OF INSUFFLATORS - ENDOSCOPY SURGERY?

AUGUST/2009

BY: CHARLES E. MEISCH ENDOSCOPIC CONSULTANT NBS GROUP SUPPLY 257 LIVINGSTON AVENUE, NEW BRUNSWICK, NJ 08901, USA 1-732-610-2042

As the U.S. and Europe continue to see the breakthrough use of Endoscopic Surgery versus conventional surgery in all areas, it appears the procedures increasing most rapidly are cholecystectomies, female sterilization, lap bariatric, bowel resection, hernia repair, hysterectomy, appendectomy, anti-reflux, and nephrectomy, most of which require the use of an insufflator. Usually electronic in design, insufflators are differentiated by flow rates, ranging from 9.9 LPM to 45LPM at 1 PSI or lower. They are also pressure-limited gas flow regulators used to produce a pneumoperitoneum.

According to AORN's 1995 Standards and Recommended Practices, "Insufflator equipment should include a disposable hydrophobic (liquid blocking) filter." Over the past few years, health care providers in the United States have come to the consensus that filter devices are a necessary part of all laparoscopic procedures that employ insufflation. The need for filters for the retention of particulates such as inorganic debris, rust, metal filings and Teflon has been recognized by the majority of practitioners. However, it is important to choose a filter which also prevents body fluids from entering insufflators. For this purpose, the filter must be hydrophobic.

In January of 1996, the Medical Devices Agency released a Safety Notice stating that patient fluid contamination continues to be found in the internal gas circuits of laparoscopic insufflators and that practitioners should, "ensure that any bacterial filter/liquid trap assembly provided and recommended by the manufacturer of the insufflator be used and disposed of appropriately." In May of 1992, The Emergency Care Research Institute (ECRI) released a statement which warned, "blood was being delivered to a patient via an insufflator." This blood apparently came from a prior patient. Manufacturers and various hospital clinic engineers confirm this is a common occurrence. The right hydrophobic filter (liquid trap) stops the reflux (backflow) of blood and other body fluids as well as particulates, preventing contamination of the insufflators and cross contamination between patients.

N OF INSUFFLATORS -IN ENDOSCOPY SURGERY?

AUGUST/2009

Because of this dual hazard, it is important to specify both the particle retention rating and the level of hydrophobicity required when selecting a filter for use with insufflation. NBS Group Supply recommends that an insufflation filter be rated at 99.99% (particle retention), 0.1 micron, and should have a hydrophobicity rating of 50mm Hg. NBS Group Supply offers a wide range of media and connectors to address the specific needs of your application. These specifications ensure not only the retention of particulate, but under operating conditions, the retention of aqueous fluids as well.

PARTICULATE RETENTION The particle retention specification of a filter designates what percentage of particulate of a certain size or greater will be trapped by that filter.

HOW MUCH HYDROPHOBICITY IS ENOUGH? Recently the Canadian Government issued a warning in their alert to all hospital administrators basically stating that once the internal gas circuit of an insufflator is contaminated with liquids or gases from the patient cavity, a potential hazard of cross contamination is usually created. In one of the incidents reported, a filter had been used, but it failed to provide protection against liquid backflow. Subsequent discussions with the manufacturer revealed that the filter was not recommended for the purpose of backflow preventions.

THE CONTAMINATION OF INSUFFLATORS THE NEXT MAJOR PROBLEM IN ENDOSCOPY SURGER

Hydrophobicity is the characteristic of a filter media, which allows it to repel water, or water based substances such as body fluids. To provide protection against reflux during insufflation, a filter must have a hydrophobicity rating above the pressure that can be exerted in a reverse direction. For insufflation, that rating is 50mm Hg for 10 minutes. In the above example, the filter being discussed was considered to be "hydrophobic", but it did not carry a hydrophobic rating strong enough to retain body fluids under these conditions.

Every hydrophobic filter media has a pressure level at which aqueous liquids can be forced through the pores. This level is the "water breakthrough" pressure. Water breakthrough is also affected by the length of time the pressure is applied. While many filters are hydrophobic, this statement does not mean that the filter will be hydrophobic at all pressures, or that it is hydrophobic enough for a particular application.

Hydrophobicity is only a relative characteristic and must be accompanied by a specific pressure and time designation to be valid. For example, the claim "this filter is hydrophobic" would be more valid if it read "this filter has a hydrophobicity rating of 50mm Hg pressure."

CUSTOMIZATION

NBS Group Supply offers a wide range of options to ensure the correct performance of an insufflator. The filter specification, retention rating, level of hydrophobicity, sterile or non-sterile, labeling, tube length, connectors, and packaging are all calculated to be used with most insulators. It is important to remember insufflation tubing in the U.S. falls under a Class I status. This means that any company can take a common medical gas filter, assemble it to tubing, and call it an insufflation tubing set. All that is required is to register with the FDA and comply with the FDA's cGMP's, but not necessarily submit for premarket approval. Under these criteria, the set may or may not work with your insufflator. NBS Group Supply specifically tests filters so that they meet all necessary medical and FDA criteria. Unlike other companies, our tubing sets go beyond what is required by the FDA and have been submitted to the FDA for premarket approval as Class II devices. This means not only the product, but the packaging, the method of sterilization and the labeling are all carefully reviewed. The FDA has reviewed our application and has approved it for the intended use thereby removing any doubt that our sets are truly manufactured as insufflation tubing sets and not just gas filtering systems. We feel this is important for you to know. For a copy of the approval, please contact our corporate office in New Brunswick, NJ.