2004 OPEN FORUM Abstracts
UTILIZATION OF THE HiOX™ MASK FOR DELIVERING INHALED NITRIC OXIDE
Renaghan RRT • John E. Hahesy MS, RRT,CPFT
Care Services • Stanford Hospital & Clinics •
Introduction: Inhaled nitric oxide (INO) is recognized as a potent agent for demonstrating pulmonary vasoreactivity in the cardiac catheterization laboratory. Patient response to INO, from both primary and secondary causes, provides prognostic and predictive response to other pulmonary vasodilators for long-term therapy. At our institution, INO is safely and effectively delivered by mask with the INOvent™ (INOTherapeutics Corporation) to adult patients with the configuration shown in figure 1. We evaluated the HiOX™ mask (Viasys) as a simplified alternative to the established configuration for the noninvasive delivery of INO.
Methods: A volunteer subject received INO via the standard mask system (fig. 1) and the HiOX™ mask. The comparative efficacy of the two delivery systems was determined by sampling at the mask interface to determine INO response time (from set to measured), nitrogen dioxide (NO2) accumulation, and FiO2 stabilization (determined by the maximum FiO2 delivered with a set FiO2 of 1.00). Sampling was compared at: 1). INO @ 5ppm with FiO2 = 0.21, 2). INO @ 5ppm with FiO2 = 1.00, 3). INO @ 20ppm with FiO2 = 0.21, 4). INO @ 20ppm with FiO2 = 1.00.
Results: Table 1 lists the comparative response times (from set to measured) between the two mask systems.
|Table 1.||5ppm @ 0.21||5ppm @ 1.00||20ppm @ 0.21||20ppm @ 1.00|
|Standard mask||60 seconds||60 seconds||60 seconds||60 seconds|
|HiOX™ mask||30 seconds||30 seconds||30 seconds||30 seconds|
NO2 accumulation at all settings corresponded to 0.2ppm
with the standard mask system, and 0.1ppm with the HiOX™
mask system. Comparative FiO2 stabilization at 1.00
produced a maximum FiO2 of 0.93 with the standard mask
system, and 0.97 with the HiOX™
Conclusions: The HiOX™ mask provided a comparatively faster INO response time, lower NO2 accumulation, higher FiO2 stabilization, and offers practical advantages secondary to lower total flow requirements and a simplified configuration. In vivo utilization will determine anticipated improvement in patient comfort and compliance.