Am. J. Respir. Crit. Care Med., Volume 162, Number 1, July 2000, 87-93

Comparison of Esophageal Pressure with Pulse Transit Time as a Measure of Respiratory Effort for Scoring Obstructive Nonapneic Respiratory Events

JÉRÔME ARGOD, JEAN-LOUIS PÉPIN, ROBIN P. SMITH, and PATRICK LÉVY

Department of Respiratory Medicine and Sleep Laboratory, and PRETA Laboratory TIMC UMR CNRS 5525, University Hospital, Grenoble, France; Chest Unit, Victoria Hospital, Kirkcaldy, Scotland

Obstructive nonapneic respiratory events (ONAREs) are much more difficult to detect and classify than apneas unless sensitive measures of respiratory effort and airflow are employed. The aim of this study was to compare two measures of respiratory effort, esophageal pressure monitoring (Pes) and pulse transit time (PTT), for scoring of ONAREs by visual analysis. Nine men (age 49 ± 10 yr) with mild to moderate sleep apnea syndrome (AHI of 25.1 ± 10.8/h) were studied and 340 ONAREs (hypopneas and upper airway resistance episodes) were randomly selected for scoring by two experienced observers. Each observer blindly scored each ONARE twice (once with Pes and once with PTT) with a concurrent pneumotachography trace available for airflow quantification. This permitted the respiratory events scored with PTT to be compared with those scored with Pes, and in addition interobserver variability could be assessed for each signal. Even though standard criteria were used for scoring, there was significant interobserver variability for both Pes (29.7%) and PTT (37.1%). Taking those events for which there was agreement between the observers, PTT had a sensitivity of 79.9% and a positive predictive value of 91.2% (using Pes as the gold standard). In those ONAREs for which there was agreement between the two observers there was a larger percentage reduction in airflow compared to ONAREs that did not concur (51 versus 30.3%, p < 0.001), a larger increase in respiratory effort as assessed by PTT (slope of PTT: 23.1 versus 14.3 arbitrary units, p < 0.01), and a higher incidence in autonomic microarousals detected with PTT (90 versus 45% of ONAREs, p < 0.006). Subtle respiratory events are more difficult to detect than apneas or frank hypopneas. When comparing PTT with esophageal pressure in detecting those events the sensitivity of PTT is good but limited when the reduction in airflow, the increase in respiratory effort, or the arousal reaction is the less clear. However, PTT appears to be a good noninvasive alternative to Pes in the detection of nonapneic obstructive respiratory events, and its ability to detect autonomic arousal gives this physiological signal added clinical usefulness.

This article has been cited by other articles:

				S. E. Brietzke, E. S. Katz, and D. W. Roberson Pulse Transit Time as a Screening Test for Pediatric Sleep-Related Breathing Disorders Arch Otolaryngol Head Neck Surg, October 1, 2007; 133(10): 980 - 984. [Abstract] [Full Text] [PDF]

				S. Mazza, J-L. Pepin, B. Naegele, E. Rauch, C. Deschaux, P. Ficheux, and P. Levy Driving ability in sleep apnoea patients before and after CPAP treatment: evaluation on a road safety platform Eur. Respir. J., November 1, 2006; 28(5): 1020 - 1028. [Abstract] [Full Text] [PDF]

				J. Y. A. Foo, S. J. Wilson, A. P. Bradley, G. R. Williams, M.-A. Harris, and D. M. Cooper Use of Pulse Transit Time To Distinguish Respiratory Events From Tidal Breathing in Sleeping Children Chest, October 1, 2005; 128(4): 3013 - 3019. [Abstract] [Full Text] [PDF]

				J.-L. Pepin, N. Delavie, I. Pin, C. Deschaux, J. Argod, M. Bost, and P. Levy Pulse Transit Time Improves Detection of Sleep Respiratory Events and Microarousals in Children Chest, March 1, 2005; 127(3): 722 - 730. [Abstract] [Full Text] [PDF]

				S. Mazza, J-L. Pepin, B. Naegele, J. Plante, C. Deschaux, and P. Levy Most obstructive sleep apnoea patients exhibit vigilance and attention deficits on an extended battery of tests Eur. Respir. J., January 1, 2005; 25(1): 75 - 80. [Abstract] [Full Text] [PDF]

				C. Saint Raymond, G. Bettega, C. Deschaux, J. Lebeau, B. Raphael, P. Levy, and J.-L. Pepin Sphincter Pharyngoplasty as a Treatment of Velopharyngeal Incompetence in Young People: A Prospective Evaluation of Effects on Sleep Structure and Sleep Respiratory Disturbances Chest, March 1, 2004; 125(3): 864 - 871. [Abstract] [Full Text] [PDF]

				J.F. Masa, J. Corral, M.J. Martin, J.A. Riesco, A. Sojo, M. Hernandez, and N.J. Douglas Assessment of thoracoabdominal bands to detect respiratory effort-related arousal Eur. Respir. J., October 1, 2003; 22(4): 661 - 667. [Abstract] [Full Text] [PDF]

				J. Pagani, M. P. Villa, G. Calcagnini, A. Alterio, R. Ambrosio, F. Censi, and R. Ronchetti Pulse Transit Time as a Measure of Inspiratory Effort in Children Chest, October 1, 2003; 124(4): 1487 - 1493. [Abstract] [Full Text] [PDF]

				D M Smith and J R Stradling Can mandibular advancement devices be a satisfactory substitute for short term use in patients on nasal continuous positive airway pressure? Thorax, April 1, 2002; 57(4): 305 - 308. [Abstract] [Full Text] [PDF]

				C Tasker, J H Crosby, and J R Stradling Evidence for persistence of upper airway narrowing during sleep, 12 years after adenotonsillectomy Arch. Dis. Child., January 1, 2002; 86(1): 34 - 37. [Abstract] [Full Text] [PDF]

				M. J. TOBIN Sleep-disordered Breathing, Control of Breathing, Respiratory Muscles, Pulmonary Function Testing, Nitric Oxide, and Bronchoscopy in AJRCCM 2000 Am. J. Respir. Crit. Care Med., October 15, 2001; 164(8): 1362 - 1375. [Full Text] [PDF]