Twan T.J. Aalbers*, Laurens C. Vroon, Sjoerd W. Westra, Gert Jan Scheffer, Lucas T. van Eijk and Michiel Vaneker
Background: Pulmonary vein isolation is widely performed under procedural sedation and analgesia (PSA). During PSA, depth and rate of ventilation are decreased which can lead to alveolar hypoventilation, resulting in increased arterial CO2 levels and respiratory acidosis. This study aims to investigate the degree of respiratory depression and resulting respiratory acidosis under routine pulmonary vein isolation procedures.
Methods and findings: We performed a single center prospective observational study at the cardiac catheterization unit of the Radboud University Medical Centre between October 2019 and September 2020. Twenty patients, aged between 18 and 80 years, ASA 2, scheduled for pulmonary vein isolation with PSA were included. Medication used to maintain adequate PSA was limited to propofol and remifentanil. We performed blood gas analysis before the start of PSA and every 30 minutes during PSA and recovery.
Procedural times varied considerably with a median of 50 (range 30-290) minutes. The concentration of arterial CO2 increased significantly within 30 minutes from 4.81 ± 0.66 kPa to 7.13 ± 0.84 kPa. Thereafter, no further increase in CO2 was observed. The PH decreased proportionally, from 7.43 ± 0.06 to 7.29 ± 0.03 and remained stable throughout the procedure until the end of PSA. After cessation of PSA, CO2 normalized to baseline with 30 minutes.
Conclusion: During pulmonary vein isolation procedures performed with PSA a significant increase in CO2 levels was found. This hypercapnia resulted in a respiratory acidosis in all patients, which stabilized within 30 minutes. Longer procedure times do not lead to higher CO2 levels.
