Routine preoperative investigations Check local hospital policy.

• Urinalysis

• ECG

• All patients: for sugar, blood and protein

• Age> 50 years• History of heart disease,

hypertension or chronic lung disease

• A normal previous trace within 1 year is acceptable unless there is a recent cardiac history

• FBC

• Blood urea, electrolytes and creatinine

• Males > 40 years • All females• All major surgery

• Whenever anemia is suspected

• Age >50 years

• All major surgery Diuretic drugs

• Suspected renal disease

• Blood glucose

• Coagulation screen

• Sickle cell test

• Diabetic patients• Glycosuria• Age > 50 years

• History of bleeding tendency (some units measure before major surgery)

• Black patients with unknown sickle status. If positive then hemoglobin electrophoresis should be performed

• Pregnancy test

• Chest radiograph

• whenever there is any chance of pregnancy

• Not routine• Acute cardiac of chest

disease• Chronic cardiac or chest

disease that has worsened in the last year

• Risk of pulmonary TB (recent arrival from the developing world or immunocompromis)

• Malignant diseases

Consent

• All competent patients have to give or with hold consent for treatment or examination

• To obtain consent , the patient must be given sufficient details and information about the procedure to enable proper decision to be taken

• In an emergency, consent is not necessary for life-saving procedures

•Risk

In order to appreciate risk the patient needs to be told of the likelihood of the complication occurring and this should be put into context by using an analogy from everyday life

• Negligible risk frequency less than 1:1000 000, i.e. the risk of dying from lightening strike.

• Minimum risk: frequency 1: 100 000-1000 000, i.e. the risk of dying on the railways

• Very low risk: frequency 1: 10 000-1:100 000 i.e. the annual risk of dying of traffic accident at home or at work

• Low risk: frequency 1-1000-10 000, i.e. the annual risk of dying in a road traffic accident.

• Moderate risk: frequency 1: 100 to 1:1000 i.e. the risk of death from natural causes for patients over 40 within the next year

• High risk : frequency greater than 1: 100 the risk of developing diarrhea after antibiotics

In addition to the frequency of the risk, the

seriousness must be considered

Competence

Adult patients who are able to make decision on their own about their treatment are considered competent. This means that they must be capable of understanding and remembering the information given about the procedure, and be able to weigh up the risks and benefits to arrive at a balanced choice. For competent patients, no other person can consent or refuse treatment on their behalf

Restricted consent

• Some patients may consent to treatment in general, but refuse consent for certain aspects of the treatment, e.g. Jehovah's Witness patients who refuse blood transfusion

• The patient's wishes must be respected

ResearchAll clinical research requires Research Ethics Committee approval

TeachingStudents must not take part in clinical procedures

without the patients consent

DocumentationThe anesthetic plan discussed and agreed with the

patient should be documented including the risks which have been explained

Physical status classification of the American Society of Anesthesiologists (ASA)

• Physical Status

Classification

PS-1

• Description

a normal healthy patient

• PS-2 • A patient with mild systemic disease that results in no functional limitation Examples: Hypertension. Diabetes mellitus, chronic bronchitis. Morbid obesity, extremes of age

• PS-3 • A patient with severe systemic disease that results in functional limitation

• Examples: Poorly controlled hypertension. Diabetes mellitus with vascular complication, angina pectoris, prior myocardial infarction

• Pulmonary disease that limits activity

• PS-4 • A patient with severe systemic disease that is a constant threat to life

• Examples congestive heart failure, unstable angina pectoris advanced pulmonary, renal or hepatic dysfunction

• PS-5 • A moribund patient who is not expected to survive without the operation

• Examples: Ruptured abdominal aneurysm, pulmonary embolus, head injury with increased intracranial pressure

• PS-6 • A declared brain –dead patient whose organs are being removed for donor purposes

• Emergency

Operation (E)

Any patient in whom an emergency operation is required

Example: an otherwise healthy 30-year –old female who requires dilation and curettage for moderate but persistent vaginal bleeding (PS-1E)

Fasting

• Pulmonary aspiration of gastric contents is associated with significant morbidity and mortality.

• Factors predisposing to regurgitation and pulmonary aspiration include:

• Pregnancy

• Obesity

• Difficult airway• Emergency surgery, trauma

• Full stomach

• Altered gastric motility (head injury)

• Anesthesia drugs, opioids• Metabolic causes (poorly controlled DM,

renal failure)

• Pyloric obstruction

ASA Fasting guidelines

Ingested material• Clear liquids• Breast milk

• Infant formula milk• Non human milk• Light meal

• Heavy meal (contain fat &meat)

Minimum fast

2 h

4 h

4-6 h

6 h

6 h

8 h

Approaches to the problem of Acid Aspiration

1. Decrease gastric fluid volume

• Restrict intake

• Empty stomach:

-Physical (NG-tube)

-Pharmacological (Apomorpheine)

• Suppress gastric secretion(H2-blockers, Atropine)

2. Decrease gastric fluid acidity• Neutralise existing acid (30ml sodium citrate)• Elevate pH, pharmacological (Ranitidine,

cimetidine)

3. Prevent regurgitation

• Increase tone of lower oesophageal sphincter (Metoclopromide, alkalinisation of stomach)

• Avoid increase in intra-gastric pressure (prevent fasciculation)

• Cricoid pressure

4. Prevent inhalation if regurgitation occurs

• Induction in lateral position

• Powerful sucker available

5. Avoid intubation Difficulties

• Careful patient assessment

• Skilled anesthesiologist

6. Avoid general anesthesia

• Regional or local anesthesia

Thank you