Mayer S A, Solomon R A, Fink M E, Lennihan L, Stern L, Beckford A, Thomas C E, Klebanoff L M
Department of Neurology, Columbia-Presbyterian Medical Center, New York, New York, USA.
Neurosurgery. 1998 Apr;42(4):759-67; discussion 767-8. doi: 10.1097/00006123-199804000-00048.
Subarachnoid hemorrhage (SAH) predisposes patients to excessive natriuresis and volume contraction. We studied the effects of postoperative administration of 5% albumin solution on sodium balance and blood volume after SAH. We also sought to identify physiological variables that influence renal sodium excretion after SAH.
Forty-three patients with acute SAH were randomly assigned to receive hypervolemia or normovolemia treatment for a period of 7 days after aneurysm clipping. In addition to a base line infusion of normal saline solution (80 ml/hr), 250 ml of 5% albumin solution was administered every 2 hours for central venous pressure (CVP) values of < or =8 mm Hg (hypervolemia group, n = 19) or < or =5 mm Hg (normovolemia group, n = 24).
Both groups demonstrated relative volume expansion in base line measurements. The hypervolemia group received significantly more total fluid, sodium, and 5% albumin solution than did the normovolemia group and had higher CVP values and serum albumin levels (all P < 0.02). Cumulative sodium balance was even in the hypervolemia group and persistently negative in the normovolemia group, because of sodium losses that occurred on Postoperative Days 2 and 3 (P = 0.03). In a multiple-regression analysis of all patients, 24-hour sodium balance correlated negatively with glomerular filtration rate (GFR) and positively with serum albumin levels, after correction for sodium intake (P < 0.0001). Hypervolemia therapy seemed to paradoxically lower GFR (P = 0.10) and had no effect on blood volume, which declined by 10% in both groups. Pulmonary edema requiring diuresis occurred in only one patient in the hypervolemia group.
Supplemental 5% albumin solution given to maintain CVP values of >8 mm Hg prevented sodium and fluid losses but did not have an impact on blood volume in our patients, who were hypervolemic in base line measurements. The natriuresis that occurs after SAH may be mediated in part by elevations of GFR. In addition to acting as a colloid volume expander, 5% albumin solution lowers the GFR and promotes renal sodium retention after SAH. These properties may limit the amount of total fluid required to maintain a given CVP value and hence may minimize the frequency of pulmonary edema.
蛛网膜下腔出血（SAH）使患者易发生钠排泄过多和容量收缩。我们研究了蛛网膜下腔出血后术后给予5%白蛋白溶液对钠平衡和血容量的影响。我们还试图确定影响蛛网膜下腔出血后肾钠排泄的生理变量。
43例急性蛛网膜下腔出血患者在动脉瘤夹闭术后随机分为接受高血容量或正常血容量治疗7天。除基础输注生理盐水溶液（80 ml/小时）外，对于中心静脉压（CVP）值≤8 mmHg的患者（高血容量组，n = 19）或≤5 mmHg的患者（正常血容量组，n = 24），每2小时给予250 ml 5%白蛋白溶液。
两组在基础测量中均表现出相对容量扩张。高血容量组比正常血容量组接受了显著更多的总液体、钠和5%白蛋白溶液，并且具有更高的CVP值和血清白蛋白水平（所有P < 0.02）。高血容量组的累积钠平衡为零，而正常血容量组持续为负，这是由于术后第2天和第3天出现钠丢失（P = 0.03）。在对所有患者进行的多元回归分析中，在校正钠摄入量后，24小时钠平衡与肾小球滤过率（GFR）呈负相关，与血清白蛋白水平呈正相关（P < 0.0001）。高血容量治疗似乎反常地降低了GFR（P = 0.10），并且对血容量没有影响，两组血容量均下降了10%。高血容量组仅1例患者发生需要利尿的肺水肿。
给予补充5%白蛋白溶液以维持CVP值>8 mmHg可防止钠和液体丢失，但对我们基础测量时处于高血容量状态的患者的血容量没有影响。蛛网膜下腔出血后发生的钠利尿可能部分由GFR升高介导。除了作为胶体容量扩张剂外，5%白蛋白溶液还降低GFR并促进蛛网膜下腔出血后的肾钠潴留。这些特性可能会限制维持给定CVP值所需的总液体量，因此可能会将肺水肿的发生率降至最低。
