Estimation of arterial CO2 partial pressure by measurement of tracheal CO2 during high-frequency jet ventilation in patients with a laryngectomy.
Tracheal and arterial CO2 partial pressures were measured simultaneously in 27 laryngectomized patients both while they were awake and during high-frequency jet ventilation. Tracheal gas was sampled during brief interruptions of high-frequency jet ventilation. Agreement between tracheal and arterial CO2 partial pressures was assessed using the Bland-Altman method. The tracheal-arterial CO2 partial pressures gradient during spontaneous breathing was significantly lower (P < 0.0002) than during high-frequency jet ventilation. During spontaneous ventilation, the bias was -0.77 kPa (95% CI = -0.99 to -0.55 kPa), and the upper and lower limits of agreement were 0.29 kPa (95% CI = -0.11 to -0.7 kPa) and -1.83 kPa (95% CI = -2.24 to -1.43 kPa). During high-frequency jet ventilation, the bias was -1.61 kPa (95% CI = -1.76 to -1.46 kPa), and the limits of agreement were -0.48 kPa (95% CI = -0.75 to -0.21 kPa) and -2.74 kPa (95% CI = -3.01 to -2.47 kPa). Despite the poor agreement between tracheal CO2 partial pressure and arterial CO2 partial pressure, it is sufficient to allow for adjustment of ventilator settings during jet ventilation.
Novak-Janković
V
V
Clinical Department of Anaesthesiology and Intensive Therapy, University Medical Centre Ljubljana, Slovenija.
Paver-Erzen
V
V
Fajdiga
I
I
Bovill
J G
JG
Manohin
A
A
Zargi
M
M
D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006611:High-Frequency Jet Ventilation; D006801:Humans; D007825:Laryngectomy; D008297:Male; D008875:Middle Aged; D014132:Trachea / Q000378:metabolism*
D002245:Carbon Dioxide