成人心脏术后常用卧位下中心静脉压差异及压力零点位置研究

Study on the difference of central venous pressure at common positions and the location of pressure zero among adult patients after cardiac surgery

目的探讨成人心脏术后患者3种常用卧位(头高30°、头高30°左侧45°和右侧45°)测量中心静脉压(CVP)的差异及压力零点位置,为临床获取正确监测结果提供参考。方法选择成人心脏术后患者100例,在同一时段分别采用头高30°、头高30°左侧45°和右侧45°三种常用卧位测得CVP,并与平卧位测量值进行比较;当侧卧位时沿标准零点位置上下移动传感器,标记与平卧位CVP值相同时的压力零点胸壁位置,同时记录心率(HR)、平均动脉压(MAP)、呼吸(RR)、血氧饱和度(SpO2)变化。结果头高30°卧位与平卧位时CVP值比较,差异无统计学意义(P>0.05);头高30°左侧45°卧位较平卧位时CVP值低,与平卧位CVP值相同的压力零点位于右侧腋后线与第四肋间交点(-0.15±0.49)cm;头高30°右侧45°卧位较平卧位时CVP值高,与平卧位CVP值相同的压力零点位于右侧腋前线与第四肋间交点(0.18±0.54)cm。3种常用卧位与平卧位时的HR、MAP、RR、SpO2比较差异无统计学意义(均P>0.05)。结论心脏术后成人常用头高30°卧位下测得的CVP存在一定差异,且压力零点位置与平卧位不同。确定成人心脏术后患者临床3种常用卧位测量CVP的差异和压力零点位置的变化,有助于护理人员采取对应措施确保CVP测量值准确。

Objective To explore the difference of central venous pressure（CVP）at three kinds of commonly used positions（head of bed elevation 30 degrees,head of bed elevation 30 degrees left lateral 45 degrees,and head of bed elevation 30 degrees right lateral45degrees）among adult patients after cardiac surgery,to identify the location of pressure zero,and to provide reference for clinical monitoring.Methods Totally,100 adult patients after cardiac surgery,were placed in positions（head of bed elevation 30 degrees,head of bed elevation 30 degrees left lateral 45 degrees,and head of bed elevation 30 degrees right lateral 45degrees）sequentially,and CVP results at the 3positions were measured and compared with CVP values measured at supine position.When patients were placed at lateral positions,researchers moved the mobile sensor above or below the zero reference points,marked the zero pressure points against thoracic wall when CVP reached the same values as at supine position.Patients′heart rate（HR）,mean arterial pressure（map）,respiratory rate（RR）,oxygen saturation（SpO2）change were recorded.Results CVP values measured at head of bed elevation 30 degrees had no significant difference with those measured at supine position（P〈0.05）.CVP values at head of bed elevation 30 degrees left lateral 45 degrees were lower than those at supine,and when the CVP reached the supine readings,the zero pressure point was located（-0.15 ±0.49）cm at the point of intersection of the right anterior axillary line and the fourth intercostal space.CVP values at head of bed elevation 30 degrees right lateral 45 degrees were higher than those at supine,and when the CVP reached the supine readings,the zero pressure point lay（0.18±0.54）cm at the point of intersection of the right anterior axillary line and the fourth intercostal space.No difference significances were found between HR,MAP,RR,SpO2 values measured at the 3positions and those measure at supine（P〈0.05 for all）.Conclusion After cardiac surgery,CVP values of adult patients measured at head of bed elevation 30 degrees presents differences with those measured at supine,and the zero pressure points are different from the zero reference point at supine position.Understanding of the differences is helpful for nurses to take corresponding measures to ensure the accuracy of CVP measurement.