The Effect of Position on PaCO2 and PETCO2 in Patients Undergoing Cervical Spine Surgery in Supine and Prone Position.
BACKGROUND
As per American Society of Anesthesiologists guidelines, continuous monitoring of end tidal carbon dioxide (PETCO2) is recommended as standard II basics of anesthetic monitoring especially to ensure adequate ventilation during all anesthetics. Continuous monitoring of PETCO2 can also be used as a guide to maintain the partial pressure of carbon dioxide in arterial blood (PaCO2) to desired level during the surgery.


OBJECTIVE
To study the effect of position on PaCO2 and PETCO2 during cervical spine surgery in prone position.


METHODS
Following institutional ethical committee approval and written informed consent, a prospective study was conducted in 40 patients of 18 to 60 years and of American Society of Anesthesiologists I and II scheduled for cervical spine surgery in prone position. In operating room, the patient is connected to standard monitoring and intravenous access was secured. A 20 G arterial cannula was placed. General anesthesia administered and oral endotracheal intubation done. Baseline values of systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, temperature, SpO2, Ppeak, Pmean, and Pplateau were measured in supine position. For each patient the capnometer was calibrated before use. The P(a-ET)CO2 was calculated in supine position (S1). The PaCO2 and ETCO2 were measured after prone positioning P1, at each subsequent hour (P2, P3, P4), and on completion of the procedure in supine position (S2). The mean values were used for further analysis.


RESULTS
The PETCO2 and PaCO2 decreased significantly in cervical spine surgery patients with change of position from supine to prone with no significant change in arterial to end tidal CO2 gradient (P(a-ET)CO2).


CONCLUSIONS
PETCO2 can be used as a reliable guide to estimate PaCO2 during cervical spine procedures in prone position.
Department of Anaesthesiology and Critical Care, Nizam's Institute of Medical Sciences, Hyderabad, Telangana, India.
Monu
M
Yadav
Elmati Praveen
EP
Reddy
Ashima
A
Sharma
Dilip Kumar
DK
Kulkarni
Ramachandran
R
Gopinath
D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General; D001784:Blood Gas Analysis; D019296:Capnography; D002245:Carbon Dioxide / Q000097:blood*; D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D056888:Patient Positioning / Q000379:methods*; D016684:Prone Position; D011446:Prospective Studies; D013131:Spine / Q000601:surgery*; D016683:Supine Position; D055815:Young Adult
D002245:Carbon Dioxide