In Reply:—

The need to adjust different devices, such as electric syringes, blood pressure sensors, and respirators, during the compression and decompression stages of treatment with hyperbaric oxygen is known. 1However, rather than being a problem of program readjustment, our case concerned the cessation of function of the epidural patient-controlled analgesia pump at a pressure of 2 absolute atmospheres (ATA), 2as occurred in one of the cases mentioned in the letter by Levecque et al. 

Because the treatment schedule with hyperbaric oxygen in anaerobic infections involves 90-min sessions as 3 ATA, 1we think it is wiser not to use the more sophisticated and expensive electronic pumps for patient-controlled analgesia, bearing in mind that rescue analgesia can be used for short periods to maintain good pain control, if necessary.

We are studying the behavior of these systems, and we welcome further correspondence that might help to resolve the problem.

Barriot P, Chave S, Pitti R: Oxigénothérapie hyperbare (OHB) (Principles et indications), Editions Techniques. Paris, Encycl Méd Chir, 1995, Anesthésie-Réanimation. Edited by Horay P. Paris, 36-940-A-10, p 10
Sanchez-Guijo JJ, Benavente MA, Crespo A: Failure of a patient-controlled analgesia pump in a hyperbaric environment. A nesthesiology 1999; 91:1540–2