BBI Contributing Writer

SAN DIEGO, California Mornings dawned a little dreary in normally sunny San Diego during the latter part of March, but that fact didn't slow down the active attendees to the 51st annual Association of Perioperative Nurses (AORN; Denver, Colorado) congress. Some 6,000 employees of AORN exhibitors competed for the attention of the 7,000 or so operating room (OR) nurses in attendance. Scientific presentations included topical issues such as herbal supplement interaction with anesthetics and hypothermia's impact on recovery outcomes for surgical patients, along with scores of other subjects.

According to Alan Agins, PhD, of PRN Associates (Cranston, Rhode Island), what the OR nurse doesn't know about dietary supplements can hurt the surgical patient. He estimated that nearly 50% of U.S. patients take some form of herbal or natural supplement on a regular basis. As of 2001, people in the U.S. spent $17.8 billion on just supplements (not counting vitamin and minerals). Many patients believe that the supplements are "natural" and therefore safe.

One of the myths surrounding supplements is that chemicals derived from common household plants can't possibly be useful as drugs. "In reality," Agins noted, "when you look at the PDR [Physician's Desk Reference], 30% to 40% of commonly used drugs come from plant sources." Atropine comes from the "deadly nightshade" or belladonna plant. Purple foxglove is a common garden plant used as a source of digitalis and linoxin. The opiate poppy is used to create morphine. Very dangerous and powerful drugs do come from plants. And, while a little can cure, a lot can kill.

Agins reminded his audience that herbal supplements are not regulated by the FDA. They are classed as foods and therefore not required to have clinical studies, proof of efficacy or safety. He said that healthcare practitioners need to understand that some herbal supplements can interact negatively with prescribed medications and anesthetic agents.

Ginger, gingseng and ginko biloba can affect platelet aggregation and lead to extensive bleeding. Vitamin E in large doses also can impair clotting mechanisms. Soy and St. John's wort can decrease the effects of coumadin. Kava and melatonin are weak central nervous system depressants, but can be additive to general anesthetics or pain medications. Other drugs can increase liver enzymes, causing more rapid metabolization of prescribed medications. The cholesterol-lowering effects of Lipitor can be blocked by St. John's wort.

Agins recommended that healthcare practitioners tell their patients to discontinue all herbal supplements two weeks before and two weeks after surgery. He reminded OR nurses to remember that supplements are not assessed by the FDA, to always ask about herbs and dietary supplements preoperatively, and to gather knowledge about supplements' impact from scientific sources. As he put it, "The word 'natural' doesn't mean safe. Poison ivy and botulism are natural, too."

Perioperative hypothermia was much-discussed at the AORN gathering. Every year, 14 million surgical patients suffer from inadvertent hypothermia (core body temperature of less than 96.8 F). This situation has been called the most frequent, preventable complication of surgery. The human body has an amazing capability of maintaining its core temperature close to 98.6 F. In spite of this, nationwide, between 30% and 40% of all surgical patients are hypothermic upon admission to the recovery room.

Meta-analysis of data taken from a number of different published research articles shows that maintaining normothermia is associated with significant reductions in negative outcomes like surgical site infection, bleeding disorders, myocardial infarction and prolonged hospital stays. Hypothermia promotes wound infections in a number of ways, such as increased bacterial growth (33% to 56% increase in bacterial colonization) and increased oxygen tension of the tissue, resulting in higher infection rates and delayed healing.

Patients who are hypothermic also can experience reduced cardiac performance. Decreased contractility, impaired relaxation and a profoundly negative inotropic effect occur more frequently in hypothermic patients. Hypothermia also reduces the body's ability to metabolize many drugs and can have profound effects on neuromuscular blocking agents, local anesthetics and cardiovascular drugs used during the perioperative period. Finally, hypothermia has a dulling effect on the central nervous system, reducing both motor and cognitive function. Consequently, hypothermic patients typically take longer to recover from surgery.

Forced warm air or convective warming has been shown to be most effective in preventing and treating perioperative hypothermia for three primary reasons: the blanket surrounds or hugs the patient; air is the medium of transfer to all areas of the body, not just areas touched by the blanket; and 70% of the patient's body is exposed to the moving air with whole body blankets. Unfortunately, like all medical devices, forced warm air machines can be misused. The manufacturer of one of the leading brands the Bair Hugger is Arizant (Eden Prairie, Minnesota), which calls this misuse "hosing." Hosing is when a forced-air warming system is used without attaching a blanket.

OR nurses and anesthesia personnel are definitely concerned for patient safety, but some may be unaware of the serious consequences of hosing. Those consequences include a higher temperature at the end of the hose nozzle or the nozzle coming into contact with the patient's skin, causing a thermal injury. Clinicians are encouraged to use these devices according to manufacturer's instructions.

Walking the aisles

Most nursing attendees do a full walking review of all the exhibitors' booths, making sure they see everything and don't miss a new or exciting product or service. By the end of day two, fashionable dress shoes had been replaced with sandals or tennis shoes. Among the newest services/products were a device for measuring scope quality, an antibiotic suture and 240 different opportunities to earn continuing education credits.

Minimally invasive surgical procedures are a growing percentage of all surgeries performed today. Most require the use of an endoscope, and endoscopes are, by their nature, fragile. Overstressing, sterilization processes, handling procedures and inadequate repairs all challenge the life of the scope and the budget of OR materials personnel. During the congress, Lighthouse Imaging (Portland, Maine) introduced a new tool to help the OR administrator and the biomedical team reduce costs associated with the care and maintenance of both rigid and flexible scopes. The EndoSpector is a tabletop inspection machine. Using the EndoSpector, the technician or nurse can determine the quality of the scope before sterilization, assuring that it is performing to specification. Unnecessary repairs can be reduced and returning scopes can be checked for incoming quality.

The EndoSpector uses custom-designed optics and video-generated targets to quantitatively assess the function of medical endoscopes. Precision mechanisms allow simple adjustments for a wide variety of different viewing angles, lengths and diameters. Measurement choices include image resolution (or sharpness), brightness and uniformity of illumination. The EndoSpector is the first endoscope tester that doesn't need a skilled technician to accurately conduct the measurements.

"The world's No. 1 suture just got better," said Ethicon (Somerville, New Jersey), a Johnson & Johnson (New Jersey) company. The Vicryl Plus antibacterial suture was featured during the AORN gathering. The company said it is the world's first antibacterial suture. First approved by the FDA in 2002, Vicryl Plus is designed to reduce bacterial colonization on the suture. The active ingredient, Irgacare MP, is known to be effective against staphylococcus aureus, staphylococcus epidermis and methicillin-resistant strains of staphylococcus (MSRA and MRSE), the leading surgical site bacteria. Surgical site infections (SSIs) are a serious concern for the 27 million surgical patients in the U.S. each year. According to the Centers for Disease Control and Prevention (CDC; Atlanta, Georgia), 2% to 3% of surgeries result in SSIs. That translates to 675,000 occurrences of surgical site infections annually.

Vicryl Plus begins to work the moment it comes into contact with the patient by creating an "active zone" around the suture. The active ingredient is the purest form of triclosan (Irgacare MP) a broad-spectrum antibacterial agent. Triclosan is an antiseptic, not an antibiotic, and is nontoxic at the given concentration.

"When I prepare for surgery, I take every precaution, such as scrubbing my hands and wearing gloves to protect my patient against bacterial contamination," said Philip Barie, MD, associate professor of surgery, at Weill Medical College of Cornell University (New York). "With the clearance of Vicryl Plus, I now have another tool to add to my routine to help protect patients. This device represents a major improvement in suture technology that holds the promise of making surgery safer for all patients who undergo surgery, as it is the first device ever to inhibit bacterial colonization of the suture."