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Flashcards in Respiratory Deck (63)
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1
Q

How is tobacco smoke harmful?

A

smoking increases SNS tone, sputum production, carboxyhemoglobin concentrations, and the risk fo infection.

2
Q

Short term effects of smoking cessation:

A
  • SNS stimulating effects of nicotine dissipate after 20-30 minutes
  • P50 returns to near normal in 12 hours (CaO2 improves)

(short term cessation does NOT reduce risk of post-op pulm complications.)

3
Q

Intermediate term effects of smoking cessation:

A

Return to normal pulmonary fx requires at least 6 weeks including:

  • airway fx
  • mucociliary clearance
  • sputum production
  • pulmonary immune function
  • hepatic enzyme induction subsides after 6 weeks.
4
Q

Pulmonary fx flow-volume loops:

A

Normal: upside down ice cream cone
Obstructive: normal inspiration with expiratory obstruction.
Restrictive: shape like normal, but loop is smaller and right shifted.
Fixed obstruction: inspiration and expiration are affected.
Extrathoracic obstruction: abnormal inhale, normal exhale.
Intrathoracic obstruction: normal inhale, abnormal exhale

5
Q

Treatment for acute bronchospasm?

A
100% FiO2
deepen anesthetic
inhaled beta-2 agonist (albuterol)
inhaled anticholinergic (ipratropium)
Epinephrine 1 mcg/kg IV
Hydrocortisone 2-4mg/kg IV (takes several hours)
Aminophylline
Helium-oxygen (Heliox) reduces airway resistance (decreases Reynold's number)
6
Q

What is alpha-1 antitrypsin deficiency (A1AD)?

A

Alveolar elastase is a naturally occurring enzyme that breaks down pulmonary connective tissue. It’s kept in check by alpha-1 antitrypsin (produced in the liver).

Deficiency of alpha-1 antitrypsin will eventually lead to pan lobular emphysema.

Liver transplant is the definitive tx for A1AD

7
Q

Goals and Strategies for mechanical ventilation in COPD patients:

A

GOAL: prevent barotrauma and reduce air trapping

  • low tidal volumes (6-8 mL/kg IBW)
  • increased expiratory time to minimize air trapping
  • slow inspiratory flow rate optimizes V/Q matching
  • Low levels of PEEP are ok, as long as there’s no air trapping
8
Q

Define restrictive lung disease:

A

Impaired lung expansion
Decreased lung volumes
Normal pulmonary flow rates

9
Q

Examples of intrinsic lung diseases:

A

(affect lung parenchyma)
ACUTE: aspiration, NPPE
CHRONIC: pulmonary fibrosis, sarcoidosis

10
Q

Examples of extrinsic lung diseases:

A

(affects areas around the lungs)
Chest wall/Mediastinum: Kyphoscoliosis, flail chest, neuromuscular disorders, mediastinal mass

Increased intraabdominal pressure: pregnancy, obesity, ascites

11
Q

Risk factors for aspiration pneumonitis:

A
trauma
emergency surgery
pregnancy
GI obstruction 
GERD
Peptic ulcer disease
Hiatal hernia
Ascites
Difficult airway management
cricoid pressure
impaired airway reflexes
Head injury
Seizures
Residual neuromuscular blockade
12
Q

Pharmacologic prophylaxis of aspiration pneumonitis:

A

ANTIACIDS: sodium citrate, sodium bicarbonate, magnesium triplicate
H2 ANTATGONISTS: ranitidine, cimetidine, famotidine
GI STIMULANTS: metoclopramide
PROTON PUMP INHIBITORS: omeprazole, lansoprazole, pantoprazole
ANTIEMETICS: droperidol, ondansetron

  • routine prophylaxis for those not at risk is not recommended.
  • *Anticholinergics to reduce the risk of aspiration is not recommended.
13
Q

What is Mendelson’s syndrome?

A

a chemical aspiration pneumonitis that was first described in OB patients receiving inhalation anesthesia.

Risk factors:
Gastric pH < 2.5
Gastric volume > 25mL (0.4mL/kg)

14
Q

Tx for aspiration:

A
  • Tilt head downward or to side.
  • Upper airway suction to remove particulate.
  • Lower airway suction is only useful for removing particulate matter (it doesn’t help chemical burn from gastric acid).
  • Secure airway to support oxygenation
  • PEEP to reduce shunt (??)
  • Bronchodilators to reduce wheezing.
  • Lidocaine to reduce neutrophil response.
  • Steroids probably don’t help.
  • Antibiotics are only indicated if the pt develops a fever or increased WBC count > 48 hours
15
Q

Pathology of flail chest:

A

consequence of blunt chest trauma with multiple rib fractures.
Paradoxical movement of the chest wall at the site of fractures.

INSPIRATION (neg intrathoracic pressure):
Normal chest wall moves outward and lungs inflate.
FC injured ribs move inward and collapse affected region.

EXPIRATION (pos intrathoracic pressure):
Normal chest wall moves inward and lungs empty.
FC injured ribs move outward and affected region doesn’t empty.

16
Q

Tx for flail chest:

A

epidural catheter or intercostal nerve blocks (higher risk of LA toxicity)

17
Q

Pulmonary HTN definition, causes, and goals:

A

Mean PAP > 25mmHg

Causes: COPD, Left side heart disease, connective tissue disorders

Goals: Optimize PVR

*pts with cor pulmonale (right heart failure) are also sensitive to increased PVR.

18
Q

Things that INCREASE Pulm vascular resistance:

A
Hypoxemia
Hypercarbia
Acidosis
SNS stimulation
Pain
Hypothermia

Increased intrathoracic pressure:
PEEP, Atelectasis, Mechanical ventilation.

Drugs:
Nitrous Oxide, Ketamine, Desflurane

19
Q

Things that DECREASE Pulm vascular resistance:

A

Increased PaO2
Hypocarbia
Alkalosis

Decreased intrathoracic pressure:

  • preventing coughing/straining
  • normal lung volumes
  • spontaneous ventilation
  • high frequency jet ventilation

Drugs:

  • inhaled Nitric Oxide
  • Nitroglycerin
  • Phosphodiesterase inhibitors (Sildenafil)
  • Prostaglandins (PGE1/PGI2)
  • CCB
  • ACE-I
20
Q

Pathophysiology of Carbon Monoxide Poisoning:

A
Reduces CaO2 (left shift)
Binds on O2 site on Hgb with x200 the affinity of O2.
Oxidative phosphorylation is impaired and metabolic acidosis results.
21
Q

Anesthetic considerations and treatment for carbon monoxide poisoning:

A
  • CO is measured with a Co-oximeter (NOT pulse ox)
  • pts appear cherry red (not cyanosis)
  • SNS stimulation maybe confused with light anesthesia or pain.
  • id soda lime is desiccated, then VA can produce CO (Des > Iso&raquo_space;> Sevo)

100% FiO2 until CoHgb is less than 5% or for 6hrs.
Hyperbaric oxygen if CoHgb > 25% or patient is symptomatic.

22
Q

Absolute Indications for one lung ventilation (OLV):

A

Isolation of One lung to avoid contamination (infection/massive hemorrhage)

Control of distribution of ventilation:

  • bronchopleural fistula
  • surgical opening of major airway
  • large unilateral lung cyst or bulla
  • life threatening hypoxemia r/t lung disease

Unilateral bronchopulmonary lavage (pulm alveolar proteinosis)

23
Q

Relative Indications for one lung ventilation (OLV):

A

Surgical exposure (high priority):

  • thoracic aortic aneurysm
  • pneumonectomy
  • thoracoscopy
  • upper lobectomy
  • mediastinal exposure

Surgical exposure (low priority):

  • middle and lower lobectomy
  • esophageal resection
  • thoracic spinal surgery

Pulmonary edema s/p CABG

Severe hypoxemia r/t lung disease

24
Q

How anesthesia in lateral position affects V/Q relationship:

A

Non-dependent lung becomes more compliant.

Dependent lung becomes less compliant and a reduction in alveolar volume contributes to atelectasis.

Perfusion is better DEPENDENT lung.
Ventilation is better in NONDEPENDENT lung.
This creates a mismatch and increase risk of hypoxemia during OLV.

25
Q

Management of Hypoxemia during one-lung ventilation:

A
  • 100% FiO2
  • Confirm DLT position (most common complication)
  • CPAP 10cmH2O to non-dependent non-ventilated lung
  • PEEP 5-10cmH2O to dependent ventilated lung
  • alveolar recruitment maneuver
  • clamp pulmonary artery to the non-dependent nonventilated lung
  • resume 2 lung ventilation
26
Q

Reason for performing mediastinoscopy:

A

done to obtain biopsy of the paratracheal lymph nodes at the level of the carina.
helps surgeon stage the tumor prior to lung resection.

27
Q

Complications of mediastinoscopy:

A
  • Hemorrhage (most common)
  • pneumothorax (2nd most common)
  • impaired cerebral perfusion d/t innominate artery compression
  • dysrhythmias d/t stimulation of carotid, aorta, or trachea
  • air embolism d/t venous injection and air entrainment
  • chylothorax d/t thoracic duct injury (left chest only)
  • hoarseness and/or vocal cord paralysis d/t RLN/vagus injury

*innominate artery compression compromises the circulation to the right upper extremity and right side of the circle of willis. place a-line/pulse ox on right side to monitor for compression.

28
Q

Describe Mallampatie score:

A

Mnemonic PUSH

CLASS 1: Pillars, Uvula, Soft palate, Hard palate
CLASS 2: _ Uvula, Soft palate, Hard palate
CLASS 3: _ _ Soft palate, Hard palate
CLASS 4: _ _ _ Hard palate

29
Q

Normal Inter-incisor gap:

A

2-3 finger breaths or 4 cm

30
Q

Thyromental distance:

A

Neck extended and mouth closed.
Measure from tip of thyroid cartilage to tip of the mentum.
DL maybe more difficult if the TMD is < 6 cm (3 finger breaths) or greater than 9 cm.

31
Q

Mandibular protrusion test:

A

Assesses the function of the temporomandibular joint.
Pt is asked to sublux the jaw. Position of lower incisors is compared to the upper incisors.

CLASS 1: can move Li past Ui and bite vermilion of lip
CLASS 2: can move Li in line with Ui
CLASS 3: can’t move Li past Ui (risk for difficult intubation)

32
Q

Conditions that impair Atlanta-occipital joint mobility:

A
Degenerative joint disease
Rheumatic arthritis
Ankylosing spondylitis
Trauma
Surgical fixation
Klippel-Feil
Down syndrome
33
Q

Cormack and Lehanne score:

A

GRADE 1: complete or nearly complete view of glottic opening.
GRADE 2: Posterior region of glottic opening.
GRADE 3: Epiglottis only.
GRADE 4: Soft palate only.

34
Q

5 risk factors for difficult mask ventilation:

A

BONES

Beard
Obese (BMI > 26)
No teeth
Elderly (age > 55)
Snoring
35
Q

10 risk factors for difficult intubation:

A
Small mouth opening 
Narrow palate with high arch
Long upper incisors
Interincisor distance < 3cm 
Mallampatie 3 or 4
Mandibular protrusion class 3
Poor compliance of submandibular space 
TMD < 6cm or > 9cm
Neck is thick and short
Poor AO joint mobility (can't touch chin to chest and/or can't extend the neck)
36
Q

6 risk factors for difficult supraglottic device placement

A

Limited mouth opening
Upper airway obstruction
Altered pharyngeal anatomy (prevents seal)
Poor airway compliance (requires excessive PIP)
Increased airway resistance (requires excessive PIP)
Lower airway obstruction

37
Q

5 risk factors for difficult invasive airway placement:

A
  • Abnormal neck anatomy (tumor, hematoma, abscess, h/o radiation)
  • Obesity (can’t ID cricothyroid membrane)
  • Short neck (can’t ID cricothyroid membrane)
  • Limited access to cricothryoid membrane (halo, neck flexion deformity)
  • Laryngeal trauma
38
Q

Angioedema definition:

A

result of increased vascular permeability that can lead to swelling of the face, tongue, and airway.

39
Q

Angioedema causes and tx:

A

ACE-I
Tx: Epinephrine, antihistamines, steroids (just like anaphylaxis)

Hereditary angioedema (C1 esterase deficiency)
Tx: C1 esterase concentrate or FFP
(not epinephrine, antihistamines, or steroids)

40
Q

Ludwig’s angina:

A

bacterial infection characterized by rapidly progressing cellulitis in the floor of the mouth. Inflammation and edema compress the submandibular, submaxillary, and sublingual spaces.

*most significant concern is posterior displacement of the tongue resulting in complete, supraglottic airway obstruction.

41
Q

Best way to secure the airway in Ludwig’s angina:

A

Awake nasal intubation

Awake tracheostomy

42
Q

Practice Guidelines for Preoperative Fasting and Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration

A

2 hours- clear liquids
4 hours- breast milk
6 hours- nonhuman milk, infant formula, solid food
8 hours- fried or fatty foods

*ingestion of clear liquids 2 hours before surgery reduces gastric volume and increases gastric pH

43
Q

Oropharyngeal airways

A
Guedel
Berman (what we used at BHMC)
Williams (for blind orotracheal intubation and fiberoptic intubations)
Ovassapian (for fiberoptic intubations)
44
Q

Best time to use an Eschmann introducer (gum elastic bougie):

A

when a grade 3 view is obtained during DL (grade 2 is the next best time).
likelihood of successful intubation is unacceptably low in grade 4 view.

45
Q

Contraindications to nasopharyngeal airway:

A

Cribriform plate injury:

  • LeFort 2 or 3 fx
  • Basilar skull fx
  • CSF rhinorrhea
  • Raccoon eyes
  • Periorbital edema

Coagulopathy
Previous transsphenoidal hypophysectomy
Previous Caldwell-Luc procedure
Nasal fx

*caution during pregnancy

46
Q

Maximum recommended cuff pressure for ETT:

A

< 25 cm H20

47
Q

Maximum recommended cuff pressure for LMA:

A

< 60 cm H20

48
Q

Maximum recommended peak inspiratory pressures for:
LMA- Unique
LMA- Proseal
LMA- Supreme

A

LMA- Unique < 20 cm H2O
LMA- Proseal < 30
LMA- Supreme < 30

49
Q
Largest size ETT that can pass through each LMA size:
LMA 1
1.5
2
2.5
3
4
5
A

LMA —pt size—-cuff mL—-ETT—-flexible endoscope
1——– <5kg————4———–3.5———–2.7
1.5——-5-10kg———7———–4.0———–3.0
2——– 10-20kg——10———–4.5———–3.5
2.5——20-30kg——14———–5.0———–4.0
3——– 30-50kg——20———-6.0———-5.0
4——– 50-70kg——30———–6.0———–5.0
5——– 70-100kg—–40———–7.0———–5.5

50
Q

5 indications for the Bullard laryngoscope:

A

(rigid, fiberoptic device used for indirect laryngoscopy.)

small mouth opening (min of 7mm)
impaired cervical spine mobility
short thick neck
teacher collins syndrome
Pierre-robin syndrome
51
Q

5 indications for the use of a bronchial blocker:

A

pts requiring lung separation who are:

< 8 years old (smallest DLT is 26F)
require nasal intubation
have tracheostomy
have a single lumen ETT in place
require intubation after surgery
52
Q

Uses for bronchial blocker:

A

It can insufflate O2 into the non-ventilated lung
Suction air from the non-ventilated lung (improve surgical exposure)

it CAN NOT be used to ventilate or suction blood, pus, secretions from non-ventilated lung

53
Q

2 indications for retrograde intubation:

A

unstable cervical spine (most common)
upper airway bleeding (can’t visualize glottis)

*since Ri requires ~5-7minutes for experienced practitioners, it is best used when intubation has failed but ventilation is still possible.

54
Q

Best time to use airway exchanger:

what can you do with it?

A

Most common device used to manage extubation of a difficult airway.

you can use it to:
measure ETCO2
jet ventilate via luer-lock adapter
oxygen insufflation via 15mm adapter

55
Q

Bohr Effect:

A

Says increased CO2 and Decreased pH cause erythrocyte to release O2.
(its the cells way of asking hgb to release O2 to support aerobic metabolism)

56
Q

Haldane effect:

A

Says increased O2 causes the erythrocyte to release CO2 (occurs in lungs).
(deoxygenated Hgb is able to carry more CO2)

57
Q

3 primary causes of Hypercapnia and examples:

A
  1. Increased CO2 production:
    - Sepsis
    - Overfeeding
    - MH
    - Intense shivering
    - Prolonged seizure activity
    - Thyroid storm
    - Burns
  2. Decreased CO2 elimination:
    - Airway obstruction
    - Increased DS
    - Increased Vd/Vt
    - ARDS
    - COPD
    - Respiratory center depression
    - Drug overdose
    - Inadequate NMB reversal
  3. Rebreathing:
    - Incompetent one-way valve
    - Exhausted soda lime
58
Q

4 areas in the respiratory center:

A

(located the brain stem [reticular activating system])

Pontine Respiratory center:

  • Pneumotaxic center (upper pons): inhibits DRC
  • Apneustic center (lower pons): stimulates DRC

Medullary Respiratory center:

  • Dorsal respiratory center: Activates during inspiration (inspiratory pacemaker)
  • Ventral respiratory center: Activates during expiration
59
Q

Central chemoreceptors:

A

Located in medulla.
Responds to H+ concnentration in CSF.
H+ in the CSF is a function of PaCO2 of the blood

60
Q

Peripheral chemoreceptors:

A

Located in carotid bodies: nerves of hiring –> glossopharyngeal (CN9)
Located in aortic arch: vagus (CN10)
Respond to decreased O2, increased CO2, and increased H+

61
Q

Which reflex prevents overinflation of the lungs?

A

Hering-Breuer inflation reflex.

Lung inflates > 1.5L–>CN10–>inspiratory off switch–>central respiratory activity–> phrenic n. (C3-5)–> inspiration stops

62
Q

What inhibits HPV?

A

Halogenated anesthetics >1-1.5MAC
Phosphodiesterase inhibitors
Dobutamine
Vasodilators

63
Q

Diffusing capacity for Carbon Monoxide:

A

Used to assess how well the lungs exchange gas.

Normal: 17-25mL/CO/min/mmHg

Using Fick’s law tells us:

  1. Surface area (decreased by emphysema
  2. Thickness (increased by pulm fibrosis and pulm edema)

Therefore, DLCO is reduced by anything that reduces alveolar surface area or increases the thickness of alveolar-capillary interface.