The administration of iodinated contrast media (CM) can cause microcirculatory disorder leading to acute renal dysfunction. In a prospective, randomized investigation two CM (Iodixanol vs Iopromide) were compared in 16 pigs. Each animal received 10 intra-aortal injections (5 ml Iodixanol or 4.32 ml Iopromide). Microcirculation was assessed using contrast-enhanced ultrasound (CEUS) directly on the kidney surface using time-to-peak (TTP) and blood-volume-analysis. Macroscopic observations were documented. Post mortem residual CM distribution in the kidneys was detected using X-ray. TTP was significantly prolonged over the descending vasa recta of the Iopromide group. This coincided with a visible marble-like pattern on the kidney surface occurring in 30 out of 80 Iopromide-injections but in 4 out of 80 Iodixanol-injections (p = 0.007). The blood volume over the entire kidney did not change after Iodixanol-application, but decreased by about 6.1% after Iopromide-application. The regional blood volume in the renal cortex showed a tendency to decrease by about 13.5% (p = 0.094) after Iodixanol-application, and clearly decreased by about 31.7% (p = 0.022) after Iopromide-application. The study revealed a consistent influence of repeated injections of two different CM on the kidney perfusion using three different imaging methods (CEUS analysis, macroscopic observation and X-ray analysis).

While iso-osmolar CM induced an increase of PSV and EDV together with a decrease of RRI, low-osmolar CM could not show this effect or rather led to the opposite.

Background The coronavirus pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is posing unprecedented challenges to health care systems around the globe. Consequently, various lockdown scenarios have been politically imposed to get control over the spread of this disease. We examined the impact of the lockdown situation on the number of neurosurgical emergency patients admitted to our tertiary care center with a catchment area of ∼2.2 million inhabitants in the south of Germany to ensure adequate neurosurgical emergency care during a pandemic lockdown. Methods All emergency admissions (with consecutive inpatient treatment) to the Department of Neurosurgery at the University Medical Center Regensburg, Germany, between March 1 and May 8 (69 days) of the years 2018, 2019, and 2020 were retrospectively identified and reviewed for this study. Demographic data, diagnoses, urgency of surgery, and duration of the journey to the emergency room were examined. Results Between March 1 and May 8, 2020, 59 emergency patients were neurosurgically treated at our department. Compared with 2018 and 2019, emergency admissions in 2020 had thus declined by 37.2 and 27.1%, respectively. Regarding the year 2020, we found a significant drop from 1.71 and 1.52 emergency patients per day in January and February 2020, respectively, to 0.86 during lockdown (p < 0.001). The decline especially concerned nontraumatic spinal cases and also patients with other neurosurgical diagnoses such as intracranial hemorrhage. Evaluation of the overall disease severity of admitted patients by means of the urgency of surgery showed no difference between the baseline years and the lockdown period. Conclusion Our findings are in line with other observational studies of neurosurgical, neurologic, and cardiologic centers in Europe that have described a drop in emergency cases. The reasons for this drop that seems to affect various medical fields and countries across Europe are still unidentified. Morbidity and mortality rates are still unknown, and efforts should be made to facilitate neurosurgical emergency care during a pandemic lockdown.

No abstract

Repeated injections of iodinated contrast media (CM) can lead to a deterioration of the renal blood flow, can redistribute blood from the renal cortex to other parts of the kidney and can cause small decreases of the blood flow in cortical capillaries, a significant reduction in blood flow in peritubular capillaries and a significant reduction in blood flow in the vasa recta. Therefore, a study in pigs was designed, to show whether the repeated injection of CM boli, alone, can cause a reduction of oxygenation in the cortico-medullar renal tissue -the region with the highest oxygen demand in the kidney -of pigs.While the mean pO 2 -value had only decreased by 0.3 mmHg from 29.9 ± 4.3 mmHg to 29.6 ± 4.3 mmHg (p = 0.8799) after the tenth Iodixanol bolus, it decreased by 5.9 mmHg from 34.0 ± 4.3 mmHg to 28.1 ± 4.3 mmHg after the tenth Iopromide bolus (p = 0.044). This revealed a remarkable difference in the influence of these CM on the oxygen partial pressure in the kidney.Repeated applications of CM had a significant influence on the renal oxygen partial pressure. In line with earlier studies showing a redistribution of blood from the cortex to other renal areas, this study revealed that Iodixanol -in contrast to Iopromide -induced no changes in the pO 2 in the cortico-medullar region which confirms that Iodixanol did not hinder the flow of blood through the renal micro-vessels. These results are in favor of a hypothesis from Brezis that a microcirculatory disorder might be the basis for the development of CI-AKI.