OBJECTIVES
- History and physical examination of the patient
- To review medical records including past anaesthetic records
- To get laboratory studies
- To determine physical status and anticipate difficulties
- For planning of anaesthesia management
- To ensure obtaining consent
- To develop anaesthetist-patient rapport
- To make advanced preparation relating facilities, equipment and expertise, to enhance patient safety and minimise the chance of errors.
HISTORY
- Patient's medications: Aspirin, insulin, antihypertensives, MAO inhibitors, lithium, anticoagulants, etc.
- Any allergy
- Past hospitalisation, any anaesthesia/operation
- Family history
- Any addiction: Smoking, alcohol, drugs
- Any associated illness: Metabolic, endocrinal, renal, hepatic, cardiac, pulmonary disease, sexually transmitted disease, hepatitis, HIV
- Menstrual history in case of females.
ASSOCIATED ILLNESS NEEDING FURTHER INVESTIGATIONS
- Central nervous system: Cerebrovascular insufficiency, convulsion.
- Cardiovascular system: Chest pain, myocardial infarction, hypertension, rheumatic fever, palpitations, dysrhythmias.
- Respiratory system: Dyspnoea, cough, bronchospasm, pneumonia, smoking, upper respiratory infection.
- Liver: Alcoholism, hepatitis, jaundice
- Kidney: Polyuria, pyuria
- Endocrine system: Diabetes mellitus, adrenal dysfunction, thyroid dysfunction.
- Miscellaneous: Allergy, bleeding tendency, myalgia, arthritis, osteoporosis, strabismus, etc.
COMMON MEDICATIONS AND ANAESTHETIC IMPLICATIONS
- Aspirin: Bleeding tendency, platelet dysfunction
- Alcohol abuse: Resistance to anaesthetic drugs
- Antibiotics: Potentiation of muscle relaxants
- Antihypertensives: Impaired sympathetic nervous system activity, hypertensive crisis
- Beta blockers: Bradycardia, bronchospasm
- Benzodiazepines: Potentiation of muscle relaxants, resistance to anaesthetic drugs
- Calcium channel blockers: Interaction with muscle relaxants, hypotension
- MAO inhibitors: Increased response to sympathomimetic drugs
- Lithium: Potentiation of muscle relaxants, impaired thyroid function
- Digitalis: Dysrhythmias
- Diuretics: Hypotension, hypovolaemia, hypokalaemia
- Anticoagulant therapy: Excessive bleeding.
PHYSICAL EXAMINATION
- Vital signs: Pulse, respiration, blood pressure, body temperature
- General: Weight, weakness
- Airway examination:Cervical spine: head mobility, Mobility of temporomandibular joint, Teeth : Central incisor prominency, Artificial teeth, if any, loose teeth, Attempt of visualise uvula, any lesion in mouth, hyromental distance (Normal more than 6.5 cm)Nose and throat: Sore throat, sinusitis, epistaxis, deviated nasal septum, dysphagia, sunken cheeks, patency of nares opening of mouth. Appearance of neck (long or short).
- Respiratory: Breathing rate and pattern, any moist sound, wheezing, cough, sputum, emphysema, pneumonia, tuberculosis, bronchitis.
- Cardiac: Heart rate, rhythm, murmur, blood pressure, pulse, peripheral oedema, dyspnoea, orthopnoea, veins, heart failure.
- Central nervous system: Level of consciousness, numbness, paralysis, skeletal muscle dysfunction, convulsion.
- Gastrointestinal system: Nausea/vomiting, constipation, diarrhoea, jaundice, hepatitis.
- Haematologic: Bruising, anaemia, bleeding.
- Endocrine system: Diabetes, thyroid dysfunction.
- Urinary system: Nocturia, dysuria, haematuria, incontinence.
- Prosthesis, if any: Eye glasses, contact lens, hearing aid, ornaments, ring
- Miscellaneous: Examination of eye; examination of ear, extremities: Claudication, thrombophlebitis, arthritis; skin examination: rashes, wounds, infection; psychiatric problems, anxiety.
- Breath holding test: It is the time to hold his breath after full inspiration. Normal more than 25 seconds. Less than 15 seconds indicates severely diminished cardiorespiratory reserve.
- Match test: Patient is asked to blow off the lighted match stick with his open mouth at a distance 15 cm. Failure indicates low maximum breathing capacity.
PREOPERATIVE DIAGNOSTIC INVESTIGATIONS
- Blood examinationTC, DC, haemoglobin, haematocrit
- Blood biochemistryGlucose, urea, nitrogen, creatinine, electrolytes, liver enzymes
- Urine analysis
- Coagulation studiesProthrombin time, platelet count, partial thromboplastin time
- Chest X-ray
- Electrocardiogram
- Pulmonary function testsFEV1, vital capacity, peak expiratory flow rateArterial blood gas study, pH[Normal Values :Vital capacity 5 lits.FEV1 4 lits.PEFR 600 lits/min.PaO2 75 to 100 mm Hg.PaCO2 36 to 46 mm Hg. ]
ASA PHYSICAL STATUS INDEX
Grade 1: Normal healthy patient
Grade 2: Patient with mild/moderate systemic disease
Grade 3: Patient with severe systemic disease that causes functional limitation
Grade 4: Patient with incapacitating systemic disease that causes a constant threat to life
Grade 5: Moribund patient not expected to survive 24 hours without operation
Emergency Operation E: Any patient in whom emergency operation is required. Here the suffix E is added.
FACTORS FOR SELECTION OF ANAESTHETIC TECHNIQUE
- Safety of the patient
- Coexisting systemic disorders
- Site of operation
- Elective or emergency procedure
- Age of the patient
- Preference of the patient, if any
- Ability of the anaesthetist concerned
- Convenience of the surgeon.
PREANAESTHETIC ROUTINE PREPARATION
- Psychological support, reassurance
- No food/drink for at least 6 hours before anaesthesia
- Urinary bladder should be emptied before taken to OT
- False teeth, artificial limbs, artificial eyes, contact lenses, shoes, ornaments, etc. should be taken off
- No tight clothing, no lipstick, no nail vernish
- Adequate oral hygiene
- Identification label should be checked
- Consent for anaesthesia/surgery is mandatory
- Resuscitative drugs, fluids, etc.
- Night sedation
- Preanaesthetic medication. It should be given in adequate dose and at proper time.
- No routine preparation is needed in extreme emergencies:
- Rupture of major vessels
- Severe obstetric emergencies: ectopic rupture
- Acute upper airway obstruction
- Surgery on patients trapped and immobile.
COMMON CAUSES OF POSTPONEMENT OF OPERATION
- Acute respiratory infection
- Coexisting systemic illness not under optimal control
- Lack of adequate resuscitation
- Full stomach
- Nonavailability of written consent
- Failure to obstain recent investigation reports.
ROUTINE REQUIREMENT BEFORE INDUCTION OF ANAESTHESIA
- Anaesthesia machine
- Anaesthesia breathing system
- Gas cylinders
- Soda lime
- Vaporisers
- Mechanical ventilator
- Suction apparatus
- Monitoring equipment.
- Drugs
- Local anaesthetic drugs iv inducing agents
- Muscle relaxants
- Opioids and opioid antagonist
- Benzodiazepines and its antagonist
- Anticholinergic drugs
- Vasopressor drugs
- Bronchodilators
- Catecholamines.
- Miscellaneous
- Infusion set, fluids
- Suction catheter, oral/nasal airway
- Laryngoscope, endotracheal tubes
- Nasogastric tube, Magill forceps.
- Blood should be crossmatched and available in time.