2006 OPEN FORUM Abstracts
THE BENEFITS OF USING THE OPEN LUNG TOOL (OLT) WITH THE DIFFICULT TO OXYGENATE PATIENTS AS A LUNG RECRUITMENT MANUEVER AND AS A GUIDE TO SET OPTIMAL PEEP LEVELS
Suzana Ristoski RRT BBA MBA,
Educator-Respiratory Care Department, Dr. Stephen Galens MD. Medical Director.
William Beaumont Hospital, Troy, 44201 Dequindre Rd., Troy, MI 48085
Background: The OLT is an option on
the Maquet Servo i ventilator. The
OLT was available to the respiratory care staff, however initially rarely ever utilized
secondary to the lack of knowledge and fear of the unknown. Initially, when the
OLT was utilized and completed, Pressure Control (PC) was the ending mode of
ventilation used, showing no significant improvement. In order to utilize this
lung recruitment maneuver option effectively a trial protocol evaluation was
performed. As a result of the positive findings of the observation and the data
collection, a new protocol was developed. Certain criteria needed to be present
in order to initiate the OLT. The initial criteria included a sustained FiO2
≥ 50% and a PEEP level of ≥ 8 cmH2O. These patients often presented
with ARDS or severe pneumonia. The time period for the trial was August 2005
through December 2005. Seven adult patients (pts) qualified for the OLT. These
pts had the OLT performed and were closely observed and data was collected.
Method: During the time frame of the
trial, all pts that qualified for the OLT received an initial order from a pulmonologist
to perform the OLT. The maneuver was performed by the respiratory therapist.
Prior to starting the OLT: 1) the pt should be hemodynmically stable, 2) pt may
have some sedation if agitated or has an increased RR, 3) therapist must
suction pt; calculate ideal body weight for target tidal volume; observe
initial dynamic compliance and mean airway pressure (MAP); and adjust alarms.
General application of the OLT: 1) increase PEEP gradually to 20cmH2O, 2)
increase PC to 30 cmH2O (PIP of 50cmH2O) -hold for 2 min, 3) decrease PC to
target tidal volume, 4) decrease PEEP to closing critical pressure- add 2cmH2O
to that pressure for optimal PEEP, 5) re-recruit the lung by returning the PIP
to 50 cmH2O-hold for 2 min, 6) decrease PC to achieve the target tidal volume.
After the OLT was performed the therapist had the autonomy to set ventilator
settings according to what the OLT presented. The pt was set on BiVent unless
otherwise ordered by the physician. ABGs were collected 1 hr after the OLT.
Pt's dynamic compliance, ABG results, and hemodynamics were closely monitored.
The OLT would be repeated every 8 hours (and as needed if pt deteriates) for
the first 24 hrs. After the 24 hrs, pt was reassessed for the need of the OLT.
As pt progresses they were weaned with the BiVent settings. BiVent was made the
standard mode of ventilation for the protocol when the OLT is completed.
Results: The ABG results of six out of
the seven pts showed significant changes in PaO2 shown in Table 1. However
there is one patient where the PaO2 decreased after the OLT- that patient was
terminally weaned that day. Results showed that the ARDS patients showed a greater
improvement in PaO2 compared to the severe pneumonia patients. Percent changes
in PaO2 before and after, ranged from 366% to -28%. In addition, the BiVent
mode showed better results compared to the use of PC observed prior to the
protocol trial evaluation.
Table 1:
PaO2 comparison before and after OLT maneuver
| Patient | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| PaO2 Before OLT | 88 | 62 | 65 | 63 | 89 | 92 | 61 |
| PaO2 After OLT | 218 | 97 | 303 | 75 | 148 | 66 | 171 |
| % change post 1hr | 147% | 56% | 366% | 19% | 66% | -28% | 180% |
Conclusion: The
OLT maneuver is utilized as a lung recruitment maneuver and for a guide to set
the optimal PEEP and pressures to achieve the target tidal volume. It shows a
significant improvement in oxygenation on hard to oxygenate pts. The study
found that it is more effective with ARDS pts rather than with severe pneumonia
pts, however improvements are still observed with the pneumonia pts. In
addition, as lung mechanics change, vent settings must change as well.
Our
OLT protocol gives the therapist the autonomy to change ventilator settings
according to optimal settings that we have observed from the OLT maneuver.