Comparison of nasal pressure transducer and thermistor for detection of respiratory events during polysomnography in children.
OBJECTIVE
The results of small studies have suggested that a nasal-cannula pressure transducer has a higher sensitivity than a thermistor in detecting hypopneas and diagnosing sleep-disordered breathing in both adults and children. We compared a thermistor alone, and in conjunction with a pressure transducer, for detection of sleep-disordered breathing in children during in-home polysomnography.


METHODS
Retrospective analysis of a subsample of a prospective cohort study.


METHODS
Students attending elementary school in the Tucson Unified School District.


METHODS
A subsample of the Tucson Children's Assessment of Sleep Apnea study population.


RESULTS
Polysomnographic recordings of 40 children (24 girls and 16 boys, mean age 9.2 +/- 1.7 years; range 6-11 years) were analyzed to compare the detection of sleep-disordered breathing events by 2 different methods of measuring airflow: thermistor alone and thermistor with nasal-cannula pressure transducer (transducer) used simultaneously. The transducer detected all the respiratory events detected by the thermistor, but the thermistor detected only 84% of the transducer-defined events. Consequently, the transducer-derived mean respiratory disturbance index was higher than that detected by the thermistor (7.0 +/- 3.8 vs 5.9 +/- 3.4, P < .001). The bias error between transducer respiratory disturbance index and thermistor respiratory disturbance index on a Bland-Altman plot was 1.08 (95% confidence interval, 0.8 - 1.4). There was good agreement between the thermistor and the transducer for making the diagnosis of sleep apnea using a cutoff of a respiratory disturbance index greater than 5 (kappa = 0.69). The quality of the tracings with the transducer was comparable to that of the thermistor, but the transducer dislodged more frequently.


CONCLUSIONS
The use of a nasal transducer in conjunction with a thermistor was more sensitive than the thermistor alone in detecting sleep-disordered breathing in children during unattended polysomnography.
Budhiraja
Rohit
R
Division of Pulmonary & Critical Care, Department of Medicine, Southern Arizona Veterans Affairs Health Care System, Tucson, AZ 85723, USA. rohit.budhiraja@med.va.gov
Goodwin
James L
JL
Parthasarathy
Sairam
S
Quan
Stuart F
SF
D002404:Catheterization; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009296:Nasal Cavity; D017286:Polysomnography / Q000295:instrumentation*; D011312:Pressure; D011446:Prospective Studies; D012189:Retrospective Studies; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000503:physiopathology*; D014159:Transducers