MD Conference Express ATS 2013 - (Page 9)
studies demonstrated a significant increase in survival rates
in patients with overlap syndrome that were treated with
CPAP, as compared with overlap syndrome patients not
treated with CPAP and COPD patients [Kouns A, Philips B.
Curr Treat Options Neurol 2011].
S. Javaheri, MD, University of Cincinnati College of
Medicine, Cincinnati, Ohio, USA, discussed the use of nNIV
in patients with heart failure that have sleep-disordered
breathing. The benefits of ASV devices include their ability
to automatically vary the inspiratory support, automatic
CPAP to prevent obstructive events from occurring, and
automatic back-up rate to prevent apnea.
ASV devices can automatically increase inspiratory
support during hypopneas and decrease support during
hyperpnea. Dr. Javaheri pointed out that this feature is
important in patients with heart failure as the mechanisms
that underlie periodic breathing and central sleep apnea
in these patients is oscillations in ventilatory drive. ASV
devices decrease these oscillations. In addition, ASV
devices also initiate a mandatory breath on a timed basis,
aborting the course of an impending apnea. Finally, the
expiratory pressure prevents upper airway closure and
eliminates obstructive events. In the new generation of auto
ASV devices, the expiratory pressure varies automatically
in a similar fashion to auto CPAP devices. These three
features of ASV devices, autoinspiratory pressure support,
auto CPAP and auto back-up rate make ASV devices most
appropriate for mixed/hybrid sleep-disordered breathing
consisting both of central sleep apnea, obstructive sleep
apnea and hypopneas, provided that these events were not
all eliminated by the use of CPAP.
In a study of patients with complex sleep apnea and some
with Hunter-Cheyne-Stokes breathing with central sleep
apnea, Dr. Javaheri pointed out that patients experienced the
greatest benefit with auto ASV and auto ASV advanced, as
compared with CPAP [Javaheri S et al. Sleep 2011].
Meanwhile multiple studies have been performed in
patients with heart failure with various ASV devices. In their
meta-analysis, Sharma and associates [Chest 2012] included
studies of ≥1 week duration comparing ASV to a control
condition (which was subtherapeutic ASV, CPAP, bilevel
positive airway pressure, oxygen therapy, or no treatment)
in adult heart failure patients with sleep apnea. Comparing
ASV to control conditions, the weighted mean difference
in apnea hyponea index (AHI; -15 events/hour; 95% CI,
-21.03 to -8.25) significantly favored ASV. Importantly,
when the crossover studies were compared, AHI decreased
from baseline of about 50 events per hour to 6 per hour with
ASV compared with 21 per hour in control conditions.
These data provide a compelling rationale for largescale randomized controlled trials to assess the clinical
impact of ASV on mortality in heart failure patients.
Currently two trials are ongoing.
Amanda Piper, PhD, Royal Prince Alfred Hospital,
Camperdown, Australia, discussed the efficacy of
different modes of bilevel nNIV in patients with obesity
hypoventilation syndrome (OHS). In a study of 36 OHS
patients with moderate to severe upper airway obstruction
randomized to CPAP or bilevel support in spontaneous
mode for 3 months, similar clinical outcomes were achieved
delete period [Piper AJ et al. Thorax 2008].
A more recent study compared bilevel support in
spontaneous versus spontaneous timed (S/T) mode [Contal
O et al. Chest 2013]. In this study, 10 patients with OHS were
randomized to spontaneous mode, S/T mode with a low backup respiratory rate (BURR), or S/T mode with a high BURR
over 3 nights. A greater number of respiratory events occurred
in patients treated with spontaneous mode, compared
with either of the S/T mode, raising the issue of whether
the spontaneous mode should be used in this population.
However, Prof. Piper pointed out that the study included only
a small number of patients naïve to nNIV therapy with settings
not titrated to the mode used. Nevertheless, data from other
studies suggests more passive ventilation in this population
may yield greater clinical benefits. Prof. Piper also discussed
the use of volume targeted pressure support in OHS, with
a recent large study finding no additional clinical benefit of
this mode over standard bilevel therapy in routine practice
[Murphy PB et al. Thorax 2012].
Prof. Piper also highlighted the importance of titrating
inspiratory support to achieve an adequate tidal volume.
For patients with OHS, 8 to 10 mL/kg of ideal body weight
appears to be a good nocturnal tidal volume target [Murphy
PB et al. Thorax 2012; Budwesier S et al. J Intern Med 2007].
Amy Atkeson, MD, Columbia University College of
Physicians & Surgeons, New York, New York, USA, discussed
the use of nNIV in patients with neuromuscular disorders.
The rationale for treating patients with neuromuscular
disorders with nNIV is that it may help rest overtaxed
respiratory muscles, improvement of muscle strength and
contractility, improvement in respiratory mechanics, and
recruitment of atelectatic and partially atelectatic alveoli.
Early initiation of nNIV therapy in patients with
neuromuscular disorders, such as ALS, may confer a
survival advantage. Dr. Atkeson highlighted several studies
that demonstrated a reduced decline in FVC [Kleopa KA et
al. J Neurol Sci 1999] and cost-effectiveness [Gruis KL et al.
Health Serv Res 2005]. However, Dr. Atkeson pointed out
that although the evidence is generally positive, it is weak
and more research is required to determine the optimal use
of nNIV in patients with neuromuscular disorders.
Although additional research is required in many
cases to determine the benefit and/or optimal use of nNIV
in conditions that cause sleep disorder, nNIV appears to
offer the promise of improved outcomes in patients with
sleep disorders.
Official Peer-Reviewed Highlights From the American Thoracic Society International Conference 2013
9
Table of Contents for the Digital Edition of MD Conference Express ATS 2013
MD Conference Express ATS 2013
Contents
Prevention and Early Treatment of Acute Lung Injury
Nocturnal Noninvasive Ventilation Improves Outcomes in Multiple Disorders
Hospital Readmissions: Challenges and Opportunities
EBUS-TBNA: Accurate and Safe for Detecting Sarcoidosis
Data Link Obstructive Sleep Apnea and Type 2 Diabetes
Statin Use Improves Respiratory-Related Mortality in Patients With COPD
Addition of Spironolactone to Ambrisentan May Be a Novel Treatment Strategy to Improve Outcome in Patients With PAH
Haloperidol Does Not Prevent Delirium in Ventilated ICU Patients
Beraprost Plus Sildenafil Effective in Pulmonary Arterial Hypertension
Dupilumab Is Safe and Effective for Controlling Asthma Attacks
Once-Daily QVA149 Improves Breathlessness in COPD Patients
CPAP in CVD and OSA Does Not Significantly Improve Cardiovascular Biomarkers
CPAP Reduces BP in Patients With Resistant Hypertension and Obstructive Sleep Apnea
Effects of Obesity on COPD
Pulmonary Embolism
Ventilator-Associated Pneumonia
Lung Cancer Screening
Idiopathic Pulmonary Fibrosis
Non-Small-Cell Lung Cancer
MD Conference Express ATS 2013
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