Hypophosphatemia during continuous veno-venous hemofiltration is associated with mortality in critically ill patients with acute kidney injury

Abstract

IntroductionThe primary aim of this study was to determine whether hypophosphatemia during continuous veno-venous hemofiltration (CVVH) is associated with the global outcome of critically ill patients with acute kidney injury (AKI).Methods760 patients diagnosed with AKI and had received CVVH therapy were retrospectively recruited. Death during the 28-day period and survival at 28 days after initiation of CVVH were used as endpoints. Demographic and clinical data including serum phosphorus levels were recorded along with clinical outcome. Hypophosphatemia was defined according to the colorimetric method as serum phosphorus levels < 0.81 mmol/L (2.5 mg/dL), and severe hypophosphatemia was defined as serum phosphorus levels < 0.32 mmol/L (1 mg/dL). The ratio of CVVH therapy days with hypophosphatemia over total CVVH therapy days was calculated to reflect the persistence of hypophosphatemia.ResultsThe Cox proportional hazard survival model analysis indicated that the incidence of hypophosphatemia or even severe hypophosphatemia was not associated with 28-day mortality independently (p = 0.700). Further analysis with the sub-cohort of patients who had developed hypophosphatemia during the CVVH therapy period indicated that the mean ratio of CVVH therapy days with hypophosphatemia over total CVVH therapy days was 0.58, and the ratio independently associated with the global outcome. Compared with the patients with low ratio (< 0.58), those with high ratio (≥ 0.58) conferred a 1.451-fold increase in 28-day mortality rate (95% CI 1.103–1.910, p = 0.008).ConclusionsHypophosphatemia during CVVH associated with the global clinical outcome of critically ill patients with AKI. The ratio of CVVH therapy days with hypophosphatemia over total CVVH therapy days was independently associated with the 28-day mortality, and high ratio conferred higher mortality rate.

Preventing Continuous Renal Replacement Therapy-Induced Hypophosphatemia: An Extended Clinical Experience with a Phosphate-Containing Solution in the Setting of Regional Citrate Anticoagulation

“…It should be underscored that protocol-guided supplementation was sporadically needed, and mainly required in patients already hypophosphatemic at the start of CRRT. Stressing the importance of strategies aimed at preventing, rather than curing, hypophosphatemia, Yang et al [9] recently reported that the ratio of CVVH therapy days with hypophosphatemia to total CVVH days was independently associated with global outcome. The authors highlighted that parenteral phosphate supplementation failed to prevent CVVH-related hypophosphatemia in a majority of the patients underlining that the use of CRRT phosphate-containing solutions could represent a more appropriate option.…”

“…Hypophosphatemia is a frequent finding among critically ill patients and its incidence can be further increased by the use of prolonged and intensive modalities of RRT [3][4][5][6][7][8][9] , which achieve a very efficient phosphate clearance [2,13] . Indeed, in 2 large clinical trials, patients receiving the most intensive RRT modalities experienced a higher incidence of hypophosphatemia [4,5] .…”

“…Hypophosphatemia is common among intensive care unit (ICU) patients [1,2] with an incidence of up to 80% in patients undergoing continuous renal replacement therapy (CRRT) with standard dialysis/replacement solutions [3][4][5][6][7][8][9] , especially when highly efficient modalities are employed [4,5] . Hypophosphatemia may negatively impact on respiratory, central nervous and cardiovascular systems.…”

Continuous Renal Replacement Therapy for Acute Kidney Injury Using Phosphate Containing Fluid is Associated With Greater Biochemical Derangement than Conventional Fluid

“…In our study 9 2-] pl were initiated on RRT with Phoxilium, reflecting the common observation that establishing a 'default' clinical pathway can inadvertently impede the application of clinical judgement. These data reinforce the view that a patient centred RRT strategy is preferable to a 'one size fits all' approach.…”

“…8 Hypophosphataemia is independently associated with worse ICU survival; the duration of hypophosphataemia predicts mortality. 9 Phoxilium is a phosphate and potassium containing CRRT fluid, introduced to mitigate the risk of hypophosphataemia and need for potassium supplementation. 10 The composition of Hemosol-B0 and Phoxilium are compared in Table 1 10 It is common practice in most intensive care units to identify a default fluid to be used for CRRT.…”