[Evaluation of high volume hemofiltration according to pulse-indicated continuous cardiac output on patients with acute respiratory distress syndrome]

Abstract

Objective: To study the effects of high volume hemofiltration (HVHF) according to pulse-indicated continuous cardiac output (PiCCO) on patients with acute respiratory distress syndrome (ARDS).

Methods: A prospective randomly controlled trial was conducted. 163 patients with ARDS admitted to Taizhou People's Hospital, Medical College, Nantong University, between February 2011 and January 2014, were enrolled. The patients were randomly divided into conventional therapy group (n=50), HVHF group (n=55), and PiCCO + HVHF group (n=58) by random number table. The patients in conventional therapy group received routine treatment including mechanical ventilation and drug treatment according to ARDS treatment guideline. The patients in the HVHF group received HVHF treatment of 18 hours per day on 1, 3, 5, 7 days on the basis of conventional therapy. Patients in the PiCCO + HVHF group received HVHF treatment according to PiCCO. The indexes of lung function and PiCCO monitoring were recorded at intensive care unit (ICU) admission (before) and 4 days and 7 days after treatment. The serum levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were determined by enzyme linked immunosorbent assay (ELISA), and the prognosis of patients was recorded.

Results: In three groups, oxygenation index (PaO₂/FiO₂), static lung compliance (Cs) were gradually increased, and respiratory rate (RR), lactic acid (Lac) were gradually decreased. The indicators in HVHF and PiCCO + HVHF groups were significantly improved compared with conventional therapy group. The indexes in PiCCO + HVHF group were significantly increased or decreased compared with those in HVHF group, and the statistical differences were found on the 7th day after treatment [PaO₂/FiO₂(mmHg, 1 mmHg=0.133 kPa): 189.3 ± 36.8 vs. 166.3 ± 36.1, Cs (mL/cmH₂O): 76.7 ± 18.9 vs. 67.0 ± 18.2, RR (times/min): 16.4 ± 5.2 vs. 19.2 ± 5.4, Lac (mmol/L): 1.20 ± 0.41 vs. 1.41 ± 0.43, all P<0.01]. In PiCCO + HVHF group, cardiac index (CI) was gradually increased, and extra vascular lung water index (EVLWI) and intra thoracic blood volume index (ITBVI) were gradually decreased. There were significant differences in the indexes 4 days and 7 days after treatment compared with those before treatment [CI (L × min⁻¹ m⁻²): 4.62 ± 1.13, 4.83 ± 1.10 vs. 4.01 ± 1.02, EVLWI (mL/kg): 7.6 ± 2.7, 6.5 ± 2.6 vs. 12.4 ± 2.9, ITBVI (mL/m²): 801.3 ± 120.9, 785.4 ± 118.7 vs. 980.1 ± 168.6, all P<0.01]. After treatment, the serum levels of TNF-α and IL-1β in three groups were gradually decreased. Compared with the conventional therapy group, the serum levels of TNF-α and IL-1β on 4 days and 7 days in the HVHF and PiCCO + HVHF groups were significantly decreased, and the statistical differences were found on 7 days [TNF-α (ng/L): 68.35 ± 12.63, 67.54 ± 12.90 vs. 85.35 ± 13.70; IL-1β (ng/L): 424.6 ± 142.9, 412.2 ± 140.2 vs. 895.2 ± 187.7, all P<0.01]. Compared with the HVHF group, the serum levels of TNF-α and IL-1β in the PiCCO + HVHF group were slightly decreased without statistical differences. Compared with the conventional therapy group, the number of organ failure, duration of mechanical ventilation, the length of stay in ICU and hospital mortality in HVHF group and PiCCO + HVHF group were lowered, and the statistical differences were found in PiCCO + HVHF group compared with HVHF group [number of organ failure: 2.41 ± 0.79 vs. 2.72 ± 0.80, duration of mechanical ventilation (days): 4.8 ± 2.0 vs. 5.7 ± 2.1, the length of stay in ICU (days): 11.5 ± 3.4 vs. 13.1 ± 3.6, hospital mortality: 31.0% (18/58) vs. 41.8% (23/55), all P<0.05].

Conclusions: Levels of inflammatory factors in patients with ARDS could be reduced by HVHF. The oxygenation and compliance of lung can be improved, the number of organ failure can be lowered, the duration of mechanical ventilation and the length of stay in ICU can be shortened, and the hospital mortality could be declined by PiCCO guided HVHF.