CPAP Pressure Prediction Calculation. An Alternative to the Difficulty of Performing a Titration Within the Context of the COVID19 Pandemic

Abstract Introduction: The treatment of choice for the obstructive sleep apnea-hypopnea syndrome (OSAHS) is continuous positive air pressure in the airway (CPAP), titrating the effective pressure that eliminates obstructive events through validated methods. From the beginning of the COVID 19 pandemic, it has been recommended that conventional titration should be postponed, replacing it with self-adjusting equipment. In our population, access to these devices is difficult. Objective: To show whether there is a difference between the CPAP pressure level calculated through a prediction formula and the pressure determined by titration under polysomnography. Materials and Methods: We included patients with OSAHS who underwent effective CPAP titration and compared it with the cal culated CPAP by the Miljeteig and Hoffstein formula. Results: We included medical records of 583 patients, (56%) men, 51 years (41-61), apnea-hypopnea index (AHI) of 51.3 (29.2 -84.4), calculated CPAP, 9.3 cm H2O vs. effective CPAP, 8 cm H2O (p < 0.0001). Comparing according to the degree of severity of the OSAHS, the average difference between calculated CPAP and effective CPAP was 0.24, 0.21, and 0.41 (non-significant differences) for mild, moderate and severe, up to an AHI < 40; in patients with an AHI ≥ 40 this difference was 1.10 (p < 0.01). We found an ac ceptable correlation between the calculated CPAP and the effective CPAP, with an intraclass correlation coefficient of 0.621, p < 0.01. Conclusion: We could use CPAP pressure prediction calculations to start treatment in patients with OSAHS who don't have access to self-adjusting therapies within the context of the pandemic, until standard calibration measures can be taken.

Factores subjetivos asociados a la no adherencia a la CPAP en pacientes con síndrome de apnea hipopnea de sueño / Subjective factors associated with cpap non-adherence in patients with sleep apnea hypopnea syndrome

Introducción: los beneficios de la CPAP dependen del número de horas que el paciente la use. El objetivo del estudio fue establecer, en pacientes con apnea del sueño (SAHS), si hay adecuada adherencia a la CPAP y determinar qué factores referidos por el paciente se relacionan a la no adherencia. Métodos: estudio observacional analítico transversal en pacientes tratados con CPAP. Se definió buena adherencia como uso mínimo de cuatro horas al menos el 70% de los días (registro del dispositivo). Análisis de regresión logística para evaluar los factores relacionados a la no adherencia: presión, resequedad de la vía aérea, problemas con la máscara y falta de educación en el uso de CPAP. Resultados: de 160 pacientes, 88 (55%) tuvieron mala adherencia. La edad, peso, talla, cuello e índice de apneas fueron similares en los grupos con buena y mala adherencia. El Epworth y la presión de CPAP fueron significativamente mayores en el grupo de mala adherencia (p<0.05). El promedio de horas de uso de CPAP en el grupo con buena adherencia fue de 5.1 ± 1.7 horas y en el grupo con mala adherencia fue de 1.9 ± 1.5 horas. Los pacientes sobreestimaron el uso de la CPAP en 2.0 horas: reportadas por el paciente 5.3 horas frente a 3.3 horas según la tarjeta del equipo (p<0.001). El único factor referido por el paciente que se relacionó con la mala adherencia fue la presión de CPAP (OR ajustado: 3,34 [1,34 a 8,30]). Conclusiones: la adherencia al tratamiento con CPAP en pacientes con SAHS es subóptima (mala adherencia en 55% de los pacientes). La principal causa relacionada con la no adherencia según los pacientes fue la intolerancia a la presión del dispositivo. Los pacientes sobreestiman las horas reales de uso del CPAP.

Introduction: the benefits of CPAP depend on the number of hours being used by the patient. The aim of the study was to establish, in patients with sleep apnea (SAHS), if there is adequate adherence to CPAP and to determine what factors reported by the patient are related to non-adherence. Methods: an analytical observational cross-sectional study in patients treated with CPAP. Good adherence was defined as a minimum of 4 hours use at least 70% of days (device score). Logistic regression analysis to assess factors related to non-adherence: pressure, airway dryness, mask problems and lack of education in the use of CPAP. Results: of 160 patients, 88 (55%) had poor adherence. Age, weight, height, neck and apnea index were similar in the groups with good and poor adherence. The Epworth and CPAP pressure were significantly higher in the group of poor adherence (p <.05). The average hours of use of CPAP in the group with good adherence was 5.1 ± 1.7 hours and the poor adherence group was 1.9 ± 1.5 hours. The patients overestimated the use of CPAP in 2.0 hours: 5.3 hours reported by the patient versus 3.3 hours according to the device card (p <0.001). The only factor reported by the patient that was associated with poor adherence was CPAP pressure (adjusted OR: 3.34 [1.34 to 8.30]). Conclusions: adherence to CPAP in patients with SAHS is suboptimal (poor adherence in 55% of patients). The main cause related to non-adherence according to patients was intolerance to the pressure device. Patients overestimate the real hours of CPAP use.