Fluid administration has traditionally focused on preload responsiveness (PR). However, preventing fluid intolerance, particularly due to systemic venous congestion (VC), is equally important. This study evaluated the incidence and predictability of VC following a 7 ml/kg crystalloid infusion in fluid-tolerant preload-responders and its association with adverse outcomes. This single-center, prospective, observational study (May 2023–July 2024) included 40 consecutive patients who were mechanically ventilated within 6 h of intensive care unit (ICU) admission after elective open-heart surgery and had acute circulatory failure. Patients were eligible if they were both fluid-tolerant and preload-responsive. PR was defined as a ≥ 12% increase in left-ventricular outflow tract velocity time integral (LVOT-VTI) 1 min after a passive leg raising (PLR) test. VC was defined by a portal vein pulsatility index (PVPI) ≥ 50%. Patients received a 7 ml/kg Ringer’s Lactate infusion over 10 min. The primary outcome was the incidence of VC 2 min post-infusion (early-VC). Secondary outcomes included VC at 20 min, the incidence of acute kidney injury (AKI) and severe AKI at 7 days, and ICU length of stay (LOS). 45% of patients developed early-VC, with VC persisting in only 5% at 20 min. One-third of patients developed AKI, with 17.5% progressing to severe AKI. The median ICU LOS was 4 days. Patients with early-VC had significantly higher central venous pressure, lower mean perfusion pressure, worse baseline right ventricular function, and a higher incidence of severe AKI. While LVOT-VTI returned to baseline by 20 min in both groups, PVPI remained elevated in early-VC patients (p < 0.001). The LVOT-VTI versus PVPI regression line showed similar slopes (p = 0.755) but different intercepts (p < 0.001), indicating that, despite fluid tolerance and PR at baseline, early-VC patients had reduced right ventricular diastolic reserve (RVDR). Post-PLR PVPI predicted early-VC with an area under the curve of 0.998, using a threshold of 44.3% (p < 0.001). Post-PLR PVPI effectively predicts fluid-induced early-VC in fluid-tolerant preload-responders, identifying those with poor RVDR. Its use can guide fluid management in cardiac surgery patients, helping to prevent unnecessary fluid administration and associated complications. Trial Registration: NCT06440772. Registered 30 May 2024. Retrospectively registered.

中文翻译：

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心脏手术后最初耐液体前负荷反应者液体负荷激发后全身性静脉充血的发生率、可预测性和结果：一项初步试验


液体给药传统上侧重于前负荷反应性 （PR）。然而，预防液体不耐受，特别是由于全身静脉充血 （VC） 引起的液体不耐受同样重要。本研究评估了耐液体前负荷反应者输注 7 ml/kg 晶体液后 VC 的发生率和可预测性及其与不良结局的相关性。这项单中心、前瞻性、观察性研究（2023 年 5 月至 2024 年 7 月）包括 40 例连续患者，这些患者在择期心脏直视手术后重症监护病房 （ICU） 入院后 6 小时内接受了机械通气，并患有急性循环衰竭。如果患者既耐液体又对前负荷有反应，则他们符合条件。PR 定义为被动抬腿 （PLR） 试验后 1 min 左心室流出道流出道速度时间积分 （LVOT-VTI） ≥增加 12%。VC 由门静脉搏动指数 （PVPI） 定义≥ 50%。患者在 10 分钟内接受 7 ml/kg 林格氏乳酸输注。主要结局是输注后 2 分钟 （early-VC） 的 VC 发生率。次要结局包括 20 分钟 VC 、 7 天急性肾损伤 （AKI） 和严重 AKI 的发生率以及 ICU 住院时间 （LOS）。45% 的患者发生早期 VC，其中 20 分钟时仅 5% 的 VC 持续存在。1/3 的患者发展为 AKI，17.5% 进展为重度 AKI。中位 ICU LOS 为 4 天。早期 VC 患者的中心静脉压显著升高，平均灌注压降低，基线右心室功能较差，严重 AKI 的发生率较高。虽然两组的 LVOT-VTI 在 20 min 时都恢复到基线水平，但早期 VC 患者的 PVPI 仍然升高 （p < 0.001）。LVOT-VTI 与 PVPI 回归线显示相似的斜率 （p = 0.755） 但截距不同 （p < 0.001），表明尽管基线时有液体耐量和 PR，但早期 VC 患者的右心室舒张储备 （RVDR） 降低。PLR 后 PVPI 预测早期 VC，曲线下面积为 0.998，阈值为 44.3% （p < 0.001）。PLR 后 PVPI 可有效预测耐液体前负荷反应者中液体诱导的早期 VC，识别 RVDR 较差的患者。它的使用可以指导心脏手术患者的液体管理，有助于防止不必要的液体给药和相关并发症。试用注册：NCT06440772。2024 年 5 月 30 日注册。回顾性注册。