Prevalence and outcome of contrast-induced nephropathy in major trauma patients

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.

Avoiding immediate whole-body trauma CT: a prospective observational study in stable trauma patients

High energy blunt trauma patients with normal vital signs are usually investigated with a Contrast Enhanced Computed Tomography (CECT) for torso injuries. CECT involves high levels of radiations, often showing no injuries in patients over-triaged to the trauma center. The aim of our study was to suggest an alternative diagnostic protocol based on Emergency Room (ER) tests (physical exam, blood tests, extended FAST, Chest and Pelvis X-ray) to avoid CECT in selected patients. A prospective cohort study was conducted from September 2018 to September 2019. Five hundred patients fulfilled the inclusion criteria. Patients received torso-CECT scan only if they had at least one positive ER test. The validity of the single component of the protocol and the global validity of the ER tests to detect torso injuries was assessed through sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, positive (+ LR) and negative (- LR) likelihood ratio. Multivariate analysis was performed to identify independent predictors of torso injuries. One hundred and seventy patients received a torso-CECT scan because of positive ER tests. ER tests showed a global sensitivity for torso injuries of 86.96% (95% CI 80.17-92.08) specificity of 83.98%(95% CI 79.79-87.60), PPV of 67.42% (95% CI 61.83-72.54), NPV of 94.41% (95% CI 91.63-96.30) + LR of 5.43 (95% CI 4.25-6.93), - LR of 0.16 (95% CI 0.10-0.24). ER tests in an experienced center seem to be able to identify more severe blunt trauma patients needing CECT. Further studies are advisable to confirm these results.