Comprehensive Overview of Critical Care Procedures: Focus on Pulmonary Management (ABGs & Ventilation)

ventilation definition

movement of air in and out of the lungs

what two systems control ventilation?

musculoskeletal, neuro

respiration definition

O2 & CO2 transport by the alveoli, pulmonary capillaries

which gas do chemoreceptors monitor?

CO2

what three components make up WOB?

compliance, recoil, resistance

what is compliance?

ease of lung opening

what is recoil?

elastic rebound of the lungs to their normal state

what is resistance?

obstacles that block off the flow of air in/out of the lungs

what mismatch is V < Q?

shunt

what is a shunt?

when the alveoli is blocked off, preventing or decreasing gas exchange

what is the mismatch from V > Q?

dead space

what is dead space?

when the alveoli is open, but the blood flow is blocked, keeping gas exchange from happening (so the space is open but there is no movement of gas)

what happens when V x Q?

silent lung, there is no air entering the blocked alveoli and there is little blood flow occurring

what is partial pressure of oxygen (PaO2)?

the amount of oxygen available in the blood to be used for tissue perfusion

normal value for PaO2:

80-100

what is the danger value for PaO2?

<60

what value of PaO2 requires intubation?

>50

what is the normal SaO2 value?

92-99%

what is the pH value for high affinity?

>7.46

what is the pH value for low affinity?

7.26-7.34

what is the pH value for low-low affinity?

<7.25

which affinity is greedy?

high affinity

which affinity is the Good Samaritan?

low affinity

which affinity is the most dangerous?

low-low

what Ls are associated with Left Shift?

aLkalosis, low temp, low CO2

what Rs are associated with Right Shfit?

reduced pH, rising temp, rise in CO2

left shift means l____

lungs

right shift associated with

muscles (remainder)

PaCO2 value

35-45

HCO3 value

22-26

what two things indicate that A/B is uncompensated?

if all three values are matching, or if pH matches with one value and the other is normal

what indicates that A/B is partially compensated?

if one value matches pH and the other is opposite

what indicates that A/B is fully compensated?

if pH is normal and the other two values are opposite of each other

what two A/B values can we change via ventilator?

PaCO2, PaO2

how do we increase PaCO2 (to increase acidity)?

increase RR, increase TV

how do we increase PaO2?

increase FiO2, increase PEEP

how do we decrease PaCO2 (to reduce acidity)?

decrease RR (do not change the TV)

how do we decrease PaO2 (not that we do this often)?

decrease FiO2 (do not change PEEP)

what is a common cause of respiratory acidosis?

COPD

what is a common cause of respiratory alkalosis?

hyperventilation

what is a common cause of metabolic acidosis?

renal failure (high potassium)

what is a common cause of metabolic alkalosis?

bicarb OD, intense vomiting/diarrhea (low potassium)

when is the only time that we treat an acid-base imbalance?

uncompensated

what two things are critical in a patient with an oropharyngeal airway?

not alert, no gag reflex

what is the oxygen L/min cap on a normal nasal cannula?

6 L/min

what is critical to note about a patient on a non-rebreather mask?

if the bag is fully inflated

what two things does a Venturi mask combine?

room air, oxygen

what is an Aquanox an upgraded version of?

a nasal cannula (up to 15 L/min because humidified)

how does a CPAP work?

positive pressure for both inspiration/expiration

what does a CPAP prevent?

atelectasis, alveolar collapse

how does a BiPAP work?

one level for inspiration, one for expiration

what does a BiPAP help with?

WOB, one step before ventilator

what is the requirement for using CPAP/BiPAP?

able to spontaneously breathe and maintain own airway

what are the indications for NIV?

COPD exacerbation, cardiogenic pulmonary edema, Do-Not-Intubate orders in respiratory failure

what are the contraindications for NIV?

respiratory arrest (no breathing), hemodynamic instability, acute MI, uncooperative/agitated, very severe secretions, collapsing airway, recent airway/GI surgery

which type of ventilation can fix acid-base imbalance?

invasive ventilation

what is the most critical thing to avoid in a patient with an ETT/nasotracheal intubation device?

eating/drinking (NPO!!! or aspiration)

which type of invasive ventilation is used in the short-term?

ETT/nasotracheal

what complications are we worried about for ETT/nasotracheal ventilation?

vocal cord dysfunction/rip/edema, bronchospasm, traumatic bleeding or loss of teeth, hypoxia, hypotension and ulcerations

what form of invasive ventilation is used long-term?

tracheostomy (~day 10)

how often do nurses do ventilator trach care?

q12 hrs

what complications are expected with invasive ventilation/

bleeding, infection/ulcers, tube obstruction, fistulas, dysphonia

FiO2 value:

21-60%

Tidal Volume value:

5-8 mL/kg

Respiratory Rate (ventilator) value:

8-20 breaths/min

Inspiratory: Expiratory ratio:

1:2 seconds

does the High Pressure Limit have a number?

no, specific to each patient

Pressure Support value:

5-10 cm/H2O

PEEP value:

3-10 cm/H2O

what is our preferred inspiratory: expiratory ratio in ARDS?

2:1 seconds (because lungs are stiff and wet)

what ventilator modes are used for weaning?

SIMV (synchronized intermittent mandatory volume), CPAP

which ventilator modes are used to prevent trauma in ALI/ARDS?

PC (pressure control), PRVC (pressure regulation volume control)

what does CMV (control mechanical ventilation) do?

everything (all the WOB)

what mode of ventilation is used in patients with weak accessory muscles to gradually strengthen WOB?

AC ('volume' control)

how often are daily extubation screens (sedation vacations) occurring?

daily

when are we trying to extubate?

day 14 at the latest

what are the complications of invasive ventilation?

VAP (ventilator associated pneumonia), VILI (ventilator induced lung injury), cardiac compromise

what's the difference between barotrauma and volutrauma?

barotrauma is damage caused by high pressure, volutrauma is caused by too much volume injected into the lung

how to prevent ventilator complications:

HOB 30-45 degrees, prevent PUD/DVT, oral care q2 hrs, wash hands, early mobilization/ROM

which type of trauma comes from a patient 'fighting' the ventilator?

volutrauma

what ventilator value changes indicate need for suctioning?

elevated PIP, decreased TV