摘要
目的观察深昏迷脑死亡和非脑死亡患者传统呼吸暂停试验时严重并发症的发生情况，探索有效的预防措施。方法收集可疑脑死亡病例15例，采用传统呼吸暂停试验．试验前补足前负荷或给予小剂量去甲肾上腺素（NE）维持循环。于试验前、吸纯氧后、脱机4min、脱机6～8min以及重新上机后5min进行动脉血气分析。记录血流动力学参数以及NE用量．试验前及试验结束后测定血乳酸浓度。结果15例患者中，14例呼吸暂停试验结果为阳性．1例阴性。阳性患者脱机后8min内动脉血二氧化碳分压（PaCO2）显著上升[〉60mmHg（1mmHg-0．133kPa），P〈0．01]，pH值下降（P〈0．05）．但动脉血氧分压（PaO2）保持在100mmHg以上；心率、平均动脉压（MAP）轻度下降，但差异无显著性；与基础值比较，平均肺动脉压（PAP）显著升高（P〈0．05）。而试验结果阴性患者脱机后心率加快，血压上升．出现自主呼吸，重新给予机械通气后循环恢复平稳。试验过程中无严重心律失常发生。11例进行呼吸暂停试验的患者给予NE维持循环（NE组），NE泵人剂量[0．10～0．60μg·kg^-1·min^-1．平均（0．23±0．17）μg·kg^-1·min^-1，始终无改变]。余4例患者（无NE组）未用任何血管活性药物。使用或未使用NE的患者MAP、PAP和肺动脉楔压（PAWP）变化趋势基本一致．HR、MAP、PAWP下降，PAP则升高，但两组间比较差异均无显著性。与基础值比较，试验结束时患者血乳酸浓度无明显变化[（1．41±0．05）mmol／L比（1．47±0．07）mmol／L]。结论传统呼吸暂停试验能保证患者良好的氧合状态，对非脑死亡患者引起低血压的风险更小。在补足前负荷基础上，给予小剂量NE进行循环支持治疗，能有效防止脑死亡患者呼吸暂停试验时严重低血压的发生。
Objective To determine the occurrence of severe complications such as hypotension, pulmonary artery hypertension as well as hypercapnia during apnea test in the affirmation of brain death and to investigate the possible effective prophylactic interventions. Methods Conventional apnea test was performed in 15 clinically suspected brain death patients. Stable circulation was achieved by adjusting preload only （n = 4） or combined with titrating norepinephrine （NE, n = 11）. Blood gas was respectively analyzed before apnea test, 10 minutes after 100% fraction of oxygen （FiO2） ventilation, at each 2-minute interval after disconnecting ventilator and 5 minutes after re-ventilation. Piemodynamic parameters and dosage of NE were recorded at the same time points. Plasma concentration of lactate was measured before and at the end of apnea test. Results Spontaneous breath occurred in 1 case among 15 suspected brain death patients. Partial pressure of carbon dioxide （PaCO2） reached higher than 60 mm Pig （1 mm Hg=0. 133 kPa） within 8 minutes in positive apnea test patients （P〈0.01）. pH significantly decreased （P〈0.05）, but partial pressure of oxygen （PaO2） maintained higher than 100 mm Pig during the test. Heart rate （FIR） and mean artery pressure （MAP） slightly lowered （P〉0. 05）, but pulmonary artery pressure （PAP） markedly elevated （P〈0.05） at the end of the test in comparison with their base lines. On the other hand, HR and MAP increased in the negative apnea test case after ventilator disconnection. Severe arrhythmia events did not occur in all the cases. There was no change in the dosage of NE infusion, the range of which was 0.10- 0. 60 μg·kg^-1·min^-1 with the mean level of （0.23±0.17）μg·kg^-1·min^-1. The trend of HR, MAP, PAP and pulmonary arterial wedge pressure （PAWP） alterations was the same in patients no matter whether or not NE was used. HR, MAP and PAWP lowered, while PAP enhanced. Plasma lactate level was not significantly altered at the
出处
《中国危重病急救医学》
CAS
CSCD
北大核心
2006年第5期260-263,共4页
Chinese Critical Care Medicine
基金
国家卫生部指令性课题(WKJ200320027)
