The Solution to Pollution? Dilution!
Why intraoperative lavage is an underused but very helpful technique.
Intraoperative lavage is an underused but very helpful technique. This column will talk mostly about abdominal lavage, but the general concepts apply to any body part—open wounds, the thorax, a fracture site, a joint, etc.—as well as to contaminated or infected surgical sites, such as after anal sac or ear canal surgery.
The mantra “the solution to pollution is dilution” means that the general goal of flushing is to remove debris, bacteria and toxic chemicals from a surgical site by using copious amounts of a warm solution such as saline.
In the case of contamination or infection, it means that we are trying to dilute and remove bacteria to such a low level that the body can then take over and process the remainder.
In the case of peritoneal bile or urine, the goal is to decrease the amount of inflammatory chemicals to the lowest possible level.
Lavage also may be used at room temperature to cool saw blades (e.g. TPLO surgery), drill bits (e.g. fracture repair) and high-speed burrs (e.g. during spinal surgery).
Which Fluid to Use
It is likely that the type of crystalloid fluid you use is irrelevant, as long as it’s a sterile, isotonic and balanced solution with no added dextrose. It probably doesn’t matter because most of the solution should be suctioned out anyway. Practically, most people use warm saline.
The fluid can be poured out of a sterile bag of saline (microwaved or from an incubator). A more convenient option is to use hard plastic bottles (Figure 1).
Alternative ways to flush areas other than the abdomen include a syringe, a bulb syringe or a fluid bag connected to an IV line and a needle.
Adding antiseptics (e.g. chlorhexidine, povidone iodine) or antibiotics to the lavage solution is of no benefit and is potentially harmful.
How to Remove It
Without question, the easiest way to remove abdominal fluid is to use a suction machine. Anybody serious about surgery should own one. They only cost a few hundred dollars—brand new—and plenty of less-expensive, used suction machines are available.
It’s important to remove as much of the fluid as possible at the end of your lavaging session, as leftover fluid interferes with chemotaxis and phagocytosis by white blood cells.
The best suction tip for abdominal surgery is a Poole tip (a metal one costs around $25). A 6-foot suction hose will serve you well in most situations (12 feet is a bit excessive).
How to Handle Local Peritonitis
If you are dealing with generalized peritonitis, there is little doubt that lavage will help improve the outcome. But what should you do when you are facing local peritonitis?
Some argue that flushing the entire abdomen will end up spreading the contamination from the local area to the whole abdomen. A better option would be to lavage locally. If the origin of the contamination is the small intestine, consider exteriorizing the section that is contaminated and flush it outside the abdomen.
Added Benefit of Lavage
One study showed that warm lavage fluid placed in the abdomen actually can help raise the body temperature of a patient (M. Nawrocki, JAAHA 2005).
Surprisingly, the fluid used was hotter than you would think—around 110 F. It enabled increasing the patients’ temperature from 94 to 97 F. It’s a good test of your patience; the lavage fluid must remain in the abdomen for 2 to 6 minutes.
It’s sometimes difficult to extrapolate data from human studies, but here are some relevant points from a British human study (O. Whiteside, Annals of The Royal College of Surgeons of England 2005):
- The majority of surgeons (61 percent) lavaged until the fluid became clear.
- In a case of septic abdomen (i.e. gross pus or fecal peritonitis), 47 percent used saline as the lavage fluid.
- A good reminder: “The successful management of the septic abdomen rests on at least three tenants—systemic antibiotics, control of the source of infection, and aspiration of gross contaminants.”
Dr. Phil Zeltzman is a board-certified veterinary surgeon and author. His traveling practice takes him all over eastern Pennsylvania and western New Jersey. Visit him at DrPhilZeltzman.com or follow him at facebook.com/DrZeltzman.
Nikki Schneck, a veterinary technician near Pottsville, Pa., contributed to this article.
Originally published in the May 2017 issue of Veterinary Practice News. Did you enjoy this article? Then subscribe today!