Algorithm Based CPAP Titration Formulas: A Comparison and Review

Mathematical Equations to Predict Positive Airway Pressures for Obstructive Sleep Apnea: A Systematic Review

“…Rowley et al's study [ 43 ] increased the success rate of titration protocols from 50 to 68% (AHI decreased by 50% and a final AHI ≤10 events/hr at final tested pressure). Seven studies used the mathematical equation in order to derive a starting PAP titration pressure; thereby the technicians would start at a pressure that was closer to the actual therapeutic pressure [ 15 , 35 , 38 , 45 , 48 , 58 , 59 ].…”

“…The Epworth Sleepiness Scale Score was a variable in the study by Lee et al [ 31 ]. When comparing the eleven studies in our review that utilized neck circumference for derivation of the mathematical equations [ 15 , 28 , 35 , 38 , 43 , 45 , 48 , 58 – 61 ], seven of these successfully predicted therapeutic PAP. The coefficient for neck circumference ranged between 0.01 and 0.16.…”

“…A patient who has a significant proportion of REM sleep may end up needing a higher amount of pressure secondary to the upper airway relaxation. Thus far, only Tofts et al [ 58 ] have evaluated the effect of AHI during REM; however, the AHI during NREM was not evaluated as a separate variable; rather the AHI in its entirety was included in the formula. A second area of research is whether the pressure requirements are really correlated with apnea-hypopnea index as a whole, or it may be that apneas and hypopneas should have different coefficients as it is logical that an apnea would require higher pressures than a hypopnea to maintain a patent airway.…”

“…A second area of research is whether the pressure requirements are really correlated with apnea-hypopnea index as a whole, or it may be that apneas and hypopneas should have different coefficients as it is logical that an apnea would require higher pressures than a hypopnea to maintain a patent airway. Only, Tofts et al [ 58 ] have evaluated the effect of hypopnea as a variable, but the apneas were not included as variable in their mathematical equation. The contribution that hypopneas versus apneas can make is difficult to answer, as two different patients with the same AHI but a different proportion of apneas and hypopneas might require different pressures to overcome these obstructive events, thus potentially making mathematical equations that do not separate the two variables less accurate.…”

Avaliação polissonográfica do tratamento da síndrome da apneia obstrutiva do sono com pressão fixa de CPAP determinada por fórmula

“…No ano seguinte, West, Jones e Stradling (2006), com a argumentação de que não havia nenhum estudo de longo prazo (mais de 12 semanas) para comparar diretamente os diferentes métodos de início de CPAP, realizaram um estudo prospectivo randomizado, cujos desfechos primários foram a avaliação da sonolência subjetiva e objetiva, pressão arterial de 24 horas, auto-relato do estado de saúde, adesão ao CPAP e o desfecho secundário foi determinar as diferenças nas pressões médias de CPAP administradas entre os três grupos.…”