1
Chapter
INTRODUCTION TO
ANESTHESIA
NEED FOR ANESTHESIA
1. Pain Relief
2. Patient Co operation
3. Immobile patient during surgery
4. Unconsciousness (not mandatory though)
5. Muscle relaxation
6. Controlled blood pressure to reduce bleeding during surgery
7. Amnesia → Selective memory loss
8. Post operative pain relief through → intravenous medication, Regional technique, Patient controlled analgesia
TYPES OF ANESTHESIA
GENERAL ANESTHESIA
•• Patient is completely unconscious throughout the surgery.
•• STEPS OF GENERAL ANESTHESIA :
1. PRE MEDICATION → given outside OT
2. Attach monitors
•• ECG
•• sPO2
•• Temperature
•• Non invasive Blood pressure (NIBP)
•• Temperature monitoring
•• Capnography / eTCO2
3. Secure intravenous access
4. Induction of Anesthesia (IV route or Inhalational route)
5. IV route is preferred as compared to inhalational induction as there is FASTER induction of anesthesia
6. Once patient becomes unconscious, Muscle relaxant is given to paralyze patient
7. Laryngoscopy and intubation done to insert endotracheal tube and connect to ventilator
8. Maintainence of anesthesia by inhalational agent
9. Top up of muscle relaxant given till end of surgery
,254
Anesthesia Notes
10. At the end of surgery → REVERSE ACTION OF MUSCLE RELAXANT by giving: NEOSTIGMINE AND
GLYCOPYRROLATE: UNPARALYSE PATIENT
11. Switch off anesthetic agent
12. Wake up patient and Extubate
NOTE : INHALATIONAL INDUCTION OF ANESTHESIA: Commonly done in CHILDREN
Q. WHICH OF THESE IS A COMPONENT OF GENERAL ANESTHESIA?
A. LOSS OF REFLEX RESPONSE
B. AMNESIA
C. MUSCLE RELAXATION
D. ALL OF THE ABOVE
Q. WHICH OF THE FOLLOWING HAS NO CONTRAINDICATION?
A. GENERAL ANESTHESIA
B. REGIONAL ANESTHESIA
C. TIVA
D. NONE OF THE ABOVE
PRE MEDICATION : (Classes of drugs)
1. ANXIOLYTICS : Benzodiazepines (Short acting)
2. ANALGESICS : Pain relief – Opioids, Paracetamol, NSAIDS
3. ANTI EMETICS : Inj. Emset (ondansetron) / prokinetics / steroids
4. ANTISIALAGOGUES: Anti secretory agents: Gycopyrrolate and Atropine
5. COUNTER GASTRIC ACIDITY: PPI (Proton Pump Inhibitors) and H2 Antagonists
CANNULA SIZES
14 G : ORANGE → 270 mL/min
16 G : GREY – 236 mL/min
18 G : GREEN – 103 mL/min
20 G : PINK – 67 mL/min
22 G : BLUE – 31 mL/min
24 G : YELLOW -13 mL/min
26 G : PURPLE
NOTE : 14 G: BIGGEST CANNULA, 26 G: SMALLEST CANNULA
1. 24 G AND 26 G → Used in pediatric age group
2. 16 G, 18 G → Preferred for blood transfusion
, 255
Introduction to Anesthesia
BASIC MONITORING
Non invasive blood pressure (NIBP) ECG Temperature
SPO2 Capnography
REGIONAL ANESTHESIA
•• Blocking the sensation / motor movement from one part of the body
•• No Amnesia / unconsciousness but patient will have no pain in the part being operated upon
Regional Anesthesia can be broadly classified into
1. CENTRAL NEURAXIAL BLOCKADE
•• SPINAL ANESTHESIA
•• EPIDURAL ANESTHESIA
•• CAUDAL ANESTHESIA
A. SPINAL ANESTHESIA
•• Local anesthetic given in Subarachnoid space, which spreads through the CSF and blocks the spinal
nerves leading to loss of sensation and motor function
B. EPIDURAL ANESTHESIA
•• Local anesthetic given in epidural space
•• Requires more drug compared to spinal anaesthesia
•• Safer
C. CAUDAL ANESTHESIA
•• Given in children < 8 years
•• Needle inserted through sacral hiatus → Sacrococcygeal membrane is pierced → Local anesthetic is given
in epidural space
•• After 8 years : Sacral hiatus fuses
3. PERIPHERAL NERVE BLOCKADE
Individual nerves are seen under ultrasound guidance / stimulated using peripheral nerve locator and blocked
with local anesthetic
, 256
Anesthesia Notes
Examples:
A. SCIATIC NERVE BLOCK
B. BRACHIAL PLEXUS BLOCK
CONTRAINDICATIONS FOR REGIONAL ANESTHESIA
•• Allergy to local anesthetic
•• Patient refusal
•• Infection at site of needle insertion
•• Coagulopathy
•• Uncorrected hypotension/ Sepsis
MONITORED ANESTHESIA CARE :
Q. A patient is to be taken for colonoscopy. He is very anxious. He also gives history
of recent myocardial infarction and is on anti coagulants. The surgeon wants mid
anxiolysis to carry out procedure uneventfully. What is the anesthesia of choice in
this procedure?
A. GENERAL ANESTHESIA
B. REGIONAL ANESTHESIA
C. MONITORED ANESTHESIA CARE
D. ANY OF THE ABOVE
Monitored Anesthesia Care involves only monitoring the patient (without giving
anesthesia). It is done in :
•• High Risk patients
•• Low risk short procedure
•• Sometimes mild sedation / anxiolysis can be given to the patient
SCIENTISTS IN ANESTHESIA
•• Father of modern anesthesia ether anesthesia – WTG MORTON
•• Father of anesthesia – JOHN SNOW
•• Word anesthesia coined by – OLIVER WENDELL HOLMES
•• Used curare products for the first time for muscle relaxation – HAROLD GRIFFITH
•• Used cocaine for the first time for anesthesia – AUGUST BIER
•• First intubation done by – WILLIAM McEWAN
•• Oxygen and nitrous oxide synthesised by – PRIESTLY
•• First demonstration of nitrous oxide - HORACE WELLS
•• Introduced chloroform to obsteric anesthesia – JAMES SIMPSON
•• First anesthesia machine used by – EDMUND BOYLE
•• First prize in anesthesia – BOVET
•• WORLD ANESTHESIA DAY – 16th OCTOBER 1846
•• Balanced anesthesia definition given by – LUNDY
Chapter
INTRODUCTION TO
ANESTHESIA
NEED FOR ANESTHESIA
1. Pain Relief
2. Patient Co operation
3. Immobile patient during surgery
4. Unconsciousness (not mandatory though)
5. Muscle relaxation
6. Controlled blood pressure to reduce bleeding during surgery
7. Amnesia → Selective memory loss
8. Post operative pain relief through → intravenous medication, Regional technique, Patient controlled analgesia
TYPES OF ANESTHESIA
GENERAL ANESTHESIA
•• Patient is completely unconscious throughout the surgery.
•• STEPS OF GENERAL ANESTHESIA :
1. PRE MEDICATION → given outside OT
2. Attach monitors
•• ECG
•• sPO2
•• Temperature
•• Non invasive Blood pressure (NIBP)
•• Temperature monitoring
•• Capnography / eTCO2
3. Secure intravenous access
4. Induction of Anesthesia (IV route or Inhalational route)
5. IV route is preferred as compared to inhalational induction as there is FASTER induction of anesthesia
6. Once patient becomes unconscious, Muscle relaxant is given to paralyze patient
7. Laryngoscopy and intubation done to insert endotracheal tube and connect to ventilator
8. Maintainence of anesthesia by inhalational agent
9. Top up of muscle relaxant given till end of surgery
,254
Anesthesia Notes
10. At the end of surgery → REVERSE ACTION OF MUSCLE RELAXANT by giving: NEOSTIGMINE AND
GLYCOPYRROLATE: UNPARALYSE PATIENT
11. Switch off anesthetic agent
12. Wake up patient and Extubate
NOTE : INHALATIONAL INDUCTION OF ANESTHESIA: Commonly done in CHILDREN
Q. WHICH OF THESE IS A COMPONENT OF GENERAL ANESTHESIA?
A. LOSS OF REFLEX RESPONSE
B. AMNESIA
C. MUSCLE RELAXATION
D. ALL OF THE ABOVE
Q. WHICH OF THE FOLLOWING HAS NO CONTRAINDICATION?
A. GENERAL ANESTHESIA
B. REGIONAL ANESTHESIA
C. TIVA
D. NONE OF THE ABOVE
PRE MEDICATION : (Classes of drugs)
1. ANXIOLYTICS : Benzodiazepines (Short acting)
2. ANALGESICS : Pain relief – Opioids, Paracetamol, NSAIDS
3. ANTI EMETICS : Inj. Emset (ondansetron) / prokinetics / steroids
4. ANTISIALAGOGUES: Anti secretory agents: Gycopyrrolate and Atropine
5. COUNTER GASTRIC ACIDITY: PPI (Proton Pump Inhibitors) and H2 Antagonists
CANNULA SIZES
14 G : ORANGE → 270 mL/min
16 G : GREY – 236 mL/min
18 G : GREEN – 103 mL/min
20 G : PINK – 67 mL/min
22 G : BLUE – 31 mL/min
24 G : YELLOW -13 mL/min
26 G : PURPLE
NOTE : 14 G: BIGGEST CANNULA, 26 G: SMALLEST CANNULA
1. 24 G AND 26 G → Used in pediatric age group
2. 16 G, 18 G → Preferred for blood transfusion
, 255
Introduction to Anesthesia
BASIC MONITORING
Non invasive blood pressure (NIBP) ECG Temperature
SPO2 Capnography
REGIONAL ANESTHESIA
•• Blocking the sensation / motor movement from one part of the body
•• No Amnesia / unconsciousness but patient will have no pain in the part being operated upon
Regional Anesthesia can be broadly classified into
1. CENTRAL NEURAXIAL BLOCKADE
•• SPINAL ANESTHESIA
•• EPIDURAL ANESTHESIA
•• CAUDAL ANESTHESIA
A. SPINAL ANESTHESIA
•• Local anesthetic given in Subarachnoid space, which spreads through the CSF and blocks the spinal
nerves leading to loss of sensation and motor function
B. EPIDURAL ANESTHESIA
•• Local anesthetic given in epidural space
•• Requires more drug compared to spinal anaesthesia
•• Safer
C. CAUDAL ANESTHESIA
•• Given in children < 8 years
•• Needle inserted through sacral hiatus → Sacrococcygeal membrane is pierced → Local anesthetic is given
in epidural space
•• After 8 years : Sacral hiatus fuses
3. PERIPHERAL NERVE BLOCKADE
Individual nerves are seen under ultrasound guidance / stimulated using peripheral nerve locator and blocked
with local anesthetic
, 256
Anesthesia Notes
Examples:
A. SCIATIC NERVE BLOCK
B. BRACHIAL PLEXUS BLOCK
CONTRAINDICATIONS FOR REGIONAL ANESTHESIA
•• Allergy to local anesthetic
•• Patient refusal
•• Infection at site of needle insertion
•• Coagulopathy
•• Uncorrected hypotension/ Sepsis
MONITORED ANESTHESIA CARE :
Q. A patient is to be taken for colonoscopy. He is very anxious. He also gives history
of recent myocardial infarction and is on anti coagulants. The surgeon wants mid
anxiolysis to carry out procedure uneventfully. What is the anesthesia of choice in
this procedure?
A. GENERAL ANESTHESIA
B. REGIONAL ANESTHESIA
C. MONITORED ANESTHESIA CARE
D. ANY OF THE ABOVE
Monitored Anesthesia Care involves only monitoring the patient (without giving
anesthesia). It is done in :
•• High Risk patients
•• Low risk short procedure
•• Sometimes mild sedation / anxiolysis can be given to the patient
SCIENTISTS IN ANESTHESIA
•• Father of modern anesthesia ether anesthesia – WTG MORTON
•• Father of anesthesia – JOHN SNOW
•• Word anesthesia coined by – OLIVER WENDELL HOLMES
•• Used curare products for the first time for muscle relaxation – HAROLD GRIFFITH
•• Used cocaine for the first time for anesthesia – AUGUST BIER
•• First intubation done by – WILLIAM McEWAN
•• Oxygen and nitrous oxide synthesised by – PRIESTLY
•• First demonstration of nitrous oxide - HORACE WELLS
•• Introduced chloroform to obsteric anesthesia – JAMES SIMPSON
•• First anesthesia machine used by – EDMUND BOYLE
•• First prize in anesthesia – BOVET
•• WORLD ANESTHESIA DAY – 16th OCTOBER 1846
•• Balanced anesthesia definition given by – LUNDY
