FCCS (Fundamentals of Critical Care Support)
Exam Test Questions And Answers Verified
100% Correct
What is Auto-PEEP?
If the expiratory time is too short to allow full exhalation, the previously delivered breath is not
completely expired and the next lung inflation is superimposed upon the residual gas in the lung.
This results in lung hyperinflation and PEEP above the preset level on the ventilator. This
increase in end-expiratory pressure is called auto-PEEP, or intrinsic, inadvertent, or occult PEEP.
- AKA air trapping
Signs of a patient auto-PEEPing/breathstacking?
The physiologic effects of auto-PEEP on peak, plateau, and mean airway pressures are the same
as those of preset PEEP. (Ex: barotrauma)
- High levels of PEEP may decrease venous return to the heart, resulting in hypotension and
higher PCO2 due to increased dead space, and adversely affect oxygenation (especially with
asymmetric lung disease and COPD) Auto-PEEP may be reduced by the following
interventions:
- Decrease respiratory rate by changing the set rate or sedating the patient. These interventions
result in fewer inspirations per minute and thus increase the total expiratory time available; this
is the most effective way of decreasing auto-PEEP.
- Decrease VT, which requires less time to deliver a smaller breath and allows more time for
exhalation
- Increase gas flow rate, delivering the VT faster and allowing more time in the cycle for
exhalation. This intervention has little impact unless the initial flow rate was set at an
extremely low level. It will also lead to an increase in the airway pressure.
- Change the inspiratory waveform from decelerating (ramp) to constant (square), which delivers
VT in a shorter time, allowing more time for exhalation.
Hypercapnia causes cerebral VASO___?___ and further increases in the intracranial pressure.
vasodilation
As a general rule, FIO2, mean airway pressure, and PEEP affect the ________, whereas the
respiratory rate, dead space (VD), and VT affect alveolar ________________ and _______.
- FIO2, mean airway pressure, and PEEP affect the *PaO2*
- respiratory rate, dead space (VD), and VT affect *alveolar minute ventilation* and *PaCO2*.
Guidelines for the Initiation of Mechanical Ventilation
- Choose the ventilator mode with which you are most familiar. The primary goals of ventilatory
support are adequate oxygenation/ventilation, reduced work of breathing, synchrony between
patient and ventilator, and avoidance of high end-inspiration alveolar pressures.
,- The initial FIO2 should be *1.0.* The FIO2 thereafter can be titrated downward to maintain the
SpO2 at 92% to 94%. In severe acute respiratory distress syndrome, SpO2 ≥88% may be
acceptable to minimize complications of mechanical ventilation.
- Initial VT = *8 to 10 mL/kg* in patients with relatively *normal lung compliance*. In patients
with poor lung compliance (eg, ARDS), a target VT of 6 mL/kg by PBW is recommended to
avoid overdistension and maintain an inspiratory plateau pressure ≤30 cm H2O.
- Choose a respiratory rate and minute ventilation appropriate for the particular clinical
requirements. Target pH, not PaCO2.
- Use PEEP in diffuse lung injury to maintain an open alveoli at end expiration. If volume is held
constant, PEEP may increase peak inspiratory plateau pressure, a potentially undesirable effect
in ARDS. PEEP levels >15 cm H2O are rarely necessary.
- Set the trigger sensitivity to allow minimal patient effort to initiate inspiration. Beware of auto
cycling if the trigger setting is too sensitive.
- In patients at risk of obstructive airway disease, avoid choosing ventilator settings that limit
expiratory time and cause or worsen auto-PEEP.
- Call the critical care consultant or other appropriate consultant for assistance.
What respiratory conditions are likely to respond to Noninvasive Positive Pressure Ventilation?
Hypoxemic Respiratory Failure:
- Cardiogenic pulmonary edema without hemodynamic instability
- Respiratory failure in patients with mild to moderate Pneumocystis pneumonia
- Respiratory failure in immunocompromised patients (especially in hematologic malignancies
and transplant patients)
Hypercapnic Respiratory Failure:
- Acute exacerbation of chronic obstructive pulmonary disease
- Acute exacerbation of asthma
- Respiratory failure in patients with cystic fibrosis Use the following initial ventilator settings
for BiPAP:
Mode: Spontaneous
Trigger: Maximum sensitivity
FIO2: 1.00
EPAP: 4-5 cm H2O (higher levels are poorly tolerated initially)
IPAP: 10-15 cm H2O
Backup rate: Start at 6/min
IPAP > 20 cm H2O may lead to
gastric distension
Contraindications to Use of Noninvasive Positive Pressure Ventilation:
- Cardiac or respiratory arrest
- Hemodynamic instability
- Myocardial ischemia or arrhythmias
- Patient who is unable to cooperate
- Inability to protect the airway
- High risk for aspiration
- Active upper gastrointestinal hemorrhage
- Severe hypoxemia
, - Severe encephalopathy
- Facial trauma, recent surgery, and/or burns
- Significant agitation
Measurements of global oxygen balance that may be useful in monitoring the seriously ill patient
include __________ and _________ central venous oxyhemoglobin saturation (ScvO2) and
lactate concentrations.
How do you measure ScvO2?
ScvO2 can be obtained continuously or intermittently from a catheter placed in the internal
jugular or subclavian vein
ScvO2 correlates with the mixed venous oxyhemoglobin saturation (SVO2) obtained from a
pulmonary artery catheter in the pulmonary artery.
How do you measure SvO2?
PA catheter in pulmonary artery
- this is a mixed venous sample
The SVO2 measures the oxyhemoglobin saturation of blood from the superior vena cava and the
inferior vena cava that has been mixed in the right ventricle. These measures of venous
oxyhemoglobin saturation represent the amount of oxygen still bound to hemoglobin after
traversing the tissue capillaries and returning to the right heart; the decrease from the SaO2
estimates the amount of oxygen utilized
In normal individuals, the SVO2 is _____% and the ScvO2 is 2% to 3% lower.
However, in patients with shock and/or hypoperfusion, the ScvO2 may be 5% to 7% higher than
the SVO2 due to greater desaturation of venous blood from the gastrointestinal tract contributing
to SVO2
>65%
Low values of ScvO2 suggest an imbalance in the oxygen supply and demand. This imbalance
may be due to decreases in:
-
-
-
Patients may have more than one abnormality contributing to oxygen imbalance. -
cardiac output
- hemoglobin concentration, or SaO2,
- increases in tissue oxygen consumption.(fever/sepsis)
A normal ScvO2 may still be associated with tissue hypoxia in conditions such as severe sepsis
and certain poisonings (eg, _______). Further evaluations of lactate concentration and organ
function are needed to assess oxygen balance in the seriously ill patient when the ScvO2 is
normal. cyanide
Lactate is another indicator of the overall oxygen balance. It is produced during anaerobic
metabolism when cellular ___________ occurs. The elevation of blood lactate in shock and
hypoperfusion may be due to inadequate oxygen supply to tissue but also may be affected
by altered hepatic metabolism, use of vasoactive drugs, and other factors. hypoxia
occurs
Exam Test Questions And Answers Verified
100% Correct
What is Auto-PEEP?
If the expiratory time is too short to allow full exhalation, the previously delivered breath is not
completely expired and the next lung inflation is superimposed upon the residual gas in the lung.
This results in lung hyperinflation and PEEP above the preset level on the ventilator. This
increase in end-expiratory pressure is called auto-PEEP, or intrinsic, inadvertent, or occult PEEP.
- AKA air trapping
Signs of a patient auto-PEEPing/breathstacking?
The physiologic effects of auto-PEEP on peak, plateau, and mean airway pressures are the same
as those of preset PEEP. (Ex: barotrauma)
- High levels of PEEP may decrease venous return to the heart, resulting in hypotension and
higher PCO2 due to increased dead space, and adversely affect oxygenation (especially with
asymmetric lung disease and COPD) Auto-PEEP may be reduced by the following
interventions:
- Decrease respiratory rate by changing the set rate or sedating the patient. These interventions
result in fewer inspirations per minute and thus increase the total expiratory time available; this
is the most effective way of decreasing auto-PEEP.
- Decrease VT, which requires less time to deliver a smaller breath and allows more time for
exhalation
- Increase gas flow rate, delivering the VT faster and allowing more time in the cycle for
exhalation. This intervention has little impact unless the initial flow rate was set at an
extremely low level. It will also lead to an increase in the airway pressure.
- Change the inspiratory waveform from decelerating (ramp) to constant (square), which delivers
VT in a shorter time, allowing more time for exhalation.
Hypercapnia causes cerebral VASO___?___ and further increases in the intracranial pressure.
vasodilation
As a general rule, FIO2, mean airway pressure, and PEEP affect the ________, whereas the
respiratory rate, dead space (VD), and VT affect alveolar ________________ and _______.
- FIO2, mean airway pressure, and PEEP affect the *PaO2*
- respiratory rate, dead space (VD), and VT affect *alveolar minute ventilation* and *PaCO2*.
Guidelines for the Initiation of Mechanical Ventilation
- Choose the ventilator mode with which you are most familiar. The primary goals of ventilatory
support are adequate oxygenation/ventilation, reduced work of breathing, synchrony between
patient and ventilator, and avoidance of high end-inspiration alveolar pressures.
,- The initial FIO2 should be *1.0.* The FIO2 thereafter can be titrated downward to maintain the
SpO2 at 92% to 94%. In severe acute respiratory distress syndrome, SpO2 ≥88% may be
acceptable to minimize complications of mechanical ventilation.
- Initial VT = *8 to 10 mL/kg* in patients with relatively *normal lung compliance*. In patients
with poor lung compliance (eg, ARDS), a target VT of 6 mL/kg by PBW is recommended to
avoid overdistension and maintain an inspiratory plateau pressure ≤30 cm H2O.
- Choose a respiratory rate and minute ventilation appropriate for the particular clinical
requirements. Target pH, not PaCO2.
- Use PEEP in diffuse lung injury to maintain an open alveoli at end expiration. If volume is held
constant, PEEP may increase peak inspiratory plateau pressure, a potentially undesirable effect
in ARDS. PEEP levels >15 cm H2O are rarely necessary.
- Set the trigger sensitivity to allow minimal patient effort to initiate inspiration. Beware of auto
cycling if the trigger setting is too sensitive.
- In patients at risk of obstructive airway disease, avoid choosing ventilator settings that limit
expiratory time and cause or worsen auto-PEEP.
- Call the critical care consultant or other appropriate consultant for assistance.
What respiratory conditions are likely to respond to Noninvasive Positive Pressure Ventilation?
Hypoxemic Respiratory Failure:
- Cardiogenic pulmonary edema without hemodynamic instability
- Respiratory failure in patients with mild to moderate Pneumocystis pneumonia
- Respiratory failure in immunocompromised patients (especially in hematologic malignancies
and transplant patients)
Hypercapnic Respiratory Failure:
- Acute exacerbation of chronic obstructive pulmonary disease
- Acute exacerbation of asthma
- Respiratory failure in patients with cystic fibrosis Use the following initial ventilator settings
for BiPAP:
Mode: Spontaneous
Trigger: Maximum sensitivity
FIO2: 1.00
EPAP: 4-5 cm H2O (higher levels are poorly tolerated initially)
IPAP: 10-15 cm H2O
Backup rate: Start at 6/min
IPAP > 20 cm H2O may lead to
gastric distension
Contraindications to Use of Noninvasive Positive Pressure Ventilation:
- Cardiac or respiratory arrest
- Hemodynamic instability
- Myocardial ischemia or arrhythmias
- Patient who is unable to cooperate
- Inability to protect the airway
- High risk for aspiration
- Active upper gastrointestinal hemorrhage
- Severe hypoxemia
, - Severe encephalopathy
- Facial trauma, recent surgery, and/or burns
- Significant agitation
Measurements of global oxygen balance that may be useful in monitoring the seriously ill patient
include __________ and _________ central venous oxyhemoglobin saturation (ScvO2) and
lactate concentrations.
How do you measure ScvO2?
ScvO2 can be obtained continuously or intermittently from a catheter placed in the internal
jugular or subclavian vein
ScvO2 correlates with the mixed venous oxyhemoglobin saturation (SVO2) obtained from a
pulmonary artery catheter in the pulmonary artery.
How do you measure SvO2?
PA catheter in pulmonary artery
- this is a mixed venous sample
The SVO2 measures the oxyhemoglobin saturation of blood from the superior vena cava and the
inferior vena cava that has been mixed in the right ventricle. These measures of venous
oxyhemoglobin saturation represent the amount of oxygen still bound to hemoglobin after
traversing the tissue capillaries and returning to the right heart; the decrease from the SaO2
estimates the amount of oxygen utilized
In normal individuals, the SVO2 is _____% and the ScvO2 is 2% to 3% lower.
However, in patients with shock and/or hypoperfusion, the ScvO2 may be 5% to 7% higher than
the SVO2 due to greater desaturation of venous blood from the gastrointestinal tract contributing
to SVO2
>65%
Low values of ScvO2 suggest an imbalance in the oxygen supply and demand. This imbalance
may be due to decreases in:
-
-
-
Patients may have more than one abnormality contributing to oxygen imbalance. -
cardiac output
- hemoglobin concentration, or SaO2,
- increases in tissue oxygen consumption.(fever/sepsis)
A normal ScvO2 may still be associated with tissue hypoxia in conditions such as severe sepsis
and certain poisonings (eg, _______). Further evaluations of lactate concentration and organ
function are needed to assess oxygen balance in the seriously ill patient when the ScvO2 is
normal. cyanide
Lactate is another indicator of the overall oxygen balance. It is produced during anaerobic
metabolism when cellular ___________ occurs. The elevation of blood lactate in shock and
hypoperfusion may be due to inadequate oxygen supply to tissue but also may be affected
by altered hepatic metabolism, use of vasoactive drugs, and other factors. hypoxia
occurs
