In addition, the peak airway pressure recorded on the pressure monitor of the respirator was clearly higher in the “failure-obstructive” group than in the “success-restrictive” group (33 ±4 vs 22 ±6 cm H20, respectively) (p<0.05; unpaired f-test).
In Table 4, it can be seen not only that the number of days during which NPPV could be performed was higher in the “restrictive-success” group than in the “obstructive-failure” group, but also that the daily duration of NPPV and, consequently, the total duration of this procedure were very different (ie, longer) in the “success-restrictive” group of patients. When we measured the amount of time spent by the nurses with their patients submitted to NPPV, it was obvious that in patients in the “obstructive-failure” group, NPPV was far more time-consuming for the health-care team than in patients in the “restrictive-success” group; one nurse had to stay close to the bedside around 40 percent of the duration of the NPPV in patients in the “restrictive-success” group, whereas this time rose to more than 90 percent in “obstructive-failure” situations (p<0.002; unpaired f-test) (Fig 3).
Finally, longer sessions of NPPV could be performed in the “restrictive-success” group than in the “obstructive-failure” group of patients (180 ±30 vs 21 ±17 minutes) for the duration of one session (p<0.03; unpaired f-test). Furthermore, there was a clear trend in the “restrictive-success” group toward a rapid increase of the duration of one NPPV session after the first 2 to 3 h of the procedure, whereas the duration of a session remained desperately short (ie, <30 minutes) in the “obstructive-failure” group.
Table 4—Course of NPFV and Nurses9 Involvement with Patients with Restrictive vs Obstructive Disease
|Group||Duration of NPPV||Nurses’ Work percent of NPPV Time|
|Days||Hours per 24 Hours||Total Hours|
|Mean±SD||13±5t||10 ±2||135 ±80||41 ±9|
|Mean±SD||5±5t||5±1||21 ±23||91 ±95|
Figure 3. Total duration of NPPV (black columns) and total duration of nurses’ work in hours (hatched columns) in all patients (patients 1 to 6).