Contrast-associated acute kidney injury : does it really exist, and if so, what to do about it?

For decades, when contrast agents are administrated, physicians have been concerned because of the risk of inducing acute kidney injury (AKI). Recent literature questions the existence of AKI induced by contrast, but animal studies clearly showed harmful effects. The occurrence of contrast-associated AKI was likely overestimated in the past because of confounders for AKI. Several strategies have been investigated to reduce contrast-associated AKI but even for the most important one, hydration, there are conflicting data. Even if the occurrence rate of contrast-associated AKI is low, AKI is related to worse outcomes. Therefore, besides limiting contrast agent usage, general AKI preventive measurements should be applied in at-risk patients

AKI patients have worse long-term outcomes, especially in the immediate post-ICU period

Acute kidney injury (AKI) is associated with worse outcome in the acute phase of acute illness but also in the chronic phase. In a large Danish study in this issue of Critical Care, 1-year mortality was higher in patients with AKI than in patients without AKI. Mortality was most important during the first 50 days after admission to the intensive c are unit (ICU), whereas after 2 months the survival curves of patients with AKI and those of patients without AKI were similar. The reasons for this observation are not clear, but protracted critical illness and fragility after acute critical illness probably play important roles. Because we see more and more of these patients, they should be the focus of ICU research. Consequently, ICU and post-ICU care for these patients requires focus and a more integrated approach to the specific problems of these survivors of acute critical illness

Clinical review: Use of renal replacement therapies in special groups of ICU patients

Acute kidney injury (AKI) in ICU patients is typically associated with other severe conditions that require special attention when renal replacement therapy (RRT) is performed. RRT includes a wide range of techniques, each with specific characteristics and implications for use in ICU patients. In the present review we discuss a wide range of conditions that can occur in ICU patients who have AKI, and the implications this has for RRT. Patients at increased risk for bleeding should be treated without anticoagulation or with regional citrate anticoagulation. In patients who are haemodynamically unstable, continuous therapies are most often employed. These therapies allow slow removal of volume and guarantee a stable blood pH. In patients with cerebral oedema, continuous therapy is recommended in order to prevent decreased cerebral blood flow, which will lead to cerebral ischemia. Continuous therapy will also prevent sudden change in serum osmolality with aggravation of cerebral oedema. Patients with hyponatraemia, as in liver failure or decompensated heart failure, require extra attention because a rapid increase of serum sodium concentration can lead to irreversible brain damage through osmotic myelinolysis. Finally, in patients with severe lactic acidosis, RRT can be used as a bridging therapy, awaiting correction of the underlying cause. Especially in ICU patients who have severe AKI, treatment with RRT requires balancing the pros and cons of different options and modalities. Exact and specific guidelines for RRT in these patients are not available for most clinical situations. In the present article we provide an update on the existing evidence

Paving the way for precision medicine v2.0 in intensive care by profiling necroinflammation in biofluids

Current clinical diagnosis is typically based on a combination of approaches including clinical examination of the patient, clinical experience, physiologic and/or genetic parameters, high-tech diagnostic medical imaging, and an extended list of laboratory values mostly determined in biofluids such as blood and urine. One could consider this as precision medicine v1.0. However, recent advances in technology and better understanding of molecular mechanisms underlying disease will allow us to better characterize patients in the future. These improvements will enable us to distinguish patients who have similar clinical presentations but different cellular and molecular responses. Treatments will be able to be chosen more "precisely", resulting in more appropriate therapy, precision medicine v2.0. In this review, we will reflect on the potential added value of recent advances in technology and a better molecular understanding of necrosis and inflammation for improving diagnosis and treatment of critically ill patients. We give a brief overview on the mutual interplay between necrosis and inflammation, which are two crucial detrimental factors in organ and/or systemic dysfunction. One of the challenges for the future will thus be the cellular and molecular profiling of necroinflammation in biofluids. The huge amount of data generated by profiling biomolecules and single cells through, for example, different omic-approaches is needed for data mining methods to allow patient-clustering and identify novel biomarkers. The real-time monitoring of biomarkers will allow continuous (re)evaluation of treatment strategies using machine learning models. Ultimately, we may be able to offer precision therapies specifically designed to target the molecular set-up of an individual patient, as has begun to be done in cancer therapeutics

Acute kidney injury in burns: a story of volume and inflammation

Acute kidney injury occurs in approximately one-quarter to one-third of patients with major burn injury. Apart from the usual suspects – such as older age, severity of burn injury, sepsis and multiple organ dysfunction – volume overload probably has an important role in the pathogenesis of acute kidney injury

Low flow extracorporeal CO2 removal in ARDS patients : a prospective short-term crossover pilot study

Background: Lung protective mechanical ventilation (MV) is the corner stone of therapy for ARDS. However, its use may be limited by respiratory acidosis. This study explored feasibility of, effectiveness and safety of low flow extracorporeal CO2 removal (ECCO2R). Methods: This was a prospective pilot study, using the Abylcap (R) (Bellco) ECCO2R, with crossover off-on-off design (2-h blocks) under stable MV settings, and follow up till end of ECCO2R. Primary endpoint for effectiveness was a 20% reduction of PaCO2 after the first 2-h. Adverse events (AE) were recorded prospectively. We included 10 ARDS patients on MV, with PaO2/FiO(2) = 5 cmH(2)O, FiO(2) titrated to SaO(2) 88-95%, plateau pressure >= 28 cmH(2)O, and respiratory acidosis (pH < 7.25). Results: After 2-h of ECCO2R, 6 patients had a >= 20% decrease in PaCO2 (60%); PaCO2 decreased 28.4% (from 58.4 to 48. 7 mmHg, p = 0.005), and pH increased (1.59%, p = 0.005). ECCO2R was hemodynamically well tolerated. During the whole period of ECCO2R, 6 patients had an AE (60%); bleeding occurred in 5 patients (50%) and circuit thrombosis in 3 patients (30%), these were judged not to be life threatening. Conclusions: In ARDS patients, low flow ECCO2R significantly reduced PaCO2 after 2 h, Follow up during the entire ECCO2R period revealed a high incidence of bleeding and circuit thrombosis

Urinary chitinase 3-like protein 1 for early diagnosis of acute kidney injury : a prospective cohort study in adult critically ill patients

Background: Acute kidney injury (AKI) occurs frequently and adversely affects patient and kidney outcomes, especially when its severity increases from stage 1 to stages 2 or 3. Early interventions may counteract such deterioration, but this requires early detection. Our aim was to evaluate whether the novel renal damage biomarker urinary chitinase 3-like protein 1 (UCHI3L1) can detect AKI stage >= 2 more early than serum creatinine and urine output, using the respective Kidney Disease vertical bar Improving Global Outcomes (KDIGO) criteria for definition and classification of AKI, and compare this to urinary neutrophil gelatinase-associated lipocalin (UNGAL). Methods: This was a translational single-center, prospective cohort study at the 22-bed surgical and 14-bed medical intensive care units (ICU) of Ghent University Hospital. We enrolled 181 severely ill adult patients who did not yet have AKI stage >= 2 based on the KDIGO criteria at time of enrollment. The concentration of creatinine (serum, urine) and CHI3L1 (serum, urine) was measured at least daily, and urine output hourly, in the period from enrollment till ICU discharge with a maximum of 7 ICU-days. The concentration of UNGAL was measured at enrollment. The primary endpoint was the development of AKI stage >= 2 within 12 h after enrollment. Results: After enrollment, 21 (12 %) patients developed AKI stage >= 2 within the next 7 days, with 6 (3 %) of them reaching this condition within the first 12 h. The enrollment concentration of UCHI3L1 predicted the occurrence of AKI stage >= 2 within the next 12 h with a good AUC-ROC of 0.792 (95 % CI: 0.726-0.849). This performance was similar to that of UNGAL (AUC-ROC of 0.748 (95 % CI: 0.678-0.810)). Also, the samples collected in the 24-h time frame preceding diagnosis of the 1st episode of AKI stage >= 2 had a 2.0 times higher (95 % CI: 1.3-3.1) estimated marginal mean of UCHI3L1 than controls. We further found that increasing UCHI3L1 concentrations were associated with increasing AKI severity. Conclusions: In this pilot study we found that UCHI3L1 was a good biomarker for prediction of AKI stage >= 2 in adult ICU patients

Semicontinuous intra-abdominal pressure measurement using an intragastric Compliance catheter

OBJECTIVE: To compare intra-abdominal pressure (IAP) measurements obtained from an intragastric Compliance catheter with the pressure measured directly in the abdominal cavity. DESIGN AND SETTING: Prospective cohort study in an operating room of the Ghent University Hospital PATIENTS: Seven patients undergoing elective laparoscopic cholecystectomy. INTERVENTIONS: IAP was obtained from both an intragastric catheter and directly from the peritoneal cavity at 1-minute intervals in patients undergoing elective cholecystectomy and compared using Bland-Altman analysis. MEASUREMENTS AND RESULTS: In 156 paired measurements obtained from 7 patients the mean difference between IAPgastric and IAPref was 0.12+/-0.70 mmHg (95% CI 0.01-0.23). CONCLUSIONS: IAP measured using an intragastric Compliance catheter reliably reflects the reference IAP in patients undergoing laparoscopic cholecystectomy