UNIT 1 - RESPIRATORY Flashcards
1
Q
What are the sensory functions of the Ophthalmic branch (V1) of the Trigeminal nerve (CN 5)?
A
Nares, & anterior 1/3 of nasal septum
2
Q
What is the motor function of the Mandibular branch (V3) of the Trigeminal nerve (CN 5)?
A
Mastication
3
Q
Which cranial nerve is responsible for the sensory innervation of the soft palate and oropharynx?
A
Glossopharyngeal (CN 9)
4
Q
What is the primary motor function of the Vagus nerve (CN 10)?
A
Innervates intrinsic muscles of the larynx
5
Q
What anatomical structures are included in the laryngeal cartilages?
A
- Epiglottis
- Thyroid
- Cuneiform (Pair)
- Corniculate (Pair)
- Arytenoids (Pair)
- Cricoid
6
Q
What is the purpose of anesthetizing the airway during awake intubation?
A
To minimize discomfort and facilitate intubation
7
Q
True or False: A unilateral recurrent laryngeal nerve injury causes respiratory distress.
A
False
8
Q
What are the intrinsic muscles of the larynx involved in phonation?
A
- Posterior Cricoarytenoid
- Lateral Cricoarytenoid
- Cricothyroid
- Thyroarytenoid
9
Q
Fill in the blank: The primary function of the upper airway is _______.
A
Warming, humidifying, filtering particles, and preventing aspiration
10
Q
What anatomical structures mark the beginning and end of the lower airway?
A
Begins at the trachea & ends at the alveoli
11
Q
What is the primary determinant of CO2 elimination?
A
Alveolar ventilation
12
Q
What is the formula for minute ventilation?
A
Minute ventilation = TV x RR
13
Q
What happens to intrapleural pressure during forced expiration?
A
It becomes positive
14
Q
Which type of pneumocyte provides the surface for gas exchange?
A
Type 1 Pneumocyte
15
Q
What is the relationship defined by the Law of Laplace in alveoli?
A
P = 2T/R
16
Q
What is the consequence of a right-to-left shunt in terms of hypoxia?
A
It leads to hypoxia due to poorly ventilated areas
17
Q
What does the A-a gradient help diagnose?
A
The cause of hypoxia
18
Q
What is the normal P50 value for the oxyhemoglobin dissociation curve?
A
26-27 mmHg
19
Q
Fill in the blank: The formula for oxygen content in blood is CaO2 = _______.
A
(1.34 • Hgb • SaO2) + (PaO2 • 0.003)
20
Q
What is the effect of increased 2-3 DPG on the oxygen dissociation curve?
A
It causes a right shift, facilitating oxygen unloading
21
Q
What factors can increase the A-a gradient?
A
- Aging
- Vasodilators
- Right to left shunt
- Diffusion limitations
22
Q
True or False: Supplemental O2 is effective in reversing hypoxemia caused by shunt.
A
False
23
Q
What condition is the most common cause of hypoxia in the PACU?
A
Atelectasis
24
Q
What type of lung volume cannot be directly measured through spirometry?
A
Residual Volume (RV)
25
What does the term 'compliance' refer to in respiratory physiology?
ΔV/ΔP
26
What is the primary function of surfactant in the alveoli?
To reduce surface tension and prevent alveolar collapse
27
What is the effect of the Haldane effect in terms of CO2 transport?
↑PaO2 displaces CO2 from hemoglobin
28
What is the significance of the transpulmonary pressure?
It determines lung expansion
29
What is the difference between anatomical and physiological dead space?
Anatomical dead space includes conducting airways, while physiological dead space includes both anatomical and alveolar dead space
30
What is produced during RBC glycolysis?
2-3 DPG
31
What happens to Hgb when PaO2 is above 100 mmHg?
Hgb is fully saturated; increasing FiO2 increases dissolved O2 but not O2 binding to Hgb
32
What is the Bohr effect?
↑PaCO2 & H+ cause Hgb to release O2
33
What is the Haldane effect?
↑PaO2 displaces CO2 from Hgb
34
What is the Hamburger shift?
Cl- exchanges for HCO3- in RBCs to maintain electroneutrality
35
What is the normal SaO2 and corresponding PaO2 for 90% saturation?
PaO2 60 mmHg
36
What is the affinity of CO for Hgb compared to O2?
CO has a 200-250 X greater affinity for Hgb than O2
37
What is the net gain of ATP from glycolysis?
2 ATP
38
What is the net gain of ATP from oxidative phosphorylation?
34 ATP
39
What happens to pyruvate acid in the absence of O2?
It is converted into lactic acid
40
How is CO2 carried in the blood? List the three ways.
* Bicarbonate Ion (HCO3-) - 70%
* Bound to Hgb as carbamino compound - 23%
* Dissolved in plasma - 7%
41
What is hypercapnia?
PaCO2 > 45 mmHg
42
What are the consequences of hypercapnia?
* Hypoxemia
* Acidosis
* Cardiac/smooth muscle depression
* SNS stimulation
* ↑P50
* ↑K+
* ↑Ca++
* ↑PVR
* ↑ ICP
* ↓ LOC
43
What happens to minute ventilation with PaCO2 between 20-80 mmHg?
Minute ventilation increases linearly
44
What is the apneic threshold?
The highest PaCO2 where a person will not breathe
45
Fill in the blank: CO2 is ______ more soluble than O2.
20 X
46
What is the total CO2 content of arterial blood?
48 ml CO2/100 ml blood
47
What is the primary respiratory center located in the medulla?
Dorsal Respiratory Group (DRG)
48
What is the role of the pneumotaxic center?
Inhibits DRG and shuts off inspiration
49
What reflex prevents over-stretching of the lungs?
Hering-Breuer Inflation Reflex
50
What do central chemoreceptors respond to?
↑ H+ in the CSF
51
Where are peripheral chemoreceptors located?
At the carotid bodies and transverse aortic arch
52
What is HPV?
A local reaction to reduction in alveolar O2 tension
53
What is the primary mechanism of bronchoconstriction?
PNS stimulation of M3 receptor
54
List two direct acting bronchodilators.
* Beta-2 agonists (e.g., Albuterol, Salmeterol)
* Anticholinergics (e.g., Atropine, Ipratropium)
55
What does PFT stand for?
Pulmonary Function Test
56
What does FEV1/FVC ratio help diagnose?
Restrictive vs obstructive lung disease
57
What is the most common finding in asthma?
Respiratory alkalosis with hypocarbia
58
What is a common treatment for bronchospasm?
Short acting inhaled beta-2 agonist (e.g., Albuterol)
59
What can trigger bronchospasm besides asthma?
* Mechanical obstruction of ETT
* Light anesthesia
* Pulmonary aspiration
60
What is the effect of sub-anesthetic doses of gas and IV drugs on the hypoxic ventilatory drive?
They depress the hypoxic ventilatory drive
61
What is bronchospasm?
A sudden constriction of the muscles in the walls of the bronchioles.
62
What is an acute asthma attack?
A sudden worsening of asthma symptoms due to increased airway inflammation and constriction.
63
What is endobronchial intubation?
Insertion of a tube into the bronchus to secure an airway.
64
What is pneumothorax?
A collection of air in the pleural space that can cause lung collapse.
65
What is pulmonary aspiration?
Inhalation of food, liquid, or other substances into the lungs.
66
What is pulmonary edema?
Fluid accumulation in the lung tissue, affecting gas exchange.
67
What does PE stand for?
Pulmonary Embolism.
68
List common presentations of bronchospasm.
* Wheezing
* Decreased breath sounds
* Increased airway resistance
* Increased peak inspiratory pressure (PIP) with normal plateau pressure
* Increased alpha angle on capnography
69
What is the initial treatment for bronchospasm?
* 100% FiO2
* Deepen anesthetic (Volatiles, propofol, lidocaine, ketamine)
* Short acting inhaled beta-2 agonist (Albuterol)
* Inhaled ipratropium
* Epinephrine 1 mcg/kg IV
* Hydrocortisone 2-4 mg/kg IV
* Aminophylline
* Helium-oxygen (Heliox)
70
What characterizes COPD?
A reduction in maximal expiratory flow and slower forced emptying of the lungs.
71
What are the two main components of COPD?
* Chronic bronchitis
* Emphysema
72
What are the key characteristics of chronic bronchitis?
* Hypertrophied bronchial mucus glands
* Chronic inflammation
73
What are the key characteristics of emphysema?
* Enlargement and destruction of the airways distal to the terminal bronchioles.
74
What are common etiologies of COPD?
* Smoking
* Respiratory infection
* Environmental pollutants
* Alpha-1 antitrypsin deficiency
75
Describe the presentation of chronic bronchitis.
* Copious sputum
* Increased hematocrit
* 'Blue Bloater'
* Increased pulmonary vascular resistance (PVR) leading to right heart failure
76
Describe the presentation of emphysema.
* Cough with exertion
* Scant sputum
* 'Pink Puffer'
* Normal/slightly reduced PaCO2
* Increased PVR leading to right heart failure
77
What is alpha-1 antitrypsin deficiency?
A genetic disorder that can lead to panlobular emphysema due to unchecked alveolar elastase.
78
What occurs with inability to exhale in COPD?
Gas trapping leading to increased residual volume (RV).
79
What is the effect of chronic elevated PaCO2 in COPD?
It causes respiratory acidosis, and kidneys reabsorb bicarbonate, leading to compensatory metabolic alkalosis.
80
What is the recommended SaO2 target for patients with severe COPD?
Maintain SaO2 between 88-92% to minimize the risk of O2-induced hypercapnia.
81
What spirometry findings are indicative of COPD?
* Increased RV, FRC, TLC
* Decreased FEV1, FEV1/FVC ratio, FEF 25-75%
82
What FEV1/FVC ratio after bronchodilator therapy indicates COPD?
An FEV1/FVC of <70%.
83
What are key considerations for anesthesia in COPD patients?
* Consider regional anesthesia for extremities & lower abdomen
* Avoid neuraxial anesthesia if sensory blockade >T6
* Be cautious with excessive sedation and ventilatory depression
84
What are ventilation considerations for patients with COPD?
* Large tidal volumes (10-15 ml/kg)
* Use 6-8 ml/kg IBW
* Short inspiratory rate and longer expiratory time
* Slow respiratory rate, add PEEP but observe for dynamic hyperinflation
85
What is dynamic hyperinflation?
Breath stacking due to high minute ventilation and reduced expiratory flow.
86
What are the consequences of dynamic hyperinflation?
* Hypotension
* Barotrauma
* Pneumothorax
87
What are common causes of restrictive lung disease?
* Acute intrinsic (Pulmonary edema)
* Chronic intrinsic (Interstitial lung disease)
* Chest wall diseases
* Other (Obesity, ascites, pregnancy)
88
What are the characteristics of restrictive lung disease?
* Decreased lung volumes and capacities
* Decreased compliance
* Intact pulmonary flow rates
89
What is the diagnostic criterion for restrictive lung disease based on FEV1 and FVC?
An FEV1 and FVC <70%.
90
What are ventilation considerations for restrictive lung disease?
* Smaller tidal volume (6 mL/kg IBW)
* Faster respiratory rate (14-18 bpm)
* Keep peak inspiratory pressure < 30 cm H2O
* Prolong inspiration time (I:E ratio 1:1)
91
What is aspiration pneumonitis?
Inflammation of the lungs due to inhalation of foreign materials.
92
What are the common risk factors for aspiration pneumonitis?
* Pregnancy
* Trauma
* Emergency surgery
* GI obstruction
93
What are the signs and symptoms of aspiration pneumonitis?
* Hypoxemia
* Dyspnea
* Tachypnea
* Cyanosis
* Tachycardia
* Hypertension
94
What is the primary treatment for aspiration pneumonitis?
* Tilting head downward
* Suctioning
* Securing airway
* Applying PEEP
95
What are the criteria for safe discharge after aspiration?
* No new cough or wheeze
* No radiographic evidence of pulmonary injury
* SpO2 decrease ≤10% from preoperative values on room air
* A-a gradient ≤ 300 mmHg
96
What is Mendelson’s syndrome?
Chemical aspiration pneumonitis due to aspiration of gastric contents.
97
What is the most common cause of ventilator-associated pneumonia (VAP)?
Introduction of bacteria to the airway via endotracheal tube (ETT).
98
List the prevention strategies for VAP.
* Hand washing
* Keeping head of bed > 30 degrees
* Daily spontaneous breathing trials
* Limiting sedation
* Oropharyngeal decontamination
* Subglottic suctioning
99
What are the common culprits of VAP?
* Pseudomonas aeruginosa
* Staphylococcus aureus
100
What is the treatment for VAP?
Start broad-spectrum antibiotics and then switch to targeted antibiotics once the organism is identified.
101
What are the types of pneumothorax?
* Closed
* Open
* Tension
102
What are the signs and symptoms of tension pneumothorax?
* Hypoxemia
* Increased PIP
* Asymmetric chest wall movement
* Absence of unilateral breath sounds
* Tracheal shift to opposite side
* Tachycardia
* Hypotension
103
What is the emergency treatment for tension pneumothorax?
Insert a 14G angiocath into the second intercostal space mid-clavicular line or the 4th/5th intercostal space at the anterior axillary line.
104
What is flail chest?
A consequence of blunt chest trauma characterized by paradoxical movement of the chest wall.
105
What are the consequences of flail chest?
* Alveolar collapse
* Hypoventilation
* Hypercarbia
* Hypoxia
106
What is venous air embolism (VAE)?
Gas embolism that travels to the right heart and lodges in the pulmonary outflow tract or pulmonary artery.
107
What are the signs and symptoms of VAE?
* Air observed in TEE
* Mill Wheel murmur on precordial Doppler
* Decreased EtCO2
* Increased EtN2
* Increased pulmonary artery pressure (PAP)
* Hypotension
108
What is the treatment for VAE?
* Administer 100% FiO2
* Flood surgical field with normal saline
* Discontinue gas insufflation
* Place patient in left lateral decubitus position
* Aspirate from central line
109
What defines pulmonary hypertension?
Mean pulmonary artery pressure (PAP) >25 mmHg.
110
What increases pulmonary vascular resistance (PVR)?
* Hypoxia
* Hypercarbia
* Acidosis
* Sympathetic nervous system stimulation
* Pain
* Hypothermia
* Increased intrathoracic pressure
111
What decreases pulmonary vascular resistance (PVR)?
* Increased PaO2
* Hypocarbia
* Alkalosis
112
What are the anesthetic considerations for pulmonary hypertension?
* Do not hold preoperative medications that reduce PVR
* Treat hypotension aggressively
* Epidural anesthesia is better tolerated than spinal anesthesia
113
What is carboxyhemoglobin?
A compound formed when carbon monoxide binds to hemoglobin, causing a left shift in the O2 dissociation curve.
114
What is the treatment goal for carbon monoxide poisoning?
Reduce carboxyhemoglobin levels to < 5%.
115
What are the indications for hyperbaric oxygen therapy?
* CO poisoning
* Gas embolism
* Anaerobic infections (Gas gangrene)
* Decompression sickness
116
What drugs can be administered via endotracheal tube (ETT)?
NAVEL: Narcan, Atropine, Vasopressin, Epinephrine, Lidocaine.
117
What are the benefits of endotracheal intubation?
* Patent airway
* Controlled ventilation
* Ventilation with high airway pressure
* Secured airway
* Removal of secretions
118
What are the anatomical characteristics of a difficult intubation?
* Short, muscular neck
* Receding mandible
* Protruding maxillary incisors
* Inability to visualize uvula
* Limited temporomandibular joint mobility
* Limited cervical mobility
119
What are the contraindications to fiberoptic bronchoscopy?
* Hypoxia
* Heavy airway secretions
* Bleeding not relieved with suction
* Local anesthetic allergy
* Inability to cooperate
120
What are the best predictors of postoperative pulmonary complications?
* FEV1 < 40%
* DLCO < 40%
* VO2 Max < 15 mL/kg/min
121
What is the most common problem with one-lung ventilation (OLV)?
Intrapulmonary shunt.
122
What should be done to manage hypoxemia during OLV?
* Verify delivery of 100% FiO2
* Check double-lumen tube (DLT) position
* Apply CPAP to non-dependent lung
* Apply PEEP to dependent lung
* Reinflate collapse lung if necessary
123
What are the potential complications of DLT positioning?
* DLT in too far leading to upper lobe not being ventilated
* DLT not deep enough leading to failure to achieve lung separation
* DLT in the wrong bronchus causing wrong lung collapse
124
What are the sizes for double-lumen tubes in adults?
* Female: 35-37 Fr
* Male: 39-41 Fr
125
What is a bronchial blocker?
A device used for lung isolation during one-lung ventilation.
126
What are the benefits of using a bronchial blocker?
* No need to exchange ETT after surgery
* Can be passed through single lumen ETT for OLV
127
What are the downsides of using a bronchial blocker?
* Operative lung slow to collapse
* Balloon can slip into trachea leading to contamination
128
What is a Bronchial Blocker?
A device advanced into the main bronchus to assist in one-lung ventilation (OLV) without needing to exchange the endotracheal tube (ETT) after surgery.
## Footnote
Benefits include the ability to insufflate oxygen into the non-ventilating lung and suction air from it, but cannot suction blood or secretions.
129
What is the absolute contraindication for mediastinoscopy?
Previous mediastinoscopy due to scarring.
## Footnote
The most common reason for performing this procedure is bronchogenic carcinoma.
130
What complications can arise from mediastinoscopy?
* Hemorrhage
* Pneumothorax
* Tearing of great vessels
* Chylothorax
* Bronchospasm from airway manipulation
* Air embolism
* Arrhythmias
* Esophageal laceration
## Footnote
Large bore IV and PRBCs should be ready due to the risk of hemorrhage.
131
What are the indications for tracheal resection?
* Tracheal stenosis
* Tracheomalacia
* Tumor
* Vascular lesions
* Congenital malformations
## Footnote
Postoperatively, the patient's neck should be flexed for several days to reduce tension on the anastomosis.
132
What is ARDS?
A form of non-cardiogenic pulmonary edema caused by inflammation injury leading to diffuse alveolar destruction.
## Footnote
Hypoxia is the #1 manifestation of ARDS.
133
What are the key pathological features of ARDS?
* Protein rich pulmonary edema
* Loss of surfactant
* Hyaline membrane formation
* Possible long-term lung injury
## Footnote
CXR reveals bilateral opacities and diffuse patchy alveolar infiltrates.
134
What are the five types of hypoxia?
* Hypoxic hypoxia
* Anemic hypoxia
* Stagnant hypoxia
* Histotoxic hypoxia
* Hypoxia due to pulmonary disease
## Footnote
Hypoxic hypoxia is also referred to as diffusional hypoxia.
135
What does the Mallampati score assess?
The oropharyngeal space to predict intubation difficulty.
## Footnote
A score of 3 or 4 indicates a more difficult intubation.
136
What is the normal range for the inter-incisor gap?
2-3 finger breadths (4 cm).
## Footnote
A smaller gap increases intubation difficulty.
137
What does a Thyromental Distance (TMD) of less than 6 cm indicate?
Increased risk of difficult intubation.
## Footnote
A TMD greater than 9 cm also indicates increased risk.
138
What is assessed in the Mandibular Protrusion Test (MPT)?
The function of the temporomandibular joint.
## Footnote
Class 3 correlates with an increased risk of difficult intubation.
139
What is the significance of the Cormack & Lehane Score?
Grades 1 & 2A indicate easier intubation while grades 2B, 3, and 4 indicate harder intubation.
## Footnote
Grade 4 requires an alternative approach to intubation.
140
What are the risk factors associated with Difficult Mask Management?
* Beard
* Obesity (BMI > 26 kg/m2)
* No teeth
* Elderly (> 55 years)
* Snoring
## Footnote
These factors increase the difficulty of mask ventilation.
141
What is the narrowest region in adults and pediatric airways?
Adult: glottic opening; Pediatric: cricoid ring (fixed) and vocal cords (dynamic).
## Footnote
Pediatric larynx is funnel-shaped (<5 years).
142
What is the first-line treatment for laryngospasm?
* FiO2 100%
* Remove noxious stimuli
* Deepen anesthesia
* Larson’s maneuver
* Chin lift
* CPAP 15-20 cmH2O
## Footnote
Consider succinylcholine for severe cases.
143
What are the NPO guidelines for fasting before surgery?
* 2 hours = Clear liquids
* 4 hours = Breast milk
* 6 hours = Nonhuman milk, infant formula, solid food
* 8 hours = Fried or fatty foods
## Footnote
These guidelines help minimize aspiration risk.
144
What is the cricoid pressure applied during Rapid Sequence Intubation (RSI)?
20 Newtons (~2 kg) before loss of consciousness, 40 Newtons (~4 kg) after.
## Footnote
Cricoid pressure can cause airway obstruction and impair direct laryngoscopy.
145
What are the three key causes of angioedema?
* Anaphylaxis
* ACE inhibitors
* C1 esterase deficiency (hereditary)
## Footnote
Treatment varies by cause, including epinephrine for anaphylaxis.
146
What is Ludwig’s Angina?
A bacterial infection that leads to cellulitis in the floor of the mouth, risking airway obstruction.
## Footnote
Best airway management is awake intubation or awake tracheostomy.
147
What congenital conditions are associated with cervical spine abnormalities?
* Klippel Feil
* Trisomy 21 (Down syndrome)
* Goldenhar
## Footnote
These conditions can affect airway management.
148
What is the sniffing position and its relevance?
Cervical flexion and atlanto-occipital extension to align the oral, pharyngeal, and laryngeal axes.
## Footnote
Particularly important for intubation.
149
What is the maximum cuff pressure for an LMA?
60 cm H2O (target 40-60 cm H2O).
## Footnote
Excessive cuff pressure can lead to nerve injuries.
150
What is the purpose of the Combitube?
A double lumen device used for blind placement in the hypopharynx, providing secure airway and aspiration protection.
## Footnote
Size is determined by the patient's height.
151
What is the King Laryngeal Tube?
A single lumen device similar to the Combitube, with child sizes available.
## Footnote
It has a single inflation port and is disposable.
152
What is the purpose of the technique to decompress the stomach?
Useful for the obese population
## Footnote
Minimal training required.
153
What are contraindications for stomach decompression?
* Intact gag reflex
* Prolonged use >2-3 hours
* Esophageal disease (Zenker’s diverticulum)
* Ingestion of caustic substances
154
What distinguishes the King Laryngeal Tube from the Combitube?
Single lumen for ventilation & single inflation port
## Footnote
Child sizes are available.
155
What is the King LTS-D?
A disposable device that includes a second lumen to pass a gastric tube for suctioning the stomach.
156
What is the primary use of a Flexible Fiberoptic Bronchoscope?
Used for indirect laryngoscopy in awake or asleep patients.
157
What are relative contraindications for using a Flexible Fiberoptic Bronchoscope?
* Hypoxia
* Bleeding
* Lack of patient cooperation
158
What should be used before the insertion of a Flexible Fiberoptic Bronchoscope?
* Defogger
* Antisialagogue
* Vasoconstrictor (Nasal approach)
159
How do you control the movements of the Flexible Fiberoptic Bronchoscope?
* Non-dominant hand moves the lever (Controls)
* Dominant hand holds the cord
160
What are the best drug choices for awake Fiberoptic Bronchoscope intubation?
* Precedex
* Remi
* Ketamine
* Versed
161
What is the Bullard Laryngoscope used for?
It is a rigid, fiberoptic device used for indirect laryngoscopy.
162
What are the indications for using the Bullard Laryngoscope?
* Small mouth opening (Minimum mouth opening = 7mm)
* Impaired cervical spine mobility
* Short, thick neck
* Treacher Collins syndrome
* Pierre Robin syndrome
163
What is an Intubating Stylet also known as?
Eschmann introducer (IE) or Gum Elastic Bougie.
164
How can proper placement of an Intubating Stylet be confirmed?
By feeling clicks of the tracheal rings.
165
What is the worst time to use an Intubating Stylet?
With a CL class 4 view.
166
What is the purpose of a Lighted Stylet?
A blind intubation technique that transilluminates the anterior neck to facilitate endotracheal intubation.
167
What are the benefits of using a Lighted Stylet?
* Useful for anterior airway
* Useful with small mouth opening
* Requires very little neck manipulation
* Less stimulating than DL
* Less sore throat than DL
168
What are the disadvantages of using a Lighted Stylet?
* Difficult to use in patients with a short, thick neck
* Should not be used in emergencies or can't ventilate can't intubate situations
* Not to be used in the presence of a tumor, foreign body, airway injury, or epiglottitis
169
What is Retrograde Intubation?
A blind procedure where tracheal intubation is accomplished by passing the ETT over a wire inserted via the cricothyroid membrane puncture.
170
What are the indications for Retrograde Intubation?
* Unstable C-spine
* Upper airway bleeding
* Best used when intubation has failed but ventilation is still possible
171
What are contraindications for Retrograde Intubation?
* Unable to identify neck landmarks (Severe obesity)
* Pretracheal mass (Thyroid goiter)
* Neck flexion deformity
* Tracheal stenosis or tumor obstructing the wire path
* Coagulopathy
* Infection
172
What are potential complications of Retrograde Intubation?
* Bleeding
* Pneumomediastinum
* Pneumothorax
* Trigeminal nerve trauma
* Breath-holding
* Wire travels in the wrong direction
173
What is a Percutaneous Cricothyroidotomy used for?
Used in emergent situations with transtracheal jet ventilation.
174
What are contraindications for Percutaneous Cricothyroidotomy?
* Upper airway obstructions
* Laryngeal injury
175
What is the difference between Cricothyroidotomy and Tracheostomy?
Cricothyroidotomy is created via a small incision through the cricothyroid membrane; Tracheostomy takes time and is less attractive for emergencies.
176
What does the ASA Difficult Airway Algorithm emphasize?
Optimizing oxygenation, limiting attempts, and being aware of time and O2 saturation.
177
What is the primary goal in a 'Can’t ventilate & can’t intubate' scenario?
Calling for help, placing a supraglottic airway device, and possibly waking the patient.
178
What strategies are suggested for extubation?
* Enlisting skilled help
* Optimizing oxygenation
* Using an airway exchange catheter (in adults)
* Consideration of elective tracheostomy
179
What is the importance of the airway reflexes during extubation?
Should be intact to protect the airway and reduce the risk of aspiration.
180
What is an Airway Exchange Catheter (AEC)?
A long, thin, flexible tube that maintains direct access to the airway after extubation.
181
What are the complications associated with using an AEC?
* Barotrauma/pneumothorax
* Inability to replace ETT
