CARBON-DIOXIDE DYNAMICS DURING APNEIC OXYGENATION - THE EFFECTS OF PRECEDING HYPOCAPNIA

Citation
Ba. Gentz et al., CARBON-DIOXIDE DYNAMICS DURING APNEIC OXYGENATION - THE EFFECTS OF PRECEDING HYPOCAPNIA, Journal of clinical anesthesia, 10(3), 1998, pp. 189-194
Citations number
19
Categorie Soggetti
Anesthesiology
ISSN journal
09528180
Volume
10
Issue
3
Year of publication
1998
Pages
189 - 194
Database
ISI
SICI code
0952-8180(1998)10:3<189:CDDAO->2.0.ZU;2-L
Abstract
Study Objective: To compare the rate of increase of arterial carbon di oxide tension (PaCO2) during apneic oxygenation preceded by acute resp iratory hypocapnia with that during apnea preceded by respiratory euca pnia. Design: Randomized, prospective, single crossover study. Setting : Operating room at a teaching hospital. Patients: 19 ASA physical sta tus I, II, and III patients requiring general endotracheal anesthesia and invasive monitoring for elective surgery. Interventions: Two venti latory states preceding apneic oxygenation were studied in each patien t. The first respiratory state was established using controlled mechan ical ventilation in the stable, anesthetized patient, followed by a 5- minute period of apneic oxygenation. Arterial and mixed central venous blood gas samples were obtained simultaneously pier to and at 1-minut e intervals during apnea, Ventilatory parameters were then changed to establish the second respiratory state. During the subsequent period o f apnea, the study: was repeated as above. Measurements and Main Resul ts: Arterial and mixed central venous partial pressure of carbon dioxi de (pCO(2)) levels were measured. A greater increase in PaCO2 was foun d during the first minute of apneic oxygenation in the hypocapneic gro up compared with the eucapneic group. The venoarterial gradient of pCO (2) was also greater in the hypocapneic group prior to apnea. Conclusi ons: Acute hypocapnia compared with eucapnia prior to apneic oxygenati on is associated with a greater rise in PaCO2 in the anesthetized pati ent. This finding may be due in part to widening of the venoarterial g radient of pCO(2). (C) 1998 by Elsevier Science Inc.