title: The effects of different analgesic regimens on transcutaneous CO2 after major surgery.
abstract: Ventilatory impairment may be detected by a rise in transcutaneous carbon dioxide levels (PtcCO(2)). This observational study assessed the clinical utility of PtcCO(2) monitoring in the postoperative period, and quantified the effect of different peri-operative analgesic regimens on postoperative respiratory function. Following pre-operative baseline PtcCO(2) recording, continuous PtcCO(2) monitoring was performed in 30 patients after major colorectal surgery for up to 24 h. Mean postoperative values of PtcCO(2) were 1.3 kPa (95% CI 1.0-1.5) higher than pre-operative values (p < 0.001). Patients receiving intravenous opioid patient controlled analgesia had a significantly higher elevation in postoperative PtcCO(2) compared to patients receiving epidural infusion analgesia, 1.8 kPa (CI 1.5-2.1) vs 0.7 kPa (CI 0.5-0.9) respectively (p < 0.001). The mean rise in PtcCO(2) following a single intravenous bolus of morphine delivered via PCA was 0.05 kPa (SEm 0.01), peaking at 12 min post-dose. The transcutaneous capnometer successfully recorded data for 98% of the total time it was applied to patients.
authors.affiliation: Department of Anaesthesia, Critical Care and Pain Medicine, University of Edinburgh, Royal Infirmary, Edinburgh, EH16 4SA.
authors.forename: J G
authors.initials: JG
authors.lastname: McCormack
authors.forename: K P
authors.initials: KP
authors.lastname: Kelly
authors.forename: J
authors.initials: J
authors.lastname: Wedgwood
authors.forename: R
authors.initials: R
authors.lastname: Lyon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016058:Analgesia, Patient-Controlled; D000700:Analgesics / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000494:pharmacology; D001785:Blood Gas Monitoring, Transcutaneous; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D007420:Intestine, Large / Q000601:surgery; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D010313:Partial Pressure; D011182:Postoperative Care / Q000379:methods*; D012119:Respiration / Q000187:drug effects*; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000175:diagnosis
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D002245:Carbon Dioxide