Transcript CPAP and BPAP Titration

CPAP and BPAP
Titration
BY
AHMAD YOUNES
PROFESSOR OF THORACIC MEDICINE
Mansoura faculty of medicine
Titration of Positive airway pressure
• Positive airway pressure (PAP) devices such as
CPAP and BPAP are used to treat SDB.
• At an optimal pressure, PAP devices eliminate
SDB events without creating pressure-related side
effects.
• The gold standard method for identifying the
optimal pressure is attended overnight laboratory
based polysomnography during which a sleep
technologist manually titrates the PAP devices to
eliminate SDB events, such as apneas, RERAs,
and snoring
• Using a nasal pressure transducer or a thermistor
during the titration portion of the polysomnography may
not be feasible because of problems obtaining a good
seal with the mask interfaces.
• During a titration study, recordings from the airflow
signal generated by the PAP device, or estimating the
airflow through measuring the pressure difference
between the mask and the outlet machine using a
transducer, are acceptable methods to detect apneas,
hypopneas, and RERAs.
• Titration protocols to identify the optimal pressure for
PAP devices to treat SDB vary widely among sleep
centers. Therefore, it is very likely that the same patient
undergoing a titration study at different accredited
centers may end up with different optimal pressures.
SPLIT-NIGHT TITRATION
• The criteria that is typically used is an AHI of 40 or more
per hour with a minimum of 120 minutes of sleep, or an
AHI of 20 to 40 per hour accompanied by significant
oxygen de-saturation .
• The Center for Medicare & Medicaid services (CMS)
requires either :(1) the documentation of an AHI of 15 or more per hour
with a minimum of 30 events , or
(2) an AHI of 5 to 14 per hour with a minimum of 10 events,
along with documentation of one of the following:
excessive sleepiness, impaired cognition, mood
disorder, insomnia, hypertension, ischemic heart
disease, or history of stroke.
• The optimal pressure for PAP devices to treat SDB is the
effective pressure that eliminates SDB events without
creating any untoward pressure-related side effects for
the patient.
• Pressures lower than the optimal pressure, apart from
inadequately treating the SDB, may also result in mouth
breathing and claustrophobic symptoms.
• Pressures exceeding the optimal pressure may lead to air
leaks, mouth breathing, worsening of nasal congestion,
and rhinorrhea ; exacerbate central apneas; and of
course lead to difficulty tolerating the PAP, resulting in
decreased overall adherence.
• The optimal pressure should be effective in all sleep
positions and sleep stages.
GOALS OF PAP TITRATION
• The goal of PAP titration is to identify the optimal
pressure that
1- eliminates SDB events (apneas, hypopneas, RERAs,
oxygen desaturation, and snoring),
2- restores normal respiratory patterns , and
3- improves the patient’s quality of sleep.
• The optimal pressure from PAP that accomplishes all this
should be adequate during all stages of sleep and in all
sleep positions (particularly supine position), because the
severity of OSA is commonly worse during sleep in the
supine position, and during REM sleep, whereas the
severity of CSA might be worse during supine and nonREM sleep.
• Optimal titration is obtained when the AHI is < 5 per hour
for at least 15 minutes and includes supine REM sleep at the
optimal pressure.
• Good titration reduces the AHI to < 10 per hour and
includes supine REM sleep at the selected pressure on
the PAP device.
• Adequate titration is obtained when the AHI cannot be
reduced to < 10 per hour, but is reduced by 75% from
baseline, or when the titration grading of optimal and
good are obtained even though supine REM sleep did not
occur.
• An unacceptable titration occurs if any one of the above
grades are not met, at which time a repeat titration is
necessary.
• Repeat full titration is also needed if only adequate
titration was obtained, especially if it was part of a splitnight protocol.
PREPARATION FOR PAP TITRATION
•
•
•
The AASM practice parameters recommend that all
eligible patients receive adequate PAP education, handson
demonstration,
careful
mask
fitting,
and
acclimatization to the PAP device before titration.
PAP education before titration could be in the form of a
video describing sleep apnea, consequences of
untreated sleep apnea, rationale for the use of PAP, the
process involved during the diagnostic and PAP titration
polysomnogram ,and side effects related to the PAP and
mask interfaces.
Showing and explaining the device along with its parts
and equipment ,and having the patient try on the mask
interface to experience the pressure generated by the
device, are all important steps before implementing PAP
titration.
Indications for CPAP
• Most patients with OSA can be effectively treated with
CPAP, which serves as a passive pneumatic splint to keep
the upper airway from collapsing during sleep. It also
tends to increase lung volumes and exerts tracheal
traction (tracheal tug mechanism) to prevent collapsibility
of the upper airway.
• The use of CPAP in reducing CSA (particularly in CSA/CSR
and primary CSA) was found in some studies showing
improvement in the left ventricular ejection fraction and
Epworth sleepiness scale Therefore, performing a CPAP
titration for CSA is reasonable to assess for effectiveness
before switching to a different PAP device, such as BPAP
in the spontaneous timed mode (BPAP-ST) or adaptive
servo-ventilators. CPAP may not be effective in treating
CSA caused by opioid use.
CPAP TITRATION
• At the start of CPAP titration, pressure is usually initiated at
4 to 5 cm H2O.
• Some patients may experience insufficient pressure at the
start of titration, even with pressure at 5 cm H2O. In these
cases, the pressure can be increased until the patient is
comfortable and then, once the patient falls asleep, the
pressure is reduced in decrements of 1 cm H2O at 5-minute
intervals until SDB returns or the patient awakens.
• CPAP is then increased incrementally by 1 cm H2O at
intervals of no less than 5 minutes until all SDB events are
eliminated.
• CPAP increments are performed in the presence of at least
two obstructive apneas, or at least three hypopneas, or at
least five RERAs, or at least 3 minutes of loud snoring.
CPAP TITRATION
• The recommended maximum pressure to titrate CPAP is
20 cm H2O, at which time BPAP titration will need to be
considered if SDB events are still occurring.
• Adding supplemental oxygen for sleep-related
hypoxemia or hypoventilation may also need to be
considered.
• If the SDB events are not controlled with CPAP because
of patient complaints of increased pressure side effects
(even at CPAP <20 cm H2O),then adding a humidifier for
nasal congestion or instituting a pressure-relief
mechanism at end expiration, such as with C-flex or
expiration pressure relief, should be considered.
• If SDB events are persistent, one may then need to
proceed with BPAP.
CPAP TITRATION
• The optimal pressure is attained in the supine
position and REM sleep for at least 15 minutes if
possible. If this is not attainable, a repeat titration
study should be considered.
• If the patient is unwilling to undergo or insurance
does not cover another night titration, clinicians
could consider prescribing the best pressure
attained on the titration with a follow-up
overnight oximetry on the optimal CPAP settings.
Some prescribers might advocate an auto-CPAP
in these situations. A follow-up study is usually
required on auto-CPAP to ascertain whether the
SDB is well controlled.
CPAP TITRATION
• The titration protocol using CPAP for CSA/CSR is a bit
different from that for OSA. Titration with CPAP can be
started at 4 to 5 cH2O, and then titrated upwards by 1
cm H2O every 5 minutes until CSA/CSR is eliminated.
• CPAP beyond 10 cm H2O is unlikely to be helpful in
controlling CSA/CSR, although exploring higher
pressures may sometimes help identify the optimal
pressure for treating CSA/CSR.
• Persistent or worsening CSA on CPAP titration will
necessitate BPAP titration. Also, although CPAP can
decrease the AHI to less than 5 per hour in OSA, this
may not occur in CSA/CSR.
Treatment-Emergent CSA
• Some patients may have central apneas that become
apparent after CPAP alleviates OSA during CPAP
titration. This event is commonly referred to as
treatment-emergent CSA, or complex sleep apnea.
• One option is to proceed directly to adaptive servoventilation to address treatment-emergent CSA on CPAP
to treat OSA. This approach may lead to the use of an
expensive device without proven long-term benefits.
• Second approach is to decrease CPAP by 1 to 2 cm H2O
and monitor for 5 to 10 minutes. If central apneas persist,
pressure can be decreased further by 1 to 2 cm H2O as
long as no recurrence of OSA is seen.
Treatment-Emergent CSA
• This downward titration can be attempted until the
centrals disappear as long as OSA does not recur. If
centrals persist or OSA recurs at a lower pressure, then
proceeding with one of the other approaches discussed
is advisable.
• A third approach is to perform an upward titration with
CPAP, not beyond 5 cm H2O above the pressure that
eliminated the OSA. This upward titration may help in
certain cases, especially when the central apneas may
have been misclassified as OSA.
• If central apneas worsen with this upward titration, the
pressure should be lowered to the previous level that
alleviated OSA.
Treatment-Emergent CSA
• BPAP may also be tried.
• Data suggest that these central apneas
dissipate over time with CPAP use. Therefore,
some providers may choose to treat these
patients with CPAP for 2-to 3-months before
repeating another titration study.
• If central apneas persist on CPAP with the
repeat titration study, then treatment should
proceed using other modalities, such as
adaptive servoventilation
BPAP TITRATION
• Upper airway instability in OSA tends to occur during not only the
inspiratory phase but also the expiratory phase; hence the rationale in
using BPAP.
• The EPAP tends to stabilize the upper airway at end expiration so that the
airway is sufficiently patent to permit the patient to trigger delivery of IPAP
by generating low-level inspiratory volume or flow during the subsequent
effort.
• The IPAP level is set to prevent upper-airway closure and partial
obstruction (hypopnea) during the inspiratory phase of breathing.
• Different types of BPAP devices are available, with the most commons
being the conventional spontaneous mode (patients may breathe with
their own frequency, with the BPAP supporting both phases of respiration
based on the pressure settings of IPAP and EPAP) and the backup rate
mode (BPAP-ST mode) guarantees a certain number of pressure cycles (or
breaths) per minute, which changes to the higher pressure (IPAP) if the
patient does not initiate a breath within a specified period. Inspiratory time
must be set on the BPAP-ST machines, which tells the machine the
maximum time allowed for inspiration.
Indications for BPAP Use
• Several studies comparing the effectiveness of BPAP and
CPAP, with and without coexisting respiratory disorders,
showed no differences in the improvement of AHI, ESS,
sleep quality, no differences have been seen in adherence
or comfort level in the treatment of OSA without
coexisting respiratory disorders.
• OSA who have comorbid obesity and daytime
hypercapnia prefer BPAP over CPAP in the treatment of
OSA.
• BPAP still tends to be considered for OSA treatment, even
in patients without comorbid respiratory disorders,
particularly when they are unable to tolerate CPAP
because of a high pressure requirement or have
persistent OSA on CPAP even at a pressure of 20 cm H2O.
Indications for BPAP Use
• The use of BPAP is well defined in patients presenting with
acute respiratory failure related to COPD exacerbation. The
role of BPAP during sleep in patients with stable chronic
COPD and chronic hypercapnic respiratory failure is less
well defined
• Guidelines, BPAP can be considered in the presence of
symptoms such as fatigue, morning headache, or daytime
hypersomnolence, and one of the following:
(1)PaCO2 > 55 mm Hg,
(2) PaCO2 of 50 to 54 mm Hg and nocturnal oxygen
saturation of 88% or less for 5 minutes while receiving
oxygen therapy of >2 L/min), or
(3) PaCO2 of 50 to 54 mm Hg and hospitalization related to
recurrent episodes (>2 in a 12-month period) of
hypercapnic respiratory failure.
Indications for BPAP Use
BPAP coverage in patients with restrictive thoracic disorders are:
1- documentation exists of a progressive neuromuscular disorders or
severe thoracic cage abnormality.
2- either (a) PaCO2 of > 45 mm Hg while the patient is awake and breathing
the usual FIO2 or
(b) sleep oximetry shows an oxygen saturation of 88% of less for at least
5 continuous minutes, performed while the patient is breathing the usual
FIO2, or
(c) for a progressive neuromuscular disorders (only) ,maximal
inspiratory pressure is < 60 cm H2O or forced vital capacity is < 50%
predicted ;and
- COPD does not contribute to the patient’s pulmonary limitation
BPAP in the ST mode is useful to treat patients with CSA
syndromes, specifically primary CSA and CSA/CSR. BPAP-ST can
also be used in CSA caused by opioids.
BPAP titration for OSA
BPAP titration for OSA
• Patients requiring BPAP to treat OSA normally do not require an ST
mode; the S mode is usually sufficient.
• If a patient is switched from CPAP to BPAP, the EPAP is started at
the CPAP level at which the obstructive apneas were eliminated.
Otherwise, the EPAP is started at 4 cm H2O and increased in
increments of 1 cm H2O at intervals no shorter than 5 minutes until
the obstructive apneic events are eliminated.
• The IPAP in all these situations is usually started 4 cm H2O higher
than the EPAP, and titrated upward along with the EPAP in
increments of 1 cm H2O, maintaining the IPAP–EPAP difference at 4
cm H2O until the obstructive apneic events are treated.
• Increases in IPAP and EPAP are performed if at least two
obstructive apneas are observed.
• Once the optimal EPAP is obtained to eliminate the obstructive
apneic events, the IPAP is then increased in increments of 1 cm
H2O every 5 minutes in the presence of at least three hypopneas or
five RERAs, or at least 3 minutes of loud snoring .
BPAP titration for OSA
• The maximum recommended IPAP is 30 cm H2O in adults
because of reports of increased risk for barotrauma when
IPAP exceeds 30 cm H2O.
• The minimum IPAP–EPAP differential is 4 cm H2O and the
maximum IPAP–EPAP differential is 10 cm H2O.
• The AASM task force recommends not adjusting the BPAP
settings in the event of oxygen desaturation-resaturation
as long as they are not associated with any obstructive
events. The members do not recommend exploration by
increasing the IPAP above the optimal pressure that
achieved control of SDB events.
• If a patient develops treatment-emergent central apneas,
1- decreasing the IPAP could be attempted. If this does not
help,
2- changing to the ST mode with backup rate might be
helpful.
BPAP titration for CSA
• Most if not all patients require a BPAP-ST mode rather than an S mode
to treat CSA.
• If CSA worsens with BPAP, changing to adaptive servo-ventilation
should be considered.
• If OSA is mixed with CSA during the diagnostic polysomnogram, the
EPAP is usually started at the CPAP level that eliminated the OSA
events. Otherwise, the EPAP is usually started at 4 cm H2O, with the
IPAP at 4 cm H2O higher than EPAP along with ST backup rate.
• The backup rate is usually started below the patient’s spontaneous
awake breathing rate and then increased slowly after the patient falls
asleep. If central apneic episodes persist, the backup rate is increased
by 1 to 2 breaths every 5 minutes to a maximum of 16 breaths per
minute or until the trigger artifact from the BPAP-ST results in a flow
signal. If there is a trigger artifact from the ST backup rate with very
minimal flow, the IPAP is increased at increments of 1 cm H2O every 5
minutes until the hypopneic events are corrected .
• Once the airflow improves or apneic events are controlled, the ST
backup rate and IPAP are not titrated further. If the patient is
uncomfortable with the increase in respiratory rate, the rate is
decreased slowly to 12 breaths per minute or to a rate that the patient
is comfortable, without necessarily compromising the titration.
BPAP titration for CSA
• In the presence of obstructive apneic events in patients with
CSA, the EPAP is increased by 1 cm H2O every 5 minutes,
maintaining an IPAP–EPAP difference, until the obstructive
apneic events are corrected.
• Subsequent titration of IPAP is based on the presence of
hypopneas and central apneas.
• The authors do not recommend the maximum IPAP to
exceed 20 cm H2O and recommend maintaining the
minimum IPAP–EPAP at 4 cm H2O. Also, increasing the
IPAP-EPAP differential has the potential to worsen CSA by
decreasing PaCO2.
• Every effort should be made to identify the optimal BPAP
settings during supine and non-REM sleep, because CSA
tends to worsen during these situations.
• If CSA events are persistent after the maximum IPAP of 20
cm H2O is reached, other modalities should be considered,
such as adaptive servoventilation to treat CSA.
BPAP titration for COPD
• BPAP is started in the S mode. BPAP use for COPD in the
setting of acute respiratory failure used high inspiratory
pressure in the range of 15 to 20 cm H2O, to help with gas
exchange. Increasing the pressure support increases tidal
breathing, resulting in increased minute ventilation and
improvement in hypercapnia.
• Presence of OSA with apneic episodes should be treated
by adjusting the EPAP to eliminate apneas while
maintaining an IPAP-EPAP difference of 4 cm H2O. EPAP
and IPAP are increased in increments of 1 cm H2O every 5
minutes.
• If OSA is not a concern and no apneic episodes occur, the
EPAP is usually left alone and the IPAP is slowly increased
by increments of 1 cm H2O every 5 minutes to correct
hypopneas and hypoventilation in patients with COPD.
• Maximum IPAP–EPAP difference exceeding 15 cm H2O
may become uncomfortable for patients.
BPAP titration for COPD
• Every effort should be made to assess and titrate BPAP
during REM sleep because patients with COPD are most
vulnerable to hypoventilation during this stage.
• Some may require a backup rate with the ST mode
during REM sleep.
• With the machine triggered breaths, a pressure support
of 4 cm H2O (IPAP-EPAP difference) may not be
sufficient to deliver adequate tidal volume. In these
situations ,the IPAP will need to be increased to deliver
adequate tidal volume.
• Despite obtaining adequate BPAP settings to treat
hypoventilation, occasionally supplemental oxygen is
required (for sleep-related hypoxemia) if oxyhemoglobin
desaturations persist.
• An arterial blood gas is obtained within a few minutes of
waking to assess PaCO2 levels.
BPAP titration for neuromuscular disorders
• BPAP is usually started in the ST mode with a rate at or
near the patient’s spontaneous breathing rate (generally
at least 10–12 breaths per minute) for patients with
neuromuscular disorders.
• If OSA is not a concern, the EPAP is initially set low (4–6
cm H2O) with the IPAP generally 4 cm H2O higher.
• Patients with neuromuscular disorders patients may find
higher EPAP settings to be uncomfortable due to
difficulty exhaling. Therefore the titration of EPAP and
IPAP may need to proceed slowly.
• The EPAP is increased in increments of 1 cm H2O in
intervals no shorter than 15 minutes to eliminate apneic
events.
• Once the optimal EPAP is obtained based on elimination
of apneic episodes at a pressure that is comfortable for
the patient, the IPAP is then adjusted by increments of 1
cm H2O in intervals no shorter than 15 minutes to
eliminate hypopneas and hypoventilation.
BPAP titration for neuromuscular disorders
• In patients with only neuromuscular disorders, it is
unlikely that they will need supplemental oxygen. The
predominant underlying pathophysiology is
hypoventilation during sleep, which normally should be
corrected by BPAP alone.
• Use of supplemental oxygen alone (without BPAP) in
patients with neuromuscular disorders may depress the
drive to breathe.
• Every effort should be made to titrate BPAP during REM
sleep since patients with neuromuscular disorders are
most vulnerable to hypoventilation during this stage.
• The initial requirement for the back up rate occurs during
REM sleep when hypoventilation is the worst resulting in
the patient not triggering the BPAP.
• Obtaining an arterial blood gas within a few minutes of
waking up the following morning of the titration is also
recommended to assess PaCO2 levels.
SUPPLEMENTAL OXYGEN TITRATION
• If the patient’s awake supine baseline oxyhemoglobin
saturation is less than 88%, supplemental oxygen is
usually initiated at 1 L/min at the start of the PAP titration
and titrated upward by 1 L/min at intervals no shorter
than 15 minutes.
• Supplemental oxygen should be started during the
titration study if the patient’s oxyhemoglobin saturation
is less 88% for 5 or more minutes in the absence of OSA
events.
• Supplemental oxygen is titrated up at a rate of 1 L/min at
intervals no shorter than 15 minutes to maintain
oxyhemoglobin saturation of more than 88%.
SUPPLEMENTAL OXYGEN TITRATION
• Patients who have persistent sleep-related hypoxemia or
hypoventilation that is not effectively treated with a PAP
device will need supplemental oxygen to maintain
oxyhemoglobin saturation of more than 88%.
• In these situations, supplemental oxygen is connected to
the PAP device outlet and not the mask.
• Patients who were on supplemental oxygen before PAP
titration are likely to need a higher amount of oxygen
with the PAP device because of higher flow rates
reducing the effective oxygen concentration for a given
supplemental oxygen flow.
• Ideally in those patients who required supplemental
oxygen or upward titration of the previously used
oxygen, an arterial blood gas is performed the following
day, usually within a few minutes of waking, to assess
for hypercapnia.