The Efficacy of an Oscillating Bed in the Prevention of Lower Respiratory Tract Infection: DISCUSSION part 2
Other studies warrant brief discussion for the sake of completeness. In a retrospective analysis of 123 patients with spinal cord injury, Reines and Harris found that respiratory complications (atelectasis and pneumonia) occurred during the first month of hospi-talization in 35.7 percent of patients. Among a sub-group of 20 patients treated with the RRKTT, however, the pulmonary complication rate was only 10 percent, suggesting that continuous postural oscillation was beneficial in this regard. Quite similar results were obtained in an earlier, smaller retrospective study of therapy with the RRKTT for spinal cord injury victims. Other studies, however, do not support the findings presented here. For example, Torrington et al reported that postoperative chest percussion and postural drainage failed to affect the incidence of postoperative pulmonary complications after gastric bypass surgery. It is not clear why intermittent chest physiotherapy is apparently less effective than treat¬ment with an oscillating bed, although the more sustained treatment afforded by the latter approach may be important. We can only speculate about the possible mecha-nisms that account for the observed beneficial effects of continuous postural oscillation. Experimental data support the idea that immobility leads to the formation of edema in dependent portions of the lung. Other data suggest that pulmonary edema impairs clearance of bacteria from the lung. Thus, continuous postural oscillation may work by improving clearance of bacteria from the tracheobronchial tree by ameliorating the tendency toward edema formation in dependent lung zones. Regardless of the mechanisms involved, our results suggest that the routine use of oscillating beds can decrease the incidence of pulmonary sepsis in patients with serious injuries due to blunt trauma. Since previous studies as well as our own data suggest that the risk of LRTI is especially high in victims of major head trauma, kinetic therapy may be particularly beneficial in this population of patients. This may be true also for very badly injured patients (ISS >=35), since the present data showed that this population had an increased likelihood of developing LRTI in the SICU.
Since bed choice was mandated by the study only while patients were in the SICU, a surprising result was the significant shortening of overall hospital LOS in the RRKTT group. Although a few patients that were randomized in the SICU to the study bed continued on the RRKTT after transfer to an acute care ward, this pattern was the exception rather than the rule. Therefore, one possible interpretation of our data is that early (but relatively short-term) therapy with an oscillating bed decreased the incidence of complications that tended to lengthen overall LOS in the hospital.
Although the cost of therapy with an oscillating bed is substantial, these costs seem to be largely mitigated by the apparent shortening of SICU and hospital stays. Indeed, a relatively crude analysis based on average costs (not charges) per day of care in the SICU indicated that total SICU costs (including costs asso¬ciated with renting the RRKTT) were similar for patients randomized to a conventional or oscillating bed (median hospital costs: $4,280 and $3,325, re-spectively; p = 0.362 by Mann-Whitney U test). suhagra 100
In summary, we showed that therapy with an oscillating bed significantly lessens the risk of LRTI and pneumonia and significantly shortens hospital stay in critically ill victims of nonpenetrating trauma. Our results may not be generalizable to other institutions because of variations in orthopedic management (eg, early vs delayed operative fixation) or standard nursing care. Nevertheless, the findings in this study are consistent with results from other randomized pro¬spective trials suggesting that continuous postural oscillation may have a valid role in the care of certain high-risk patients with impaired mobility.
