Transcript RSP 233 - macomb

RSPT 2335
Mechanical Ventilation
Module E
Discontinuation
MODULE E
Assignments

READ:
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Pilbeam’s Mechanical Ventilation
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Chapter 20 & 21 (pp. 402 – 427 & 428 – 452)
Egan References:
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Chapter 47 (pp. 1199 - 1227)
MODULE E
Assignments

Review:
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ACCP, AARC, ACCCM - Evidence Based
Clinical Practice Guideline: Weaning and
Discontinuing Ventilatory Support
Homework:
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Locate a copy of an actual ventilator
weaning protocol at your work or clinical
site.
Optional Videotapes &
DVDs
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AARC PR 2005: Weaning Prolonged Mechanical
Ventilation Patients in LTACHs (DVD)
AARC PR 2004: Withholding and Withdrawing Life
Support in the ICU
AARC PR 2003: Weaning the Long Term
Ventilator Dependent Patient
AARC PR 2002: Transitioning the Ventilator
Patient From the Hospital to Home
AARC PR 2002: Talking With Patient’s and
Families About Death and Dying
Passy-Muir Tracheostomy & Ventilation Speaking
Valves
MODULE E
Objectives
When you complete this module, you
should be able to…
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List the different ways to wean from
mechanical ventilation and explain
which are the most commonly used
methods.
Explain the 12 guidelines as stated in
the ACCP, AARC, ACCCM - Evidence
Based Guidelines.
Describe how to assess discontinuation
potential.
MODULE E
Objectives
When you complete this module, you
should be able to…
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Describe how to do a spontaneous
breathing trial.
Describe the signs of a patient in
distress.
Explain how to evaluate the objective
and subjective signs of tolerance of a
spontaneous breathing trial.
Objectives
(continued)
When you complete this module, you
should be able to…
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Explain the process to follow if a patient
fails a SBT.
Describe the assessment
recommended prior to extubation.
Explain the present viewpoint on the
use of weaning parameters.
Objectives
(continued)
When you complete this module, you
should be able to…
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Explain the purpose of weaning
protocols and how they work.
Explain when tracheotomy should be
considered.
List the criteria for permanent ventilator
dependence.
Objectives
(continued)
When you complete this module, you
should be able to…
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Describe how to use a Passy Muir
valve on a ventilator dependent patient.
Explain the criteria for terminal
weaning.
List the different types of Advanced
Directives.
Objectives
(continued)
When you complete this module, you
should be able to…
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Explain the hierarchy for health care
decision making and the role of the
Durable Power of Attorney for health
care.
Explain the “Criteria for Determination of
Brain Death.
Describe the apnea testing procedure
and why it is done.
MODULE E
Major Topics
1. Liberation from Ventilation &
Weaning Parameters
2. Evidence-Based Guidelines for
Weaning and Discontinuing
Ventilatory Support
3. End of Life Issues
Part 1
Liberation & Parameters
Balance Between Conservative
and Aggressive Weaning
Complications of
Premature Extubation
Complications of
Prolonged Ventilation
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Infection
Lung Injury
Laryngeal Injury
Cost
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Prolonged ICU Stay
Upper Airway Injury
Infection
Mortality
A Reasonable Re-Intubation Rate is
10 – 20%.
There are many methods for
withdrawing the mechanical
ventilator

Titrated
Bi-Level
 Bi-Level + PS
 Pressure
Support
 SIMV
 SIMV + PS
 T-piece
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Automated
ATC
 VS
 PAV
 VAPS or PAug
 Automode
 MMV
 ASV
 Smart Care
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Method to Use
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Use method supported by
evidence.
Monitor & assess patient
frequently.
Start weaning as soon as possible.
Have a protocol with clear
parameters & procedures.
“Weaning” Parameters
• Mechanics
• Spontaneous tidal volume and
respiratory rate.
• Rapid Shallow Breathing Index
• Vital Capacity
• Maximal Inspiratory Pressure
• Work of Breathing
• Gas Exchange
• PaO2/FiO2, PaO2/PAO2, P(A-a)O2
• Minute Ventilation
Weaning Parameters are not
• Deadspace
predictive! Meade, et al, Chest 2001.
120: 400S-424S
To RSBI or Not?
Control (n=151): f/Vt was measured and
used (threshold of 105 breaths/min/L)
 Weaning time significantly shorter in the
group where f/Vt was not used (2.0 vs
3.0 dyas, p=0.04)
 No difference in extubation failure,
hospital mortality rate, tracheostomy, or
unplanned extubation.
Tanios, Critical Care Med 206. 34:2530
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Spontaneous Breath Trials
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T-piece, PSV (7 cm H2O), Tube Compensation
equally acceptable for SBT (Estaban et al, Am J
Resp Crit Care Med 1997. 156: 459).
Spontaneous breathing trial can be applied on
ventilator (0/0 SBT)
30 minutes is adequate for spontaneous breathing
trial (Esteban et al, Am J Respir Crit Care Med 1999.
159:512).
CPAP with 5 cm H2O can produce false positive trial
with COPD and CHF.
THE BEST WEANING PARAMETER IS A
SPONTANEOUS BREATHING TRIAL.
Weaning Parameters
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See Chart Provided
 Wide variation between sources
 Study “Pilbeam” column on chart (Table 20-1 p. 412)
Problems with weaning parameters
 They are not reproducible or reliable if they are therapist
dependent.
 VC & MIP
 Best parameters are patient driven.
 R.S.B.I.
 P0.1
 Spontaneous rate
 Spontaneous tidal volume
 Vital signs
Occlusion Pressure
Measurements
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P0.1s or P100
Occlude airways for first 100 msec
and measure pressure.
Index of ventilatory drive.
Fast-twitch vs. slow-twitch fibers of
diaphragm.
Pressure-Time Product
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Comparison of transdiaphragmatic
pressure and maximal inspiratory
pressure.
What percentage of the maximal
inspiratory pressure is being used for a
“normal” breath.
Use of specialized esophageal catheter
with two balloons positioned above &
the diaphragm (Fig.10-25, p. 196).
Part 2
Evidence-Based Guidelines for
Weaning and Discontinuing
Ventilatory Support
Reprinted in Respiratory Care 2002;
47(1):69-90)
Grades of Evidence
A Scientific evidence provided by well-designed,
well-conducted, controlled trials (randomized and
nonrandomized) with statistically significant
results that consistently support the guideline
recommendation.
B Scientific evidence provided by observational
studies or by controlled trials with less
consistent results to support the guideline
recommendation.
C Expert opinion supported the guideline
recommendation, but scientific evidence either
provided inconsistent results or was lacking.
Guideline 1
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(Grade B)
In patients requiring mechanical ventilation
for > 24 hours, a search for all the causes
that may be contributing to ventilator
dependence should be undertaken.
This is particularly true in the patient who
has failed attempts at withdrawing the
mechanical ventilator.
Reversing all possible ventilatory and nonventilatory issues should be an integral part
of the ventilator discontinuation process.
“Reversing all possible ventilatory
and non-ventilatory issues”
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Why was the patient placed on the
ventilator in the first place?
Why won’t they come off the ventilator?
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Neurological Issues
Respiratory system muscle (load &
interaction)
Metabolic factors
Gas exchange factors
Cardiovascular factors
Psychological factors
Guideline 2 (Grade B)

Patients receiving mechanical
ventilation for respiratory failure should
undergo a formal assessment of
discontinuation potential if the
following criteria are satisfied:
Criteria:
Evidence of some reversal of the underlying
cause of respiratory failure.
Adequate oxygenation
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PaO2/FiO2 > 150-200.
Requiring positive end-expiratory pressure [PEEP]
< or = 5-8 cm H2O
FiO2 < or = 0.4 - 0.5
pH > or = 7.25
Hemodynamic stability as defined by:
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the absence of active myocardial ischemia.
the absence of clinically important hypotension.
no vasopressor therapy or therapy with only lowdose vasopressors such as dopamine or
dobutamine < 5 micro g/kg/min.
The capability to initiate an inspiratory effort.
Assessment of Discontinuation
Potential
A – acid/base normalized for patient
B – bronchospasm controlled
C – cardiac problems controlled (CHF, rhythm, BP…)*
D – drugs for sedation limited or eliminated
E – electrolytes & fluids in balance
H – hemoglobin >10 gms%
I – infection reversed (MV & temp WNL)
N – nutrition appropriate
E – endocrine function acceptable (thyroid & pituitary)
S – sleep & secretions under control
Guideline 3 (Grade A)
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Formal discontinuation assessments for
patients receiving mechanical ventilation for
respiratory failure should be done during
spontaneous breathing rather than while
the patient is still receiving substantial
ventilatory support.
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An initial brief period of spontaneous breathing
can be used to assess the capability of
continuing onto a formal SBT.
Spontaneous breathing trial
(SBT)
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Most patients on ventilators do not
require formal “weaning”.
The tolerance of a formal SBT for 30
– 120 minutes should prompt
consideration for permanent ventilator
discontinuation.
 Studies have shown a 77% weaning
success rate with this criteria.
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Methods for performing a
spontaneous breathing trial (SBT)
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Low level Pressure Support (5-7
cm H2O) with or without PEEP.
Automated Tube Compensation
with or without PEEP.
T-bar (no alarms, more equipment,
high Raw).
Comparison of Weaning
Methods
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Brochard, Am J Respir Crit Care Med
1994. 150:896.
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Patients screened for weaning readiness.
T-piece trial for 2 hours; ~75% tolerated
and extubated.
Greatest success for PSV (worst for SIMV)
Automatic Tube Compensation:
Do We Need It?
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Does not compensate for changes in resistance that
occur in vivo; e.g. kinking or secretions.
Estaban, Am J Respir Crit Care Med1997. 156:459
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Straus, Am J Respir Crit Care Med 1998; 157:23
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PSV or T-piece acceptable for SBTs.
Spontaneous breathing through ET tube mimics work of
breathing after extubation.
Haberthur, Acta Anaesthesiol Scan 2002. 46:973
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No difference in patient tolerance of SBT between patients
randomized to TC, PSV of 5 cm H2O or T-piece.
Formal Discontinuation
Assessment
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Respiratory pattern
Adequacy of gas exchange
Hemodynamic stability
Subjective comfort
Formal Discontinuation
Assessment
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Are respiratory muscles capable
of sustaining spontaneous
breathing?
Ventilatory pattern
f </= 30 – 35
 f not changed > 50%
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No increased work of breathing
Use of accessory muscles
 Thoracoabdominal paradox
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Assessment of
Discontinuation Potential
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Are there conditions that can contribute
to respiratory muscle fatigue?
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Hyperinflation
Malnutrition
Hypoxemia
Acidosis
Electrolyte imbalance
Endocrine disorders
Drugs (paralytics & steroid combos)
Neuromuscular problems
Objective Measures
Indicating Tolerance
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Gas exchange
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SpO2 >/= 85 – 90%
PaO2 50 – 60 mmHg
pH >/= 7.32
PaCO2 increase no more than 10 mmHg.
Hemodynamics
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HR < 120 – 140
HR change <20%
No vasopressors required.
Subjective Measures
Indicating Tolerance
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Mental state
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No somnolence, coma, agitation,
anxiety.
No onset or worsening discomfort
or dyspnea.
No diaphoresis.
Guideline 4 (Grade C)
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The removal of the artificial airway
from a patient who has successfully
been discontinued from ventilatory
support should be based on
assessments of airway patency and
the ability of the patient to protect the
airway.
Reference Material
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AARC – Clinical Practice Guideline
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Removal of the Endotracheal Tube –
2007 Revision & Update
Extubation

REMEMBER: Weaning from
ventilatory support does not mean
the patient is ready for extubation.
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Assessments of airway patency
Review history
 Do cuff leak test
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Assessment of ability of the patient to
protect the airway
Amount of secretions
 Ability to cough & gag
 Level of consciousness
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Guideline 5 (Grade A)
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Patients receiving mechanical
ventilation for respiratory failure who
fail an SBT should have the cause for
the failed SBT determined.
Once reversible causes for failure are
corrected, and if the patient still meets
the criteria, subsequent SBTs should
be performed every 24 hours.
Guideline 6 (Grade B)
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Patients receiving mechanical
ventilation for respiratory failure who
fail an SBT should receive a stable,
non-fatiguing, comfortable form of
ventilatory support.
Guideline 7 (Grade A)
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Anesthesia/sedation strategies and
ventilator management aimed at early
extubation should be used in postsurgical patients.
Guideline 8 (Grade A)
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Weaning/discontinuation protocols
designed for non-physician health care
professionals (HCPs) should be
developed and implemented by ICUs.
Protocols aimed at optimizing sedation
should also be developed and
implemented.
2. Discontinuation
assessment
1. Evaluate
discontinuation
potential
3. Evaluate extubation potential
Guideline 9 (Grade B)
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Tracheotomy should be considered after an
initial period of stabilization on the ventilator
when it becomes apparent that the patient
will require prolonged ventilator assistance.
Tracheotomy should then be performed
when the patient appears likely to gain one
or more of the benefits ascribed to the
procedure.
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Patients who may derive particular benefit
from early tracheotomy are the following:
Those requiring high levels of sedation to
tolerate translaryngeal tubes.
Those with marginal respiratory mechanics
(often manifested as tachypnea) in whom a
tracheostomy tube having lower resistance
might reduce the risk of muscle overload.
Those who may derive psychological benefit
from the ability to eat orally, communicate
by articulated speech, and experience
enhanced mobility; and
Those in whom enhanced mobility may
assist physical therapy efforts.
Guideline 10 (Grade B)
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Unless there is evidence for clearly
irreversible disease (e.g., high spinal
cord injury or advanced amyotrophic
lateral sclerosis), a patient requiring
prolonged mechanical ventilatory
support for respiratory failure should
not be considered permanently
ventilator dependent until 3 months
of weaning attempts have failed.
Permanently Ventilator
Dependent
Examples:
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Irreversible diseases:
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High spinal cord injury
Advanced amyotropic lateral sclerosis (ALS)
Polio & postpolio sequelae
Incurable diseases
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COPD
Kyphoscoliosis
Pulmonary Fibrosis
Guideline 11 (Grade C)

Critical-care practitioners should familiarize
themselves with facilities in their communities, or
units in hospitals they staff, that specialize in
managing patients who require prolonged
dependence on mechanical ventilation.
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Such familiarization should include reviewing published
peer-reviewed data from those units, if available.
When medically stable for transfer, patients who have
failed ventilator discontinuation attempts in the ICU
should be transferred to those facilities that have
demonstrated success and safety in accomplishing
ventilator discontinuation.
Guideline 12 (Grade C)
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Weaning strategy in the permanent
mechanical ventilator patient should
be slow-paced and should include
gradually lengthening self-breathing
trials.
Prolonged Mechanical
Ventilator (PMV) patient
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Consider use of Passy-Muir Valve
Use slow paced trials
 Gradually increase self-breathing trials
 Often used when partial support
ventilation is providing ½ the support
needed by the patient
 Awake, alert, stable patient able to
manage secretions
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Part 3
End of Life Issues
Advanced Directives
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Legal documents – written, signed, witnessed and
notarized
Examples:
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Living Will - Gives health care providers guidelines
regarding the wishes of the patient in the event that the
patient is no longer of sound mind and cannot make
decisions regarding his care.
“Do Not Resuscitate” order (DNR) – Provides guidance
when the heart stops or the patient stops breathing.
“Chemical Code Only”
“Do Not Intubate”
“Do Not Shock”
“Withhold Nutrition & Hydration” (consult state law)
Durable Power of Attorney
(DPA) for Health Care
Decisions
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Person designated to make health care
decisions for the patient should the patient
become incapacitated.
If person not designated the law recognizes
hierarchy of relationships
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Parents or legal guardian of minor
Durable Power of Attorney
Spouse
Adult children (all must agree)
Parents of patient
Adult siblings (all must agree)
Sustaining vs. Comfort Care
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Terminally ill patients should be made as
comfortable as possible (palliative care).
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Observe for agitation and grimacing.
Use adequate doses of sedatives & analgesics.
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Excessive dosing to hasten death in not allowed (causing
apnea or cardiac arrest).
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Allow open family visitation if possible.
Minimize monitoring & alarms.
Stop testing (labs, x-rays…).
End of Life Issues
Criteria for Terminal Weaning:
1. Patient’s informed consent.
2. Medical futility (in last 100 cases,
treatments were useless).
3. Reduction of pain and suffering.
End of Life Issues
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Handouts:
Brain Death Criteria
 Apnea Testing Procedure
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End of Life Issues
Criteria for Determination of Brain Death:
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No hypothermia.
No purposeful movement to stimulation.
Absence of brain stem reflexes.
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Pupils fixed.
No corneal reflex.
No cough or gag.
Absence of doll’s eyes.
No toxins or drug effects.
Apnea Testing or Negative Brain Flow Study.
Doll’s Eye Sign

An indicator of brain stem dysfunction, the
absence of the doll's eye sign is detected by
rapid, gentle turning of the patient's head
from side to side.

The eyes remain fixed in midposition, instead
of the normal response of moving laterally
toward the side opposite the direction the
head is turned.
Doll’s Eye Sign

The absence of doll's eye sign indicates injury to the
midbrain or pons, involving cranial nerves III and VI.

It typically accompanies coma caused by lesions of
the cerebellum and brain stem.

This sign usually can't be relied upon in a conscious
patient because he can control eye movements
voluntarily.
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Absent doll's eye sign is necessary for a diagnosis of
brain death.
End of Life Issues
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An example of an Apnea Test for
determination of brain death:
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Patient placed on 100% O2.
Rate decreased so PetCO2 >40 mmHg.
Patient removed from vent and put on
100% O2.
After 2 minutes draw an ABG & patient
returned to ventilator.
OBJECTIVE: Demonstrate lack of
spontaneous breathing in presence of
PaCO2 >60 mmHg and no hypoxemia.
Protocols
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Homework Assignment:

Get a copy of the ventilator weaning
protocol from the institution where
you work or are doing your clinical
rotation.
LONG-TERM VENTILATION &
TRANSPORT
Objectives
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State the goals of mechanical ventilation in an alternate
environment.
Name the factors used to estimate the cost of home
mechanical ventilation.
Describe facilities used for long-term mechanical
ventilation.
Compare the criteria for discharging a child versus
discharging an adult who is ventilator dependent.
Describe other forms of ventilation for the long-term
ventilator dependent patient.
Categories of Patients Requiring
Long-Term Ventilation
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Those recovering from an acute illness.
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Those recovering from a chronic illness.
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Guillain-Barre
COPD
Kyphoscoliosis
Both have high mortality
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2-year mortality of 57%.
5-year mortality of 66-97%.
Factors Associated with
Increase in VAIs
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Ventilator-Assisted Individuals
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Individuals requiring MV for at least 6
hours/day for 21 days or more. (ACCP)
Improvements in technology have led to
increased survival of critically ill
patients.
Increased emphasis on reducing costs
by transferring patients out early.
Factors Associated with
Increase in VAIs
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NIV is a effective alternative to invasive
ventilation.
Simpler and more versatile equipment
are now available.
Increased availability of LTACs and
other agencies that allow for ventilation
in the home or other SNFs.
Example: Christopher Reeves
Goals of LTMV
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Enhancing the individual’s living
potential.
Improving physical and physiological
level of function.
Reducing mortality.
Reducing hospitalizations.
Extending life.
Providing cost-effective care.
Sites for LTMV
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Acute-Care Sites
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Intermediate-Care Sites
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ICU or specialized respiratory-care units.
General Medical-Surgical floors.
LTACs
Sub-Acute Units
Long-term care hospitals
Rehabilitation Hospitals
Long-Term Care Sites
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SNFs
Single-Family homes
Patient Selection for LTMV
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Disease Process & Clinical Stability
Acute illness/ARF who aren’t
responding to conventional liberation
techniques.
 Chronic disorders who need support
only during certain times of the day.
 Need for continuous support.

CVA
 Diaphragmatic paralysis
Box 21-2 pg. 429
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Patient Selection for LTMV

Psychosocial Factors
Prior to discharge.
 Family awareness and preparedness.
 Psychological evaluation.
 Other support systems.

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Respite Care
Patient Selection for LTMV

Financial Considerations
High cost regardless of site.
 Multiple factors:

Diagnosis.
 Level of acuity.
 Need for rehabilitation services.
 Need for monitoring.
 Oxygen & medications.
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Preparation for Discharge
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Assessment
Education
Training
Plan of Care
Preparation for Discharge
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Multi-disciplinary
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Primary Care Physician
Pulmonologist
Nurse
RT
Social Worker/Discharge Planner
PT
OT
Speech Pathologist
Dietician
DME
Geographic & Home
Assessment
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Proximity to home care services.
Modifications to Home.
Mapping of electrical circuits. (Box
21-4, pg. 433)
Training
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Family Education
Detailed, written instructions.
 Equipment & troubleshooting.
 Disinfection.
 Status change recognition.
 Return demonstration.

Follow-Up

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Especially important in infants &
children because of changes due to
growth and development.
Adequate nutrition.
Family/Social issues.
Alternatives to Invasive Mechanical
Ventilation in the Home
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Non-invasive Positive Pressure
Negative-Pressure Ventilation
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Iron lung
Chest Cuirass
Body Suit
Rocking Bed
Pneumobelt
Diaphragmatic Pacing
Complications of Long-Term
Mechanical Ventilation
Fig. 21-6
p. 440
Transport
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Necessity
Monitoring
Evaluation of Transport Team
Transport Ventilator
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MRD
Critical Care Ventilator
Transport Ventilator
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LTV
Dräger