METHODS: The single-center, prospective study investigated the effects of RMs (up-titration of positive end-expiratory pressure) on multimodal neuromonitoring in patients with acute brain injury. Our primary focus was on intracranial pressure and secondarily on cerebral perfusion pressure (CPP) and other neurological parameters: cerebral autoregulation [pressure reactivity index (PRx)] and regional cerebral oxygenation (rSO2). We also assessed blood pressure and right ventricular (RV) function evaluated using tricuspid annular plane systolic excursion. Results are expressed as the difference (Δ) from baseline values obtained after completing the RMs.
RESULTS: Thirty-two patients were enrolled in the study. RMs resulted in increased intracranial pressure (Δ = 4.8 mm Hg) and reduced CPP (ΔCPP = -12.8 mm Hg) and mean arterial pressure (difference in mean arterial pressure = -5.2 mm Hg) (all p < 0.001). Cerebral autoregulation worsened (ΔPRx = 0.31 a.u.; p < 0.001). Despite higher systemic oxygenation (difference in partial pressure of O2 = 4 mm Hg; p = 0.001) and unchanged carbon dioxide levels, rSO2 marginally decreased (ΔrSO2 = -0.5%; p = 0.031), with a significant drop in arterial content and increase in the venous content. RV systolic function decreased (difference in tricuspid annular plane systolic excursion = -0.1 cm; p < 0.001) with a tendency toward increased RV basal diameter (p = 0.06). Grouping patients according to ΔCPP or ΔPRx revealed that those with poorer tolerance to RMs had higher CPP (p = 0.040) and a larger RV basal diameter (p = 0.034) at baseline.
CONCLUSIONS: In patients with acute brain injury, RMs appear to have adverse effects on cerebral hemodynamics. These findings might be partially explained by RM\'s impact on RV function. Further advanced echocardiography monitoring is required to prove this hypothesis.
方法:单中心,前瞻性研究调查了RMs(呼气末正压向上滴定)对急性脑损伤患者多模态神经监测的影响.我们的主要重点是颅内压,其次是脑灌注压(CPP)和其他神经系统参数:脑自动调节[压力反应性指数(PRx)]和局部脑氧合(rSO2)。我们还评估了使用三尖瓣环平面收缩期偏移评估的血压和右心室(RV)功能。结果表示为与完成RM后获得的基线值的差异(Δ)。
结果:32名患者被纳入研究。RM导致颅内压升高(Δ=4.8mmHg),CPP降低(ΔCPP=-12.8mmHg)和平均动脉压(平均动脉压差=-5.2mmHg)(所有p<0.001)。脑自动调节恶化(ΔPRx=0.31a.u.;p<0.001)。尽管全身氧合较高(O2分压差异=4mmHg;p=0.001)且二氧化碳水平不变,rSO2略有下降(ΔrSO2=-0.5%;p=0.031),动脉含量显着下降,静脉含量增加。RV收缩功能下降(三尖瓣环平面收缩偏移差异=-0.1cm;p<0.001),RV基础直径有增加的趋势(p=0.06)。根据ΔCPP或ΔPRx对患者进行分组显示,对RM耐受性较差的患者在基线时具有较高的CPP(p=0.040)和较大的RV基础直径(p=0.034)。
结论:在急性脑损伤患者中,RM似乎对脑血流动力学有不利影响。这些发现可能部分解释为RM对RV功能的影响。需要进一步的超声心动图监测来证明这一假设。