wk 9: mechanical ventilation

mechanical ventilation and what % of room air

process by which FIO2 is moved into ad out of lungs by a mechanical ventilator

• 21% room air or greater

is mechanical ventilation curative?

no, it should just support patients until they recover ability to breathe

artificial airway

placement of a tube into trachea that bypasses airway and laryngeal structures

two types of artificial airways

• endotracheal (ET) intubation

• tracheostomy

why would you need an artificial airway?

if you cannot diffuse gas independently

ex) ARDs, TBI, covid (w/ no alveoli ventilation)

if you can’t breathe properly

when a pt is intubated, what should you always assess?

lung sounds! checks for tube location

• they should be bilaterally sounding (equal expansion on both sides!)

• if one lung is diminished the tube has MOVED

oral ET intubation

procedure of choice — gold standard!

• airway can be secured rapidly

  • decreases WOB

  • easier to remove secretions and perform bronchoscopy

what is the biggest risk for oral ET intubation? also other risks

bleeding!!

quick procedure where teeth can be chipped and cause internal wounds

when preparation for ET intubation, what do you need to ask for and when is it overridden?

• consent (unless emergent)

  • if pt doesn’t have DNR, always ET intubate

• pt teaching

ET intubation equipment needed

• ambu bag on the bedside

• suctioning equipment to prevent choking on secretions

• iv access

before intubation

• preoxygenate with 100% O2

• chin up (sniffing position)

• attempt should be less than 30 secs long

• ventilate w ambu bag between attempts

rapid sequence intubation

for when pt is about to die IN SECONDS

need muscles limp so pt can’t fight, no gag reflex

• a method of ETI

• rapid administration of sedative and paralytic agents

• decreases risk of aspiration and injury to patient

• monitor O2 status!

rapid sequence intubation is not indicated for

cardiac arrest or difficult airway

• pt’s heart will STOP bc CO and HR is ALR LOW

RSI requires sedatives and paralytics

after placing ET tube wyd

• how far above the carina is the tube

• connect tube to mechanical ventilator

• secure airway

• suction et tube and pharynx

• obtain chest x-ray

  • 2-6 cm above carina

after intubation wyd 

• listen to lung

• get chest xray

• obtain ABGs

• monitor SPO2 and end tidal CO2

incorrect tube placement is what and wyd if so

• or accidental extubation

airway emergency! — CALL FOR HELP IMMEDIATELY

could be an accident but compromised breathing regardless

• stay with patient and maintain airway

• support ventilation with ambu bag (BVM)

SPO2 and PaO2 levels

SpO2: greater than or equal to 90%

PaO2: greater than or equal to 60 mmHg

less than 60 is hypoxemia!

clinical sign of hypoxemia

ALOC — change in mental status!

maintaining tube patency, what should you not do?

DO NOT SUCTION THE PATIENT ROUTINELY

• assess for need

when should you suction a ET tube

• visible secretions or suspected aspiration

• sudden onset of respiratory distress

• wet cough

• sudden drop in SpO2 or BP (up or down bp)

• increased peak airway pressure

RN interventions for suctioning (before, during, and after)

before

• always preox 100% O2

during

• suction should be no more than 10 secs

• insert catheter smoothly and gently

• take out catheter slowly and suctioning

• if bp goes up STOP

after

• make sure O2 sats come out

• check if pt is choking or coughing

maintaining tube patency — types of suction (2)

• open suction technique

  • single use only

• closed suction technique

potential complication of suctioning

• hypoxemia, bronchospasm

• increase or decrease in BP

prevention of complications ET (3)

• limit each pass to 10 secs or less

• hyperoxygenate before and after

• monitor ECG and SpO2 before, during, after

managing thick secretions wyd (3)

• adequate hydration — no dairy!

• supplemental humidification

• mobilize and turn patient

negative pressure ventilation

similar to normal ventilation

• non invasive ventilation that does NOT require an artificial airway

positive pressure ventilation (ppv)

• pushes air into lungs under positive pressure during inspiration; intrathoracic pressure increases during lung inflation (opposite of normal)

pushes air in (addition of air = positive)

• what we see at the hospital, main concern

respiration rate for mech vent settings

12-20

tidal volume (Vt) for mech vent settings

keep less than or equal to 500

what happens if Vt is greater than 500?

volutrauma

PEEP for mech vent settings

5-15

what happens if PEEP is greater than 15?

barotrauma

mechanical ventilation settings (5)

• regulate Vt, FiO2, PEEP

  • resp rate, pressure support

• based on pt status 

• adjust till oxygenation and ventilation targets are reached

• based on how much WOB pt can perform

• determined by patient’s ventilatory status, respiratory drive, and ABGs

with mechanical ventilation, always make sure that alarms are what

on and audible

high-pressure limit alarms

triggered when circuit exceeds a preset pressure

ex: coughing, biting, kink

low-pressure limit alarms

pressure in the system is low: leak or disconnection = lowers pressure

• pt can be agitated, confused, pt cough so forcefully it can disconnect

  • create hypoxia in the brain

assist control ventilation (ACV)

provides more control for the patient

• delivers preset Vt at a preset frequency

• when pt initiates a spontaneous breath, preset Vt is delivered (breath than deliver)

• can breathe faster but not slower

synchronized intermittent mandatory ventilation

delivers present Vt in synchrony with patient’s spontaneous breathing

pressure support ventilation (psv)

positive pressure applied only during inspiration and used with spontaneous respirations

• machine senses spontaneous effort and supplies rapid flow of gas initiation of breath

• used for continuous ventilation and weaning

what happens if PEEP is too high (other than barotrauma)

• lungs will be too expanded and the heart will be squished

• increased WOB

• impacted CO, decreased bp, decreased perfusion 

what is PEEP

positive pressure applied to airway during exhalation, preventing alveolar collapse

• keeps alveoli open!

what can often be reduced when PEEP is used?

FiO2

PEEP needs to be used in caution with pts with 

low cardiac output

what should u assess for determining if PEEP is too high

• if pt has subcutaneous emphysema

• asymmetrical chest expansion (always listen to lungs n inspect!)

  • if peep is too high, it would not be going equally to both sides

CPAP and BiPAP

• keeps alveoli open at the end of expiration 

• used to treat obstructive sleep apnea 

• noninvasive!

• causes increased WOB

  • pt needs to breathe against the pressure

wyd if pt tries to take bipap/cpap out? do u put restraints?

no restraints!!!

• if restrained, they can choke if they vomit

needs a sitter

high frequency oscillatory ventilation (HFOV)

not as common

• delivers small tidal volume at rapid resp rate

  • 100-300 breaths per minute

• used for life threatening hypoxia

• short term (30 mins)

  • to recruit back collapsed alveoli

complications of PPV (positive pressure ventilation)

• barotrauma

• volutrauma

• alveolar hypo/erventilation (leak, or too high pressure)

  • watch for COPD pts (at risk)

ventilator associated pneumonia occurs when

48 hrs or more after intubation

ventilator associated pneumonia risk factors

• contaminated respiratory equipment

• inadequate hand washing

• environmental factors

• impaired cough

VAP manifestations (sx)

• fever, high EBC

• purulent sputum — smells

• crackles/wheezes

• pulmonary infiltrates

best position for any kind of respiratory problem

• good lung down! — allows bad lung to expand

• prone position — brings up O2 sat 

VAP bundle (prevention)

• minimizing sedation

• no routine suctioning

• stress ulcer prophylaxis

• elevate HOB 30-45 degrees

• oral care with chlorhexidine

paralyzed pt can…

hear, see, think, feel

complications of ppv (F&E Imbalance)

• progressive fluid retention

• decreased urinary output (30L regular)

• increased sodium retention

complications of ppv (GI effects)

• risk for stress ulcers and GI bleeding

• stress ulcer prophylaxis

wyd if pt family is questioning why you are giving stomach meds for PPV

tell them that PPV puts you at risk for stress ulcers 

nutritional needs increase by how many times the normal calories?

1.5-2x the normal calories

weaning and extubation

• process of reducing ventilator support

• resuming spontaneous breathing

weaning phases

• preweaning

  • assess every day, breath sounds, ABG

• weaning

  • get supplies with med team and extubate (dr only)

• outcome

extubation process

• hyperoxygenate and suction 

• loosen ET tapes or holder

• deflate cuff and remove tube at peak of deep inspiration

• have patient deep breath and cough while tube is pulled out

• supplemental O2 — even if just for a little, check if they can handle being extubated

• careful monitoring after extubation