Correlation between CPAP pressure, calculates by titration with autocpap, and the arithmetic mean of the Hoffstein and Series formulas

Introduction: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is considered a public health problem. To measure the level of pressure required, the most appropriate methods are the titration with polysomnography or autocpap, but for care and economic issues, different methods have been developed, such as empirical calculation using mathematical estimation with different formulas. We studied the correlation between the empirical pressure of the arithmetic mean of the Hoffstein and Series formulas and the median pressure after an autoCPAP titration Methods: Prospective study in which 50 patients diagnosed with SAHS, we performed autoCPAP for one night, and we analyzed the correlation between the median pressure obtained by this method and the mean pressure between the Hoffstein and Series formulas Results: 50 autoCPAP with 34 men (68%) and 16 women (32%) with average age: 53.70 years. Mean BMI 31.7; Average AHI by polygraphy: 53 and average AHI by autoCPAP: 2.86. A median pressure of 36 autoCPAP of: 8.478 cmH20 was obtained. And of the formulas: 6.7456, for Hoffstein, and 9.3922 cm H20 for Series respectively, and 8.3792 was the arithmetic mean between both. The correlation between the median of the autoCPAP and the mean of the two formulations was: 0.0988. Subsequently, the 50 autoCPAP were analyzed, without excluding studies with leaks greater than 25 l/min, and no differences were found with the previous results. Conclusions: In our study, limited by a low n, there is a very good correlation between the mean of both formulas and the average pressure of the autoCPAP, which invites us to continue it, to see if with a larger sample, this relationship is confirmed.