Accuracy of point-of-care serum creatinine devices for detecting patients at risk of contrast-induced nephropathy: a critical overview

Performance evaluation of all analytes on the epoc® Blood Analysis System for use in hospital surgical and intensive care units

Objective

To evaluate the performance of the epoc hand-held analyzer against the RAPIDPoint 500 blood gas analyzer and laboratory analyzers where applicable.

Methods

Venous or arterial whole blood samples collected in balanced heparinized syringes were obtained from 69 patients (35 females, 34 males) predominantly (77%) from the surgical unit and intensive care unit (ICU). Method comparison was performed for all analytes on the epoc System against the RAPIDPoint 500 Blood gas analyzer or laboratory analyzers where applicable. Results: Mean bias was <5% for blood gases, electrolytes, lactate and glucose. Hematocrit showed a bias of -6.76% (95% CI ​= ​-8.91, - 4.61) compared to the HemataSTAT-II method, whereas calculated total hemoglobin showed a bias of 1.51% (95% CI ​= ​-1.04, 4.06) against the Sysmex XN-10 hematology analyzer. Creatinine showed the largest bias relative to laboratory analyzers, Abbott Architect c8000 Jaffe method (13.54%, 95% CI ​= ​5.43, 21.65) and Roche Cobas c702 enzymatic method (30.01%, 95% CI ​= ​12.64, 47.38). Conclusions: The epoc system is fit for use in the surgical and ICU setting for the measurement of all analytes except for creatinine.

Pilot study determining the feasibility of implementing the Disadvantaged Populations eGFR Epidemiology Study (DEGREE) protocol, point-of-care field measurements and a new module on risk factors for chronic kidney disease of unknown origin in Hispanic outdoor workers

BACKGROUND

To field test the Disadvantaged Populations eGFR Epidemiology (DEGREE) protocol, outdoor point-of-care (POC) testing for serum creatinine, and a new risk factor module on chronic kidney disease of undetermined origin (CKDu) in U.S. outdoor Hispanic workers.

METHODS

Fifty workers were interviewed in Houston (TX). DEGREE and CKDu questionnaires were completed indoors. Anthropometrics and paired blood samples for POC and laboratory assay were completed outdoors over two periods (November-December 2017, April-May 2018).

RESULTS

Administration of DEGREE and CKDu questionnaires averaged 10 and 5 min, respectively, with all questions easily understood. We observed high correlations between POC and IDMS creatinine (r = 0.919) and BUN (r = 0.974). The POC device would disable testing when outdoor temperatures were above 85 °F or below 65 °F; this was adjustable.

CONCLUSIONS

Implementation of DEGREE and the new CKDu module was straightforward and well understood. The POC device performed well in the field, with some adjustment in methods when temperature readings were out of range.

Is point of care renal function testing reliable screening pre-IV contrast administration?

PURPOSE

Intravenous iodinated contrast is a commonly used diagnostic aid to improve image quality on computed tomography. There exists a small risk of post-contrast acute kidney injury in patients receiving IV contrast. One of the biggest risk factors for developing PC-AKI is the presence of pre-existing renal dysfunction, making it important to measure the renal function prior to contrast administration. Point of care (POC) devices offer a quick estimation of renal function, potentially improving workflows in radiology departments.

METHOD

Two POC devices were evaluated, the Nova StatSensor and Abbott iSTAT. Patients undergoing routine radiological investigations had blood collected and analysed by a POC method and the laboratory method (Beckman AU5800). The two values were analysed and compared. Renal function was calculated using eGFR via the CKD-EPI result. eGFR values were stratified as high risk (eGFR < 30), moderate risk (eGFR 30-59) and low risk (eGFR ≥ 60).

RESULTS

One hundred eighty-six patients were included in the study. One hundred one patients underwent the Abbott iSTAT analysis, 139 patients underwent Nova StatSensor analysis, and 53 had both. Statistical analysis revealed that the StatSensor R² value was 0.77, and coefficient variation was 10.65%. iSTAT had a R² value of 0.83 and coefficient variation of 7.36%. The POC devices did not miss any high-risk patients but underreported eGFR values in certain patients.

CONCLUSION

POC devices are moderately accurate at detecting renal impairment in patients undergoing radiological investigations. They seem to be a good screening tool; however, any low eGFR values should be further examined.

Incidence of Acute Kidney Injury After Computed Tomography Angiography±Computed Tomography Perfusion Followed by Thrombectomy in Patients With Stroke Using a Postprocedural Hydration Protocol

Background The risk of contrast-induced acute kidney injury (AKI) in patients with stroke receiving both computed tomography (CT) angiography and mechanical thrombectomy has been investigated only in small case series. No studies have investigated whether additional CT perfusion or chronic kidney disease (CKD) are associated with higher rates of AKI. Methods and Results Retrospective analysis of the AKI incidence in 1089 consecutive patients receiving CT angiography and mechanical thrombectomy from 2015 to 2017 and in subgroups with CKD (n=99) and CT perfusion (n=104) was performed. Patients received a standardized hydration protocol. Data on kidney function after mechanical thrombectomy were available in 1017 patients. A total of 59 (5.8%) patients developed AKI, and only 4 (6.8%) patients needed hemodialysis, all with known CKD. Patients with AKI significantly more often had known CKD (20.3% versus 8.4%, P=0.002), diabetes mellitus (33.9% versus 20.9%, P=0.018), and tandem occlusion (32.2% versus 16.2%, P=0.003) and a significantly higher in-hospital mortality (20.3% versus 7.0%, P<0.001) compared with patients without AKI. However, there were no significant independent predictors for AKI in multivariable logistic regression analysis. Sex (odds ratio [OR], 2.03; 95% CI, 1.17-3.52 [P=0.012]), higher National Institutes of Health Stroke Scale (OR, 1.10; 95% CI, 1.05-1.14 [P<0.001]), AKI (OR, 3.52; 95% CI, 1.63-7.64 [P=0.001]), diuretic use (OR, 1.80; 95% CI, 1.02-3.19), futile or incomplete recanalization (OR, 0.19; 95% CI, 0.09-0.40 [P<0.001]), and total volume of contrast agent volume (OR, 1.007; 95% CI, 1.002-1.011 [P=0.004]) were independently associated with in-hospital death. Two thirds of the patients with AKI died of severe brain damage and not AKI itself. Conclusions Post-contrast AKI rarely occurs in patients with stroke receiving a contrast agent for CT angiography/CT perfusion and subsequent mechanical thrombectomy. Patients with known CKD had higher rates of AKI and only these patients needed hemodialysis, but CKD was not independently associated with AKI or in-hospital mortality.

Computed Tomography with Intravenous Contrast is Not Associated with Development of Acute Kidney Injury in Severely Injured Pediatric Patients

Data for the incidence of acute kidney injury (AKI) related to intravenous contrast administration in the pediatric trauma population are limited. Obtaining a creatinine value before elective CT scans is a relatively accepted standard of care. We sought to determine whether there was any significant difference in the incidence of AKI between severely injured patients who received IV contrast and those who did not. We reviewed data from the trauma registry at our Level I pediatric trauma center. We limited the patients to severely injured pediatric traumas (<15 years old) directly transported from the scene of injury with a creatinine level measured on arrival. Two hundred and eleven patients were included in the study. AKI was defined by the criteria of the AKI Network. We then compared incidence of AKI in those who received a CT scan with IV contrast with those who did not receive IV contrast. The two groups were comparable in age, gender, Glasgow Coma Scale, Injury Severity Score, mean creatinine on arrival, and mean creatinine post–CT scan/arrival. There was no significant difference in AKI between the two. In a subgroup analysis of patients presenting in shock, there was no significant difference in AKI. Our study suggests that IV contrast is not associated with the development of AKI in severely injured pediatric trauma patients. Although obtaining a creatinine value before exposure is ideal, a CT scan with IV contrast in severely injured children should not be delayed to obtain a creatinine value.

Unadjusted point of care creatinine results overestimate acute kidney injury incidence during field testing in Guatemala

OBJECTIVE

Acute kidney injury (AKI) occurs at high rates among agricultural workers (12-33%) in tropical environments. Because of the remote locations affected, traditional laboratory services are often unavailable. In this study we compare point of care (POC) creatinine values to standardized laboratory values, and examine the effect of POC testing on the interpretation of AKI rates under tropical field conditions.

METHODS

Blood samples were collected from 104 sugarcane workers from two time points in January 2018 as a derivation cohort, and from 105 workers from February to April 2017 as a validation cohort. Finger stick and venipuncture samples were drawn at the end of a worker's shift to measure creatinine. Laboratory samples were tested in Guatemala City, Guatemala, in duplicate using the Jaffe Generation 2 method. An adjustment factor to improve agreement with serum creatinine was statistically derived and validated, and then used to determine impact on observed rates of acute kidney injury based on across shift changes in creatinine.

RESULTS

POC creatinine and serum creatinine measures showed that POC consistently overestimated the creatinine by an average of 22% (95% CI: 19.8%, 24.7%) and the disagreement appeared greater at higher values of serum creatinine. An adjustment factor of 0.7775 was applied, which led to significantly greater agreement between the two measures. Rates of AKI in the two combined groups fell from 72% before adjustment to 57% afterwards.

CONCLUSIONS

POC testing under tropical field conditions routinely overestimates creatinine compared to laboratory testing, which leads to overestimation of rates of acute kidney injury. The application of an adjustment factor significantly improved the accuracy of the POC value.

Post-contrast acute kidney injury - Part 1: Definition, clinical features, incidence, role of contrast medium and risk factors : Recommendations for updated ESUR Contrast Medium Safety Committee guidelines

Purpose

The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers.

Areas covered in part 1

Topics reviewed include the terminology used, the best way to measure eGFR, the definition of PC-AKI, and the risk factors for PC-AKI, including whether the risk with intravenous and intra-arterial contrast medium differs.

Key Points

• PC-AKI is the preferred term for renal function deterioration after contrast medium.

• PC-AKI has many possible causes.

• The risk of AKI caused by intravascular contrast medium has been overstated.

• Important patient risk factors for PC-AKI are CKD and dehydration.

Assessing the Risk of Contrast-Induced Nephropathy Using a Finger Stick Analysis in Recalls from Breast Screening: The CINFIBS Explorative Study

Purpose

To evaluate whether a handheld point-of-care (POC) device is able to predict and discriminate patients at potential risk of contrast-induced nephropathy (CIN) prior to iodine-based contrast media delivery.

Methods and Materials

Between December 2014 and June 2016, women undergoing contrast-enhanced spectral mammography (CESM) with an iodine-based contrast agent were asked to have their risk of CIN assessed by a dedicated POC device (StatSensor CREAT) and a risk factor questionnaire based on national guidelines. Prior to contrast injection, a venous blood sample was drawn to compare the results of POC with regular laboratory testing.

Results

A total of 351 patients were included; 344 were finally categorized as low risk patients by blood creatinine evaluation. Seven patients had a eGFR below 60 ml/min/1.73 m², necessitating additional preparation prior to contrast delivery. The POC device failed to categorize six out of seven patients (86%), leading to (at that stage) unwanted contrast administration. Two patients subsequently developed CIN after 2–5 days, which was self-limiting after 30 days.

Conclusion

The POC device tested was not able to reliably assess impairment of renal function in our patient cohort undergoing CESM. Consequently, we still consider classic clinical laboratory testing preferable in patients at potential risk for developing CIN.

The Accuracy of Point-of-Care Creatinine Testing in the Emergency Department

Objective. To determine the accuracy of Point-Of-Care testing (PoCT) creatinine values when compared to standard central laboratory testing (IDMS) and to demonstrate if and how a discrepancy could lead to improper risk stratification for contrast induced nephropathy (CIN). Methods. We conducted a descriptive retrospective chart review of patients seen in the Emergency Department of a single suburban, community, and academic medical center. We included patients who presented to the department between March 2013 and September 2014 who had blood samples analyzed by both PoCT and IDMS. Results. Mean IDMS creatinine values were 0.23 mg/dL higher when compared with i-Stat values. 95% of the time, the IDMS creatinine value was variable and ranged from −0.45 mg/dL to +0.91 mg/dL when compared to the i-Stat creatinine. When using i-Stat creatinine values to calculate GFR, 47 out of 156 patients had risk category variations compared to using the IDMS value. This affected 30.1% of the total eligible sample population (22.9% to 37.3% with 95% CI). Conclusion. We found a significant discrepancy between PoCT and IDMS creatinine values and found that this discrepancy could lead to improper risk stratification for CIN.

Academic College of Emergency Experts in India's INDO-US Joint Working Group and OPUS12 Foundation Consensus Statement on Creating A Coordinated, Multi-Disciplinary, Patient-Centered, Global Point-of-Care Biomarker Discovery Network

Biomarker science brings great promise to clinical medicine. This is especially true in the era of technology miniaturization, rapid dissemination of knowledge, and point-of-care (POC) implementation of novel diagnostics. Despite this tremendous progress, the journey from a candidate biomarker to a scientifically validated biomarker continues to be an arduous one. In addition to substantial financial resources, biomarker research requires considerable expertise and a multidisciplinary approach. Investigational designs must also be taken into account, with the randomized controlled trial remaining the “gold standard”. The authors present a condensed overview of biomarker science and associated investigational methods, followed by specific examples from clinical areas where biomarker development and/or implementation resulted in tangible enhancements in patient care. This manuscript also serves as a call to arms for the establishment of a truly global, well-coordinated infrastructure dedicated to biomarker research and development, with focus on delivery of the latest discoveries directly to the patient via point-of-care technology.