A comparison of the incidence of hypercapnea in non-obese and morbidly obese peri-operative patients using the SenTec transcutaneous pCO sub(2) monitor

• Published in: Journal of clinical monitoring and computing 2014-06, Vol.28 (3), p.293-298
• Main Authors: Soto, Roy G, Davis, Maurice, Faulkner, Michael J
• Format: Article
• Language: English
• Subjects: Acidosis; Bismaleimides; Carbon dioxide; Incidence; Monitoring; Monitors; Patients; Surgery
• ISSN: 1387-1307; 1573-2614
• DOI: 10.1007/s10877-013-9534-6

Obese patients are at increased risk for hypoventilation, leading to hypercapnea and acidosis. The primary objective of this study was to compare the incidence of perioperative hypercapnea in non-obese and morbidly obese patients using the SenTec transcutaneous PCO sub(2) (tcPCO sub(2)) monitor. 10 morbidly obese subjects (BMI > 40 kg/m super(2)) undergoing laparoscopic bariatric surgery, and 10 non-obese subjects (BMI < 30 kg/m super(2)) undergoing laparoscopic abdominal procedures were studied, using a standardized anesthesia regimen. TcPCO sub(2) and SpO sub(2) were monitored continuously intraoperatively, and during the first 24 h postoperatively. Opiate consumption, respiratory rate (RR), and pain scores were collected from postanesthesia care unit (PACU) and ward nursing notes. RR, SpO sub(2), and tcPCO sub(2) did not differ significantly between groups during PACU or ward time periods. End-tidal CO sub(2) (EtCO sub(2)) values were similar between groups during the intraoperative period, but tcPCO sub(2) was significantly higher in the obese group at specific time points, and trended towards being higher throughout the case. Our study did not show significant tcPCO sub(2) differences between non-obese and obese post-surgical patients, however, it did allow for continuous, trendable, nonobtrusive monitoring throughout the perioperative period. As V/Q mismatch increases with the PaCO sub(2)/EtCO sub(2) gradient, and this effect is most pronounced in morbidly obese patients, tcPCO sub(2) monitoring may prove to be a useful additional monitor in these patients during the intraoperative period.