Ceftazidime-related neurotoxicity in a patient with renal impairment: a case report and literature review

PURPOSE

We present the case of a 67-year-old woman with severely reduced renal clearance suffering from ceftazidime-induced encephalopathy. Subsequently, we search the literature to review and describe the neurotoxicity of ceftazidime.

METHODS

A search string was developed to search PubMed for relevant cases from which relevant information was extracted. Using the collected data a ROC analysis was performed in R to determine a neurotoxicity threshold.

RESULTS

Our patient suffered from progressive loss of consciousness and myoclonic seizures, with improvements noted a few days after discontinuation of treatment. The dose was not appropriately reduced to take into account her reduced renal function. The highest ceftazidime concentration recorded was 234.9 mg/mL. Using the Naranjo score we found a probable relationship between our patient's encephalopathy and ceftazidime administration. In the literature we found a total of 32 similar cases, most of which also had some form of renal impairment. Using our collected data and ceftazidime concentrations provided in the literature, a ROC analysis provided a neurotoxicity threshold of 78 mg/L for ceftazidime neurotoxicity.

CONCLUSION

Ceftazidime-related neurotoxicity is a known issue, especially in patients with severe renal impairment. Yet no concrete toxicity threshold has been reported so far. We propose the first toxicity threshold for ceftazidime of 78 mg/L. Future prospective studies are needed to validate and optimize the neurotoxicity threshold as upper limit for ceftazidime therapeutic drug monitoring.

Characterization of the internal working-life exposome using minimally and non-invasive sampling methods - a narrative review

During recent years, we are moving away from the 'one exposure, one disease'-approach in occupational settings and towards a more comprehensive approach, taking into account the totality of exposures during a life course by using an exposome approach. Taking an exposome approach however is accompanied by many challenges, one of which, for example, relates to the collection of biological samples. Methods used for sample collection in occupational exposome studies should ideally be minimally invasive, while at the same time sensitive, and enable meaningful repeated sampling in a large population and over a longer time period. This might be hampered in specific situations e.g., people working in remote areas, during pandemics or with flexible work hours. In these situations, using self-sampling techniques might offer a solution. Therefore, our aim was to identify existing self-sampling techniques and to evaluate the applicability of these techniques in an occupational exposome context by conducting a literature review. We here present an overview of current self-sampling methodologies used to characterize the internal exposome. In addition, the use of different biological matrices was evaluated and subdivided based on their level of invasiveness and applicability in an occupational exposome context. In conclusion, this review and the overview of self-sampling techniques presented herein can serve as a guide in the design of future (occupational) exposome studies while circumventing sample collection challenges associated with exposome studies.

Systematic review of genotoxicity induced by occupational exposure to antineoplastic drugs

With increasing numbers of cancer cases, the use of antineoplastic agents is expected to rise. This will be accompanied by an increase in occupational exposure, which can cause unwanted health effects in workers. Our aim was to give an overview of genotoxic and epigenetic effects after occupational exposure to antineoplastic agents and to assess the concentration-effect relation. Four databases were searched for papers investigating genotoxic and/or epigenetic effects of occupational exposure to antineoplastic agents. Out of the 245 retrieved papers, 62 were included in this review. In this systematic literature review, we confirmed that exposure of healthcare workers to antineoplastic agents can lead to genotoxic damage. However, we observed a lack of data on exposure as well as genotoxic and epigenetic effects in workers other than healthcare workers. Furthermore, gaps in the current knowledge regarding the potential epigenetic effects caused by antineoplastic drug exposure and regarding the link between internal antineoplastic drug concentration and genotoxic and epigenetic effects after occupational exposure to antineoplastic agents were identified, offering a first step for future research.

Quantification of three antineoplastic agents in urine using the UniSpray ionisation source

BACKGROUND

Many guidelines and safety measures led to a decrease in exposure to antineoplastic agents. Since healthcare workers are often exposed to lower concentrations than patients, a sensitive method is needed to quantify occupational exposure.

OBJECTIVE

The aim of this study was to develop and validate a sensitive method for simultaneous detection and quantification of cyclophosphamide, ifosfamide and paclitaxel in urine by use of UPLC-MS/MS with a UniSpray ionisation source.

METHODS

Compounds were extracted from urine using Novum simplified liquid extraction cartridges, separated on a C18 column, ionised by a UniSpray ionisation source and detected with MS/MS. In the second part of the study, a field study was performed to assess occupational exposure to antineoplastic agents.

RESULTS

Eighty-three samples from healthcare workers were analysed and resulted in seventeen samples containing quantifiable concentrations of at least one compound. In conclusion, a sensitive method for simultaneous detection and quantification of cyclophosphamide (LLOQ 0.05 ng/mL), ifosfamide (LLOQ 0.3 ng/mL) and paclitaxel (LLOQ 0.7 ng/mL) was developed and validated.

CT density measurement and H:H ratio are useful in diagnosing acute cerebral venous sinus thrombosis

BACKGROUND AND PURPOSE

Brain CT is widely used to exclude or confirm acute cerebral venous sinus thrombosis. The purpose of this study was to assess the value of attenuation measurement and the H:H ratio on unenhanced brain CT scans in the diagnosis of acute cerebral venous sinus thrombosis.

MATERIALS AND METHODS

This retrospective study evaluated 20 patients with acute cerebral venous sinus thrombosis and 20 age- and sex-matched control participants without thrombosis. Three experienced observers independently evaluated the unenhanced brain CT scan for the presence of cerebral venous sinus thrombosis and measured the attenuation in the dural sinuses. Interreader differences were examined, as well as densities and H:H ratio between patients with acute cerebral venous sinus thrombosis and control participants.

RESULTS

A significant difference in the average sinus attenuation was found between patients with acute cerebral venous sinus thrombosis (73.9 ± 9.2 HU) and the control group (52.8 ± 6.7 HU; P < .0001). A similar difference was found for the H:H ratio (1.91 ± 0.32 vs 1.33 ± 0.12 in patients with and without cerebral venous sinus thrombosis, respectively; P < .0001). Optimal thresholds of 62 HU and 1.52 lead to accuracies of 95% for average sinus attenuation and 97.5% for the H:H ratio, respectively.

CONCLUSIONS

Hyperattenuation and the H:H ratio in the dural sinuses on unenhanced brain CT scans have a high accuracy in the detection of acute cerebral venous sinus thrombosis.

Hypoplasia of L5 and wedging and pseudospondylolisthesis in patients with spondylolysis: study with MR imaging

BACKGROUND AND PURPOSE

The association between L5 hypoplasia and bilateral spondylolysis was described earlier on conventional radiographs of the lumbar spine. The purpose of this study was to describe the findings on MR imaging in patients with hypoplasia of L5 and to correlate these findings with the presence of bilateral spondylolysis of L5.

MATERIAL AND METHODS

We studied the MR images of 22 patients with hypoplasia and posterior wedging of L5 and with bilateral spondylolysis at L5. The anteroposterior diameter of L4, L5, and S1 were measured and compared. The degree of posterior wedging of L5 was calculated. The degree of anterolisthesis was determined. The intervertebral disks of L4-L5 and L5-S1 were studied.

RESULTS

The mean difference between the anteroposterior diameter of L4 and L5 was 3.0 mm, or 8.8% shortening of L5 compared with L4. The mean difference between the anteroposterior diameter of L5 and S1 was 4.4 mm, or 12.3% shortening of L5 compared with S1. The mean percentage posterior wedging was 24.7%. In 13 patients, there was no anterior vertebral slipping. True anterolisthesis grade I was seen in 5 patients and anterolisthesis grade II in 4 patients. Diskarthrosis with disk dehydration of L4-L5 was seen in 20 of the 22 patients.

CONCLUSIONS

It is confirmed that hypoplasia of L5 can simulate anterolisthesis. Hypoplasia of the vertebral body of L5 can predict the presence of bilateral spondylolysis.

Comparative study of the density of particles in suspensions for patch testing

A simple and reliable method to evaluate the density of particles in patch test suspensions is described. The number of particles per unit volume has been found to vary significantly within a wide range of values. These variations have no relation to the concentration or the molecular weight of the substance, as far as particles larger than 10 micron are concerned. Because the presence of particles is one of the factors which can influence percutaneous penetration and since physical manipulations are able to modify the size of these particles, it is suggested that the kinetics of penetration of haptens through the skin should be revaluated with regard to this special point.