Perioperative and
Emergency Medicine
Seán Keenan
2022
,American Society of Anaesthesiologists (ASA) Classification
American Society of Anaesthesiologists (ASA) Classification
ASA Classification Definition Examples
ASA I A normal healthy patient Healthy patient, non-smoking, no or minimal alcohol use
Mild Diseases only without substantive functional limitations. Examples include: Current
ASA II A patient with mild systemic disease smoker; Social alcohol drinker; Pregnancy; Obesity; Well-controlled DM; Well controlled
HTN; Mild lung disease
Substantive functional limitations; One or more moderate-severe diseases. Examples
include Poorly controlled DM; Morbid Obesity; Active Hepatitis; Alcohol dependence;
ASA III A patient with severe systemic disease
Implanted pacemaker; Moderately reduced RF; End-Stage Renal disease (undergoing
dialysis); Previous MI; Cerebrovascular events
Examples include recent MI (<3 months ago); Cerebrovasuclar accidents; Ongoing cardiac
A patient with severe systemic disease that is a
ASA IV ischaemia; Severe valve dysfunction; Severely reduced EF; Sepsis; DIC; ARD; End-Stage
constant threat to life
Renal Disease (not undergoing dialysis)
A moribund patient who is not expected to survive Examples include Ruptured abdominal/thoracic aneurysm; Massive trauma; Intracranial
ASA V
without the operation bleed with mass effect; Ischaemic bowel with cardiac pathology or organ dysfunction
A declared brain-dead patient whose organs are
ASA VI -
being removed for donor purposes
,Intravenous Access
Intravenous Access Cannulas
External Diameter Water Flow Rate
Colour Cannula Gauge Size Length (mm) Recommended Uses
(mm) (mL/min)
Orange 14G 2.1 mm 45 mm ~240 mL/min Trauma; Rapid blood transfusion; Surgery
Gray 16G 1.8 mm 45 mm ~180 mL/min Rapid fluid replacement; Trauma; Rapid blood transfusion
Green 18G 1.3 mm 32 mm ~90 mL/min Rapid fluid replacement; Trauma; Rapid blood transfusion
Pink 20G 1.1 mm 32 mm ~60 mL/min Most infusions; Rapid fluid replacement; Trauma; Routine blood transfusions
Blue 22G 0.9 mm 25 mm ~36 mL/min Most infusions; Neonate; Older adults; Routine blood transfusions
Yellow 24G 0.7 mm 19 mm ~20 mL/min Most infeusions; Neonate; Paediatric; Neonate or Paediatric blood transfusion
Peripheral Venous Cannula (PVC)
Description
- Use: Easy to insert with minimal morbidity - Limits: Unsuitable for vasoactives (inotropes) or
- Infusion: Wide lumen cannulae can allow for rapid irritant drugs in the long term
fluid flow rate - NB: Avoid cannulating foot in DM patients as may
- Infx: Can be rapidly identified and re-sited precipitate an ulcer and subsequent infx
Central Venous Cannula (CVC)
Description
- Use: More difficult to insert; USS usually required - Femoral: Easier and more easily managed if injury
- Coagulopathies: Bleed following iatrogenic injury - NB: Infx rate is higher
- IJV: Preferred route of access - Lumens: Multiple infusions but are narrow
Intraosseous Access
Description
- Use: Preferred in paediatric practice - Location: Dependent on age and preference
- NB: May also be used in adults - Humeral Head: Closer to heart to preferred in ALS
- Access: Marrow cavity + circulation - Proximal Tibia: Preferred in children
Tunnelled Lines
Description
- Use: Groshong + Hickman lines are popular for LT - Insertion: Usually inserted with USS guidance
administration of meds (e.g. chemotherapy) - Cuff: Anchors line; Require formal dissection
Peripherally Inserted Central Cannula (PICC) Line
Description
- Use: Peripherally situated for CVC access - NB: Less prone to major Cc than central lines
, General Anaesthetics
Anaesthetics
Route Drug MOA Adverse Effects Notes
Isoflurane Myocardial Depression Volatile liquid anaesthetics. Used for
Unknown. Combo of GABA A, Glycine
Desflurane Malignant Hyperthermia induction and maintenance of
and NDMA receptors
Sevoflurane Hepatotoxic (Halothane) anaesthesia
Inhaled
Risk of gas accumulation
Unknown. Combo of NMDA, nACh, Diffuse into gas-filled body
Nitrous Oxide E.g. CI in pneumothorax
5-HT3, GABAA and Glycine receptors compartments → Increased pressure
Headache and Nausea
Pain on injection Anti-emetic effect. Extremes of age;
Anti-emetic effect so useful in Pt. with
Propofol Potentiates GABA A Hypotension <17 YO; Egg/Soy allergy; Compromised
known post-op N&V
Apnoea airway
Laryngospasm Lipid soluble so quickly affects brain.
Potentiates GABA A (type of
Thiopental Myocardial Depression CI in airway
Lipid solubleobs.; ↓ BP;affects
so quickly ↓ Volume;
brain
barbituate) Porphyria
Arrythmia
Intravenous
Primary Adrenal insufficiency Causes less hypotension than propofol
Etomidate Potentiates GABA A Myoclonus or thiopental during induction (useful
N&V in haemodynamic instability)
Disorientation Doesn’t cx ↓ BP + has
Acts as dissociative bronchodilator
anaesthetic. Does
Ketamine Blocks NMDA receptors Hallucinations effect so is useful in trauma or
not cause drop in BP so useful in status
Anxiety asthmaticus
trauma
Propofol Infusion Syndrome
- Sx: Metabolic Acidosis; HF; Rhabdomyolysis; ↑ K+; Hepatomegaly; RF
- Cx: Propofol doses exceeding 4 mg/kg/hr
Eyelash Reflex
- Reflex: Good rule of thumb if eyelash reflex is absent then GA has taken effect
Emergency Medicine
Seán Keenan
2022
,American Society of Anaesthesiologists (ASA) Classification
American Society of Anaesthesiologists (ASA) Classification
ASA Classification Definition Examples
ASA I A normal healthy patient Healthy patient, non-smoking, no or minimal alcohol use
Mild Diseases only without substantive functional limitations. Examples include: Current
ASA II A patient with mild systemic disease smoker; Social alcohol drinker; Pregnancy; Obesity; Well-controlled DM; Well controlled
HTN; Mild lung disease
Substantive functional limitations; One or more moderate-severe diseases. Examples
include Poorly controlled DM; Morbid Obesity; Active Hepatitis; Alcohol dependence;
ASA III A patient with severe systemic disease
Implanted pacemaker; Moderately reduced RF; End-Stage Renal disease (undergoing
dialysis); Previous MI; Cerebrovascular events
Examples include recent MI (<3 months ago); Cerebrovasuclar accidents; Ongoing cardiac
A patient with severe systemic disease that is a
ASA IV ischaemia; Severe valve dysfunction; Severely reduced EF; Sepsis; DIC; ARD; End-Stage
constant threat to life
Renal Disease (not undergoing dialysis)
A moribund patient who is not expected to survive Examples include Ruptured abdominal/thoracic aneurysm; Massive trauma; Intracranial
ASA V
without the operation bleed with mass effect; Ischaemic bowel with cardiac pathology or organ dysfunction
A declared brain-dead patient whose organs are
ASA VI -
being removed for donor purposes
,Intravenous Access
Intravenous Access Cannulas
External Diameter Water Flow Rate
Colour Cannula Gauge Size Length (mm) Recommended Uses
(mm) (mL/min)
Orange 14G 2.1 mm 45 mm ~240 mL/min Trauma; Rapid blood transfusion; Surgery
Gray 16G 1.8 mm 45 mm ~180 mL/min Rapid fluid replacement; Trauma; Rapid blood transfusion
Green 18G 1.3 mm 32 mm ~90 mL/min Rapid fluid replacement; Trauma; Rapid blood transfusion
Pink 20G 1.1 mm 32 mm ~60 mL/min Most infusions; Rapid fluid replacement; Trauma; Routine blood transfusions
Blue 22G 0.9 mm 25 mm ~36 mL/min Most infusions; Neonate; Older adults; Routine blood transfusions
Yellow 24G 0.7 mm 19 mm ~20 mL/min Most infeusions; Neonate; Paediatric; Neonate or Paediatric blood transfusion
Peripheral Venous Cannula (PVC)
Description
- Use: Easy to insert with minimal morbidity - Limits: Unsuitable for vasoactives (inotropes) or
- Infusion: Wide lumen cannulae can allow for rapid irritant drugs in the long term
fluid flow rate - NB: Avoid cannulating foot in DM patients as may
- Infx: Can be rapidly identified and re-sited precipitate an ulcer and subsequent infx
Central Venous Cannula (CVC)
Description
- Use: More difficult to insert; USS usually required - Femoral: Easier and more easily managed if injury
- Coagulopathies: Bleed following iatrogenic injury - NB: Infx rate is higher
- IJV: Preferred route of access - Lumens: Multiple infusions but are narrow
Intraosseous Access
Description
- Use: Preferred in paediatric practice - Location: Dependent on age and preference
- NB: May also be used in adults - Humeral Head: Closer to heart to preferred in ALS
- Access: Marrow cavity + circulation - Proximal Tibia: Preferred in children
Tunnelled Lines
Description
- Use: Groshong + Hickman lines are popular for LT - Insertion: Usually inserted with USS guidance
administration of meds (e.g. chemotherapy) - Cuff: Anchors line; Require formal dissection
Peripherally Inserted Central Cannula (PICC) Line
Description
- Use: Peripherally situated for CVC access - NB: Less prone to major Cc than central lines
, General Anaesthetics
Anaesthetics
Route Drug MOA Adverse Effects Notes
Isoflurane Myocardial Depression Volatile liquid anaesthetics. Used for
Unknown. Combo of GABA A, Glycine
Desflurane Malignant Hyperthermia induction and maintenance of
and NDMA receptors
Sevoflurane Hepatotoxic (Halothane) anaesthesia
Inhaled
Risk of gas accumulation
Unknown. Combo of NMDA, nACh, Diffuse into gas-filled body
Nitrous Oxide E.g. CI in pneumothorax
5-HT3, GABAA and Glycine receptors compartments → Increased pressure
Headache and Nausea
Pain on injection Anti-emetic effect. Extremes of age;
Anti-emetic effect so useful in Pt. with
Propofol Potentiates GABA A Hypotension <17 YO; Egg/Soy allergy; Compromised
known post-op N&V
Apnoea airway
Laryngospasm Lipid soluble so quickly affects brain.
Potentiates GABA A (type of
Thiopental Myocardial Depression CI in airway
Lipid solubleobs.; ↓ BP;affects
so quickly ↓ Volume;
brain
barbituate) Porphyria
Arrythmia
Intravenous
Primary Adrenal insufficiency Causes less hypotension than propofol
Etomidate Potentiates GABA A Myoclonus or thiopental during induction (useful
N&V in haemodynamic instability)
Disorientation Doesn’t cx ↓ BP + has
Acts as dissociative bronchodilator
anaesthetic. Does
Ketamine Blocks NMDA receptors Hallucinations effect so is useful in trauma or
not cause drop in BP so useful in status
Anxiety asthmaticus
trauma
Propofol Infusion Syndrome
- Sx: Metabolic Acidosis; HF; Rhabdomyolysis; ↑ K+; Hepatomegaly; RF
- Cx: Propofol doses exceeding 4 mg/kg/hr
Eyelash Reflex
- Reflex: Good rule of thumb if eyelash reflex is absent then GA has taken effect
