PiCCO技术指导下不同呼气末正压水平对ARDS患者氧合的影响

The effect of different positive end-expiratory pressure levels on oxygenation index under the direction of pulse-indicated continuous cardiac output during treating acute respiratory distress syndrome patients

目的探讨PiCCO技术指导下不同水平的呼气末正压（PEEP）对ARDS机械通气患者氧合的影响。方法选择2009年4月至2012年6月间ARDS患者32例，根据PiCCO监测指标血管外肺水指数（ELWI）高低分两组，≥14mL／kg组和〈14mL／kg组，各16例。每组随机（随机数字法）分成PEEP≥12emil，0和PEEP〈12emil，0（1emil：0=0．098kPa）各8例进行治疗。观察4组患者不同PEEP治疗时0h，24h，72h血管外肺水指数（ELWI）、肺血管通透性指数（PVPI）、氧合指数（PaO：／FiO：）的变化。并对血管外肺水指数与氧合指数、血管外肺水指数与肺血管通透性指数及氧合指数与肺血管通透性指数的相关性进行分析。结果①ELWI〈14mL／kg组：PEEP〈12cmH20组24h、72hELWI下降（P=0．0068），72hELWI低于0h、24h，差异均具有统计学意义；PVPI有下降趋势（P=0．0440），72hPVPI低于0h（P〈0．05）；Pa02／Fi02逐渐改善（P=0．0336），72h高于0h（P〈0．05）。PEEP≥12emil，O组24h、72hELWI下降（P=0．0124），72hELWI低于0h（P〈0．05）；PVPI有下降趋势（P=0．0440），72hPVPI低于0h（P〈0．05）；Pa02／Fi02逐渐改善（P=0．0447），72h高于0h（P〈0．05）。两组患者治疗72h氧合指数比较差异无统计学意义（P=0．9889）。②ELWI≥14mL／kg组：PEEP〈12emil20组24h、72hELWI下降P=0．0005），72hELWI低于0h、24h，差异均具有统计学意义；PVPI有下降趋势（P=0．0483），72hPVPI低于0h（P〈0．05）；PaO，／FiO：逐渐改善（P=0．0458），72h高于0h（P〈0．05）。PEEP〉~12emil20组24h、72hELWI下降（P=0．0003），72hELWI低于0h、24h，差异均具有统计学意义；PVPI有下降趋势（P=0．0243），72hPVPI低于0h（P〈0．05）；PaO，／Fi02逐渐改善（P=0．0032），72h高于0h、24h，差异均具有统计学意义。72h氧合指数比较：PEEP≥12emil20组大于PEEP〈12cmH20组（P=0．0465）。③本组32例ARDS患者研究显示Pa02／Fi02与ELWI呈显著负相关（r=-0．6724．t=-4．9754，P=0．0000）；ELWI与PVPI呈显著正相关（r=0．4620，t=2．8536，P=0．0078）；Pa02／Fi02与PVPI之间无显著相关性（r=-0．1763，t=-0．9811，P=0．3344）。结论不同肺水含量的ARDS患者机械通气时，呼气末正压的应用均能改善氧合，72h效果显著。ELWI〈14mL／kg的ARDS患者，高水平PEEP（≥12emilzO）并未额外获益；但ELWII〉14mL／kg的ARDS患者，高水平PEEP（≥12emil。O）能更大限度的改善患者氧合状况。

Objective To investigate the effect of different positive end-expiratory pressure （PEEP） levels on oxygenation index under the direction of PiCCO during treating acute respiratory distress syndrome （ARDS） patients with mechanical ventilation. Methods According to the level of extravascular lung water index （ELWI） shown by PiCCO, thirty-two cases of ARDS patients selected from April 2009 to June 2012 were divided into two groups： ELWI I〉14 mL/kg group （n = 16） and ELWI 〈 14 mL/kg group （n = 16）, Each group was further randomly （random number） allocated to two subgroups according to PEEP levels： PEEP i〉 12 cmH20 （n =8） and PEEP 〈 12 cmH20 （n =8） , to observe the changes of ELWI, pulmonary vascular permeability index （PVPI）, oxygenation index （PaO~/FiO2 ） at 0 h, 24 h, 72 h following different PEEP treatments among four subgroups of patients and analyze the correlation between ELWI and PaO2/ FiO2, ELWI and PVPI, PaO2/FiO2 and PVPI. Results （1）ELWI 〈 14 mL/kg group of patients with ARDS, As the therapy time prolongs, in PEEP 〈 12 cmH20 subgroup, ELWI at 24 h and 72 h obviously decreased （P = 0. 0068） , especially ELWI at 72 h were much lower than those at 0 h and 24 h. Moreover, the PVPI presented a decline （P = 0. 0440） which at 72 h was lower than 0 h （P 〈 0. 05 ） . And PaO2/FiO2 was gradually improved （P = 0. 0336）, the level of which at 72 h was higher than 0 h （ P 〈 0. 05 ）. In PEEP t〉 12 emH20 subgroup, ELWI at 24 h and 72 h markedly decreased （P = 0. 0124）, especially ELWI at 72 h was much lower than that at Oh （P 〈 0. 05）. Moreover, the PVPI showed a downward trend （ P = 0. 0440 ） which at 72 h was lower than Oh （ P 〈 0.05 ）. And PaO2/FiO2 was gradually improved （ P = 0. 0447 ） , the level of which at 72 h was higher than 0 h （ P 〈 0. 05 ）. The oxygenation index at 72 h had no significant difference between these two subgroups as above （P = 0. 9889） . Similarly, in ELWI i〉 14 mL/kg group of patients with ARDS, As the therapy time prolongs, PEEP 〈 12 cmH20 subgroup, the ELWI at 24 h and 72 h obviously decreased （ P = 0. 0005 ） , especially ELWI at 72 h were significantly lower than those at 0 h and 24 h. Moreover, the PVPI presented a decline （P = 0. 0483） which at 72 h was lower than 0 h （ P 〈 0. 05 ）. And PaO2/FiO2 was gradually improved （ P = 0. 0458 ） , the level of which at 72 h was higher than Oh （P 〈0. 05）. In PEEP I〉 12cmH20 subgroup, ELWI at 24 h and 72 h markedly decreased （P =0. 0003） , especially ELWI at 72 h were much lower than those at 0 h and 24 h. Moreover, the PVPI showed a downward trend （P = 0. 0243 ） which at 72 h was lower than 0 h （ P 〈 0. 05 ）. And PaOJFiO2 was gradually improved （P=0.0032）, the level of which at 72 h was higher than 0 h and 24 h （P〈 0. 05）. Compared with PEEP 〈 12 cmH20 subgroup, the oxygenation index at 72 h was obviously elevated in PEEP I〉 12cmH20 subgroup and had significant difference （P = 0. 0465 ）.PaOJFiO2 had a negative correlation with ELWI （r = - 0. 6724. t = - 4. 9754, P = 0. 0000）. And ELWI had a positive correlation with PVPI （r = 0. 4620. t = 2. 8536, P = 0. 0078）. While PaO2/FiO2 had no correlation with PVPI （ r = -0. 1763, t = - 0.9811, P = 0.3344）. Conclusions During mechanical ventilation, PEEP can improve oxygenation of the ARDS patients with different levels of lung water, and the effect is significant at 72 h. The ARDS patients with ELWI 〈 14 mLJkg have not got an extra benefit from high levels of PEEP （ I〉 12 cmH20）. However, high levels of PEEP （ t〉 12 cmH20） can to a greater extent increase the oxygenation index in the ARDS patients with ELWI i〉 14 mL/kg.