2003 OPEN FORUM Abstracts
USE OF THE SENSORMEDICS 3100B HIGH FREQUENCY OSCILLATOR RESULTS IN IMPROVED OXYGENATION INDEX AT 24 HOURS AFTER DEVICE INITIATION
Russell T. Reid, BBA, RCP, RRT, CPFT Tom Nelson, RCP, RRT Carolinas
Medical Center, Charlotte, NC
Background: The introduction of a device designed specifically for high frequency oscillatory ventilation (HFOV) of patients weighing greater than 35 kilograms offers an alternative to "conventional" modes of mechanical ventilation for larger patients experiencing clinically significant oxygenation deficits in addition to other clinical indications.
Method: Twelve medical and surgical patients who were deemed to be failing "conventional" ventilation by the attending physician were placed on HFOV. Values for conventional ventilation settings and ABGs were obtained prior to placing the patient on HFOV. Values for the high frequency oscillator settings and ABGs were obtained after initiation of HFOV and again 24 hours after the initiation of HFOV. Oxygen Index (OI) was calculated for each patient using the formula OI = (MAP x FIO2)/PaO2. The data was collected retrospectively.
RESULTS: Data was collected for twelve patients (8 males and 4 females) that had been receiving "conventional" ventilation for 9.9 (+ 15.4) days prior to implementation of HFOV. The average patient age was 21.1 (+ 13.0) years with an average weight of 61.5 (+ 32.9) kg. The OI for patients receiving HFOV for 24 hours versus "conventional" ventilation was significantly reduced (p = 0.016), with OI values of 21.1 (+ 13.0) vs. 30.7 (+ 15.6), respectively. Statistical comparison was made using the Student T-test. Ventilation and acid-base values, after receiving HFOV for 24 hours, were not significantly different from conventional ventilation. The average PaCO2 was 38.8 (+ 6.4), p.H. 7.39 (+ 0.08) and Base Excess -0.8 (+ 4.7) compared with pre-HFOV values of 39.0 (+ 10.5), p.H. 7.39 (+ 0.1) and Base Excess -0.3 (+ 5.3). The initial HFOV settings and the settings at 24 hours are shown in Table 1.
|n||MAP cm H2O||FIO2 %||Power/Delta P||Bias Flow||% I.time||Hz|
|Initial HFOV Settings||12||35.2 (+ 4.0)||90.8 (+ 18.8)||5.8 (+ 0.5)/ 68.3 (+10.1)||30.0 (+ 2.1)||36.0 (+ 6.6)||4.9 (+ 0.5)|
|24 Hr HFOV Settings||12||34.4 (+ 3.3)||52.9 (+ 23.9)||5.8 (+ 1.0)/ 66.6 (+12.0)||29.6 (+ 3.3)||39.2 (+ 8.2)||4.8 (+ 0.9)|
Table 1. Initial Patient HFOV Settings and HFOV Settings at 24 Hours
Experience: The authors have been involved in the initiation and management of HFOV as well training other individuals to use this ventilatory modality.
Conclusions: The use of HFOV results in a significant improvement in OI at 24 hours after placement of the patient on HFOV. The improvement in OI is primarily a result of a decreased FIO2 requirement to maintain acceptable patient oxygenation while using HFOV.