2. Rapid Sequence Induction
Pulmonary aspiration of gastric contents
One of the most feared complications of anaesthesia
Reason for pulmonary aspiration of gastric contents
in the peri-operative period
General anaesthesia
Unconsciousness
No gag, laryngeal, cough reflexes
7. Rapid Sequence Induction
Decreasing the severity of aspiration pneumonitis
Decrease volume of gastric contents
Increase pH of gastric contents
Ensure there is no particulate matter in the stomach
8. Rapid Sequence Induction
Decreasing the severity of aspiration pneumonitis
Pre-operative management
Decrease volume and particulate matter
Fasting
NG tube (won’t fully empty stomach)
Metoclopramide
9. Rapid Sequence Induction
Decreasing the severity of aspiration pneumonitis
Pre-operative management
Increase pH
Na citrate 0.3 M 30 ml PO
10. Rapid Sequence Induction
Decreasing the severity of aspiration pneumonitis
Pre-operative management
Decrease volume and increase pH
Ranitidine 150 mg nocte and 2 h pre-op. PO
Proton pump inhibitor, e.g. omeprazole
11. Rapid Sequence Induction
Decreasing the severity of aspiration pneumonitis
Intra-operative management
Local anaesthesia
or
General anaesthesia with rapid sequence induction
12. Rapid Sequence Induction
Decreasing the severity of aspiration pneumonitis
Post-operative management
Extubate the trachea when the patient is fully
awake
13. Rapid Sequence Induction
Full stomach, risk of regurgitation
General categories
Abdominal disease
Trauma
Abdominal distension
(pregnancy, obesity, ascites)
Gastro-oesophageal reflux
(hiatus hernia or reflux symptoms)
Abdominal pain
Bowel obstruction
UGI bleeding
14. Rapid Sequence Induction
Other situations associated with an increased risk of
regurgitation and aspiration
Patients who have not been fasting or whose fasting
status is unknown
e.g.
Most emergency intubations in the Emergency
Dept., ICU and wards
15. Rapid Sequence Induction
Pregnancy
Cause of increased risk of regurgitation and
aspiration
Decreased LOS pressure
Effect of progesterone on smooth muscle
Mechanical effects of enlarging uterus
Increased intragastric pressure
Decreased gastro-oesophageal angle
Increased gastric acidity
Placental gastrin
16. Rapid Sequence Induction
Pregnancy
Cause of increased risk of regurgitation and
aspiration
Gastric emptying
Not delayed during pregnancy
Delayed during labour
Gastric stasis aggravated by:
Pain
Anxiety
Opioids (including subarachnoid and epidural
opioids)
17. Rapid Sequence Induction
Pregnancy
Duration of increased risk of regurgitation and
aspiration
16 weeks gestation to 48 h postpartum
or
Anytime if symptoms of gastro-oesophageal reflux
18. Rapid Sequence Induction
Rapid sequence induction
Classical
I will describe
Commonly used for caesarean section under GA
Less commonly used in other specialties
Modified
Commonly used
20. Rapid Sequence Induction
Key elements of rapid sequence induction
Fast-acting IV induction agent and succinylcholine
No other drugs
Pre-calculated doses without titration
Cricoid pressure
No ventilation with face mask before tracheal
intubation
21. Rapid Sequence Induction
Drugs given before tracheal intubation
Fast-acting IV induction agent
(acts in one arm-brain circulation time)
Propofol
or
Thiopental (available, now rarely used)
Succinycholine (suxamethonium) 1.5 mg/kg
Onset 30-60 s
Duration 4-6 minutes
No other drugs
23. Rapid Sequence Induction
Note:
The IV induction agent and succinylcholine are given
in precalculated doses without titration, i.e. they are
given in “rapid sequence”
Only these two drugs should be given so that if
intubation is impossible, the patient will resume
spontaneous breathing and wake up before hypoxia
or aspiration occurs
24. Rapid Sequence Induction
What’s the problem with giving precalculated doses
of only two drugs and no opiate?
31. Rapid Sequence Induction
Cricoid pressure
Mode of action
The cricoid cartilage is the only cartilaginous part
of the upper airway to be a complete ring
When cricoid pressure is applied, the hypopharynx
(laryngopharynx) is compressed between the
cricoid cartilage in front and the vertebrae (esp.
C6) and prevertebral muscles behind
33. Rapid Sequence Induction
Cricoid pressure
Mode of action
20 Newtons (2 kg) of cricoid pressure is probably
enough and 30 Newtons (3 kg) is more than
enough to prevent regurgitation into the pharynx
34. Rapid Sequence Induction
Cricoid pressure
Procedure
Locate the cricoid cartilage - the first cartilage
below the thyroid cartilage (Adam’s apple)
Using the dominant hand, place the index finger
and thumb on either side of the cricoid cartilage
(some use three fingers)
Normally, the assistant applies cricoid pressure
with his/her dominant hand, as this can be
maintained more accurately and for longer (3-5
min.)
35.
36. Rapid Sequence Induction
Cricoid pressure
Procedure
Apply counter pressure to the back of the neck if
there is a suspected cervical spine injury. This will
reduce movement of the cervical spine.
40. Rapid Sequence Induction
When the anaesthetist says you can
This is usually when a cuffed tracheal tube
protects the airway and the anaesthetist confirms
this with capnography
42. Rapid Sequence Induction
Cricoid pressure
Problems
Difficult to do it properly
May be difficult to identify cricoid cartilage
May be difficult to apply correct force in correct
direction to cricoid cartilage
? Ultrasound
43. Rapid Sequence Induction
Cricoid pressure
Problems
It may make airway management more difficult,
especially if too much force
Difficult mask ventilation
Difficult tracheal intubation
Difficult insertion of supraglottic airway
? Release
? Release
Release
47. Rapid Sequence Induction
Preoxygenation
Rationale
No ventilation with face mask before tracheal
intubation
Ventilation only after tracheal intubation
A longer period of apnoea than during routine
induction of anaesthesia
Adequate pre-oxygenation prevents oxygen
desaturation during this period of apnoea
49. Rapid Sequence Induction
Preoxygenation
Procedure
3-5 min. of tidal volume breathing
or
4-8 slow, vital capacity breaths
or
Until end-tidal O2 is at least 90%
The mask must have a seal on the face and the
reservoir bag must distend with each breath
51. Rapid Sequence Induction
One anaesthetist, two anaesthetic assistants
Anaesthetic assistant No. 1 applies cricoid pressure
Anaesthetic assistant No. 2 prepares airway
equipment and holds face mask
Anaesthetist injects drugs
When the drugs are injected, the anaesthetist holds
face mask
52. Rapid Sequence Induction
Anaesthetic assistant No. 3 performs manual in-line
stabilisation, if there is a possible cervical spine injury
(remove collar first)
54. Tracheal Intubation
Position of head and neck
“Sniffing position”
“Sniffing the morning air”
“Drinking a full pint of beer”
“Win with the chin”
Best position to win a running race, where the
chin wins the race
55. Tracheal Intubation
Position of head and neck
Flexion of lower cervical spine
35o neck flexion
Extension of atlanto-occipital joint
15o head extension
59. InternationalAnesthesia Research Society. Published by International Anesthesia Research Society. 8
Figure 7
Head and Neck Position for Direct Laryngoscopy.
El-Orbany,Mohammad;Woehlck, Harvey; Salem, M
Anesthesia & Analgesia. 113(1):103-109, July 2011.
DOI: 10.1213/ANE.0b013e31821c7e9c
Figure 7 . Some commercially available elevation pillows
for positioning obese patients before direct
laryngoscopy.A, Troop Elevation Pillow. B, Oxford Head
Elevating Laryngoscopy Pillow (HELP). C, Rapid Airway
Management Positioner (RAMP).
Inflatable
A Troop Elevation Pillow
B Oxford Head Elevating Laryngoscopy Pillow (HELP)
C Rapid Airway Management Positioner (RAMP)
63. Rapid Sequence Induction
Sequence of events
Check equipment
Draw up drugs
Attach monitors
Ensure good IV access
Place sucker and bougie under pillow
Switch on suction
Aspirate NG tube, if present
64. Rapid Sequence Induction
Sequence of events
Start preoxygenation
The anaesthetist should confirm that the assistant’s
fingers are correctly placed on the cricoid cartilage
and that it is tolerable to the patient
Give IV induction agent and succinylcholine
When the patient is unconscious, apply cricoid
pressure (30 N = 3 kg)
65. Rapid Sequence Induction
Sequence of events
Leave face mask in situ until the fasciculations have
stopped
Remove face mask
Perform laryngoscopy and insert ETT
Inflate cuff immediately, without titration
Ventilate via the ETT
Check capnograph for expired CO2
Auscultate chest bilaterally in midaxillary line and
over stomach
66. Rapid Sequence Induction
Sequence of events
Release cricoid pressure only when instructed to do
so by the anaesthetist
Check cuff pressure is 20-30 cm H2O
Start sevoflurane, give non-depolarising muscle
relaxant, e.g. rocuronium
If not caesarean section, give opiate
If caesarean section, give opiate after delivery
67. Rapid Sequence Induction
Modified Rapid Sequence Induction
Opiate, e.g. fentanyl
Wait for IV induction agent to work
Ventilation with face mask
Rocuronium 1-1.2 mg/kg
Onset 30-60 s (similar to succinylcholine)
Duration ≥ 60 min, up to 230 min, variable++
Rocuronium 0.6 mg/kg
Onset “1-2 min”, variable++
Duration 30-45 min, variable++