RESP 2240 Adults II

What is the difference between ventilator liberation versus discontinuing ventilatory support?

Ventilator liberation is the physical removal of a patient from the ventilator, such as in T-Piece trials

Discontinuing ventilatory support is the removal of all aspects of ventilation - ETT, trach, ventilator, etc

How many patients require a systemic approach to ventilator weaning?

15-20%

What patients have a high likelihood of rapid weaning?

• presenting problem resolves in 72h

• adequate weaning parameters

• good PSV/CPAP results in a 30-90min trial

What patients may be successfully removed from a ventilator but should be trached?

no vent needs:

• patient comfort

• decrease Raw

vent needs:

• extreme secretions

• protect airway

• enhance mobility

• allow patient to eat and speak

If a patient repeatedly fails their SBT, what should be considered?

systemic weaning strategy

What is the difference between protocol and physician directed weaning?

Protocol: care team uses detailed, direct weaning protocol to initiate weaning as patient meets criteria - IDEAL

Physician Directed: physician determines pace of weaning based on reports during rounds and personal opinion

What is the most common method of weaning?

SBT alternating with rest periods in A/C, SIMV, or on high PSV

Why might a patient fail ventilator discontinuation?

• distress post-extubation leads to significant hypercapnia

• myocardial ischemia

• ventilatory demand higher than ventilatory capacity

What are complications of prolonged intubation and ventilation in the ICU?

• higher risk of nosocomial infection

• VAP risk

What is ventilator dependence?

the need for ventilatory support for more than 2 weeks or the failure of multiple weaning attempts

What are the characteristics of ventilatory workload and demand?

the effort required by respiratory muscles to maintain adequate ventilation

influenced by:

• total required ventilation level - CNS drive, dead space, metabolic rate

• lung + thorax compliance

• Raw

• intrinsic WOB - artificual airways, partial airway obstruction, autoPEEP

What are the characteristics of ventilatory capacity?

influenced by CNS drive, muscle strength, and muscle endurance

factors such as malnutrition, starvation, and electrolyte imbalances may impair ventilatory muscle function

What clinical factors should be evaluated when considering weaning?

• acid-base balance

• anemia/abnormal hemoglobin

• cardiac arrhythmias

• fluid balance

• pain

• hemodynamic stability

• sleep deprivation

What key metabolic factors should be considered prior to weaning?

excess carb feeding may increase CO2 production - precipitates acute hypercapnic resp failure

What key renal factors should be considered prior to weaning?

• adequate urine output

• no weight gain

What key cardiovascular factors should be considered prior to weaning?

• arrhythmias

• hypotension

• severe hypertension

What key neurologic factors should be considered prior to weaning?

• awake, alert, and able to follow instructions

• sedation, NMBA, and narcotics minimized

• minimal anxiety, pain, and stress

How does metabolic acidosis impact weaning?

low bicarb causes increased RR - increased drive makes weaning difficult

How does metabolic alkalosis impact weaning?

mechanical hyperventilation may reduce ventilatory drive

What oxygenation criteria is best to support a successful weaning?

• PaO2 > 60 (>55 in chronic lungs)

• FiO2 < 40-50 with PEEP 5-8

• PF ratio > 150-200

• SpO2 > 94 (unless chronic)

What ventilation criteria is best to support a successful weaning?

PaCO2 35-45 with RSBI < 105

How should a patient be prepared prior to PSV/SBT trial?

• fully rested and stable - no physio, CRRT, transport prior

• maximal bronchodilator and anti-inflammatory meds

• bronchial hygiene

• communicate clearly with patient to reduce anxiety

• optimal nutrition, ABG, fluid balance, etc

What are the characteristics of Spontaneous Awakening Trials (SAT)?

extended sedation use is cause for concern in critically ill patients - spontaneous awakening of patients along with daily SBT will improve weaning and decrease mortality

What factors should be measured to assess weaning?

• RSBI

• PF ration

• A-a gradient

• MIP, MVV, VC

• P0.1

• WOB

How is a patient’s RSBI measured during weaning?

• on minimal PSV or SBT/CPAP trial

• assess first RSBI after 1-2min (+ patient status) for immediate resp distress

• reassess at 5min, 30min, 1h, and 90min

What are the potential values of RSBI and what do they indicate?

>105 breaths/L/min: likely to fail

<105: likely to be successful

<60: strong predictor of success

When is RSBI not reliable for weaning parameters?

• neonates

• pediatrics

• adults with high baseline RR

• adults with very small PBW (<45)

How does P0.1 help to assess weaning?

• airway is occluded by ventilator for the first 100ms of inspiration and UA pressure is measured

• reflects drive to breath and ventilatory muscle strength

  • increases proportionally to an increase in pCO2

• breath-by-breath variability - average 3-5 values

• normally 0 to -2

• >- 6: high risk of weaning failur

What should weaning index values be prior to attempting SBT?

WOB: <0.8 J/L or <1.6 kg m/min

VD/VT: <0.55-0.6

Oxygen cost of breathing: <15% VO2

P0.1: <6

CROP index: <13 ml/breath/min

What are signs of weaning failure?

• tachycardia, HTN

• paradoxical breathing

• respiratory alterans

• accessory muscle use

• fatigue

What are the characteristics of SIMV weaning?

• easy to use

• evidence shows its not very effective

• support is set below the patients required level, patient must make up the difference

• mandatory RR is decreased 1-2 breaths at a time

• may add PSV of 5-10 to overcome ETT resistance and reduce WOB

What are possible complications of SIMV?

• prolonged weaning may increase resp fatigue

• may lead to vent asynchrony

  • breath stacking

  • triggering issues

  • autoPEEP

What are the characteristics of T-Piece weaning?

• oldest method of weaning, may be used in those difficult to wean

• use of LVN to give humidity and oxygen

• 5-10 min SBT, 1-4h resting on A/C or PSV

  • gradually increase SBT times and decrease rest

What are the characteristics of PAV weaning?

seems to successfully wean patietns better than PSV, and may shorten total MV time and ICU stay

What are the characteristics of NAVA weaning?

good evidence with weaning and has positive impact on overall patient survival

What are the characteristics of ASV weaning?

may be beneficial in patients with COPD

What should the wait period be after a failed SBT be? Why?

24 hours, to allow for recovery of resp muscles and to optimize patient condition

When should multiple SBTs in one day be considered or not?

can improve resp muscle endurance, may consider if difficult-to-wean patients

risk of increasing fatigue and failure rates

What are possible causes of SBT failure?

respiratory: weak muscles, poor secretion clearance, airway resistance

CV: heart failure, fluid overload, hemodynamic instability

neurological: decreased drive, excessive sedation, delirium

metabolic: electrolyte imbalance, malnutrition

What should the pressure support be set to during an SBT in patients on MV for more than 24 hours?

5-8

What key factors determine extubation readiness in a patient?

• airway patency: able to maintain open airway, low risk of post-extubation stridor, adequate secretion removal

• airway protection: cough strength, swallow/gag reflex

• clinical protocol: follow extubation guidelines

What are possible complications following extubation?

• hoarse/sore throat

• cough

• subglottic edema

• high WOB

• airway obstruction

• larygnospasm

• aspiration

• stridor

How may post-extubation stridor be managed?

epinephrine, steroids, heliox

How can risk of post-extubation stridor be assessed?

cough and gag reflex

cuff leak test

• disconnect patient from ventilator, defleate cuff, block the tube, and allow for spont breathing

• leak <110mL = high risk

What are the two types of “unplanned extubations” (UE)?

self-extubation: patient removes tube, MAY REFLECT READINESS

accidental extubation: tube becomes dislodged during care

What are the characteristics of prolonged-ventilation tracheostomy?

considered 10-14 days after intubation IF: multiple wean attempts are unsuccessful or theres a large change in prognosis

may be easier to wean as its more comfortable and decreases dead space and reistance

What patients may benefit from tracheostomy weaning?

• require increased mobility

• need to decrease Raw and dead space, improves secretion clearance

• high sedation requirements

• psychological benefits

What is the difference between terminal weaning and terminal extubation?

weaning

• ETT remains in place

• vent support is gradually withdrawl

• often preferred, helps maintain airway patency

extubation

• ETT is removed

• ventilatory support is withdrawn alongside

• patient breathes spontaneously until death

How is apnea testing preformed?

• ABG drawn as a pretest, patient is preoxygenated and disconnected from ventilator

  • still giving O2 via suction catheter attached to flowmeter(6L/min)

• assess for breathing efforts

• ABG drawn every several minutes

• no respiratory effort with PaCO2 >60 or increased >20 from baseline = braindeath

What are the steps to terminal extubation?

1. Decision/Documentation

• document goals of care and discuss with team

• encourage cultural rituals/ceremonies

• discontinue tests, meds, etc that do not meet goals of care

• confirm DNR + extubation order in chart

2. Prep for removal of MV

• discontinue artificial fluids/feedig

• provide family counselling

• discuss organ donation

• determine form of removal from MV

• pre-medicate for comfort

• remove restraints/medical devices

3. Removal of MV

• silence alarms, turn off vent and vitals monitors

• remove ventilator

• assess patient for signs of discomfort

4. Follow up

• invite family to room, allow time to say goodbye

• debrief staff

• initiate bereavement plant

What is long-term ventilation?

the treatment of chronic respiratory failure with external devices such as ventilators.

patients require >6h/day of ventilatory support for >21 days

What are common indications for long-term MV?

• ALS

• central hhypoventilation syndrome (CHS)

• OHS

• SCI

• Duchenne MD

• myotonic dystrophy

• post-polio syndrome

What should be monitored in long-term ventilated patients?

• PFTs

• Muscle strength - MIP, MEP

• peak cough flow

• CO2 and HCO3

• echo

• CXR

• diaphragm ultrasound

What BiPAP modes are common in LTV?

• S (spont) and S/T (spont/timed)

• PC

• IVAPS (vol-assured p support)

What are the characteristics of Sip ‘n Puff (MPV) ventilation?

• daytime use

• “puffs” of air with set Vt or P

• minimal to no alarms

• battery powered

• patient placed on BiPAP overnight

What is set in MPV for LTV?

• vol or P mode

• vol - allows for breath stacjing

• RR

• trigger

• insp time

What are the advantages of diaphragm pacing over LTV?

• better distribution to dependent lung

• improved speech

• preserves sense of smell

• mobility, reduced cost of care

Patients requiring invasive LTV demonstrate what?

• an inability to be completely weaned from invasive ventilation

• a progression of disease etiology requiring increasing ventilatory support

Why are the rates of LTMV increasing?

• neonatal survival rates

• decreased mortality in critically ill populations

• increased NIV use

What are the therapeutic objectives of LTMV?

• normalizing CO2 and WOB

• improving QL

• improved physical/psychological level of function

• reducing mortality and hospitalizations

• prolonging life

What are common vent settings in LTMV?

• vol A/C

  • P in peds

• Ve 6-8 or 8-10

What are the risks of inadequate humidification in LTV?

• imparied ciliary activity

• impaired mucus removal

• nasal resistance

• discomfort

• low compliance in NIV

What are the characteristics of the Trilogy ventilator?

• LTV for N/IV

• dual-mode prescription

• peds or adult

• passive and active circuit options

• mouthpiece ventilation

• shows waveforms

• lightweight with carry bag and external battery

What are the characteristics of the Astral 150 ventilator?

• LTV

• 4 programs

• peds and adults

• leak and active circuit options

• mouthpiece ventilation

• waveform display

• remote monitoring option

• lightweight with carry bag and external battery

What are the advantages of glottic closure with a one-way valve?

• facilitates full voice and the ability to speak in full scentences - improves communication

• ability to breath stack and prevent atelectasis

• facilitates coughing

• can use uncuffed trach tube

• improves swallowing

What indicates a patients ability to transition to community LTV?

• medically stable without constant/frequent monitoring, tests, or treatment changes

• patient and family are motivated to move to community

• adequate home setting

• sufficient caregiver support

• access to adequate resources

• access to proper equipment, which has been selected and ordered

• known source for ongoing supply restocks

What are the key elements of a successful transition to community LTV?

• proper timing

• starting early in ICU

• adapt, simplify, demystify

How can successful community transition to LTV be supported in the ICU?

• adapt: care to patient needs: wean asap, shift to independence model, set parameters to patient comfort

• simplify: wean off support (ie. monitors) early, switch to LTC vent once baseline is established

• demystify: involve patient and family in care, introduce adjunct therapy, familiarize with equipment and care

What should patients and caregivers be educated on prior to community transition?

• ventilator operation

• CPR

• bronchopulmonary hygiene

• LVR

• airway care and equipment cleaning

• med delivery

• nursing care - wounds, bathing, feeding

• emergency preparedness

What difference should be maintained between IPAP and EPAP?

>/= 4cmH2O

What happens when IPAP is changed?

alters ventilation/CO2 removal

What happens when EPAP is changed?

impacts oxygenation and recruitment

What patients tend to do the best on NIPPV?

• high LOC

• young age

• less severe state

• synchronous breathing efforts

• low quantity of secretions, no pneumonia

What patients are contraindicated with NIPPV use?

• ARDS

• apnea

• high aspiration risk/cant protect airway

• hemodynamic/cardiac instability

• uncooperative

• facial burns/trauma/abnormal anatomy

• excessive secretions

What patients have the strongest response to NIPPV?

COPD exacerbation, CHF, and cardiogenic pulm edema

In what patient populations is NIPPV use limited/controversial?

Asthma, pneumonia (only use with COPD), post-op resp failure

How may NIPPV be used in immunosuppressed patients?

hypoxemic respiratory failure development, especially when awaiting a lung transplant, was significantly improved with NIC

How should a patient be positioned prior to NIV initiation?

laying down, head of bed >/= 30 degrees

How should BiPAP be initiated in acute care?

textbook: IPAP 8, EPAP 4-5

clinically: IPAP 14-18, EPAP 6-10

How should NIV be initiated?

• position patient and turn on + connect device

• set initial settings, hold the mask to the patients face until they are comfortable with the sensation

• adjust FiO2 and pressure as needed

• once comfortable, increase IPAP until Vt is 4-6 and increase PEEP to improve oxygenation/reduce autoPEEP

• check for leaks

• assess every 30min for first 1-2h

What indicates a successful NIV initiation?

• PaCO2 decreases

• pH increases

• PaO2 increases

• decreased RR

• diminished accessory muscle use

What indicates a failure of NIV initiation?

• not improving or worsening ABG

• RR>30

• SpO2<90%

• decreased LOC

• inability to clear secretions

• cant tolerate

• hemodynamic instability

What changes should be made on NIV if patient has a high PaCO2?

increase pressure (Vt) or rate

What changes should be made on NIV if patient has a low PaCO2?

decrease pressure (Vt) or rate if oversupporting

What changes should be made on NIV if patient has a high PaO2?

decrease oxygen or PEEP

What changes should be made on NIV if patient has a low PaO2?

increase oxygen or PEEP (may alter Vt)

What should be monitored in patients on NIV?

• leaks

• ventilator synchrony, patient comfort

• accessory muscle use, vitals, ABGs

What are possible major complications of NIV?

aspiration, hypotension, pneumothorax

What are common causes of NIV noncompliance?

mask discomfort, claustrophobia, anxiety, confusion, etc

What are common limitations of NIV?

• UNCOMFORTABLE

• leaks common

• nasal/oral dryness

• gastric inflation

• skin irritation, ulcers, bleeding

• claustrophobia

How is NIPPV typically weaned in acute patients?

• reduce pressure support and PEEP

• increase trial times off of NIPPV

• normally, just discontinue and monitor

What can be set on HFT?

flow, FiO2, and humidity

What are typical initial HFT settings (in adults)?

• flow 50 (35-60)

• FiO2 meets SpO2 goals >94%

What are the benefits of HFT?

• warm humidity improves mucus motility and prevents plugging

• more comfortable

• allows NIPPV-dependent patients to eat/recieve care without significant desaturations

How is HFT typically weaned/escalated?

weaning: once they reach 40L and 40% FiO2, switch to a conventional form of O2

ROX index (SpO2/FiO2)/(RR) can predict need for intubation/higher support

What are the indications for LVR/MI-E?

neuromuscular weakness, ineffective cough, low peak cough flows, low lung vol

What is Mechanical Insufflation/Exsufflation?

device programmed for inflation of the lungs to a set pressure, followed by an immediate switch to negative pressure, increasing expiratory flow

simulates a cough, aids in secretion mobility through larger airways

What is manual assisted cough?

manual diaphragm compression, helps eternal respiratory/abdominal muscles to produce an effective cough

for patients with neuromuscular weakness or SCI patients

What is postural drainage?

use of gravity to drain patients lung segments into central airways, where it can be removed by cough or suction

How does N-Acetylcystine work in the body?

ie. Mucomyst

breaks up mucus, thinning it and making it easier to expectorate