Carbon dioxide flooding of the pericardium-An old practice revisited

The Effect of Carbon Dioxide Insufflation on Cognitive Function During Cardiac Surgery

“…Given the lack of evidence implicating gaseous microemboli in neurocognitive impairment in cardiac surgery, and the drawbacks of serological markers, it is difficult to draw conclusions from trials using surrogate markers of neurocognitive impairment. The importance placed on surrogate markers and the theoretical basis of CO 2 use has led to previous review articles on this topic leading to different conclusions 65‐67 . In order to conclusively justify the use of CO 2 , prospective randomized controlled trials should have: (1) a statement regarding power of the trial; (2) CO 2 delivered through the most effective technique; (3) methods of measuring gaseous microemboli (TCD, carotid ultrasound, intraoperative TEE) or postulated effects of gaseous microembolization (MRI, DWI, fMRI, cerebral blood flow, cerebral oximetry); and (4) measurement of neurocognitive outcomes using the current gold standard with appropriate statistical analysis.…”

“…The importance placed on surrogate markers and the theoretical basis of CO 2 use has led to previous review articles on this topic leading to different conclusions. [65][66][67] In order to conclusively justify the use of CO 2 , prospective randomized controlled trials should have: (1) a statement regarding power of the trial; (2) CO 2 delivered through the most effective technique; (3) methods of measuring gaseous microemboli (TCD, carotid ultrasound, intraoperative TEE) or postulated effects of gaseous microembolization (MRI, DWI, fMRI, cerebral blood flow, cerebral oximetry); and (4) measurement of neurocognitive outcomes using the current gold standard with appropriate statistical analysis. None of the five trials conducted so far in the literature has had these four design features that are mandatory to answer the question of neurocognitive benefit (Table 1).…”