呼吸末正压通气及特伦德伦伯体位对肥胖患者右侧颈内静脉的影响

Influence of the positive endexpiratory pressure and Trendelenburg position on the right jugular vein in obese patients

目的 颈内静脉穿刺置管对肥胖患者而言存在一定的困难和挑战.设想呼吸末正压通气（PEEP）及特伦德伦伯体位是否能增加肥胖患者的右侧颈内静脉的横截面积.方法 选取40例围手术期患者,男19例,女21例,年龄43-69岁,体质量指数（BMI）≥30 kg/m^2,美国麻醉医师协会（ASA）分级Ⅰ-Ⅲ级,40例患者于麻醉后行气管插管进行机械通气后处于仰卧位水平,设置PEEP为0、5、10 cmH2O（1 cmH2O=0.098 kPa）时,另外设置头低位20°特伦德伦伯体位时,超声分别于环状软骨水平测量右侧颈内静脉的横截面积、横径、前后直径.结果 右侧颈内静脉的横截面积、横径、前后直径于PEEP为5、10 cmH2O时较PEEP为0 cmH2O时有所增加,差异有统计学意义（P〈0.05）,其中有6例患者设置PEEP为10 cmH2O后,因血压低于90/60 mmHg（1 mmHg=0.133 kPa）而排除;右侧颈内静脉的横截面积、横径、前后直径于头低位20°特伦德伦伯体位时较PEEP为0、5、10 cmH2O时有所增加[横截面积：（1.38 ± 0.34）cm^2比（0.73 ± 0.30）、（0.97 ± 0.26）和（1.15 ± 0.30）cm^2;横径：（1.50 ± 0.30）cm比（1.00 ± 0.26）、（1.18 ± 0.27）和（1.29 ± 0.26）cm;前后直径：（1.01 ± 0.16）cm比（0.57 ± 0.16）、（0.75 ± 0.18）和（0.84 ± 0.16）cm],差异有统计学意义（P〈0.05）;其中头低位20°特伦德伦伯体位时,右侧颈内静脉横截面积最大为（1.38 ± 0.34）cm^2.结论 PEEP及头低位20°特伦德伦伯体位的应用可增加肥胖患者右侧颈内静脉的横截面积、横径及前后直径.设置头低位20°特伦德伦伯体位时患者右侧颈内静脉横截面积、横径及前后直径最大,PEEP为10 cmH2O时其次;设置头低位20°特伦德伦伯体位时患者气道压最高,设置PEEP为10 cmH2O时有部分患者出现血压低于90/60 mmHg;就气道压和血流动力学稳定而言,设置PEEP为5 cmH2O时更适合肥胖患者颈内静脉穿刺.

Objective The internal jugular vein puncture catheter had some difficulties and challenges for obese patients.Whether positive end expiratory pressure and Trendelenburg position will increase the cross-sectional area of the right internal jugular vein in obese patients. Methods Forty patients were selected for perioperative period.Male-to-female ratio was 19：21;age ranged from 43 to 69 years. ASA wasⅠ-Ⅲ, and BMI was ≥ 30 kg/m^2. After induction of general anesethesia and end intubation,the patients were placed in a supine position on a level bed with the head turning to the left 20°.The transverse diameter, anter-posterior diameter and the cross-sectional area of the right internal jugular vein were measured incrementally from the lowest to the highest with PEEP 0,5 and 10 cmH2O （1 cmH2O=0.098 kPa） and the head-down position angle of 20°. Ultrasound was used to measure and record the transverse diameter, anter-posterior diameter and the cross-sectional area of the right internal jugular vein at the level of the cricoid cartilage. Results All PEEP levels increased the transverse diameter, anter-posterior diameter and the cross-sectional area of the right internal jugular vein compared with the control： （1.38 ± 0.34） cm^2vs. （0.73 ± 0.30）, （0.97 ± 0.26） and （1.15 ± 0.30） cm^2;（1.50 ± 0.30）cm vs.（1.00 ± 0.26）,（1.18 ± 0.27）and（1.29 ± 0.26）cm;（1.01 ± 0.16）cm vs.（0.57 ± 0.16）, （0.75 ± 0.18）and（0.84 ± 0.16）cm,P〈0.05.Six patients were excluded because the blood pressure was below 90/60 mmHg （1 mmHg=0.133 kPa） after PEEP 10 mmHg was seted. Transverse diameter, anter-posterior diameter and the cross-sectional area of the right internal jugular vein was larger at the head-down position angle 20°compared with that at the PEEP levels.The largest cross-sectional area was （1.38 ± 0.34）cm^2.Conclusions The use of positive end expiratory pressure and Trendelenburg position increases transverse diameter, anter-posterior diameter and the cross-sectional area of the right internal jugular vein in obese patients.Transverse diameter, anter-posterior diameter and the cross-sectional area of the right internal jugular vein is the largest at the head-down position angle 20°, then the PEEP 10 cmH2O.Airway pressure is the largest at the head-down position angle 20°.When we set the PEEP 10 cmH2O, some patients′ blood pressure is below 90/60 mmHg. AS for the airway pressure and hemodynamic instability, we recommend using PEEP 5 cmH2O to facilitate internal jugular venous cannulation in obese patients.