The Science Journal of the American Association for Respiratory Care

2000 OPEN FORUM Abstracts


F. Herbert Douce, MS, RRT; Irina Wyatt, CRT; The Ohio State University, Columbus, Ohio

Background: Educational programs are challenged to provide learning experiences for the ever-expanding scope of practice of respiratory care, including a growing plethora of modes of mechanical ventilation for our adult patients. Some modes may have limited application and are available on only one brand of ventilator. The purpose of this study was to determine which ventilator modes should be highest priority for curriculum and credentialing for respiratory care.

Methods: We developed a 16 item questionnaire with 13 modes of mechanical ventilation identified in common textbooks and asked for the frequency of their use using a 5-point Likert-type scale. The 13 modes are: volume control mechanical ventilation (VCMV), pressure control mechanical ventilation (PCMV), pressure control inverse ratio ventilation (PCIRV), assist control (AC), intermittent mandatory ventilation (IMV), synchronized intermittent mandatory ventilation (SIMV), continuous positive airway pressure (CPAP), pressure support ventilation (PSV), proportional assist ventilation (PAV), airway pressure release ventilation (APRV), mandatory minute ventilation (MMV), volume assured pressure support (VAPS), pressure regulated volume control (PRVC). We defined the scale as: 1-very often (i.e. daily), 2-often (i.e. more than once a week), 3-sometimes (i.e. less than once a week), 4-rarely (i.e. less than once a month), 5-never. The demographic items were number of ventilator-beds, and county where the hospital is located. Of the 199 acute-care hospitals in Ohio, we randomly selected and surveyed 100. We mailed cover letter, questionnaire and an addressed, postage-paid return envelope and collected data for 30 days. We tabulated and described responses for all respondents, and based upon their county location, we separated hospitals as metropolitan or rural, and based upon the number of ventilator beds as small (1-10 ventilator beds), medium (11-20 ventilator-beds), or large (21 or greater). Using SPSS 9.0, we compared means using one way analysis of variances with repeated measures and Tukey's post-hoc comparison to identify critical differences between frequencies for different modes of the mechanical ventilation. To consider modes used in different locations and sizes of the hospitals we computed chi square using Scheffe's method.

Results: Fifty-five (55%) hospitals responded. The distribution of respondents reflects the distribution of hospitals in Ohio for location and size and is presented in Table 1. For all respondents, 5 modes were reported as used

Rural Metropolitan Small Medium Large
28 (51%) 26 (49%) 18 (33%) 17 (31%) 20 (36%)

often and very often, 2 modes were used sometimes, and 6 modes were rarely or never used. There was no statistically significant difference in the use of any of the 13 modes of mechanical ventilation between rural and metropolitan hospitals. However, there were significant differences for 5 out of 13 modes for hospitals based upon number of ventilator beds with AC, SIMV, PSV, and CPAP being used less often in smaller units (p<0.01) and PCIRV being used more frequently in larger units (p<0.01). Conclusion: Some adult modes of mechanical ventilation are rarely, if ever used. Given limited instructional and clinical time, educational programs should concentrate on the most often used 7 modes. To assess expected competence for adult mechanical ventilation, credentialing examinations should include the 7 most often used modes. Children's hospitals and modes of neonatal ventilation were not considered.; otherwise the respondents reflect hospitals nationwide.