Orals: Lungs/airway Flashcards
1
Q
Who needs PFTs?
A
Any patient who is having a lung resection
2
Q
How do you know you are positioned correctly with DLT?
A
Look for tracheal rings!
Bilateral chest rise and sounds
3
Q
How do you place a DLT?
A
Turn on 100% FiO2
Lube tube and antifog
DL with a MAC, advance thru cords until black mark gone then twist clockwise to advance past cords, then turn 90 degrees to the left for a left sided tube. Then listen!
Check with bronchoscope for tracheal rings and carina
4
Q
How do you initiate one lung ventilation?
A
- Confirm tube position through bronchoscope
- Turn on 100% FiO2
- Lower tidal volumes and go 1:1 I:E ratio, increase PEEP
- Due recruitment maneuver
- Clamp desired lung off and open top, keep bronchial cuff up to avoid leaking air into independent lung
5
Q
How do you troubleshoot hypoxemia in one lung ventilation?
A
- Check tube placement by auscultation and bronchoscopy - adjust, check ECG and ABG to ensure adequate perfusion and no other causes
- 100% FiO2
- Suction tubes
- Recruitment maneuver
- Apneic oxygenation of independent lung
- PEEP to independent lung
- Switch to TIVA since volatiles inhibit HPV
- Clamp pulmonary artery to decease the shunt if refractory
- Go back to 2 lung ventilation
Consider PTX of dependent lung!
6
Q
What are options for tube placement?
A
Bougie, Single lumen tube, then exchange
LMA, DL, then place DLT
Fiber optic
7
Q
How do you resume double lung ventilation?
A
100% FiO2
Suction tubes
Recruitment breaths
Take down bronchial cuff
8
Q
What is the mechanism of bradycardia with laryngoscopy?
A
Likely due to vagal response and possibly opioids on induction
9
Q
Describe the steps for adult awake intubation
A
- glycopyrrolate 0.2-0.4mg IM or IV and then wait 15 minutes
- Oxymatazoline to each nostril
- Topicalization: nasal swab with lido, lido on oral airway and suck, inhaled lido, LTX tonsillar pillars,
- wrap and grab tongue, pull forward, OvaSapian if needed
- oxygen to suction port, lube, go
- cric kit or surgeon nearby. Also, other tools - LMA, BOUGIE, CATHETER
Use precedex or ketamine
10
Q
What kind of ETT is most resistant to fire with a CO2 laser?
A
Metal wrapped
11
Q
What kind of ETT is most resistant to fire for Nd:yag laser?
A
Silicon/rubber
12
Q
What is the only GI ppx shone to decrease risk of VAP?
A
Sucralfate
13
Q
What are the dangers of tracheostomy?
A
Subcutaneous emphysema
False tract
Bleeding
Nerve injury
14
Q
What could contribute to difficult vent wean?
A
Hypocalcemia
Hypophosphatemia
15
Q
What is TRALI? How do you diagnose and treat it?
A
Diagnosis of exclusion
Noncardiogenic pulmonary edema caused by anti-HLA donor antibodies to plasma proteins (caused by FFP or platelet)
Happens within 6 hours of transfusion
ARDSnet, CXR, O2
16
Q
What is the pathophysiology of OSA?
A
Intermittent episodes of apnea caused by pharyngeal muscle collapse (often due to increased fat deposition) during sleep. Results in lower PaO2 and higher PaCO2 thus increasing ventilators drive and the RAS. So interrupts REM sleep resulting in daytime sleepiness.
Higher risk of pulmonary hypertension, arrythmia, CHF
17
Q
What are the 3 components of the periop risk assessment for OSA?
A
- OSA severity (based on symptoms, AHI)
- Invasiveness of surgery
- Need for opioids
18
Q
What AHI classifies as moderate OSA?
A
21-40
19
Q
What periop risk score is increased periop risk for OSA?
A
4
20
Q
What score means significant higher periop risk for OSA?
A
5-6
21
Q
How long should OSA patients be kept after their last hypoxia episode on room air?
A
7 hours
22
Q
What AHI score correlates with severe in peds?
A
Greater than 10
23
Q
What AHI correlates with moderate in Peds?
A
6-10
24
Q
What are you worried about in a case for laser treatment of polyps?
A
Airway fire
Infectious particles in the air
Laser damage to eyes
Polyps falling into the throat
Anesthetic management: jet ventilation with low FiO2
Goggles and tight fitting masks for everyone
25
What would you do if you had a double lumen tube in the right place but the independent lung kept inflating?
Put more air in the balloon
| Change ventilation modes and make sure it didn't go past the original peak inspiratory pressure that causes inflation
26
How would you induce a severe asthmatic?
Do albuterol nebulizer beforehand
Consider IV steroids ahead of time for delayed help
I would use ketamine for its bronchodilating properties
Fentanyl and lidocaine to blunt the airway response to intubation
27
How would you intubate a patient with an uncleared c-spine?
Remove anterior portion of the collar to get better mouth opening
Use MILS
Awake FO with Topicalization and ketamine to maintain airway reflexes
Or Mac blade/video laryngoscopy with Bougie and RSI
I would not use cricoid pressure because it can worsen your view and not proven to close esophagus
28
How would you remove a knotted PAC?
Simple manipulation and traction
Under fluoroscopy - pull knot to include the introducer and then withdraw both
Dotter basket
Use a tip-deflecting guide wire to untie the knot
Pull catheter tip down to the femoral vein and access by cut-down
Cardiotomy
29
What do you do for airway fire?
```
Stop ventilation/oxygen
Remove ETT
Douse airway with saline
Submerge tube in water
Mask the patient
Reintubate patient and assess airway with bronchoscope
Follow airway damage with serial ABGs and CXR
Consider bronchial lava ge and steroids
```
30
How do you manage negative pressure pulmonary edema?
CPAP
O2 supplementation
Diuretics
CXR/ABG to rule out other pathology
31
How would you do one lung ventilation in a patient with a tracheostomy?
Guide a univent tube thru the stoma, with blocker down the side you want blocked
Do a double lumen ETT from above
32
How will you ensure adequate preoxygenation?
3 minutes of tidal volume breathing
| 8 full breaths (vital capacity)
33
At PaO2 of 90, where are you on the sigmoid curve?
The flat part, so increases in saturation don't increase that much with increased PaO2
34
What is the correlating saturation with a PaO2 of 60? Where are you on the curve?
Correlates with a saturation of 90
35
How do you know you have found optimal PEEP?
When increasing PEEP doesn't increase your tidal volume meaning you are at the end of your pulmonary compliance. This is when your driving pressure is the lowest because all airways are open
Goal is to minimize PEEP so that airways are open at all times providing the most laminar flow and least resistance, but enough to prevent opening/closing of smaller airways that causes barotrauma
36
What is the diagnostic criteria for ARDS?
P/F ratio of less than 300
Acute onset (within 7 days of event)
Bilateral infiltrates on CXR
Respiratory failure not fully explained by cardiac or fluid overload
37
How do you treat ARDS?
1. Treat underlying cause - DIC, sepsis, hypotension
2. Mechanical ventilation with TV 6-8 ml/kg
3. Lowest FiO2 achievable and permissive hypercapnea
4 keep PIP < 30
38
What is in the STOPBANG criteria?
```
BMI > 35
Age over 50
HTN
Loud snoring
Witnessed apnea
Daytime sleepiness
Neck circumference over 40
Male
```
Less than 3 = low risk of OSA
5-8 = moderate to severe OSA
39
What is your differential for high peak airway pressures?
```
Kinked Tube/tubing
Endobronchial intubation
Mucus plug
PTX, hemothorax
Pleural effusion - CHF
```
Less likely :
Aspiration
40
What is the sign of intraparenchymal hemorrhage?
Blood coming up the tube
41
What will you do if you suspect intraparenchymal hemorrhage?
100% FiO2
Bronchial blocker
Guide single lumen to healthy lung with a scope
DLT (although not if already intubated)
Thoracic consult
Make sure you have adequate access for resuscitation
42
Would you order flow volume loops?
I would not because the evidence suggests they are poor predictors of perioperative respiratory complications and provide little info that a CT cannot and do not alter the anesthetic plan.
I would instead review the CT, perform detailed history and physical in both sitting and supine position
43
What are flow volume loops?
Plotted inspiratory and expiratory airflow during maximal inspiratory and expiratory efforts
44
Would you use an anticholinergic drug for aspiration prophylaxis?
I would not as these drugs decrease gastric motility and LES tone and are no longer recommended by ASA
45
How does an anticholinergic drug help with airway reactivity?
Reduces airway inflammation secondary to reduced vagal tone
| Reduced secretions
46
What is negative pressure pulmonary edema?
Noncardiogenic due to high intrapleural pressures due to vigorous inspiratory effort against an obstructed upper airway.
Get an increased transcapillary pressure gradient across alveoli which don't expand due to upper airway obstruction --> edema
47
What is the Cobb angle?
Perpendicular lines drawn from the top of the most cephalalad facing vertebra and the end plate of the most caudal facing vertebra.
Measure of the severity of scoliosis
48
What Cobb angle is associated with respiratory compromise?
Greater than 60
49
What is an abnormal Cobb angle?
10
50
What heart condition is associated with scoliosis?
Mitral valve prolapse or regurgitation
51
What is APRV?
Mode of ventilation that cycles between two levels of CPAP which allows gas movement in and out of the lungs while maintains continuous positive pressure
```
Have upper level pressure (inspiratory) = baseline airway pressure
Lower level (expiratory)
```
52
What are the characteristics of pressure support?
Only triggered by the patient, provides ventilatory support
Pressure cuts off when back pressures cause flow to drop below a certain point
The more patient effort the larger the tidal volume
53
What are the characteristics of pressure control?
Set inspiratory pressure with fixed inspiratory time
| Tidal volumes depend on lung compliance
54
What is CPAP.
Noninvasive ventilation that provides continuous pressure only with patient effort to recruit airways and decrease the work of breathing
55
What is set in volume control.
Tidal volume
| Respiratory rate
56
What is SIMV.
It delivers a set rate and volume, but synchronizes with patient effort
Patient efforts above the set RR are unassisted
57
What are some ways to decrease risk of airway fire?
Use laser resistant tube, rubber tube, reflective foil wrapping
Fill ETT cuff with saline
Low FiO2
Limit intensity/duration of laser treatment
Use jet ventilation/Apneic anesthetic technique
Have saline nearby
58
Would you extubate after an airway fire?
I would not regardless of extent of injury because inhalational injury can progress to life threatening airway edema
59
What is the treatment after airway fire?
Steroids to reduce airway edema
Humidified oxygen
Monitor for 24 hour with pulse oximetry and serial CXR
Extubate when you have a leak along with normal lung compliance and minimal vent support, no evidence of airway edema on bronchoscopy
60
How do you provide jet ventilation thru an exchange catheter?
Insert catheter less than 26 cm (don't use if ETT internal diameter is less than 4 cm
Use 100% FiO2 and pressure of 15-25 psi with less than 1 second of inspiratory time
61
How would you treat status asthmaticus?
```
Supplemental oxygen and intubation
B2 agonist
Corticosteroids
Antibiotics
IVF
Magnesium and calcium
Consider aminophylline (induce bronchodilation, stimulate central respiratory cycle, relax smooth muscle)
```
62
When would you intubate a patient with status asthmaticus?
When PaCO2 climbed above 50
63
What ventilatory goals do you have?
Decrease work of breathing
Maintain adequate oxygenation
Augment alveolar ventilation without causing lung injury
64
What can you give preop to optimize asthma?
Diphenhydramine to inhibit histamine induced bronchospasms
B2 nebulizer
100 mg of hydrocortisone (may have HPA suppression if on chronic steroids)
65
Why would you not give atropine preop to an asthmatic?
Because while it could decrease secretions and airway reactivity, it could caused increased viscosity of mucus and thus plugging
66
What is the pathophysiology of aspiration pneumonia?
Damage to the surfactant producing cells and pulm capillary endothelium with development of atelectasis, alveolar hemorrhage, edema and pulm HTN
X-rays don't show until 6-12 hours
67
When is antibiotic prophylaxis after aspiration indicated?
If aspirated feculent material (bowel obstruction)
Proven bacterial infection on cultures
Clinical course worsens after 2-3 days
68
What is lung cancer associated with?
```
Obstructive pneumonia
SVC syndrome
Pancoast syndrome
Mass effect and invasion of where and what
Paraneoplastic syndromes
```
69
What is pancoast syndrome?
Destructive lesion of the thoracic inlet involving brachial plexus:
Severe pain in the shoulder and ulnar distribution
Atrophy of hand and arm muscles
Horner's
Compression of blood vessels with edema
70
How would you evaluate someone with lung cancer for pneumonectomy preoperatively?
Order or review PFTs
CXR and Chest CT to look at tumor, mass effect, invasion
EKG
ABG
Echo
Consider VO2 max, stair climbing or 6 minute walk test
71
What do you do if ppoFEV1 is less than 40%?
Order V/q scan to assess contribution of oxygenation from lung to be resected
Order echo to evaluation RVF
72
What are the signs and symptoms of SVC syndrome?
```
Headache
Facial flushing/edema of HEENT, upper extremity
Venous distention in neck and face, upper chest
Chest pain
Dysphagia
Lightheaded mess
Orthopnea
Papilledema
Hoarseness
Nasal stuffiness
Nausea
Pleural effusion
Cyanosis (facial)
```
73
What are some common paraneoplastic syndromes?
SIADH
Lambert Eaton
Cushing's - hypokalemia, HTN, psychosis, alkalosis
Humoral hypercalcemia - arrythmias, weakness, N/v, renal failure
74
What are the best tests for pre-thoracotomy assessment?
ppoFEV1
DLCO
VO2 max
75
What VO2 max is concerning for increased risk of pulm complications?
Less than 15 ml/kg/min
76
How many stair climbs is indicative of high risk?
Less than 2
77
How many feet in 6 minutes indicates high risk?
Less than 2000 with VO2 max of less than 15
78
What ppoDLCO is considered increased risk?
<40%
79
What ppoFEV1 and DLCO is unacceptable for a pneumonectomy ?
Less than 20%
80
What PaO2 and PaCO2 indicates higher risk?
Less than 60
| Greater than 45
81
When should you get a V/Q scan to evaluate contribution of lung to be resected?
When FEV1 or DLCO are less than 80%
| When ppoFEV1 is less than 40%
82
What is the equation for estimating PaO2 on room air?
102 - (age/3)
83
How much does bicarbonate ride with every increase of 10 mmHg of CO2?
4
84
If a patient for pneumonectomy has a ppoFEV1 less than 40%, how will you determine if he will tolerate a pneumonectomy?
I would get
VO2 max to assess cardiopulmonary reserve
DLCO, PaO2 and PaCO2 to assess lung parenchymal function
VQ scan to assess contribution of resected lung
85
Why would you use a left-sided DLT over a right sided?
Because the right upper lobe bronchus proximity to the carina (1-2.5 cm) increase risk of obstruction
Left upper lobe is 5 cm from the carina
86
How would you use a left sided DLT in a left pneumonectomy?
I would retract the tube into the carina during suturing of the stump and be careful to avoid advancement of the tube
87
How does hypocapnea contribute to decreased PaO2?
By increasing resistance in the dependent lung (from increase in mean intra-alveolar pressure)
Inhibiting HPV in the nondependent lung (vasodilation)
These 2 effects result in shunting of blood to the independent, non-ventilated lung
88
What should you suspect if the patient has a precipitous drop in BP when switching from lateral to supine position after pneumonectomy?
Cardiac herniation into the empty side of the chest!
Put back in lateral decubitus! Order a CXR to look for mediastinal shift
89
At what ppoFEV1 could you consider extubation a pneumonectomy patient in the OR?
Greater than 40%
Between 30-40% as long as VO2 max, DLCO, PaO2 and PaCO2 meet the cut offs
Between 20-30% if all other criteria meet the cut offs, it was a VATS, and they have an epidural
90
What are the factors contributing to development of Afib after pneumonectomy?
```
Increased right heart afterload
Underlying cardiac disease
Pain stimulation of sympathetics
Intraoperative cardiac manipulation
Metabolic abnormalities
```
91
What is the equation for predicting PaO2 for a given FiO2?
FiO2 X 5
