婴幼儿体外循环围术期胶体渗透压的变化

Perioperative Changes of Colloid Osmotic Pressure in Infants with Extracorporeal Circulation

目的探讨10 kg以下婴幼儿先天性心脏病体外循环(Extracorporeal c ircu lation,ECC)围术期胶体渗透压(COP)的变化规律以及与肺功能变化的关系。方法20例体重小于10 kg先天性心脏病手术患儿,ECC含血浆预充;测定围术期各个时点的COP值,动脉血气分析观察ECC前后肺换气功能的呼吸指数(R I)、氧合指数(O I)的变化,并通过肺容量-压力曲线观察ECC前后达因(Cdyn)、曲线(Raw)、峰值(Peak)的变化。结果血浆COP在ECC中10 m in[(16.25±2.12)mmHg]和30 m in[(16.72±1.47)mmHg]时较麻醉诱导后[(23.73±2.94)mmHg]有明显下降(P<0.05),而超滤后COP[(28.41±4.12)mmHg]迅速上升,较诱导后有明显的差异(P<0.05),并持续到ECC后5 h仍未下降;R I值在ECC后1 h(6.78±2.20)较ECC前(3.55±1.82)有明显的上升(P<0.05);O I值(336.91±62.53)较ECC前(436.59±75.32)有明显的下降(P<0.05);但ECC中COP的下降率与R I的上升率(r2=0.0169,P>0.05)和O I的下降率(r2=0.1225,P>0.05)之间无直线相关;ECC前后Cdyn,Raw,Peak无明显差异(P>0.05)。结论低体重先天性心脏病幼儿对ECC手术耐受差,血浆预充可以维持ECC中COP不低于16 mmHg,通过改良超滤可以进一步减轻水肿并在转后一定时间仍维持较高的渗透压,而且本实验证明血浆COP轻度降低(不低于16 mmHg)不是术后肺功能的改变的主要原因。

OBJECTIVE To observe the changes of colloid osmotic pressure（COP） during and after extracorporeal cireulation（ECC） in infants less than 10kg. METHODS 20 cases underwent elective ECC surgery for congenital heart disease （CHD） were investigated. The plasma was used as the colloid component of the ECC priming. Seven intervals of blood samples were obtained and COP was assayed perioperatively. Resistance of airway （ Raw）, peak airway pressure （ Peak）, dynamic pulmonary compliance （Cdyn）, respiratory index （RI） and oxygenative index（OI） were monitored or calculated before and after ECC. RESULTS The COP decreased significantly during the ECC （ P 〈 0.05）, then increased rapidly after the ultrafiltration（ P 〈0.05） and kept elevating at first 5 hours after ECC. After 1hour of ECC, RI increased and OI decreased significantly （ P 〈0.05）, compared with those after the induction of anesthesia. However,the decrease of COP was not related to the increase of RI （ x^2 = 0. 0169, P 〉 0. 05） and the decrease of OI （x^2 -0. 1225, P 〉 0.05）. Cdyn, Raw and Peak were not significant difference before and after ECC. CONCLUSION Plasma as the ECC - priming could maintain the COP not less than 16 mmHg. By the ultrafiltmtion,the edema could be alleviated effectively and COP could maintain higher level for a long period after ECC. Moreover, it is testified that the decrease of COP（ 316 mmHg） is not the main influence for postoperative respiratory dysfunction.