Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pulm > Lecture 7: Respiratory Failure > Flashcards

Lecture 7: Respiratory Failure Flashcards

1
Q

What does an ABG measure?

A
  • PaO2 (Oxygen tension)
  • SaO2 (Oxyhemoglobin saturation)
  • PaCO2 (CO2 tension)
  • pH
  • HCO3 (Bicarb concentration)

Additional tests cinlude methemoglobin, carboxyhemoglobin, and hemoglobin levels.

The little a means arterial, whereas a big A means alveolar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What wrist test is used to test for ABG viability?

A

Modified allen test, which checks for collateral circulation of the radial and ulnar arteries.

Only checking patency of ulnar side, normal is both sides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are CIs to ABG?

A
  • Severe PAD in wrist
  • Active Raynaud’s
  • Failure of modified allen test
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is SaO2?

A

Proportion of RBCs with hemoglobin bound to O2.

Pulse ox measurement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the preferred measurement to look at for ventilation?

A
  • Ventilation is best marked by PaCO2.
  • Oxygenation is best marked by PaO2.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 causes of an increased A-a gradient?

A
  • V/Q mismatch
  • Shunt
  • Impaired diffusion

Helps to determine the cause of hypoxemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What could result in hypoxemia even if the A-a gradient is normal?

A
  • Hypoventilation
  • Low inspired O2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What measurement in an ABG suggests respiratory acidosis? Alkalosis?

A
  • Acidosis: PaCO2 > 45
  • Alkalosis: PaCO2 < 35
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Determine the acid-base disorder currently present.

pH = 7.32
PaCO2 = 52
HCO3 = 19

A

Mixed acidosis

No compensation present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Determine the acid-base disorder currently present.

pH = 7.34
PaCO2 = 50
HCO3 = 31

A

Respiratory acidosis with incomplete compensation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Determine the acid-base disorder currently present.

pH = 7.38
PaCO2 = 24
HCO3 = 19

A

Metabolic acidosis with complete compensation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Determine the acid-base disorder currently present.

pH = 7.46
PaCO2 = 42
HCO3 = 31

A

Metabolic alkalosis with incomplete compensation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Determine the acid-base disorder currently present.

pH = 7.39
PaCO2 = 41
HCO3 = 25

A

Normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Determine the acid-base disorder currently present.

pH = 7.42
PaCO2 = 51
HCO3 = 33

A

Metabolic alkalosis with complete compensation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the primary causes of respiratory acidosis?

A
  • Airway obstruction
  • Lung disease
  • Chest wall disease
  • Neuromuscular disease
  • Primary brain injury

Things causing you to not breathe out enough.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the primary causes of respiratory alkalosis?

A
  • Voluntary hyperventilation
  • Involuntary hyperventilation (anxiety, asthma exacerbation, CNS disease)
  • Lung disease resulting in hyperventilation (PE)

Things causing you to breathe out too much CO2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 3 primary etiologies for metabolic acidosis?

A
  1. Bicarb loss
  2. Increased acid load
  3. Impaired acid excretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does elevated anion gap imply?

A

There are anions that we cannot measure.

= Na + K - (HCO3 + Cl)

Examples: lactic acidosis, ketoacidosis, acute renal failure, and toxic acids.

Normal gap is typically < 12.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is MUDPILES?

A
  1. Methanol
  2. Uremia (BUN > 60)
  3. DKA
  4. Paracetamol (Acetaminophen)
  5. Isoniazid, Iron
  6. Lactic acidosis
  7. Ethylene glycol
  8. Salicylates (ASA)

Causes of anion gap metabolic acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If there is no anion gap present, what are the most likely etiologies?

A
  • Diarrhea
  • Renal tubular acidosis

Loss of bicarb or decreased H+ excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the 3 primary etiologies for metabolic alkalosis?

A
  • Volume contraction (losing fluid that mostly has Na in it)
  • Loss of HCl
  • Hypokalemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What characterizes acute lung injury? (ALI)

A

Acute, severe hypoxia with a non cardiogenic cause.

ARDS is the most severe form of an ALI.

Usually due to non-cardiogenic pulmonary edema. (AKA not pulmonary edema 2/2 HF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the most common cause of ARDS?

A

Sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the pathologic hallmark of ARDS?

A

Diffuse, alveolar damage due to pro-inflammatory cytokines.

Pathognonomic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the pathophysiological effects of ARDS on lung interstitium and alveoli.

A
  1. Excess fluid accumulates in both interstitium and alveoli.
  2. Impaired gas exchange
  3. Decreased compliance
  4. Increased pulmonary arterial pressure
  5. Reduction in production of surfactant.

Surfactant reduces surface tension.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the diagnostic criteria for ARDS?

A
  1. Acute onset within 1 week of clinical insult
  2. Bilateral pulmonary infiltrates (r/o PNA)
  3. Respiratory failure not fully explained by HF or volume overload.
  4. PaO2/FiO2 ratio < 300 mm Hg

Normal FiO2 is around 21%.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What determines ARDS severity?

A
  1. Mild = PaO2/FiO2 ratio is 200-300 mm Hg
  2. Mod = PaO2/FiO2 ratio is 100-200 mm Hg
  3. Severe = PaO2/FiO2 ratio < 100 mm Hg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the clinical findings often associated with ARDS?

A
  • SOB, tachypnea, intercostal retractions and crackles.
  • Marked hypoxemia
  • Multiple organ failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What do CXRs tend to show for ARDS?

A
  • Diffuse or patchy bilateral infiltrates that spare the costophrenic angles.
  • Heart size should be normal w/ no effusions.
  • Air bronchograms in 80% of patients. (Not diagnostic)
30
Q

What is the treatment for ARDS?

A
  • Treating the underlying condition that led to ARDS.
  • Treat any secondary condition (such as sepsis)
  • Supportive care
31
Q

What is the treatment for hypoxemia 2/2 ARDS?

A
  • Ventilator
  • Supplemental O2 to maintain PaO2 > 55 mm Hg.
  • Keep FiO2 < 60% to prevent O2 toxicity.
32
Q

What is PEEP and what is it used for?

A
  • Positive end-expiratory pressure
  • Prevents alveolar collapse

Ideally, lowest PEEP possible that is effective.

33
Q

What can auto-PEEP lead to?

A
  • Decreased venous return
  • Reduced cardiac output
  • Hypotension

If we keep building pressure within our chest, then we have a smaller pressure gradient between our chest and our heart, so less venous return.

Improves hemodynamic outcomes but not mortality.

34
Q

What is prone positioning and what is the purpose?

A

Laying flat will shift the lungs, recruiting different alveoli and making the heart press less against the left lung.

35
Q

What is the only treatment that has been shown to reduce mortality in ARDS?

A

Volume controlled ventilation with low tidal volume ventilation (LTVV)

Prevents alveoli from overexpanding

Can result in permissive hypercapnia

36
Q

What is respiratory failure in a nutshell?

A

Inability of the lungs to meet the metabolic demands of the body.

37
Q

What is Type 1 respiratory failure?

A

Lungs fail to provide adequate oxygenation of the blood (PaO2 < 60 mm Hg)

Hypoxemic respiratory failure, also the MC.

Oxygenation is impaired, but ventilation is normal.

38
Q

What are the causes of hypoxemic respiratory failure?

A
  • Decreased inspired O2 tension (PIO2)
  • V/Q mismatch (COPD)
  • Diffusion limitation (Fibrosis)
  • Intrapulmonary shunts (PNA, atelectasis, CHF, ARDS)
  • Heart/Lung/Blood disorders

PIO2 is partial pressure of inspired oxygen, which decreases in high altitudes. (thinner air)

39
Q

What do focal infiltrates on a CXR + hypoxemic respiratory failure suggest for etiologies?

A
  • Atelectasis
  • Pneumonia
40
Q

What do diffuse infiltrates on CXR + hypoxemic respiratory failure suggest for etiologies?

A
  • Cardiogenic pulmonary edema
  • Non-cardiogenic pulmonary edema
  • Interstitial PNA or fibrosis
  • Infectious (bilateral PNA)
41
Q

What is type 2 respiratory failure?

A
  • Defect in ventilation, AKA inability to eliminate CO2 properly.
  • PaCO2 > 50 mm Hg
  • Hypercapnic respiratory failure

Also hypoxemic, but PaCO2 is far more elevated.

pH is variable due to bicarb buffering.

42
Q

What are the primary causes of hypercapnic respiratory failure?

A
  • Respiratory center dysfunction (medulla)
  • Drug OD, CVA, tumor
  • Central hypoventilation
  • Neuromuscular diseases (polio, myasthenia gravis, spinal injuries, GBS)
  • Chest wall/pleural diseases
  • Upper airway obstruction
  • Peripheral airway disorder

GBS = guillain barre syndrome

43
Q

What is acute on chronic respiratory failure?

A

A patient with chronic CO2 retention acutely worsens, resulting in rising CO2 and low pH.

Acute hypercapnic respiratory failure

Arterial pH is often low.

44
Q

What are the slight differences between hypoxemia vs hypercapnia?

A
  • HA in hypercapnia
  • Hyperemia in hypercapnia
  • Papilledema & asterixis in hypercapnia

Both share dyspnea, tachycardia, tachypnea, and HTN.

Asterixis is a flapping tremor of the hand.

45
Q

What is the primary goal in treating acute hypoxemic respiratory failure?

A

Adequate oxygenation > 90% SaO2 or PaO2 >= 60 mm Hg.

Do not withhold oxygen for fear of progressive respiratory acidosis.

46
Q

For every liter increase in O2, how much does FiO2 tend to increase?

A

Approximately 4%

2L of O2 starts at around 28% FiO2.

Normal air is 21% FiO2.

47
Q

For a simple face mask, what is the preferred flow rates and why?

A
  • 5-8 L/min
  • Going under 5L/min can cause the patient to rebreathe too much of their own air.

Has vents on the side, unlike a NRB.

Should only be used short term.
Often used in type 1, hypoxemic respiratory failure.

48
Q

What is the main benefit of a partial rebreather mask over a simple mask?

A
  • Increases FiO2 by recycling expired O2.
  • O2 reservoir bag used to recycle dead space air.
49
Q

How high does FiO2 go up to for a NRB?

A

95%

50
Q

What are the one-way valves in a NRB used for?

A
  • Entrance of room air during inspiration
  • Retention of exhaled gases during expiration.
51
Q

What is the primary benefit of a Venturi mask?

A

It can mix RA and oxygen to dial in FiO2 more precisely.

52
Q

What oxygen delivery method would be good for a patient that cannot wear a mask or nasal cannula?

A

Face tent

53
Q

What is the oxygen delivery method for babies?

A

Oxygen hood.

54
Q

What is the first line therapy for COPD patients with hypercapnic respiratory failure and can tolerate a BPAP?

A

Noninvasive positive pressure ventilation. (NPPV)

Pressure ventilation.

Patient must be able to protect their own airway, handle their own secretions, and tolerate a BPAP mask.

55
Q

What is BPAP?

A

Bilevel positive airway pressure, which delivers preset inspiration and expiration positive airway pressure. (IPAP and EPAP)

Essentially, it augments their breathing, but they still breathe on their own.

BPAP = booster

56
Q

What is CPAP?

A
  • Continuous positive airway pressure, mainly for sleep apnea.
  • No additional pressure above CPAP level.

Patient must be able to initiate breathing on their own.

57
Q

When is intubation indicated?

A
  • Hypoxemia despite supplemental O2
  • Upper airway obstruction
  • Unable to protect airway or clear secretions
  • Acute hypercapnia that does not respond quickly to NPPV
  • Progressive fatigue, AMS, weakness
  • Apnea
58
Q

What is the preferred method of intubation?

A

Orotracheal

59
Q

Describe what should be done when first initiating orotracheal intubation.

A
  • Auscultate both lungs to verify ventilation.
  • Verify that ET tube is at the level of the aortic arch.
  • Cuff pressure should be under 20 mm Hg
60
Q

What are the two types of breaths in mechanical ventilation?

A
  • Ventilator-initiated based on a timer.
  • Patient-initiated, in which ventilator detects flow change and assists breath.
61
Q

What is a volume assist breath?

A

Patient initiates, and ventilator provides assistance until set TV is met.

62
Q

What is a volume control breath?

A

Ventilator initiated and terminated once set TV is reached.

63
Q

What is continuous mandatory ventilation mode?

A

Minute ventilation is determined entirely by set RR and TV.

No additional patient effort required.

Most controlled form of mechanical ventilation.

64
Q

What is intermittent mandatory ventilation mode?

A
  • Minimum ventilation set by TV and RR.
  • Patient can increase the minute ventilation by spontaneously breathing as well.

Ensures patient breathes at a minimum.

65
Q

What is synchronized IMV mode?

A

Ventilator will sync with patient effort, preserving better respiratory muscle.

66
Q

What is pressure support ventilation mode?

A
  • Patient triggers each breath.
  • Ventilator simply adjusts the pressure of each breath.

Often used to wean a patient off mechanical ventilation.

Patient needs to provide enough effort to ensure adequate minute ventilation.

67
Q

What is the common PEEP setting and its purpose?

A
  • Commonly set at 5 cm H2O.
  • Prevent alveolar collapse during end expiration.
68
Q

What are the complications of mechanical ventilation?

A
  • Barotrauma (too much TV or PEEP)
  • VAP
  • Trauma (tracheal stenosis, vocal cord dysfunction)

VAP increases by 1% for everyday on a vent ):

Barotrauma includes pneumothorax, subQ emphysema, and pneumomediastinum.

69
Q

What is used to determine lung transplant eligibility?

A

Lung allocation score

Re-evaluated every 3 months.

70
Q

What infections relatively disqualify someone from lung transplant eligibility?

A

Hep B, C, or HIV

Relative contraindications now.

Pulm (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions