Escrib

1
Escribá J.a, Tenías JM.d, Canet T.b, Hoyo B. c,
López E. c, Casaña S. a, Moliner J. aClinical
Neurophysiology Departments of Doctor Peset
University Hospital (Valencia) a, Virgen de los
Lirios Hospital (Alcoi) b, and Lluis Alcanyís
Hospital (Xàtiva) c. Preventive Medicine
Department of Lluis Alcanyís Hospital d
(Xàtiva)?
MULTICENTER STUDY ABOUT AGREEMENT BETWEEN CPAP
TITRATION BY POLISOMNOGRAPHY AND PREDICTIVE
FORMULA IN SAHS PATIENTS
Table 1. Descriptive statistics for CPAP
titration and independent variables
INTRODUCTION The gold-standard option for Sleep
Apnea Hypopnea Syndrome (SAHS) is the CPAP
titrated by polisomnography. However, some
formulas based on anthropometrics and technical
variables have been defined recently in order to
try to simplify the treatment. (1-4) For
example, Miljeteig Hofstein designed a
predictive formula in 1993 to determine the
initial CPAP pressure in SAHS Canadian patients
(4) and this method has been widely used in our
environment without previous scientific
validation. PURPOSE Analyse the unknown
concordance between CPAP titration by
polisomnography and by the Miljeteig and
Hofsteins predictive formula in a multicenter
population in our region.
All results expressed as mean (Standard
deviation)? CPAP titration 0,16 x BMI 0,13
x Neck circumference 0,04 x Apnea-hipopnea
index - 5,12
Hospital de Xàtiva HLX
METHODS We analysed 830 patients (mean age 53,3
years, standard deviation 11,5 years, 85 males)
from 3 different hospitals from Region of
Valencia (Spain) after a complete data collection
and a CPAP pressure estimation by PSG titration
and the predictive formula. Our samples were
from 2 Secondary Hospitals (Lluis Alcanyis
Hospital-Xativa HLX and Verge dels Lliris
Hospital-Alcoi HVA) and 1 Reference Sleep
Disorders Hospital (Doctor Peset University
Hospital-Valencia HPV) Agreement beyond chance
between both methods was judged by Lins
coefficient (Rho). Paired differences were
plotted against pair-wise means by Bland-Altman
plots.
Hospital de Alcoi HVA
Hospital Dr Peset HPV
RESULTS The average CPAP titration by
polisomnography ranges from 7.4 (HVA) to 10.9
(HLX) cm H20. Descritptive statistics for the
three hospitals are shown in Table 1. We found
just an slight agreement in HPV (Rho 0.102 IC95
-0.13 a 0.33) and HLX (Rho 0.19 IC95 0.14 a
0.24) and a moderate agreement in HVA (Rho 0.45
IC95 0.32 a 0.59). Bland-Altman plots showed
this poor concordance in the three centers
(Figure 1).
Figure 1. Bland-Altman plots

• CONCLUSIONS
• The Miljeteig Hofsteins predictive formula
  does not show a good concordance in our sample.
  Besides, this method means that up to 33 of the
  patients need more consultations to readjust the
  CPAP pressure (5) and it is showed that SAHS
  patients have better compliance in attended
  polisomnography titration (6) .
• According to these results, we rather recommend
  CPAP titration by polisomnography in SAHS
  patients until more studies would be able to
  prove if there is another alternative method of
  titration with enough scientific evidence to
  replace the polisomnography.

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