Exam Review Respiratory 420 Exam 1

Comprehensive question-and-answer flashcards based on respiratory exam review covering ventilator modes, parameters, formulas, alarms, and clinical indicators.

What parameters are assessed in the Glasgow Coma Scale?

Best motor response, best verbal response, and best eye movement response.

At what Glasgow Coma Scale score is intubation indicated?

A score equal to or less than 8 ($\le 8$).

What are common causes for a ventilator high pressure alarm?

Secretions or a kinked tube.

What are common causes for a ventilator low pressure alarm?

A leak in the cuff, tube, or ventilator circuit.

What change in lung mechanics is indicated if PIP is rising while $P_{plat}$ remains constant?

An increase in airway resistance.

What change in lung mechanics is indicated if both PIP and $P_{plat}$ increase or decrease together?

A change in lung compliance.

What does a normal compliance with a widening difference between PIP and $P_{plat}$ signify?

Increasing airway resistance.

Which disease condition is characterized by high compliance?

Emphysema.

In Pressure Control ventilation, which parameters are set and which parameter varies?

PIP and I-time (normal initial is $0.7 - 1.1\,\text{sec}$) are set, while volume varies.

How should ventilator parameters be modified for a high $PaCO_2$ in either pressure or volume control mode?

Increase PIP (or volume) and increase rate.

How should ventilator parameters be adjusted to address a low $PaO_2$?

Increase $FiO_2$ until reaching $60\%$, then increase PEEP.

In Volume Control ventilation, which parameters are set and which parameter varies?

Tidal volume ($VT$), rate, and peak flow or I-time are set, while PIP varies.

What effect does increasing peak flow have on timing in Volume Control mode?

It increases I-time and lengthens E-time.

How is high $PaCO_2$ corrected in Volume Control mode?

Increase tidal volume ($VT$) or rate (calculating IBW if given height).

What are clinical reasons to switch a patient from Assist-Control (AC) to SIMV?

Breath stacking, breathing too much, or low $PaCO_2$.

What are clinical reasons to switch a patient from SIMV to Assist-Control (AC)?

Patient not triggering their own breath or high $PaCO_2$.

What step is required when determining initial mechanical ventilator settings?

Find the patient's Ideal Body Weight (IBW).

How can Assist-Control (AC) and SIMV modes be identified on ventilator scalars?

In AC every breath is a full ventilator breath, whereas in SIMV there are ventilator breaths along with smaller spontaneous breaths.

What clinical presentations indicate a need for intubation?

Drug overdose (OD), cyanosis, gasping for air, inability to protect the airway, or asthma so severe the patient cannot say more than one word at a time.

How is Rise Time defined in Pressure Control ventilation?

How long it takes to reach the Peak Inspiratory Pressure (PIP).

How is I-time defined in mechanical ventilation?

How long the patient spends in the inspiratory phase.

What is auto-PEEP and on which scalar is it identified?

Auto-PEEP is identified on the flow scalar when a patient starts the next breath before exhaling to baseline.

Which maneuver is performed to measure auto-PEEP?

Expiratory hold maneuver.

What adjustments can fix auto-PEEP on a ventilator?

Decrease I-time, increase E-time, or increase peak flow.

Which ventilator maneuver is used to obtain plateau pressure ($P_{plat}$)?

Inspiratory hold.

What conditions and monitoring requirements are needed during apnea testing?

Normal body temperature and ABG sampling every $5\,\text{mins}$.

Which diagnostic test is used to confirm brain death?

Computed Tomography Angiography (CTA).

At what levels do internal and external expiration occur?

Internal expiration is at the tissue level; external expiration is at the organ level.

What does bird beaking on a ventilator loop represent and how is it fixed?

It represents over-distention of alveoli and is fixed by lowering tidal volume ($VT$).

What roles do Trigger, Limit, and Cycle play in a ventilator breath?

Trigger initiates the breath, Limit stops/restricts inspiration parameters, and Cycle causes the breath to be over.

What action should be taken if a Heat and Moisture Exchanger (HME) is getting clogged?

Add humidification.

What features are observed on a chest X-ray (CXR) with a pneumothorax?

Air present, trachea deviated away from the pneumothorax, and no vascular markings.

Where is needle decompression puncture performed?

At the $2\text{nd} - 3\text{rd}$ intercostal midclavicular line.

What chest X-ray finding indicates a pleural effusion?

Blunted costophrenic angles.

What is the formula for Total Cycle Time ($TCT$)?

$$TCT = \frac{60\,\text{sec}}{RR}$$

How do you calculate I-time or E-time when $TCT$ is known?

$$TCT - \text{what is given}$$

What is the formula for Minute Ventilation ($MV$)?

$MV = TV \times RR$ (liters per minute)

What is the formula for Alveolar Minute Ventilation ($ALV\,mv$)?

$$ALV\,mv = (TV - IBW\,(\text{lbs})) \times RR$$

What is the formula to calculate a desired $TV$ or $RR$ for a desired $CO_2$?

$$\frac{\text{Known } (TV \text{ or } RR) \times \text{known } CO_2}{\text{desired } CO_2}$$

What does Peak Inspiratory Pressure ($PIP$) represent?

The highest pressure given during that breath, taking into consideration both compliance and resistance.

What component of lung mechanics does Plateau Pressure ($P_{plat}$) reflect?

Compliance only.

What is the formula for Dynamic Compliance?

$$\text{Dynamic Compliance} = \frac{VT}{PIP - PEEP}$$

What is the formula for Static Compliance?

$$\text{Static Compliance} = \frac{VT}{P_{plat} - PEEP}$$

What is the formula for Airway Resistance ($R_{aw}$)?

$$R_{aw} = \frac{PIP - P_{plat}}{\text{flow}} \times 60$$

What is the formula for Rapid Shallow Breathing Index ($RSBI$) and its threshold value?

$RSBI = \frac{RR}{VT\,(\text{decimal})}$ with a threshold value of $RSBI < 105$.

What is the formula for Arterial Oxygen Content ($CaO_2$) and how is oxygen distributed in blood?

$CaO_2 = (PaO_2 \times 0.003) + (Hb \times 1.34 \times SaO_2\,(\text{decimal}))$ with $98\%$ bound to hemoglobin and $2\%$ free flowing in plasma.

What is the formula for Alveolar Oxygen Tension ($PAO_2$)?

$$PAO_2 = FiO_2\,(\text{decimal}) \times (P_b - H_2O\,(47)) - \frac{PaCO_2}{0.8}$$

What is the formula for the Alveolar-arterial Oxygen Gradient ($P(A-a)O_2$)?

$$P(A-a)O_2 = PAO_2 - PaO_2$$

What is the formula for Deadspace Fraction ($V_d/V_t$) and what are its normal and critical values?

$V_d/V_t = \frac{PaCO_2 - PeCO_2}{PaCO_2}$ where Normal is $20\% - 40\%$ and Critical is $> 60\%$.

How is physiological deadspace defined?

Ventilation with no perfusion.

What disease condition is classified as a deadspace disease?

Pulmonary embolism.

What are the formulas for Tubing Compressibility ($TC$) and actual delivered volume?

$TC = (PIP - PEEP) \times TCF$ and delivered volume is $VT - TCF$.