Larsen F S, Olsen K S, Ejlersen E, Hansen B A, Paulson O B, Knudsen G M
Department of Hepatology, University of Copenhagen, Denmark.
Hepatology. 1995 Sep;22(3):730-6.
Impairment of cerebral blood flow (CBF) autoregulation may have serious implications for patients with cirrhosis if arterial hypotension occurs during coma, anesthesia, bleeding, or sepsis. In this study, CBF autoregulation was investigated in patients with cirrhosis with no or mild encephalopathy. Ten patients (median age, 45 years; range, 30 to 61 years) and six healthy volunteers (median age, 30 years; range 21 to 61 years) were included. Catheters were placed in a radial artery and in the internal jugular veins. Baseline CBF was measured using single-photon emission computed tomography (SPECT) with concomitant measurements of cerebral arteriovenous oxygen content differences (AVDO2). CBF autoregulation was evaluated using the AVDO2 method and changes in mean flow velocity in the middle cerebral artery (Vmean) as determined by transcranial Doppler (TCD). Mean arterial pressure (MAP) was increased by 30 mm Hg by intravenous norepinephrine, and subsequently decreased by a combination of lower body negative pressure and ganglion blockade, whereas AVDO2 and Vmean were measured at each 5 mm Hg change in MAP. CBF was 61 (range, 45 to 78) mL 100 g-1 min-1 in patients with cirrhosis and 65 (range < 53 to 88) mL 100 g-1 min-1 in volunteers (not significant [NS]). There were no regional differences in CBF between the two groups. Arterial carbon dioxide tension was 31 (23 to 35) mm Hg in patients with cirrhosis and lower, compared with 36 (range, 34 to 47) mm Hg in the volunteers (P < .01). For evaluation of autoregulation, MAP was raised to 116 (range, 100 to 145) and then decreased to 39 (range, 34 to 50) mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)
如果在昏迷、麻醉、出血或脓毒症期间发生动脉低血压，脑血流（CBF）自动调节功能受损可能会对肝硬化患者产生严重影响。在本研究中，对无或轻度肝性脑病的肝硬化患者的CBF自动调节功能进行了研究。纳入了10例患者（中位年龄45岁；范围30至61岁）和6名健康志愿者（中位年龄30岁；范围21至61岁）。将导管分别置于桡动脉和颈内静脉。使用单光子发射计算机断层扫描（SPECT）测量基线CBF，并同时测量脑动静脉氧含量差（AVDO2）。使用AVDO2方法以及经颅多普勒（TCD）测定的大脑中动脉平均血流速度（Vmean）变化来评估CBF自动调节功能。通过静脉注射去甲肾上腺素使平均动脉压（MAP）升高30 mmHg，随后通过下体负压和神经节阻滞相结合使其降低，而在MAP每变化5 mmHg时测量AVDO2和Vmean。肝硬化患者的CBF为61（范围45至78）mL 100 g-1 min-1，志愿者的CBF为65（范围<53至88）mL 100 g-1 min-1（无显著性差异[NS]）。两组之间CBF无区域差异。肝硬化患者的动脉二氧化碳分压为31（23至35）mmHg，低于志愿者的36（范围34至47）mmHg（P<.01）。为评估自动调节功能，将MAP升高至116（范围100至145），然后降至39（范围34至50）mmHg。（摘要截选至250字）
