Urine volume as a predicting factor for furosemide clearance during continuous infusion in AKI septic shock patients on hemodiafiltration

The furosemide stress test predicts the timing of continuous renal replacement therapy initiation in critically ill patients with acute kidney injury: a double-blind prospective intervention cohort study

BACKGROUND

Continuous renal replacement therapy (CRRT) remains a crucial treatment for critically ill patients with acute kidney injury (AKI), although the timing of its initiation is still a matter of contention. Furosemide stress testing (FST) may be a practical and beneficial prediction instrument. This research was meant to examine if FST can be used to identify high-risk patients for CRRT.

METHODS

This study is a double-blind, prospective interventional cohort study. For patients with AKI receiving intensive care unit (ICU) income, FST was selected with furosemide 1 mg/kg intravenous (1.5 mg/kg intravenous if a loop diuretic was received within 7 days). Urinary volume more than 200 ml at 2 h after FST was FST-responsive, less than 200 ml was FST-nonresponsive. The FST results are kept strictly confidential from the clinician, who decides whether to initiate CRRT based on laboratory testing and clinical symptoms other than the FST data. The FST data are concealed from both the patients and the clinician.

RESULTS

FST was delivered to 187 of 241 patients who satisfied the inclusion and exclusion criteria, with 48 patients responding to the test and 139 patients not responding. 18/48 (37.5%) of the FST-responsive patients received CRRT, while 124/139 (89.2%) of the FST-nonresponsive patients received CRRT. There was no significant difference between the CRRT and non-CRRT groups in terms of general health and medical history (P > 0.05). Urine volume after 2 h of FST was considerably lower in the CRRT group than in the non-CRRT group (35 ml, IQR5-143.75 versus 400 ml, IQR210-890; P = 0.000). FST non-responders were 2.379 times more likely to initiate CRRT than FST responders (95% CI 1.644-3.443, P = 0.000). The area under the curve (AUC) for initiating CRRT was 0.966 (cutoff of 156 ml, sensitivity of 94.85%, specificity of 98.04%, P < 0.001).

CONCLUSION

This study demonstrated that FST is a safe and practical approach for predicting the initiation of CRRT in critically ill AKI patients. Trial registration www.chictr.org.cn , ChiCTR1800015734, Registered 17 April 2018.

Diuretic strategies in patients with resistance to loop-diuretics in the intensive care unit: A retrospective study from the MIMIC-III database

PURPOSE

To investigate various diuretic strategies to alleviate loop-diuretics resistance in critically ill patients.

MATERIALS AND METHOD

ICU adults requiring more than 1 mg/kg/day of furosemide, from the MIMIC-III database. Four diuretic strategies were investigated: incremental dose of loop diuretics, continuous infusion, combinations with a second class of diuretics and administration of intravenous albumin. A generalized estimating equation was used to investigate the associations between these strategies and endpoints. The primary outcome was the 24-h urine output and secondary endpoints included fluid balance, weight change, electrolyte and acid-base abnormalities, kidney replacement therapy initiation, and mortality.

RESULTS

A total of 7645 ICU stays from 6358 patients were included. After adjustment, the use of continuous loop-diuretic infusion was associated with a higher 24-h urine output (β: 732, 95% CI:669-795, p < 0.001), lower 24-h fluid balance (p < 0.001) and greater weight loss at 48-h (p < 0.001). Thiazide- and carbonic anhydrase inhibitor combinations were both associated with higher urine output (p < 0.001) and weight loss at 48-h (p < 0.01), while intravenous albumin was associated with fluid gain (p < 0.001). Risks of electrolyte and metabolic disturbances varied across diuretic strategies.

CONCLUSIONS

Continuous loop-diuretic infusion and thiazide- or acetazolamide-loop diuretic combinations increased urine output significantly, leading to a negative fluid balance and weight loss.

Furosemide as a functional marker of acute kidney injury in ICU patients: a new role for an old drug

New pharmacokinetics insight suggests that the furosemide pharmacology occurring in ICU patients with AKI is similar, but not equal to that described in chronic stable renal patients. Even if the diuretic response to furosemide is expressed by a steep dose-response curve positively correlated with renal function, pharmacodynamic limitations occur when creatinine clearance is < 20 ml/min or urine output is < 500 ml/12 h. In such cases, other factors specifically due to acute tubular injury can interfere with the furosemide-induced diuretic output. As modality of administration recent reports and metanalysis, even if not conclusive, suggest that for the same given dose a continuous infusion of furosemide was superior in diuretic response. For septic shock patients on CVVHDF where treatment adds an additional clearance of furosemide the maximum diuretic response is achieved by a continuous infusion of 20 mg/h of furosemide. At this infusion rate the reached plasma level was < 20 mg/L, a range considered safe and not ototoxic. Therefore, the severity of AKI establishes whether a patient will respond to furosemide. In this review we summarized all these recent updates, also suggesting that the diuretic response under continuous infusion may allow assessing glomerular and tubular functions with increased reliability than a bolus dose. However, validation studies are still needed to support continuous infusion as a stress test.