Basic exam 1_Lena Flashcards
to pass the exam (173 cards)
1
Q
what is the mallampatti ?
A
use to assess the oropharyngeal space. “PUSH”
the higher the number= the higher the for more difficult intubation. by itself is a poor predictor. its predictive power increase when we use it in conjunction of other airway exams.
2
Q
what is the tyroidmental distance?
A
Helps determine how readily the laryngeal axis will fall in line with the pharyngeal axis. 6.5 cm = no problem with laryngoscopy/ intubation
6 – 6.5 cm = difficult but possible laryngoscopy
< 6 cm = impossible laryngoscopy
>9 cm=the larynx assumes a caudal position. because the tongue is fixed at the hyoid bone, the Tonge moves posteriorly as well (caudally) these changes shift the glottis beyond the line of site.
3
Q
what is the mandibular protrusion test ?
A
“bulldog” assess the the function of the TMJ (condylar joint). class A,B,C (1,23)
4
Q
what is the Mandibulohyoid Distance?
A
The epiglottis arises from the thyroid and remains dorsal to the hyoid bone.
Therefore, the position of the hyoid bone marks the entrance to the larynx.
< 4cm intubation via DL may be impossible.
5
Q
what’s Atlanto Ocipital joint mobility test? and what conditions that impair AO mobility ?
A
it test the ability to place the patient in a sniffing position because its dependant on the AO mobility.
Degenerative joint disease, rheumatoid arthritis, ankylosis spondylitis, trauma, surgical fixation, Klippel-feil, Down syndrome, diabetes mellitus.
normal flexion and extension : 90-165 degrees
6
Q
what is the Laryngeal assessment technique?
A
Cornmack Lehan. Measures the view obtained during direct laryngoscopy.
1-4:
1. you can see everything
2. only posterior commissure of the glottic opening can be seen. you can’t see the anterior fissure
3. you can only see the epiglottis
4. you can only see the soft palate
7
Q
assessing for difficulty bag-mask ventilation?
A
M-> mask seal O-> obese A-> aged (loss of muscle tone) N-> no teeth S-> snore/stiffness (increased resistance or lack of compliance)
8
Q
assessing for LEMON: Difficult laryngoscopy?
A
Look externally (if it looks difficult, it probably is)
Evaluate 3-3-2 (Oral opening 3Fb, TMD 3FB, position of larynx relative to base of tongue 2FB)
Mallampatti
Obstruction
Neck mobility
9
Q
Ankylosis Spondylitis
A
is a form of arthritis that primarily affects the spine, although other joints can become involved. It causes inflammation of the spinal joints (vertebrae) that can lead to severe, chronic pain and discomfort
10
Q
importance of airway management: Three main causes of death following anesthesia as per ASA are:
A
Inadequate ventilation (38%) Esophageal intubation (18%) Difficult tracheal intubation (17%)
11
Q
what nerves innervate the nose ?
A
Innervated via opthalmic and maxillary divisions of the Trigeminal Nerve (CN V):
Nasal mucosa, anterior ethmoidal, nasopalatine, and sphenopalatine nerves
-Resistance is 2x that of mouth breathing
12
Q
Pharynx connects what cavities to the larynx and the esophagus?
A
oro and naso cavities. Divided into: Nasopharynx (Separated by soft palate) Oropharynx (Separated by epiglottis) Hypopharynx (extends from oropharynx to vocal cords)
13
Q
how many cartilages does the larynx have?
A
the adult larynx extend from C3-C6
Nine cartilages
thyroid, cricoid, epiglottic; arytenoid, corniculate, cuneiform
14
Q
the tracheal anatomy consists of
A
1st tracheal ring is anterior to C6 Trachea ends at the carina (level T5) Tracheal length approx. 15cm (adults) 16-20 C-shaped cartilages Cricoid cartilage
15
Q
Cricothyroid muscles
A
lengthen and stretch the vocal folds
16
Q
Intrinsic muscles
- Posterior cricoarytenoid muscles
- Lateral cricoarytenoid muscles
- Transverse arytenoid muscle
A
- abduct and externally rotate the arytenoid cartilages, resulting in abducted vocal cords
- adduct and internally rotate the arytenoid cartilages, which can result in adducted vocal folds
- adducts the arytenoid cartilages, resulting in adducted vocal cords
17
Q
Extrinsic muscles
A
Thyrohyoid muscles (attached to Hyoid)
Sternothyroid muscles
Inferior constrictor muscles
Digastric
4 Muscles attached to Hyoid: Stylohyoid (attached to Hyoid) Mylohyoid (attached to Hyoid) Geniohyoid (attached to Hyoid) Hyoglossus (attached to Hyoid)
18
Q
Sensory supply
A
Trigeminal nerve (V)
V1 ophthalmic
V2 maxillary
V3 mandibular
Glossopharyngeal nerve (IX)
Vagus nerve (X)
Superior laryngeal
Recurrent laryngeal
19
Q
Trigeminal Nerve (V) innervates?
A
Anterior ethmoidal nerve - V1
Opthalmic division
Anterior third of the septum and lateral wall
Sphenopalatine nerves - V2
Maxillary division
Posterior 2/3rds of the septum and lateral wall
Lingual nerve - V3
Mandibular division
20
Q
Glossopharyngeal Nerve (IX) innervates
A
Innervates Posterior 1/3 of the tongue Roof of the pharynx Tonsils Soft palate oropharynx vallecula anterior side of the epiglottis Motor fibers to the stylopharyngeal muscle
21
Q
Vagus Nerve (X) innervates
A
Innervates between epiglottis and vocal cords -Superior laryngeal nerve Internal laryngeal nerve (sensory) -External laryngeal nerve (motor) Motor to cricoid thyroid? muscle
22
Q
superior (external) innervates what sensory and motor?
A
Sensory: Anterior subglottic mucosa;
Motor: Crycothyroid muscle (adductor tensor; tensor of the vocal cords)
23
Q
Superior Laryngeal Nerve Internal Branch (sensory) innervates what sensory and motor?
A
Sensory: (from the posterior side of the epiglottis to the vocal cord)
Aryepiglottic folds; Arytenoids;
Epiglottis - tongue base; Supraglottic mucosa (Hypopharynx); Thyroepiglottic joint; Cricothyroid joint
Motor: NONE
24
Q
Recurrent laryngeal nerve
A
Innervates the larynx (below vocal cords the trachea)
Posterior cricoarytenoid muscles: abduct vocal cords
Lateral cricoarytenoid muscles: adduct vocal cords
25
Evaluation of the airway
Thyromental distance
Measure between the edge of the mandible and the thyroid notch: should be > 6 cm
Small distance limits alignment of oral & pharyngeal axes
Head and neck
Full extension to full flexion (AO axis at least 35o)
Side to side movement
Trachea midline
```
Other factors
Short neck vs. Long neck
Ability to prognath
Mouth opening
Dentition
```
26
Thyromental Distance ?
Ideally done with the neck fully extended. Can be done in-line
Helps determine how readily the laryngeal axis will fall in line with the pharyngeal axis.
6.5 cm = no problem with laryngoscopy/
intubation
6 – 6.5 cm = difficult but possible laryngoscopy
< 6 cm = impossible laryngoscopy
27
Medical HistoryPredictors of difficult airway
```
Joint disease
Acromegaly-high Gh after puberty
Thyroid or major neck surgeries
Tumors, known abnormal structures
Genetic anomalies
Epiglottitis
Previous problems in surgery
Diabetes
Pregnancy
Obesity
Pain issues
```
28
Neck Mobility
Ideally the neck should be able to flex by 25-300 & extend atlanto-occipital joint by 80°
2/3 reduction in mobility = difficult DL
```
Problems:
Cervical Spine Immobilization
Ankylosing Spondylitis-
Rheumatoid Arthritis
Halo fixation
```
29
what do I need to intubate?
Cuffed Endotracheal tubes
2 available sizes (Not necessarily open!)
Laryngoscope blades & handles
Make sure working properly lights, bulbs, etc.
Face mask of adequate fit S, M, L sizes
-Back up: AMBU BAG
Face strap
Suction, Suction, Suction!!!
Machine check ability to deliver (+) pressure
Laryngeal mask airways available
Nasal and oral airways
Tongue blade
Difficult airway cart
Know the location & contents
30
face mask
Face mask
Ventilate the anesthetized patient
Create a tight seal with patient’s face for effective ventilation
Eyes = corneal abrasions
Deflation of breathing bag indicates leakage (CHECK YOUR PATIENT)
High breathing circuit pressures without chest movement indicate obstruction of the airway
Limit ventilation pressures to <20cm H20
31
oral and nasal airways ?
Used to create an air passage in the anesthetized patient after loss of muscle tone
Oral airways: 3 sizes for adults (80, 90, 100mm)
Nasal airways: several sizes, estimate length from nares to the ear meatus
Nasal airways are tolerated better by the lightly anesthetized patient
32
What are some contraindications to nasal airway use?
Anticoagulation, facial trauma, epistaxis contraindications for nasal airway
33
Laryngeal Mask airway
Inserted in the hypopharynx
Inflate to create a low pressure seal at entrance of larynx
LMA protects the larynx from pharyngeal secretions only
Ideal for short cases
Not a definitive airway – supraglottic device
No aspiration protection
May use Proseal LMA if concerned about gastric contents
34
what is the importance BMV?
Foundation and cornerstone of airway management
BMV is a SKILL just as much as Intubation is a SKILL
Proper technique essential for success
35
what are the steps of airway support during indiction?
Asure ability to bag-mask ventilate prior administering muscle relaxant
Keep the airway open – sniffing position - jaw trust, insert correct fitting nasal or oral airway
Keep the APL pressure LESS THAN 20 cmH2O
Once depth of anesthesia assured – proceed with airway instrumentation
36
what to remember while bag masking someone:
AVOID:
-Pressure on soft tissue vs the jaw bone
- Pressing down on the face without proper lifting of jaw bone
- Eyes, eyes, eyes
37
Anesthesia machine check out steps?
Anesthesia machine: Checkout should be completed EVERY MORNING PRIOR TO FIRST CASE OF THE DAY
-Verification: O2 failure alarms, cylinder pressures and HIGH/LOW pressure checks
- Vaporizers: FILLED prior to the start of the day
-Circuit checks: Prior to the start of each case (I.E.-IN BETWEEN CASES)
-ETCO2: CONNECTED prior to START of each case
-Soda lime absorbers: Attached and DO NOT NEED
REPLACING
38
max weight for standard OR bed ?
Know patient’s weight (standard OR table not equipped > 350 lbs.)
39
drugs should be labeled with what info?
```
Drug name
Drug dose
Date
Time
Provider initials
```
40
key player of the laryngospasms reflex?
cricothyroid muscle
41
The Left recurrent laryngeal nerve courses underneath the aortic arch before what ?
before it ascends to the trachea towards the larynx . causes. of Left recurrent laryngeal injury includes PDA ligation or left atrial enlargement d/t mitral stenosis .
42
what are the 4 nerves that innervate the airway ?
trigeminal n., glossopharyngeal n., superior laryngeal n. (external and internal), and recurrent laryngeal n.
43
what are the 3 keys airway blocks?
glossopharyngeal block, superior laryngeal block, transtracheal block ,
44
what is the most narrowest part of the pediatric airway?
```
2 answers: in an anesthetized child
vocal cords (dynamic) it can be stretched .
cricoid ring (fixed) cannot be stretched but it can become more narrow due to edema
```
45
what is the most narrow part of the airway for an adult?
the vocal cords
46
what is the Laryngospasm or Larson notch ?
is the sustained and involuntary contracture of the laryngeal musculature which causes the inability to ventilate
47
Laryngospasm pathway:
Afferent limb: Superior laryngeal n. (internal branch)
efferent limb: superior. laryngeal n. (external branch) & recurrent laryngeal n.
tensing the vocal cords: cricothyroid
adducting the vocal cords: lateral cricoarytenoid and thyroidarytenoid
48
what breaks laryngospasms?
hypercapnia and hypoxemia naturally. however we do not wait, administer 100% O2, remove noxious stimulation, deepen anesthesia, Cpap 15-20 cmH2o while giving maneuvers to open airway like head extension, chin lift and lards maneuver), give succ (for children <5 yo add atropine as well)
49
Larson notch maneuver
Placing fingers behind the earlobe and pressing firmly towards the skull. This accomplishes 2 things:
1. displaces the. mandible anteriorly in order to open airway
2. it often breaks the spasm by causing the patient sigh
pressure should be applied for 3-5 secs and then rest for 5-10 sec. repeat until spasm is gone.
landmars:
posterior: mastoid process
superior: skull base
anterior: rams of mandible
50
what is the Valsalva maneuver
it is when exhalation occurs while the glottis is closed. risks:
- increase thoracic pressure
- ^ brain pressure.
- ^ abdomen
51
what is muller's maneuver?
its inhalation against a. closed glottis.
risks:
- subatmospheric pressure in thorax --> negative pressure--> pulmonary edema
52
Tensor palatine muscle relaxation will most likely cause airway obstruction at which level ?
soft palate
- the relaxation of genioglossus would cause relaxation of tongue
- relaxation of the hyoid muscles would. cause epiglottis to relax
53
what's is the primary cause of upper airway obstruction?
tensor palatine and genioglosso muscle relaxation
54
where does the lower airway begin?
at the trachea and ends at the alveoli
55
Npo status hours
2- clear liquids
4- breast milk
6- regular milk, infant formula, solid foods
8- fried food
- ingestion of clear liquids 2 hrs prior procedure reduces gastric content and increases gastric pH reducing the risk for Mendelson syndrome
4 hours for neonates(infant formula)
56
what is the Mendelson syndrome?
Mendelson syndrome or peptic pneumonia refers to acute chemical pneumonitis caused by the aspiration of stomach contents in patients under general anesthesia.
gastric ph <2.5 gastric ph >25ml
57
when and how is rapid sequence induction done?
when a patient has a full stomach or other risk factors for inspiration .the patient is not ventilated and the esophagus is compressed by compressing the cricothyroid cartilage . pressure is applied before the patient losses LOC and maintained until trachea intubation is achieved.
pressure before LOC= 2kg
pressure after LOC= 4kg
not a benign procedure. complications include:
airway obstruction, esophageal rupture if patient is actively vomiting . look at work book for more complications
58
cervical spine anomalies include?
goldenhar, kipple fail, trisomy 21
59
what are the two main causes of facial edema? treatment include?
caused by ACE like enalaprilat or hederitary angioedema (C1 esterase deficiency)
tx: ACE--> epi, antihistamine, steroids just like an anaphylaxis reaction
C1 estarase deficiency--> C1 estarase concengtrate or FFP
60
what is Ludwig angina and how would you secure the airway?
is caused by a bacteria that causes cellulitis on the roof of the mouth. this inflammation and edema compresses the submandibular, sublingual and submaxillary spaces. the most significant concern is posterior displacement of the tongue resulting in complete subglottic airway obstruction.
awake nasal intubation or awake tracheostomy.
61
what is the optimal position for tracheal intubation?
AO joint extended and cervical flexion
62
position for obese?
HELP . Head Elevated Laryngoscopy Position.
sternum aligned with external auditory meatus . this is don't by playing blankets or cushion underneath head and uppertorso
63
which tube uses low volume high pressure cuff?
red rubber tube and silicone tube of the fasttrach. cannot measure pressure of cuff
64
what is the Murphys eye for?
to provide an alternative pathway for air movement in case the tip of the ETT becomes occluded or abut
65
what is the Murphys law?
fiberoptic scope, forceps or tubes changers can get stuck in the Murphys eye!
66
what is the proseal LMA?
its a double lumen LMA, that features:
-a gastric tube (second lumen) for easy gastric decompression
-larger mask
-bite block
compared to the LMA classic, benefits include:
better seal, max pressure for ppv <30 cm H2O for classic is <20cmH2O
LMA supreme is the disposable version
67
LMA fast track
its an intubating LMA
not suitable for MRI (metal handle)
LMA C-Trach , very similar to Fast track but includes camera.
ps. LMA flexible is also not suitable for MRI because is wired reinforced.
68
the tendency of airway device placement to activate the SNS (1 through 4) 1 is the most
1. combitube
2. DVL
3. fiberoptic intubation
4. LMA
69
What is a combitube?
A double lumen device, that is placed blindly in the hypopharynx; it provides secured airway in a patient with full stomach. additionally it doesn't require head extension so patients with klippel feil syndrome are okay . contraindications include: prolonged used (>2-3 hrs), esophageal disease ( Zenkeir's diverticulum), ingestion of cautic substances (causes burns) ..
combitube is oder than the king. the combiner's tube has two inflation ports, two ventilation ports and cannot insert NGT)
70
regarding the operation of the flexible fiberoptic bronchoscope :
-pushing the lever down points the tip up.
-the non-dominant hand control the level ..
its also the gold standard for managing a difficult airway.
-used for indirect laryngoscopy in awake or asleep patients.
71
contraindication for fiberoptic bronchoscopy
| ?
- limited time
- secretions not received by suction or antisialagogue
- hemorrhage that impairs visualization
- uncooperative patient (for awake patient)
- local anesthetic allergy (for awake patient)
72
when do you use an eschman introducer?
for a grade of 3 or 2 b on the Cormack-lehan grading scale. feeling the clicks of the tracheal should confirm placement if not then look for the "hold up" sign.
73
when do you use the lighted stylet ?
blind intubation technique is used for :
small mouth opening, bleeding, less stimulating than direct laryngoscope, less neck mobility, Pierre robin syndrome, burns
74
unlike the double lumen endotracheal tube, the bronchial blocker cannot:
- prevent contamination from the contralateral lung infection
- provide ventilation to isolated lung
- be used to suction secretion from isolated lung
bronchial blocker is used for lung separation and single lung ventilation. the lung on the opposite Side is ventilated .
75
what's retrograde intubation ?
its a blind procedure in which tracheal intubation is introduced by passing the endotracheal tube through a wire. introduced through the cricothyroid membrane
76
what is the transtracheal jet ventilation intubation?
its a percutaneous that requires a high pressure oxygen source. upper airway obstruction can block exhalation (risk for barotrauma)
77
pros and cons for deep extubation include?
PROs:
decrease CV and SNS stimulation, (which is desirable in patients with CAD) and decrease coughing and airway irritation (desired for asthma patients)
CONs:
ineffective airway reflexes, increased risk of airway obstruction (caution with sleep apnea), increased risk for aspiration, (coughing with Parkinson's disease)
78
how do you prevent complications with the awake patient?
CV and SNS stimulation: beta blockers, calcium channel blockers, and vasodilators
Coughing: lidocaine or opioids
79
what is the most common device used to manage extubation of a difficult airway?
airway exchanger catheter. it can stay in place for up to 72 hrs
80
upper airway dilator muscles do what?
1. tensor palatine
2. genioglossus
3. Hyoid muscles
1. open nasopharynx
2. opens oropharynx
3. opens hypopharynx
these muscles maintain a patent airway. loss of the muscle control can cause an obstruction (anesthesia , sedation, OSA)
81
what are the 4 anesthesia techniques?
general anesthesia, monitored anesthesia care, regional anesthetic (spinal, epidural), peripheral nerve block
82
what are some Surgical considerations?
Site
Positioning
Duration
83
what are some post-operative planning?
Discharge home, hospital admission, ICU admission
84
what does general anesthesia consist of?
Inhibition of sensory, motor, and sympathetic nerve transmission at the level of the brain
Reversible unconsciousness and lack of sensation
Immobility and muscle relaxation
Loss of voluntary reflexes
“Drug-induced loss of consciousness during which patients are not arousable, even by painful stimuli”
May be initiated/maintained using various methods:
IV bolus of drugs that produce unconsciousness
Mask induction
Inhalation of a volatile anesthetic
Spontaneous ventilation maintained
85
how do you support airway during general anesthesia?
Mask ventilation
Laryngeal mask airway (LMA)
Endotracheal intubation (GETA)
(-Laryngoscopy, -Fiberoptic intubation,-Intubating laryngeal mask airway)
86
inhalation agents (MAC and OIL:GAS) for N2O, desflurane, sevoflurane, enflurane, isoflurane, halothane, Methoxuflurane
MAC: Nitrous oxide (104) Desflurane (6.6), Sevoflurane (2%), Enflurane(1.7), Isoflurane (1.2), Halothane (0.75), Methoxuflurane (0.16).
Oil:Gas: N2O (1.4) Desflurane(19), Sevoflurane (51), Enflurane(98), Isoflurane (98), Halothane(224), Methoxuflurane (960)
87
the potency of an anesthetic increases as blank increases?
liposolubility increases
88
what are the Inhalational agents: Mechanism of action?
Interaction with protein receptors throughout the nervous system
Volatile agents preferentially potentiate GABAA and inhibit glutamate receptors
Nitrous oxide inhibits N-methyl-D-aspartate channels
***Uptake/removal of inhalation agents from the body depends on alveolar concentration of the agent and its uptake from the alveoli by the pulmonary circulation
89
what's is preoxygenation?
The process of replacing nitrogen in the lungs with oxygen
Allows for a longer duration of time before hemoglobin desaturation occurs in the apneic patient
Increases the safety margin between onset of apnea and resuming ventilation after the patient’s airway is secured
***Especially important in patients who will not be “masked” after induction of anesthesia
Like who?
RSI
90
the Uptake/removal of inhalation agents from the body depends on?
on alveolar concentration of the agent and its uptake from the alveoli by the pulmonary circulation
91
what are the phases of general anesthesia ?
Induction, Maintenance, Recovery
92
what is the induction phase of anesthesia?
This level encompasses the administration of preoperative medications, adjunctive drugs to anesthesia, and the anesthetics required for surgery
93
what is the maintenance phase of anesthesia?
This level begins when the patient has achieved a depth of anesthesia sufficient to allow the surgery to begin and ends upon the completion of the surgical procedure
94
what is the Recovery phase of anesthesia?
The recovery phase begins with the termination of the surgical procedure and continues throughout the postoperative recovery period until the patient is fully responsive to his or her environment
95
what are the Guedel’s Planes of Anesthesia?
Stage 1
This stage is characterized by the development of analgesia or a reduced sensation to pain
Stage II
This stage begins with unconsciousness and is associated with involuntary movement and excitement
Stage III
This is the stage where general surgery is performed.
It is divided into 4 planes that are based upon eye movement, depth of respiration, and muscle relaxation
Stage IV
This stage is characterized by respiratory or medullary paralysis
96
Maintenance of General Anesthesia
***Combination of drugs to provide amnesia, analgesia, muscle relaxation, control SNS responses
97
combination of drugs to maintain GA?
Nitrous oxide/oxygen +volatile agent
Nitrous oxide/O2 + IV anesthetic by continuous infusion (TIVA)
Above techniques plus narcotics and neuromuscular blocking agents when indicated
98
what is Rapid Sequence Induction?
Rapid onset of unconsciousness and muscle paralysis followed by rapid instrumentation of the airway
Goal:
Gain control of the airway rapidly after the ablation of protective reflexes
Decrease the risk of pulmonary aspiration (full stomach, incompetent LES)
99
how do you perform Rapid Sequence Induction?
Pre-oxygenate your patient!
**Have someone apply proper cricoid pressure at the BEGINNING of IV induction
Induce your patient with your IV anesthetic of choice
**DO NOT ventilate patient
Immediately give 1-1.5 mg/kg IV succinylcholine
**Intubate and CONFIRM ETT placement
**Once ETT placement has been CONFIRMED cricoid pressure is released
100
what are the indications for RSI?
Patients with full stomach
****Patient’s with bowel obstruction
Poorly controlled GERD
Diabetic gastroparesis
Pregnancy
Unknown NPO status
101
who is RSI not good for?
Patients who are actively vomiting
Those with cervical spine fractures
Patients with laryngeal fractures
102
what does the evidence say about cricoid pressure?
****It remains controversial
Some studies have shown that it actually decreases LES tone
MRI studies have shown varying images following cricoid
Literature has shown that it may worsen visualization during laryngoscopy Too much compression or improper application of cricoid pressure
103
does LMAO protect again aspiration?
Does not protect against aspiration of gastric contents
Low incidence of aspiration when used in patients at low risk
Ideal for short cases (2-3 hours max)
Designed initially for spontaneous ventilation
Safe use with positive pressure ventilation
Limit Tidal Volumes (TV) < 8ml/Kg
Maintain airway pressure <20cm H2O
Remove LMA
Pt deeply anesthetized/awake with intact reflexes
104
what are some LMA contraindications?
```
# 1 High risk for gastric content aspiration
Full stomach
Hiatal hernia with significant GERD
Morbid obesity
Intestinal obstruction
Delayed gastric emptying
```
105
what is the fasttrach LMA?
Designed to facilitate tracheal intubation through rigid tube
Stainless steel tube shaped to follow curvature of the soft/hard palate during insertion
Designed to be used with silicone ETT and introducer
7.0 - 8.0 ID (cuffed)
Stabilization of ETT is necessary to avoid extubation of the trachea
106
what are some supraglottic airways ?
King LT/COBRA, AirQ LMA
107
what is the sniffing position?
Sniffing position: alignment of the oral, pharyngeal and laryngeal axes
Pharyngeal and laryngeal axes: aligned by elevating the patient’s head (8-10cm)
Head extension at the atlanto-occipital joint aligns oral opening with the glottis (oral axis)
108
Oral tracheal intubation technique
Patient’s mouth is widely open
The laryngoscope is inserted to the right side of the mouth
Avoid incisors and sweep tongue to the left
Handle is raised towards the ceiling to lift the mandible
These maneuver should expose vocal cords
109
what's the Nasotracheal intubation technique?
Nasotracheal intubation:
Nostril pre-treated with a vasoconstrictor
A well lubricated ETT inserted through nostril
Cephalad traction of ETT as it advances through the floor of the nasal passages
Laryngoscopy will expose the pharynx and the vocal cords (Macintosh blade for better visualization)
110
what are the confirmation of ETT placement?
Persistent detection of CO2 by capnography
Auscultation of the chest and epigastrium
Visualization of ETT passing through cords
Thoracic movements (rise and fall)
Condensation of water vapor in the ETT
Palpation of cuff over the sternal notch during compression of pilot balloon
111
what are the Physiological responses to intubation?
Vagal stimulation during laryngoscopy
Bradycardia****
SNS stimulation
Systemic hypertension
Tachycardia
Cardiac dysrhythmias (light anesthesia)- PVCs
Increased intracranial and intraocular pressures
112
what are the Complications of tracheal intubation?
```
Cuff perforation
*Esophageal intubation
Endobronchial intubation
Cardiac dysrhythmias
Myocardial ischemia
Aspiration of gastric contents
Gastric distention
Airway trauma: tooth damage, lip or tongue lacerations, sore throat
Mucosal lacerations
Dislocated mandible
```
113
what are the criteria for awake extubation?
Criteria:
Pt awake & following commands
Intact gag reflex
Sustained head lift >5 seconds (resolution of neuromuscular block)
Oropharynx/hypopharynx free of secretions/blood-suction before patient wakes up !!
Return of spontaneous ventilations
TV >6cc/kg, negative inspiratory effort >20 cm H20
114
criteria of deep extubation?
Extubation before the return of airway reflexes
Contraindications: difficult intubation/mask ventilation, risk of aspiration (GERD,) airway edema, ↑ airway irritability
115
complications ofr trachea extubation?
```
Gastric aspiration
Sore throat
Laryngitis
Vocal cord paralysis
Laryngospasm
Laryngeal ischemia (high cuff pressures)
```
116
what are Laryngospasm?
Involuntary spasm of the laryngeal musculature
May result in complete airway occlusion and inability to ventilate
Caused by sensory stimulation of the superior laryngeal nerve*****
Secretions
Foreign matter (gastric contents)
May occur during induction or emergence from general anesthesia
Most common with desflurane
117
what are examples of The Difficult Airway?
```
Mallampati Class III or IV
Long upper incisors
Prominent overbite
Unable to prognanth jaw
Mental distance
mental distance < 6cm
Short and or thick neck
Limited ROM of head or neck
```
118
what is the definition of a difficult airway ?
Definition of a failed airway
Failure to maintain oxygen saturation >90%
Attempts at DL x3
Key to success
Call for help EARLY!!!
Anticipate the needs of your patient with early recognition of difficulty
119
what are some difficult intubation conditions?
trisomy 21, Pierre Robin, Treacher Collis, Cervical spine injuries, epiglottis, scleroderma (tighten connective tissue), radiation therapy, obesity, trauma, airway edema/trauma
120
what do you do if you have trouble ventilating?
```
Two person mask ventilation (Jaw thrust)
Oral & nasopharyngeal airways
Laryngeal mask airway (LMA)
Esophageal tracheal Combitube/KING Tube
Transtracheal jet ventilation
Rigid ventilating bronchoscope
Invasive airway access (cricothyrotomy)
```
121
what do two when you're having difficult intubating?
```
Awake intubation
Alternative laryngoscope blades
Blind intubation (oral/nasal)
Fiberoptic intubation (FOB)
Intubating stylet (Cook, gum bougie)
LMA as an intubating conduit (Fastrach LMA)
Light wand (light stylet?)
Retrograde wire intubation
Invasive surgical airway (cricothyroidotomy)
```
122
what's the The Difficult Airway Algorithm?
*****Anticipated difficult airway:
Awake :
```
Proper preparation, then awake intubation choices:
Glidescope
Fiberoptic Guided
Direct laryngoscopy
Retrograde Wire
Blind Nasal
Light Wand
Awake Tracheostomy
```
Under general anesthesia:
Difficult Airway under general anesthesia (+/-paralysis):
If unplanned, call for help EARLY!!
Maintain spontaneous ventilation if possible
If no spontaneous ventilation: can you mask ventilate?
If YES = GOOD
If NOT SO MUCH:
Reposition
Insert oral and/or nasal airways
Jaw thrust (2-handed/2-person technique)
*Cannot Intubate, Can Ventilate:
```
Consider other intubation choices:
LMA as ETT conduit (Air-Q, Fast-track LMA)
Glidescope
Fiberoptic intubation
Blind Nasal
Retrograde Wire
```
Consider providing GA via mask airway
123
Cannot Intubate, Cannot Ventilate:
Attempt LMA
Consider awakening the patient
Emergency non-invasive airway ventilation
Combitube, KING tube, rigid bronchoscope, transtracheal jet ventilation
Emergency Surgical Airway
Percutaneous tracheostomy or cricothyrotomy
124
what is a normal minute ventilation?
normal low 4 - normal high 8
125
RODS – Difficult supraglottic device
Restricted mouth opening
Obstruction in upper airway
Disrupted or distorted airway
Stiff lungs or c-spine
126
SHORT – Difficult cricothyrotomy or surgical airway
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Surgery/disrupted airway
Hematoma or infection
Obese or access problem
Radiation
Tumor
```
127
what are the steps of anesthetic induction?
Pre oxygenation – De-nitrogenation for 5 min or 4-5 full tidal volume breaths with a tight seal mask prior each anesthetic induction!
FGF O2 at 10 – 12L/min
Sustains O2 saturation >90% during apnea for apx 6 min in healthy individuals
128
what are the take home points?
Oxygenation is more important than intubation
Pre-oxygenate all patients
Several small abnormalities may add up to a difficult airway
Always have a back up plan
Always assure BMV before muscle relaxation
Gain confidence and skill with various approaches
129
what is more important? oxygenation or intubation??
oxygenation
130
do we preoxygenate all patients?
yes
131
will several small abnormalities add up to a difficult airway?
yes
132
what step is important before muscle relaxation?
assure that BMV can be done
133
What bone is the larynx supported by?
the hyoid
134
what is flow equals to?
flow=volume/time.
Units: Liters per minute (L/min.)
Delivery of ventilation (including all pressures and volumes) is **controlled by the adjustments in flow.**
its how much a volume flows through time
135
what is resistance?
Airway resistance: The pressure difference which drives flow divided by the volumetric rate of flow.
Resistance = Change in Pressure/Flow
The driving pressure difference -->gradient between "outside" pressure and "inside" pressure (Ex: ventilated patient, the inspiratory pressure and the alveolar pressure)
Total sum of resistance in the "patient circuit" --> tubes connecting the patient to the ventilator, to the bronchi, the chest wall, the lung parenchyma, the distended abdomen... This is the net product of all these factors
136
**what is the relationship of flow and volume?
Volume = Flow X Time
Basic bellows system where **the flow rate is fixed and where the volume control is done by adjusting the time
137
**The relationship of flow and Pressure?
Pressure=Flow X Resistance
Resistance the endotracheal tube, the patient’s own airway, the chest wall, and the lung itself against being distended (the reverse of compliance)
138
what's Compliance?
Compliance = Volume/change in pressure
Compliance in this setting is the total lung compliance (i.e. change in volume divided by change in pleural pressure)
Compliance = Flow X Time/change in pressure
One can calculate compliance by dividing the tidal volume by the difference between PEEP and plateau pressure
With PEEP of 10, with a plateau pressure of 30 and a tidal volume of 400ml, the patient has a compliance of 400 / (30-10), which is 20ml/cm
139
The anesthesia provider can control blank
the flow, time, volume and pressure on a ventilator
140
what's composed of the ventilatory cycle?
1. Inspiration
2. Transition from inspiration to expiration
3. Expiration (passive phase)
4. Transition from expiration to inspiration
141
what type of ventilation occurs with **negative pressure?
spontaneous.
Periodic exchange of alveolar gas with fresh gas from upper airway re-oxygenates desaturated blood and eliminates CO2
Alveolar pressure is always higher than intrapleural pressure
P transpulmonary = (P alveolar – P intrapleural)
142
in spontaneous ventilation, what happens At the end of expiration?
Alveolar pressure is 0 (or atmospheric 760 mm Hg)
Intrapleural pressure is normally -5 cm H20
Diaphragmatic relaxation
143
during spontaneous ventilation, what happens During Inspiration?
Intrapleural pressure **-8 cm H20
Alveolar pressure **-3 cm H20
Increased alveolar upper airway gradient
Gas flows into the lungs and alveoli
144
during spontaneous ventilation, why happens at the end of inspiration ?
At the end of inspiration
Alveolar pressure equalizes with atmospheric pressure (0 cm H20)
Intrapleural pressure remains -8 mm Hg
Gas inflow stops
The higher alveolar/intrapleural pressure gradient sustains lung expansion
145
what are the indictions for mechanical intubation?
indications**
Treatment of respiratory/ventilatory failure (V/Q mismatch)
(Reduction in work of breathing
Correction of acid-base imbalances
Ability to control respiratory dynamics via secure airway)
Reduce work of breathing (WOB)
CHF
Neurological/cardiac impairments
```
**Anesthesia for surgery
Airway protection
Decrease aspiration risk
Maintain adequate alveolar ventilation
Facilitate surgical procedure performance
```
146
how do ventilators work?
Function by creating a pressure gradient between proximal airway and the alveoli
2 kinds of ventilators:
Negative pressure (in thorax) – “iron lung”
**Positive pressure (in upper airway)- via ETT/tracheostomy
Pressure higher than atmospheric pressure
147
all pressure above atmospheric pressure is called?
positive pressure. 760 mmhg
148
what contributes mechanical ventilator settings?
```
Mode
Respiratory Rate (RR)
Tidal Volume (VT)
Minute Ventilation (MV = TV x RR)
Pressure
FiO2- indicates the amount of oxygen the ventilator delivers, expressed as a percentage or a number between zero and one
PEEP (Positive end-expiratory pressure)
PIP (Peak inspiratory pressure)
I:E ratio (Inspiratory to expiratory ratio)
Flow rate (L/min)
Flow pattern
Alarms
```
149
what is minute ventilation?
The air an individual breathes in one minute
MV is the primary determinant of what?
**VT -Air volume breathed in during a single inhalation or
exhalation from the lungs at rest
MV 8-10 ml/kg
**VD – (dead space) Air remaining in the airways that does not participate in gas exchange
Accounts for about 1/3 of VT
***MV= VT x RR*
150
MV is the primary determinant of what?
**VT -Air volume breathed in during a single inhalation or
exhalation from the lungs at rest
MV 8-10 ml/kg
**VD – (dead space) Air remaining in the airways that does not participate in gas exchange
Accounts for about 1/3 of VT
***MV= VT x RR*
151
what's tidal volume?
Volume= flow x time
| The volume above FRC
152
what's peak pressure?
This is the pressure due to the sum of airway pressure and alveolar pressure
- A rising peak pressure --> the possibility of airway narrowing!!
- Endotracheal tube being kinked (or chewed on)
- Ventilator tubing full of fluid
- Heat and moisture exchanger being waterlogged
- Secretions building up on the inside of the endotracheal tube
- Bronchospasm-#1 clue
153
what is the #1 reason for bronchospasm?
high peak pressures
154
what is airway pressure?
Pressure due to the resistance of the airways
As soon as flow stops, the pressure due to airway resistance drops to zero
155
what is plateau pressure?
- Relationship between volume and compliance
- Unrelated to flow
- The pressure in the circuit when the breath is "held“ (i.e. the tidal volume is inside the patient without any flow going in or out
156
what is the relationship between volume and compliance?
plateau pressure
157
what is peep?
The alveolar pressure at the end of expiration (positive end expiratory pressure)
158
**what increases as you increase the PEEP?
alveolar volume also increases. at first this relationship is linear (0-10 peep) after 15 alveolar pressure increases but not volume
159
what's Peak inspiratory flow?
This is the flow generated during the inspiratory phase
160
what is Peak expiratory flow?
It is generated by the elastic recoil of the patients lungs and chest wall
A low expiratory flow obviously suggests you have an airway obstruction (COPD air trapping-> no recoil)
161
what's I:E Ratio?
Total-ventilator-controlled support
Assisted-controlled ventilatory support
Spontaneous ventilatory support
Ratio of inspiratory time to expiratory time
Normal I:E ratio at rest/asleep 1:2
**How many breaths can one breathe in 1 minute?
In pathologic states causing airflow obstruction expiratory time is typically prolonged
Ex: COPD
162
classifications of mechanical ventilations?
Total-ventilator-controlled support
Assisted-controlled ventilatory support
Spontaneous ventilatory support
163
what sets each mode apart?
Based on variations of the following variables:
* *Trigger: what initiates the breath (controlled vs. assisted)
* *Limit: end-point of what is to be achieved; the “target” ( vs. pressure)
* *Cycle: what results in the end of a breath cycle (expiration)
164
Continuous Mandatory Ventilation (CMV)
Trigger- 100% Machine
Limit variable- Volume/flow OR pressure
Cycle- Time
If a set VT and RR are determined--> predictable!
Patient respiratory efforts are ignored.
Choice between volume and pressure not supported by definitive evidence
Volume modes **typically chosen if maintaining a specific MV** is needed (think back on the formula)
Pressure mode may be more appropriate **in pathologic conditions affecting resistance/elasticity**
165
Volume Control (VCV)
Trigger- 100% ventilator elapsed time
Limit variable- flow
Cycle- volume
A set tidal volume (VT) is delivered with each inspiration
The amount of pressure will **fluctuate based on the resistance and compliance of the patient’s lungs and ventilator circuit
Modern ventilators have secondary limits on PIP to guard against barotrauma – will not deliver volume and machine cycles into expiratory cycle
166
what are the indications for Volume Control (VCV)
Indications:
Patients requiring total ventilatory support
Decreases WOBPt. with very high MV (ie. Metabolic acidosis).
167
selecting tidal volume
Normal resting VT is **5 to 7 mL/kg
Lung volumes correlate with height rather than weight,
VT selection should be based on IBW rather than actual weight to avoid lung over-distention
men kg=50+2.3(height in inches-60)
women kg=45.5+2.3(height in inches-60)
168
large Vt can result in ?
Large VT can result in:
Cardiovascular compromise
Barotrauma
Ventilator-induced or ventilator-associated (VALI) lung injury
Increased mortality seen in ICU patients
169
the elastic recoils generates what?
Peak expiratory flow
170
Extubation Criteria
Subjective:
Follows commands
Clear oropharynx/hypopharynx
Intact gag reflex
Minimal ET inhalational agents
Sustained head lift >5sec, sustained hand grasp
Indiicates approximately 30% receptor occupation
Objective(more reliable)
Tidal volumes >6ml/kg
Vital capacity 10 ml/kg or >
T1/T4 ratio >0.7
Ratio corresponds to TOF 4/4 with sustained tetanus and normal TV/VC
Means 25% of receptors can still be occupied
Sustained tetanus (5sec)
171
What risks are associated with anesthesia?
**Potential difficulty for adequate ventilation/intubation
Induction/emergence is “stressful” for the body
Maintenance of anesthesia is associated with variable degrees of stimulation, fluid shifts, & blood loss
**Anaphylactic reactions to medications may occur
**Injuries may be incurred airway trauma during laryngoscopy/neuropathy from improper patient positioning
172
contraindications for deep extubation
difficult intubation/mask ventilation, risk of aspiration (GERD,) airway edema, ↑ airway irritability
173
when to use the eschmann introducer (bougie)
Cormack and Lehan grade 2 and 3
