摘要
目的：探讨大鼠在沙漠干热环境中暑状态下动脉血气变化特点，为临床救治提供实验依据。方法成年雄性SD大鼠48只，麻醉后按随机数字表法分成沙漠干热环境轻、中、重度中暑组及其相应对照组共6组，每组8只。将大鼠置于模拟沙漠干热环境人工实验舱（温度41℃、湿度10%）内分别滞留约70、110、145 min建立沙漠干热环境轻、中、重度中暑模型；各对照组大鼠置于常温环境中至相应时间点。取各组大鼠腹主动脉血，采用便携式血气分析仪进行血气分析，并检测电解质。结果①轻度中暑组动脉血二氧化碳分压（PaCO2）升高达（45.64±8.19） mmHg（1 mmHg＝0.133 kPa），动脉血氧饱和度（SaO2）下降至0.84±0.08，pH值下降至7.36±0.11，说明该组大鼠存在呼吸性酸碱失衡；中度中暑组细胞外液剩余碱（BEecf）下降至-3.00（1.50）mmol/L、碳酸氢根离子（HCO3-）下降至（19.39±1.89）mmol/L，pH值下降至7.21±0.07，说明该组大鼠出现了代谢性酸碱失衡；重度中暑组各指标逐渐加重，且与轻度和中度中暑组之间比较差异均有统计学意义（PaCO2：F＝6.537、P＝0.006，SaO2：F＝5.174、P＝0.015，pH值：F＝10.736、P＝0.001，BEecf：χ2＝16.021、P＝0.000，HCO3-：F＝5.612，P＝0.011），说明该组大鼠存在明显的呼吸性酸中毒合并代谢性酸中毒，出现了严重的混合型酸碱失衡。②与各自对照组比较，中度中暑组血红蛋白（Hb）明显升高（g/L：15.31±1.84比13.28±0.94，t＝2.791，P＝0.014）；重度中暑组Hb、红细胞比容（HCT）均明显升高〔Hb（g/L）：16.59±2.52比13.42±1.15，t＝3.224，P＝0.006；HCT：（53.50±6.63）%比（45.50±4.47）%，t＝2.828，P＝0.013〕，说明从轻度至重度中暑阶段大鼠脱水程度逐渐加重。③轻度中暑组血钠正常（t＝0.665，P＝0.517），血钾轻度降低（t＝-2.526，P＝0.024）；中度中暑组血钠明显升高（t＝2.162，P＝0.048），血钾明显降低（t＝-5.458，P＝0.000）；重度中暑组血钠明显降低（U＝12.500，P＝0.038），以低钾为主，部分大鼠明显高钾（U＝19.500，P＝0.195）。结论沙漠干热环境下中暑大鼠出现了酸中毒、电解质紊乱、呼吸衰竭、脱水等改变。提示在治疗时，轻度至中度中暑阶段应以纠正呼吸性酸中毒为主，同时防治代谢性酸中毒，警惕脱水及电解质紊乱的发展；中度至重度中暑阶段应在纠正呼吸性酸中毒的同时，积极防治并纠正逐渐加重的代谢性酸中毒、脱水及电解质紊乱。
ObjectiveTo investigate the changes in characteristics of blood gas analysis of heatstroke rats residing in dry-heat environment of desert, and to provide a theoretical reference for its treatment in clinic.Methods Forty-eight male Sprague-Dawley （SD） adult rats under anesthesia were divided into six groups by random number table, with 8 rats in each group： namely mild, moderate, severe heatstroke groups and their corresponding control groups. The rats were placed in an artificial chamber with simulated desert dry-heat environment （temperature 41℃, humidity 10%） for about 70, 110, 145 minutes, respectively, to reproduce mild, moderate, severe heatstroke models. The rats in control groups were placed in a normothermic environment for corresponding duration. Abdominal aorta blood of each group was collected for blood gas analysis, and electrolytes were determined by a portable blood gas analyzer.Results① Arterial partial pressure of carbon dioxide （PaCO2） in mild heatstroke group was increased to （45.64±8.19） mmHg （1 mmHg = 0.133 kPa）, arterial oxygen saturation （SaO2） was decreased to 0.84±0.08, pH value was lowered to 7.36±0.11, showing that respiratory acid-base imbalance was resulted. Base excess of extracellular fluid （BEecf） in moderate heatstroke group was decreased to （-3.00±0.76） mmol/L, HCO3- was decreased to （19.39±1.89） mmol/L, and pH value was lowered to 7.21±0.07, indicating that metabolic acid-base imbalance was aggravated gradually. The changes in parameters in severe heatstroke group gradually became more serious, and a significant difference was found as compared with those of mild and moderate heatstroke groups （PaCO2：F = 6.537,P = 0.006; SaO2：F = 5.174,P = 0.015; pH value：F = 10.736,P = 0.001;BEecf：F = 67.136,P = 0.000; HCO3-：F = 5.612,P = 0.011）, manifesting an obvious combination of respiratory acidosis and metabolic acidosis, and a serious mixed acid-base disturbance was produced.② Compared with corresponding control groups, hemoglobin （Hb） was significantly increased in moderate heatstroke group （g/L： 15.31±1.84 vs. 13.28±0.94,t = 2.791,P = 0.014）, Hb and hematocrit （HCT） in severe heatstroke group were significantly increased [Hb （g/L）： 16.59±2.52 vs. 13.42±1.15,t = 3.224,P = 0.006; HCT： （53.50±6.63）% vs. （45.50±4.47）%,t = 2.828, P = 0.013], showing that the degree of dehydration was aggravated gradually from mild to serious degree.③ Serum sodium content in mild heatstroke group was normal （t = 0.665,P = 0.517）, serum potassium content was lowered significantly （t = -2.526,P = 0.024）; serum sodium content in moderate heatstroke group was increased significantly （t = 2.162,P = 0.048）, serum potassium content was lowered significantly （t = -5.458,P = 0.000）; and serum sodium content in severe heatstroke group rose obviously （U = 12.500,P = 0.038）, and most of the rats showed hypokalemia, with a small proportion of rats showed obvious hyperkalemia （U = 19.500,P = 0.195）.ConclusionsAcidosis, electrolyte disturbance, respiratory failure and dehydration in heatstroke occurred in dry-heat environment of desert. It indicates that resuscitation should focus on correction of respiratory acidosis, with simultaneous correction of metabolic acidosis, and one should be alert to correct dehydration and electrolyte disturbance. During the moderate phase and the serious phase, correction of aggravated metabolic acidosis should be reinforced, and the prevention and treatment of the severe dehydration and electrolyte disturbance should be undertaken actively.
出处
《中华危重病急救医学》
CAS
CSCD
北大核心
2015年第8期653-657,共5页
Chinese Critical Care Medicine
基金
军队临床高新技术重大项目（2010gxjs016）
关键词
中暑
沙漠干热环境
血气分析
酸中毒
脱水
呼吸衰竭
电解质紊乱
Heatstroke
Dry-heat environment of desert
Blood gas analysis
Acidosis
Dehydration
Respiratory failure
Electrolyte disturbance
