Day 2: Equipment and Monitoring Flashcards
1
Q
types of airway support
A
- spontaneous ventilation
- mask ventilation
-supraglottic airways
-endotracheal airways - tracheotomy
2
Q
What material are endotracheal tubes (ETTs) typically made of?
A
Endotracheal tubes (ETTs) are typically made of polyvinyl chloride (PVC).
3
Q
How are ETTs inserted into the airway?
A
ETTs are placed through the vocal cords using a laryngoscope.
4
Q
What feature of ETTs helps seal off the airway?
A
ETTs have a cuff that can be inflated to seal off the airway.
5
Q
Do ETTs provide protection against aspiration?
A
ETTs provide protection against aspiration.
6
Q
Can patients be ventilated or breathe spontaneously with ETTs?
A
Patients can be ventilated or breathe spontaneously with ETTs.
7
Q
What is the common perception of ETTs in airway management?
A
ETTs are considered the gold standard of airway management.
8
Q
What distinguishes Armoured Endotracheal Tubes (ETTs) from standard ETTs?
A
Armoured Endotracheal Tubes (ETTs) have metal wiring embedded in the wall, making them more resistant to compression.
9
Q
In what situations are Armoured ETTs typically used?
A
They are used in non-standard positions such as
-prone,
-beach-chair,
-neurosurgery, and
-shoulder surgery.
10
Q
Are Armoured ETTs flexible or rigid?
A
Armoured ETTs are flexible, but their flexibility can make them more difficult to insert.
11
Q
What additional procedure are Armoured ETTs suitable for besides standard intubation?
A
Besides standard intubation, Armoured ETTs are also suitable for AWAKE NASAL FIBREOPTIC INTUBATION.
12
Q
What does RAE stand for in “RAE tubes”?
A
RAE stands for Ring-Adaire-Elwyn, named after the inventors.
13
Q
What distinguishes South-facing / Oral RAE tubes?
A
They are easy to insert with a predetermined depth but kink easily.
14
Q
In what types of surgeries are South-facing / Oral RAE tubes commonly used?
A
South-facing / Oral RAE tubes are used for
-surgery on the face,
-tonsillectomies, and
-eye surgery.
15
Q
What are the characteristics of North-facing / Nasal RAE tubes?
A
North-facing / Nasal RAE tubes are inserted through the nose and are more difficult to insert.
16
Q
For which types of surgeries are North-facing / Nasal RAE tubes typically used?
A
They are typically used for surgery in the
-mouth,
-jaw, or
-dental procedures.
17
Q
types of laryngoscope blades
A
-curved macintosh blade
-straight miller blade
18
Q
curved macintosh blade
A
commonest
tip placed in vallecula above epiglottis
19
Q
straight miller blade
A
less commonly used
tip placed underneath epiglottis
20
Q
indications for intubation
A
-procedures requiring immobilisation
- when artificial ventilation is required
- for securing the airway
21
Q
procedures requiring immbolisation
A
-thoracic and abdominal surgery
- microsurgery (e.g. retinal/ neurosurgery)
22
Q
when artificial ventilation is required
A
-long complex surgeries
-respiratory failure
23
Q
for securing the airway
A
- unfasted patients
-patients at risk of aspiration
-GCS<8 - non supine positions
- “shared airway” (ENT, eye, dental surgery)
24
Q
supraglottic airways
A
the LMA is the widely used SGA
25
What does LMA stand for?
LMA stands for Laryngeal Mask Airway.
26
Where do LMA devices sit?
LMAs sit on top of the glottis (vocal cords).
27
Can patients breathe spontaneously with an LMA in place?
Yes, patients can breathe spontaneously with an LMA in place.
28
Yes, patients can breathe spontaneously with an LMA in place.
LMAs do NOT offer reliable protection against aspiration.
29
In what situations are LMAs typically used?
LMAs are suitable for short procedures in fasted patients who do not require intubation.
They are also useful in emergencies as a backup or rescue airway when intubation or mask ventilation is not possible.
30
Difference between an ETT and an SGA
ETT passes through the glottis (vocal cords)
SGA is seated on top of glottis (cords)
31
other supraglottic airways
disposable LMA supreme
iGel
Proseal LMA
AMbu
32
The airway trolley: EMAILS
E- endotracheal tubes (different sizes)
M- masks (diffferent sizes), Magills forceps
A- Airways (oropharyngeal, nasopharyngeal)
I- introducers (gum elastic bougie, stylets)
L- laryngoscopes and LMAs
S- suction, syringe
33
What is another name for a gum elastic bougie?
Another name for a gum elastic bougie is an "introducer."
34
In what situations is a gum elastic bougie useful?
Gum elastic bougies are useful in difficult intubation scenarios.
35
Describe the structure of a gum elastic bougie.
A gum elastic bougie is a long, flexible device.
36
How is a gum elastic bougie used during intubation?
During intubation, the gum elastic bougie is passed through the glottis, and then the endotracheal tube (ETT) is advanced over it.
37
What is the purpose of a Yankauer suction tip?
The Yankauer suction tip is commonly used to suction oral and pharyngeal secretions.
38
How is the Yankauer suction tip connected to the suction system?
The Yankauer suction tip is connected to suction tubing, which is then connected to a collector that is linked to wall suction under negative pressure.
39
What is another name for OPA (Oropharyngeal Airways) ?
OPA is also known as Guedel airways
40
What is the function of an OPA?
An OPA assists in opening up the airway and relieving obstruction by preventing the tongue from covering the epiglottis and the back of the pharynx
41
use of an OPA
It can be used to assist spontaneously breathing patients or to improve mask ventilation
42
When is an OPA unsuitable?
Unsuitable for awake patients due to gag reflex.
43
How do nasopharyngeal airways compare to OPAs in terms of texture?
Nasopharyngeal airways are softer than OPAs.
44
What function do nasopharyngeal airways serve?
They prevent the tongue from obstructing the pharynx.
45
When might nasopharyngeal airways be used in patients recovering from anesthesia?
Nasopharyngeal airways are useful if OPAs fail and in patients at risk for sleep apnea during anesthesia recovery.
46
insertion of NSA
They should be inserted carefully with lubrication.
47
Why is it crucial to examine the patient's airway as a separate system?
Airway examination is essential regardless of the type of anesthesia planned.
48
What risks are associated with losing control of the airway?
Losing control of the airway can lead to fatal consequences.
49
risk under general anesthesia
Under general anesthesia, patients lose airway reflexes and may obstruct their airway or stop breathing.
50
When should the patient's airway be examined?
The patient's airway should always be examined to ensure proper management and prevent emergencies.
51
What is the primary difference between regional and general anesthesia?
Regional anesthesia targets specific body parts, while general anesthesia affects the entire body.
52
How does regional anesthesia work?
It involves blocking nerve signals to and from the targeted area, often resulting in limited or no sensation in that area.
53
What are the key characteristics of general anesthesia?
General anesthesia induces loss of consciousness and affects the entire body's functions, typically requiring mechanical ventilation to support breathing.
54
What are the four key scenarios in which patients are assessed for potential airway difficulty?
-Difficulty with bag-mask ventilation
-Difficulty with intubation
-Difficult rescue of the airway with a supraglottic airway if the above fail
-Difficulty with front-of-neck access (FONA) if all three of the above fail
55
Difficult mask ventilation : MOANS
M- mask seal problems (beards, tubes etc.)
O- obesity or obstruction
A- age extremes (elderly or very oyung)
N- no teeth (edentulous)
S- stiff lungs or snoring
56
Difficult intubation: LEMON
L: look externally
E- evaluate the 3-3-2
* 3 fingers thyromental distance
*3 fingers interincisal distance
* 2 fingers thyrohyoid distance
M- mallampati classification
O: obstruction
N: neck mobility
57
Difficult supraglottic RODS
R: restricted mouth opening
O: obstructions or morbid obesity
D: distorted or dysmoprhic anatomy
S: stiff lungs (e.g. bronchospasm)
58
Difficult FONA: SHORTHY
S- scars or surgery to the neck
H- haematomas (bleeding into the neck)
O- obesity or obstruction
R- radiotherapy to the neck
T- trauma or tumours of the anterior neck
Y- young patients
59
airway assessment: FACE
-Overt tumours
-Congenital syndromes (Trisomy 21, Pierre-Robin Sequence)
-Facial trauma
-Facial hair
60
airway assessment: MOUTH
-Assess the MOUTH OPENING
-Look for macroglossia
-Look for tumours, trauma, other masses
-The MALLAMPATI SCORE is a predictor of difficult intubation
-Dentition (to follow)
61
airway assessment: NECK
- first exclude C- spine injury
-Assess the LENGTH and THICKNESS of the neck
-RANGE OF MOVEMENT:
Extension and flexion
-The THYROMENTAL and STERNOMENTAL distances, if reduced, are predictors of difficult intubation
-Check whether the TRACHEA is central
62
the fours "D"s pf airway assessment
- disproportion
-distortion
-dysmobility
-dentition
63
disproportion
Macroglossia (big tongue)
Micrognathia (small chin)
High-arched palate
Bony abnormalities
Short thick neck
64
distortion
Airway trauma
Epiglottitis
Laryngeal tumours
65
dysmotility
Limited mouth opening
Fixed cervical spine / decreased extension
Cervical spine injury
-NEVER examine neck movement if a C-spine injury has not been excluded
-Be very careful in trauma patients
66
dentition
Issues with DENTITION can make laryngoscopy and intubation difficult:
Is the patient
-EDENTULOUS? (no teeth)
-Are there MISSING TEETH?
-Are there PROMINENT TEETH? (e.g. “buck teeth / prominent incisors”
-Are there LOOSE TEETH?
-Does the patient have specific DENTAL WORK that could be injured with laryngoscopy (e.g. caps, crowns)
67
bedside tests that predict difficult intubation
3-3-2
mallampati classification
neck mobility
68
mallampatic score
Class I = visualisation of the soft palate, fauces, whole uvula, anterior and posterior pillars
Class II = visualisation of the soft palate, fauces and most of the uvula
Class III = visualisation of the soft palate and only the base of the uvula
Class IV = only hard palate visible, soft palate is not visible at all
69
What is the common nickname for the anaesthesia machine?
Commonly called the "Boyle’s Machine"
70
What are the two principal functions of the anaesthesia machine?
Delivers gases to the patient (oxygen, medical air, nitrous oxide, and volatile anaesthetic agents)
Provides a means to manually ventilate the patient under positive pressure (via a connected bag and/or an integrated automatic ventilator)
71
basic parts of the machine
-gas supplies under pressure
-gas flow controls
-vaporisers
-the breathing circuit
-ventilation systems
72
gas supplies under pressure
piped medical gases from a central supply
backup cylinders on the machine
73
gas flow controls
flow meters or rotameters
74
vaporisers
convert volatile anaesthetic agents into gaseous form
75
the breathing circuit
connects machine to airway of patient (mask/ ETT/ SGA)
76
ventilation systems
-reservoir bag for manual ventilation
-automatic ventilator
77
How is oxygen stored in most hospitals?
Oxygen (O2) is stored in liquid form in giant external tanks, periodically filled, then converted to gaseous form and enters the central pipeline.
Hospitals often have a central backup manifold of large oxygen cylinders in case the tank supply is depleted.
78
What is the color code for oxygen piping?
What is the color code for oxygen piping?
79
How are oxygen cylinders identified?
Oxygen cylinders are black with white shoulders.
80
How is nitrous oxide commonly used in anesthesia?
Nitrous oxide (N2O) is commonly used as a carrier gas to augment anesthesia.
81
How is nitrous oxide stored in hospitals?
Since it cannot be stored in liquid form, hospitals keep a central manifold of large N2O cylinders which are piped to the theatre complex.
82
What is the color code for nitrous oxide cylinders and piping?
Nitrous oxide cylinders and piping are color-coded royal blue for easy identification.
83
black connection
clean medical air (21% oxygen in nitrogen)
84
backup oxygen
the backup oxygen cylinder behind the tubing should the wall oxygen fail or disconnect
85
How does gas enter the anesthesia machine?
Gas enters the anesthesia machine under high pressure, including oxygen (O2), nitrous oxide (N2O), and medical air.
86
How is the pressure of gas reduced to a safe level?
Valves step down the high pressure to a safe level.
87
What safety feature prevents the administration of nitrous oxide alone?
A safety interlock prevents N2O from being administered alone, ensuring that oxygen always opens as well.
88
How are gas flows and concentrations adjusted during anesthesia?
Gas Control:
Each gas has individual flow controls, which may be virtual or electronic in modern machines.
Gas Mixing:
Gas flows and concentrations are mixed as needed by the anesthetist, with oxygen typically mixed with either N2O or air during anesthesia.
89
What is the function of vaporisers in anesthesia?
Vaporisers convert volatile anaesthetics from liquid into gaseous form.
90
How are volatile anaesthetics delivered to the patient?
The gaseous form of anaesthetics is then delivered into the gas mixture administered to the patient.
91
How are vaporisers differentiated for specific volatile agents?
Each volatile agent has a specific vaporiser, which is color-coded for easy identification.
92
Why do vaporisers require special fillers?
Vaporisers require special fillers with specific shapes to prevent incorrect filling, ensuring patient safety.
93
commonly used volatiles
halothane: red
isoflurane- purple
secoflurane- yellow
desflurane- blue
94
What are vaporiser fillers used for?
Vaporiser fillers are used to safely and accurately fill vaporiser bottles with volatile anaesthetics.
95
What are the two types of vaporiser fillers?
They can be metal or plastic keyed fillers (top) or funnel-filler adapters (bottom).
96
How are vaporiser fillers specific to each agent?
Each filler is designed specifically for a particular volatile agent.
97
How are vaporiser fillers color-coded?
Vaporiser fillers are color-coded to match the same agent, ensuring correct identification and use.
98
What is the Circle System?
The Circle System is utilized on modern anaesthesia machines.
99
What components does the Circle System consist of?
It comprises tubing with unidirectional valves and a carbon dioxide absorption system.
100
How does gas flow within the Circle System?
Gas flows from the machine into the inspiratory limb towards the patient, while the patient exhales via the expiratory limb.
101
What is the purpose of the Circle System?
The Circle System facilitates the delivery of anaesthetic gases to the patient while efficiently removing carbon dioxide from the exhaled breath.
102
What is soda lime used for in the Circle System?
Soda lime granules absorb exhaled carbon dioxide in the Circle System.
103
What are the benefits of using soda lime?
Allows for the use of low gas flows, which is cost-effective.
104
How does soda lime prevent drying out of the patient's airway?
CO2 reacts with soda lime to produce heat and moisture, preventing the drying out of the patient's airway.
105
How can you tell when soda lime needs to be replaced?
Soda lime contains an indicator that changes color when it becomes exhausted, signaling the need for replacement.
106
What is the Ayre's T-Piece?
A lightweight breathing circuit used in paediatrics.
107
What is its ideal use case?
Ideal for induction in paediatric patients.
108
Is it valve-free, and how is ventilation controlled?
Valve-free design with an open reservoir bag that can be occluded for controlled (manual) ventilation.
109
What is required to wash out CO2 effectively?
Requires a minimum gas flow of 2-3 times the patient's minute ventilation (MV) for spontaneous breathing and 2 times MV for controlled (manual) ventilation to effectively wash out CO2.
110
What do HMEFs stand for?
HMEFs stands for Heat Moisture Exchange Filters.
111
What is their primary function?
Warm and humidify gases delivered to the patient.
112
How are they shaped, and how are they used?
How are they shaped, and how are they used?
113
Are they efficient at filtering bacteria?
Not necessarily efficient at filtering bacteria.
114
What is the primary purpose of the reservoir bag?
The reservoir bag is used for manual ventilation of the patient.
115
How is the reservoir bag used for manual ventilation?
It is used by closing an adjustable valve.
116
What function does the reservoir bag serve when the valve is fully open?
With the valve fully open, patients can breathe spontaneously, and the bag can be used to monitor respiratory efforts.
117
Can the reservoir bag provide positive end-expiratory pressure (PEEP)?
It can provide positive end-expiratory pressure (PEEP).
118
What additional function can the reservoir bag serve regarding circuit integrity?
The reservoir bag can be used to check the circuit for leaks.
119
What are self-inflating resuscitators also known as?
AmbuBag.
120
What distinguishes self-inflating resuscitators from other ventilation devices?
They are free-standing and self-inflating.
121
Are self-inflating resuscitators typically part of the anaesthetic machine?
They are not part of the anaesthetic machine but are essential equipment.
122
What is their primary purpose in the operating room?
Used as a backup ventilation device in case of machine failure or leaks.
123
Can patients breathe spontaneously with self-inflating resuscitators?
Yes, patients can also breathe spontaneously with these device
124
What is typically incorporated into most anaesthesia machines?
Most anaesthesia machines incorporate an automatic positive pressure ventilator.
125
What are the two general modes of ventilation used by ventilators?
Volume Control Ventilation (VCV) and Pressure Control Ventilation (PCV).
126
What adjustable settings does a ventilator typically have?
Tidal volume (if VCV), airway pressure (if PCV), respiratory rate, PEEP, and inspiratory/expiratory ratio.
127
What additional measurement capabilities do modern ventilators often include?
Many ventilators include a spirometer to measure the patient’s actual tidal volume and airway pressures, often with a graphical display.
128
Other important features on an anaesthesia machine
-Oxygen FLUSH if pressed, bypasses all other gas flow and gives high flow 100% oxygen
-Oxygen failure alarms
-Oxygen analysers
-”Pop-off” valves which release pressure if too high
129
examples of monitoring in anaesthesia
-monitors of the machine and equipment
- monitors of the patient
-clinical examination
130
monitors of the machine and equipment
-Ventilator pressures and volumes
-Gas supply pressures
-Oxygen concentration
-ETT cuff pressures
131
monitors of the patient
-Cardiovascular: ECG,BP
-Respiratory: Pulse oximeter, capnography, gas analysis
-Nerve stimulation monitoring
132
clinical examination
Don’t forget you as a doctor are a monitor as well!
When all else fails take the patient’s pulse…
133
machine monitors
-Gas supply pressures (piped gas and backup cylinders)
-Oxygen concentration (separate from the patient’s oxygen monitor)
This may be part of the ventilator monitors
-Breathing circuit pressure
-Battery and power supply
-Ventilator monitors
*Respiratory rate
*Spirometry: the airway pressures and volumes produced by the patient (whether during spontaneous or automatic ventilation)
134
ALL patients should have the following monitors attached as MINIMUM
ECG
Pulse oximetry (saturations)
Non-invasive blood pressure (NIBP)
Regardless of whether they are having general, regional or local anaesthesia
135
If under general, the following are also mandatory:
Capnography (end-tidal CO2)
Temperature (usually as an oral or nasal probe)
FiO2 (inspired oxygen concentration)
136
ECG
-Usually 3-lead
-For sicker / cardiac patients, a 5-lead array is available
-ECG information:
*Heart rate
*Heart rhythm
*ST segment analysis (ischaemia)
*Arrhythmia alarms
137
Pulse oximetry (“Sats monitor”)
-Measures the oxygen saturation of capillary haemoglobin,
-This correlates with arterial Hb saturation
-Uses absorption of red and infra-red light to calculate saturation
-Normal range 92–100%
-Non-invasive – attached to fingertips (also toes, earlobes)
-Measures pulse rate as well
-Portable pulse oximeters are widely available now
138
gas analysis
-Modern machines use a multi-gas analyser which analyses
*Capnography (CO2)
*Inspired and expired oxygen concentrations (FiO2 and FeO2)
*Inspired and expired anaesthetic gas concentrations (Fi/Fe AA)
--Volatiles and the gas N2O)
--The machine calculates the resultant MAC of the gas mixture (an indicator of depth of anaesthesia)
These are displayed as separate waveforms and/or numbers
139
capnography
-measures the patient's exhaled CO2
-essential monitor
- can be used to detect
140
capnography: measures the patient's exhaled CO2
Usually measured in kPa (mmHg in USA)
Also calculates respiratory rate
Normal range: 4.5–6.0 kPa
Does not give an indication of adequacy of oxygenation
141
capnography: essential monitor
Shows that gas exchange is taking place and that alveoli are both perfused and ventilated)
A continuous CO2 trace is one of the confirmatory signs of successful endotracheal intubation
142
capnography
Accumulation/rebreathing of CO2 in circuit / exhaustion of soda lime (Inspired CO2 should be zero)
Oesophageal intubation (no steady CO2)
Malignant hyperthermia (sudden, rapid, severe rise)
Pulmonary embolism (sudden loss of CO2)
Patient breathing spontaneously against ventilator
143
non- invasive blood pressure (NIBP)
Non-invasive: cuffs usually on upper arm
Correct size must be chosen
Set to automated cycles (in theatre, usually every 2.5 – 3 minutes)
For more precise real-time measurement, invasive arterial monitoring is used
144
arterial lines
Inserted into peripheral artery (typically radial)
Allows for continuous beat-to-beat accurate live blood pressure analysis
Allows for continuous blood sampling
Typically inserted via Seldinger technique using guidewire
145
The central venous line: venous access rather than a monitor
Inserted into the vena cava via internal jugular, subclavian or even femoral veins
May have multiple lumens (shown here are 2 lumens)
Require complete sterile technique
Used for administering potent / dangerous drugs like potassium, inotropes, vasodilators, as well as parenteral (IV) nutrition
Placed via Seldinger technique (needle finds vessel, guidewire inserted into vessel, needle withdrawn, catheter then fed to desired depth, guidewire removed, catheter sutured and dressed
Needs X ray confirmation; complications include bleeding, myocardial damage and sepsis. Often sited using ultrasound guidance.
146
other monitors
-Urine output (catheter)
-Oesophageal temperature monitors (nasal or oral placement)
-Endotracheal cuff pressure monitors
-Transoesophageal echocardiography
-Pulmonary arterial catheter–rarely used today
147
