Carbon dioxide rebreathing

Lofaso F, Brochard L, Touchard D, et al. Evaluation of carbon dioxide rebreathing during pressure support ventilation with airway management system (BiPAP) devices. Chest 1995 108 772-778. 

FIGURE 11-1 Schematic diagram of a closed anesthesia system. [/] Vaporizer for volatile liquid anesthetics. [2] Compressed gas source. [3] Inhalation unidirectional valve. [4] Mask. [5] Unidirectional exhalation valve. [6] Rebreathing bag. [73 Carbon dioxide absorption chamber. 

USE To absorb carbon dioxide in basal metabolism tests, in rebreathing anesthesia systems, in submarines, and in carbon determinations. Caution Strongly corrosive and irri -tating to skin, mucous membranes, eyes. Ingestion can cause severe damage to G.l. tract, death. 

Dahan, A., Berkenbosch, A., DeGoede, J. et al. 1990. On a pseudo-rebreathing technique to assess the ventilatory sensitivity to carbon dioxide in man. /. Physiol. 423 615. 

The treatment of respiratory alkalosis involves rebreathing one s own exhaled air by breathing into a paper bag (not a plastic bag), administering carbon dioxide, and treating the underlying causes of the hyperventilation. 

A closed-circuit apparatus is one in which the exlialation is rebreathed by the wearer after the carbon dioxide has been effectively removed. A suitable oxygen concentration is restored from sources composed of (1) compressed oxygen, (2) chemical oxygen, and (3) liquid oxygen. 

Superoxides have been useful in one type of rebreather system used in closed areas such as submarines, mines, and space vehicles. A rebreather or a closed circuit scuba system removes carbon dioxide and produces oxygen on an as-needed basis. There are a variety of these systems one uses a series of reactions using potassium superoxide as a primary component. The reaction is represented in Equation (12.21) ... 

Chemical canister rebreathers are used only for emergency egress. The canister contains a special chemical that evolves as oxygen when contacted by the moisture and carbon dioxide in exhaled breath (the CO2 and moisture are retained). 

Both fentanyl and Innovar depressed the slope of the rebreathing carbon dioxide response curve to 42% 6 of the values obtained in the same subjects when awake. After the last injection of fentanyl or the fentanyl/droperidol combination the slope of the curve increased to 77% 8 of the control level but after reaching a normal level the respiratory depression recurred, the slope of the curve falling to 55% + 5 of the control value. Subsequently the slope of the curve returned to near normal levels. 

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