quiz 5 Flashcards by Ezekiel McGinn

What does the P(a-ET)CO2 tell us?

The difference between arterial CO2 and end tidal CO2
Increases in the difference indicate an increase in deadspace

How well did you know this?

Not at all

Perfectly

What can cause dead space?

PE
Loss of circulation
COPD
Being dead (cardiac arrest)

How well did you know this?

Not at all

Perfectly

What is dead space?

Ventilation without perfusion

How well did you know this?

Not at all

Perfectly

How do you determine the ratio of deadspace to tidal volume

VD/VT ratio

How well did you know this?

Not at all

Perfectly

What is the formula for the VD/VT ratio?

PaCO2 - PeTCO2 / PaCO2

How well did you know this?

Not at all

Perfectly

What is a normal VD/VT ratio?

.2-.4

How well did you know this?

Not at all

Perfectly

What does an elevated VD/VT ratio mean?

An increased amount of deadspace

How well did you know this?

Not at all

Perfectly

What can cause respiratory acidosis?

Parenchymal lung disease
Airway disease
Pleural abnormalities
Chest wall abnormalities
Neuromuscular disorders
CNS depressing

How well did you know this?

Not at all

Perfectly

What are the diagnostic benchmarks for determining respiratory acidosis?

pH < 7.35
PaCO2 > 45 mmHg

How well did you know this?

Not at all

Perfectly

What is the formula to determine an appropriate tidal volume for a patient on a vent with respiratory acidosis?

Desired VT = (known PaCO2 x Known VT) / Desired PaCO2

How well did you know this?

Not at all

Perfectly

What is the formula for determining an appropriate RR with a patient on a vent with respiratory acidosis?

Desired RR = (Known PaCO2 x Known RR) / Desired PaCO2

How well did you know this?

Not at all

Perfectly

What is the risk of a high respiratory rate?

autoPEEP

How well did you know this?

Not at all

Perfectly

How can you determine if a patient has autopeep?

On exhalation, flow will not return to zero before a new breath is given

How well did you know this?

Not at all

Perfectly

What can cause respiratory alkalosis?

Metabolic problems
Hypoxia
Medications
CNS disorders

How well did you know this?

Not at all

Perfectly

What are the diagnostic benchmarks for diagnosing respiratory alkalosis?

pH > 7.45
PaCO2 < 35 mmHg

How well did you know this?

Not at all

Perfectly

What are the most common causes of respiratory alkalosis in vented patients?

hyperventilation …..oops
Pain
Fever
Asynchrony
Hypoxemia

How well did you know this?

Not at all

Perfectly

What are the diagnostic benchmarks for determining if someone has metabolic alkalosis?

pH > 7.45
HCO3 > 26 mEq/L

How well did you know this?

Not at all

Perfectly

What are the diagnostic benchmarks for determining if someone has metabolic acidosis?

pH < 7.35
HCO3 < 22 mEq/L

How well did you know this?

Not at all

Perfectly

What can cause a metabolic acidosis?

Ketoacidosis
Loss of bicarb (diarrhea)
Medications
Lactic acidosis
Toxins

How well did you know this?

Not at all

Perfectly

What can cause a metabolic acidosis?

Loss of gastric fluid (vomiting, NG suctioning)
Diuretics
Medications

How well did you know this?

Not at all

Perfectly

Will a patient with metabolic alkalosis become apneic?

Apparently not

How well did you know this?

Not at all

Perfectly

What are some indications for suctioning?

Patients has a weak cough
Changes in waveform
Deterioration of oxygen saturation

How well did you know this?

Not at all

Perfectly

What is the formula for determining the correct suction catheter size?

(ETT size x 3) / 2

How well did you know this?

Not at all

Perfectly

What is the appropriate suction pressure for adults?

-100 to -120 mmHg

What is the appropriate suction pressure for children?

-80 to -100 mmHg

What is the appropriate suction pressures for infants?

-60 to -100 mmHg

What are some potential complications from suctioning?

Your patient hating you Atelectasis Hypoxemia Loss of PEEP Cardiac arrhythmias Bradycardia hypo/hypertension Infection

T/F: For a patient on a vent, a SVN is more effective than an MDI with a spacer

False. MDIs with a spacer have been shown to be more effective than SVNs

What should be considered when giving an MDI through a vent?

Whether or not an HME is being used as it will take the medication out before it reaches the patient

What are some indications for bronchoscopy?

Presence of lesions Evaluation of atelectasis or pulmonary infiltrates Assess upper airway patency Suspicious sputum cytologic results

What are contraindications for a bronchoscopy?

Hemodynamic instability Poor oxygenation

When performing a bronchoscopy, what piece of equipment should be used to maintain PEEP?

No fucking clue, slides call it a PEEP keep. Probably just need to know that you need something special to maintain PEEP

What is normal urine production?

50-60 ml/hour 1 ml/kg/hour

What is the term for low urine output?

Oliguria

What is the term for high urine output?

Polyuria

What are the 5 drivers of hypoxemia?

Low oxygen tension of inspired gas Alveolar hypoventilation Diffusion defect V/Q mismatch Shunting

T/F: Healthy individuals have a natural V/Q mismatch

True. the apical sections of the lungs will have more ventilation and less perfusion than the bases which will have more perfusion and less ventilation

What is the most common cause of hypoxemia?

V/Q mismatch

What is a shunt?

Blood that does not participate in gas exchange either because of anatomical layouts or unventilated alveoli

What is ficks law?

Vgas = A/T x Dgas(P1-P2) Vgas = volume of gas diffusing across a membrane A = Surface area tension T = thickness of the membrane Dgas = diffusibility of the gas (solubility coefficient) P1-P2 = pressure gradient

What is circulatory hypoxia?

Hypoxia caused by not having enough blood in circulation Primarily caused by vampires

What is anemic hypoxia?

When you have enough blood (for now) but insufficient red blood cells in the blood

What is histoxic hypocia?

An excellent band name When you have sufficient blood and RBCs, but for some reason tissues are unable to use the oxygen

What are the two main tools we have to combat hypoxia?

Supplemental oxygen PEEP

What settings on the ventilator control ventilation?

Control variable Rate

What settings on the ventilator control oxygenation?

PEEP FiO2

List some reactive oxygen species

Superoxide ions (O2-) Hydrogen peroxide (H2O2) Hydroxyl ions (OH-)

What can large amounts of reactive oxygen species do to the body?

Damage lung tissue Disrupt cell signaling Break strands of DNA

What can hyperoxia cause?

Systemic vasoconstriction Pulmonary vasodilation Inflammation Oxidative stress on pulmonary, cardiovascular and neurological systems Create ROS

What is the normal partial pressure of oxygen in arterial blood?

80-100 mmHg

What is the normal partial pressure of oxygen in venous blood?

40 mmHg

What is the range of the partial pressure of oxygen in the alveoli when on room air and when on 100% oxygen?

100-673 mmHg

What is the oxygen content of mixed venous blood?

15 vol%

What is the normal saturation for mixed venous blood? 75%

75%

What is the oxygen content of arterial blood?

20 vol%

What is normal oxygen delivery? (DO2)

1000 mL/m

What is normal oxygen consumption?

250 ml/min

What are the main goals for oxygenation?

Maintain a PaO2 of 60-90 mmHg Try to keep FiO2 below 0.5-0.6 Maintain CaO2 at 20 mg/dL

What are the main dangers of prolonged high FiO2?

Oxygen toxicity Absorption atelectasis