Old Equipment: PEEP Safety Cited

David Lee

To the Editor

I was very pleased to see in the December 1989 APSF Newsletter a very helpful and timely article relative to the use of older or faulty anesthesia equipment.

In Ms. Nichols’ article, she outlined some features of anesthesia machines and delivery systems which, on older equipment, warranted closer scrutiny to avoid the occurrence of hypoventilation.

Even in today’s modern anesthesia equipment, additional monitors and other safety enhancements are still no substitute for vigilance on the part of the user. This is particularly true where older machines are used. For this mason, I wished to comment further on the use of PEEP valves in connection with these older machines.

It is quite true, as Ms. Nichols states, that the use of external PEEP valves in has on occasion proved hazardous, particularly when the device used was of a unidirectional type. The unidirectional PEEP valve does, indeed, leave too great a possibility for inappropriate placement. Constant vigilance in each successive use of the device is essential in preventing the catastrophic results of incorrect placement of the unidirectional PEEP valve

Integral PEEP values on modern machines require a similar vigilance as well. The possibility always exists that the feature may be left on, as she emphasized, and that the consequences may be serious for the patient who would not tolerate application of PEEP Further, in servicing the integral PEEP valve, the possibility of misassembly creates an unnecessary exposure to liability on the part of the service technician, the anesthetist, and the hospital.

Several types of bidirectional PEEP valves are currently available on the market and provide a welcome relief from the dangers of misapplication and liability. In the case of reversing the prescribed direction of ” type of valve relative to the flow of gas, the PEEP feature is merely bypassed, with no danger of gas-starvation. further, these devices are easier to maintain and service (and at reduced cost) particularly when compared with state-of-the-art integral PEEP system.

David Lee

Technical Services Coordinator Arnbu, Inc.

Hanover, MD