S2 Ch 2 Pulm 3-3

Front 1

479. Acceptable ranges of gas values on ABG after initiating mechanical ventilation (Pao2, PaCo2, pH)?

Back 1

a. PaO2 of 50-60
b. With
c. PaCo2 of 40-50
d. And
e. pH between 7.35-7.50

Front 2

480. General principles of mechanical ventilation?

Back 2

a. Initial settings should rest the respiratory muscles
b. The goal is to reduce the likelihood of barotrauma (high static airway pressures, overinflation)
c. And
d. Atelectasis (low static airway pressures, underinflation).
e. A volume-cycled ventilator is most commonly used.

Front 3

481. 4 types of ventilator settings (just to prep)?

Back 3

1. Assisted controlled (AC) ventilation
2. Synchronous Intermittent Mandatory Ventilation (SIMV)
3. Continuous Positive Airway Pressure (CPAP)
4. Pressure-Support Ventilation (PSV)

Front 4

482. Assisted controlled (AC) ventilation?

Back 4

a. This is the initial mode used in most patients with respiratory failure
b. Guarantees a “backup” minute ventilation that has been preset
c. The ventilator delivers a breath (a predetermined tidal volume) when the patient initiates a breath.
d. If the patient does not initiate a breath, then ventilator takes control and delivers of breath at a predetermined rate.
e. In other words, the patient can go “over” the determined rate, but not under it.
f. And every breath over the determined rate delivers the SAME PREDETERMINED TIDAL VOLUME!
g. All breaths delivered by the ventilator (in contrast to intermittent mandatory ventilation)

Front 5

483. Synchronous Intermittent Mandatory Ventilation (SIMV)?

Back 5

a. Patients can breathe on their own above the mandatory rate WITHOUT help from the ventilator (i.e., the title volume of the extra breaths is NOT determined why the ventilator, as it is an assisted controlled mode).
b. When patient breathe spontaneously, there is no preset volume of breath that is triggered; but he or she still gets a guaranteed predetermined rate.
c. This method delivers the mandatory breath in synchrony with the patient's initiated spontaneous breath so that the 2 do not overlap, which is possible intermittent mandatory ventilation alone, hence “synchronous”.
d. If no spontaneous breath initiated by the patient, the predetermined mandatory breath is delivered by the ventilator.

Front 6

484. For what is Synchronous Intermittent Mandatory Ventilation (SIMV) appropriate?

Back 6

a. This is the appropriate mode for both support of ventilation and weaning.

Front 7

485. Continuous Positive Airway Pressure (CPAP)?

Back 7

a. Positive pressure (0-20 cm H2O) is delivered continuously (during inspiration and expiration) by the ventilator, but no volume breaths are delivered (patient breathe on his own)
b. The only parameter to set are PEEP and pressure support.
c. If the patient is being weaned, one can use CPAP to assess whether the patient is ready to be extubated.

Front 8

486. Pressure-support ventilation (PSV)?

Back 8

a. This is mostly used during trials.
b. Pressure is delivered with an initiated breath to assist breathing (pressure is NOT continuous- only responds to initiated breath).
c. It enhances respiratory efforts made by the patient.
d. PEEP may be added.

Front 9

487. Note: In general, err on the side of caution when deciding whether to initiate mechanical ventilation. Intubation does not mean the patient will have to remain on the ventilator indefinitely.

Back 9

487. Note: In general, err on the side of caution when deciding whether to initiate mechanical ventilation. Intubation does not mean the patient will have to remain on the ventilator indefinitely.

Front 10

488. On CXR, where should the tip of the ET tube be located?

Back 10

a. Approximately 3-5 cm above the carina.

Front 11

489. Parameters to consider in extubation or weaning from the ventilator? The more criteria that are met, the more likely that extubation will be tolerated:

Back 11

a. Whether the patient has an adequate respiratory drive
b. Intact cough (when suctioning secretions)
c. PaO2 >75, PaCO2 <45
d. O2 saturation >90% with PEEP of 5 cm H20 or less and FIO2 <40-50%.
e. Tidal volume > 5mL/kg
f. RR <30 breaths/min
g. Vital capacity >10-15 mL/kg
h. Negative inspiratory pressure <-20 cm H2O or more negative.

Front 12

490. 4 key parameters with mechanical ventilation (just to prep)?

Back 12

1. Minute ventilation (RR x VT)
2. FIO2
3. Inspiratory/expiration ratio (I:E ratio)
4. PEEP

Front 13

491. Minute Ventilation?

Back 13

a. (RR x VT)
b. This should be adjusted to achieve the patient's baseline PaCO2

Front 14

492. What is an appropriate initial tidal volume (VT) on ventilator in most cases and how should it vary for ARDS and COPD?

Back 14

a. Initial title volume (VT) of 8-10 mL/kg is appropriate in most cases (lower tidal volumes are recommended in patients with ARDS and COPD)

Front 15

493. Appropriate number of breaths for ventilator?

Back 15

a. A rate of 10 to 12 breaths per minute is appropriate

Front 16

494. What should the initial FIO2 be on ventilator and how should you proceed?

Back 16

a. 100%.
b. Quickly titrate down and use the lowest possible FIO2 to maintain a PaO2 of 50 to 60 or higher (or saturation >90%) to avoid oxygen toxicity

Front 17

495. What is a generally safe FIO2 value?

Back 17

a. FIO2 of less than 60% is generally safe.

Front 18

496. What should you do if you do if an FIO2 of 0.5 does not result in adequate PaO2?

Back 18

a. Add either PEEP or CPAP, both of which allow one to reduce FIO2 (i.e., to support PaO2 at a lower FIO2).

Front 19

497. What is the Inspiratory/expiratory ratio (I:E ratio)?

Back 19

a. The I:E ratio is the duration of time allotted to inspiration compared with the time allotted to expiration in one delivered breath.
b. Remember that the duration of each breath is determined by the set respiratory rate.
c. Therefore, increasing the time spent in inspiration will proportionately ↓ the time spent in expiration, and vice versa.
d. 1:2 is the usual ratio used.

Front 20

498. PEEP?

Back 20

a. PEEP is a positive pressure maintained the end of a passive exhalation-keeps the alveoli open.
b. It can be added to any mode of ventilation; used mostly in patients with hypoxic respiratory failure (ARDS).

Front 21

489. Parameters to consider in extubation or weaning from the ventilator? The more criteria that are met, the more likely that extubation will be tolerated:

Back 21

a. Whether the patient has an adequate respiratory drive
b. Intact cough (when suctioning secretions)
c. PaO2 >75, PaCO2 <45
d. O2 saturation >90% with PEEP of 5 cm H20 or less and FIO2 <40-50%.
e. Tidal volume > 5mL/kg
f. RR <30 breaths/min
g. Vital capacity >10-15 mL/kg
h. Negative inspiratory pressure <-20 cm H2O or more negative.

Front 22

490. 4 key parameters with mechanical ventilation (just to prep)?

Back 22

1. Minute ventilation (RR x VT)
2. FIO2
3. Inspiratory/expiration ratio (I:E ratio)
4. PEEP

Front 23

491. Minute Ventilation?

Back 23

a. (RR x VT)
b. This should be adjusted to achieve the patient's baseline PaCO2

Front 24

492. What is an appropriate initial tidal volume (VT) on ventilator in most cases and how should it vary for ARDS and COPD?

Back 24

a. Initial title volume (VT) of 8-10 mL/kg is appropriate in most cases (lower tidal volumes are recommended in patients with ARDS and COPD)

Front 25

493. Appropriate number of breaths for ventilator?

Back 25

a. A rate of 10 to 12 breaths per minute is appropriate

Front 26

494. What should the initial FIO2 be on ventilator and how should you proceed?

Back 26

a. 100%.
b. Quickly titrate down and use the lowest possible FIO2 to maintain a PaO2 of 50 to 60 or higher (or saturation >90%) to avoid oxygen toxicity

Front 27

495. What is a generally safe FIO2 value?

Back 27

a. FIO2 of less than 60% is generally safe.

Front 28

496. What should you do if you do if an FIO2 of 0.5 does not result in adequate PaO2?

Back 28

a. Add either PEEP or CPAP, both of which allow one to reduce FIO2 (i.e., to support PaO2 at a lower FIO2).

Front 29

497. What is the Inspiratory/expiratory ratio (I:E ratio)?

Back 29

a. The I:E ratio is the duration of time allotted to inspiration compared with the time allotted to expiration in one delivered breath.
b. Remember that the duration of each breath is determined by the set respiratory rate.
c. Therefore, increasing the time spent in inspiration will proportionately ↓ the time spent in expiration, and vice versa.
d. 1:2 is the usual ratio used.

Front 30

498. PEEP?

Back 30

a. PEEP is a positive pressure maintained the end of a passive exhalation-keeps the alveoli open.
b. It can be added to any mode of ventilation; used mostly in patients with hypoxic respiratory failure (ARDS).