This document provides information on various anesthetics and anesthesia-related topics. It discusses the order of sensation loss in local and spinal anesthesia. It then describes the characteristics of commonly used anesthetics such as prilocaine, succinylcholine, atracurium, cocaine, nitrous oxide, ether, halothane, enflurane, isoflurane, sevoflurane, thiopentone sodium, propofol, ketamine, fentanyl/droperidol, etomidate, and trilene. Other topics covered include muscle relaxants, gas cylinder color codes, elements of primary survey, contraindications to spinal anesthesia, and additional anesthesia-related terms and conditions.

1. ANAESTHESIA
ORDER OF SENSATION LOSS IN
LOCAL ANAESTHESIA
ORDER OF SENSATION LOSS IN
SPINAL ANAESTHESIA
Temperature
Pain
Touch
Deep pressure
Preganglionic b fibres
Cold
Warm
Pin prick
Pain
Touch
Pressure
Motor
Vibration / proprioception
CHARACTERISTICS OF SOME COMMONLY USED ANAESTHETICS
Prilocaine Safest local anaesthetist
Produces methemoglobinemia
Succinylcholine Non-competitive muscle relaxant
Used during intubation.
Produces fasciculations
Produces biphasic block
Significant hyperkalemia with Succinylcholine is seen in
Burns, paraplegia, tetanus
Atracurium Undergoes Hoffman elimination
Used in hepatic and renal failure
Cocaine Naturally occurring
Produces vasoconstriction
Peripheral sympathomimetic action
Nitrous oxide Second gas effect
Diffusion hypoxia
Only analgesic effect
It inactivates cobalt in vitamin B 12 ; irreversibly inactivates enzyme
Methionine synthetase
Megaloblastic anaemia occurs after exposure for periods of more than
3-12 hours.
It can be prevented by pretreatment with Foilnic acid
Ether Inflammable
Causes increased blood glucose levels in diabetics
TRIVIAL TRUTH
Every year, surgical tools are left in approximately 1,500 patients in the USA. Fatter
patients are more prone to having a surgical tool left inside of them due to the additional
amount of space in their bodies.
ELEVENTH HOUR ANAESTHESIA 194

2. CHARACTERISTICS OF SOME COMMONLY USED ANAESTHETICS
CONTINUED…
Halothane Useful in
Asthmatics, version, uterine relaxation (hence not used in post-partum
hemorrhage as relaxant effect increases bleeding)
Increases ICT (intracranial tension)
Sensitizes heart to Cathecholamines.
Side-effects-
Hepatitis, malignancy, hyperthermia, shivering.
Postoperative shivering is managed with Tramadol, Pethidine, and
Pentazocine.
Should not be used again in next three months
Enflurane Contraindicated in epilepsy
Isoflurane Decreases ICT
Used in myocardial infarction, neurosurgery, alcoholic cirrhosis.
Sevoflurane Fastest induction
Used in pediatric surgery
Not used in closed circuit with soda-lime.
Thiopentone
sodium
Highly lipid soluble
Contraindicated in acute Porphyria.
Propofol Day care surgery
Ketamine Dissociative anesthesia
Used in head, neck surgery, angiography, cardiac catheterization, burn
dressing
Preferred in asthmatics, Porphyria
Avoided in- MI, hypertension
Fentanyl/
Droperidol
Neurolept analgesia , Used in endoscopy
Etomidate Causes adrenal cortex suppression
Pain on injection
No analgesic effect
preferred in Porphyrias
Trilene Maximum analgesia.
Not to be used with soda-lime
Longest acting local anesthetist Shortest acting anesthetist
Dibucaine > Tetracaine > Bupivacaine Chlorprocaine
Lignocaine maximum dose
Without adrenaline
Lignocaine maximum dose
With adrenaline
3 mg/kg= 200mg (average adult) 7 mg/kg = 500mg (average adult)
QUOTE CORNER
Learning without thought is labour lost, thought without learning is perilous.- Confucius

3. ELEVENTH HOUR ANAESTHESIA
195
Longest acting muscle relaxant Shortest acting muscle relaxant
Doxacurium > Pipecuronium > Pancuronium
> d-Tubocurare.
Succinylcholine < Mivacurium
MUSCLE RELAXANTS CONDITION
In renal failure Vecuronium / Atracurium
In hepatic failure Atracurium
Myasthenia gravis 1/10th
Atracurium
Short cases Atracurium / Ropacurium / Mivacurium
Obstetrics All except Gallamine
Arterial surgery Pancuronium
To reduce blood pressure Tubocurare
Rapid sequence induction Rocuronium / Ropacurium
Asthmatics Pancuronium (avoid Metacurine and Succinylcholine)
Carcinoid tumour Vecuronium
Aminoglycosides causing neuromuscular blockade
Neomycin > Streptomycin > Gentamycin
COLOUR CODING OF GAS CYLINDERS
GASES COLOUR CODES
Oxygen Black body with white shoulders
Nitrous oxide Blue
Carbon dioxide Grey
Cyclopropane Orange
Air Grey body , black and white quartered shoulders
Entonox Blue body, white and blue quartered shoulders
PIPED GAS SUPPLIES
White Oxygen
Blue Nitrous oxide
Black Compressed Air
Yellow Vacuum
ELEMENTS OF PRIMARY SURVEY
Airway with cervical spine control
Breathing and ventilation
Circulation with control of hemorrhages
Dysfunction of central nervous system
Exposure in a controlled environment
TRIVIAL TRUTH
In 1980, a Las Vegas hospital suspended workers for betting on when patients would die.

4. ELEVENTH HOUR ANAESTHESIA 196
CONTRAINDICATIONS TO SPINAL ANESTHESIA
Hypotension and hypovolemia
Uncooperative and mentally ill person
Infants and children
Vertebral abnormalities
Local sepsis
*Malignant hyperthermia is autosomal dominant
Seen with Halothane, Ether and Succinylcholine
Due to excessive release of Ca++
from sarcoplasmic reticulum.
*Circuit used in spontaneous respiration is Mapleson A
*Eutectic Lignocaine + Prilocaine –
Decreases the melting point of the mixture.
Useful in surface anaesthesia.
TEMPE-Topical Eutectic Mixture for Premature Ejaculation.
*Madelson’s syndrome-
Bilateral diffuse alveolar opacities caused due to aspiration of acid gastric contents after
anesthesia, alcohol abuse, drug overdose, epilepsy.
*Bier’s block- regional anaesthesia that utilizes intravenous injection of the local
anaesthetic agent to bring it to the nerve trunks and endings.
QUOTE CORNER
There is no happiness except in the realization that we have accomplished something.-
Henry Ford
ELEVENTH HOUR ANAESTHESIA
197