ADEQUACY OF PRESCRIBING NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE THERAPY FOR THE SLEEP-APNEA HYPOPNEA SYNDROME ON THE BASIS OF NIGHT TIME RESPIRATORY RECORDING VARIABLES
Jm. Montserrat et al., ADEQUACY OF PRESCRIBING NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE THERAPY FOR THE SLEEP-APNEA HYPOPNEA SYNDROME ON THE BASIS OF NIGHT TIME RESPIRATORY RECORDING VARIABLES, Thorax, 50(9), 1995, pp. 969-971
Background - The increased demand of full polysomnographic studies, no
t only for diagnostic purposes but also for continuous positive airway
pressure (CPAP) titration, has produced long waiting lists. Simpler m
ethods are therefore needed to avoid having to refer all patients for
full polysomnography. The hypothesis that CPAP therapy for the sleep a
pnoea/hypopnoea syndrome (SAHS) can be performed exclusively on the ba
sis of recording night time respiratory variables was tested. Methods
- The level of CPAP in a group of 41 patients (three women) of mean (S
D) age 52 (10) years, body mass index 31 . 5 (4 . 4) kg/m(2), and apno
ea/hypopnoea index (AHI) 53(16) events/hour was measured. During a two
week period CPAP titration was performed in a random order in two set
tings: (1) in the sleep laboratory using full polysomnography; and (2)
in the respiratory ward using equipment which continuously recorded a
nd displayed pulse oximetry, airflow, chest and abdominal motion, and
body position. The level of CPAP was increased progressively until apn
oea, hypopnoea, snoring, and thoracoabdominal paradox disappeared. Res
ults - No differences in CPAP levels (9 . 34(2 . 2) versus 9 . 68(2 .
1) cm H2O) were found between full polysomnography and night time resp
iratory recordings. The accuracy of the measurement of both procedures
showed good agreement. Only one patient showed a significant differen
ce in CPAP level requirements between the two methods. Conclusions - N
ight time respiratory recording is sufficient to permit a reasonable c
hoice of CPAP levels to abolish all the respiratory disturbances in mo
st of the patients studied.