J Anesth Perioper Med. 2014;1(2):63-71. https://doi.org/10.24015/ebcmed.japm.2014.0011
From the 1Department of Anaesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China; 2Department of Pharmacology and Physiology, Karolinska Institutet, Stockholm, Sweden.
*Contributed to the work equally.
Correspondence to Dr. Tian-Long Wang at email@example.com.
EBCMED ID: ebcmed.japm.2014.0011 DOI: 10.24015/ebcmed.japm.2014.0011
Retroperitoneal laparoscopy provides less operation injury and faster postoperative recovery. However, long-term pneumoperitoneum increases the risk of hypercapnia that may induce severe postoperative complications, especially in elderly patients. Our study aims at investigating the sensitivity and reliability of continuous transcutaneous carbon dioxide (TcPCO2) monitoring in diagnosing hypercapnia during retroperitoneoscopic surgery in elderly patients and evaluating the effect of positive end-expiratory pressure (PEEP) against retroperitoneum induced hypercapnia.
Fifty-five patients aged over 65 years who were scheduled for selective retroperitoneoscopic surgery under general anesthesia were enrolled. The correlations between TcPCO2, end-tidal partial pressure of CO2 (PETCO2) and arterial CO2 (PaCO2) were evaluated before pneumoperitoneum as well as 30 and 60 minutes after establishment of pneumoperitoneum (time 0, 1 and 2), respectively. Patients were randomly assigned to 5 groups accepting different levels of PEEP: 0, 4, 6, 8 and 10 cm H2O (group I, II, III, IV and V). PaCO2 and PETCO2 were measured at 80 minutes following pneumoperitoneum (time 3). Heart rate (HR), arterial pressure, airway pressure were evaluated throughout surgery.
There was a significant correlation between TcPCO2 and PaCO2 (r=0.87, P<0.01), but the correlation between PETCO2 and PaCO2 was lessened with prolonged pneumoperitoneum. The consistency limit (mean±2SD) between PaCO2 vs. TcPCO2 and PaCO2 vs. PETCO2 was (- 2.86, 5.46) and (- 1.61, 20.11) mm Hg, respectively. A difference of ≤5 mm Hg happened in 96% results of PaCO2 vs. TcPCO2 and 32% of PaCO2 vs. PETCO2 (P<0.01). After the use of PEEP, the PaCO2 was increased in group I and II, sustained in group III, but decreased in group IV and V (P<0.05). In addition, PEEP restored the correlation between PETCO2 and PaCO2 (r=0.6, P<0.01, N=55). The hypercapnia induced enhancement of mean arterial pressure (MAP) and HR was normalized by 10 cm H2O PEEP although the airway plateau pressure (PPLAT) and airway pressure peak (PPEAK) values were elevated.
TcPCO2 may be used as an alternative non- invasive monitoring to predict the PaCO2 levels in elderly patients undergoing long-term retroperitoneoscopic surgery. PEEP (10 cm H2O) combined with low tidal volume (VT=7 ml/kg) ventilation provides a therapeutic approach to ameliorate pneumoperitoneum-induced hypercapnia in these patients.
Declaration of Interests
All authors have no financial support and potential conflicts of interest for this work.
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