A comparison of transcutaneous and end-tidal measurements of CO2 tension in laparoscopic surgery

Choi, Hey Ran; Lim, Yun Hee; Park, Hae Gyun; Lee, Sangseok; Yon, Jun Heum; Hong, Ki Hyuk

Case Report

General Article

Anesthesia and Pain Medicine 2009;4(1):55-59.
Published online January 30, 2009.

A comparison of transcutaneous and end-tidal measurements of CO2 tension in laparoscopic surgery

Hey Ran Choi, Yun Hee Lim, Hae Gyun Park, Sangseok Lee, Jun Heum Yon, Ki Hyuk Hong

Department of Anesthesiology and Pain Medicine, Sanggye Paik Hostipal, College of Medicine, Inje University, Seoul, Korea. anelim1@sanggyepaik.ac.kr

Abstract

BACKGROUND
In laparoscopic surgery with pneumoperitoneum, end-tidal CO2 (PeTCO2) monitoring may inaccurately estimate PaCO2 due to ventilation/perfusion mismatch. This study assessed the clinical usefulness and accuracy of transcutaneous CO2 (PtCCO2) monitoring during laparoscopic surgery.
METHODS
Thirty-two patients with ASA physical status 1 requiring laparoscopic surgery were recruited. We measured PaCO2, PeTCO2, and PtCCO2 before and 20 min after pneumoperitoneum. To compare differences in PeTCO2/PaCO2 and PtCCO2/PaCO2, we determined bias values (mean difference between values) and precision (standard deviation of bias) with a Bland-Altman plot and compared them with a Student's t-test.
RESULTS
Bias and precision values of PeTCO2/PaCO2 and PtCCO2/PaCO2 were 6.6 +/- 2.0 mmHg, 1.2 +/- 2.8 mmHg before pneumoperitoneum and 8.5 +/- 2.8 mmHg, 2.1 +/- 4.5 mmHg 20 min after pneumoperitoneum. PtCCO2/PaCO2 differences were significantly smaller than PeTCO2/PaCO2 differences (P< 0.05).
CONCLUSIONS
In laparoscopic surgery, PtCCO2 monitoring is more accurate than PeTCO2 monitoring for assessing PaCO2 levels.

Key Words: carbon dioxide, laparoscopic surgery, monitoring, transcutaneous