AUTHOR=Sørensen Henrik , Grocott Hilary P. , Niemann Mads , Rasmussen Allan , Hillingsø Jens G. , Frederiksen Hans J. , Secher Niels H. TITLE=Ventilatory strategy during liver transplantation: implications for near-infrared spectroscopy-determined frontal lobe oxygenation JOURNAL=Frontiers in Physiology VOLUME=5 YEAR=2014 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2014.00321 DOI=10.3389/fphys.2014.00321 ISSN=1664-042X ABSTRACT=

Background: As measured by near infrared spectroscopy (NIRS), cerebral oxygenation (S_cO₂) may be reduced by hyperventilation in the anhepatic phase of liver transplantation surgery (LTx). Conversely, the brain may be subjected to hyperperfusion during reperfusion of the grafted liver. We investigated the relationship between S_cO₂ and end-tidal CO₂ tension (EtCO₂) during the various phases of LTx.

Methods: In this retrospective study, 49 patients undergoing LTx were studied. Forehead S_cO₂, EtCO₂, minute ventilation (VE), and hemodynamic variables were recorded from the beginning of surgery through to the anhepatic and reperfusion phases during LTx.

Results: In the anhepatic phase, S_cO₂ was reduced by 4.3% (95% confidence interval: 2.5–6.0%; P < 0.0001), EtCO₂ by 0.3 kPa (0.2–0.4 kPa; P < 0.0001), and VE by 0.4 L/min (0.1–0.7 L/min; P = 0.0018). Conversely, during reperfusion of the donated liver, S_cO₂ increased by 5.5% (3.8–7.3%), EtCO₂ by 0.7 kPa (0.5–0.8 kPa), and VE by 0.6 L/min (0.3–0.9 L/min; all P < 0.0001). Changes in S_cO₂ were correlated to those in EtCO₂ (Pearson r = 0.74; P < 0.0001).

Conclusion: During LTx, changes in S_cO₂ are closely correlated to those of EtCO₂. Thus, this retrospective analysis suggests that attention to maintain a targeted EtCO₂ would result in a more stable S_cO₂ during the operation.