Abstract
We investigated differences in the depth of
hypoxia produced by apneic events of the same
duration (30 seconds) amongst patients with different
degrees of OSAS according to their AIs
(apnea indices). The relationship between apnea
duration (seconds) and fall in oxygen saturation
(%) was evaluated by means of a linear regression
analysis. The fall induced by a 30-second apnea
event was designated as the “oxygen desaturation
value 30” (ODV30). We analyzed the polysomnographic
recordings of 122 OSAS patients who
showed significant correlations (p<0.01) between
apnea duration and subsequent fall in oxygen saturation
and calculated their respective ODV30.
We evaluated the influence of AI and BMI on
ODV30 by multi-comparison and found out that
standardized partial regression coefficients of
BMI and AI were 0.578 and 0.148, respectively
(multi-regression analysis, SPSS). BMI was
proved to be more influential on ODV30 than AI
was.
On the other hand, the ODV30 of mild, moderate
and severe OSAS patients was 8.84 ± 2.62%
(Mean ± S.D.), 8.25 ± 2.45% and 10.59 ± 3.32%,
respectively.
Our study shows that fall in oxygen saturation is
particularly extensive in severe OSAS patients
and that fall in oxygen saturation is deepened as
obesity increases.
We think ODV30 is a useful variable for evaluating
OSAS.
