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Is Nasal Cannula a Viable Treatment for Sleep Apnea?
Johns Hopkins University researchers report that patients with obstructive sleep apnea and hypopnea can significantly reduce symptoms through nasal insufflation (TNI) treatment, which uses a nasal cannula to deliver warm, humidified air at a high flow rate.
"Our findings provide evidence that TNI may offer a viable treatment alternative to patients with obstructive hypopneas and apneas," said lead researcher Dr. Hartmut Schneider, of Johns Hopkins Asthma and Allergy Center.
The proof of concept study included 11 patients with mild to severe apnea-hypopnea disorders, who were selected to provide a balanced range of disease severity. Apnea was defined as complete cessation of airflow for more than 10 seconds. Hypopnea was a reduction of airflow defined as greater than 30 percent.
At TNI of 10 L/minute, some indications of disordered breathing showed improvement, but airflow limitations and snoring persisted. However, at TNI of 20 L/minute, all patients showed a marked improvement. "When TNI was administered, sleep and breathing patterns stabilized," said Schneider.
The results also showed that even patients with more severe disorders gained significantly from TNI. These findings suggest that TNI may be a more viable treatment option for patients with hypopnea and sleep apnea.
"At present, CPAP is most effective at eliminating apneas and hypopneas, (but) long-term effectiveness is compromised by low adherence," wrote the researchers. "We developed a simplified method for increasing pharyngeal pressure by delivering warm and humidified air at a continuous high flow rate through the open nasal cannula."
While patients with severe sleep apnea may be more highly motivated to adhere to treatment with CPAP or surgery, younger, thinner and healthier patients with milder disorders may find the TNI approach appealing, according to Dr. Safwan Badr, chief of pulmonary, critical care and sleep medicine at Haper University Hospital in Detroit and chair of the American Thoracic Society's Assembly on Respiratory Neurobiology and Sleep.
The authors noted that the minimally intrusive nasal interface of TNI may improve patient adherence, and may ultimately prove more effective at managing long-term morbidity and mortality of sleep apnea. The fact that one flow rate and one cannula size were sufficient to stabilize breathing patterns in the majority of subjects suggests that titration of TNI may be unnecessary, streamlining the initiation of treatment.
The present study is a proof of concept, the authors wrote, and will require replication in clinical trials. However, the study represents the first step in developing a new potential alternative to current sleep apnea treatments that may lower the barrier for care in patients with sleep-associated breathing disorders.
The research was reported in the second issue for July 2007 of the American Journal of Respiratory and Critical Care Medicine published by the American Thoracic Society.
