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Comparison of Function of Commercially Available Pleural Drainage Units and Catheters: Conclusion

All other PDU models demonstrated significant pressure accuracy error differences between the two external suction settings (manufacturer-suggested wall suction setting vs full wall suction) in the negative direction (delivering more negative pressure than the PDU test value). The least accurate PDU at full wall suction was the Thora-Seal III, with a mean error of 27%. This translates to a mean delivered negative water pressure of 25.4 cm H2O. Similarly, the most inaccurate PDU with a — 40 cm H2O setting when tested at full vacuum, the Atrium 3612, produced a mean error of 2.9% in the negative direction (a mean delivered negative pressure of — 41.2 cm H2O). Such minimal increases in negative pressure are likely of little clinical consequence. website
No definitive comparison in the accuracy (Table 3) of the water column PDU vs dry PDU systems can be made (Table 1). Absolute mean accuracy (positive or negative error) of the water column units when tested at a set pressure of — 20 cm H2O varied from a mean error of 0.0% (Sentinel Seal) to 4.6% (Atrium Ocean 2002). The dry unit absolute mean accuracy when tested at — 20 cm H2O varied from 4.2% (Pleur-evac A-6000) to 15.5% error (Atrium 3612).
Several problems exist with this study of PDUs and PDCs. First, although major US manufacturers were contacted, not all commercially available devices were tested. For example, the TRU-CLOSE Thoracic Vent Procedure Tray (Davis and Geck; Wayne, NJ), a PDC, was not tested due to the inability to adapt the device to our testing system. Larger-bore chest tubes, except the Cook C-TQTS-2400, were not tested given that clinically significant potential flow restrictions were found to exist primarily with small-bore catheters. Products not available in the United States were not tested. Addition ally, as product lines evolve, the devices reported in this study may no longer be available or be modified and carry the same or different name. Accordingly, the same name may not equate to the same flow and/or accuracy characteristics. This requires the clinician to always query the maximal flow rates that a PDU or PDC delivers and the accuracy of a PDU when incorporating new products in their practice. Lastly, our sham set-up was designed to assess optimal flows from each PDU and PDC, and the PDU accuracy of delivered pressures. This design, however, may not reflect clinical conditions, particularly for a PDC, wherein the pleural space and its non-air contents may affect the flow a particular device may be capable of handling. The presence of the lung or pleural debris such as blood may significantly decrease the air flows reported from our test design.
In conclusion, multiple different flow rates are noted among different PDUs at the same negative water pressure settings. Although significant accuracy differences in delivered pressures of the PDU tested are seen, these may not be of clinical consequence. PDUs, in general, significantly protect the patient (pleural space) in the event of inadvertent use of full wall suction. Similarly, multiple significant differences in PDC flow rates exist, including between catheters of the same bore size. The significant differences in accommodated air flows may be particularly important in patients with large air leaks. Incorporation of such knowledge may preclude the development of a tension pneumothorax.