Reduced intrathoracic blood volume and left and right ventricular dimensions in patients with severe emphysema: an MRI study

BACKGROUND: Left ventricular (LV) filling is impaired in patients with severe emphysema manifesting in small end-diastolic dimensions. We hypothesized that the hyperinflated lungs of these patients with high intrinsic positive end-expiratory pressure will decrease intrathoracic blood volume (ITBV) and ventricular preload. We therefore measured ITBV, and LV and right ventricular (RV) dimensions and function using MRI techniques in patients with severe emphysema. METHODS: Patients with severe emphysema (n = 13) and matched healthy volunteers (n = 11) were included. The magnetic resonance (MR) examination consisted of three parts: (1) evaluation of RV and LV dimensions and function and interventricular septum curvature using cine MRI; (2) quantification of aortic flow using MR phase velocity mapping; and (3) calculation of the cardiopulmonary peak transit time (PTT) from the pulmonary artery to the ascending aorta using contrast-enhanced, time-resolved, two-dimensional MR angiography. RESULTS: There were no differences between the groups regarding age, height, or weight. In the emphysema patients, ITBV index (- 35%), LV end-diastolic volume index (LVEDVI) [- 21%], RV end-diastolic volume index (- 20%), cardiac index (- 22%), and stroke volume index (SVI) [- 40%] were lower compared to control subjects. LV and RV end-systolic volumes, LV wall mass, septal curvature, and PTT did not differ between the groups. LVEDVI (r = 0.83) as well as SVI (r = 0.82) correlated closely to ITBV index. SVI correlated closely to LVEDVI (r = 0.84). CONCLUSIONS: LV and RV performance is impaired in patients with severe emphysema because of small end-diastolic dimensions. One possible explanation for the decreased biventricular preload in these patients is intrathoracic hypovolemia caused by hyperinflated lungs.     

不同潮气量对机械通气患者CVP、ITBV、CI等参数的影响

：[目的]比较在机械通气过程中,不同的潮气量、通气模式（BIPAP与SIMV）对患者CVP、ITBV、CI等参数的影响.[方法]选取24例因各种原因需行有创机械通气和PICCO监测的患者,根据CI分为心功能正常组和心功能低下组.在BIPAP模式下,调整吸气压使VT分别维持于6、10、15 ml/kg,其他呼吸机支持条件不变,呼吸机模式改为SIMV后,分别调节相同VT水平,以上各种条件维持20 min后测量呼吸力学及血流动力学指标.实验过程中以上支持条件随机选择进行.[结果]在心功能正常组,两种呼吸模式下随潮气量增加CI,ITBVI降低,Pmean及PEEPi增加均无明显差异（P值分别为0.067,0.124,0.110,0.187）.在心功能低下组,CI,ITBVI在BIPAP条件下降显著（P=0.036,0.021）,在两种呼吸模式下,随潮气量增加CI、ITBVI明显下降,Pmean,PEEPi明显增加;sVRI在15 ml/kg与6ml/kg组间有统计学差异,两种模式CVP、HR均无明显变化.[结论]两种模式随着潮气量水平的升高,CI及ITBVI均明显下降,尤以衰竭心脏者为甚.CVP则无明显变化.因此,在机械通气应用PICCO评估容量参数中,应考虑心功能及潮气量对CI、ITBVI的影响.     

Extravascular lung water indexed or not to predicted body weight is a predictor of mortality in septic shock patients

Purpose

The purpose was to investigate whether extravascular lung water (EVLW) indexed to actual body weight (EVLWa) is an independent predictor of mortality in patients with septic shock, to determine the relationship between EVLWa and other markers of lung injury, and to test if indexing EVLW with predicted body weight (EVLWp) strengthens its predictive power.

Methods

Extravascular lung water, pulmonary vascular permeability index, and other markers of lung injury were measured prospectively in 55 patients with septic shock for 3 days.

Results

At day 1, EVLWa, EVLWp, and pulmonary vascular permeability index were not significantly different between survivors and nonsurvivors. However, in parallel to the course of septic shock, these variables decreased only in the survivors and remained elevated in the nonsurvivors, reaching intergroup difference by day 3. In multiple logistic regression analysis, both EVLWa and EVLWp (at day 3) were predictors of mortality with an odds ratio of 2 (95% confidence interval, 1.12-3.7) and 1.7 (95% confidence interval, 1.1-2.5) per SD increase, respectively. The receiver operating characteristic curve analysis showed that EVLWp did not improve the discriminative power of EVLW to predict mortality. Extravascular lung water indexed to actual body weight correlated with lung injury score and with the ratio of arterial oxygen partial pressure to inspired oxygen fraction but not with static respiratory compliance. Indexing EVLW to predicted body weight did not ameliorate these correlations.

Conclusions

Extravascular lung water indexed or not to predicted body weight is an independent predictor of mortality in patients with septic shock. Repeated measurements of EVLW indexes over time, rather than a too-early measurement, seem to be more appropriate for predicting outcome.     

以CI、ITBVI、EVLWI为目标导向液体治疗在老年患者重大手术中的应用研究

目的：观察以心指数（CI）、胸腔内血容量指数（ITBVI）、血管外肺水指数（EVLWI）为目标导向的液体管理策略对老年重大手术后转归的影响。方法选取急诊行重大手术的老年患者40例,ASA评分3～4级。将其随机分为研究组和对照组,每组各20例。对照组监测CVP（中央静脉压）指导补液。研究组进行中心静脉置管＋股动脉置管＋PiCCO模块连接,应用PICCO监测血流动力学指标,测定CVP、CI、ITBVI、EVLWI,准确评估患者容量状况,以CI 3．0～5．0 L／min／m2, ITBVI 800～1000 mL／m2,EV－LWI 3．0～7．0 mL／kg为参考值,进行目标导向液体治疗。术中根据CI、ITBVI、EVLWI动态变化调整补液,监测患者心率（ HR）、平均动脉压（ MAP）、尿量、中心静脉血氧饱和度（ ScvO2）、乳酸、肾功能等指标。观察患者术后休克改善情况及呼吸机撤除时间,以及急性肺水肿发生率、急性肾功能不全发生率、死亡率变化。结果研究组患者组织灌注改善,休克改善明显好转,尿量明显增加（P＜0．05）,中心静脉血氧饱和度明显增加（P＜0．05）,血乳酸浓度明显降低（P＜0．05）,急性肺水肿、急性肾功能不全发生率明显低于对照组（ P＜0．05）,死亡率低于对照组（ P＜0．05）。结论以CI、ITBVI、EVLWI为目标导向液体治疗,能有效优化老年重大手术患者的心脏前负荷,提高心输出量,保证微循环灌注,维持机体氧供需平衡,减少并发症发生,降低死亡率。     

PICCO技术在多发伤患者指导液体复苏中的临床应用

目的探讨胸腔内血容量指数（ITBVI）、全心舒张末期容量指数（GEDVI）在多发伤患者容量状态评估中的意义。方法选择26例因多发伤入住ICU的患者,通过PICCO（pulse-indicated conitinuous cardiacoutput）技术（PULSION公司,德国）即经肺热稀释方法和脉搏轮廓分析法监测MAP、CI、SI、SV、EVLWI、ITBVI、GEDVI,记录液体复苏前后的上述指标。同时,监测复苏前、复苏24h后动脉血气分析,记录每次的乳酸及碱剩余值。结果复苏前与复苏终点相比,ITBVI、GEDVI与SI有显著相关性,r分别为0．783、0．774（P〈0．01）;HR与SI似呈负相关,r=-0．309（P〉O．05）;CVP、MAP与SI相关系数r分别为0．104、-0．025（P〉0．05）,相关性较差;复苏后的胸腔内血容量变化（AITBVI）与每搏输出量指数变化（ASI）有显著相关性,r=0．654（P〈O．01）;全心舒张末期总容量指数变化（AGEDVI）与ASI,显著正相关,r=0．558（P〈0．05）;而ACVP、AHR、AMAP与ASI相关系数r分别为-0．042、-0．382、-0．382（P〉O．05）．相关性较差。存活组与死亡组相比,液体复苏前乳酸及碱剩余水平差异无统计学意义（P〉0．05）,液体复苏24h后,死亡组乳酸及碱剩余水平显著高于存活组（P〈0．01）;存活组液体复苏24h后乳酸及碱剩余水平明显低于复苏前（P〈O．01）,死亡组液体复苏前后乳酸及碱剩余水平差异无统计学意义（P〉0．05）。结论ITBVI、GEDVI及其容量复苏后的变化能准确、可靠地评估患者容量状态,对多发伤患者的液体管理具有重要价值。     

胸腔内血容量指数和血管外肺水在创伤性ARDS患者液体管理中的应用

目的 探讨胸腔内血容量指数(ITBVI)及血管外肺水(EVLW)在指导创伤性ARDS患者液体管理中的应用价值,从而探寻ARDS患者的最佳液体管理策略.方法 选取2011年5月～2012年5月符合纳入标准的创伤性ARDS患者57例为研究对象,随机分为限制性液体管理组和开放性液体管理组.记录SOFA评分、氧合指数以及7d和28 d生存率为主要终点,以机械通气时间、ICU住院时间为次要终点进行评价.结果 限制性液体管理组患者在治疗后36 h较开放性液体管理组SOFA评分明显降低,P=0.037,ICU住院时间及机械通气时间明显缩短,P＜0.05,两组患者病死率差异无统计学意义,P＞0.05;治疗前后不同时间氧合指数之间差异有统计学意义,F =60.232,P=0.000;两组患者氧合指数组内、组间比较差异有统计学意义,P ＜0.05.结论 对于创伤性ARDS患者,联合应用ITBVI和EVLW为液体管理目标,精准地进行限制性液体管理能明显改善氧合指数,缩短机械通气时间、ICU住院时间,具有积极的临床意义.     

Aerosolized salbutamol accelerates the resolution of pulmonary edema after lung resection

BACKGROUND: Ischemia-reperfusion injuries, fluid overload, and cardiac insufficiency may all contribute to alveolar and interstitial lung edema. We hypothesized that aerosolized salbutamol would reduce extravascular lung water and improve oxygenation after lung resection by stimulating epithelial fluid clearance and cardiovascular function. DESIGN: Blinded, randomized, cross-over trial. METHODS: We selected 24 patients with risk factors for lung edema. Aerosolized drugs (salbutamol, 5 mg; vs ipratropium, 0.5 mg) were administered on two consecutive trials, with a 6-h washout period, on the day of surgery (postoperative day [POD]-0) as well as on POD-1. Before and 50 min after the end of drug administration, we determined the oxygenation index (Pao(2)/fraction of inspired oxygen [Fio(2)] ratio), the extravascular lung water index (EVLWI), the pulmonary vascular permeability index (PVPI), and the cardiac index (CI) using the single-indicator thermal dilution technique. RESULTS: Complete data were obtained in 21 patients. On POD-0, the EVLWI was increased compared with preoperative values (13.0 +/- 3.8 vs 9.1 +/- 4.4, p < 0.001); salbutamol treatment induced significant increases in Pao(2)/Fio(2) ratio (+ 25 +/- 13%) that were associated with decreases in EVLWI (- 18 +/- 10%, p < 0.05) and in PVPI (- 19 +/- 10%, p < 0.05) along with increased CI (+ 23 +/- 11%, p < 0.05). On POD-1, repeated nebulization of salbutamol induced significant increases in Pao(2)/Fio(2) ratio and CI (+ 22 +/- 10% and 19 +/- 11%, respectively), whereas both EVLWI and PVPI remained unchanged. Nebulization of ipratropium bromide did not produce significant hemodynamic and respiratory changes on POD-0 and POD-1. CONCLUSIONS: Aerosolized salbutamol accelerates the resolution of lung edema, improves blood oxygenation, and stimulated cardiovascular function after lung resection in high-risk patients. TRIAL REGISTRATION: This protocol trial (CER03-160) has been registered at (Clinicaltrials.gov) under NCT00498251.     

Risk factors and the associated limit values for abnormal elevation of extravascular lung water in severely burned adults

BackgroundIncreased extravascular lung water (EVLW) correlates with pulmonary morbidity and mortality in critical illness. The extravascular lung water index (EVLWI), which reflects the degree of EVLW in an individual, increases in the fluid reabsorption stage rather than the initial resuscitation stage in severe burn cases. While many factors contribute to EVLWI variation, the risk factors contributing to its abnormal elevation in severe burns remain unclear. The aim of this study was to identify the risk factors and associated limit values for abnormal elevation of EVLWI during the fluid reabsorption stage in a cohort of severely burned adults.MethodThis prospective, single-center study included only adults with burn sizes ≥ 50% of the total body surface area (TBSA) who were admitted within 24 h after burn. Demographic data were collected, and transpulmonary thermodilution (TPTD) measurements and blood biochemistry tests were performed upon admission and up to day (PBD) 9. Risk factors for abnormal EVLWI were analyzed by logistic regression. Receiver operating characteristic (ROC) curves were constructed to determine the optimal cut-offs for each risk factor.ResultsSeventy-two patients were ultimately enrolled, with a mean age of 40.3 years and mean burn size of 69.4% TBSA. EVLWI began to abnormally increase (>7 ml/kg) on day 3 and up to PBD 9, indicating that a supranormal EVLWI developed in the fluid reabsorption stage. Several relevant factors were considered, including patient age, burn size, intrathoracic blood volume index (ITBVI), pulmonary vascular permeability index (PVPI), cardiac index (CI), systemic vascular resistance index (SVRI), serum albumin, time of first excision and grafting, and number of operations and daily fluid administration. Among these factors, we found that only burn size and ITBVI were significantly correlated with EVLWI variation and were further identified as the independent risk factors for EVLWI abnormality. ROC analysis showed that the limits for predicting a supranormal EVLWI during the fluid reabsorption stage were 65.5% TBSA for burn size and 845 ml/m² for ITBVI. Patients with burn sizes or ITBVIs higher than the limit showed significantly longer mechanical ventilation time and substantially higher occurrences of acute respiratory distress syndrome (ARDS) and pneumonia within two weeks after burn.ConclusionsBurn size and ITBVI are the independent risk factors for EVLWI abnormality during the fluid reabsorption stage in severely burned adults. The limit values for predicting a supranormal EVLWI in those patients are 65.5% TBSA for burn size and 845 ml/m² for ITBVI.     

PICCO监测下脓毒症休克患者复苏实施时间与预后的关系

目的 观察并评估脓毒症休克患者在脉搏指示连续心排血量(PICCO)监测指导下实施液体复苏的不同达标时间对预后的影响。方法 采用回顾性研究的方法,根据PICCO监测的指标即胸腔内血容量指数达到850~1 000 mL/m²时间的不同分为0~6 h达标组和6~12 h达标组。记录两组患者入院后6 h、12 h、24 h和48 h的血气分析、乳酸、感染相关的器官衰竭评分(即SOFA评分)、ICU住院天数、带机时间等,并记录7天、28天病死率。结果 治疗24 h后0~6 h达标组乳酸及SOFA评分明显低于6~12 h达标组,并且28天病死率明显降低。0~6 h达标组患者较6~12 h达标组的带机时间缩短、ICU住院天数减少,7天病死率有所减少,但差异无统计学意义。两组患者治疗后的氧合指数、乳酸等指标均较入院时好转。结论 在PICCO监测指导下对脓毒症休克患者实施液体复苏治疗,6 h达标较12 h达标可明显降低SOFA评分及28天病死率。6 h与12 h使ITBVI达到850~1 000 mL/m²均可改善患者预后。     

早期目标指导治疗达标后不同胸腔内血容量指数指导液体管理对脓毒性休克患者心肺功能的影响

目的探讨脓毒性休克患者早期目标指导治疗(EGDT)达标后在脉搏指示连续心输出量监测技术(PiCCO)测定的胸腔内血容量指数(ITBVI)指导下采取不同液体管理方式对患者心肺功能的影响。方法选择2014年7月~2016年6月入住我院重症医学科,符合纳入标准的脓毒性休克患者65例,按EGDT方案复苏,同时在入科后6 h内开始PiCCO监测,达标后随机分为液体限制组和液体非限制组,并采集病例相关数据。动态检测并比较两组患者入科后不同时段液体出入量、胸腔内血容量指数(ITBVI)、心输出量指数(CI)、血管外肺水指数(EVLWI)、肺血管通透性指数(PVPI)、血清B型钠尿肽(BNP)等指标。记录并比较两组患者机械通气时间、住ICU时间等。结果入科后24 h、48 h、72 h、96 h、120 h,两组间液体入量、每日液体平衡量(入量-出量)、ITBVI、EVLWI、BNP比较差异有统计学意义(P0.05),而CI、PVPI比较差异无统计学意义(P0.05)。液体非限制组的EVLWI与ITBVI、EVLWI与BNP均成正相关(P0.05)。液体限制组使用呼吸机时间、住ICU时间均少于液体非限制组(P0.05)。结论利用略低于正常的ITBVI指导EGDT达标后限制性液体管理,可改善脓毒性休克患者心肺功能,减少肺水产生,缩短机械通气时间和住ICU时间。