Ventilator Management

Question 1

Tidal Volume (Vt)

Answer 1

How much air the patient breathes in a normal breath.

(Excessive Vt can cause ventilator-induced lung injury)

Question 2

Inspiratory Reserve Volume (IRV)

Answer 2

The amount of air that can be forcefully inhaled in addition to a normal tidal volume breath

Question 3

Expiratory Reserve Volume (ERV)

Answer 3

The amount of air that can be forcefully exhaled after a normal tidal volume breath.

Question 4

Vital Capacity (VC)

Answer 4

Vt + IRV + ERV

Question 5

Residual Volume (RV)

Answer 5

The amount of air left in the respiratory tract following forceful exhalation.

Question 6

Total Lung Capacity (TLC)

Answer 6

IRV + Vt + ERV + RV

Question 7

Dead Space

Answer 7

The surfaces of the airway that are not involved in gas exchange

Dead Space = 2mL/kg

Question 8

Central Chemoreceptors

Answer 8

Located in the medulla/pons

Driven by CO2 and H+ levels

Question 9

Peripheral Chemoreceptors

Answer 9

Located in the aortic arch/carotid bodies

Response is driven by O2, CO2 and H+

Question 10

Fick Formula

Answer 10

Used to tell how much O2 a person is using. Cardiac ouput measurement based on the principle that oxygen uptake by the lungs equals oxygen delivery.

Question 11

V/Q Scan

Answer 11

Nuclear medicine study used to evaluate circulation of air and blood within the lungs to determine the V/Q ratio.

Question 12

Hypercarbic Respiratory Failure

Answer 12

Inability to remove CO2

Indicated By - Respiratory Acidosis

Treatment - Increased Vt then rate

Question 13

Hypoxic Respiratory Failure

Answer 13

Inability to Diffuse CO2

Indication - Low PaO2

Treatment - Increased Vt, O2 concentration, then rate

Question 14

Apneustic Breathing

Answer 14

Abnormal breathing pattern characterized by a deep, gasping inspiration with a pause at full inspiration, followed by a brief, insufficient release.

(Associated with decerebrate posturing)

Question 15

Ataxic Respirations

Answer 15

Abnormal pattern of breathing characterized by compolete irregularity of breating, with irregular pauses and increasing periods of apnea.

(Caused by damage to the medulla)

Question 16

Biots Breathing

Answer 16

Abnormal pattern of breathing characterized by groups of quick, shallow inspirations followed by regular or irregular periods of apnea.

Question 17

Cheyne-Stokes Respirations

Answer 17

Progressively deeper and sometimes faster breathing, followed by a gradual decrease that results in temporary apnea.

(Brainstem herniation, decorticate posturing)

Question 18

Kussmaul’s Respirations

Answer 18

Respirations gradually become deep, labored and gasping. Associated with DKA.

Question 19

Controlled

Answer 19

The patient’s breathing rate (F) and tidal volume (Vt) is controlled completely.

Question 20

Intermittent

Answer 20

The patient can take intermittent breaths (between the controlled breaths).

Question 21

Synchronized

Answer 21

The ventilator synchronizes delivery of breath with the patient’s inspiratory drive.

Question 22

Assist

Answer 22

The ventilator assists the patient with their breathing (must have intact respiratory drive).

Question 23

Ventilator Acquired Pneumonia (VAP)

Answer 23

1 cause of iatrogenic death in the US

Question 24

Curare Cleft

Answer 24

Tick marks seen on capnography, patient is choking. Check ETT. Patient needs to be resedated and reparalyzed.

Question 25

Tidal Volume (Vt) Setting

Answer 25

6-8mL/kg

Question 26

F (Rate)

Answer 26

8-20 breaths/min

Question 27

Minute Volume (Ve)

Answer 27

F x Vt (4-8 L/min)

Question 28

Inspiratory: Expiratory Ratio (I:E)

Answer 28

1:2

Question 29

Fraction of Inspired Oxygen (FiO2)

Answer 29

0.21-1.0

Question 30

Plateau Pressure (Pplat)

Answer 30

\< 30 - respresents the static ensd inspiratory recoil pressure of the respiratory system, lung and chest wall respectively.

Question 31

Positive End Expiratory Pressure (PEEP)

Answer 31

Keeps alveoli so that oxygen can diffuse, prevents atalectasis.

Question 32

Peak Expiratory Flow Rate (PEFR)

Answer 32

500 to 700 L/min for males, 380 to 500 L/min for females. A person's maximum speed of expiration, as measured with a peak flow meter.

Question 33

Controlled Mandatory Ventilation (CMV)

Answer 33

* Used in sedated, apneic or paralyzed patients * All breaths are triggered, limited, and cycled by the ventilator * Patient has no ability to initiate own breaths

Question 34

Synchronized Intermittent Mandatory Ventilation (SIMV)

Answer 34

* Assisted mechanical ventilation synchornized with the patient's breathing * Ventilator senses the patient taking a breath, then delivers a breath. * Spontaneous breathing by the patient occurs between the assisted breaths which occur at preset intervals * Preferred in patients with an intact respiratory drive

Question 35

Assist-Control Ventilation (AC)

Answer 35

* The trigger for delivery of a breath can be either the patient or elapsed time * Ventilator supports every breath, whether it's initiated by the patient or the ventilator * Used in ARDS, paralyzed or sedated patients * Anxious Patient - can breath-stack/auto-PEEP - Can cause VILI

Question 36

Pressure Support Ventilation (PSV)

Answer 36

* Makes it easier for the patient to overcome the resistance of the ETT and is used during weaning * Reduces work of breathing * Patient determines tidal volumes, rate (minute volume) * Requires consistent ventilatory effort by the patient

Question 37

CPAP/BIPAP

Answer 37

Similar to SIMV because they are all spontaneously triggered by the patient

Question 38

CPAP

Answer 38

The use of continuous positive pressure to maintain a continuous level of PEEP. Mild air pressure to keep an airway open.

Question 39

BiPAP

Answer 39

Uses alternating levels of PEEP to maintain oxygenation, commonly used in pneumonia, COPD, asthma, etc.

Question 40

Low Pressure Alarm Causes

Answer 40

* Patient disconnection from machine * Chest tube leaks * Circuit Leak * Airway Leak * Hypovolemia

Question 41

High Pressure Alarm Causes

Answer 41

* Kinked Line * Coughing * Secretions * Patient biting the tube * Reduced lung compliance * Increased Airway Resistance

Question 42

DOPE Mnemonic

Answer 42

Displacement Obstruction Pneumothorax Equipment

Question 43

"Blue Bloaters"

Answer 43

COPD patients with chornic bronchitis

Question 44

"Pink Puffers"

Answer 44

COPD patients with emphysema. Color is pink due to polycythemia vera.

Question 45

COPD CXR Findings

Answer 45

Flattened diaphragm, chest cavity is over expanded due to air trapping.

Question 46

Pneumonia

Answer 46

* Often viral, sometimes bacterial * CXR shows pleural effusions, lobar consolidation * Right middle lobe pneumonia is most common site

Question 47

ARDS

Answer 47

Acute Respiratory Distress Syndrome * CXR - ground glass appearance, patchy infiltrates, bilateral diffuse infiltrates * Swann-Ganz - increased PAWP (high pressure because right heart is pumping against increased pressure in the lung vasculature) * Tx: High PEEP, High Vt