1. PREOPERATIVE ASSESSMENT

Every patient should be seen by the anaesthetist before surgery. The anaesthetist must determine if the patient is ill, if the illness increases the chance that the surgery/anaesthesia may adversely affect the patient’s health and if the illness can be improved before surgery.

The anaesthetist should also ask about the past medical history, past anaesthetic history, family history, examine the patient and assess the patient’s airway. With this knowledge the anaesthetist can decide if the patient needs medical treatment before the surgery, when the surgery can be done, what sort of anaesthetic to give and how to look after the patient after surgery.

Medical History

The anaesthetist must take a medical history. This history includes why the patient is having the surgery and also any serious illness, in particular heart disease (including ischaemic heart disease, cardiac failure and valvular disease), respiratory disease (including asthma and smoking), diabetes, kidney disease and reflux oesophagitis. The anaesthetist should also ask about medications, allergies and determine the patient’s exercise tolerance.

The patient’s exercise tolerance gives a good indication of the chance that the patient’s health will be poorly affected by surgery/anaesthesia. If the patient is unable to climb a flight of stairs then they are at increased risk.

Medications

Drugs of special significance to anaesthesia include anticoagulants, steroids and diabetic treatment. As a general rule, with the exception of these drugs, it is best not to stop any drugs before surgery.

Allergy and Drug Reactions

The anaesthetist must ask the patient about unusual, unexpected or unpleasant reactions to drugs. True allergic reactions are uncommon but any drug that has caused a skin reaction, facial or oral swelling, shortness of breath, choking, wheezing or hypotension should be considered to have caused an allergic response and must be avoided.

Anaesthetic History

The anaesthetist should read any old anaesthetic notes. Good anaesthetic notes will include responses to drugs, ease of mask ventilation and endotracheal intubation and any anaesthetic complications. Patients should be asked about their prior anaesthetics.

Family History

The anaesthetist should ask if anyone in the family has had a bad reaction to anaesthesia.

Smoking and Alcohol

Patients should be encouraged to stop smoking and alcohol before surgery.

Physical Examination

The anaesthetist must perform a physical examination. This examination must pay special attention to the patient’s airway, cardiovascular and respiratory systems.

Every patient’s airway must be assessed to determine how difficult it will be to mask ventilate and intubate. This assessment includes measuring mouth opening, neck flexion and extension and the distance from the mandible to the thyroid cartilage and looking in the mouth.

Cardiovascular examination is particularly concerned with determining the hydration status of the patient (heart rate, blood pressure, postural drop, any signs of dehydration), signs of cardiac failure and cardiac valve abnormalities. Patients who have a low blood pressure and tachycardia must have intravenous fluid resuscitation before commencing surgery/anaesthesia.

Respiratory examination should look for signs of upper airway obstruction, bronchospasm or infection.

At this stage the anaesthetist may have diagnosed several problems that require further investigation and treatment before surgery.

Documentation

The preoperative assessment should be documented, ideally on a preoperative assessment form.

ASA classification

It is useful to assign an ASA (American Society of Anesthesiologists) classification.

ASA 1: a normal healthy person

ASA 2: a patient with mild systemic disease

ASA 3: a patient with severe systemic disease limiting activity but not incapacitating

ASA 4: a patient with incapacitating systemic disease that is a constant threat to life

ASA 5: an extremely ill patient who is not expected to live 24 hours with or without an operation

Recommendation

 The anaesthetist must decide: 

 If the patient’s condition can be improved by further treatment.

 How urgent the surgery is.

 If surgery can be delayed until the patient is in the best possible condition.

 What the best anaesthetic technique for the patient and planned surgery is.

 How to care for the patient after surgery (especially pain control).

Finally, the anaesthetist must discuss the anaesthetic with the patient and answer any questions.