PRE-OPERATIVE EVALUATION

A patient for elective surgery needs thorough evaluation not only for suitability of general anaesthesia but also for possible complications related to the operation (e.g. a toxic goitre) or that may affect the outcome of the operation (e.g. a chronic cough in a hernia patient).

History

i) A thorough history must be taken (this should include a history of chronic illnesses, a drug history and history of previous surgical encounters).

Examination

i) A thorough physical examination and in particular check for:

- anaemia

- jaundice

- level of hydration

- fever

- lymph node enlargement.

Vital signs must be taken and recorded. For any major operation a check chart need be kept for at least 24 hours before surgery.

Specific charts are available for certain disease conditions e.g. diabetes, hypertension, asthma etc.

Investigations

A set of basic investigations is necessary:

• Urinalysis

• Haemogram (Hb, WBC, PCV)

• Urea and electrolytes

• A chest X-ray is useful in some cases.

To this may be added any investigation relevant to the diseased system:

• Urine for C&S

• An intravenous urography in most urological operations

• Liver function tests and prothrombin time index (PTI) in hepatobiliary disease

• Creatinine clearance in renal patients

• Electrocardiogram (ECG) in hypertensive, and known heart patients

• A thyroid profile may be necessary before thyroid surgery.

Management - Supportive before surgery

Correction of conditions that are identified in the evaluation is necessary and critical:

• Correction of volume and electrolyte imbalance

• Control of blood pressure

• Control of thyrotoxicosis

• Control of diabetes mellitus (and any other metabolic disease)

• Correction of anaemia and malnutrition

• Prophylactic antibiotics where indicated [see appropriate section for details].

USE OF BLOOD TRANSFUSION IN SURGERY

• Avoid “topping-up” anaemic patients prior to surgery

• Use blood intra-operatively for Hb <8.0 g/dl AND blood loss of 10% of blood volume or more

• Autologous transfusion is frequently used in patients for elective surgery. A pint of blood is removed every 7 days prior to surgery and is re-transfused at the time of surgery. Blood can safely be stored for 21 days. It is important to liaise with the blood donor bank to ensure that the patient gets his own blood

• Do not correct post-operative anaemia with transfusion if there is no active bleeding or shock.

ANTIMICROBIAL PROPHYLAXIS IN SURGERY

Antimicrobial prophylaxis can decrease the incidence of infection particularly wound infections after certain operations but this benefit must be weighed against cost, risks of toxic and allergic reactions and emergence of resistant bacteria. The administration of antibiotic agents to prevent infection cannot be substituted for either sound surgical judgement or strict aseptic technique. Surgical wounds may be designated as clean, contaminated, dirty.

• Clean wounds - Chemoprophylaxis has no place in clean operative procedures.

• Contaminated wounds - e.g. operations involving interior of respiratory, urinary or gastrointestinal tracts, chemoprophylaxis may be useful.

• Dirty wounds - Most traumatic wounds are highly contaminated and apart from chemoprophylaxis a thorough surgical toileting is necessary. Other highly contaminated wounds involve operations on the large intestines and severe burns.

Other high risk factors include:

• Development of infection because of malnutrition, impoverished blood supply, obesity, old age and immunodeficiency states

• Treatment- specific factors such as use of steroids, anticancer agents and radiotherapy

• Operative procedures of long duration such as cardiac and vascular procedures, orthopaedic and in neurosurgery

• Insertion of a prosthesis or graft.

Management

• Prophylactic use of antibiotics should be distinguished in dosage and duration from their therapeutic use.

• A single dose of parenteral antimicrobial given with induction of anaesthesia before an operation usually provides adequate tissue concentrations for several hours.
OR 3 dose cover of same antibiotic for 24 hours
OR 5 day cover if need be.

Choice of prophylactic antibiotic

POST-OPERATIVE CARE

This is the care given in the post-operative period to:

• Keep the patient comfortable and give adequate analgesia

• Offer supportive feeding and

• Restore normal health and independence.

To achieve the above, the surgeon must give legible, concise and clear post-operative instructions.

Immediate post-operative recovery phase

• Usually in a recovery ward in theatre for about 1-2 hrs where facilities allow

• The patient is kept in semiprone position with extended neck and flexed limbs

• Maintain clear airway using oropharyngeal airway

• BP TPR ½ hrly

• Keep till awake (arousable).

Transit from theatre to ward

• Keep airway clear to avoid upper airway obstruction and aspiration pneumonitis.

Post-operative care in first 24 hours

• Continue observation BP TPR 4 hourly or as often as individual case demands

• Relieve pain with analgesia e.g. pethidine 50-100 mg every 6 hrs for adults and in children 1 mg kg in divided doses

• Transfuse if necessary

• If not feeding, give IV fluids, Hartmann's/Normal saline 5%, or 10% dextrose, about 4 litres in 24 hours for a 70 kg adult. Titrate against state of hydration

• Watch for airway obstruction, reactionary bleeding, etc.

• Attend to drains if in-situ and make sure they are draining

• Maintain input and output chart (urine output 1-2 ml/kg/hour)

• Offer general nursing care e.g. turn in bed and change wet linen to avoid bed sores

• Wound care as appropriate.

Post-operative period 72 hrs-7 days

• Mobilise out of bed about 18-72 hrs to avoid static pneumonia and deep vein thrombosis

• Encourage independence e.g. self feeding, attention to calls of nature

• Can have oral medication

• Observe at 6 hrly or BD

• Wound care as appropriate.