Validation of Nasal Pressure for the Identification of Apneas/Hypopneas during Sleep

Heitman, Steven J.; Atkar, Raj; Hajduk, Eric A.; Wanner, Richard A.; Flemons, W. Ward

doi:10.1164/rccm.2105085

Cited by 75 publications

(46 citation statements)

References 20 publications

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“…Moreover, its reliance on flow limitation leads to ambiguous results. Although we are currently using both techniques for clinical application, it is important to remember that some of the data in our study were gathered before nasal cannula was validated by Heitman et al (2002).The American Academy of Sleep Medicine (AASM) Task Force suggested that differentiation of apnoeas from hypopnoeas was not necessary in clinical practice because both event types share a common pathophysiology and clinical consequences (AASM 1999). The PSG register was analyzed over periods of 30 s and during sleep phases I, II, III, IV and rapid eye movement, according to R&K rules (Rechtschaffen and Kales 1968).…”

Section: Subjects and Signalsmentioning

confidence: 99%

Nonlinear characteristics of blood oxygen saturation from nocturnal oximetry for obstructive sleep apnoea detection

Álvarez¹,

Hornero²,

Abásolo³

et al. 2006

Physiol. Meas.

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Nocturnal oximetry is an attractive option for the diagnosis of obstructive sleep apnoea (OSA) syndrome because of its simplicity and low cost compared to polysomnography (PSG). The present study assesses non-linear analysis of blood oxygen saturation (SaO 2 ) from nocturnal oximetry as a diagnostic test to discriminate between OSA positive and OSA negative patients. A sample of 187 referred outpatients, clinically suspected of having OSA, were studied using nocturnal oximetry performed simultaneously with complete PSG. A positive OSA diagnosis was found for 111 cases, while the remaining 76 cases were classified as OSA negative. The following oximetric indexes were obtained: cumulative time spent below a saturation of 90% (CT90), oxygen desaturation indexes of 4% (ODI4), 3% (ODI3) and 2% (ODI2), and the delta index (∆ index). SaO 2 records were subsequently processed applying two non-linear methods: central tendency measure (CTM) and Lempel-Ziv (LZ) complexity. Significant differences (p < 0.01) were found between OSA positive and OSA negative patients. Using CTM we obtained a sensitivity of 90.1% and a specificity of 82.9%, while with LZ the sensitivity was 86.5% and the specificity was 77.6%. CTM and LZ accuracy was higher than that provided by ODI4, ODI3, ODI2 and CT90. The results suggest that non-linear analysis of SaO 2 signals from nocturnal oximetry could yield useful information in OSA diagnosis.

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Section: Subjects and Signalsmentioning

confidence: 99%

Nonlinear characteristics of blood oxygen saturation from nocturnal oximetry for obstructive sleep apnoea detection

Álvarez¹,

Hornero²,

Abásolo³

et al. 2006

Physiol. Meas.

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“…As expected, indices derived from the nasal pressure sensor alone were almost always larger than from the combina- AHI from a nasal pressure transducer and thermal sensor. 10,[29][30][31][32][33] Consistently, these studies reported the detection of a higher number of apneas when a nasal pressure transducer is used, compared with a thermal sensor, with differences ranging from 30% to 50%. 34,35 This is similar to this study, in which the mean difference between AI np and AI th was 5.3 (4.0, 6.7) events per hour (mean, 95% confidence interval), a difference of 51%.…”

Section: Signal Qualitymentioning

confidence: 58%

“…The nasal cannula responds rapidly and produces a close approximation of the flow past the cannula throughout the breath. 27,28 Nasal pressure transducers record only nasal airflow, meaning that they will overestimate the breathing disturbance in the presence of oral breathing.…”

Section: Discussionmentioning

confidence: 99%

AASM Criteria for Scoring Respiratory Events: Interaction between Apnea Sensor and Hypopnea Definition

Thornton

Singh

Ruehland

et al. 2012

Sleep

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425Choice of Apnea Sensor-Thornton et al reduction and the sensor to be used for apnea detection. The guidelines require that "the sensor to detect absence of airflow for identification of an apnea is an oronasal thermal sensor." 1 The alternative sensor for apnea detection, and the AASM recommended sensor for hypopnea detection, is nasal pressure. These recommendations supercede those in the AASM consensus report of 1999, also known as "Chicago Criteria," 9 which had emphasized nasal pressure as a semi-quantitative measure of airflow and recommended against the routine use of thermal sensors.Despite the AASM recommendations, there is no direct evidence to support the need for both sensors. Nasal-pressure sensors are less sensitive to low levels of flow 10,11 and will not detect oral airflow; hence, it may be that some apneas scored by nasal pressure would be scored as hypopneas with the addition of thermal sensors. It might also follow that there will be little or no net effect on the AHI but simply a shift between event categories-from apnea to hypopnea. On the other hand, because the apnea definition does not require an associated oxygen desaturation or cortical arousal, it is at least possible that apneas scored with nasal pressure alone would not qualify as an apnea or hypnopea with the addition of a thermal sensor, resulting in a reduction in the AHI. INTRODUCTIONIn 2007, the American Academy of Sleep Medicine (AASM) published the Manual for the Scoring of Sleep and Associated Events.1 Following the publication of the manual, there have been a number of criticisms 2-7 ; the major criticism has been the endorsement by the AASM of 2 quite disparate definitions of hypopnea.6,7 Quantification of respiratory events is critical to the diagnosis of sleep apnea, with the apnea-hypopnea index (AHI) being the primary metric for determination of abnormality and severity; the 2 definitions have been shown to result in substantial differences in AHI. 6,8 The AASM manual also clarified the definition of apnea, providing rules for measuring event duration, the extent of airflow Study Objectives: To examine the impact of using a nasal pressure sensor only vs the American Academy of Sleep Medicine (AASM) recommended combination of thermal and nasal pressure sensors on (1) the apnea index (AI), (2) the apnea-hypopnea index (AHI), where the AHI is calculated using both AASM definitions of hypopnea, and (3) the accuracy of a diagnosis of obstructive sleep apnea (OSA). Design: Retrospective review of previously scored in-laboratory polysomnography. Setting: A tertiary-hospital clinical sleep laboratory. AASM CRITERIA FOR SCORING RESPIRATORY EVENTS Patients or Participants:One hundred sixty-four consecutive adult patients with a potential diagnosis of OSA, who were examined during a 3-month period. Interventions: N/A. Measurements and Results: Studies were scored with and without the use of the oronasal thermal sensor. AIs and AHIs, using the nasal pressure sensor alone (AI np and AHI np ), were compared with those using both a...

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“…Our finding of general comparability of RIP and PNT is similar to conclusions of earlier studies. [17][18][19] Polysomnography is the current reference standard for the diagnosis of sleep disordered breathing. Technology that produces signals that accurately reflect respiratory flow and effort while remaining free of artifact is considered fundamental for reliable identification of abnormal respiratory events.…”

Section: Comparison Of Montage 1 and 3: Influence Of Using Pvdfb Withmentioning

confidence: 99%

“…Studies have shown that nasal pressure transduction agrees well with reference standard pneumotachography in the identification of apnea and hypopnea. 18,19 Thermistry has not proven to be a reliable measure of airflow, although, because of the high sensitivity and nonlinear response characteristics of the PNT, thermistry has been endorsed to distinguish obstructive apneas from hypopneas. 20,21 Currently, the AASM also recommends the use of RIP to determine breathing effort and as an alternative to NPT for hypopnea detection.…”

Section: Comparison Of Montage 1 and 3: Influence Of Using Pvdfb Withmentioning

confidence: 99%

Validation of a Polyvinylidene Fluoride Impedance Sensor for Respiratory Event Classification during Polysomnography

Koo

Drummond²,

Surovec

et al. 2011

Journal of Clinical Sleep Medicine

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Study Objectives: The AASM has recommended specifi c sensors in measuring apnea and hypopnea based on published reliability and validity data. As new technology emerges, these guidelines will need revision. Polyvinylidene fl uoride (PVDF) measures impedance and can be incorporated into a belt to approximate airfl ow and respiratory effort. We compared respiratory event detection using PVDF impedance belts (PVDFb), respiratory inductance plethysmography (RIP), and nasal-oral pneumotachography (PNT). Methods: First, in a clinical setting, 50 subjects (median AHI 26) undergoing polysomnography were fi tted with PVDFb and standard sensors. Studies were scored in 4 independent passes using 4 respiratory montages (M); M1: nasal pressure transduction (NPT), thermistry, and RIP; M2: NPT, thermistry, and PVDFb; M3: thermistry and PVDFb; M4: PVDFb alone. Each experimental montage (M2-M4) was compared to the reference standard (M1) for total apneas and hypopneas. In a second experimental study, respiratory event detection was compared across a series of breathing trials for PVDFb, RIP, and PNT in normal subjects. Agreement was evaluated with intraclass correlation coeffi cient (ICC), κ statistics, and Bland-Altman plots. Results: ICCs comparing event numbers by M1 to M 2, 3, and 4 were: 0.99, 0.93, and 0.91, respectively. Almost identical numbers of events were identifi ed for M 1 and M2 (177.5 ± 122.7 vs 177.6 ± 123.2). Event subtypes also were comparable. PVDFb was less sensitive than PNT but no different than RIP in detecting decreased breathing amplitude. Conclusions S C I E N T I F I C I N V E S T I g A T I O N ST he sleep related breathing disorders are characterized by repetitive episodes of complete or partial airfl ow cessation which result in apnea or hypopnea, respectively. Chief among these breathing disorders is obstructive sleep apnea (OSA) which affects approximately 9% of women and 24% of men in the general population.1 The principal metric refl ecting OSA severity, the apnea-hypopnea index (AHI), quantifi es the number of apneas and hypopneas per hour of sleep. The AHI has proven a valuable measure, as it correlates with daytime sleepiness, risk of cardiovascular disease, and mortality.2-5 For this reason, there has been much emphasis placed on methods for ensuring the reproducibility and validity of apnea and hypopnea detection.In 2007, the American Academy of Sleep Medicine (AASM) published recommendations for measuring apneas and hypopneas based on evidence on the reliability and validity of alternative sensors and scoring approaches and consensus opinion. In this effort, technology reviewed for the estimation of airfl ow included the heat-sensitive thermistor, nasal pressure transduction (NPT), and respiratory inductance plethysmography (RIP). Based upon available evidence, thermistry was deemed appropriate for detecting apnea, while use of either NPT or RIP was recommended to identify hypopnea. It was recognized that distinguishing obstructive from central respiratory events requires identifi cation ...

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Validation of Nasal Pressure for the Identification of Apneas/Hypopneas during Sleep

Cited by 75 publications

References 20 publications

Nonlinear characteristics of blood oxygen saturation from nocturnal oximetry for obstructive sleep apnoea detection

Nonlinear characteristics of blood oxygen saturation from nocturnal oximetry for obstructive sleep apnoea detection

AASM Criteria for Scoring Respiratory Events: Interaction between Apnea Sensor and Hypopnea Definition

Validation of a Polyvinylidene Fluoride Impedance Sensor for Respiratory Event Classification during Polysomnography

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