Cumulative Fluid Balance and Mortality in Septic Patients With or Without Acute Kidney Injury and Chronic Kidney Disease. (Chaudhary)

Neyra JA, Li X, et al. Cumulative Fluid Balance and Mortality in Septic Patients With or Without Acute Kidney Injury and Chronic Kidney Disease. Crit Care Med. 2016 Oct;44(10):1891-900.

OBJECTIVE: Incident acute kidney injury and prevalent chronic kidney disease are commonly encountered in septic patients. We examined the differential effect of acute kidney injury and chronic kidney disease on the association between cumulative fluid balance and hospital mortality in critically ill septic patients.

DESIGN: Retrospective cohort study.

SETTING: Urban academic medical center ICU.

PATIENTS: ICU adult patients with severe sepsis or septic shock and seruacutem creatinine measured within 3 months prior to and 72 hours of ICU admission. Patients with estimated glomerular filtration rate less than 15 mL/min/1.73 m or receiving chronic dialysis were excluded.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: A total of 2,632 patients, 1,211 with chronic kidney disease, were followed up until hospital death or discharge. Acute kidney injury occurred in 1,525 patients (57.9%), of whom 679 (44.5%) had chronic kidney disease. Hospital mortality occurred in 603 patients (22.9%). Every 1-L increase in cumulative fluid balance at 72 hours of ICU admission was independently associated with hospital mortality in all patients (adjusted odds ratio, 1.06 [95% CI] 1.04-1.08; p < 0.001), and in each acute kidney injury/chronic kidney disease subgroup (adjusted odds ratio, 1.06 [1.03-1.09] for acute kidney injury+/chronic kidney disease+; 1.09 [1.05-1.13] for acute kidney injury-/chronic kidney disease+; 1.05 [1.03-1.08] for acute kidney injury+/chronic kidney disease-; and 1.07 [1.02-1.11] for acute kidney injury-/chronic kidney disease-). There was a significant interaction between acute kidney injury and chronic kidney disease on cumulative fluid balance (p =0.005) such that different cumulative fluid balance cut-offs with the best prognostic accuracy for hospital mortality were identified: 5.9 L for acute kidney injury+/chronic kidney disease+; 3.8 L for acute kidney injury-/chronic kidney disease+; 4.3 L for acute kidney injury+/chronic kidney disease-; and 1.5 L for acute kidney injury-/chronic kidney disease-. The addition of cumulative fluid balance to the admission Sequential Organ Failure Assessment score had increased prognostic utility for hospital mortality when compared with Sequential Organ Failure Assessment alone, particularly in patients with acute kidney injury.

CONCLUSIONS: Higher cumulative fluid balance at 72 hours of ICU admission was independently associated with hospital mortality regardless of acute kidney injury or chronic kidney disease presence. We characterized cumulative fluid balance cut-offs associated with hospital mortality based on acute kidney injury/chronic kidney disease status, underpinning the heterogeneity of fluid regulation in sepsis and kidney disease.

Lactated Ringer Is Associated With Reduced Mortality and Less Acute Kidney Injury in Critically Ill Patients: A Retrospective Cohort Analysis. (Colman)

Zampieri FG, et al. Lactated Ringer Is Associated With Reduced Mortality and Less Acute Kidney Injury in Critically Ill Patients: A Retrospective Cohort Analysis. Crit Care Med. 2016 Aug 5. [Epub ahead of print]

OBJECTIVES: To assess the impact of the percentage of fluid infused as Lactated Ringer (%LR) during the first 2 days of ICU admission in hospital mortality and occurrence of acute kidney injury.

DESIGN: Retrospective cohort.

SETTING: Analysis of a large public database (Multiparameter Intelligent Monitoring in Intensive Care-II).

PATIENTS: Adult patients with at least 2 days of ICU stay, admission creatinine lower than 5 mg/dL, and that received at least 500 mL of fluid in the first 48 hours.

INTERVENTIONS: None.

MEASUREMENT AND MAIN RESULTS: 10,249 patients were included in mortality analysis and 8,085 were included in the acute kidney injury analysis. For acute kidney injury analysis, we excluded patients achieving acute kidney injury criteria in the first 2 days of ICU stay. Acute kidney injury was defined as stage 2/3 Kidney Disease: Improving Global Outcomes creatinine criteria and was assessed from days 3-7. The effects of %LR in both outcomes were assessed through logistic regression controlling for confounders. Principal component analysis was applied to assess the effect of volume of each fluid type on mortality. Higher %LR was associated with lower mortality and less acute kidney injury. %LR effect increased with total volume of fluid infused. For patients in the fourth quartile of fluid volume (> 7 L), the odds ratio for mortality for %LR equal to 75% versus %LR equal to 25% was 0.50 (95% CI, 0.32-0.79; p < 0.001). Principal component analysis suggested that volume of Lactated Ringer and 0.9% saline infused had opposite effects in outcome, favoring Lactated Ringer.

CONCLUSIONS: Higher %LR was associated with reduced hospital mortality and with less acute kidney injury from days 3-7 after ICU admission. The association between %LR and mortality was influenced by the total volume of fluids infused.

Dexmedetomidine Is Associated With Lower Incidence of Acute Kidney Injury After Congenital Heart Surgery. (Patel)

Kwiatkowski DM, et al. Dexmedetomidine Is Associated With Lower Incidence of Acute Kidney Injury After Congenital Heart Surgery. Pediatr Crit Care Med. 2016 Feb;17(2):128-34.

OBJECTIVES: Recent data have suggested an association between the use of dexmedetomidine and a decreased incidence of acute kidney injury in adult patients after cardiopulmonary bypass. However, no study has focused on this association among pediatric populations where the incidence of acute kidney injury is particularly high and of critical significance. The primary objective of this study was to assess the relationship between the use of postoperative dexmedetomidine and the incidence of acute kidney injury in pediatric patients undergoing cardiopulmonary bypass. The secondary objective was to determine whether there was an association between dexmedetomidine use and duration of mechanical ventilation or cardiovascular ICU stay.

DESIGN: Single-center retrospective matched cohort study.

SETTING: A 20-bed quaternary cardiovascular ICU in a university-based pediatric hospital in California.

PATIENTS: Children less than 18 years old admitted after cardiac surgery with cardiopulmonary bypass between January 1, 2012, and May 31, 2014.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Data from a cohort of 102 patients receiving dexmedetomidine during the first postoperative day after cardiac surgery were compared to an age- and procedure-matched cohort not receiving dexmedetomidine. Cohorts had similar baseline and demographic characteristics. Patients receiving dexmedetomidine were less likely to develop acute kidney injury (24% vs 36%; odds ratio, 0.54; 95% CI, 0.29-0.99; p = 0.046). After adjusting for age, bypass time, nephrotoxin use, and vasoactive inotropic score, the use of dexmedetomidine was associated with a lower incidence of acute kidney injury with adjusted odds ratio of 0.43 (95% CI, 0.27-0.98; p = 0.048). There was no difference between the cohorts with respect to the duration of mechanical duration (1 d each; p = 0.98) or cardiovascular ICU stays (5 vs 6 d; p = 0.91).

CONCLUSIONS: The use of a dexmedetomidine infusion in pediatric patients after congenital heart surgery was associated with a decreased incidence of acute kidney injury; however, it was not associated with changes in clinical outcomes. Further prospective study is necessary to validate these findings.

Obesity, Acute Kidney Injury, and Mortality in Critical Illness. (Emrath)

Danziger J, et al. Obesity, Acute Kidney Injury, and Mortality in Critical Illness. Crit Care Med. 2016 Feb;44(2):328-34.

OBJECTIVES: Although obesity is associated with risk for chronic kidney disease and improved survival, less is known about the associations of obesity with risk of acute kidney injury and post acute kidney injury mortality.

DESIGN: In a single-center inception cohort of almost 15,000 critically ill patients, we evaluated the association of obesity with acute kidney injury and acute kidney injury severity, as well as in-hospital and 1-year survival. Acute kidney injury was defined using the Kidney Disease Outcome Quality Initiative criteria.

MEASUREMENTS AND MAIN RESULTS: The acute kidney injury prevalence rates for normal, overweight, class I, II, and III obesity were 18.6%, 20.6%, 22.5%, 24.3%, and 24.0%, respectively, and the adjusted odds ratios of acute kidney injury were 1.18 (95% CI, 1.06-1.31), 1.35 (1.19-1.53), 1.47 (1.25-1.73), and 1.59 (1.31-1.87) when compared with normal weight, respectively. Each 5-kg/m increase in body mass index was associated with a 10% risk (95% CI, 1.06-1.24; p < 0.001) of more severe acute kidney injury. Within-hospital and 1-year survival rates associated with the acute kidney injury episodes were similar across body mass index categories.

CONCLUSION: Obesity is a risk factor for acute kidney injury, which is associated with increased short- and long-term mortality.