Transcript Titration Protocols

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Titration Protocols
BY
AHMAD YOUNES
PROFESSOR OF THORACIC MEDICINE
Mansoura Faculty of Medicine
INDICATIONS TO TREAT WITH POSITIVE AIRWAY PRESSURE
• Administration of positive airway pressure therapy
is the treatment of choice for most patients with
OSA.
• CPAP treatment is generally recommended for all
patients with an AHI greater than or equal to
15/hour and for symptomatic patients (eg,
excessive daytime sleepiness, insomnia, impaired
cognition, mood disorder, hypertension, ischemic
heart disease, or stroke) with an AHI between 5–
15/hour.
Treatment modalities for positive airway pressure
• Continuous positive airway pressure Provides a constant
pressure throughout the respiratory cycle
• Bi-level positive airway pressure Provides two pressure
levels during the respiratory cycle: a higher level during
inspiration and a lower pressure during expiration
• Autotitrating positive airway pressure Provides variable
pressures using device-specific diagnostic and therapeutic
algorithms. (Auto CPAP, Auto BPAP )
• Nocturnal noninvasive positive pressure ventilation
Provides two pressure levels at a set rate to assist
ventilation.
Mechanism of Action
• Positive airway pressure, via a fan or turbine generated
flow of air, function as a pneumatic splint that maintains
the patency of the vulnerable portions of the
nasopharyngeal airway.
• Positive airway pressure increases nasal pressure above
critical pressure ( Pcrit).
Determining optimal CPAP
• A variety of methods have been used to determine a
single optimal CPAP level. These include:
1. In-laboratory attended polysomnographically guided
CPAP titration
– Full-night studies.
– Split-night studies (consists of an initial
diagnostic portion and a subsequent CPAP
titration on the same night);
2. Unattended laboratory or home titration
3. Use of autotitrating devices .
4. Formula-derived pressures from clinical,
polysomnography (PSG), and/or anthropometric variables
Determining optimal CPAP
• The current standard of practice involves an attended
pressure titration during a laboratory PSG, during which
sleep stages and respiratory variables are monitored.
• The goal is to determine a single fixed pressure that
eliminates apneas, hypopneas, snoring, and respiratory
effort–related arousals (RERAs); maintains adequate
oxygen saturation; and improves sleep architecture and
quality in all sleep positions and in all sleep stages.
• It is generally accepted that higher pressures are required
to reverse airway occlusion during REM sleep and during
sleep in a supine position.
• Split-night studies can potentially underestimate the
severity of OSA
Criteria for split night CPAP titration
• At least 2 hours of recorded sleep time during the
initial diagnostic portion of the study Apneahypopnea indices during the diagnostic portion of
the study: AHI >40 OR AHI =20–40 (accompanied
by significant oxygen desaturation .
• At least 3 hours are available for CPAP titration
with the presence of REM sleep during a supine
sleep position
American Academy of Sleep Medicine (AASM) recommendations for CPAP
and BPAP therapy for adult patients with sleep related breathing disorders
• The presence of OSA based on an acceptable diagnostic method
should be established prior to CPAP therapy (standard).
• Indications for CPAP therapy include:
a. Moderate to severe OSA (standard)
b. Mild OSA (option)
c. Improvement of subjective sleepiness in patients with OSA (standard)
d. Improvement of quality of life in patients with OSA (option)
e. As an adjunctive therapy to lower blood pressure in patients with OSA
(option)
• The preferred CPAP titration method to determine optimal positive
airway pressure is an in-laboratory, full-night, attended
polysomnography, but split-night (initial diagnostic and subsequent
titration portion) studies are usually adequate (guideline).
• Objective monitoring of CPAP use is recommended to ensure optimal
utilization (standard).
American Academy of Sleep Medicine (AASM) recommendations for CPAP
and BPAP therapy for adult patients with sleep related breathing disorders
• Close monitoring of CPAP utilization and any problems that might
develop, especially during the first few weeks of use, is important, as is
the correction of problems if needed (standard).
• Addition of heated humidification and a systematic educational
program enhance adherence to CPAP use (standard).
• Patients with OSA treated with CPAP therapy should be followed up
yearly or more frequently as needed to correct problems related to its
use (option).
• CPAP and bilevel positive airway pressure (BPAP) therapy are
generally safe with minor adverse effects (standard).
• BPAP can be considered as an optional therapy to CPAP in selected
patients who require high pressures, who report difficulty exhaling
against a fixed CPAP pressure, or who have coexisting central
hypoventilation (guideline).
• BPAP may also be beneficial in patients with some forms of restrictive
lung disease or hypoventilation syndromes with daytime hypercapnia
(option).
Beneficial effects of positive airway pressure therapy in OSA
Upper airway anatomy and function
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Reduction or elimination of upper airway collapse
Reduction or elimination of snoring
Decrease in apnea-hypopnea index (AHI)
Increase in arterial oxygen saturation (SaO2)
Sleep quality
• Decrease in sleepiness (subjective and
objective)
• Decrease in number of arousals and improvement in
sleep quality .
Enhancement of neuro-cognitive function
Improvement in mood and quality of life
Beneficial effects of positive airway pressure therapy in OSA
• Improvement in driving simulator steering
performance .
• Improvement in blood pressure and heart rate
profiles.
• Improvement in cardiac function .
• Reversal of the increase in mortality associated
with sleep apnea .
• Reduction in physician claims and hospital stay
Adverse consequences of positive airway
pressure therapy
• Aerophagia and gastric distention
• Barotrauma (eg, pneumothorax, pneumomediastinum,
pneumocephalus)
• Chest discomfort and tightness
• Claustrophobia, sensation of suffocation or difficulty
with exhalation
• Eye irritation (conjunctivitis)
• Facial skin irritation, rash or abrasion
• Mask and mouth leaks
• Nasal congestion, dryness, epistaxis or rhinorrhea
• Sleep disruption due to noise from the device
• Sinus discomfort or pain
Adherence to Positive Airway Pressure Therapy
• A large proportion of patients report not being able to
tolerate the device.
• Self-reports often over estimate actual CPAP use.
• Therapeutic adherence in the different studies has
varied from 46% to 80% of patients who use CPAP for 4
or more hours nightly on at least 70% of monitored
nights.
• Factors influencing long-term use include snoring
history, severity of illness (AHI), perceived benefit from
therapy, and self-reported sleepiness (Epworth
Sleepiness Scale [ESS]).
Adherence to Positive Airway Pressure Therapy
• Patterns of nightly use are often discernible by the first
few days or weeks of initiating treatment .
• Adherence to CPAP therapy may be improved with
education (eg, additional home visits, participation in
group clinics, periodic phone calls to uncover any
problems and to encourage use, and even simple
written information on the importance of regular CPAP
use), airway humidification, proper selection of the
CPAP interface, desensitization procedures for CPAP,
early follow-up, prompt and aggressive management of
adverse effects related to CPAP use, and regular
assessment of CPAP adherence.
Techniques that may increase CPAP utilization
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CPAP education and support
Humidification
Correction of nasal problems
Nasal vs. full-face masks
Sedative-hypnotics
C-flex
BPAP
Other Modes of Positive Airway Pressure
A ) Autotitrating positive airway pressure
• Because the required positive airway pressure can differ
considerably with sleeping posture and sleep stages,
optimal positive airway pressure may have significant
intra-night and inte-rnight variability. The causes of this
variability are
1-Changes in percentage of REM sleep
2-Changes in percentage of different sleep positions
(supine vs. non supine)
3-Changes in nasal resistance (eg, congestion)
4-Use of muscle relaxants, sedatives and opioids .
5-Change in weight
Auto-titrating positive airway pressure (APAP)
• Auto-titrating positive airway pressure (APAP) devices
automatically and continuously Adjust the delivered
pressure, as required, to maintain airway patency.
• Pressure is increased if apneas, hypopneas, airflow
limitation or snoring are present, or is gradually reduced
if no respiratory events are detected over a
predetermined period.
• These devices have been used to help identify a fixed
single pressure for subsequent treatment with a
conventional CPAP device (APAP titration) or in a selfadjusting mode for nightly therapy of OSA (APAP
treatment).
Auto-titrating positive airway pressure
• Studies have shown no significant differences between
conventional in-laboratory CPAP titration and APAP
titration in reductions of AHI and arousal indices,
changes in sleep architecture, oxygenation, or
subsequent CPAP acceptance.
• APAP treatment has been demonstrated to be
comparable to conventional constant-pressure CPAP
therapy.
• Different devices may utilize different algorithms for
monitoring respiratory events (eg, snoring, airflow
limitation, apnea-hypopneas, or impedance) and for
altering delivered pressures.
Advanced methods of auto-titration
• Newer generation devices can increase the IPAP alone
in order to ameliorate obstructive events (Auto Bi-level
PAP),correct hypoventilation (averaged volume assured
pressure support [AVAPS], Intelligent Volume Assured
Pressure Support (iVAPS ) or combine Auto Bi-level
PAP with auto-CPAP (Auto-trilevel) or combat central
apneas in patients with complex sleep apnea (ServoVentilation).
• Devices may also introduce a back-up rate to prevent
central apneas and although in general they are not
referred to as APAP devices, they function using similar
principles and can be judged as the latest generation of
APAP devices .
Autobilevel positive airway pressure with a
minimum EPAP of 6 cm H2O and a maximum
IPAP of 25 cm H2O.
BiPAP AVAPS and VPAP™ ST with iVAPS
BiPAP AVAPS
BiPAP A40 Ventilator
• BiPAP A40 comes with well-known and
clinically proven Philips Respironics
technology such as Auto-Trak, AVAPS
and a Dry Box humidifier design.
• The device is capable of non invasive
and invasive pressure ventilation, up to
40 cmH2O, providing treatment for your
chronic respiratory insufficiency
patients.
• The device features AVAPS-AE, the
first fully automatic ventilation mode,
designed to help clinicians during
titration process, while maintaining
comfort and therapy optimization at the
lowest pressures.
BiPAP A40 Ventilator
• This new innovative ventilation mode helps in providing
long term therapy compliance regardless of changes to
the body position, sleep stages and respiratory
mechanics.
• Detachable Battery with up to 5 Hours Backup
• AVAPS-AE Automatically Adjust Ventilation to the
Patients Need
• Compatible with PSG Systems
• Optional Oximetry Module
• Intuitive, User Friendly & Colored Interface
• Integrated Heated Humidifier
• Graphical & Statistical Data Management on Encore Pro
& Direct View Soft wares
SPECIFICATIONS
• Ventilation modes : CPAP, S, S/T, PC, T, AVAPS-AE
• Hybrid ventilation AVAPS (Average Volume Assured
Pressure Support) AVAPS-AE
• IPAP 4 – 40 cm H2O
• EPAP 4 – 25 cm H2O
• Target tidal volume (when AVAPS enabled) 200 – 1500
ml
• Breath rate 0 – 40 bpm (4 – 40 bpm in T mode)
• Inspiratory time 0.5 – 3 sec.
• Triggering and cycling Auto-Trak ,Sensitive Auto-Trak,
Flow triggering.
• Rise time 1 (100 ms) – 6 (600 ms)
• Size 21.6 cm W x 19 cm L x 11.5 cm H
• Weight 2.1 Kgs (with power supply)
SPECIFICATIONS
• Humidification System One humidity control and ‘Dry Box’
technology
• Alarms Patient disconnection Apnea ,Low minute ventilation ,Low
tidal volume (with AVAPS/AVAPS-AE only) ,High RR
• Monitoring Pressure, tidal volume, minute ventilation, respiratory
rate, leak, I/E ratio
• Battery back up Detachable battery module: 5 hours
• DC power source 12 VDC, 5.0 A (external battery),
24 VDC, 4.2 A (power supply)
• Data management Encore Pro 2 and Direct View software
• Compatible with oximetry module
• Advanced detection of residual respiratory events(Obstructed
Airway Apnea, Clear Airway Apnea, Hypopnea, Periodic Breathing,
RERA, Large Leak and Snore)
VPAP™ ST with iVAPS
Why Alveolar Ventilation?
• Gas exchange only occurs at alveolar level
• We have a continuous demand for a supply of
O2 and removal of CO2
• Conducting airways do NOT participate in gas
exchange
Anatomical Dead space
• Inspired/expired air remaining in conducting
airways
• Not involved in gas exchange
• Correlation between patient’s height and dead
space (Vd)
• Height is used to calculate anatomical dead
space (Vd) for each breath of air (Tidal Volume)
• Example dead space volume (Vd) : 120 ml for
height 175 cm or 70 inches
Anatomical dead space in relation to
height of the patient
Alveolar Ventilation
• Vt (500ml) – Vd (120ml) = alveolar ventilation for one
breath
• 500 - 120 = 380 ml participates in gas exchange for each
breath
• Vta x RR (respiratory rate) = Va (minute alveolar
ventilation) = 0.380 x 15 = 5.7L/min
Benefits Of Alveolar Ventilation
• Supply of O2 (PaO2) .Normal = 80 – 100 mm Hg
• Removal of CO2 (PaCO2) . Normal = 35 – 45 mm Hg
• Alveolar ventilation provides necessary gas exchange to
satisfy metabolic demand
As alveolar ventilation drops , iVAPS rapidly increase pressure
support until target Va is reached, and as alveolar ventilation
increase , iVAPS rapidly decrease pressure support .
Intelligent back up rate (iBR) stays out of the way at 2/3 spontaneous rate
whenever the patient spontaneously triggers above 2/3 of the target . once
the patient rate reach minimum back up rate (2/3 of the target ) iBR increase
towards patient spontaneous rate to maintain alveolar ventilation .Once
spontaneous trigering returns, iBR drops back to 2/3 of the target /
spontaneous rate.
Auto-TriLevel
• The auto-TriLevel principle by Weinmann combines two
proven types of therapy – auto-CPAP and BiLevel – into
a synthesis that offers the most therapy effectiveness.
Your benefits with these products:
• Therapeutically effective maximum and mean pressures
that are lower than BiLevel with the same tidal volume
for fewer side effects such as leakage.
• It‘s like a new titration every day – adjusts to patient‘s
high variability .
• Effortless titration and monitoring .
Auto-TriLevel
• IPAP: inspiratory pneumatic
splinting of the airways
(ventilation)
• EPAP: easier exhalation at a low
expiratory pressure level for a
pleasant breathing sensation
• Additional end-expiratory
pressure (EEPAP): required
minimum pressure for adequate
splinting of airways during phase
when risk of collapse is highest
• PDIFF (Δ IPAP-EPAP): needoriented ventilation support by
means of changes between
inspiratory (IPAP) and expiratory
(EPAP) pressure levels
Auto-TriLevel
• Reduced mean and maximum therapy pressure
under TriLevel: Results of a bench test
comparison with BiLevel therapy.
• SOMNOvent auto-ST is the world‘s first automatic
BiLevel device that permits goal-oriented therapy
settings(SCOPES).
• With the combination of the autoTriLevel principle and
the automatic trigger WM trak, this device delivers the
greatest effectiveness, reliability and breathing comfort
– simply the fastest therapy results.
• Particularly for cases of complicated SDB, SOMNOvent
auto-S, convinces with its intelligent combination of
automatic BiLevel S therapy and auto-CPAP.
Auto-TriLevel
• Auto-bilevel spontaneous (SOMNOvent auto-S ).
• Auto-bilevel spontaneous/timed (SOMNOvent
auto-ST ).
• Anti-cyclic modulated ventilation (SOMNOvent
auto-CR ).
Stellar TM 150
Stellar provides the following modes:
• CPAP mode—a fixed pressure is delivered.
• S (Spontaneous) mode—the device senses the patient
breath and triggers IPAP in response to an increase in
flow, and cycles into EPAP at the end of inspiration. The
breath rate and the respiratory pattern will be
determined by the patient.
• ST (Spontaneous/Timed) or PS (Pressure Support)
mode—the device augments any breath initiated by the
patient, but will also supply additional breaths should
the patient breath rate fall below the clinician's set
’backup’ breath rate.
• T (Timed) mode—the fixed breath rate and the fixed
inspiration time set by the clinician are supplied
regardless of patient effort.
Stellar provides the following modes:
• PAC (Pressure Assist Control)—the inspiration time is
preset in the PAC mode. There is no spontaneous/flow
cycling. The inspiration can be triggered by the patient
when respiratory rate is above a preset value, or time
triggered breaths will be delivered at the backup breath
rate.
• iVAPS (intelligent Volume Assured Pressure Support)
designed to maintain a preset target alveolar ventilation
by monitoring delivered ventilation, adjusting the
pressure support and providing an intelligent backup
breath automatically. The iVAPS therapy mode is
indicated for patients 66 lb (30 kg) and above.
iVAPS (intelligent Volume Assured Pressure Support)
• The iVAPS therapy mode is indicated for patients 30 kg
and above.
• You may prefer some assurance that the patient's
ventilatory needs will be maintained if their condition
varies.
• A variety of ‘dual mode’ schemes exist, that aim to
combine the benefits of pressure target and volume
target, most of which can be categorized generically as
volume assured pressure support, or VAPS modes.
• With VAPS devices in general, the ventilatory assistance
(pressure support) aims to automatically adjust to
changes in patient condition over time, typically to
maintain a target tidal volume.
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iVAPS (intelligent Volume Assured Pressure Support)
iVAPS offers the comfort and synchrony of pressure
support, but with the assurance offered by a volume target.
iVAPS has the following advantages over traditional VAPS
schemes:
iVAPS is a unique combination for a servo-controlled
ventilator, in that iVAPS has the goal of regulating alveolar
ventilation to a prescribed target, and iVAPS has a rapid but
gentle servo-control response.
iVAPS is tuned to be fast enough to avoid blood-gas
derangement associated with most breathing challenges,
including during sleep, but is gentle enough to avoid
disruption.
iVAPS has an intelligent Backup Rate (iBR) which aims to
keep ‘out of the way’ while the patient is breathing, yet
during sustained apnea will mimic the patient's own breath
Pathology Defaults
• A choice of disease-specific preset values, based
on commonly-used clinical values for obstructive,
restrictive , obesity hypoventilation and normal
lung mechanics.
• Advanced settings are optimized so medical staff
can focus on fine-tuning primary settings for each
patient.
• Before use you will need to review the set
parameters on the Clinical Settings screen.
Pathology Defaults
SomnoVent CR
Respironics autoSV
ResMed VPAP Adapt SV
ASV is a variant of BPAP that was developed to treat Cheyne-Stokes
central apnea.
Both ASV and BPAP devices with a backup rate are approved for use
with patients with central apnea and complex sleep apnea
AASM recommendations for autotitrating CPAP
for OSA (STANDARD)
1. The presence OSA must be diagnosed using an
acceptable method.
2. APAP titration or treatment is not indicated for patients
with the following medical conditions: Congestive heart
failure, Significant respiratory diseases such as COPD
or daytime hypoxemia and respiratory failure from any
cause, nocturnal arterial oxygen desaturation secondary
to disorders other than OSA (eg, OHS)
3. Non snorers should not be titrated with APAP devices
using diagnostic algorithms that rely on vibration or
sound production.
AASM recommendations for autotitrating CPAP
for OSA (STANDARD)
4. APAP devices are not recommended for splitnight CPAP titration.
5. Patients who are being treated with APAP or
with fixed CPAP based on APAP titration should
be monitored for effectiveness and safety of
therapy.
6. If APAP or CPAP therapy is considered
ineffective (ie, symptoms fail to resolve), reevaluation and standard attended CPAP titration
should be performed.
AASM recommendations for autotitrating
CPAP for OSA (GUIDELINE)
• Certain APAP devices may be used to determine a
single CPAP pressure during attended
polysomnography for the therapy of OSA (APAP
titration).
• Certain APAP devices may be used in a self-adjusting
mode for the therapy of OSA after an initial successful
attended polysomnography-guided CPAP or APAP
titration (APAP treatment).
OPTION
1. The use of unattended APAP to determine pressures for
fixed CPAP or to treat CPAP-naive patients in a selfadjusting APAP mode has not been established.
B ) Bilevel positive airway pressure
• BPAP devices provide two pressure levels during the
respiratory cycle, namely a higher level during
inspiration (inspiratory positive airway pressure; IPAP)
and a lower pressure during expiration (expiratory
positive airway pressure; EPAP).
• Patients with OSA who have persistent oxygen
desaturation due to hypoventilation despite CPAP
therapy may benefit from BPAP.
• When used for patients with OSA, levels of EPAP are
titrated to eliminate apneas, and IPAP is progressively
increased until hypopneas and snoring are controlled.
Representative tracings of flow, tidal volume, and
airway pressure (Paw) during administration of
continuous positive airway pressure (CPAP) and
bi-level PAP
BPAP may also be considered for
• Patients with OSA who are unable to tolerate
CPAP and complain of being unable to breathe
out against high CPAP expiratory pressures,
significant mouth leaks or aerophagia,
• Those with concurrent chronic obstructive
pulmonary disease (overlap syndrome),or
• Those in whom hypoventilation (eg, OHS or
neuromuscular weakness) is suspected.
C ) Noninvasive positive pressure ventilation
• Noninvasive positive pressure ventilation
(NIPPV) may be required in selected patients
with persistent sleep-related hypoventilation
and CO2 retention despite therapy with CPAP
and supplemental oxygen.
• NIPPV, which can be provided using a volumecycled ventilator, can improve ventilation and
arterial blood gas values during both
wakefulness and sleep.
• Some patients on NIPPV are able to resume
CPAP therapy at a later time.
TITRATION
TECHNIQUES
General Titration Considerations
• The current standard of care dictates CPAP therapy be
commenced and titrated under direct supervision by a
trained technician.
• Direct supervision allows for immediate assessment of
various sleep-related disturbances, direct determination
of the optimal CPAP pressure, and identification of
significant sleep-related co-morbidities, including but
not limited to nocturnal seizures, cardiac arrhythmias,
parasomnia activity, nocturnal myoclonus, persistent
hypoxemia with PAP therapy in the absence of overt
respiratory events, which may in turn require additional
titration of supplemental oxygen.
General Titration Considerations
• A polysomnography (PSG) is the standard
method for PAP titration and is usually
accomplished either as the second part of a split
study or during an entire night after a previous
diagnostic study.
• A split study is recommended only if the AHI is
greater than 40/hr and 2 hours of monitoring
have occurred. In addition, 3 hours of PAP
titration is the minimum acceptable duration. If
an adequate titration is not obtained, a repeat
PSG titration is indicated.
Before the initiation of the PAP titration
• Extensive education about the pathophysiology
of OSA, the consequences of untreated OSA, as
well as PAP therapy should be given to the
patient.
• Videotapes and supplemental reading are
additional tools that may help patient adherence.
• Ensure optimal mask fit in order to improve
comfort and reduce the potential for mask leak.
In some cases, a chin strap or a full-face mask
may be required to eliminate mouth breathing,
which should be assessed once the titration
study has begun .
The endpoint of the titration
• When determining a titration algorithm, it is essential to
understand that elimination of apneas, hypopneas, and
oxygen desaturations is the first objective, but not the
endpoint of the titration.
• The endpoint of the titration should be elimination of
snoring and respiratory-related arousals in all positions
and all stages of sleep.
• Persistent inspiratory airflow limitation is evidenced by
a flattened airflow pressure tracing and can best be
demonstrated with titrations that are performed with
nasal pressure-flow transducers, as opposed to
thermistors or other indirect measures of airflow .
Assessing increased respiratory effort due
to flow limitation
• Although esophageal pressure monitoring is the most
accurate means of assessing increased respiratory
effort due to flow limitation, this modality is often poorly
tolerated which may in turn limitits routine use in CPAP
titration studies.
• When inspiratory airflow limitation is associated with
spontaneous arousals, it is likely due to upper airway
resistance syndrome (UARS) and a further increase in
airway pressure is indicated .
• Careful monitoring of esophageal pressures, and/or
CPAP airflow signals, generally demonstrates continued
evidence of airflow resistance until CPAP pressures
have been increased to 2 cm H2O, on average, above
that needed to eliminate apneas and hypopneas .
Upward then downward titration
• Patients undergoing CPAP titration may display
increased pressure requirements during titration from
lower CPAP pressures upward, as compared to
pressures required during downward titration from
higher pressures .
• It is appropriate during a titration study to titrate
pressures upward until elimination of respiratory events
has been achieved and a normal airflow pattern is
attained; and then titrate downward to the return of
obstructive events.
• This method is of particular use in patients who have
difficulty tolerating PAP therapy due to high pressure
requirements.
Optimal pressure
• When performing a titration, it is important to note sleep
stage and body position once optimal pressure is
assumed as evidence that suggests that higher
pressure requirements may be needed in the supine
position and in REM sleep .
• Once an optimal pressure has been attained, in addition
to resolution of sleep related breathing events, sleep
continuity should theoretically improve, with a decrease
in the number of spontaneous arousals and arousals
associated with respiratory events. Commonly, slowwave sleep rebound or REM sleep rebound will be seen
with improved sleep continuity and this finding can be
used as an indication that an effective pressure level is
imminent .
Emergence of central apneas
• It has been shown that increased tidal volumes can
induce central apneas in the setting of normocapnia due
to neurochemical inhibition and possibly, baroreceptor
activity .
• This finding has led to the practice of decreasing CPAP
pressures when the emergence of central apneas is
witnessed during an upward titration.
• It is important to continue to explore upward pressures
with the appearance of central apneas, as there are
several mechanisms that have been shown to elicit
central apneas, including upper airway obstruction,
which may be indicative of sub-therapeutic pressures.
Bilevel mode of delivery of breath
• It has been shown that lower expiratory pressures are
required to maintain airway patency than with
inspiration .
• The efficacy of using bilevel ventilation as a standard
treatment modality in all patients with OSA is
questionable; however, clinicians tend to consider
unacceptably high CPAP pressures, as deemed by
intolerance of the pressure by the patient during the
study, as an indication to change to bilevel mode of
ventilation.
• Clinicians generally feel that patients with lung disease,
chest-wall disease, and/or neuromuscular disease may
be most appropriate for bilevel mode of delivery of
breath.
Standardized titration methods
• While CPAP therapy has been the standard of care for
many years, there is a surprising lack of data validating
standardized titration methods. In particular, details on
the transition from CPAP therapy to bilevel therapy are
lacking.
• In patients with OSA intolerant of CPAP, there exist
primarily three different techniques employed:
(i) an inspiratory pressure is chosen equal to the CPAP
pressure where obstructive events were eliminated;
(ii) an expiratory pressure is chosen equal to the CPAP
pressure where obstructive events were eliminated;
(iii) bilevel is initiated from a low starting pressure,
beginning with baseline pressure settings and titrating
upwards.
Standardized titration methods
• Regardless of the technique followed, it is
generally thought that a 4 cm H2O difference
should be preserved in order to maintain airway
patency during expiration.
• Commonly, expiratory pressure increases are
performed in the setting of persistent or
reappearing apneas, while inspiratory pressure
increases are made in the setting of snoring,
flow limitation, or hypopneas, maintaining a 4
cm difference between the two.
Standardized titration methods
• The use of BPAP in patients with OHS should be
initiated in a similar fashion; however, if
hypoxemia persists after resolution of
respiratory events, in particular during REM
sleep, the addition of supplemental oxygen in
these patients is appropriate.
• Special consideration is needed when using
BPAP in patients with central sleep apnea (CSA)
not responsive to CPAP, especially patients
with CSA-CSR in the absence of OSA. These
patients will often need a “timed mode” of
inspiration as the bilevel unit will not be
triggered due to lack of inspiratory effort.
Standardized titration methods
• Adaptive servo ventilation ( ASV) has been
developed in the hope of creating a more
effective means of treating CSA-CSR and
improving adherence.
• ASV ventilation provides positive expiratory
airway pressure and inspiratory pressure
support that is servo-controlled based on the
detection of CSR, with a backup respiratory
rate.
• Initial studies show great promise for this
device as means of effectively controlling CSACSR .
Standardized titration methods
• The use of “daytime” titrations is another
method that has been proposed to derive
optimal pressure settings.
• Limited efficacy and adherence data call this
technique into question though initial
nonrandomized cohort studies do show some
comparable results to overnight titrations .
Factors contributing to the therapeutic
efficacy of PAP therapy over time
• In the absence of significant clinical changes, a
pressure level chosen during a single night’s titration is
generally effective on longitudinal nights . However,
CPAP non adherence, coexisting sleep fragmenting
disorders, significant weight gain and chronic medical
or psychiatric conditions and nasal congestion are all
factors that can alter the efficacy of CPAP therapy.If a
patient who initially responded to treatment begins to
complain of recurrent symptoms, consider these
contributing factors as a potential cause.
• It is imperative for the clinician to consider all causes of
“residual hypersomnolence” in the treated OSA patient,
and the most common cause of sleepiness is
insufficient sleep.
PERIOPERATIVE MANAGEMENT
• Patients undergoing any surgical procedure are
susceptible to postoperative complications due to
respiratory compromise.
• Patients with OSA are at obvious risk for a
postoperative complication due to the perioperative use
of narcotics and benzodiazepines, which are known to
blunt the respiratory response to hypercapnea and to
hypoxia as well as exacerbate upper airway obstruction
• Unfortunately, many patients undergoing surgical
procedures are not appropriately screened for OSA and
may be put at risk for postoperative complications, in
particular patients having outpatient surgical
procedures who are sent home to a completely
unmonitored environment.
PERIOPERATIVE MANAGEMENT
• The American Society of Anesthesiologists (ASA) have
recognized the risk of postoperative complications
associated with patients who have undiagnosed OSA and
thereby published practice guidelines outlining
recommendations of how to identify and treat patients at
risk.
• The ASA practice parameters suggest that preoperatively,
anesthesiologists should work with surgeons to develop a
protocol whereby patients in whom the possibility of OSA is
suspected on clinical grounds are evaluated long enough
before the day of surgery to allow preparation of a
perioperative management plan.
• The recommendations go on to include preoperative
preparation where preoperative initiation of CPAP should
be considered, particularly if OSA is severe.
PERIOPERATIVE MANAGEMENT
• Because of their propensity for airway collapse and sleep
deprivation, patients with OSA are especially susceptible to
the respiratory depressant and airway effects of sedatives
,narcotics, and inhaled anesthetics.
• In selecting intraoperative medications, the ASA practice
parameters suggest that the potential for postoperative
respiratory compromise should be considered.
• Regional analgesic (pain relief) techniques should be
considered to reduce or eliminate the requirement for
systemic opioids (narcotics) in patients at increased
perioperative risk from OSA.
• Before patients at increased perioperative risk from OSA are
scheduled for surgery, a determination should be made
regarding whether a given surgical procedure is most
appropriately performed on an inpatient or outpatient basis.
MONITORING
Monitoring during Positive Pressure Titration
• Most positive-pressure devices used in the sleep
disorders center provide several analog or digital
outputs that can be recorded .
• The total flow delivered by the machine is measured by
an accurate flow sensor in the PAP device.
• Use of a thermal device under the mask to monitor flow
is not recommended.
• The total flow is then divided by the device into two
components that are supplied for monitoring:
(1) the PAP flow (also known as CPAP flow, C flow, or
machine flow), which varies with inspiration and
expiration, and
(2) the leak (bias flow), which is a fairly constant portion
due to system leak .
Monitoring during Positive Pressure Titration
• Total flow = PAP flow + Leak
• Total flow increases with pressure but is separated into a
variable component (CPAP flow) and a more constant
component (leak).
• The leak includes intentional (mask orifice) and
unintentional leak.
Leak = Intentional leak + Unintentional leak
• On higher CPAP, the total flow increases as the
intentional flow increases (even if unintentional leak does
not increase).
• All CPAP mask interfaces have a built-in orifice system
consisting of small holes to provide an intentional leak
that washes out exhaled CO2 from the mask and prevents
rebreathing.
Monitoring during Positive Pressure Titration
• This intentional leak increases with the amount of pressure
and varies between different masks .
• The unintentional leak is due to mask or mouth leak (in the
case of a nasal mask).
• Leak is seen by the machine as bias or constant baseline
inspiratory flow onto which the variations in patient flow is
superimposed.
• The leak signal provided by some devices is the total leak
whereas others provide an estimate of unintentional leak by
subtracting the expected leak given the mask and pressure
(mask type must be specified).
• Absolute values are less useful than relative increases in
leak.
Intentional leak increases with pressure and depends on
the mask type (A, B, or C). Information is available with
each mask.
Monitoring during Positive Pressure Titration
• The PAP flow signal provides not only an estimate of the
magnitude of flow but also information from the
inspiratory flow contour.
• High upper airway resistance is manifested by a flattened
profile .The normal profile is a rounded one.
• Snoring can be detected by a snoring sensor placed on
the neck or from pressure vibrations in mask pressure.
• Nearly all sleep center PAP units will also provide a signal
of the “machine pressure.” This is the pressure at the
machine outlet and can differ slightly from the set
pressure (value entered by technologist).
• Mask pressure may be somewhat lower during inhalation
and sometimes slightly higher during exhalation.
• Mask pressure can also be directly measured by
connecting the mask to a pressure transducer.
A drop in CPAP; arrow , results in change of flow signal (becoming flattened
consistent with airflow limitation )and increased pressure gradient across the
upper airway (increased resistance).
Flattening in the CPAP flow signal (arrow) suggests high upper airway resistance,
and this is consistent with the appearance of snoring. After only 1 cm H2O increase
in pressure, the CPAP flow signal is now round and the snoring has stopped.
Monitoring during Positive Pressure Titration
• Recording of the leak signal is useful for the
physician reviewing a PAP titration.
• The trend in the leak is more useful than the
absolute number. If the patient has not moved
and leak suddenly increases, this could be a
hint that mouth leak is occurring (assuming the
patient is wearing a nasal mask).
• Sometimes, an increase in leak can occur with
the onset of REM sleep. Relaxation in the facial
musculature can sometimes produce mask or
mouth leaks.
The patient was wearing a nasal mask and chin strap. At the transition to stage R, a
large increase in leak was noted . Note that the increase in leak signal lags behind
the obvious change in flow that occurs a few seconds earlier.
If the flow
Monitoring during Positive Pressure Titration
• If the flow signal becomes truncated during expiration,
this means that part or all of flow during exhalation is
not sensed by the machine flow sensor (no flow
returning to the hose / device system) consistent with
an expiratory leak from either the mask or the mouth.
• If the patient is wearing a nasal mask (which has not
moved), the sudden appearance of truncated expiratory
flow (often associated with vibration in the snoring
sensor) is suggestive of expiratory mouth leak .
• The technician does not necessarily have to intervene
unless mouth leak is arousing the patient or preventing
PAP from maintaining a patent airway. If mouth leak is a
problem, either using a chin strap or an oro-nasal mask
or lowering the pressure could be considered.
A change in expiratory flow combined with expiratory snoring is
suggestive of an expiratory leak. Compare the truncated
expiratory flow in epoch 602 with the normal expiratory flow in
epoch 600. This is due to expiratory mask or mouth leak (if a
nasal mask is being used).
Additional Monitoring for NPPV Titration
• For NPPV titration, it is useful to record the tidal volume
signal from the PAP device that is derived from integration
of the flow signal .
• Tidal volume depends both on flow and inspiratory time.
Therefore, monitoring the flow signal alone may not
provide an accurate estimate of ventilation.
Patient is breathing on BPAP spontaneous timed (ST) mode with a
backup rate of 12 breaths/min. Breaths A and C are patient initiated
and breaths B and D are machine-cycled breaths. The tidal volume
differs between breaths A , B and C,D due to a different IPAP time.
Additional Monitoring for NPPV Titration
• Some sleep centers that perform NPPV in
patients with neuromuscular disorders also
record an intercostals electromyogram (EMG)
or surface diaphragmatic EMG with techniques
similar to those for leg EMG.
• If the signal decreases, tidal volume increases
and respiratory rate decreases; these changes
suggest that adequate respiratory muscle rest is
being delivered by the current level of PS.
When the level of pressure support was increased,
there was a decrease in the respiratory rate and in
the intercostal electromyogram (EMG)
Additional Monitoring for NPPV Titration
• Some sleep centers record either the end-tidal partial
carbon dioxide pressure (PETCO2) or trans-cutaneous
carbon dioxide pressure (TcPCO2) .
• A PETCO2 tracing should show a plateau.
• The exhaled gas sampled for the PETCO2 measurement
can be diluted by NPPV flow. A common method is to use a
small nasal cannula under the mask that suctions exhaled
air at the nares before it can be diluted. A downside is that
this can cause problems with the mask seal.
• Another option is to record is the TcPCO2. These surrogate
measures of PCO2 are useful only if calibrated and
validated (ideally with an arterial or capillary blood gas).
The CO2 tracing is delayed relative to exhaled airflow in
the side stream method
• .
Note the simultaneous increase in transcutaneous PCO2 and the
decrease in SpO2 during episodes of rapid eye movement (REM) sleep.
ACCURACY OF PETCO2 AND TcPCO2
• The measurement of PETCO2 and TcPCO2 was not found
to be accurate for determining changes in PaCO2 during
sleep.
• PETCO2 was especially inaccurate during simultaneous
administration of supplemental oxygen or during positive
airway pressure treatment. Of note, exhaled gas was
sampled from a mask rather than using a nasal cannula.
• PETCO2 or TcPCO2 may be acceptable if validated and
calibrated.
• In the pediatric rules, it states that “acceptable methods
for assessing alveolar hypoventilation are either
transcutaneous or end-tidal PCO2 monitoring.”
• Of course, the goal standard to validate the accuracy of
their measurements is a simultaneous ABG measurement.
Titration for CPAP Therapy
Set mode to CPAP
Initial pressure: 4–5 cm H2O
EPR™ and Easy-Breathe (CPAP and AutoSet™)
• EPR is designed to maintain optimal treatment for the
patient during inhalation and reduce the delivered mask
pressure during exhalation in the CPAP or AutoSet
mode.
• The desired result of EPR is to decrease the pressure
the patient must breathe out against, making the overall
therapy more comfortable.
• EPR LEVEL of OFF, 1, 2, or 3 cm H2O can be selected.
• In CPAP mode, the EPR INHALE can be set to medium
or fast.
• The delivered pressure will not drop below a minimum
pressure of 4 cm H2O, regardless of the settings.
Pressure-intolerant patients
• If the patient awakens and complains of
excessive pressure, pressure should be
lowered. If this does not work, use of flexible
PAP or a switch from CPAP to BPAP may be
tried.
• When switching from CPAP to BPAP, one
approach is to use IPAP 2 cm H2O higher than
CPAP and EPAP 2 cm H2O lower.
• Another approach is to use EPAP = CPAP, and
IPAP = EPAP + 4 cm H2O and titrate pressure
upward if needed.
Pressure-intolerant patients
• In pressure-intolerant patients, sleep in the lateral
position or with the head elevated can be tried to reduce
the required level of pressure.
• If mouth leak is a problem, a chin strap can be tried
followed by an oro-nasal mask.
• If there is excessive mask leak, a readjustment of the
mask, change in mask size, or change in mask type is
indicated. Over tightening of the mask straps is strongly
discouraged.
• In patients with allergic rhinitis or nasal congestion, use
of heated humidification from the start of the study is
suggested.
PAP and Supplemental Oxygen
• Some patients will exhibit significant arterial oxygen
desaturation despite adequate airflow, especially during
REM sleep . Persistent hypoxemia in these conditions
may be due to hypoventilation or ventilation-perfusion
mismatch (often due to chronic lung disease).
• In some studies of titration in patients with OHS, a
substantial number of patients required the addition of
supplemental oxygen.
• If the awake supine patient has an SaO2 of 88% or lower
or is already on supplemental oxygen to maintain an
acceptable awake SaO2, the addition of supplemental
oxygen will definitely be needed.
• Before adding supplemental oxygen, one can attempt to
adjust the PAP pressure settings to prevent the need for
this additional treatment.
PAP and Supplemental Oxygen
• If the patient is requiring high oxygen flows, optimizing
PAP may allow reduction in the required oxygen flow
rate. First, an increase in CPAP can be tried to eliminate
unrecognized high upper airway resistance. If this is not
successful or not tolerated, CPAP can be changed to
BPAP .
• If the patient is already on BPAP, the level of PS can be
increased.
• If these interventions do not increase the SaO2 to an
acceptable level or if higher pressure is not tolerated,
supplemental oxygen can be added to PAP. with a goal
of attaining an acceptable SaO2 (88–94%).
• Most clinicians would use a target 92% to 94% to allow
for variability and a margin of safety.
PAP and Supplemental Oxygen
• It is important to recognize that the effective oxygen
concentration will depend on both the supplemental
oxygen flow (L/min) and the machine flow.
• Increases in machine flow associated with higher
pressure or mask /mouth leak can dilute a given flow of
supplemental oxygen. For example, if a patient with
chronic lung disease requires supplemental oxygen at 2
L/min to maintain an SaO2 of 94% while awake without
CPAP, on CPAP the required supplemental oxygen flow
will likely be much higher (assuming the same fractional
concentration of oxygen on CPAP treatment is still
required).
Approximate change in effective fractional concentration
of oxygen in inspired gas (FiO2) with supplemental oxygen
and various CPAP levels in a model system
Complex Sleep
Apnea
Complex Sleep Apnea
• Complex Sleep Apnea (Comp SA) is defined as a form of
central apnea specifically identified by the persistence
or emergence of central apneas or hypopneas upon
exposure to CPAP or a BPAP without a backup rate
when obstructive events have disappeared.
• Patient with CompSA have predominantly obstructive or
mixed apneas during the diagnostic sleep study (or
diagnostic portion of a split study) occurring at 5/hr or
greater.
• The CMS definition of Comp SA requires that
1- Greater than 50% of the residual respiratory events on
PAP are central apneas or central hypopneas,
2- The central AHI is 5/hr or greater, and
3- The total AHI is 5 or greater .
Complex Sleep Apnea
• Patients with a combination of OSA and Chyne- Stokes
breathing (CSB)may manifest CSB-central apneas when
CPAP eliminates obstructive events. These patients
meet the definition of Comp SA.
• Patients taking potent opiates develop central apneas
on CPAP (treatment emergent central apneas) or central
apneas persist on CPAP.
• Other patients may manifest CompSA without an
obvious cause (idiopathic CompSA).
• Patients with Cheyne-Stokes central apnea or idiopathic
CompSA tend to have high ventilatory drives or
difficulty maintaining sleep. Central apnea occurs
because the PaCO2 drops below the apneic threshold.
The approach to CompSA and PAP titration
protocol for handling central apneas varies
between sleep centers.
• One approach is to increase CPAP only until the
obstructive apneas and hypopneas are eliminated.
CPAP is increased further only if RERAs are believed to
be causing central apneas (after the arousals).
• Many patients will stabilize if they enter stage N3 sleep
(i.e., patience rather than increasing the CPAP).
• A small reduction in pressure to one not associated with
central apneas can also be tried.
• Some patients will also improve in the lateral sleeping
position.
NB :Switching from CPAP to BPAP without a backup rate
is NOT indicated and may actually contribute to
ventilatory instability.
The approach to CompSA and PAP titration
protocol for handling central apneas varies
between sleep centers.
• Many patients with Comp SA when treated with
CPAP on a chronic basis will have a resolution
of the central apneas.
• Others with CSB or narcotics as a cause for
ventilatory instability may continue to have
frequent central events on chronic CPAP
treatment. These patients should undergo
another PAP titration with ASV or BPAP with a
backup rate.
• It is better to utilize an entire night to perform an
ASV titration
ASV Titration Protocol
• For the Adapt SV, EPAP = 4 cm H2O, PS max of 10 cm H2O
or greater , PS min of 3 cm H2O. EPAP should be increased
slowly to allow the patency of upper airway.
• For the BiPAP auto SV advanced, recommended settings
are EPAP min = 4 cm H2O, EPAP max = 15 cm H2O, PS min
= 0 cm H2O, PS max = 20 cm H2O, Max pressure = 25 cm
H2O, rate = auto. If it is known that CPAP greater than 10
cm H2O is needed to prevent obstructive apnea, EPAP min
of 6 to 8 cm H2O could be tried.
• For those with a component of hypoventilation (narcotics),
PS min of 4 cm H2O could be used.
• Most insurance providers have definite criteria for
reimbursement for ASV or BPAP with a backup rate
Usually more than 50% of the events on CPAP must be
either central apneas or central hypopneas.
ASV Titration Protocol
• Servo-ventilation made by different
manufacturers can successfully detect and treat
central apneas .
• During servo-ventilation, the expiratory positive
airway pressure is set at a level to treat
obstructive apneas and obstructive hypopneas.
• Combining APAP and servo-ventilation, with
APAP determining the EPAP level automatically,
whereas the servo-ventilation controlling
periodic breathing and central apneas has been
recently reported to be effective in ameliorating
SRBD .
SomnoVent CR
Respironics autoSV
ResMed VPAP Adapt SV
Score a hypopnea as obstructive if ANY of the
following criteria are met:
1. Snoring during the event
2. Increased inspiratory flattening of the nasal pressure or
PAP device flow signal compared to baseline breathing
3. Associated thoracoabdominal paradox occurs during
the event but not during pre-event breathing.
Score a hypopnea as central if NONE of the following
criteria are met:
1. Snoring during the event
2. Increased inspiratory flattening of the nasal pressure or
PAP device flow signal compared to baseline breathing
3. Associated thoraco-abdominal paradox occurs during
the event but not during pre-event breathing.
Adequacy of PAP Titration
1) An optimal titration is one that reduces the AHI to less
than 5/hr for at least 15 minutes and should include
supine REM sleep at the final pressure without
repeated arousals.
2) A good titration results in an AHI < 10/hr or at least a
50% reduction in the AHI if the baseline AHI is less
than 15/hr. A good titration should include supine REM
sleep at the selected pressure that is not continually
interrupted by arousals.
3) An adequate titration is one that does not reduce the
AHI < 10/hr but does reduce the AHI by 75% from
baseline, or one in which criteria for optimal or good
titration is met with the exception that supine REM
sleep did not occur at the selected pressure.
Adequacy of PAP Titration
• 4) An unacceptable titration does not meet any
of these criteria. A repeat titration should be
ordered.
• In optimal, good, and acceptable titrations, the
SaO2 should remain above 90% at the treatment
pressure selected for chronic use.
• If a titration shows borderline oxygenation, it is
then prudent to check nocturnal oximetry while
the patient uses PAP at home.
A portion of overnight oximeter of patient with both
snoring and COPD. The baseline is reduced during sleep
but the saw-tooth patteren is suggestive of obstructive
sleep apnea A = Period of REM sleep.
ALTERNATIVE
METHODS OF
STARTING PAP
TREATMENT
ALTERNATIVE METHODS OF STARTING
PAP TREATMENT
• The titration alternatives can be used for patients
who are unwilling or unable to have a standard
PSG titration. These alternatives include
• Treating the patient with an APAP device (titration
not needed)
• Performing autotitration at home for several days to a
week (at least 3 days optimum) with subsequent
CPAP treatment based on the results, and
• Starting PAP treatment based on a prediction
equation with subsequent adjustment based on
symptoms, machine readings, and nocturnal
oximetry.
ALTERNATIVE METHODS OF STARTING
PAP TREATMENT
• The prediction equation can provide an empirical
treatment level or a reasonable starting point for
a PAP titration.
• The optimal treatment pressure may differ
substantially from the predicted pressure.
• The formula considerably underestimates the
required pressure, especially in men.
• CPAP predicted
=0.16XBMI +0.13 X NC + 0.04 XAHI – 5.12
where BMI = body mass index and
NC = neck circumference in centimeters.
ALTERNATIVE METHODS OF STARTING
PAP TREATMENT
• Most PAP devices provide an estimate of the residual
AHI. Some devices also separate apneas into “clear
airway apneas” and “obstructive apneas.” .
• Comparing standard PSG titration, autotitration for one
night followed by CPAP treatment based on the results,
and CPAP based on a prediction formula with
subsequent adjustments based on symptoms and at the
end of a 12-week period, all patients were studied on
their current CPAP pressure. All three methods resulted
in equivalent CPAP adherence, control of the AHI, and
improvement in subjective sleepiness.
Patient Selection for Alternative Titrations
• Patients with a number of conditions are not suitable for
APAP titration or treatment. These include
1-patients who require or are likely to require
supplemental oxygen (low baseline SaO2)
2-patients with hypoventilation
3-patients likely to have central apneas (narcotics,
congestive heart failure), and
4-patients who may require very high pressures.
• Patients with severe pressure intolerance or moderate
to severe COPD who may require BPAP should also
undergo a PSG titration if possible.
Technique of Autotitration
• The patient is educated about OSA and PAP treatment
and has mask fitting and instructions on use of an APAP
device. It is often useful for the patient to take a brief
practice nap during which she or he applies the
interface, activates the APAP device, and “naps” for
about 15 or 20 minutes.
• The patient then sleeps on the APAP device at home for
several nights. Usually, the pressure limits of the device
are set from 4 to 20 cm H2O.
• In large patients likely to require high CPAP, starting
with pressure of 4 cm H2O may be uncomfortable, so a
higher low-pressure limit is chosen (8–10 cm H2O).
• For the pressure-intolerant patient, a lower upper limit of
pressure can be chosen.
• A telephone hotline is available for interventions .
Technique of Autotitration
• The device is then returned and the information
transferred to a computer.
• The quality of the autotitration can be noted including
amount of use (adherence), residual AHI, and amount of
leak.
• Either the 95th percentile pressure or the 90th percentile
pressure (depending on device) is chosen for chronic
PAP treatment.
• If the APAP titration is suboptimal owing to poor
adherence, high leak, or high residual AHI, another
attempt can be made using a different mask, heated
humidfication, or other interventions.
• If two attempts at an APAP titration are unsuccessful,
the patient can be referred for a PSG titration.
Follow-up of Patients on PAP Treatment
• Because the pattern of adherence is set early,
obtaining a download within the first week and
having a face-to-face visit at or soon after 4
weeks of use is recommended.
• CMS rules require at least 1 month of 70% of
nights with greater than 4 hours of use. This
month of adherence must occur within the first
3 months of CPAP use for treatment to continue
to be reimbursed.
• Most PAP machines give information on leak
and residual AHI. Some can give detailed
information about residual events including
clear airway events (central apneas).
Follow-up of Patients on PAP Treatment
• High proportion of patients “well treated” with CPAP
who had elevated AHI values on their current treatment
pressures.
• A high residual AHI found on CPAP machine download
would suggest that
1- the current pressure was inadequate (unless the events
were central apneas) or
2- that an inadequate mask seal significantly reduced the
delivered pressure.
• Some CPAP and APAP devices present the residual AHI,
hypopnea index (HI), and a snoring index. If the residual
apnea index exceeds the HI, this is a clue that central
apnea may be present.
Follow-up of Patients on PAP Treatment
• Recently, CPAP and APAP devices can separate
apneas into obstructive apneas and “clear
airway apneas.”
• A high residual AHI in a patient with congestive
heart failure or potent narcotic use would
suggest the possibility of central apneas.
• High leak would suggest need for better
interface fit. The interface could be adjusted or
changed to a different size or interface type.
• If extreme dryness is present and a reasonable
humidity must be prescribed.
CA = clear airway apnea; FL = flow limitation; H = hypopnea; OA =
obstructive airway apnea; PB = periodic breathing; RE = respiratory
effort–related arousal; VS = vibratory snore.
NPPV Titration and Treatment
• The titration of NPPV focuses on providing ventilator
support in addition to maintaining an open airway.
• Patients with neuromuscular disorders, thoracic cage
disorders, or disorders of inadequate ventilatory control
may not be obese and may not require as high an EPAP
as patients with OSA or OHS.
• IPAP and EPAP are titrated as per the protocol
discussed previously to eliminate obstructive events.
However, the goal is to provide adequate PS without
using excessive pressure. Therefore, BPAP of 16/4 or
20/5 cm H2O might be typical pressures.
NPPV Titration and Treatment
• The ST mode is used for treatment of all patients with
central ventilatory control disorders and is also
recommended for patients with neuromuscular
disorders and thoracic cage disorders.
• These patients may not reliably cycle the BPAP device
from EPAP to IPAP.
• The ST mode is also needed if central apneas are noted
during the NPPV titration.
• The backup rate is usually set 1 to 2 breaths below the
sleeping spontaneous breathing rate (8–10 breaths/min
minimum).
• The Ti is chosen between 30% and 40% of the cycle
time, this is also known as the % IPAP time.
NPPV Titration and Treatment
• In general, patients with airflow obstruction
(COPD) are best treated with 30% %IPAP time
and those with restrictive disorders may do
better with 40% %IPAP time.
• One manufacturer recommends using 1.5
seconds as the default inspiratory time for
BPAP-ST.
• The rise time is the time from start of the IPAP
cycle until IPAP pressure is reached. It is
typically around 200 msec (200–600 msec) but
can be varied for patient comfort.
Rise time
Goals of NPPV Titration and Treatment
1- Improving sleep quality and preventing
nocturnal dyspnea,
2- Preventing nocturnal hypoventilation (or
worsening of hypoventilation during sleep if
daytime hypoventilation is present), and
3- Providing respiratory muscle rest.
• For patients with daytime hypoventilation, use
of NPPV can improve the quality of life and
delay or prevent the progression of respiratory
failure .
Goals of NPPV Titration and Treatment
• The nocturnal PaCO2 goal is a value equal to or less
than the daytime PaCO2. However, sufficient PS may not
be tolerated initially.
• NPPV can be started on an outpatient basis at low
pressure (BPAP 8/4) and increased as tolerated based
on patient symptoms and oximetry, daytime PETCO2
measurements, or daytime arterial blood gas
measurements.
• NPPV PSG titration is recommended and allows a
treatment to be chosen (IPAP, EPAP, backup rate) that
will eliminate obstructive apnea/hypopnea and deliver
optimal PS. Some patients will also require the addition
of supplemental oxygen.
Goals of NPPV Titration and Treatment
• Close follow-up is needed because the given
level of pressure support may prove inadequate
if respiratory muscles weaken.
• Titration using VT-BPAP (BiPAP AVAPS) is
performed to determine an effective EPAP. The
ST mode is commonly used. The device will
automatically adjust PS to provide a desired
tidal volume.
• If pressure intolerance is a problem, a lower
tidal volume target with a higher respiratory rate
(spontaneous or machine-triggered) may be
better tolerated.
AVAPS averages Vt and changes PS value
gradually. This occurs over several minutes.
The rate of change is slow , so the patient is not
aware of breath to breath change.