Artikel
PCO2-management in the neuro-critical care of patients with aneurysmal subarachnoid haemorrhage – seeking the optimal values
PCO2-Management im Rahmen der intensivmedizinischen Therapie bei aneurysmatischen Subarchnoidalblutungen
Suche in Medline nach
Autoren
Veröffentlicht: | 4. Juni 2021 |
---|
Gliederung
Text
Objective: The partial pressure of the carbon dioxide (PCO2) in the arterial blood is a strong vasomodulator affecting the cerebral blood flow. In the acutely injured brain, the risk of cerebral edema and ischemia depends on the alterations of the PCO2 values. Both complications are related to poor outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to analyze the effect of PCO2 levels on the course and outcome of aSAH.
Methods: All patients of a single institution that were treated for aSAH over a 13.5-year period were included (n=633). The assessed PCO2 values were based on the daily arterial blood gas measurements and recorded for up to 2 weeks after ictus. The study endpoints were: delayed cerebral ischemia (DCI), refractory intracranial pressure (ICP) necessitating decompressive craniectomy, in-hospital mortality, and functional disability at 6 months after aSAH (modified Rankin scale >2). In the multivariate analysis, the association between the PCO2 and the study endpoints were adjusted for the patients’ age, radiographic and clinical severity of aSAH, premorbid and acute respiratory conditions, duration of mechanical ventilation and the need for conservative ICP therapy.
Results: Using the receiver operating characteristic curve, the clinically relevant cutoff for the PCO2 was set at <38 mmHg. The patients with the daily mean PCO2 values <38 mmHg were at lower risk for sustained ICP requiring decompressive surgery (7.3% vs. 13.8%; aOR 0.49, p=0.048), but not for the DCI risk (18.6% vs. 27.5%; aOR=0.45, p=0.084). Finally, PCO2 <38 mmHg was independently associated with the risk of in-hospital mortality (8.1% vs. 17.9%; aOR 0.40, p=0.002) and functional disability (38.5% vs. 56.1%; aOR 0.64, p=0.043).
Conclusion: Patients with aSAH might profit from low-normal PCO2 values during the first weeks after aneurysm rupture. This effect is most likely attributed to the reduction of cerebral edema and associated ICP increase. In addition, despite the known vasoconstrictor effect of a low PCO2, aSAH patients with PCO2 <38 mmHg showed rather a trend to a lower risk of DCI.