This document discusses general considerations for anaesthesia. It covers topics like the definition of anaesthesia, evaluation of patients for general anaesthesia including anamnesis, physical examination, haematological and biochemical examination. It also discusses anaesthetic considerations for specific conditions and surgeries like trauma, renal disease, urinary tract obstruction, gastric surgeries, intestinal surgeries, diabetes, hypothyroid/hyperthyroid patients, pediatrics and caesarean section. Key factors discussed include monitoring, supportive therapy, choice of anaesthetic agents and dosages depending on the condition of the patient.

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GENERAL CONSIDERATONS
FOR ANAESTHESIA
Submitted To-Dr.Adarsh Thakur
Submitted By- Manpreet Singh

2. z
ANAESTHESIA
 Refers to the state in which an animal is insensible to pain
resulting from the trauma or surgery.
 The term ‘analgesia’ is Greek word for ‘without pain’.
 The term ‘anaesthesia’ was coined by Oliver Wendell Holmes
in 1846 .
Aim Of Anaesthesia
 Humane treatment of the animal
 Provision of adequate conditions for the procedure

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EVALUTION OF PATIENTS FOR
GENERAL ANAESTHESIA
 ANAMNESIS
 PHYSICAL EXAMINATION
 HAEMATOLOGICAL EXAMINATION
 BIOCHEMICAL EXAMINATION
 MEDICATION AND FLUIDS
 CONCURRENT DISEASE
 SCREENING TESTS

4. z
ANAMNESIS
AGE
 Geriatric Patients- cardiopulmonary,hepatic;renal system should be
evaluated properly. Short acting, easily eliminated at low end of the dose
range. Use balanced anaesthetic technique to avoid using higher dose.
 Paediatric Patients- low dose is required because of insuffiency of
hepatic microsomal enzymes.
SIZE OF PATIENT
 Small animal has higher BMR therefore more dose is required than in large
animals.

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SEX OF THE ANIMAL-
 BMR of male animals is app.7% higher than female animals .
 In females BMR rise occur during pregnancy.
TEMPRAMENT AND ACTIVITY-
 Active animals have high value of BMR

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 BREED-
 Greyhounds -sensitive to thiopental
 -Prolonged recovery from propofol
 Brachiocephalic breeds-challenging intubation
 -Risk of airways obstruction
 - Choice of endotracheal tube size
 Toy breeds - hypothermia
 Giant breeds -require lower drug dosages
 - Body weight ratio e.g. Boxer breed
sensitive to ACP

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PHYSICAL EXAMINATION
 TEMPERATURE
 RESPIRATION RATE
 HEART RATE
 BLOOD PRESSURE
 BODY SCORE
 DEHYDRATION STATUS

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HAEMATOLOGICAL EXAMINATION
 HAEMOGLOBIN
 PCV
 TLC ,DLC
 MCV
 MCHC
 PLATELLETS

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BIOCHEMICAL EXAMINATION
 BUN
 CREATININE
 AST
 ALT
 SERUM CALCIUM

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PREVIOUS MEDICATION
Organophoshates,Carbon
tetrachloride,Tetracyclines
Inhibition of hepatic microsomal
enzymes
Prolong half life of
Barbiturates,Narcotics and LA.
ENZYME INHIBITORS-

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DRUG INTRACTION
ANTIBIOTICS
Cause neuromuscular
blockade
Intensify effect of non
depolarising NM blocking
agents

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 BLOOD GAS ANALYSIS
 BLOOD PRESSURE MEASUREMENT
 ELECTROCARDIOGRAPHY

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MULTIPARA MONITORING

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CENTRAL VENOUS PRESSURE MEASUREMENT

17. zANESTHETIC CONSIDERATIONS IN
TRAUMA AND SHOCK PATIENT
MONITORING
CVP –Measures direct atrial blood pressure
OSCILLOMETRIC TECHNIQUE -Most accurate in cats
SUPPORTIVE THERAPY - (fluids and electrolyte)
Two intravenous catheters can be placed @ Dogs -90ml/kg body weight
Cats – 70ml/kg body weight
o Plasma extenders preoperatively
o Hypoglycaemia due to shock -5% dextrose
o In severe blood loss -whole blood transfusion

18. zANESTHETIC CONSIDERATIONS IN
RENAL PATIENTS
 KIDNEYS - An important pathway in elimination of high ionized drugs and
polar metabolites of drugs (which undergo biotransformation by liver)
 EXAMPLE- ketamine in cats
AZOTEMIA
LOW ALBUMIN LEVELS
DECREASED PLASMA PROTEIN
BINDING OF DRUG

19. z PATIENT WITH URINARY TRACT
OBSTRUCTION

20. z
ANAESTHETIC CONSIDERATIONS IN
OBSTRUCTIVE URINARY TRACT DISORDERS
 HYPERKALEMIA - Due to obstruction in urinary tract which leads to brady
arrythmia along with CV depressant effects
 Monitoring - ECG (T wave peaked )
- Serum potassium level

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 STABALIZATION- With 10 % dextrose
- Insulin administration
Add sodium bicarbonate if metabolic acidosis present.

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ANAESTHETIC CONSIDERATIONS IN
GASTRIC SURGERIES
 Gastric Dilation And Volvulus Hypotension
Decrease cardiac output
 Stabalization - Intravenous fluid and acid base balance
 -Pass stomach tube to decrease intragastric pressure
 Ketamine along with benzodiazepine - induction in hemodynamic
unstable patient

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ANAESTHETIC CONSIDERATION IN
INTESTINAL SURGERIES
 Correct hydration , electrolyte and acid base balance
 Withhold feed for mature animal from 12 to 18 hours and paediatric
patient from 4 -8 hours
 Administer prophylactic antibiotics from 2 days prior to surgery

25. zANAESTHETIC CONSIDERATIONS IN
DIABETIC PATIENTS
 Evaluating tests required -blood glucose
- -beta –hydroxybutyrate level
-glycosylated haemoglobin levels
 Preoperative fasting should not be more than 6 hours
 Insulin injection before surgery
 Xylazine - contraindicated in diabetic patient

26. zANESTHETIC CONSIDERATIONS IN
HYPOTHYROID AND HYPERTHYROID
PATIENTS
 Hypothyroid patient -decrease in metabolic rate , hypothermia
-ketamine and diazepam used for induction
 Hyperthyroid patients -increase basal metabolic rate
-treat with levothyroxine prior to surgery

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ANAESTHETIC CONSIDERATIONS
IN PEDIARTRIC PATIENTS
 Low % of drug binding to plasma proteins ( neonatal hypalbuminaemia)
 Low% of body fat result in inadequate drug distribution
 Hepatic metabolism and renal excretion is insufficient
 Neonatal heart has less contractile tissue hypovolemia
 High metabolic rate increase oxygen consumption

28. z
ANAESTHETIC CONSIDERATIONS
FOR CASEAREN SECTION
 Ventilation - increased to cope up with extra demand of oxygen
 Gastric motility - reduced leads to increased regurgitation and aspiration
pneumonia
 Oxygen -administered before induction to prevent foetal hypoxia
 Ultra short acting drugs are choicest agents e.g. propofol
 Ketamine is contraindicated in dogs

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