Abstract：
OBJECTIVE: Growing evidence shows the complex interaction between lung and kidney in critically ill patients. The renal resistive index (RRI) is a bedside measurement of the resistance of the renal blood flow and it is correlated with kidney injury. The positive end-expiratory pressure (PEEP) level could affect the resistance of renal blood flow, so we assumed that RRI could help to monitoring the changes in renal hemodynamics at different PEEP levels. Our hypothesis was that the RRI at ICU admission could predict the risk of acute kidney injury in mechanical ventilated critically ill patients.
METHODS: We performed a prospective study including 92 patients requiring mechanical ventilation for ≥ 48 h. A RRI ≥ 0.70, was deemed as pathological. RRI was measured within 24 h from ICU admission while applying 5,10 and 15 cmH2O of PEEP in random order (PEEP trial).
RESULTS: Overall, RRI increased from 0.62 ± 0.09 at PEEP 5 to 0.66 ± 0.09 at PEEP 15 (p < 0.001). The mean RRI value during the PEEP trial was able to predict the occurrence of AKI with AUROC = 0.834 [95%CI 0.742-0.927]. Patients exhibiting a RRI ≥ 0.70 were 17/92(18%) at PEEP 5, 28/92(30%) at PEEP 10, 38/92(41%) at PEEP 15, respectively. Thirty-eight patients (41%) exhibited RRI ≥ 0.70 at least once during the PEEP trial. In these patients, AKI occurred in 55% of the cases, versus 13% remaining patients, p < 0.001.
CONCLUSIONS: RRI seems able to predict the risk of AKI in mechanical ventilated patients; further, RRI values are influenced by the PEEP level applied.
BACKGROUND: Clinical gov NCT03969914 Registered 31 May 2019.
METHODS: We performed a prospective study including 92 patients requiring mechanical ventilation for ≥ 48 h. A RRI ≥ 0.70, was deemed as pathological. RRI was measured within 24 h from ICU admission while applying 5,10 and 15 cmH2O of PEEP in random order (PEEP trial).
RESULTS: Overall, RRI increased from 0.62 ± 0.09 at PEEP 5 to 0.66 ± 0.09 at PEEP 15 (p < 0.001). The mean RRI value during the PEEP trial was able to predict the occurrence of AKI with AUROC = 0.834 [95%CI 0.742-0.927]. Patients exhibiting a RRI ≥ 0.70 were 17/92(18%) at PEEP 5, 28/92(30%) at PEEP 10, 38/92(41%) at PEEP 15, respectively. Thirty-eight patients (41%) exhibited RRI ≥ 0.70 at least once during the PEEP trial. In these patients, AKI occurred in 55% of the cases, versus 13% remaining patients, p < 0.001.
CONCLUSIONS: RRI seems able to predict the risk of AKI in mechanical ventilated patients; further, RRI values are influenced by the PEEP level applied.
BACKGROUND: Clinical gov NCT03969914 Registered 31 May 2019.
摘要：
目的：越来越多的证据表明危重患者的肺和肾之间存在复杂的相互作用。肾阻力指数（RRI）是对肾血流阻力的床边测量，与肾损伤相关。呼气末正压(PEEP)水平可影响肾血流阻力,因此,我们假设RRI有助于监测不同PEEP水平下肾脏血流动力学的变化.我们的假设是，ICU入院时的RRI可以预测机械通气危重患者发生急性肾损伤的风险。
方法：我们进行了一项前瞻性研究，包括92例需要机械通气时间≥48h的患者。RRI≥0.70被认为是病理性的。在ICU入院后24小时内测量RRI，同时以随机顺序应用5、10和15cmH2O的PEEP（PEEP试验）。
结果：总体而言，RRI从PEEP5的0.62±0.09增加到PEEP15的0.66±0.09(p<0.001)。PEEP试验期间的平均RRI值能够预测AKI的发生，AUROC=0.834[95CI0.742-0.927]。表现出RRI≥0.70的患者在PEEP5时为17/92（18％），在PEEP10时为28/92（30％），在PEEP15时为38/92（41％）。在PEEP试验期间，38例患者（41%）至少一次表现出RRI≥0.70。在这些患者中,55%的病例发生AKI，与13%的剩余患者相比，p<0.001。
结论：RRI似乎能够预测机械通气患者发生AKI的风险；RRI值受所应用的PEEP水平的影响。
背景：临床政府NCT03969914于2019年5月31日注册。
方法：我们进行了一项前瞻性研究，包括92例需要机械通气时间≥48h的患者。RRI≥0.70被认为是病理性的。在ICU入院后24小时内测量RRI，同时以随机顺序应用5、10和15cmH2O的PEEP（PEEP试验）。
结果：总体而言，RRI从PEEP5的0.62±0.09增加到PEEP15的0.66±0.09(p<0.001)。PEEP试验期间的平均RRI值能够预测AKI的发生，AUROC=0.834[95CI0.742-0.927]。表现出RRI≥0.70的患者在PEEP5时为17/92（18％），在PEEP10时为28/92（30％），在PEEP15时为38/92（41％）。在PEEP试验期间，38例患者（41%）至少一次表现出RRI≥0.70。在这些患者中,55%的病例发生AKI，与13%的剩余患者相比，p<0.001。
结论：RRI似乎能够预测机械通气患者发生AKI的风险；RRI值受所应用的PEEP水平的影响。
背景：临床政府NCT03969914于2019年5月31日注册。
