THE MILLER TRACHEAL CUFF PRESSURE CONTROL VALVE - CLINICAL USE IN CONTROLLED AND SPONTANEOUS VENTILATION

A constant pressure differential valve for the control of tracheal tube cuff pressure was tested under clinical conditions. Fifty‐one patients underwent controlled ventilation and 20 patients were allowed to breathe spontaneously. Nitrous oxide 66% with oxygen 33% and halothane were used via a circle system. With controlled respiration at afresh gas flow of 3–10 l.min −1, the expiratory cuff pressures of 10.1–16 cmH2sO and the inspiratory cuff pressures of 23.4–32.4 cmH2O were below venous and arterial mucosal capillary perfusion pressures respectively. Cuff pressures were unaltered with time. Methylene blue instilled into the larynx did not appear in the trachea. Fifty‐two control patients had the same incidence of sore throat (40%) and hoarseness (30%) at 24 h. With spontaneous ventilation, fresh gas flows of 5–15 l.min−1 maintained the cuff pressure above 10 cmH2O. We conclude that this valve prevents excessive tracheal cuff pressure while maintaining the airway seal. Copyright © 1993, Wiley Blackwell. All rights reserved