The use of portable, single patient use, closed wound suction devices to drain surgical wounds is increasing in surgical practice. The closed wound suction device includes a suction inducing reservoir where the suction is applied to the patient's surgical wound via a connector tubing with a distal tip placed in the wound site to be drained. An air tight seal is created at the point the tubing exits through the skin to provide a "closed wound" so that suction drainage is effective in removing wound exudate and other unwanted material from the wound site. Sometimes the wounds are contaminated and sometimes the wounds are clean and uncontaminated. The reservoir collects the exudate sucked from the wound via the tubing until the reservoir is ready to be emptied, or until such time or at such time intervals as directed by the physician. The container reservoir generally fills in a matter of hours and is then emptied. When the reservoir does not fill quickly, the reservoir is usually emptied at least once every twenty-four hours. After emptying with the suction off, the suction device is reactivated for further collection.
During the filling cycle time interval, and over the extended period of time the device is used, the bacterial count in reservoirs collecting drainage from contaminated wounds increase exponentially as the liquid in the reservoir is a superior bacteria culture medium. In clean, uncontaminated wounds, the reservoir usually becomes contaminated with exogenous bacteria within twenty-four to forty-eight hours due to the repeated opening of the reservoir during emptying. So in either type of wound, the suction drainage collection reservoir becomes a harbor for bacteria as these devices are normally in use for three to five days or longer.
In order to empty the liquid from the closed wound suction drainage device, the collection reservoir is opened, usually by removing a male plug from a female outlet (emptying port) of the reservoir. The contents are then emptied into an open basin or open graduated container. From there, the liquid is transferred to a disposal site such as a toilet or "hopper" (a special flushable sink-like unit). In order to empty the drainage device it is common practice, and with some devices it is essential, to squeeze or compress the device to create a positive pressure in the drainage device to expel the liquid through the outlet. When the contents are so expelled, the drained liquid may be aerosoled due to the rapid expulsion and splashing in the collection receptacle. In addition, even when emptying a reservoir by gravity flow, some splashing of the liquid is almost inevitable. Shaking of the device is also often required to completely empty it as residual pools of exudate are common to collection reservoirs, especially in certain spring activated and balloon type devices. It is important to completely empty the devices as physicians determine the status of the draining wound by the volume of exudate collected over time. In either event, the aerosol or spilled exudate are often heavily laden with bacteria and are obvious sources of nosocomial infection. The bacteria can infect the patient, the person emptying the drainage device as well as other patients or persons in close proximity that may be exposed to the bacteria contained in the aerosol or spilled exudate.
The transmission of hospital infection by aerosol effects is well documented in the medical literature. In order to prevent or reduce aerosol induced cross infection from wall suction systems, hospitals have used bacterial filters on suction collection canisters. Further, other forms of disposable suction collection receptacles are usually considered to be "contaminated waste" and are handled according to special procedures established for handling and disposing of such materials. Portable closed wound suction units have been a necessary exception to the practices followed for the other suction collection devices as they are attached to the patient, and no closed method of handling the waste has been available.
Each time that a drainage device is opened to drain the liquid therefrom, there is also an increased risk of contamination from the outside environment reaching the inside of the drainage device. When the reservoir of the drainage device is contaminated with an outside contanimant, there is a danger of retrograde infection of the patient's wound. Obviously, the more times the drainage device is opened, the greater the danger of inadvertently contaminating the drainage reservoir; and the longer the device is used and the drains are left in place, the greater the possibility of retrograde infection of the patient's wound from outside contaminants. Some surgeons routinely remove the drainage system after three days time even though drainage has not fully ceased due to their fear of retrograde infection of the wound from the ouside contaminants.
There has been disclosed in the prior art systems for collecting liquids from a patient in a first container, and subsequently transferring these liquids to a flexible second container. Examples of devices such as these which are used to collect urine from the bladder of a patient are disclosed in U.S. Pat. No. 3,888,126 (Cross) and U.S. Pat. No. 4,319,573 (Whitlock). The use of flexible collection containers and the like have also been disclosed in the following U.S. patents: U.S. Pat. No. 4,334,537 (Peterson); U.S. Pat. No. 3,312,221 (Overment); U.S. Pat. No. 3,724,461 (Eisenberg); and U.S. Pat. No. 3,926,233 (Brendling).