Continuous carbon dioxide partial pressure monitoring in lung transplant recipients

Living-donor lobar lung transplantation (LDLLT) recipients often have hypercapnia preoperatively, which confers a risk of worsened hypercapnia intraoperatively. We reviewed our experience with continuous carbon dioxide partial pressure (PtcCO2) monitoring in LDLLT to evaluate its accuracy and feasibility. We also assessed preoperative and intraoperative carbon dioxide levels in LDLLT recipients.

Twenty-six LDLLT recipients without pulmonary hypertension underwent preoperative nocturnal and intraoperative PtcCO2 monitoring, determined with a TOSCA-500 monitor.

Maximal preoperative nocturnal PtcCO2 (72.7 ± 19.3 mmHg) was significantly correlated with preoperative resting arterial carbon dioxide partial pressure (PaCO2; 55.1 ± 11.6 mmHg, r(2)=0.84). PtcCO2 was more correlated with PaCO2 (range, 39-192 mmHg) during LDLLT (r(2)=0.93) than with end-tidal carbon dioxide partial pressure (r(2)=0.38). Intraoperative continuous PtcCO2 monitoring was useful for evaluating real-time carbon dioxide levels. Intraoperative PtcCO2 did not exceed maximal preoperative nocturnal PtcCO2 in 13 recipients (50%) but temporarily exceeded it in 11 recipients (42%). PtcCO2 was further elevated in 2 recipients (8%) requiring the early establishment of cardiopulmonary bypass. There were no complications related to PtcCO2 monitoring.

PtcCO2 monitoring in LDLLT recipients is useful as a means for determining intraoperative carbon dioxide levels, which increase dramatically and can be predicted preoperatively and assessed in a timely manner.