Assessment before Anesthesia / Surgery
©G.M. Woerlee, 2017–2023
“Why must I go to a preoperative assessment clinic to see an anesthesiologist? After all, the surgeon has determined I need surgery — all the anesthesiologist has to do is keep me asleep during the operation. So what has the anesthesiologist got to say that is important? … ”
All patients are sent to a preoperative assessment clinic / anesthesiologist after a surgeon determines the requirement for an operation. Yet some patients wonder why they must attend such a clinic, yet the reality is rather different to what is implied by this regularly heard complaint.
The work of the anesthesiologist is part of the surgical “Chain of Care”
The anesthesiologist is a medical specialist, and part of a chain of “Chain of Care” before, during, and after the surgical process. This is called by the name “Perioperative Care”, and is described by the following steps.
- The surgeon makes diagnosis of a problem presented by a patient.
- The surgeon determines that this problem can be best treated by surgery, and determines which operation is required.
- The patient goes to the preoperative assessment clinic / anesthesiologist.
- The anesthesiologist takes a medical history and performs a directed physical examination.
- The anesthesiologist assesses the likely effect of the planned operation upon the patient, the effects of anesthesia upon the patient, and most importantly the effects of both occurring together. After all, surgery does not occur without anesthesia, and anesthesia is never administered without surgery.
- Many patients suffer from medical disorders or take medication. These all can affect the way anesthesia plus surgery affect the body.
- If necessary, the anesthesiologist consults with other medical specialists, and arranges for the condition of the patient to be improved / optimized, so that the patient undergoes surgery in the best possible condition.
- Anesthesia is administered and the operation occurs.
- Patients are admitted to the recovery area after operation.
- Once sufficiently recovered, the patient is admitted to a department where optimal postoperative care can be administered.
- Patients are discharged home after sufficiently recovering.
This is the chain of perioperative care, and anesthesiologists are part of the team, functioning within the umbrella of perioperative care. The figure below shows the situation.
What does the anesthesiologist do during preoperative assessment?
One fact — the surgeon does not administer anesthesia — the surgeon concentrates on the work of surgery — the anesthesiologist administers and maintains anesthesia to make the work of the surgeon possible. Anesthesia is not simply “knocking a person out to keep them unmoving during an operation”. The anesthesiologist takes account of the following facts when assessing someone before an operation.
- Anesthesia can be local in the place where the operation occurs, or regional where a whole part of the body is anesthetized. These techniques may be combined with drugs to relax a person or cause them to be sleepy (sedation).
- General anesthesia uses gases or drugs to: cause sleep, prevent unconscious reactions of the body to pain, and to relax the muscles of the area being operated. Modern general anesthesia is usually administered with a combination of three or more drugs to achieve these aims. The anesthesiologist uses his / her knowledge of the effects of these drugs in combination to provide ideal operating conditions for the surgeon, as well as to keep the patient asleep.
- Safe anesthesia, regardless of the type of anesthesia, requires knowledge about the medical conditions of the patient, as well as the type of surgery planned. It is the combination of all these things that determine which anesthesia techniques and drugs are the best, and safest for a particular person.
- Anesthesia can affect the functioning of the heart, circulation, and kidneys. This may cause serious problems in persons with heart and blood vessel diseases, or in those persons who may be severely dehydrated or have lost a lot of blood. The anesthesiologist makes appropriate arrangements to treat these problems before anesthesia and operation, or plans how best to minimize their effects.
- Unconscious persons under anesthesia still respond to the pain of surgery with reflex movements, blood pressure, or heart problems. Pain of surgery can even cause some people to awaken under anesthesia, (actually very similar to shaking, or doing something painful to a normally sleeping person) (see ). The anesthesiologist responds by keeping the person unconscious by administering more sleep-inducing drugs, administering powerful painkilling drugs to prevent unconscious responses to extra painful moments, as well as administering other drugs to relax the muscles to aid the surgeon in his / her work. The condition of the patient or the type of surgery may necessitate other specific drugs or techniques, so the anesthesiologist determines and plans for these things during the preoperative assessment.
- Major surgery, or surgery for injuries can cause losses of significant amounts of blood, and other fluids. This can cause problems with heart, circulation, and kidney function. The surgeon is busy performing surgery, while the anesthesiologist maintains the circulation with fluids, together with blood transfusions as needed, and drugs. The anesthesiologist assesses the likelihood of these problems and makes appropriate arrangements.
- Just as poorly performed surgery, inadequate, or poorly administered anesthesia can result in severe problems after the operation. So the anesthesiologist plans to administer personalized anesthesia where needed.
- The various forms of local, or regional anesthesia, can also cause problems, varying from minor to lethal in some cases. So the anesthesiologist must determine whether local, regional, or general anesthesia is the most appropriate form of anesthesia for the planned operation, the psychological profile of the patient, and the individual surgeon.
- The psychological profile of each individual, the use of tobacco products, alcohol, other recreative drugs, and the medication used by a patient can also determine the nature of any preparation prior to operation, as well as the type of anesthesia, and the location for postoperative management (ward, intensive care, ambulatory care).
- Some people have chronic diseases resulting in severe problems with some types, or techniques of anesthesia, and when this is also combined with the reactions of the body to the pain of surgery, serious problems with heart, circulation, or lung function may occur. The anesthesiologist assesses the likelihood of these problems, and makes arrangements to prevent these problems, or measures to lower the chance of their occurrence.
These are but SOME of the considerations made by the anesthesiologist during the preoperative assessment. Preoperative assessment is an important aspect of preparation for anesthesia and surgery, because the anesthesiologist is not just assessing the safety of anesthesia, but is actually assessing the combined risk of anesthesia PLUS the planned surgery! More aspects of these problems are discussed in detail in the homepage of the perioperative decision-support software called PANSURAS (Perioperative ANesthesia & SURgical Assessment System)