CHAPTER SEVENTEEN: Pulsed Lavage with Suction

At the end of this chapter, the learner will be able to:

1. Describe the mechanical effects of pulsed lavage with suction at the cellular and tissue levels.

2. Select patient situations when the use of pulsed lavage with suction might be indicated.

3. Relate advantages and disadvantages of using pulsed lavage with suction for wound healing.

4. Apply precautions associated with the use of pulsed lavage with suction for wound management.

5. Follow infection control precautions during treatment using pulsed lavage with suction.

Pulsed lavage with suction (PLWS) is a portable, battery-powered, handheld device utilized by physicians, nurses, and physical therapists to promote wound healing. The two primary components of PLWS are (1) the pulsed delivery of sterile irrigation fluid onto the wound surface and (2) the simultaneous suction and removal of contaminated irrigation fluid and wound debris (FIGURE 17-1). The combination of pulsed lavage with concurrent suction has been shown to be beneficial in wound healing.¹ Literature supports the use of PLWS for wound cleansing, removal of topical agents, irrigation, mechanical debridement, reduction of surface bacteria, and stimulation of cells associated with tissue healing and wound closure.^2,3,4

PLWS has been utilized in health care for decades beginning in the 1960s when US Army physicians first adapted modified WaterPik units for the irrigation of contaminated combat wounds.^5,6,7,8 The original units have been advanced to the light-weight portable units that are currently used in both surgical irrigation and wound management in in-patient, outpatient, and home health settings.⁹ The gun-like shape of the handpiece makes the device easy to grip and maneuver and an assortment of tips adapt to different wound sizes and locations (FIGURE 17-2). While different vendors (BARD Davol, Inc, Warwick, RI; Stryker, Kalamazoo, MI; Zimmer, Inc, Warsaw, IN) market disposable PLWS units with different options, the basic equipment requirements are essentially the same (TABLE 17-1).

PLWS delivers pulsed, pressurized irrigation at controlled pounds per square inch (psi) along with simultaneous removal or suction of contaminated irrigation fluid, thereby combining the benefits of both positive and negative pressure in one modality. Research supports that the combination of these pressure forces facilitates wound cleansing, debridement of slough, loosening of nonviable tissue, reduction of surface bacteria, increased local perfusion, and stimulation of granulation tissue.^1,2,10

Positive Pressure

Positive pressure hydrotherapy for the management of open wounds can assist in general wound cleansing, debridement, and tissue stimulation (see TABLE 17-2). Whirlpool (WP) therapy, once considered the primary method of hydrotherapy,¹¹ utilizes a turbine to generate positive pressure irrigation (FIGURE 17-3).^1,3 However, with WP therapy, the psi created by the turbine at the wound surface has not been documented.¹¹ Research supports that positive pressure hydrotherapy delivered at too low a psi can be ineffectual for wound cleansing and debridement; too high, and wound tissues are damaged and surface bacteria may be pushed deeper into the wound bed.^12,13,14 For safe and effective delivery, the Agency for Health Care Policy and Research, the National Pressure Ulcer Advisory Panel, and the European Pressure Ulcer Advisory Panel recommend irrigation pressures for wound management stay between 4 and 15 psi.^12,15 PLWS units are designed so that providers select known psi settings within the safe 4 to 15 psi range (FIGURE 17-4).

Negative Pressure

Benefits associated with the negative-pressure component of PLWS are tissue stimulation, locally increased perfusion, reduction of surface bacteria,¹ and removal of irrigation fluid (see TABLE 17-3). Research indicates that the suction force generated with the application of negative pressure stimulates granulation tissue proliferation and epithelialization through the process of cellular deformation and strain.^2,10,16,17 Negative pressure also increases tissue perfusion by causing arterioles to dilate and thereby increasing local blood flow.² Increased perfusion supports granulation tissue formation and enhances the body’s ability to destroy and digest bacteria in the wound.¹⁸ PLWS also assists with reducing bioburden^1,19 through the following mechanical means:

1. Debridement: the physical removal of loosened nonviable tissue and bacteria from the wound environment; removal of nonviable tissue also decreases food availability for remaining bacteria

2. Irrigation: removes microorganisms on the wound surface and in exudate as the irrigation fluid is evacuated

Bioburden may also be decreased by adding topical antibacterial medications to irrigation solutions.^2,16 This can be especially beneficial in treating severely immunocompromised patients or patients with heavily contaminated, traumatic injuries with or without exposed bone.⁴ However, PLWS reduces surface bacteria primarily through mechanical means, and there is no promotion of bacterial resistance (an increasing concern as drug resistance increases) when normal saline alone is used as the irrigation fluid.²⁰ Additionally, when using antibiotic irrigation solutions (eg, bacitracin), the potential for allergic reactions to those medications must be considered²¹ whereas normal saline has little to no allergic potential. The selection of antibacterial irrigation is based on systemic as well as local wound presentation.

The beneficial effects of PLWS have been discussed; however, full understanding of how PLWS facilitates healing at the cellular level requires further discussion. PLWS delivers positive pressure through pulsation of irrigation fluid. When a pulse of water strikes a tissue, the force of the pulse causes a brief compression of that tissue.^4,8 Between pulses, target tissues decompress or recoil.^4,8 PLWS produces multiple, rapid iterations of tissue compression-decompression cycles that mechanically dislodge bacteria,^4,8,19 nonviable tissue, and debris from the wound bed. Adherent nonviable tissue remaining after a PLWS treatment is hydrated and loosened, thereby assisting natural phagocytosis.¹⁰ Hydration and loosening with PLWS is also an excellent method of preparing adherent nonviable tissue for sharp debridement. Compression-decompression mechanical manipulation also assists in exudate removal,¹⁰ which is especially important in chronic wounds since chronic wound fluid is damaging to wound tissues and contributes to delayed healing (FIGURE 17-6).^17,18,23,24

The negative-pressure component of PLWS also produces significant effects at the tissue and cellular levels via the mechanical stress^10,17 or stretch¹⁸ on the structural components of extracellular matrix and local cells. This mechanical deformation^17,18 has been shown to promote granulation tissue formation² by stimulating increased protein synthesis by fibroblasts and by increasing cellular proliferation.^10,18

Additionally, the warm irrigation fluids affect tissues by facilitating local increased vasodilation. Necessary components for tissue healing are delivered through the blood, and stimulating increased local blood flow delivers more leukocytes (white blood cells), antibodies, oxygen, and nutrients to the wound site.¹⁰ Increased local vasodilation also improves the delivery of systemic antibiotics to the area and increases the removal of toxic waste products.¹⁰

The use of PLWS is indicated for a variety of wounds that need atraumatic cleansing, debridement, tissue stimulation, and bacterial reduction (see TABLE 17-4) provided all precautions have been addressed. Specific etiologies that are appropriate for PLWS include wounds caused by neuropathy, pressure, venous insufficiency, and postsurgical incisional dehiscence or amputation healing by secondary intention.² PLWS is also indicated for the removal of bacteria and debris in wounds associated with traumatic injury and bone exposure.⁴ Utilization of the flexible tips allows appropriate and safe use of PLWS for the irrigation and cleansing of tunnels, tracts, and undermining (FIGURES 17-7, 17-8).

There are no strict contraindications for the use of PLWS; however, there are several precautionary situations that should be cleared prior to treatment (see TABLE 17-5). Loehne² recommends cautious use of PLWS application close to “major vessels, cavity linings, and bypass graft sites” in the outpatient or home health setting where quick access to advanced medical support may not be available. Wounds of the face are another area for special precaution due to the superficial nature of vessels and nerves in this area; it has been recommended that only licensed professionals with extensive experience using PLWS perform the procedure in this area.²

Since PLWS is a method of debridement, caution is recommended when treating patients on anticoagulant therapy² and treatment should be discontinued if active bleeding occurs.²⁵ PLWS encourages increased local blood flow and may cause increased blood loss from a wound with questionable or fragile hemostasis. Wounds with exposed tissues such as bone or tendon should also be approached cautiously to prevent tissue damage. In situations of questionable hemostasis or easily damaged, exposed named structures, selection of a lower psi within the 4 to 15 psi range is recommended. Further adaptation for painful or friable tissue may include the use of a Yankauer suction tip for removal of fluids. The Yankauer exerts no negative pressure on the tissue, therefore decreases the risk of bleeding (FIGURE 17-9).

Caution is also advised when the wound bed cannot be clearly visualized, for example, in the presence of tunneling, undermining, or tracts.^1,2 Knowledge of tract depth and possible tunnel connection with body cavities prior to administering PLWS is needed in order to provide safe and effective treatment. Monitoring the amount of water that is pulsed in and suctioned out is recommended when treating wounds with tracts, thereby ensuring removal of all contaminated fluid.

The potential for wound hypothermia when using PLWS is a concern. Wounds heal faster close to body temperature (37°C-38°C)^2,10 and it can take hours for wound tissue to recover from cool temperature irrigation. For convenience, IV bags designated for PLWS treatment may be heated in hot water or stored in a blanket warmer. Irrigation fluids at room temperature are not recommended for PLWS considering that most clinical settings maintain ambient temperatures much cooler than normal body temperature.

Parameters

Clinical judgment in selection and adjustment of treatment parameters is important in wound management because of the dynamic nature of wound healing. Parameter selections for PLWS are related to specific changes in the wound status. If the desired results are not realized, parameters are adjusted to facilitate an optimal patient response. Parameters for PLWS include type of irrigation tip, irrigation force (psi), suction force, temperature of irrigation fluid, and frequency and duration of treatment (TABLE 17-6).

Irrigation Force

The positive pressure of irrigation used for wound care is between 4 and 15 psi. Adequate wound cleansing and debridement can usually be achieved using 8 to 12 psi.²⁶ In situations of anticoagulation therapy, fragile hemostasis, exposed named structures, or intense pain, lower psi settings are recommended.¹⁶ Similarly, low psi pressure ranges (2-6 psi) are utilized for irrigation of tracts and tunnels.¹ Higher forces (12-15 psi) are recommended for removal of infected tissue, thick mucinous exudate, or adherent necrotic tissue.^4,26 Loehne² recommends lower psi selections (4-6 psi) for initial treatments to gauge tissue response. This also allows the patient to become familiar with the sensation and sound of active PLWS and can help alleviate apprehension or anxiety associated with an unfamiliar method of treatment.

Because PLWS delivers pressurized irrigation fluids, risk for fluid aerosolization and the possible transport of bacteria is a concern. It has been shown that PLWS aerosolization can cause the transport of bacteria as far as 8 feet away from the treatment area.²⁷ In 2004, Maragakis et al⁶ published data documenting a multidrug-resistant bacterial outbreak linked to PLWS aerosolization. Since that time, guidelines regarding PLWS use have been developed. See “Application” below and TABLE 17-7.

Suction Force

The recommended suction setting is 60 to 100 mmHg² with the lower end of the range used for situations of fragile hemostasis or pain, and the upper end for increased mechanical manipulation to remove debris and stimulate cellular proliferation. For cavity wounds with large amounts of undermining, painful wounds, or friable tissue, the Yankauer suction tip allows for safer and more comfortable suction of irrigation fluids.

Temperature of Irrigation Fluid

As indicated previously, using irrigation fluids warmed to 37°C to 38°C helps prevent wound tissue hypothermia and facilitates local vasodilation.^2,3,10 Skin loss in superficial wounds causes loss of body heat; this loss increases with full-thickness wounds that involve the loss of insulating subcutaneous fatty tissue. Tissue healing may slow down or halt with lower temperatures; therefore, maintaining a warm wound environment is advised. Shetty et al¹⁰ also describe overall patient relaxation and reduction of localized pain as secondary benefits of warm irrigation applications.

Frequency and Duration

For wounds with infection, odor, or greater than 50% necrotic tissue, twice daily PLWS applications may be beneficial.^2,25,26 For general cleansing and tissue stimulation, PLWS may be applied daily or scheduled for every other, every second, or every third day depending on results.^2,10 PLWS should typically be discontinued after 1 week without improvement in wound status.² While giving general consideration to these guidelines, professionals should apply sound clinical judgment in prescribing frequency and duration parameters based on specific patient and tissue responses.

Personal Protective Equipment and Environmental Guidelines

To protect professionals from risks associated with aerosolization during PLWS use and to protect patient and wound from environmental contaminants, standard personal protective equipment (PPE) including hair cover, face shield or mask/goggles, waterproof gown, shoe covers, and gloves are advised during treatment (FIGURE 17-10).² After Maragakis et al⁶ directly linked bacterial aerosolization with PLWS, the Centers for Disease Control and Prevention developed additional infection control guidelines^2,27 that included PPE for the patient as well as stringent environmental controls (see TABLE 17-7).

The PLWS unit was originally designed as a single-use item; however, improved infection control measures allow for reuse of handpieces when used on the same patient. For example, the battery-operated handheld device equipped with a diverter tip that diverts contamidated irrigation fluids from returning through the handheld unit can be reused on the same patient; the unit is thoroughly disinfected after use and stored in a tightly closed sterile bag between treatments (FIGURE 17-11).

Some manufacturers now routinely include a sterile, clear plastic sleeve designed to cover the handpiece, making it easier to clean for reuse during the patient’s next treatment. When the handheld unit is reused on the same patient, a new sterile divertor tip should be used for each treatment—tips are not to be reused even on the same patient. Additionally, some PLWS units provide sterile, clear plastic sheeting that can be draped over the treatment area with the PLWS tip inserted through a central hole so that aerosolization risk is further reduced (FIGURE 17-12).

The risk of aerosolization and projectile contamination must be considered when PLWS is used during surgical procedures.^20,28,29 In addition to clear plastic sheeting, different devices have been documented^20,29 as minimizing risks during surgery, including the Wound Irrigation Bag (Pulse Care Medical LLC, North Andover, MA) and the Vi-Drape Isolation Bag (Becton Dickinson AcuteCare Division, Franklin Lakes, NJ). Witte et al²⁸ have reported success in decreasing aerosolization and projectile risks using a simple sterile package insert over the surgical site during pressurized irrigation.

Treatment Preparation and Application

In preparation for PLWS treatment, the patient is positioned comfortably and draped appropriately (as indicated in TABLE 17-7 “PLWS Infection Control Guidelines” above) with the target area for treatment exposed for easy access. A waterproof or water-resistant drape is placed under the treatment area along with extra toweling to absorb irrigation fluid not evacuated by suction. If treating multiple areas during the same treatment session, the cleanest area is treated first and the most contaminated area is treated last in order to limit cross-contamination. If possible, the patient is positioned so that excess irrigation runoff from one open area does not drain into other open areas (FIGURE 17-13).

A warmed IV bag of irrigation fluid is suspended from an IV pole or hook with PLWS tubing inserted into the bag so fluid can be pulled from the bag into the PLWS unit. Depending on wound characteristics, number of wounds, and treatment goals, more than one bag of irrigation fluid may be necessary. If so, extra irrigation bags wrapped in dry toweling to maintain warmth and extra suction canisters should be within easy reach of the treatment area to facilitate transition of supplies with little interruption in treatment (FIGURE 17-14).

Wall or portable suction is connected to the collection canister and to tubing from the PLWS unit that carries contaminated irrigation fluid from the suction tip at the treatment area to the canister. Any other openings in the collection canister (sometimes located on the lid) are closed or sealed to prevent loss of suction. Irrigation collection canisters are single-use items^6,27 and should be placed in biohazard waste containers for disposal (FIGURE 17-15).

A sterile field is prepared for protection of and access to additional supplies such as different tips, sterile instruments for sharp debridement, sterile gauze (for soft debridement or when treating patients with fragile hemostasis in case minimal bleeding occurs), and dressings. Silver nitrate sticks, surgical thrombin, or pressure with sterile gauze are recommended if bleeding occurs during treatment. If bleeding cannot be stopped with pressure (usually for at least 15 minutes without removal of the pressure bandage) or if arterial bleeding is suspected (detected by the pulsating arterial flow), a physician should be contacted immediately.

Any specialized equipment included with the PLWS unit aimed toward decreasing aerosolization risk (such as sterile protective sheeting or PLWS unit covers) are recommended as well as all personal and patient protective measures previously described.

Openings on the extended, flexible tips used for irrigating tunnels and tracts are typically located at the very end of the tip. Consequently, these tips should be moved in and out of tunnels and tracts frequently during treatment so all areas of the sidewalls are involved in the treatment. Using the index finger and thumb to help guide the tip during this procedure provides better control and ease of movement. Any PLWS tip, whether cone or flexible, is considered a single-use item and is not reused for any reason.

The combination of positive and negative pressure benefits in PLWS makes this modality an effective, efficient, and convenient method of hydrotherapy delivery. Site-specific application and sterility of supplies greatly reduce contraindications for use and risks for cross-contamination. Positive and negative pressure manipulation removes bacteria, nonviable tissue, and debris from the wound bed at safe, known psi levels while promoting granulation tissue formation. Warm irrigation fluid stimulates local vasodilation, assists in maintaining local normothermia, and promotes patient relaxation and pain reduction. PLWS combines the long documented benefits of hydrotherapy into an advanced wound management modality with several advantages over traditional whirlpool (see TABLE 17-8).