Transtracheal Delivery of Gas Decreases the Oxygen Cost of Breathing

Abstract

Transtracheally administered gases decrease inspired minute ventilation in both dogs and humans. To test if this is associated with a decrease in the oxygen cost of breathing and to evaluate subsequent changes in the breathing pattern, we studied five patients with chronic respiratory diseases while they spontaneously breathed air and different flows of tracheally administered gases. In a blinded crossover design, the gas consisted of either oxygen or air at 2, 4, and 6 L/min. Oxygen cost of breathing was estimated by the calculation of pleural pressure-time index (PPTI). The pattern of breathing was evaluated utilizing the tension time index for the diaphragm (TTdi). There were significant decreases in PPTI when the patients received 2, 4, and 6 L/min of transtracheal oxygen or air. TTdi also decreased as gas flow increased. This drop was significant at 6 L/min flow for both gases. We conclude that transtracheally administered gas reduces the oxygen cost of breathing. It also changes the respiratory pattern of the diaphragm to a less demanding pattern. This may offer an alternative form of treatment to rest overworked respiratory muscles.

ERS/ATS statement on interventional pulmonology

“…In order to maintain competence, o5 procedures?yr -1 should be performed. The suggested reading for this section is [73][74][75][76][77][78].…”

How Important Is the Differentiation between Apnea and Hypopnea?

“…It is known that the administration of O2 reduces minute ventilation [71], usually by reducing the tidal volume. In some patients, the respiratory rate is also decreased [72], This is most marked with transtracheal application of oxygen [73][74][75], Since minute ventilation is directly correlated with the work of breathing in normal individuals [76] and in respiratory failure [77], oxygeninduced hypoventilation means an additional unloading for the RP. This mechanism may be the principal reason for prolonged life expectancy in COPD patients with LTO2 [25,64,67], On the other hand, in patients with severe hypercap nia.…”

Mechanical Ventilation

“…More recently, studies have shown that intratracheal administration of gas enabled a reduction in tidal volume, dead space, and minute ventilation in the same type of patients (Benditt et al 1993;Hurewitz et al 1991;Bergofsky and Hurewitz 1989). After the Stresemann pilot study, studies in man remained rare.…”