Risk factors for radiocontrast nephropathy after emergency department contrast-enhanced computerized tomography

Development and Validation of a Risk Model for Predicting Contrast-Associated Acute Kidney Injury in Patients With Cancer: Evaluation in Over 46,000 CT Examinations

BACKGROUND. Patients with cancer undergo frequent CT examinations with iodinated contrast media and may be uniquely predisposed to contrast-associated acute kidney injury (CA-AKI). OBJECTIVE. The purpose of this study was to develop and validate a model for predicting the risk of CA-AKI after contrast-enhanced CT in patients with cancer. METHODS. This retrospective study included 25,184 adult patients (12,153 men, 13,031 women; mean age, 62.3 ± 13.7 [SD] years) with cancer who underwent 46,593 contrast-enhanced CT examinations between January 1, 2016, and June 20, 2020, at one of three academic medical centers. Information was recorded regarding demographics, malignancy type, medication use, baseline laboratory values, and comorbid conditions. CA-AKI was defined as a 0.3-mg/dL or greater increase in serum creatinine level from baseline within 48 hours after CT or a 1.5-fold or greater increase in the peak measurement within 14 days after CT. Multivariable models accounting for correlated data were used to identify risk factors for CA-AKI. A risk score for predicting CA-AKI was generated in a development set (n = 30,926) and tested in a validation set (n = 15,667). RESULTS. CA-AKI occurred after 5.8% (2682/46,593) of CT examinations. The final multivariable model for predicting CA-AKI included hematologic malignancy, diuretic use, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, chronic kidney disease (CKD) stage 3a, CKD stage 3b, CKD stage 4 or 5, serum albumin level less than 3.0 g/dL, platelet count less than 150 × 103/μL, 1+ or greater proteinuria on baseline urinalysis, diabetes mellitus, heart failure, and contrast medium volume 100 mL or greater. A risk score (range, 0-53 points) was generated with these variables. The most points (13) were for CKD stage 4 or 5 and for albumin level less than 3 g/dL. The frequency of CA-AKI progressively increased in higher risk categories. For example, in the validation set, CA-AKI occurred after 2.2% of CT examinations in the lowest risk category (score ≤ 4) and after 32.7% of CT examinations in the highest risk category (score ≥ 30). The Hosmer-Lemeshow test result indicated that the risk score was a good fit (p = .40). CONCLUSION. A risk model in which readily available clinical data are used to predict the likelihood of CA-AKI after contrast-enhanced CT in patients with cancer was developed and validated. CLINICAL IMPACT. The model may help facilitate appropriate implementation of preventive measures in the care of patients at high risk of CA-AKI.

Illuminating the Use of Trauma Whole-Body CT Scan During the Global Contrast Shortage

BACKGROUND

Use of whole-body CT scan (WBCT) is widespread in the evaluation of traumatically injured patients and may be associated with improved survival. WBCT protocols include the use of IV contrast unless there is a contraindication. This study tests the hypothesis that using plain WBCT scan during the global contrast shortage would result in greater need for repeat contrast-enhanced CT, but would not impact mortality, missed injuries, or rates of acute kidney injury (AKI).

STUDY DESIGN

All trauma encounters at an academic level-I trauma center between March 1, 2022 and June 24, 2022, excluding burns and prehospital cardiac arrests, were reviewed. Imaging practices and outcomes before and during contrast shortage (beginning May 3, 2022) were compared.

RESULTS

The study population included 1,109 consecutive patients (72% male), with 890 (80%) blunt and 219 (20%) penetrating traumas. Overall, 53% of patients underwent WBCT and contrast was administered to 73%. The overall rate of AKI was 6% and the rate of renal replacement therapy (RRT) was 1%. Contrast usage in WBCT was 99% before and 40% during the shortage (p < 0.001). There was no difference in the rate of repeat CT scans, missed injuries, AKI, RRT, or mortality.

CONCLUSIONS

Trauma imaging practices at our center changed during the global contrast shortage; the use of contrast decreased despite the frequency of trauma WBCT scans remaining the same. The rates of AKI and RRT did not change, suggesting that WBCT with contrast is insufficient to cause AKI. The missed injury rate was equivalent. Our data suggest similar outcomes can be achieved with selective IV contrast use during WBCT.

The Incidence and Associated Risk Factors of Contrast-Induced Nephropathy after Contrast-Enhanced Computed Tomography in the Emergency Setting: A Systematic Review

Iodinated contrast media (ICM) during contrast-enhanced computed tomography (CECT) in the emergency department (ED) is essential to diagnose acute conditions, despite risks of contrast-induced nephropathy (CIN) development and its associated complications. This systematic review aims to evaluate the incidence of CIN and CIN-induced complications, and to explore the relevance of classical risk factors for CIN among ED patients receiving ICM. PubMed, Cochrane, and Web of Science were used on 30 August 2021 to search for peer-reviewed English articles reporting on CIN incidence among ED patients aged ≥18 years who underwent an intravenous CECT. The inclusion criteria included studies that were in English, peer-reviewed, and involved ED patients aged ≥18 years who underwent single intravenous CECT. Studies on intra-arterial procedures and preventive strategies, meta-analyses, clinical guidelines, review articles, and case reports were excluded. The JBI critical appraisal checklist was applied to assess the risk of bias. In total, 18 studies were included wherein 15 were retrospective studies while three were prospective studies. We found a relatively higher CIN incidence in the ED, with variations owing to the CIN definitions. Several classical risk factors including acute hypotension remain linked to CIN onset in ED settings unlike factors such as age and diabetes. While risk of adverse renal events due to CIN is low, there is higher risk of CIN-induced mortality in the ED. Therefore, with the higher incidence of CIN and CIN-induced mortality rates in the ED, ICM administration during CECT in the ED should still be clinically justified after assessing both benefits and risks.

Contrast associated nephropathy after intravenous administration: what is the magnitude of the problem?

Intravenous contrast media (CM) is often used in clinical practice to enhance CT scan imaging. For many years, contrast-induced nephropathy (CIN) was thought to be a common occurrence and to result in dire consequences. When treating patients with abnormal renal function, it is not unusual that clinicians postpone, cancel, or replace contrast-enhanced imaging with other, perhaps less informative tests. New studies however have challenged this paradigm and the true risk attributable to intravenous CM for the occurrence of CIN has become debatable. In this article, we review the latest relevant medical literature and aim to provide an evidence-based answer to questions surrounding the risk, outcomes, and potential mitigation strategies of CIN after intravenous CM administration.

Risk factors for severe acute kidney injury among patients with rhabdomyolysis

BACKGROUND

Acute kidney injury (AKI) is a life-threatening complication of rhabdomyolysis (RM). The aim of the present study was to assess patients at high risk for the occurrence of severe AKI defined as stage II or III of KDIGO classification and in-hospital mortality of AKI following RM.

METHODS

We performed a retrospective study of patients with creatine kinase levels > 1000 U/L, who were admitted to the West China Hospital of Sichuan University between January 2011 and March 2019. The sociodemographic, clinical and laboratory data of these patients were obtained from an electronic medical records database, and univariate and multivariate regression analyses were subsequently conducted.

RESULTS

For the 329 patients included in our study, the incidence of AKI was 61.4% and the proportion of stage I, stage II, stage III were 18.8, 14.9 and 66.3%, respectively. The overall mortality rate was 19.8%; furthermore, patients with AKI tended to have higher mortality rates than those without AKI (24.8% vs. 11.8%; P < 0.01). The clinical conditions most frequently associated with RM were trauma (28.3%), sepsis (14.6%), bee sting (12.8%), thoracic and abdominal surgery (11.2%) and exercise (7.0%). Furthermore, patients with RM resulting from sepsis, bee sting and acute alcoholism were more susceptible to severe AKI. The risk factors for the occurrence of stage II-III AKI among RM patients included hypertension (OR = 2.702), high levels of white blood cell count (OR = 1.054), increased triglycerides (OR = 1.260), low level of high-density lipoprotein cholesterol (OR = 0.318), elevated serum phosphorus (OR = 5.727), 5000<CK ≤ 10,000 U/L (OR = 2.617) and CK>10,000 U/L (OR = 8.093). Age ≥ 60 years (OR = 2.946), sepsis (OR = 3.206) and elevated prothrombin time (OR = 1.079) were independent risk factors for in-hospital mortality in RM patients with AKI.

CONCLUSIONS

AKI is independently associated with mortality in patients with RM, and several risk factors were found to be associated with the occurrence of severe AKI and in-hospital mortality. These findings suggest that, to improve the quality of medical care, the early prevention of AKI should focus on high-risk patients and more effective management.

Risk Prediction for Contrast-Induced Nephropathy in Cancer Patients Undergoing Computed Tomography under Preventive Measures

Background

Contrast-induced nephropathy (CIN) is a major cause of acute kidney injury in chronic kidney disease. Many cancer patients have risk factors for CIN and frequently undergo contrast-enhanced computed tomography (CECT). We aimed to develop a risk prediction model for CIN in cancer patients undergoing CECT.

Methods

Between 2009 and 2017, 2,240 cancer patients with estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m² who underwent CECT with CIN preventive measures were included in a development cohort. Primary outcome was development of CIN, defined as 25% increase in serum creatinine within 2-6 days after contrast exposure. A prediction model was developed using logistic regression analysis. The model was evaluated for prognostic utility in an independent cohort (N = 555).

Results

Overall incidence of CIN was 2.5% (55/2,240). In multivariable analysis, eGFR, diabetes mellitus, and serum albumin level were identified as independent predictors of CIN. A prediction model including eGFR, serum albumin level, and diabetes mellitus was developed, and risk scores ranged from 0 to 6 points. The model demonstrated fair discriminative power (C statistic = 0.733, 95% confidence interval [CI] 0.656-0.810) and good calibration (calibration slope 0.867, 95% Cl 0.719-1.015). In the validation cohort, the model also demonstrated fair discriminative power (C statistic = 0.749, 95% CI 0.648-0.849) and good calibration (calibration slope 0.974, 95% CI 0.634-1.315).

Conclusions

The proposed model has good predictive ability for risk of CIN in cancer patients with chronic kidney disease. This model can aid in risk stratification for CIN in patients undergoing CECT.

Diabetes Mellitus: fator de risco para toxicidade de medicamentos

RESUMO Objetivo Avaliar o efeito do antibiótico gentamicina em modelo experimental na presença de Diabetes Mellitus por meio da função renal e perfil oxidativo. Método Ratos Wistar, adultos, machos, foram distribuídos nos grupos: Citrato; Gentamicina (Genta), (gentamicina 100 mg/kg de peso corporal, 1 vez ao dia, intraperitoneal, i.p., 5 dias); DM (60 mg/kg de STZ, intravenosa, i.v., dose única, diluída em tampão citrato) e DM+Genta. Foram avaliados os parâmetros fisiológicos, a função renal (clearance de creatinina), a lesão oxidativa (peróxidos e substâncias reativas ao ácido tiobarbitúrico − TBARS urinários) e a hemodinâmica renal. Resultados O grupo Diabetes Mellitus apresentou hiperglicemia crônica, associada à perda de peso corporal, polifagia, polidipsia e poliúria, além de redução da função renal, com aumento na excreção de metabólitos oxidativos. A administração de gentamicina induziu a redução do fluxo sanguíneo renal e o aumento da resistência vascular renal em ratos saudáveis. A associação do Diabetes Mellitus com gentamicina resultou em redução adicional na função renal e elevação de metabólitos oxidativos, com aumento de resistência vascular renal. Conclusão A existência de Diabetes Mellitus determinou a elevação da nefrotoxicidade da gentamicina e se confirmou como fator de risco para nefrotoxicidade de medicamentos.

Serum and Tissue HIF-2 Alpha Expression in CIN, N-Acetyl Cysteine, and Sildenafil-Treated Rat Models: An Experimental Study

Background and Objectives: Contrast-induced nephropathy (CIN), is acute renal damage due to contrast agents. This study is conducted to evaluate serum and renal heterodimeric nuclear transcription factor (HIF)-2 alpha levels and its tissue expression in contrast-induced nephropathy, and in N-acetyl cysteine (NAC)-and Sildenafil-treated rat models. Materials/Methods: This randomized, controlled, interventional animal study was conducted on Wistar rats. Rats (n = 36) were randomly assigned to four groups: control (n = 9), CIN group (n = 9), CIN + NAC group (n = 9), and sildenafil (n = 9). The rat model was used to form iohexol-originated CIN. During the modeling, prophylactic treatment was performed at the 24th and 48th h. After 48 h of modeling, blood, urine, and tissue samples were obtained for biochemical analyses. HIF-2-α levels were measured in renal tissue, serum, and urine samples. Renal sections were also performed for histopathologic and immunohistochemical evaluations of renal injury and HIF-2-α expression. Results: In the CIN model, HIF-2α levels and other biochemical parameters were significantly increased (p < 0.01). Both sildenafil and NAC efficiently decreased renal damage due to contrast agents, as shown in histopathologic examinations (p < 0.05). Similarly, after treatment with sildenafil and NAC, HIF-2α levels were significantly decreased (p < 0.05). Conclusions: The current study shows that serum and tissue HIF-2α levels decrease in CIN. Besides, the levels and tissue expression of HIF-2α decrease with both NAC and sildenafil treatments. With further studies, HIF-2α can be investigated as a biomarker of CIN and can be used in the follow-up of patients with CIN.

The Economic Value of Hybrid Single-photon Emission Computed Tomography With Computed Tomography Imaging in Pulmonary Embolism Diagnosis

Objective

The objective was to quantify the potential economic value of single‐photon emission computed tomography (SPECT) with computed tomography (CT; SPECT/CT) versus CT pulmonary angiography (CTPA), ventilation–perfusion (V/Q) planar scintigraphy, and V/Q SPECT imaging modalities for diagnosing suspected pulmonary embolism (PE) patients in an emergency setting.

Methods

An Excel‐based simulation model was developed to compare SPECT/CT versus the alternate scanning technologies from a payer's perspective. Clinical endpoints (diagnosis, treatment, complications, and mortality) and their corresponding cost data (2016 USD) were obtained by performing a best evidence review of the published literature. Studies were pooled and parameters were weighted by sample size. Outcomes measured included differences in 1) excess costs, 2) total costs, and 3) lives lost per annum between SPECT/CT and the other imaging modalities. One‐way (±25%) sensitivity and three scenario analyses were performed to gauge the robustness of the results.

Results

For every 1,000 suspected PE patients undergoing imaging, expected annual economic burden by modality was found to be 3.2 million (SPECT/CT), 3.8 million (CTPA), 5.8 million (planar), and 3.6 million (SPECT) USD, with a switch to SPECT/CT technology yielding per‐patient‐per‐month cost savings of $51.80 (vs. CTPA), $213.80 (vs. planar), and $36.30 (vs. SPECT), respectively. The model calculated that the incremental number of lives saved with SPECT/CT was six (vs. CTPA) and three (vs. planar). Utilizing SPECT/CT as the initial imaging modality for workup of acute PE was also expected to save $994,777 (vs. CTPA), $2,852,014 (vs. planar), and $435,038 (vs. SPECT) in “potentially avoidable”’ excess costs per annum for a payer or health plan.

Conclusion

Compared to the currently available scanning technologies for diagnosing suspected PE, SPECT/CT appears to confer superior economic value, primarily via improved sensitivity and specificity and low nondiagnostic rates. In turn, the improved diagnostic accuracy accords this modality the lowest ratio of expenses attributable to potentially avoidable complications, misdiagnosis, and underdiagnosis.

Prospective ECG-triggering cardiac CT for infants with complex congenital heart disease using low-dose contrast medium, low tube voltage, and adaptive statistical iterative reconstruction

AIM

To demonstrate the clinical value of prospective electrocardiography (ECG)-triggered cardiac computed tomography (CT) with low concentration contrast medium, low tube voltage, and adaptive statistic iterative reconstruction (ASIR) to reduce both radiation and contrast dose in examining infants with complex congenital heart disease (CHD).

MATERIALS AND METHODS

Forty-four consecutive infants (19 male, 25 female, age: 8.06±4.33 months, weight: 7.31±1.36 kg) with complex CHD underwent prospective ECG-triggered low-dose cardiac CT using 80 kVp and 120 mA. The contrast agent was iodixanol (270 mg iodine/ml, Visipaque, GE Healthcare, Co. Cork, Ireland). Cardiac CT images were reconstructed with 70% ASIR. The quantitative CT image quality was assessed by image noise in adipose tissue and contrast-to-noise ratio (CNR) in the aorta. The qualitative image analysis was performed on a five-point grading scale by two independent reviewers and interobserver variability was calculated. The results of 32 CT examinations were also compared with the available surgical results for diagnostic accuracy evaluation.

RESULTS

The effective dose was 0.55±0.10 mSv for the patient population. The iodine load was 3.95±0.73 g iodine. Image noise in adipose tissue was 16.24±1.42 HU and CNR in aorta was 21.90±7.10. All images were acceptable for diagnosis with an average score of 4.52±0.38 and good agreement between reviewers (kappa=0.75). Compared to the surgery results in 32 cases, CT was 97% and 88% accurate diagnosing extracardiac and intracardiac defects, respectively.

CONCLUSION

Prospective ECG-triggered cardiac CT using 80 kVp, low-concentration iodinated contrast agent (270 mg iodine/ml) and 70% ASIR reconstruction provides excellent image quality and accurate diagnosis for complex congenital heart disease in infants with reduced contrast medium dose and low radiation dose.

Association Between Acute Kidney Disease and Intravenous Dye Administration in Patients With Acute Stroke: A Population-Based Study

BACKGROUND AND PURPOSE

Computed tomographic angiography and conventional angiography provide timely vascular anatomic information in patients with stroke. However, iodinated contrast dye may cause acute kidney injury (AKI). Within a large, biracial population, we examined in-hospital incidence of new or worsening kidney disease in patients with stroke and its association with administration of intravenous dye.

METHODS

All adult residents of the Greater Cincinnati/Northern Kentucky region with acute ischemic stroke or intracerebral hemorrhage who presented to an emergency department in 2010 were included. Prevalence of unsuspected kidney disease at the time of emergency department presentation and the incidence of AKI after admission in 2 groups of patients-those who did and those who did not receive intravenous dye-were determined.

RESULTS

In 2010, 2299 patients met inclusion criteria (89% ischemic stroke and 11% intracerebral hemorrhage); mean age 69 years (SD 15), 22% black, and 54% women. Among these patients, 37% had kidney disease at baseline, including 22% (516/2299) in whom this was unsuspected. Two percent (2%; 15/853) of patients with baseline kidney disease developed AKI during the hospital stay. Of those with no baseline kidney disease, 1% (14/14 467) developed AKI. There was no association between dye administration and new or worsening kidney disease.

CONCLUSIONS

Although 22% of patients in the Greater Cincinnati/Northern Kentucky stroke population had unsuspected kidney disease, the incidence of new or worsening kidney disease was low, and AKI was not associated with dye administration. These findings confirm single-center reports that the risk of severe renal complications after contrast dye is small.

Risk factors for contrast-induced nephropathy and their association with mortality in patients with blunt splenic injuries

BACKGROUND

Although angioembolization increases the success rate of non-operative management in patients with blunt splenic injuries (BSI), the issue of contrast-induced nephropathy (CIN) due to serial administration of contrast medium remains unclear. We aimed to examine the risk factors of CIN and their clinical effect on mortality in patients with BSI.

METHOD

We retrospectively studied the complete data on 377 trauma patients with BSI who survived more than 48 h between July 2003 and June 2015. CIN was defined as the relative (≥25%) or absolute (≥0.5 mg/dL) increase in serum creatinine within 48 h after contrast administration. A multivariate logistic regression analysis was conducted to identify the independent predictors of CIN and mortality.

RESULTS

CIN was independently associated with body mass index (BMI) ≥ 30 kg/m² (odds ratio [OR]: 3.25, 95% confidence interval [CI]: 1.20-8.76), injury severity score (ISS) ≥ 25 (OR: 6.08, 95% CI: 2.76-13.53), and 24-h hemoglobin (Hb) < 10 g/dL (OR: 3.16, 95% CI: 1.46-6.81). CIN (OR: 19.04, 95% CI: 6.15-58.94) and diabetes (OR: 3.43, 95% CI: 1.04-11.26) were also identified as independent predictors for mortality.

CONCLUSION

In this study, we found that BMI ≥ 30 kg/m², ISS ≥ 25, and 24-h Hb < 10 g/dL were independent risk factors for the occurrence of CIN in patients with BSI. However, angioembolization was not identified to be an independent risk factor for CIN. In addition, CIN and diabetes mellitus were identified as independent risk factors for mortality in patients with BSI.

Application of low dose radiation and low concentration contrast media in enhanced CT scans in children with congenital heart disease

OBJECTIVE

The aim of this study was to explore the feasibility of using low dose radiation and low concentration contrast media in enhanced CT examinations in children with congenital heart disease.

MATERIALS AND METHODS

Ninety patients with congenital heart disease were randomly divided into three groups of 30 patients each who underwent contrast-enhanced cardiac scans on a Discovery CT750 HD scanner. Group A received 270 mg I/mL iodixanol, and group B received 320 mg I/mL iodixanol contrast media and was scanned with prospective ECG triggering mode. Group C received 320 mg I/mL iodixanol and was scanned with conventional retrospective ECG gating mode. The same weight-based contrast injection protocol was used for all three groups. Images were reconstructed using a 30% adaptive statistical iterative reconstruction (ASIR) algorithm and a 50% ASIR in groups A and B and a 30% ASIR in group C. The subjective and objective image quality evaluations, diagnostic accuracies, radiation doses and amounts of contrast media in the three groups were measured and compared.

RESULTS

All images in the three groups met the diagnostic requirements, with the same diagnostic accuracy and image quality scores greater than 3 in a 4-point scoring system. However, ventricular enhancement and the objective noise, signal-to-noise ratio, contrast-to-noise ratio and subjective image quality scores in group C were better than those in groups A and B (all P<.001). The effective radiation dose in groups A and B was 84% lower than that in group C (P<.001); group A received the lowest contrast dose (14% lower than that of groups B and C).

CONCLUSION

Enhanced CT scan images with low dose radiation and low concentration contrast media can meet the diagnostic requirements for examining children with congenital heart disease while reducing the potential risk of radiation damage and contrast-induced nephropathy.

Preventing and Treating Acute Kidney Injury Among Hospitalized Patients with Cirrhosis and Ascites: A Narrative Review

Acute kidney injury in the setting of ascites and cirrhosis is a medical emergency characterized by significant morbidity and mortality. Clinicians other than gastroenterologists are often the front line against acute kidney injury for patients with ascites. Owing to the specifics of cirrhotic physiology, the treatment and prevention of acute kidney injury in the setting of ascites has unique features, widespread knowledge of which will benefit our patients with cirrhosis. Early detection and treatment of infection, maximization of cardiac output, and avoidance of medications that limit cardiorenal adaptations to arterial underfilling are part of a multipronged strategy to protect the renal function of our patients with cirrhosis and ascites.

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.

Intravenous Contrast Medium Administration for Computed Tomography Scan in Emergency: A Possible Cause of Contrast-Induced Nephropathy

The goal of this study was to assess risk for CIN after CT Scan during an emergency and to identify risk factors for the patient. Prospective review of all patients admitted to the emergency room (ER) of the Teaching Hospital of Lomé (Togo) during a 2-year period. CIN was defined as an increase in serum creatinine by 0.5 mg/dL from admission after undergoing CT Scan with intravenous contrast. A total of 620 patients underwent a CT Scan in the emergency room using intravenous contrast and 672 patients took the CT Scan without intravenous contrast. Out of the patients who received intravenous contrast for CT Scan, three percent of them developed CIN during their admission. Moreover, upon discharge no patient had continued renal impairment. No patient required dialysis during their admission. The multivariate analysis of all patients who had serial creatinine levels (including those who did not receive any contrast load) shows no increased risk for acute kidney injury associated intravenous contrast (odds ratio = 0.619, p value = 0.886); only diabetes remains independent risk factor of acute kidney injury (odds ratio = 6.26, p value = 0.031).

Contrast-induced nephropathy in patients with active cancer undergoing contrast-enhanced computed tomography

PURPOSE

This study was performed to measure the incidence and identify potential predictors of contrast-induced nephropathy (CIN) in cancer patients without chronic kidney disease and with normal or near-normal baseline serum creatinine measures who underwent contrast-enhanced computed tomography (CECT). Severity of CIN was reported based on the RIFLE (risk, injury, failure, loss of kidney function, and end-stage renal disease) classification of acute kidney injury.

METHODS

A retrospective analysis was performed on 820 cancer patients who presented at our emergency department from October 2014 to March 2015. CIN was defined as an increase in creatinine concentration of ≥0.5 mg/dL or ≥25 % above baseline that occurred 48 to 72 h after CECT.

RESULTS

The incidence of CIN was 8.0%. Serial CT examination [odds ratio (OR) 4.09; 95% confidence interval (CI) 1.34-12.56], hypotension before the CT scan (OR 3.95; 95% CI 1.77-8.83), liver cirrhosis (OR 2.82; 95% CI 1.06-7.55), BUN/creatinine >20 (OR 2.54; 95% CI 1.44-4.46), and peritoneal carcinomatosis (OR 1.75; 95% CI 1.01-3.00) were independently associated with CIN. Of 66 CIN patients, 44 met any of the severity criteria of the RIFLE classification. Five of these patients died during hospitalization but only one death was related to renal failure.

CONCLUSIONS

Even when the baseline serum creatinine is ≤1.5 mg/dL, a significant portion of cancer patients are still at risk of CIN. Consecutive CECT examinations, hypotension before CT, liver cirrhosis, dehydration, and peritoneal carcinomatosis seem to predispose patients to CIN.

Coronary computed tomographic angiography in coronary artery bypass grafts: comparison between low-concentration Iodixanol 270 and Iohexol 350

OBJECTIVE

The aim of this study was to evaluate the feasibility of low-concentration iso-osmolar Iodixanol 270 compared with Iohexol 350 in patients with coronary artery bypass grafts (CABGs) undergoing coronary computed tomographic angiography (CCTA).

METHODS

A total of 80 consecutive patients undergoing CABG follow-up with the use of CCTA were prospectively enrolled, with 40 patients assigned to Iodixanol 270 and 40 patients assigned to Iohexol 350. In both groups, the contrast medium was injected at an injection rate of 4.5 mL/s in the patients with a body mass index of greater than 24 kg/m2 and 3.5 mL/s in the patients with a body mass index of 24 kg/m2 or lower. The contrast volume was determined by the flow rate and scan time. Image quality score and visualization of bypass grafts were evaluated. Subjective assessment of image quality for each coronary artery segment was determined using a 4-point grading scale by 2 reviewers, whereas objective evaluation of image quality was conducted by measuring the mean CT attenuation values (hounsfield unit [HU]) in terms of SD, contrast-noise ratio, and signal-noise ratio in the ascending aorta.

RESULTS

The mean (SD) contrast volume for the Iodixanol 270 and Iohexol 350 groups was 66.28 (12.00) and 64.98 (8.12) mL, respectively, with no significant difference (P = 0.57). The mean (SD) CT attenuation value in the Iodixanol 270 group was 414.72 (101.47), which was lower than in the Iohexol 350 group, which was 478.85 (108.73) (P = 0.01). The subjective image quality for the Iodixanol 270 group was superior to that for the Iohexol 350 group in the arterial graft vessels (P = 0.027), whereas there was no significant difference between the 2 groups in the venous graft vessels (P = 0.377). There was no significant difference in terms of SD of the ascending aorta, signal-noise ratio, and contrast-noise ratio between the 2 groups.

CONCLUSIONS

Low-concentration iso-osmolar Iodixanol 270 provides image quality comparable with that of Iohexol 350, allowing diagnostic CCTA follow-up of patients with CABGs.

Computed tomography scans with intravenous contrast: low incidence of contrast-induced nephropathy in blunt trauma patients

BACKGROUND

Computed tomography (CT) with intravenous (IV) contrast is an important step in the evaluation of the blunt trauma patient; however, the risk for contrast-induced nephropathy (CIN) in these patients still remains unclear. The goal of this study was to describe the rate of CIN in blunt trauma patients at a Level 1 trauma center and identify the risk factors of developing CIN.

METHODS

After internal review board approval, we reviewed our Level 1 trauma registry to identify blunt trauma patients admitted during a 1-year period. Chart review was used to identify patient demographics, creatinine levels, and vital signs. CIN was defined as an increase in creatinine by 0.5 mg/dL from admission after undergoing CT with IV contrast.

RESULTS

Four percent of patients developed CIN during their admission following receipt of IV contrast for CT; 1% had continued renal impairment on discharge. No patients required dialysis during their admission. Diabetic patients had an increased rate of CIN, with 10% rate of CIN during admission and 4% at discharge. In multivariate analysis, only preexisting diabetes and Injury Severity Score (ISS) of greater than 25 were independently associated with risk for CIN.

CONCLUSION

The rate of CIN in trauma patients following CT scan with IV contrast is low. Diabetes and ISS were independent risk factors of development of CIN in trauma patients.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III.

Comparison of short-term infusion regimens of N-acetylcysteine plus intravenous fluids, sodium bicarbonate plus intravenous fluids, and intravenous fluids alone for prevention of contrast-induced nephropathy in the emergency department

BACKGROUND

There is no evidence regarding the several short-term prophylaxis protocols for contrast-induced nephropathy (CIN) that may be most feasibly convenient in emergency settings.

OBJECTIVES

The purpose of this study was to compare the efficacies of short-term CIN prophylaxis protocols of normal saline, N-acetylcysteine (NAC) plus saline, and sodium bicarbonate plus saline in emergency department (ED) patients at moderate or high risk of CIN after receiving intravenous (IV) contrast agent.

METHODS

This single-center, randomized, nonblinded clinical trial was conducted in the ED with adult patients requiring contrast-enhanced computed tomography (CT). Patients with moderate to high risk of CIN according to the Mehran risk score, who consented to participate, were eligible. Patients with continuous renal replacement therapy or who reported contrast allergy were excluded. Enrolled patients were randomly assigned to receive 150 mg/kg NAC in 1000 mL of 0.9% sodium chloride (NaCl), 150 mEq of sodium bicarbonate in 1000 mL of 0.9% NaCl, or 1000 mL of IV saline infusion, all given at 350 mL/hr for 3 hours. All of the patients were administered less than 100 mL of nonionic, low-osmolality contrast agent. The primary outcome of CIN was defined as a 25% increase or a greater than 0.5 mg/dL increase in the serum creatinine level 48 to 72 hours later compared with the baseline measurement.

RESULTS

A total of 107 patients were randomized to NAC (n = 36), sodium bicarbonate (n = 36), and saline prophylaxis (n = 35). The mean age of the patients was 71 years (95% confidence interval [CI] = 65 to 77 years), and 58 (54.2%) were male. The groups were similar regarding baseline characteristics and nephropathy risks. Of the 16 (14.9%) patients who eventually developed CIN, seven (19.4%) were in the NAC plus saline group, four (11.1%) were in the sodium bicarbonate plus saline group, and five (14.2%) were in the saline group. There were no significant differences between the groups in terms of the prevention of CIN (p = 0.60).

CONCLUSIONS

None of the short-term protocols with normal saline, NAC, or sodium bicarbonate was superior in ED patients requiring contrast-enhanced CT who had a moderate or high risk of CIN.

Nephrotoxicity Of Polymyxin B: Experimental Study In Cells And Implications For Nursing Practice

The aim of the study was to characterize the cell damage mechanisms involved in the pathophysiology of cytotoxicity of polymyxin B in proximal tubular cells (LLC - PK1) and discuss about the nurses interventions to identify at risk patients and consider prevention or treatment of nephrotoxicity acute kidney injury. This is a quantitative experimental in vitro study, in which the cells were exposed to 375μM polymyxin B sulfate concentration. Cell viability was determined by exclusion of fluorescent dyes and morphological method with visualization of apoptotic bodies for fluorescence microscopy. Cells exposed to polymyxin B showed reduced viability, increased number of apoptotic cells and a higher concentration of the enzyme lactate dehydrogenase. The administration of polymyxin B in vitro showed the need for actions to minimize adverse effects such as nephrotoxicity.


N-acetylcysteine plus intravenous fluids versus intravenous fluids alone to prevent contrast-induced nephropathy in emergency computed tomography

STUDY OBJECTIVE

We test the hypothesis that N-acetylcysteine plus normal saline solution is more effective than normal saline solution alone in the prevention of contrast-induced nephropathy.

METHODS

The design was a randomized, double blind, 2-center, placebo-controlled interventional trial. Inclusion criteria were patients undergoing chest, abdominal, or pelvic computed tomography (CT) scan with intravenous contrast, older than 18 years, and at least one contrast-induced nephropathy risk factor. Exclusion criteria were end-stage renal disease, pregnancy, N-acetylcysteine allergy, or clinical instability. Intervention for the treatment group was N-acetylcysteine 3 g in 500 mL normal saline solution as an intravenous bolus and then 200 mg/hour (67 mL/hour) for up to 24 hours; and for the placebo group was 500 mL normal saline solution and then 67 mL/hour for up to 24 hours. The primary outcome was contrast-induced nephropathy, defined as an increase in creatinine level of 25% or 0.5 mg/dL, measured 48 to 72 hours after CT.

RESULTS

The data safety and monitoring board terminated the study early for futility. Of 399 patients enrolled, 357 (89%) completed follow-up and were included. The N-acetylcysteine plus saline solution group contrast-induced nephropathy rate was 14 of 185 (7.6%) versus 12 of 172 (7.0%) in the normal saline solution only group (absolute risk difference 0.6%; 95% confidence interval -4.8% to 6.0%). The contrast-induced nephropathy rate in patients receiving less than 1 L intravenous fluids in the emergency department (ED) was 19 of 147 (12.9%) versus 7 of 210 (3.3%) for greater than 1 L intravenous fluids (difference 9.6%; 95% confidence interval 3.7% to 15.5%), a 69% risk reduction (odds ratio 0.41; 95% confidence interval 0.21 to 0.80) per liter of intravenous fluids.

CONCLUSION

We did not find evidence of a benefit for N-acetylcysteine administration to our ED patients undergoing contrast-enhanced CT. However, we did find a significant association between volume of intravenous fluids administered and reduction in contrast-induced nephropathy.

Incidence of contrast-induced nephropathy after contrast-enhanced computed tomography in the outpatient setting

BACKGROUND AND OBJECTIVES

No prospective study has reported the incidence of contrast-induced nephropathy (CIN) or the associated morbidity and mortality after contrast-enhanced computed tomography (CECT) in the outpatient setting.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We enrolled and followed a prospective, consecutive cohort (June 2007 through January 2009) of patients who received intravenous contrast for CECT in the emergency department of a large, academic, tertiary care center. Outcomes measured were as follows (1) CIN: An increase in serum creatinine > or =0.5 mg/dl or > or =25% 2 to 7 d after contrast administration; (2) severe renal failure: An increase in serum creatinine to > or =3.0 mg/dl or the need for dialysis at 45 d; and (3) renal failure as a contributing cause of death (consensus of three independent physicians) at 45 d.

RESULTS

The incidence of CIN was 11% (70 of 633) among the 633 patients enrolled. Fifteen (2%) patients died within 45 d, including six deaths after study-defined CIN. Seven (1%) patients developed severe renal failure, six of whom had study-defined CIN. Of the six patients with CIN and severe renal failure, four died, and adjudicators determined that renal failure significantly contributed to all four deaths. Thus, CIN was associated with an increased risk for severe renal failure and death from renal failure.

CONCLUSIONS

CIN occurs in >10% of patients who undergo CECT in the outpatient setting and is associated with a significant risk for severe renal failure and death.