Variability of Resting Carbon Dioxide Tension in Patients with Intracranial Steno-occlusive Disease

Abstract

Abstract Introduction Controlling the partial pressure of carbon dioxide (PaCO2) is an important consideration in patients with intracranial steno-occlusive disease to avoid reductions in critical perfusion from vasoconstriction due to hypocapnia, or reductions in blood flow due to steal physiology during hypercapnia. However, the normal range for resting PCO2 in this patient population is not known. Therefore, we investigated the variability in resting end-tidal PCO2 (PETCO2) in patients with intracranial steno-occlusive disease and the impact of revascularization on resting PETCO2 in these patients. Setting and Design Tertiary care center, retrospective chart review Materials and Methods We collected resting PETCO2 values in adult patients with intracranial steno-occlusive disease who presented to our institution between January 2010 and June 2021. We also explored postrevascularization changes in resting PETCO2 in a subset of patients. Results Two hundred and twenty-seven patients were included [moyamoya vasculopathy (n = 98) and intracranial atherosclerotic disease (n = 129)]. In the whole cohort, mean ± standard deviation resting PETCO2 was 37.8 ± 3.9 mm Hg (range: 26–47). In patients with moyamoya vasculopathy and intracranial atherosclerotic disease, resting PETCO2 was 38.4 ± 3.6 mm Hg (range: 28–47) and 37.4 ± 4.1 mm Hg (range: 26–46), respectively. A trend was identified suggesting increasing resting PETCO2 after revascularization in patients with low preoperative resting PETCO2 (<38 mm Hg) and decreasing resting PETCO2 after revascularization in patients with high preoperative resting PETCO2 (>38 mm Hg). Conclusion This study demonstrates that resting PETCO2 in patients with intracranial steno-occlusive disease is highly variable. In some patients, there was a change in resting PETCO2 after a revascularization procedure.