2006 OPEN FORUM Abstracts
A COMPARISON OF POSITIVE AIRWAY PRESSURE AND VOLUME EXPANSION THERAPY IN THE PREVENTION AND TREATMENT OF ATELECTASIS IN THORACIC AND ABDOMINAL SURGERY PATIENTS
- David
Mussetter, BA, RRT, Tim Frymyer, BS, RRT, Mike Trevino, MS, RRT, Gary Weinstein,
MD, FCCP, Presbyterian Hospital of Dallas, Dallas, Texas
Background: Our
hospital is a 903-bed acute care teaching facility in a major metropolitan
area. Our respiratory therapy department works under a protocol driven clinical
practice model whereby the therapist evaluates, orders, modifies, and
discontinues therapy. Upon reviewing the body of literature contrasting
positive airway pressure therapy with volume expansion therapy, we determined
there was sufficient evidence to warrant a change in our treatment for the
prevention and reversal of atelectasis. This change was made to the group of
patients felt to be at high risk. We now seek to discern what significance this
change in treatment methodology has made.
Method: All
patient data was collected retrospectively. Patients were randomly selected
from a three month period, two to four months before the introduction of
positive expiratory pressure (PEP) and intermittent use of continuous positive
airway pressure (iCPAP). This first group of patients
received incentive spirometry (IS) and/or intermittent positive pressure
breathing (IPPB) per our respiratory therapy protocol. A second group of
patients was randomly selected from a three month period, four to six months
after the initiation of PEP and/or iCPAP. Each
patient in both groups underwent thoracic or non-laparoscopic abdominal surgery.
There were 18 patients excluded due to: A) no comparison data for CXR or
oxygenation [5], B) no respiratory therapy treatment within 24 hours of
extubation [1], C) requiring > 24 hours of mechanical ventilation
post-operatively [9], D) experiencing more than one surgery during their stay
[2], or E) not being initially admitted for surgery [1]. Patient data collected
include age, sex, obesity, smoking status, anesthesia type and length, post-operative
ventilatory status, occurrence of pre-operative
instruction, pain management, length of stay (LOS), expected LOS, DRG
designation, ambulation, CXR results, oximetry, and number and type of
treatments received.
Results: The two
patient populations were demographically well correlated (0.994) and LOS did
not differ significantly. Other clinical outcome criteria presented as follows:
| IS / IPPB Group n = 41 | PEP / iCPAP Group n = 39 | |
| CXR deterioration POD 0 - discharge | 46% n = 35 | 3% n = 31 |
| CXR deterioration POD 0 - 1 | 31% n = 29 | 3% n = 29 |
| CXR deterioration POD 1 - discharge | 22% n = 27 | 0% n = 26 |
| SaO2 decline from baseline post-op SaO2 to POD 1 | 38% n = 37 | 26% n = 38 |
| SaO2 decline from baseline post-op SaO2 to POD 2 | 36% n = 28 | 31% n = 35 |
| SaO2 decline from baseline post-op SaO2 to POD 3 | 47% n = 19 | 35% n = 31 |
In addition, it has been empirically reported that patients
experienced less pain using PEP versus IS or IPPB, leading to improved
compliance.
Conclusion: PEP and/or
iCPAP seems to demonstrate an objective improvement over
IS and/or IPPB when comparing CXR and SaO2 data. Whether these
results are statistically or clinically significant is not yet clear given the
small sample size. Despite this, the early data points favorably towards the
utilization of PEP and/or iCPAP. If this holds true,
benefits might also be derived from patients having a higher compliance rate
with the less painful (assumed) PEP therapy. Further study may provide more definitive
answers.