Laptook A R, Peterson J, Porter A M
Department of Pediatrics, Southwestern Medical School, Dallas, TX 75235.
J Cereb Blood Flow Metab. 1988 Apr;8(2):193-200. doi: 10.1038/jcbfm.1988.49.
To determine the effects of lactic acidemia versus lactate on CBF, we infused lactic acid, either buffered with NaOH (L + NaOH) or with added NaCl (L + NaCl), to attain similar osmolalities in 18 piglets. CBF (microsphere technique), pH, blood gases, plasma osmolality, and cerebral arteriovenous differences of O2 content and lactic acid concentrations were measured prior to, at 30 min of a lactic acid infusion, and 15 and 90 min after completion of the infusion. Control arterial pH was comparable between groups (7.50 +/- 0.02 vs. 7.49 +/- 0.02, X +/- SE); during and following L + NaCl and L + NaOH, values were (p less than 0.05) 7.09 +/- 0.03, 7.35 +/- 0.02, and 7.46 +/- 0.02 vs. 7.58 +/- 0.03, 7.61 +/- 0.01, and 7.57 +/- 0.03, respectively. PaCO2 remained unchanged and osmolality rose by 15% in both groups during infusions and persisted throughout the study period. For L + NaCl piglets, CBF (ml/min.100 g) rose from 136 +/- 15 to 198 +/- 26 (p less than 0.05) at 30 min of infusion and remained elevated at 201 +/- 25 and 207 +/- 28 at 15 and 90 min following the infusion, respectively. Similarly, for L + NaOH piglets, CBF rose from 130 +/- 25 to 196 +/- 31 (p less than 0.05) with the infusion and was 174 +/- 17 and 166 +/- 21 at 15 and 90 min afterward, respectively. Although lactic acid infusion increases CBF, the associated metabolic acidemia is not responsible for changes in CBF.
为了确定乳酸血症与乳酸对脑血流量（CBF）的影响，我们对18头仔猪输注用氢氧化钠缓冲的乳酸（L + NaOH）或添加氯化钠的乳酸（L + NaCl），以使两组渗透压相似。在输注乳酸前、输注30分钟时以及输注结束后15分钟和90分钟，测量CBF（微球技术）、pH值、血气、血浆渗透压以及脑动静脉氧含量差和乳酸浓度差。两组的对照动脉pH值相当（7.50±0.02对7.49±0.02，X±SE）；在L + NaCl和L + NaOH输注期间及之后，pH值分别为（p<0.05）7.09±0.03、7.35±0.02和7.46±0.02，而对照组分别为7.58±0.03、7.61±0.01和7.57±0.03。两组输注期间PaCO2均保持不变，渗透压均升高15%，且在整个研究期间持续存在。对于L + NaCl组仔猪，输注30分钟时CBF（ml/min·100g）从最初的136±15升至198±26（p<0.05），输注结束后15分钟和9分钟时分别维持在201±25和207±28的较高水平。同样，对于L + NaOH组仔猪，输注时CBF从130±25升至196±31（p<0.05），输注结束后15分钟和90分钟时分别为174±至17和166±21。尽管输注乳酸会增加CBF，但相关的代谢性酸血症并非导致CBF变化的原因。
