1.4: pre-operative preparation (elective and emergency): 

Any medical condition that can be corrected or improved must first be treated so that the patient is in the fittest possible physical state before surgery. The following are some medical problems that may require treatment. 

Anemia: Depending on the time available must always be investigated before treatment and condition corrected before anesthesia and surgery. 

Cardiovascular disease 

• Myocardial infarction: A minimum of three months and preferably six months must be allowed before elective surgery. 
• Cardiac failure must be treated before elective surgery. 
• Arrhythmias: Arrhythmia has to be worked up on their origin (supra ventricular, ventricular, atrial fibrillation..), severity, their effect on the blood pressure or cardiac output. For elective surgery an attempt must be made to involve respective specialty and correct the arrhythmia to the best possible degree. 
• Hypertension: This must be treated pre-operatively. Uncontrolled hypertension can result in left ventricular failure, arrhythmias and cerebrovascular disturbances under anesthesia. 

Respiratory disease 

• Acute respiratory disease is a contraindication for elective surgery and anesthesia. 
• Chronic respiratory disease e.g. COPD (Chronic Obstructive Respiratory Disease) must first be investigated and then treated by the respective discipline and measures of physiotherapy, no smoking, bronchodilators and antibiotics if necessary. 
• Asthma must be treated with the appropriate bronchodilators until the chest is clear for auscultation, before elective surgery is contemplated. 

Metabolic diseases 

• Diabetes mellitus must be first investigated and assessed and then controlled before elective surgery is performed. The anesthetist must very carefully work out a regime for the control of the diabetic state during the operative period. 
• Liver disease especially in relation to the Prothrombin index. After a severe case of infective hepatitis, elective operation is best postponed for a minimum of six months. 
• Thyroid disorders: Both hyperthyroidism and hypothyroidism must be corrected before elective surgery. 

Fluid Imbalance: Fluid and electrolyte imbalance will be more common in patients for emergency surgery. Whenever possible the volume of circulating fluid should be corrected before anesthesia. Fluid loss may result from a variety of causes, including blood loss, burns, vomiting, diarrhea, loss through fistulae, loss into the gut (ileus), deficient intake, excessive loss through the skin (especially in the extremes of age) and excessive urinary loss. 

Briefly, the following symptoms and signs suggest dehydration: 

• Thirst  
• Dry mouth 
• Diminished skin turgor 
• Rapid pulse 
• Decreased urine output 
• In the later stages a fall in blood pressure 
• A high BUN and a raised specific gravity of urine confirm the diagnosis 

The appropriate fluid must be administered with a close watch on these parameters. 

Electrolyte imbalance: Sodium and potassium imbalance especially must be corrected pre-operatively. A low potassium level can result in hypotension, arrhythmias and cardiac arrest. It can also result in skeletal and smooth muscle weakness and interfere with the action of relaxant drugs. A high potassium level is also associated with cardiac arrhythmias. 

Smoking: This increases intra and post-operative morbidity due to associated bronchial exudation and bronchospasm. It should ideally discontinue for more than 6weeks pre-operatively. However, cessation for even 24 hours pre-operatively reduces the morbidity. 

Special problems related to emergency surgery: In addition to the problems already listed, patients presenting for emergency surgery pose the problems of: 

• Full stomach. 
• Hypovolemia due to blood or fluid loss. 

The unfasted patient (full stomach) 

The dangers of vomiting or regurgitation under anesthesia are discussed elsewhere. In considering the pre-operative measures we can take to prevent this complication: 

Before the patient leaves the ward a senior nurse should: 

• Check the identity of the patient 
• Check the site and side of the operation 
• Ensure the consent form is signed in accordance with the rules of the hospital 
• It is good to weigh every patient At least every child under the age of 12 must be weighed to allow calculation of drug dosages 
• Grossly underweight and overweight adults must also be weighed 
• Ensure that fasting rules have been observed 
• Remove lipstick, nail varnish, etc. 
• Remove dentures, artificial limbs and artificial eyes 
• Empty bladder 
• Dress the patient in a linen gown with an identification label 
• Give premedication if any ( premedications will be discussed in session 8 at the end of this module) 

Fasting guidelines 

Elective cases 

• Adults: no solid food for 8 hours; clear liquids or water up to 2 hours preoperatively. 
• Children: no solid food for 8 hours; non-human milk up to 6 hours; breast milk up to 4 hours; water up to 2 hours preoperatively. 
• Patients who are at risk of aspiration regardless of period of starvation to consider aspiration risk reduction strategies, such as insertion of N/G tubes, cricoids pressure etc. (DM, pregnancy, trauma, etc) in addition it is better to bring table on page 55 that describes causes of delayed gastric emptying 

Emergency cases: If possible, delay surgery for 8 hours since the last solid food intake; these patients should have a rapid sequence induction for anesthesia. If the surgery cannot be delayed for 8 hours, then still proceed with a rapid sequence induction for anesthesia