2. Outline
• Introduction
• History and Physical Examination
• Special Investigations
• Risk Assessment
• Preoperative therapy
• Premedication
• Intraoperative management
• Post-operative management
3. Introduction
• Pre-operative visit is essential to assess “fitness for
anaesthesia”
• Aims of the visit:
• -Establish a rapport
• Obtain a history and perform a physical examination
• Assess the risks of anaesthesia and surgery
• Institute preoperative management
• Prescribe premedication and plan the anaesthetic
management
• Establishment of rapport
4. History and physical Examination-
History
• History- ask direct questions about allergy,
infections, blood transfusion, previous
anaesthetics, diseases of the CVS and RS
• Smoking
• Alcohol
• Drug history- administration of most drugs
should be continued up to and including the
morning of operation and some should be
discontinued
5. Physical Examination
• A full PE should be undertaken and
documented in the case records
• Assessment of ease of tracheal intubation-
examine teeth for presence of caries, caps,
loose teeth and protruding upper incisors,
mouth opening, cervical spine flexion
6. Special Investigations
• Before ordering extensive investigations, the
anaesthetist should ask himself:
• -will the investigations yield information not
revealed by physical investigations?
• Will the results of the investigationalter the
management of patients?
• Guidelines: Urine analysis, HB, Eand U, Cr,LFT,
CXR, ECG,Sickle status, ABG, Sickle status
7. Risk assessment
• ASA=American Society of Anaesthesiologists
Physical status scale
• Mortality rates after anaesthesia and surgery
each ASA physical status(%)
• ASA 1 = Healthy patient (0.1)
• 11= Mild systemic disease (0.2)
• 111=moderate systemic disease (1.8)
• IV =Severe systemic disease ( 7.8)
V= Moribund patient (9.4)
8. Prediction of risk factors in general
Important factors in predicting post-op
morbidity and mortality in decreasing order:
1.Clinical assessment- ASA>3
2.Cardiac failure
3.Cardiac risk index
4.Pulmonary disease
5.Pulmonary abnormalities confirmed by X-ray
6.ECG abnormalities
9. Common causes of postponing surgery
• Acute upper respiratory tract infection
• Existing medical disease which is not under
optimum control
• Emergency surgeru for which the patient has
not been resuscitated adequately
• Recent ingestion of food- the 4-6-8 rule
• Failure to obtain informed consent
• Drug therapy
10. Preoperative therapy
• Respiratory disease- optimise
• Cardiovascular disease-e.g. hypertension
• Obstructive jaundice- start iv infusion the
night before surgery
• Blood transfusion requests- depends both on
the nature of the surgery and patient features
11. Premedication
• =administration of drugs in the period 1-2h before induction of
anaesthesia, The objectives are:
• 1. Allay anxiety and fear (Psychotherapy)
• Reduce secretion
• Enhance the hypnotic effect of general anaesthetic agents
• Reduce post op nausea and vomiting
• Produce amnesia
• Reduce the volume and increase the pH of gastric contents
• Attenuate vagal reflexes
• Attenuate sympathoadrenal responses
12. Drugs used for premedication
• Benzodiazepines eg diazepam, lorazepam
• Opioid analgesics
• Butyrophenones e.g haloperidol, droperidol
• Phenothiazines
• Anticholinergics e.g atropine, hyoscine and
glycopyrronium
13. induction
• Objective of modern anaesthesia is to rapidly
obtain a state of unconsciousness, to maintain
this state and then achieve a rapid recovery.
• Modern anaesthesia thus involves the use of
several drugs to provide hypnosis, analgesia and
muscular relaxation
• Methods available for induction
-Intravenous
- Inhalational
- Intramuscular: ketamine only
14. Tracheal intubation
• Indications – 2 major ones:
• 1. to ensure airway patency
• 2. to protect the airway from aspiration
• Airway patency important in:
- Prolonged operations
- Operations where access to the airway is difficult
- Operations involving excessive movement of the head and neck
- Use of LMA or face mask is unsuitable
- Where a major intraoperative complication develops
15. Protection from aspiration
• Use a cuffed endotracheal tube to prevent
aspiration eg for:
- Potential for vomitting and aspiration
- Situations of extensive bleeding from the
mouth, nose or oropharynx
- Thoracic operations
18. Complications following the use of Muscle
relaxants
• Inadequate ventilation
• Residual paralysis
• Prolonged apnea
19. Care of the unconscious patient
• Emergence can be associated with major morbidity, especially
from respiratory and cardiovascular complications.
• The patient may develop airway obstruction or inadequate
ventilation with subsequent hypoxaemia and hypercapnia
and is at increased risk of aspiration due to the absence of
protective airway reflexes.
• Effects of ongoing blood losses and residual drug effects
• Observation and early intervention during this period is
crucial
20. Criteria to be met before transfer from
recovery room to general ward
• Level of consciousness
-obeys command
-Spontaneous eye opening
• Respiratory system
-upper airway
-respiration
Pain control
-adequate pain control
-adequate analgesic and
anti-emetic provisions
• Cardiovascular system
-haemodynamically stable
-pulse rate acceptble
-blood pressure acceptable
-No persistent bleeding
-Peripheral perfusion
adequate
Temperature
No hypothermia or
malignant hyperthermia
21. Comparison of methods of induction
• INTRAVENOUS
• Advantages
• Rapid onset
• Dose titratable
• Depression of pharyngeal reflexes
• Anti-emetic /anticonvulsant
Disadvantages
Venous access required
Risk of hypotension
Apnoea common
Loss of airway control
anaphylaxis
• INHALATIONAL
• Advantages
• Avoids venepuncture
• Respiration is maintained
• Slow loss of protective reflexes
• End tidal concn can be measured
• Upper oesophageal tone maintained
• Disadvantages
• Slow process
• Potential excitement phase
• Irritant and unpleasnt
• Pollution
• May cause a rise in ICP/IOP
