Anna-Maija Korhonen

Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study

PurposeCurrent reports on acute kidney injury (AKI) in the intensive care unit (ICU) show wide variation in occurrence rate and are limited by study biases such as use of incomplete AKI definition, selected cohorts, or retrospective design. Our aim was to prospectively investigate the occurrence and outcomes of AKI in ICU patients.MethodsThe Acute Kidney Injury–Epidemiologic Prospective Investigation (AKI-EPI) study was an international cross-sectional study performed in 97 centers on patients during the first week of ICU admission. We measured AKI by Kidney Disease: Improving Global Outcomes (KDIGO) criteria, and outcomes at hospital discharge.ResultsA total of 1032 ICU patients out of 1802 [57.3xa0%; 95xa0% confidence interval (CI) 55.0–59.6] had AKI. Increasing AKI severity was associated with hospital mortality when adjusted for other variables; odds ratio of stagexa01xa0=xa01.679 (95xa0% CI 0.890–3.169; pxa0=xa00.109), stagexa02xa0=xa02.945 (95xa0% CI 1.382–6.276; pxa0=xa00.005), and stagexa03xa0=xa06.884 (95xa0% CI 3.876–12.228; pxa0<xa00.001). Risk-adjusted rates of AKI and mortality were similar across the world. Patients developing AKI had worse kidney function at hospital discharge with estimated glomerular filtration ratexa0less thanxa060xa0mL/min/1.73xa0m2 in 47.7xa0% (95xa0% CI 43.6–51.7) versus 14.8xa0% (95xa0% CI 11.9–18.2) in those without AKI, pxa0<xa00.001.ConclusionsThis is the first multinational cross-sectional study on the epidemiology of AKI in ICU patients using the complete KDIGO criteria. We found that AKI occurred in more than half of ICU patients. Increasing AKI severity was associated with increased mortality, and AKI patients had worse renal function at the time of hospital discharge. Adjusted risks for AKI and mortality were similar across different continents and regions.

Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study

PurposeWe aimed to determine the incidence, risk factors and outcome of acute kidney injury (AKI) in Finnish ICUs.MethodsThis prospective, observational, multi-centre study comprised adult emergency admissions and elective patients whose stay exceeded 24xa0h during a 5-month period in 17 Finnish ICUs. We defined AKI first by the Acute Kidney Injury Network (AKIN) criteria supplemented with a baseline creatinine and second with the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. We screened the patients’ AKI status and risk factors for up to 5xa0days.ResultsWe included 2,901 patients. The incidence (95xa0% confidence interval) of AKI was 39.3xa0% (37.5–41.1xa0%). The incidence was 17.2xa0% (15.8–18.6xa0%) for stage 1, 8.0xa0% (7.0–9.0xa0%) for stage 2 and 14.1xa0% (12.8–15.4xa0%) for stage 3 AKI. Of the 2,901 patients 296 [10.2xa0% (9.1–11.3xa0%)] received renal replacement therapy. We received an identical classification with the new KDIGO criteria. The population-based incidence (95xa0% CI) of ICU-treated AKI was 746 (717–774) per million population per year (reference population: 3,671,143, i.e. 85xa0% of the Finnish adult population). In logistic regression, pre-ICU hypovolaemia, diuretics, colloids and chronic kidney disease were independent risk factors for AKI. Hospital mortality (95xa0% CI) for AKI patients was 25.6xa0% (23.0–28.2xa0%) and the 90-day mortality for AKI patients was 33.7xa0% (30.9–36.5xa0%). All AKIN stages were independently associated with 90-day mortality.ConclusionsThe incidence of AKI in the critically ill in Finland was comparable to previous large multi-centre ICU studies. Hospital mortality (26xa0%) in AKI patients appeared comparable to or lower than in other studies.

Fluid overload is associated with an increased risk for 90-day mortality in critically ill patients with renal replacement therapy: data from the prospective FINNAKI study

IntroductionPositive fluid balance has been associated with an increased risk for mortality in critically ill patients with acute kidney injury with or without renal replacement therapy (RRT). Data on fluid accumulation prior to RRT initiation and mortality are limited. We aimed to study the association between fluid accumulation at RRT initiation and 90-day mortality.MethodsWe conducted a prospective, multicenter, observational cohort study in 17 Finnish intensive care units (ICUs) during a five-month period. We collected data on patient characteristics, RRT timing, and parameters at RRT initiation. We studied the association of parameters at RRT initiation, including fluid overload (defined as cumulative fluid accumulation > 10% of baseline weight) with 90-day mortality.ResultsWe included 296 RRT-treated critically ill patients. Of 283 patients with complete data on fluid balance, 76 (26.9%) patients had fluid overload. The median (interquartile range) time from ICU admission to RRT initiation was 14 (3.3 to 41.5) hours. The 90-day mortality rate of the whole cohort was 116 of 296 (39.2%; 95% confidence interval 38.6 to 39.8%). The crude 90-day mortality of patients with or without fluid overload was 45 of 76 (59.2%) vs. 65 of 207 (31.4%), P < 0.001. In logistic regression, fluid overload was associated with an increased risk for 90-day mortality (odds ratio 2.6) after adjusting for disease severity, time of RRT initiation, initial RRT modality, and sepsis. Of the 168 survivors with data on RRT use at 90 days, 34 (18.9%, 95% CI 13.2 to 24.6%) were still dependent on RRT.ConclusionsPatients with fluid overload at RRT initiation had twice as high crude 90-day mortality compared to those without. Fluid overload was associated with increased risk for 90-day mortality even after adjustments.

Intrathecal hyperbaric bupivacaine 3 mg + fentanyl 10 µg for outpatient knee arthroscopy with tourniquet

Background:u2003 Combination of local anesthetic and opioid enables the use of less spinal anesthetic and increases the success of anesthesia. Intrathecal opioid does not prolong motor recovery and thus should not delay discharge home. We hypothesized that 3u2003mg of hyperbaric bupivacaine with 10u2003µg of fentanyl permits fast‐tracking or shorter stay in post anesthesia care unit (PACU), and earlier discharge home, compared with 4u2003mg of hyperbaric bupivacaine.

Hemodynamic variables and progression of acute kidney injury in critically ill patients with severe sepsis: data from the prospective observational FINNAKI study

IntroductionKnowledge of the association of hemodynamics with progression of septic acute kidney injury (AKI) is limited. However, some recent data suggest that mean arterial pressure (MAP) exceeding current guidelines (60–65 mmHg) may be needed to prevent AKI. We hypothesized that higher MAP during the first 24 hours in the intensive care unit (ICU), would be associated with a lower risk of progression of AKI in patients with severe sepsis.MethodsWe identified 423 patients with severe sepsis and electronically recorded continuous hemodynamic data in the prospective observational FINNAKI study. The primary endpoint was progression of AKI within the first 5 days of ICU admission defined as new onset or worsening of AKI by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. We evaluated the association of hemodynamic variables with this endpoint. We included 53724 10-minute medians of MAP in the analysis. We analysed the ability of time-adjusted MAP to predict progression of AKI by receiver operating characteristic (ROC) analysis.ResultsOf 423 patients, 153 (36.2%) had progression of AKI. Patients with progression of AKI had significantly lower time-adjusted MAP, 74.4 mmHg [68.3-80.8], than those without progression, 78.6 mmHg [72.9-85.4], Pu2009<u20090.001. A cut-off value of 73 mmHg for time-adjusted MAP best predicted the progression of AKI. Chronic kidney disease, higher lactate, higher dose of furosemide, use of dobutamine and time-adjusted MAP below 73 mmHg were independent predictors of progression of AKI.ConclusionsThe findings of this large prospective multicenter observational study suggest that hypotensive episodes (MAP under 73 mmHg) are associated with progression of AKI in critically ill patients with severe sepsis.

Ondansetron does not prevent pruritus induced by low-dose intrathecal fentanyl

Background:u2002 Addition of an opioid to low‐dose spinal anesthesia with bupivacaine improves the quality and success of anesthesia. However, the intrathecal fentanyl‐induced pruritus is as high as 75%. We hypothesized that after administration of 4 or 8u2003mg of prophylactic IV ondansetron, the incidence of pruritus induced by low‐dose intrathecal fentanyl would be significantly lower than after placebo.

Six-month survival and quality of life of intensive care patients with acute kidney injury.

IntroductionAcute kidney injury (AKI) has high incidence among the critically ill and associates with dismal outcome. Not only the long-term survival, but also the quality of life (QOL) of patients with AKI is relevant due to substantial burden of care regarding these patients. We aimed to study the long-term outcome and QOL of patients with AKI treated in intensive care units.MethodsWe conducted a predefined six-month follow-up of adult intensive care unit (ICU) patients from the prospective, observational, multi-centre FINNAKI study. We evaluated the QOL of survivors with the EuroQol (EQ-5D) questionnaire. We included all participating sites with at least 70% rate of QOL measurements in the analysis.ResultsOf the 1,568 study patients, 635 (40.5%, 95% confidence interval (CI) 38.0-43.0%) had AKI according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Of the 635 AKI patients, 224 (35.3%), as compared to 154/933 (16.5%) patients without AKI, died within six months. Of the 1,190 survivors, 959 (80.6%) answered the EQ-5D questionnaire at six months. The QOL (median with Interquartile range, IQR) measured with the EQ-5D index and compared to age- and sex-matched general population was: 0.676 (0.520-1.00) versus 0.826 (0.812-0.859) for AKI patients, and 0.690 (0.533-1.00) versus 0.845 (0.812-0.882) for patients without AKI (Pu2009<0.001 in both). The EQ-5D at the time of ICU admission was available for 774 (80.7%) of the six-month respondents. We detected a mean increase of 0.017 for non-AKI and of 0.024 for AKI patients in the EQ-5D index (Pu2009=u20090.728). The EQ-5D visual analogue scores (median with IQR) of patients with AKI (70 (50–83)) and patients without AKI (75 (60–87)) were not different from the age- and sex-matched general population (69 (68–73) and 70 (68–77)).ConclusionsThe health-related quality of life of patients with and without AKI was already lower on ICU admission than that of the age- and sex-matched general population, and did not change significantly during critical illness. Patients with and without AKI rate their subjective health to be as good as age and sex-matched general population despite statistically significantly lower QOL indexes measured by EQ-5D.

The attributable mortality of acute kidney injury: a sequentially matched analysis*.

Objective:Acute kidney injury in the critically ill is an independent risk factor for adverse outcome. The magnitude of the impact of acute kidney injury on outcome, however, is still unclear. This study aimed to estimate the excess mortality attributable to acute kidney injury. Design:We performed a sequentially matched analysis according to the day of acute kidney injury diagnosis after ICU admission. Patients with acute kidney injury and those without acute kidney injury were matched according to age, sex, ICU admission diagnosis, Simplified Acute Physiology Score II without renal and age components, and the propensity to develop acute kidney injury at each of the four matching time points. Setting:Cohort of 16 participating ICUs from the prospective Finnish Acute Kidney Injury study. Patients:Cohort of 2,719 consecutive patients with either emergency admission or elective postsurgical patients with an expected ICU stay greater than 24 hours. Interventions:None. Measurements and Main Results:Of the 2,719 patients included in the study, acute kidney injury developed in 1,081 patients (39.8%) according to the Kidney Disease: Improving Global Outcomes—definition during ICU treatment on days 1–5. Of these, 477 patients were successfully matched to 477 patients who did not develop acute kidney injury. The 90-day mortality of the matched patients with acute kidney injury was 125 of 477 (26.2%) compared with 84 of 477 (17.6%) for their matched controls without acute kidney injury. Thus, the absolute excess 90-day mortality attributable to acute kidney injury was estimated at 8.6 percentage points (95% CI, 2.6–17.6 percentage points). The population attributable risk (95% CI) of 90-day mortality associated with acute kidney injury was 19.6% (10.3–34.1%). Conclusions:In general ICU patients, the absolute excess 90-day mortality statistically attributable to acute kidney injury is substantial (8.6%), and the population attributable risk was nearly 20%. Our findings are useful in planning suitably powered future clinical trials to prevent and treat acute kidney injury in critically ill patients.

Influence of the injection site (L2/3 or L3/4) and the posture of the vertebral column on selective spinal anesthesia for ambulatory knee arthroscopy.

Background:u2002 We tested the hypothesis that selective spinal anesthesia for ambulatory knee arthroscopy can be accomplished with a small dose of bupivacaine at the L3/4 interspace with or without a head‐down tilt of 5° when the patients were in the lateral decubitus position.

Association of oliguria with the development of acute kidney injury in the critically ill

Urine output (UO) criterion may increase the sensitivity of the definition of acute kidney injury (AKI). We determined whether the empirically derived definition for oliguria (<0.5u2009ml/kg/h) is independently associated with adverse outcome. Data analysis included hourly recorded UO from the prospective, multicenter FINNAKI study conducted in 16 Finnish intensive care units. Confounder-adjusted association of oliguria of different severity and duration primarily with the development of AKI defined by creatinine criterion (Cr-AKI) or renal replacement therapy (RRT) was assessed. Secondarily, we determined the association of oliguria with 90-day mortality. Of the 1966 patients analyzed for the development of AKI, 454 (23.1%) reached this endpoint. Within this AKI cohort, 312 (68.7%) developed Cr-AKI, 21 (4.6%) commenced RRT without Cr-AKI, and 121 (26.7%) commenced RRT with Cr-AKI. Episodes of severe oliguria (<0.1u2009ml/kg/h) for more than 3u2009h were independently associated with the development of Cr-AKI or RRT. The shortest periods of consecutive oliguria independently associated with an increased risk for 90-day mortality were 6-12u2009h of oliguria from 0.3 to <0.5u2009ml/kg/h, over 6u2009h of oliguria from 0.1 to <0.3u2009ml/kg/h, and severe oliguria lasting over 3u2009h. Thus, our findings underlie the importance of hourly UO measurements.Kidney International advance online publication, 9 September 2015; doi:10.1038/ki.2015.269.