Chest
Volume 119, Issue 2, February 2001, Pages 442-450
Journal home page for Chest

Clinical Investigations
Sleep and Breathing
Performance of Nasal Prongs in Sleep Studies: Spectrum of Flow-Related Events

https://doi.org/10.1378/chest.119.2.442Get rights and content

Objectives

The use of nasal prongs connected to apressure transducer is a noninvasive, sensitive method to detectrespiratory events, and can be easily implemented in routine sleepstudies. Moreover, its good time response allows the detection ofseveral flow-related phenomena of high interest, in addition to apneaand hypopnea. The aims of the study were to examine the quality andperformance of the nasal prong flow signal, and to describe otherflow-related events during full-night polysomnography studies.

Methods

Twenty-seven subjects were studied (16 malesubjects; mean ± SD age, 49 ± 14 years; mean body mass index, 27 ± 4 kg/m2): 15 subjects recruited from the generalpopulation and 12 consecutive patients with suspected sleepapnea/hypopnea syndrome (SAHS).

Results

A blindanalysis of the respiratory events detected both by nasal prongs andthermistor was done. The quality of the nasal prong signal recordingswas considered optimal for scoring purposes in 78% of cases, and norecording was considered uninterpretable. The nasal prong signaldetected additional flow-related events not observed by the thermistor:(1) short and long (> 2 min) periods of inspiratory flow limitationmorphology without decrease in the amplitude of the signal; (2) periodsof mouth expiration; and (3) snoring. The apnea/hypopnea index wassignificantly higher with the nasal prong scoring (18 vs 11[p < 0.05] in the general population and 37 vs 27 [p < 0.001]in the group with suspected SAHS).

Conclusions

Theincorporation of nasal prongs in routine full-night studies is anattainable technical option that provides adequate recordings in mostcases. Additionally, relevant information not scored by thermistors isobtained on flow-related respiratory events, thus increasing diagnosticaccuracy.

Section snippets

Study Subjects

Twenty-seven subjects were studied during an all-nightpolysomnography in our sleep laboratory. The subjects were recruitedfrom two different groups: (1) a sample of 15 subjects from the generalpopulation recruited in the context of a prevalence study, and (2) 12consecutive patients referred to the sleep laboratory with suspectedsleep apnea/hypopnea syndrome (SAHS).

Sleep Study

Each patient was studied with full-night polysomnography, plusthe addition of nasal prongs to the setting. The neurologic

Results

The general characteristics and the sleep parameters of thetwo groups included in this study are shown in Table 1. There were no significant differences between them, with the exceptionof a greater neck circumference in the group of patients with suspected, SAHS.

Discussion

Flow measured through nasal prongs was easily implementedin full-night studies and provided technically optimal recordings inmost cases. None of them showed an uninterpretable nasal prong trace, and only in a small number of sleep studies were there somedifficulties in nasal prong scoring. In addition, nasal prongs allowedus to obtain further information on flow-related events that were notidentified with the conventional thermistor signal: snoring, prolongedand short periods of inspiratory

References (21)

  • >Indications and standards for cardiopulmonary sleep studies: American Thoracic Society Medical Section of the American Lung Association

    Am Rev Respir Dis

    (1989)
  • Practice parameters for the indications for polysomnography and related procedures: Polysomnography Task Force, American Sleep Disorders Association Standards of Practice Committee

    Sleep

    (1997)
  • R Farre et al.

    Accuracy of thermistors and thermocouples as flow-measuring devices for detecting hypopnoeas

    Eur Respir J

    (1998)
  • S Berg et al.

    Comparison of direct and indirect measurements of respiratory airflow: implications for hypopneas

    Sleep

    (1997)
  • RG Norman et al.

    Detection of respiratory events during NPSG: nasal cannula/pressure sensor versus thermistor

    Sleep

    (1997)
  • JM Montserrat et al.

    Evaluation of nasal prongs for estimating nasal flow

    Am J Respir Crit Care Med

    (1997)
  • R Condos et al.

    Flow limitation as a noninvasive assessment of residual upper-airway resistance during continuous positive airway pressure therapy of obstructive sleep apnea

    Am J Respir Crit Care Med

    (1994)
  • JM Montserrat et al.

    Time-course of stepwise CPAP titration: behavior of respiratory and neurological variables

    Am J Respir Crit Care Med

    (1995)
  • SA Clark et al.

    Assessment of inspiratory flow limitation invasively and non invasively during sleep

    Am J Respir Crit Care Med

    (1998)
  • E Ballester et al.

    Nasal prongs in the detection of sleep-related disordered breathing in the sleep apnoea/hypopnoea syndrome

    Eur Respir J

    (1998)
There are more references available in the full text version of this article.

Cited by (68)

  • Prolonged partial obstruction during sleep is a NREM phenomenon

    2018, Respiratory Physiology and Neurobiology
    Citation Excerpt :

    However, the usefulness of the AHI alone to quantify SDB has been criticised because long periods of prolonged partial obstruction without apnoea or hypopnea are common in SDB patients (Anttalainen et al., 2016; Tenhunen et al., 2013). Prolonged partial obstruction causes flow limitation in the nasal pressure signal (Hernandez et al., 2001) and can be assessed quantitatively by measuring oesophageal pressure (see Bao and Guilleminault, 2004). One feasible way to evaluate prolonged partial obstruction is the Emfit mattress sensor.

  • Evaluation of the different sleep-disordered breathing patterns of the compressed tracheal sound

    2015, Clinical Neurophysiology
    Citation Excerpt :

    However, in addition to apneas and hypopneas revealing OSA, sleep recordings consist of other sleep-disordered breathing patterns, as well. These patterns include short flow limitation events associated with an increase in negative oesophageal pressure as well as an arousal, as in the upper airway resistance syndrome (UARS), or sustained low limitation periods, lasting from several minutes up to tens of minutes (Hernandez et al., 2001; Tenhunen et al., 2009). The sustained partial obstruction detected by a sleep mattress sensor has been found to be common especially among postmenopausal women (Polo-Kantola et al., 2003).

  • Emfit movement sensor in evaluating nocturnal breathing

    2013, Respiratory Physiology and Neurobiology
    Citation Excerpt :

    Attention has recently been paid to another type of SDB; prolonged or sustained partial upper airway obstruction (Anttalainen et al., 2007a, 2010; Bao and Guilleminault, 2004). This phenomenon can be assessed either by sustained negative increase in oesophageal pressure or by prolonged flow limitation pattern in the nasal pressure transducer signal (Bao and Guilleminault, 2004; Hernandez et al., 2001). Also the SCSB and the Emfit can serve as non-invasive means to detect prolonged partial obstruction (Kirjavainen et al., 1996; Polo, 1992; Polo et al., 1991; Tenhunen et al., 2011).

View all citing articles on Scopus

Supported by grants FIS 00/0575, SEPAR, CICYT: SAF99–0001, and the, Comissionat per a Universitats i Recerca (1997 SGR 00086) from the, Generalitat de Catalunya.

View full text