Purpose

Fluid boluses (FB) are often used in post-cardiac arrest (CA) patients with haemodynamic instability. Although FB may improve cardiac output (CO) and mean arterial pressure (MAP), FB may also increase central venous pressure (CVP), reduce arterial PaO₂, dilute haemoglobin and cause interstitial oedema. The aim of the present study was to investigate the net effect of FB administration on cerebral tissue oxygenation saturation (SctO₂) in post-CA patients.

Methods

Pre-planned sub-study of the Neuroprotect post-CA trial (NCT02541591). Patients with anticipated fluid responsiveness based on stroke volume variation (SVV) or passive leg raising test were administered a FB of 500 ml plasma-lyte A (Baxter Healthcare) and underwent pre- and post-FB assessments of stroke volume, CO, MAP, CVP, haemoglobin, PaO₂ and SctO₂.

Results

52 patients (mean age 64 ± 12 years, 75% male) received a total of 115 FB. Although administration of a FB resulted in a significant increase of stroke volume (63 ± 22 vs 67 ± 23 mL, p = 0.001), CO (4,2 ± 1,6 vs 4,4 ± 1,7 L/min, p = 0.001) and MAP (74,8 ± 13,2 vs 79,2 ± 12,9 mmHg, p = 0.004), it did not improve SctO₂ (68.54 ± 6.99 vs 68.70 ± 6.80%, p = 0.49). Fluid bolus administration also resulted in a significant increase of CVP (10,0 ± 4,5 vs 10,7 ± 4,9 mmHg, p = 0.02), but did not affect PaO₂ (99 ± 31 vs 94 ± 31 mmHg, p = 0.15) or haemoglobin concentrations (12,9 ± 2,1 vs 12,8 ± 2,2 g/dL, p = 0.10). In a multivariate model, FB-induced changes in CO (beta 0,77; p = 0.004) and in CVP (beta −0,23; p = 0.02) but not in MAP (beta 0,02; p = 0.18) predicted post-FB ΔSctO₂.

Conclusions

Despite improvements in CO and MAP, FB administration did not improve SctO₂ in post-cardiac arrest patients.

中文翻译：

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补液对心脏骤停后患者脑组织氧合的影响

目的

液体推注 (FB) 常用于血流动力学不稳定的心脏骤停 (CA) 后患者。尽管 FB 可以改善心输出量 (CO) 和平均动脉压 (MAP)，但 FB 也可能增加中心静脉压 (CVP)，降低动脉 PaO ₂，稀释血红蛋白并引起间质水肿。本研究的目的是研究 FB 给药对CA 后患者脑组织氧合饱和度 (SctO ₂ )的净影响。

方法

Neuroprotect 后 CA 试验的预先计划的子研究 (NCT02541591)。根据每搏量变异 (SVV) 或被动抬腿试验具有预期液体反应性的患者接受 500 ml 血浆 A (Baxter Healthcare) 的 FB，并在 FB 前和后评估每搏量、CO、MAP、 CVP、血红蛋白、PaO ₂和 SctO ₂。

结果

52 名患者（平均年龄 64 ± 12 岁，75% 为男性）总共接受了 115 FB。尽管给予 FB 导致每搏输出量显着增加（63 ± 22 对 67 ± 23 mL，p  = 0.001），CO（4,2 ± 1,6 对 4,4 ± 1,7 L/min，p  = 0.001) 和 MAP（74,8 ± 13,2 对 79,2 ± 12,9 mmHg，p  = 0.004），它没有改善 SctO ₂（68.54 ± 6.99 对 68.70 ± 6.80%，p  = 0.49）。液体推注给药也导致 CVP 显着增加（10,0 ± 4,5 对 10,7 ± 4,9 mmHg，p  = 0.02），但不影响 PaO ₂（99 ± 31 对 94 ± 31 mmHg，p  = 0.15) 或血红蛋白浓度 (12,9 ± 2,1 vs 12,8 ± 2,2 g/dL, p = 0.10）。在多变量模型中，FB 诱导的 CO（β 0,77；p  = 0.004）和 CVP（β -0,23；p  = 0.02）变化但不是 MAP（β 0,02；p  = 0.18）预测FB 后 ΔScO ₂。

结论

尽管 CO 和 MAP 有所改善，但 FB 给药并未改善心脏骤停后患者的SctO ₂。