caa a22 4500 465826032 CHVBK 20180323112149.0 cr unu---uuuuu 170327e19900401xx s 000 0 eng 10.1007/BF02828284 doi (NATIONALLICENCE)springer-10.1007/BF02828284 Relationship between arterial carbon dioxide and end-tidal carbon dioxide when a nasal sampling port is used [Elektronische Daten] [Stephen McNulty, John Roy, Marc Torjman, Joseph Seltzer] End-tidal carbon dioxide (ETCO2) values obtained from awake nonintubated patients may prove to be useful in estimating a patient's ventilatory status. This study examined the relationship between arterial carbon dioxide tension (PaCO2) and ETCO2 during the preoperative period in 20 premedicated patients undergoing various surgical procedures. ETCO2 was sampled from a 16-gauge intravenous catheter pierced through one of the two nasal oxygen prongs and measured at various oxygen flow rates (2, 4, and 6 L/min) by an on-line ETCO2 monitor with analog display. Both peak and time-averaged values for ETCO2 were recorded. The results showed that the peak ETCO2 values (mean = 38.8 mm Hg) correlated more closely with the PaCO2 values (mean = 38.8 mm Hg; correlation coefficient r = 0.76) than did the average ETCO2 values irrespective of the oxygen flow rates. The time-averaged PaCO2-ETCO2 difference was significantly greater than the PaCO2-peak ETCO2 difference (P < 0.001). Values for subgroups within the patient population were also analyzed, and it was shown that patients with minute respiratory rates greater than 20 but less than 30 and patients age 65 years or older did not differ from the overall studied patient population with regard to PaCO2-ETCO2 difference. A small subset of patients with respiratory rates of 30/ min or greater (n = 30) did show a significant increase in the PaCO2-ETCO2 difference (P < 0.001). It was concluded that under the conditions of this study, peak ETCO2 values did correlate with PaCO2 values and were not significantly affected by oxygen flow rate. However, obtaining peak ETCO2 values is clinically more difficult, especially when partial air-way obstruction is present. Little, Brown and Company, 1990 Carbon dioxide: arterial, end-tidal nationallicence Measurement techniques: capnography nationallicence Monitoring: carbon dioxide, capnography nationallicence McNulty Stephen Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut Roy John Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut Torjman Marc Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut Seltzer Joseph Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut Journal of Clinical Monitoring Springer Netherlands 6/2(1990-04-01), 93-98 0748-1977 6:2<93 1990 6 10877 https://doi.org/10.1007/BF02828284 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02828284 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- McNulty Stephen Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut NATIONALLICENCE 700 1- Roy John Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut NATIONALLICENCE 700 1- Torjman Marc Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut NATIONALLICENCE 700 1- Seltzer Joseph Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA aut NATIONALLICENCE 773 0- Journal of Clinical Monitoring Springer Netherlands 6/2(1990-04-01), 93-98 0748-1977 6:2<93 1990 6 10877 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer