2005 OPEN FORUM Abstracts
HYDROPHOBIC FILTER RETAINS MICROBIAL BARRIER CHARACTERISTICS WHEN USED WITH HEATED HUMIDIFIER FOR CPAP IN SLEEP APNEA
GA Ortolano PhD, J Schaffer DVM, MB McAlister PhD, FP Canonica PhD,F Satti MD*, JS Cervia MDPall Corporation, East Hills, NY and *Long Island Jewish Hospital, New Hyde Park, NY
BACKGROUND: Sleep apnea is treated with continuous positive airway pressure (CPAP), however poor compliance may result from airway dessication discomfort that heated humidification can diminish. But tap water in humidifiers may contain pathogens and pose a risk for respiratory infections prompting characterization of the performance of a filter with CPAP humidifiers.
METHODS: Pall BB50T filters were subjected to maximum air flow from a HumidAire 2i (ResMed San Diego, CA) for 10 hrs daily over 1, 4 and 7 days using CPAP (ResMed AutoSet Spirit). Removed filters were subjected to either B. diminuta or MS-2 bacteriophage challenge (10(8) CFU or PFU, respectively).
RESULTS: B. diminuta added to humidifier water was recoverable in the breathing tube in the absence of a filter. Microbial retention did not differ from unused filters following 1,4 and 7 days of humidification averaging 99.997+0.003% for B. diminuta and 99.995+0.002% for MS-2 bacteriophage (ANOVA P> 0.05). Air flow rates decreased only 4% over time. Insignificant pressure drop (ANOVA P> 0.05) averaged 1.10+0.12 cm water.
CONCLUSION: Tap water used in CPAP humidifiers may represent an underappreciated source of respiratory pathogens during the treatment of sleep apnea. A properly positioned filter does not obstruct air flow and can maintain microbial barrier protection.