Nasal Positive Pressure Ventilation in Patients with Acute Respiratory Failure (15)
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).