N-acetylcysteine for radiocontrast-induced nephropathy: Potential role in the emergency department?

Emergency CT Scans: Unveiling the Risks of Contrast-Associated Acute Kidney Injury

OBJECTIVES

This study aimed to identify the incidence and risk factors for contrast-associated acute kidney injury nephropathy (CA-AKI) in patients undergoing contrast-enhanced computed tomography (CCT) in the emergency department.

MATERIALS AND METHODS

In this retrospective single-center study, patients aged 18 and older who visited the emergency department and underwent CCT between January and February 2022 were included. The Mehran score, calculated from patient data, was used to assess risk. CA-AKI development was determined by measuring serum creatinine (SCr) levels 48-72 h post-contrast administration.

RESULTS

The study included 532 patients, with a mean age of 57 ± 19 years; 53.2% were male. CA-AKI developed in 16% of cases, 5.82% required hemodialysis, and 7.9% died. The Mehran score was the only significant predictor of CA-AKI development. Patients with a Mehran score of 16 or higher had a 161-fold increased risk of developing CA-AKI compared to those with a score of 5 or lower. The model achieved a 91.3% correct classification rate. Logistic regression analysis showed that CA-AKI significantly increased mortality risk by 15.7 times.

CONCLUSION

The Mehran score, originally developed for predicting CA-AKI risk post-coronary intervention, is also effective for predicting CA-AKI risk after CCT. While CA-AKI is a significant factor affecting mortality, it is not the sole cause of death (Nagelkerke R2 value 0.310).

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.