Test 4

Question 1

pH

Answer 1

is a measure of the arterial blood’s hydrogen ion concentration and can reveal an acidic or alkalotic condition that can be the result of respiratory or metabolic abnormalities.

Question 2

PaCO2

Answer 2

is a measure of arterial carbon dioxide and is an important indicator of the adequacy of ventilation.

Question 3

HCO2

Answer 3

is hydrogen bicarbonite, or bicarbinate for short. It is a product of the renal system used as a buffer to balance CO2 and maintain a normal pH.

Question 4

BE

Answer 4

Base Excess: represents the amount of an acid required to return pH to normal levels
Norm ranges -2 to 2

Question 5

BD

Answer 5

Base Deficit represents the amount of a base required to return pH to normal levels.

Question 6

SaO2

Answer 6

is a measure of the percentage of hemoglobin saturated with oxygen in arterial blood; it is a more accurate depiction of oxygenation than the noninvasive Spo2 provided through pulse oximetry.

Question 7

Kg to tidal volume

Answer 7

6ml/ kg

Question 8

How to get RR from target Ve

Answer 8

Using a target V̇e of 100 mL/kg and an established Vt, a RR of 16 bpm would be required to provide adequate V̇e.

Question 9

If a patient is in volume control ventilation, the respiratory therapist can select either a (wave forms)

Answer 9

constant (square) or decelerating ramp inspiratory flow waveform

Question 10

With flow triggering

Answer 10

a set level of flow must be subtracted from the bias flow in the ventilator circuit before the machine will deliver a breath.

Question 11

With pressure triggering

Answer 11

the pressure in the system must decrease to a set level before the machine will deliver a breath.

Question 12

Flow Volume loop

Answer 12

help identify asynchrony

-also be used to evaluate the degree of airway obstruction and the response to a bronchodilator medication.

Question 13

Inspiratory flow rate

Answer 13

determines how quickly a volume breath will be delivered and has an impact on the ration of inspiration to expiration (I:E ratio).
-Lower inspiratory flow rates result in longer inspiratory times and shorter expiratory times.
-Higher flow rates result in shorter inspiratory times and longer inspiratory times.
=In volume control ventilation, inadequately set flow may show up as a dip in the pressure waveform as the patient attempts to pull more flow than is available.

Question 14

air trapping is the same as

Answer 14

auto peep (expiratory hold)
-can also be detected on the volume, flow, and pressure waveforms.

Question 15

Auto-PEEP can be corrected by

Answer 15

extending the expiratory time, or compensated for by setting PEEP close to auto-PEEP levels to reduce the excessive trigger effort required by the patient

Question 16

One of the main causes of oxygenation defects is

Answer 16

Ventilation/ perfusion (V/Q) mismatch

Question 17

The primary determinants of oxygenation during mechanical ventilation are

Answer 17

FiO2 and Mean airway pressure (Paw)

Question 18

Factors that contribute to Paw during mech. ventilation, including

Answer 18

PIP
PEEP
I:E ratio
Flow

Question 19

The easiest way to manipulate oxygenation across all modes of ventilation is through adjustments in

Answer 19

FiO2 and PEEP

Question 20

With a current Paco2 of 56 mm Hg and a RR of 16 bpm, we are close to the patient’s normal value, but the pH remains acidic. In an attempt to correct it, we can estimate what the Paco2 will be if we increase the RR to 18 bpm.

Answer 20

Current PaCO2 x Set RR = changed RR x X
56 x 16 = 18 x X
896 = 18x
x = 49.7

Question 21

While a Pao2 of 110 mm Hg is great by most standards, remember that the patient is on 100% Fio2. We need to wean Fio2 as soon as possible, but we do not want the patient’s oxygenation to fall below acceptable standards. We can predict how much Fio2 is needed to obtain our minimum standard of a Pao2 of 55 mmHg.

Answer 21

Current PaO2/ Current FiO2 = Desired PaO2/ x
110/ 100% = 55/ x
110 x 55/ 100 = x
x = 60.5 or 60% FiO2

Question 22

Alveolar Ventilation factor of

Answer 22

RR, Vt, Deadspace (Vd/Vt)

Question 23

The amount of air ventilating active alveoli determine the PaCO2

Answer 23

ABG: pH and CO2

Capnography

Question 24

Desired RR

Answer 24

Known PaCO2 x known RR/ Desired PaCO2

Question 25

Desired Vt

Answer 25

Known PaCO2 x known Vt/ Desired PaCO

Question 26

When not to change PaCO

Answer 26

remember pH is primary
If a metabolic acidosis is present then a low PaCO2 may be helpful
Low PaCO2’s are desirable in neurologic problems
Do not under ventilate to compensate for metabolic alkalosis

Question 27

If patient is assisting and hyperventilating

Answer 27

Rulee out hypoxemia, anxiety, pain etc
Change to SIMV to allow smaller assisted breaths
Sedate
Add mechanical deadspace (not recommend)

Question 28

To Increase PaO2 other than increasing FiO2

Answer 28

Increase Mean Airway Pressure (MAP)
PEEP
Increase I time
-Slower flows
-Decelerating ramp
-wave pattern
-Insp. Pause

Question 29

Effects of PEEP

Answer 29

Increases FRC by recruiting alveoli
increases lung compliance
improves gas distribution
improves oxygenation
by reducing shunting

Question 30

Indications

Answer 30

PaO2 < 60 on FiO2 > 60%
A-aDO2 >300 on 100%
PaO2 increases less than 10 with FiO2 change of 20% (refractory hypoxemia)
shunt > 30%
atelectasis
reduced Cl

Question 31

PEEP should be increased/ decreases in incruments of

Answer 31

3-5. allow 5 minutes in between changes

Question 32

Set PEEP at

Answer 32

influction point
as seen as pressure/ volume loop
set above or below this point

Question 33

Check before and after change in PEEP

Answer 33

Heart Rate, Rhythm, SaO2, Blood Pressure