Standards for humidification and filtration devices.

Abstract

This synopsis of the background to the standardization of medical devices allows a comparison of the functional operation of two regulatory authorities, the FDA and the European Commission. It can be seen that with time they have developed many common features. However, there remains a significant difference with the older style of regulation imposed by the FDA, in particular the obligation to comply with USA Federal Law and Federal Codes of Regulation. Further, the FDA expects manufacturers, when submitting medical devices for approval, to provide their own supportive evidence by showing compliance with ISO and IEC good manufacturing practice and safety standards. Finally, it is only pragmatic to accept that marketing permission for all devices is ultimately overseen, inspected and enforced solely by the FDA. By comparison, within Europe it is the more modern Medical Device Directives of the European Commission that are the statutory legislation. In order to market a medical device, the only fundamental responsibility of the manufacturer is that it must have a CE marking, which is achieved by showing compliance with the Essential Requirements. One means of accomplishing this is to conform with the provisions of relevant harmonized standards. Such concurrence may be verified if needed, by one of the international pool of independent Notified Bodies, who are ultimately overseen by the Competent Authorities of the individual States of the Community. The preparation of standards for medical devices is a slow process, involving the cooperation of the multiple stakeholders with an interest in the device. They are expected to produce a final document that is fair, consistent and practical for all the parties involved, from the initial designer to the final patient to whom the device is attached. Analysis of the three standards applicable to humidifiers, HME and BSF demonstrates some of the difficulties encountered in meeting these obligations. It is to be hoped that the solutions which were found achieve the ultimate goal of all medical device standards-specifically that the equipment should not cause a hazard to either the patient or user. But it is interesting to wonder whether it can be shown that any BSF meets one of the prime requirements of the FDA, to wit that all medical devices must be able to demonstrate efficacy. There is a dearth of clinical trials supporting the allegation of BSF manufacturers that the routine use of these devices improves patient care, which can only be taken to mean that to date such claims are difficult to vindicate. This paralogism must be countered by the indisputable fact that BSF can significantly increase the work of breath-ing, enlarge the deadspace and even, as has been shown recently, result ina complete blockage of the breathing system. Whatever standards are in place with reference to any particular medical device, it must never be forgotten that it is only the clinician who will finally be accountable for the safe and effective operation of the equipment. While caveat emptor must always be the shibboleth of the purchaser, statutory or advisory regulations are no defense for an incompetent user.