Product reviews: Pro-Nox and Alexis CES

The views of the author are personal opinions and do not necessarily represent the views of Contemporary Ob/Gyn. Dr. Greenberg personally tests all the products he reviews. He has no conflicts of interest to report with respect to the content of this article.

Background

Like sushi, cappuccino and The Office, many ideas need to be foreign standards for a long time before Americans cotton to them. Such was the case in obstetrics with inhaled anesthetics for relief of labor pain. Use of nitrous oxide for analgesia during childbirth was first described by Dr. Stanislav Klikovich in Russia in 1881.¹ Although inhalational N2O for parturients has been in wide use in the UK for well over 100 years, it was almost nonexistent in the United States until recently. In July 2013, the Pro-Nox Nitrous Oxide Delivery System was cleared by the FDA for sale in the United States and it is now readily available for American women.

Design/Functionality

The Pro-Nox Nitrous Oxide Delivery System is a patient-controlled inhaled analgesia system that delivers a 50% oxygen and 50% nitrous oxide mixture for the relief of pain and anxiety. While at first glance the system’s tanks and tubing give it the appearance of a miniature petrochemical refinery, the system is actually fairly simple and has several important safety features built in. First, the system is 100% pneumatically driven, which means that it is fully portable without the need for plug-ins and can be easily moved as needed. Second, it is designed with a single-patient-use circuit that attaches to an internal demand valve to ensure minimal risk of infection between patients. Third, it comes with a variety of options (such as an active or passive scavenger system or wall mounts) to accommodate different labor settings. And, most importantly, it has an automated safety shut-off system that prevents improper gas mixtures in the event that either the oxygen or nitrous oxide tanks are empty or fail.

In use on our labor floor, the Pro-Nox has pretty much been a winner. For the right patient, it is great and provides the labor analgesia option that we had been lacking (something between intravenous/intramuscular narcotics and an epidural). It is portable and easy to set up in cases such as the multip with active labor. It is safe and, it is effective for the right person. The only real complaints surround the tanks and valves, which can be persnickety to change over. But, the system is pretty gas-frugal so these changeovers are not too frequent.

Innovation

It seems a bit awkward to call a technology introduced in 1881 innovative in 2015 but the people at CAREstream do deserve some “attaboys” for building a system that fits comfortably on a modern labor floor governed by rigorous patient-safety and Occupational Safety and Health Administration regulations. Although Pro-Nox is far from the first system to deliver nitrous oxide for analgesia, it has lowered the bar sufficiently to encourage universal use of this option in the United States.

Clinical Transformative Potential

Pro-Nox has tremendous clinical transformative potential in that it has helped our obstetric service change our practice within our comfort zone to include a labor analgesia option that had previously not been available to our patients with older nitrous oxide delivery systems.

Summary

Nitrous oxide for labor analgesia is nothing to laugh at. A 2012 Cochrane review concluded, “All women in labour should have the opportunity to choose some non-invasive method of relatively effective and safe analgesia at short notice when they wish it during labour. Inhaled pain relief, such as nitrous oxide ... may be a very useful additional method for pain relief.”² Nitrous oxide for labor analgesia is not a panacea and will not universally replace epidurals. However, in my opinion, it should be an option everywhere from sea to shining sea. The Pro-Nox Nitrous Oxide Delivery System offers a safe, convenient starting place for this technology and I think it is worth a try.

References

1. Richards W, Parbrook GD, Wilson J. Stanislav Klikovich (1853-1910). Pioneer of nitrous oxide and oxygen analgesia. Anaesthesia. 1976;31(7):933–940.

2. Klomp T, van Poppel M, Jones L, Lazet J, Di Nisio M, Lagro-Janssen AL. Inhaled analgesia for pain management in labour. Cochrane Database Syst Rev. 2012 Sep 12;9.

Background

In the last 2 years, contained tissue extraction (CTE) has dominated professional discourse in minimally invasive gynecologic surgery from both philosophical and technical perspectives. For a surgical discipline focused over the last 40-odd years on get bigger out through smaller incisions, the sudden move away from open morcellation has left many eyes seeking the next technical edge to help get the MIGS train back onto a safer track. To that end, seemingly every quarter, a new bag in which to place to-be-extracted tissues appears on the market to address this latest challenge. This review will focus on Applied Medical’s Alexis Contained Extraction System.

Design/Functionality

The Alexis Contained Extraction System is a clever extension of Applied’s well-established Alexis retractor technology. With the same semi-rigid rim attached to a heavyweight PVC bag, the Alexis Contained Extraction System has a comfortable feel for anyone who has previously used Alexis retractors. The 6500-cc bag is big enough to accommodate almost all pathology that is typically removed, while rolling the rim over the bag allows it to shrink as needed. The bag comes with a tag on a string attached to the rim, which is strong enough that is can be used to pull the bag out through the incision once the specimen is inside. In addition to the bag, the “system” comes with a 12-mm Hassan-style Kii balloon fixation trocar as well as a flexible neck guard to protect the lining from tears from the knife used for morcellation.

In use in the operating room, the Alexis Contained Extraction System worked much as expected. The bag’s sturdy rim nicely facilitated insertion of the bag through a 3-cm skin incision and, once inside the body, the rim kept the bag opened, which again made getting the specimen into it easier. The polymer membrane was hefty enough to endure a lot of tugging and to resist tearing. The only caveat is that the bag’s size (6500 cc) coupled with the rim’s large mouth fill most of the pelvis and lower abdomen and can limit visibility when large specimens are involved. But large specimen cases are always challenging and, overall, this bag did make it easier. Separate from the bag itself, I was less impressed with the neck guard. Conceptually, it seems like a great idea, but in practice, it just added bulk to the already narrow incision and hindered rather than helped the tissue extraction process. Finally, the addition of the trocar was completely superfluous for me. I never used it in any of my cases and would prefer to see it removed from the system to help lower the cost of the device.

Innovation

I generally liked the Alexis Contained Extraction System and think is a clever adaption of the company’s standard Alexis technology, especially considering the short timeline in which it was developed and brought to market. I love the way Applied tweaked what they had to give us what we needed.

Clinical Transformative Potential

While the Alexis Contained Extraction System is an excellent tissue extraction bag, it isn’t going to transform the MIGS world. In the end, it is just another bag and more technology is still needed in this space to help solve the challenges the discipline is now facing with contained tissues extraction.

Summary

For today, for cold-knife contained tissue extraction, the Alexis Contained Extraction System is as good a product as can be found on the market. At 6.5 L, I think it is bigger than it needs to be for universal appeal but smaller iterations likely will soon appear. I suspect some surgeons will swear by it while other will favor a different product. Either way, for those looking for contained tissues extraction solutions, I highly recommend giving it a try to see if this is the bag you seek.