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Surgical risk is a way of evaluating the clinical status and he alth conditions of the person who will undergo surgery, so that risks of complications are identified throughout the period before, during and after surgery.
It is calculated through the physician's clinical assessment and the request for some tests, but, to facilitate, there are also some protocols that better guide medical reasoning, such as the ASA, Lee and ACP, for example.
Any physician can perform this evaluation, but it is usually performed by the general practitioner, cardiologist or anesthetist. In this way, it is possible that some particular care is taken for each person before the procedure, such as requesting more appropriate tests or performing treatments to reduce the risk.
How is the preoperative assessment performed
Medical evaluation performed before surgery is very important to better define what type of surgery each person can or cannot have, and determine whether the risks outweigh the benefits. The evaluation involves:
1. Conducting the clinical examination
The clinical examination is performed by collecting data from the person, such as medications in use, symptoms, diseases they have, in addition to physical assessment, such as cardiac and pulmonary auscultation.
From the clinical evaluation, it is possible to obtain the first form of risk classification, created by the American Society of Anesthesiologists, known as ASA:
- ASA 1: he althy person, without systemic diseases, infections or fever;
- ASA 2: person with mild systemic disease, such as controlled high blood pressure, controlled diabetes, obesity, age over 80 years;
- ASA 3: person with severe but not disabling systemic disease, such as compensated heart failure, infarction more than 6 months ago, cardiac angina, arrhythmia, cirrhosis, diabetes, or hypertension decompensated;
- ASA 4: person with life-threatening disabling systemic disease, such as severe heart failure, infarction less than 6 months ago, lung, liver, and kidney failure;
- ASA 5: terminally ill person, not expected to survive more than 24 hours, such as after an accident;
- ASA 6: person with detected brain death, who will undergo organ donation surgery.
The higher the ASA classification number, the greater the risk of mortality and complications from the surgery, and one should carefully assess which type of surgery may be worthwhile and beneficial for the person.
2. Assessment of the type of surgery
Understanding the type of surgical procedure that will be performed is also very important, because the more complex and time-consuming the surgery, the greater the risks that the person may suffer and the care that must be taken.
Thus, the types of surgery can be classified, according to the risk of cardiac complications, such as:
|Low risk||Intermediate Risk||High Risk|
|Endoscopic procedures such as endoscopy, colonoscopy;
Superficial surgery, such as skin, breast, eyes.
|Surgery of the chest, abdomen or prostate;
Head or neck surgery;
Orthopedic surgery, such as after fracture;
Correction of abdominal aortic aneurysms or removal of carotid thrombus.
|Emergency major surgery.
Surgeries of large blood vessels, such as aorta or carotid artery, for example.
3. Cardiac risk assessment
There are some algorithms that more practically measure the risk of complications and death in non-cardiac surgery, by investigating the person's clinical situation and some tests.
Some examples of algorithms used are the Goldman Heart Risk Index, Lee's Revised Heart Risk Index and theAmerican College of Cardiology (ACP) Algorithm, for example. To calculate the risk, they consider some data of the person, such as:
- Age, which is more at risk over 70 years;
- Myocardial infarction history;
- History of chest pain or angina;
- Presence of arrhythmia or vessel narrowing;
- Low blood oxygenation;
- Presence of diabetes;
- Presence of heart failure;
- Presence of lung edema;
- Type of surgery.
From the data obtained, it is possible to determine the surgical risk. Thus, if it is low, it is possible to release the surgery, and if the surgical risk is medium to high, the doctor can give guidelines, adjust the type of surgery or request more tests that help to better assess the person's surgical risk.
4. Performing necessary exams
Preoperative exams should be performed with the aim of investigating any alteration, if there is a suspicion, which could lead to a surgical complication. Therefore, the same tests should not be ordered for all people, as there is no evidence that this helps to reduce complications. For example, in people without symptoms, with low surgical risk and who will undergo low-risk surgery, it is not necessary to perform tests.
However, some of the most commonly requested and recommended exams are:
- Hemogram: people undergoing intermediate or high-risk surgery, with a history of anemia, with current suspicion or with diseases that can cause changes in blood cells;
- Coagulation tests: people using anticoagulants, liver failure, history of bleeding disorders, intermediate or high risk surgeries;
- Creatinine dosage: patients with kidney disease, diabetes, high blood pressure, liver disease, heart failure;
- Chest X-ray: people with conditions such as emphysema, heart disease, age over 60, people at high cardiac risk, with multiple diseases or who will undergo chest surgery or abdomen;
- Electrocardiogram: people with suspected cardiovascular disease, history of chest pain and diabetics.
Generally, these exams are valid for 12 months, without the need to repeat this period, however, in some cases, the doctor may find it necessary to repeat before. In addition, some physicians may also consider it important to order these tests even for people without suspected alterations.
Other tests, such as a stress test, echocardiogram or holter, for example, may be requested for some types of more complex surgery or for people with suspected heart disease.
5. Making preoperative adjustments
After the tests and exams have been carried out, the doctor can schedule the surgery, if all is well, or he can give guidelines so that the risk of complications in the surgery is reduced as much as possible.
Thus, he may recommend doing other more specific tests, adjusting the dose or introducing some medication, evaluating the need for correction of heart function, through heart surgery, for example, guiding some physical activity, loss of weight or stop smoking, among others.