Renal replacement therapy with net fluid removal lowers intra-abdominal pressure and volumetric indices in critically ill patients

Abstract

BackgroundLittle is known about the effects of renal replacement therapy (RRT) with fluid removal on intra-abdominal pressure (IAP). The global end-diastolic volume index (GEDVI) and extravascular lung water index (EVLWI) can easily be measured bedside by transpulmonary thermodilution (TPTD). The aim of this study is to evaluate the changes in IAP, GEDVI and EVLWI in critically ill patients receiving slow extended daily dialysis (SLEDD) or continuous venovenous haemofiltration (CVVH) with the intention of net fluid removal.MethodsWe performed a retrospective cohort study in ICU patients who were treated with SLEDD or CVVH and in whom IAP was also measured, and RRT sessions were excluded when the dose of vasoactive medication needed to be changed between the pre- and post-dialysis TPTD measurements and when net fluid loss did not exceed 500 ml. The TPTD measurements were performed within 2 h before and after SLEDD; in case of CVVH, before and after an interval of 12 h.ResultsWe studied 25 consecutive dialysis sessions in nine patients with acute renal failure and cardiogenic or non-cardiogenic pulmonary oedema. The GEDVI and EVLWI values before dialysis were 877 ml/m² and 14 ml/kg, respectively. Average net ultrafiltration per session was 3.6 l, with a net fluid loss 1.9 l. The GEDVI decreased significantly during dialysis, but not more than 47.8 ml/m² (p = 0.008), as also did the EVLWI with 1 ml/kg (p = 0.03). The IAP decreased significantly from 12 to 10.5 mmHg (p < 0.0001).ConclusionsNet fluid removal by SLEDD or CVVH in the range observed in this study decreased IAP, GEDVI and EVLWI in critically ill patients although EVLWI reduction was modest.

Changes in Volumetric Hemodynamic Parameters Induced by Fluid Removal on Hemodialysis in Critically Ill Patients

“…On the one hand, our findings confirm results from our previous study and are also in accordance with a recently published retrospective cohort analysis : EVLWI was found to be elevated before hemodialysis, indicating excess pulmonary fluid, and a significant reduction was observed with fluid removal on dialysis. In contrast, the preload parameter ITBVI remained unchanged.…”

“…According to another study, extracorporal circulation during RRT per se did not lead to biased volumetric hemodynamic measurements . In a small pilot study published in 2007, we reported significant decreases in EVLW with fluid removal on intermittent hemodialysis in critically ill patients—a finding that was recently confirmed in a study by De Laet and co‐workers with an equivalently small sample size of nine patients . The present study was conducted to reassess and report potential changes in volumetric hemodynamic measurements with fluid removal on hemodialysis in a larger group of 35 ICU patients with ARF.…”

Management of peripartum intra‐abdominal hypertension and abdominal compartment syndrome

“…Renal replacement therapy with ultrafiltration has also been shown to decrease IAP . The indications for diuresis and renal replacement therapy are not established, but this may reduce cumulative fluid balance and IAP.…”

“…43 Renal replacement therapy with ultrafiltration has also been shown to decrease IAP. 44 The indications for diuresis and renal replacement therapy are not established, but this may reduce cumulative fluid balance and IAP. These strategies should be performed cautiously once the patient has been stabilized from the initial insult to avoid precipitating intravascular hypovolemia and hemodynamic instability.…”

Fluid therapy and perfusional considerations during resuscitation in critically ill patients with intra-abdominal hypertension

“…De laet et al demonstrated similarly that RRT with a mean net fluid loss of 1.9 L in a total of 25 dialysis sessions decreased IAP from 12 to 11 mm Hg (P < 0.0001) [35]. Finally, Dabrowski et al recently concluded that continuous RRT to reduce fluid overload in patients with septic shock and acute kidney injury reduces IAP [36].…”