preoperative preparation pdf - د صباح نوري

SURGERY

Anaesthesia

DR. SABAH

AFTER MID

TOTAL LEC: 2 LEC:1

Dr. Sabah

Pre-Operative
preparation

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Anaesthesia

REOPERATIVE PREPARATION

Introduction:

IMS OF THE PREOPERATIVE VISIT

1. To ensure that the patient is presented for theatre in an optimum state.

2. It offers an opportunity to discuss the anaesthetic technique with the

patient.

3. To minimize the patient anxieties.

4. To prescribe premedication

ATIENT

SSESSMENT

Cardiovascular System:

1. Coronary Artery Disease:



The role of exercise tolerance



The role of Cardio-Pulmonary Exercise Test (CPET)



Stable Angina



Unstable Angina



Previous Myocardial Infarction

صباح نوري السعد

M.B.Ch.B, D.A,

F.I.M.S, C.A.B.A & I.C

Lecture: 1

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2. Cardiac Failure:

Careful assessment especially if the patient has basal crepitations or

Gallop rhythm.

3. Arrhythmias:



History of palpitation or stokes-Adams attacks



Infrequent ectopics are rarely significant unless associated with

electrolytes imbalance, or thyroid disease.



Usually diagnosed accurately by ECG.



Certain arrhythmia requires control or correction before operation, e.g.

rapid atrial fibrillation (AF), or 2

and 3

degree heart block.

4. Hypertension: Hypertension should be treated before operation:



Patients who have their diastolic blood pressure persistently exceeds

110 mmHg require control before operation.



Mild-moderate hypertension require control if hypertension is

associated with end-organ damage.



Hypertensive patient on treatment but still their hypertension not

adequately controlled.



All antihypertensive medications should be continued up to including

the day of surgery.

II. Respiratory System:

Upper Airway: Lips – Trachea



Mouth Opening



Presence of diseased teeth or dentures



Cervical spine mobility



Thyro-mental distance

2. Chronic Obstructive Airway Disease (including Asthma)

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

Severity of the disease can be assessed by: exercise tolerance, current

medication, frequency of hospital admission.



Physical signs such as cyanosis and wheezes are important in more

severe disease



Chest X-Ray although routinely taken but rarely helps.



Pulmonary Function Test (PFT) is usually performed, Peak Expiratory

Flow Rate (PEFR).



Patient with severe disease requires early admission.



Local and Regional Anaesthesia is preferred.

3. Upper and lower respiratory tract infections

Elective surgery should be delayed; otherwise life-threatening respiratory

tract infection may develop post-operatively.

III. Endocrine Diseases:

1. Diabetes Mellitus:



Usually they have cardiovascular and renal diseases.



The most common practical problem is the management of diabetes

mellitus during inevitable period of starvation



Random Blood Sugar (RBS) below 15 mmol/L is acceptable



General principles of management under General Anaesthesia:

1. Hypoglycaemia must be avoided

2. Regular measurements of random blood sugar is important

3. Insulin-Dependent diabetics require insulin even during starvation

and they require more insulin than usual.

4. Non-Insulin-Dependent diabetics may require insulin for a brief

period.

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A suggested scheme for management of diabetic patient undergoing elective

surgery:

Type of Diabetes

Minor Surgery

Major Surgery

1. Diet controlled

 Measure blood sugar

 Rarely require treatment

 Measure blood sugar

 Rarely require insulin

2. Oral treatment

 Measure blood sugar

 Omit treatment 12-24 hours

before operation

 Measure blood sugar

 Omit treatment 12-24 hours

before operation

 Both groups may require insulin after operation

3. Insulin-dependent

For both operation:

 measure blood sugar

 insulin (injection or infusion) + 5% dextrose infusion

(together or separately)

2. Thyroid Disease:



Patient with thyroid disease should have Thyroid Function Test before

elective surgery.



Uncontrolled hyperthyroidism

Thyroid Crises



Myxoedema

Delayed Recovery and Heart Failure



Clinical judgement and high index of suspicion is important.

IV. Neuromuscular System:

1. Epilepsy:



Avoid anaesthetic drugs which are suspected of being epileptogenic

(Ketamine)



Continue anticonvulsant medications including the day of surgery, and

as soon as possible post-operatively.

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راجعو شوية شكلكم ممضبطيها المحاظرة:D

2. Lower Motor Neuron disease:

Altered response to suxamethonium → hyperkalemia

3. Myasthenia Gravis:



assessment of severity



Highly sensitive to non-depolarizing muscle relaxants



Planning for post-operative intensive care unit (ICU) admission and

possibly mechanical ventilation.

4. Malignant Hyperthermia:



Runs in families



Hypermetabolic stat of skeletal muscles is triggered

hyperthermia and electrolyte imbalance.

5. Stroke:



There is no post-stroke “Risk Period”



It makes sense not to undertake elective surgery during recovery from

stroke



Good control of hypertension

V. Genito-urinary System:

1. Renal Failure:



The pathophysiology of Renal Failure whether acute or chronic is

complex



Chronic renal failure:

o Hypertension, cardiomyopathy, pericardial effusion

o Anaemia and platelet dysfunction

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o Impaired Blood-Brain barrier (highly sensitive to opioid analgesics

especially Morphine).

o Fluid and Electrolyte imbalance

o Dialysis may be required before operation.

2. Pregnancy

Elective surgery is contraindicated



Early pregnancy → Teratogencity of anaesthetics



Late pregnancy → Premature labour

VI. Haematological System:

1. Anaemia: Lowest Hemoglobin for elective surgery is 10 mg/dL except

chronic renal failure patients.

2. Clotting Disorders: chronic liver disease, primary haematological

disease, or drug (warfarin)

VII. Concurrent drug treatment: these might interact with anaesthetic drugs;

RUG

FFECT

A. Cardiovascular system:

1. Potent

antihyperensives,

e.g. β-

Blockers, ACE Inhibitors

→ Enhance hypotensive effect of general

anaesthesia or spinal anaesthesia

2. Antiarrhythmics,

e.g.

Digoxin,

amiodarone

→ Increased risk of bradycardia ± significant

myocardial depression, digoxin may cause

significant arrhythmia

3. Diuretics, e.g. thiazide, spironolactone → Dehydration ± electrolyte imbalance

4. Anticoagulant, e.g. warfarin

→ Major regional block contraindicated

B. Respiratory system:

Bronchodilators, e.g. Aminophylline

→ Increased likelihood of arrhythmia

C. Central Nervous System:

1. Sedative and hypnotics

→Chronic use induce tolerance to general

anaesthesia

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2. Monoamine Oxidase

→ Interact with sympathomimetic

(ephedrine), and pethidine to cause

hypertension and tachycardia → Fatal

3. Antiparkinson drugs

→ Levodopa increase risk of arrhythmia

4. Antiepileptics

→ Increase tolerance to general anaesthesia

D. Drug of abuse

1. Tobacco

→  Reduce O

carriage capacity by

formation

Carboxyhemoglobin

(COHb)

 Major Factor in chronic obstructive

airway disease

 May induce tolerance to general

anaesthetics

2. Alcohol

→  Tolerance to anaesthetics

 Chronic use may cause cirrhosis and

cardiomyopathy

3. Intravenous drug abuse

→  Tolerance to effects of opioids

 Risk of hepatitis and AIDS

 May have difficult veins

E. Steroids: glucocorticoids

→ currently or in the previous 6 months

cause adrenocortical suppression

F. Oral Contraceptive Pills (OCP)

1. Oestrogen-containing OCP

→ Deep venous Thrombosis and pulmonary

embolism

N.B: Should be stopped 1 month before

elective operation

2. Progesterone-only OCP

→ No effect

G. Aspirin and Clopidogrel (Plavix)

→ Platelet dysfunction, better to be stopped

at least 1 week before elective operation.

In coronary stenting better not to stop

clopidogrel

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Thank you

Done by: Hussein Sadun Al-Nuaimy