239
7. Fuller RW,Dixon CMS, Cuss FMC, Barnes PJ. Bradykinin-induced bronchoconstriction in man: mode of action. Am RevRespir Dis 1987; 135:176-80. 8. Dixon CMS, Barnes PJ. Bradykinin-induced bronchoconstriction: inhibition by nedocromil sodium and sodium cromoglycate. Br J Clin Pharmacol 1989; 27:831-6. 9. Mak JCW, Barnes PJ. Autoradiographic visualization of bradykinin receptors in human and guinea pig lung. Eur J Pharmacoll991; 194:37-44.
EQUIPMENT FAILURE WITH NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE
To the Editor: This letter describes two items of information relevant to equipmentrelated problems of compliance with the nasal continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea syndrome. Nasal CPAP has been shown to be a safe and effective long-term therapy in many patients (1-3). In order to continue to be effective, it appears that most patients have to use this device on a regular basis. Identified determinants for continued medical benefit are the severity of the disease, physician enthusiasm for the treatment, and, most importantly, patient willingness to try the therapy. Relatively little attention has been paid to equipmentrelated problems, failure, or inadequate maintenance of CPAP equipment and its impact on clinical therapy. 1\\'0 recent events here have illustrated to us the importance of this. First, we recently reviewed the outpatient sleep apnea program at the Veterans Administration Medical Center, Cleveland, Ohio, from 1986 to 1990. There were 125 patient-initiated, walk-in visits by 55 patients for concerns about their nasal CPAP equipment. This time frame represented approximately 1,()()() treatment months. During this time, there were 11 machine malfunctions, requiring repair (n = 10) or replacement. The other problems (n = 114) included mask replacement (42070), filter cleaning or replacement (20070), headgear replacement or modification (13070), breakage of the Sanders circuit (12070), valvemalfunction (9070), and other replaceable items (5070). Second, we participated in a patient support group dedicated to improving patient information and community awareness of sleep apnea. In a recent meeting, there was demonstration of new equipment and an opportunity for patients to "check out their machines." Eighteen patients, some of whom had purchased their equipment outright, brought their CPAP equipment. We found three major problems with the equipment of which the patients (n = 3) were unaware. One patient had an absence of an expiratory valve on the
machine, resulting in a recent inability to use the machine over the past month. 1\vo other patients had masks that wereno longer functional because hardening of the mask caused either leaks or poor fit. Patients had not recognized these problems, although all had reported recent symptom exacerbation. These three problems were solved on site and wereindependent of the three home-care companies present. The response of home-care companies and patients to this sort of session was positive. Our conclusion is that outpatient nasal CPAP therapy requires close attention to nasal CPAP equipment. Not only physicians, but also patients in cooperation with their home-care companies should be actively involved in long-term maintenance of nasal CPAP. Patient information groups can be useful in the identification of problems with nasal CPAP, which can then be addressed by physicians and the home-care companies. All three groups should work together to facilitate and improve long-term home care using this treatment modality. BARBARA G
7. Fuller RW,Dixon CMS, Cuss FMC, Barnes PJ. Bradykinin-induced bronchoconstriction in man: mode of action. Am RevRespir Dis 1987; 135:176-80. 8. Dixon CMS, Barnes PJ. Bradykinin-induced bronchoconstriction: inhibition by nedocromil sodium and sodium cromoglycate. Br J Clin Pharmacol 1989; 27:831-6. 9. Mak JCW, Barnes PJ. Autoradiographic visualization of bradykinin receptors in human and guinea pig lung. Eur J Pharmacoll991; 194:37-44.
EQUIPMENT FAILURE WITH NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE
To the Editor: This letter describes two items of information relevant to equipmentrelated problems of compliance with the nasal continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea syndrome. Nasal CPAP has been shown to be a safe and effective long-term therapy in many patients (1-3). In order to continue to be effective, it appears that most patients have to use this device on a regular basis. Identified determinants for continued medical benefit are the severity of the disease, physician enthusiasm for the treatment, and, most importantly, patient willingness to try the therapy. Relatively little attention has been paid to equipmentrelated problems, failure, or inadequate maintenance of CPAP equipment and its impact on clinical therapy. 1\\'0 recent events here have illustrated to us the importance of this. First, we recently reviewed the outpatient sleep apnea program at the Veterans Administration Medical Center, Cleveland, Ohio, from 1986 to 1990. There were 125 patient-initiated, walk-in visits by 55 patients for concerns about their nasal CPAP equipment. This time frame represented approximately 1,()()() treatment months. During this time, there were 11 machine malfunctions, requiring repair (n = 10) or replacement. The other problems (n = 114) included mask replacement (42070), filter cleaning or replacement (20070), headgear replacement or modification (13070), breakage of the Sanders circuit (12070), valvemalfunction (9070), and other replaceable items (5070). Second, we participated in a patient support group dedicated to improving patient information and community awareness of sleep apnea. In a recent meeting, there was demonstration of new equipment and an opportunity for patients to "check out their machines." Eighteen patients, some of whom had purchased their equipment outright, brought their CPAP equipment. We found three major problems with the equipment of which the patients (n = 3) were unaware. One patient had an absence of an expiratory valve on the
machine, resulting in a recent inability to use the machine over the past month. 1\vo other patients had masks that wereno longer functional because hardening of the mask caused either leaks or poor fit. Patients had not recognized these problems, although all had reported recent symptom exacerbation. These three problems were solved on site and wereindependent of the three home-care companies present. The response of home-care companies and patients to this sort of session was positive. Our conclusion is that outpatient nasal CPAP therapy requires close attention to nasal CPAP equipment. Not only physicians, but also patients in cooperation with their home-care companies should be actively involved in long-term maintenance of nasal CPAP. Patient information groups can be useful in the identification of problems with nasal CPAP, which can then be addressed by physicians and the home-care companies. All three groups should work together to facilitate and improve long-term home care using this treatment modality. BARBARA G
