Pulsed lavage with suction (PLWS) is a portable, battery-powered, handheld device with two primary components: (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.^2–4

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.^5–8 The original systems have been advanced to light-weight portable units that are currently used for both surgical irrigation and wound management in the 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). The basic equipment requirements are essentially the same for any system, and are listed in TABLE 17-1.

PLWS delivers pulsed, pressurized irrigation at controlled pounds per square inch (psi) along with simultaneous removal of the contaminated irrigation fluid by suction, 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 less than 4 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.^12–15 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 between 4 and 15 psi for wound management.^12,16 PLWS units are designed so that providers select known psi settings within the safe 4–15 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 (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.^2,10,17,18 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.¹⁹ PLWS also assists with reducing bioburden^1,20 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.^2,17 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.²² Additionally, when using antibiotic irrigation solutions (eg, bacitracin), the potential for allergic reactions to those medications must be considered²³ whereas normal saline has little to no allergic potential. The selection of antibacterial irrigation is based on systemic as well as local wound presentation.¹⁵

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, nonviable tissue, and debris from the wound bed.^4,8,20 Adherent nonviable tissue remaining after a PLWS treatment is hydrated and loosened, thereby assisting natural phagocytosis,¹⁰ as well as facilitating easier tissue-specific sharp debridement. Compression–decompression mechanical manipulation also assists in exudate removal,¹⁰ which is especially important in chronic wounds because chronic wound fluid is known to be damaging to wound tissues and thereby contributing to delayed healing (FIGURE 17-6).^18,19,24,25

The negative-pressure component of PLWS also produces significant effects at the tissue and cellular levels via the mechanical stress^10,18 or stretch¹⁹ on the structural components of extracellular matrix and local cells. This mechanical deformation^18,19 has been shown to promote granulation tissue formation² by stimulating increased protein synthesis by fibroblasts and by increasing cellular proliferation.^10,19

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, especially if the wound is in the inflammatory phase of healing (see TABLE 17-4). Specific etiologies that are appropriate for PLWS include wounds caused by neuropathy, pressure, venous insufficiency, post-surgical 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 unless there is concern that the wound extension leads to a body cavity (eg, thoracic or abdominal) (FIGURES 17-7 and 17-8).