NWO SEM Sleep Society
LITERATURE WATCH

F. Positive Pressure Treatment; Complications; Compliance

Chest. 2005 Oct;128(4):2138-40.

Chest. 2005 Oct;128(4):2141-50

Chest. 2005 Oct;128(4):2151-8

Eur Respir J. 2005 Oct;26(4):679-85

Chest. 2005 Sep;128(3):1882-4

Sterile Water Is Unnecessary in a Continuous Positive Airway Pressure Convection-Type Humidifier
in the Treatment of Obstructive Sleep Apnea Syndrome
Chest. 2005 Oct;128(4):2138-40.
•        The convection-type humidifier produces water vapor but does
not aerosolize the water.
•        Bacteria, other microorganisms, or even solutes that may be
contained in the water cannot be transported into the air and thus will
not be deposited in the lung.
•        In order to avoid respiratory tract infections, sterile water is not
required, at least in this particular humidifier. They suggest that non-
sterile tap water is probably a safe alternative.

Bilevel Positive Airway Pressure Worsens Central Apneas During Sleep
Chest. 2005 Oct;128(4):2141-50
•        BLPAP was more likely to worsen than improve CSR (p =
0.002), non-CSR central apneas (p < 0.001), and CSR or PB (p <
0.001).
•        CSR (p = 0.03) and non-CSR central apneas (p = 0.01) were
more likely to worsen with BLPAP (24% and 23%, respectively) than
with CPAP (11% and 8%). Central events (p = 0.04) and CSR (p =
0.009) were more likely to worsen during BLPAP in patients with
baseline CSR or PB (62% and 48%, respectively) than develop in
those without baseline CSR or PB (34% and 18%).
•        Higher BLPAP differences worsened central events in 28% of
patients, while 7% improved (p = 0.02).
•        BLPAP often increases the frequency of CSR and non-CSR
central apneas during sleep. Since CSR has adverse effects on cardiac
function and sleep, it is important to consider this possible adverse
effect of BLPAP
(CSR = Cheyne Stokes Respiration; PB = Periodic Breathing; BLPAP
= Bi Level Positive Airway Pressure)

Effect of Heated Humidification on Compliance and Quality of Life in Patients With Sleep Apnea
Using Nasal Continuous Positive Airway Pressure
Chest. 2005 Oct;128(4):2151-8
•        Patients received heated humidification at CPAP initiation in the
treatment group.
•        In the control group, patients could receive heated humidification
only if they had upper airway symptoms that could not be treated
successfully with simpler measures.
•        Patients were followed up at 1 month, 3 months, and 12 months.
Outcome measures were compliance with nasal CPAP (mean hours
per night at effective pressure), quality of life as measured by the
Calgary sleep apnea quality of life index, subjective sleepiness
measured with the Epworth sleepiness scale, and CPAP side effects.
•        There was no difference in CPAP compliance between groups.
Quality of life and subjective sleepiness improved in both groups with
nasal CPAP therapy, but there was no difference in the extent of
improvement between groups.
•        The overall CPAP side effect score was similar in both groups,
but individual symptoms of dry nose and dry mouth and throat were
significantly lower in the heated humidification group.

Use of heated humidification during nasal CPAP titration in obstructive sleep apnoea syndrome
Eur Respir J. 2005 Oct;26(4):679-85
•        Nasal symptoms associated with the use of nasal continuous
positive airway pressure (nCPAP) in obstructive sleep apnoea (OSA)
can adversely impact on patients' tolerance, acceptance and
adherence to nCPAP therapy. Regular use of heated humidification is
effective in alleviating these symptoms and improve patient comfort.
•        Examined  the use of heated humidification during a single night
laboratory nCPAP titration in untreated OSA patients and its effect on
nasal symptoms, nasal airway resistance (NAR), effective pressure
and treatment tolerability and acceptance.
•        Total inspiratory NAR, before (0.36±0.09 (placebo) versus 0.33
±0.09 kPa•L–1•s–1) and after nCPAP (0.47±0.11 versus 0.29±0.04
kPa•L–1•s–1) were not significantly different between the groups.
•        No difference was found in the frequency and severity of
nasopharyngeal symptoms, therapeutic pressure and subjective
response to nCPAP.
•        In conclusion, heated humidification during the initial nasal
continuous positive airway pressure titration offers no additional benefit
in nasal physiology, symptoms or subjective response to nasal
continuous positive airway pressure, and, therefore, should not be
routinely recommended.

Cerebrospinal Fluid Leak and Meningitis Associated With Nasal Continuous Positive Airway
Pressure Therapy
Chest. 2005 Sep;128(3):1882-4
•        Clear rhinorrhea is a common symptom in patients with
obstructive sleep apnea (OSA) and may worsen with continuous
positive airway pressure therapy.
•        Clear rhinorrhea can also be the presenting symptom of
cerebrospinal fluid (CSF) leak, which is evidence of a communication
between the subarachnoid space and the nasal cavity or sinuses.
•        They report two patients with OSA in whom CSF leak developed
following the institution of nCPAP therapy. In one patient, the rhinorrhea
was complicated by meningitis. Both patients underwent successful
repair of their defects. One patient successfully restarted nCPAP
therapy, while the other refused it.