after surgery based on the test results. You may need to postpone surgery until an issue is resolved. Alternatively, your doctor may alter the treatments and anesthetic.



    Routine preoperative tests for surgery attempt to decrease needless testing by counseling patients on which tests to provide them before small, intermediate, and major or complicated surgery, while taking unique comorbidities into consideration (cardiovascular, renal, and respiratory conditions and diabetes and obesity). It does not cover pregnant women or those undergoing cardiothoracic or neurosurgical operations.