2009 OPEN FORUM Abstracts
SOLUTION OUTPUT OF A LARGE VOLUME NEBULIZER DURING CONTINUOS ALBUTEROL NEBULIZATION: IN-VIVO VS. IN-VITRO STUDY
Randy Willis1, Ariel Berlinski2,3; 1RCS, Arkansas Childrens Hospital, Little Rock, AR; 2Dept of Pediatrics, UAMS, Little Rock, AR; 3Pediatric Aerosol Research Laboratory, ACHRI, Little Rock, AR
Background: The use of continuous albuterol nebulization using a large volume nebulizer (LVN) is a common practice in the treatment of status asthmaticus. Predictable aerosol delivery is paramount to treat these patients. Real life performance of delivery devices might vary from laboratory evaluation performed under optimal conditions. In this study we compared the solution output of an LVN during in-vitro and in-vivo conditions. Methods: 50 LVNs (HOPE Nebulizer, B&B Medical Technologies, Carlsbad, CA) used by patients in the PICU were studied. The LVNs were operated at 10 Lpm as per manufacturer recommendations. The nebulizer was connected to a 6 feet corrugated tubing. Loading volume was 200 mls (prescribed albuterol dose + saline solution). There was no intervention by the research team. The fluid level was checked and the time of the observation and fluid level were marked at the beginning and at around the 2nd, 4th and 6th hours of operation. Once the treatments were completed the LVNs were weighted dry and with saline solution up to each of the previously made marks. Solution output (SO) was then calculated by the gravimetric method (PATNEB). A separate set of 4 LVNs were run under similar conditions in the laboratory and the output was measured by same technique (LABNEB). SO was expressed as ml/2hours of operation. Analysis of variance (ANOVA) and ANOVA for repeated measures followed by multiple comparison analysis Tukey when necessary were used to compare between conditions and within nebulizers respectively. A p < 0.05 was considered statistically significant. The study was approved by UAMS IRB. Results: 40 and 6 nebulizers had data for the first 6 and 4 hours respectively. 4 nebulizers had prolonged intervals between observations and were not included. Patient characteristics were (mean, CI95%): 65% female, age; 6.3 years, 5 â7.6 years; weight 27.1 kg, 21.8 â 32.4 kg. Albuterol dose was 0.5 and 1 mg/kg/hour for 37% and 63% of the patients respectively. SO (ml/2hours, mean Â± SD) for PATNEB was 45.5 Â± 10, 43.6 Â± 12.2 and 40.7 Â± 8.1 at 2nd, 4th and 6th hour respectively (p = 0.11). SO (ml/2hours) for LABNEB was 40.6 Â±1.7; 41.3 Â±2.5 and 42.7 Â± 3.4 at 2nd, 4th and 6th hour respectively (p = 0.86). No differences in SO between PATNEB and LABNEB were noted (p = 0.33, 0.71 and 0.64 for the 2nd, 4th and 6th hour respectively). Conclusions: This large volume nebulizer showed similar solution outputs both in a laboratory and real life settings Sponsored Research - The study was partially supported by an unrestricted educational grant from S&T Medical Technologies, Inc.