Cefepime is Associated with Acute Encephalopathy in Critically Ill Patients: A Retrospective Case-Control Study

Research progress in the pathogenesis of sepsis-associated encephalopathy

Sepsis is a syndrome that causes dysfunction of multiple organs due to the host's uncontrolled response to infection and is a significant contributor to morbidity and mortality in intensive care units worldwide. Surviving patients are often left with acute brain injury and long-term cognitive impairment, known as sepsis-associated encephalopathy (SAE). In recent years, researchers have directed their focus towards the pathogenesis of SAE. However, due to the complexity of its development, there remains a lack of effective treatment measures that arise as a serious issue affecting the prognosis of sepsis patients. Further research on the possible causes of SAE aims to provide clinicians with potential therapeutic targets and help develop targeted prevention strategies. This paper aims to review recent research on the pathogenesis of SAE, in order to enhance our understanding of this syndrome.

Danger in plain sight: determining who is at highest risk for cefepime induced neurotoxicity and its associated morbidity and mortality

Cefepime is a fourth-generation cephalosporin that is widely used to treat sepsis but is associated with a potentially dangerous neurotoxicity syndrome, cefepime-induced neurotoxicity (CIN). As a result, patients treated with cefepime may be at higher risk for morbidity, including seizures, and mortality. Though the recent ACORN trial concluded that cefepime does not increase the risk of mortality, most of these patients were not critically ill or elderly, two of the most at risk populations for CIN. Further, diagnosis may be difficult in the critical care setting as patients may have multiple reasons for encephalopathy. Therefore, this population in particular should be studied and monitored closely for CIN. Importantly, there are not well defined diagnostic criteria for CIN to guide evaluation and management. Defining the risk factors for CIN and using laboratory and EEG to help support the clinical diagnosis could be helpful in early recognition of CIN to help institute treatment and to rule out seizures. In this mini review, we highlight risk factors for CIN, discuss the possible value of EEG, and propose a diagnostic and management approach in the evaluation and management of CIN.

The spectrum of sepsis-associated encephalopathy: a clinical perspective

Sepsis-associated encephalopathy is a severe neurologic syndrome characterized by a diffuse dysfunction of the brain caused by sepsis. This review provides a concise overview of diagnostic tools and management strategies for SAE at the acute phase and in the long term. Early recognition and diagnosis of SAE are crucial for effective management. Because neurologic evaluation can be confounded by several factors in the intensive care unit setting, a multimodal approach is warranted for diagnosis and management. Diagnostic tools commonly employed include clinical evaluation, metabolic tests, electroencephalography, and neuroimaging in selected cases. The usefulness of blood biomarkers of brain injury for diagnosis remains limited. Clinical evaluation involves assessing the patient's mental status, motor responses, brainstem reflexes, and presence of abnormal movements. Electroencephalography can rule out non-convulsive seizures and help detect several patterns of various severity such as generalized slowing, epileptiform discharges, and triphasic waves. In patients with acute encephalopathy, the diagnostic value of non-contrast computed tomography is limited. In septic patients with persistent encephalopathy, seizures, and/or focal signs, magnetic resonance imaging detects brain injury in more than 50% of cases, mainly cerebrovascular complications, and white matter changes. Timely identification and treatment of the underlying infection are paramount, along with effective control of systemic factors that may contribute to secondary brain injury. Upon admission to the ICU, maintaining appropriate levels of oxygenation, blood pressure, and metabolic balance is crucial. Throughout the ICU stay, it is important to be mindful of the potential neurotoxic effects associated with specific medications like midazolam and cefepime, and to closely monitor patients for non-convulsive seizures. The potential efficacy of targeted neurocritical care during the acute phase in optimizing patient outcomes deserves to be further investigated. Sepsis-associated encephalopathy may lead to permanent neurologic sequelae. Seizures occurring in the acute phase increase the susceptibility to long-term epilepsy. Extended ICU stays and the presence of sepsis-associated encephalopathy are linked to functional disability and neuropsychological sequelae, underscoring the necessity for long-term surveillance in the comprehensive care of septic patients.

Continuous Infusion of High Doses of Cefepime in Intensive Care Unit: Assessment of Steady-State Plasma Level and Incidence on Neurotoxicity

Continuous infusion (CI) with high doses of cefepime is recommended in the empirical antimicrobial regimen of critically ill patients with suspected Gram-negative sepsis. This study aimed to determine factors associated with cefepime overdosing and the incidence of cefepime-induced neurotoxicity (CIN) in these patients. We performed a retrospective study including all patients receiving cefepime treatment between January 2019 and May 2022. The plasma level of cefepime defining overdosing was over 35 mg/L. Neurotoxicity was defined according to strict criteria and correlated with concomitant steady-state concentration of cefepime. Seventy-eight courses of cefepime treatment were analyzed. The mean cefepime plasma level at steady state was 59.8 ± 29.3 mg/L, and overdosing occurred in 80% of patients. Renal failure and a daily dose > 5 g were independently associated with overdosing. CIN was present in 30% of patients. In multivariate analysis, factors associated with CIN were chronic renal failure and a cefepime plasma concentration ≥ 60 mg/L. CIN was not associated with mortality. Overdosing is frequent in patients receiving high doses of cefepime by CI. Steady-state levels are higher than targeted therapeutic pharmacokinetic/pharmacodynamic objectives. The risk of CIN is important when the plasma concentration is ≥60 mg/L.

Progression of Kidney Injury with the Combination of Vancomycin and Piperacillin-Tazobactam or Cefepime in Sepsis-Associated Acute Kidney Injury

INTRODUCTION

The combination of vancomycin/piperacillin-tazobactam is associated with increases in serum creatinine compared to other antibiotic combinations in the treatment of infections for hospitalized patients. However, the available literature is limited to the study of incident acute kidney injury (AKI). The combination has not been evaluated in patients with AKI already present and the degree to which the trajectory of AKI is influenced by this combination is unknown.

METHODS

This was a single center, retrospective cohort study of adult patients with sepsis and AKI present on admission prescribed a combination of vancomycin with either piperacillin-tazobactam or cefepime within the first 3 days of admission. The primary outcome was maximum serum creatinine observed within days 2-7 of the hospital stay. Subsequent kidney outcomes were evaluated at one week and hospital discharge.

RESULTS

Of 480 patients with sepsis and AKI who met inclusion criteria, 288 (60%) received vancomycin/piperacillin-tazobactam, and 192 (40%) received vancomycin/cefepime. Patients were well-matched on clinical factors, including severity of illness, stage of AKI, exposure to other nephrotoxins, and durations of antimicrobial therapy. There were no differences in AKI trajectory during the first week as assessed by maximum serum creatinine (2.1 (1.4-3.5) mg/dl vs. 2.1 (1.4-3.0) mg/dl; p=0.459) and AKI progression (24.0% vs. 23.4%; p=0.895). No differences were observed with other kidney related outcomes, including the need for dialysis (14.6% vs. 13.0%; p=0.628) or major adverse kidney events at hospital discharge (48.3% vs. 47.9%; p=0.941).

CONCLUSIONS

In patients with sepsis and AKI, the combination of vancomycin/piperacillin-tazobactam compared to vancomycin/cefepime was not associated with higher serum creatinine values or AKI progression in the week following ICU admission.

EEG background frequency is associated with discharge outcomes in non-ICU hospitalized patients with COVID-19

Objective

To assess risk factors for encephalopathy in non-ICU hospitalized patients with COVID-19 and the effect of encephalopathy on short-term outcomes.

Methods

We collected clinical and electrophysiological characteristics of fifty patients with COVID-19 infection admitted to a ward service and who had an electroencephalogram (EEG) performed. Associations with short-term outcomes including hospital length of stay and discharge disposition were determined from univariate and multivariate statistical analysis.

Results

Clinical delirium was associated with encephalopathy on EEG, cefepime use was associated with increased length of stay, and of all factors analyzed, background frequency on EEG alone was correlated with discharge disposition.

Conclusion

Encephalopathy is one of the major determinants of short-term outcomes in hospitalized non-ICU patients with COVID-19.

Cefepime-induced neurotoxicity: systematic review

BACKGROUND

Cefepime-induced neurotoxicity (CIN) has been well acknowledged among clinicians, although there are no clear diagnostic criteria or specific laboratory testing to help with its diagnosis. We aimed to summarize the existing evidence regarding CIN and provide future agendas for research.

METHODS

Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and Embase for all peer-reviewed articles using keywords including 'cefepime', 'neurotoxicity', 'encephalopathy' and 'seizure', from their inception to 20 January 2022.

RESULTS

We included 92 articles, including 23 observational studies and 69 cases from case reports and case series, in the systematic review. Among 119 patients with CIN, 23.5% were in the ICU at the time of diagnosis and nearly 90% of the cases showed renal dysfunction.Cefepime overdoses were described in 41%. The median latency period of developing CIN from cefepime initiation was 4 days, and about 12% developed CIN during empirical treatment. CIN patients commonly manifested altered mental status (93%), myoclonus (37%) and non-convulsive seizure epilepticus (28%). A serum cefepime trough level of >20 mg/L would put patients at risk for CIN. CIN-related symptoms were ameliorated in 97.5% by dose reduction or discontinuation of cefepime, with median time to improvement of 3 days. No CIN-associated deaths were reported.

CONCLUSIONS

This systematic review summarizes the current evidence and characteristics of CIN. In the current situation where there are no CIN diagnostic criteria and the drug monitoring platform is not routinely available, candidates for cefepime should be carefully selected. Also, based on these findings, it needs to be appropriately dosed to avoid the development of CIN.

Analysis of the frequency of ceftriaxone-induced encephalopathy using the Japanese Adverse Drug Event Report database

BACKGROUND

The profile of ceftriaxone-induced encephalopathy is not well understood.

AIM

To identify risk factors associated with ceftriaxone-induced encephalopathy.

METHOD

In this observational study, anonymised patient data were retrieved from the open-access Japanese Adverse Drug Event Report database for ceftriaxone users aged 20 years or higher.

RESULTS

Data of 256,788 individuals and 12,160 cases of encephalopathy were extracted, and 2,939 ceftriaxone users, of whom 193 had encephalopathy, were identified. A disproportionate prevalence of encephalopathy was observed among the ceftriaxone users (reported odds ratio = 1.42; 95% confidence interval [CI] = 1.23-1.65; p < 0.001). Multivariate logistic regression analysis of 2,057 ceftriaxone users showed encephalopathy was associated with female sex (odds ratio [OR] = 1.52; 95% CI, 1.05-2.19; p = 0.027), chronic kidney disease (OR = 2.32; 95% CI, 1.47-3.67; p < 0.001), a ceftriaxone dosage of > 2 g/day (OR = 2.66; 95% CI, 1.66-4.26; p < 0.001), and a treatment duration of > 14 days (OR = 1.94; 95% CI, 1.21-3.11; p = 0.006).

CONCLUSION

Patients with chronic kidney disease, receiving ceftriaxone at a dosage of > 2 g/day, being treated for over 14 days, and/or females may be at an increased risk of ceftriaxone-induced encephalopathy.

Clinical Pharmacokinetics and Pharmacodynamics of Cefepime

Cefepime is a broad-spectrum fourth-generation cephalosporin with activity against Gram-positive and Gram-negative pathogens. It is generally administered as an infusion over 30-60 min or as a prolonged infusion with infusion times from 3 h to continuous administration. Cefepime is widely distributed in biological fluids and tissues with an average volume of distribution of ~ 0.2 L/kg in healthy adults with normal renal function. Protein binding is relatively low (20%), and elimination is mainly renal. About 85% of the dose is excreted unchanged in the urine, with an elimination half-life of 2-2.3 h. The pharmacokinetics of cefepime is altered under certain pathophysiological conditions, resulting in high inter-individual variability in cefepime volume of distribution and clearance, which poses challenges for population dosing approaches. Consequently, therapeutic drug monitoring of cefepime may be beneficial in certain patients including those who are critically ill, have life-threatening infections, or are infected with more resistant pathogens. Cefepime is generally safe and efficacious, with a goal exposure target of 70% time of the free drug concentration over the minimum inhibitory concentration for clinical efficacy. In recent years, reports of neurotoxicity have increased, specifically in patients with impaired renal function. This review summarizes the pharmacokinetics, pharmacodynamics, and toxicodynamics of cefepime contemporarily in the setting of increasing cefepime exposures. We explore the potential benefits of extended or continuous infusions and therapeutic drug monitoring in special populations.

Incidence and Predictive Factors Associated with Beta-Lactam Neurotoxicity in the Critically Ill: A Retrospective Cohort Study

BACKGROUND

Beta-lactam neurotoxicity is a relatively uncommon yet clinically significant adverse effect in critically ill patients. This study sought to define the incidence of neurotoxicity, derive a prediction model for beta-lactam neurotoxicity, and then validate the model in an independent cohort of critically ill adults.

METHODS

This retrospective cohort study evaluated critically ill patients treated with ≥ 48 h of cefepime, piperacillin/tazobactam, or meropenem. Two separate cohorts were created: a derivation cohort and a validation cohort. Patients were screened for beta-lactam neurotoxicity by using search terms and diagnosis codes, followed by clinical adjudication using a standardized adverse event scoring tool. Multivariable regression models and least absolute shrinkage and selection operator were used to identify surrogates for neurotoxicity and develop a multivariable prediction model.

RESULTS

The overall incidence of beta-lactam neurotoxicity was 2.6% (n/N = 34/1323) in the derivation cohort and 2.1% in the validation cohort (n/N = 16/767). The final multivariable neurotoxicity assessment tool included weight, Charlson comorbidity score, age, and estimated creatinine clearance as predictors of neurotoxicity. Incidence of neurotoxicity reached 4% in those with a body mass index more than 30 kg/m². Use of the candidate variables in the neurotoxicity assessment tool suggested that a score more than 35 would identify a patient at high risk for neurotoxicity with 75% sensitivity and 54% specificity.

CONCLUSIONS

In this single center cohort of critically ill patients, beta-lactam neurotoxicity was demonstrated less frequently than previously reported. We identified obesity as a novel risk factor for the development of neurotoxicity. The prediction model needs to be further refined before it can be used in clinical practice as a tool to avoid drug-related harm.

Delirium Associations with Antibiotics: A Pharmacovigilance Study of the FDA Adverse Event Reporting System (FAERS)

Background

Ertapenem, cefepime, imipenem, ofloxacin, ceftazidime, clarithromycin, cefaclor, levofloxacin, linezolid, moxifloxacin, azithromycin, piperacillin–tazobactam, trimethoprim–sulfamethoxazole, metronidazole, ciprofloxacin, and cefuroxime are known to be associated with delirium. Other antibiotics may also lead to delirium, but no study has systemically compared delirium associations for many available antibiotics.

Objective

The objective of this study was to evaluate the association between delirium and antibiotics using the FDA Adverse Event Reporting System (FAERS).

Methods

FAERS reports from January 1, 2004 to December 31, 2018 were included in the study. Reporting odds ratios (RORs) and corresponding 95% confidence intervals (95% CI) for the association between antibiotics and delirium were calculated. An association was considered to be statistically significant when the lower limit of the 95% CI was greater than 1.0.

Results

A total of 10,015,622 reports (including 16,982 delirium reports) were considered, after inclusion criteria were applied. Statistically significant delirium RORs (95% CI) for antibiotics were: ertapenem 21.07 (16.38–27.10), cefepime 9.8 (6.37–15.09), imipenem 9.68 (6.75–13.89), ofloxacin 7.73 (4.00–14.92), ceftazidime 6.09 (2.73–13.62), clarithromycin 5.34 (4.37–6.53), cefaclor 5.32 (1.71–16.58), ampicillin–sulbactam 4.49 (2.13–9.45), levofloxacin 4.47 (3.88–5.16), linezolid 4.33 (3.28–5.72), moxifloxacin 3.51 (2.81–4.38), azithromycin 2.76 (2.09–3.64), piperacillin–tazobactam 2.41 (1.47–3.93), trimethoprim–sulfamethoxazole 2.36 (1.61–3.47), metronidazole 1.85 (1.31–2.60), ciprofloxacin 1.83 (1.44–2.33), and cefuroxime 1.81 (1.03–3.20).

Conclusion

This study found statistically significant increased risk of reporting delirium with ertapenem, cefepime, imipenem, ofloxacin, ceftazidime, clarithromycin, cefaclor, ampicillin–sulbactam, levofloxacin, linezolid, moxifloxacin, azithromycin, piperacillin–tazobactam, trimethoprim–sulfamethoxazole, metronidazole, ciprofloxacin, and cefuroxime.

Acute Coma

An acutely comatose patient constitutes a medical emergency until proved otherwise. Managing these emergencies requires organized teamwork to recognize and treat life-threatening situations and reversible causes of coma. Once vital functions have been stabilized, information from the history and physical examination should be used to rationally guide subsequent testing. Identifying causes of coma for which emergency treatment is possible should be the priority. The treatment and prognosis depend on the cause.

Cefepime-Induced Encephalopathy With Seizures in a Pediatric Patient With End-Stage Renal Disease Rapidly Reversed by High-Efficiency Hemodialysis

Cefepime-induced encephalopathy with associated complications is a relatively rare but known adverse reaction that appears to occur more commonly in the elderly population with concomitant renal dysfunction or pre-existing central nervous system disease. The description of neurological features in pediatric patients secondary to cefepime-induced encephalopathy has rarely been reported, often delaying diagnosis and treatment. We report a 13-year-old female with end-stage renal disease, maintained on hemodialysis, who developed acute neurological symptoms of aphasia, myoclonus, hallucinations, seizures, and altered mental status after two days of cefepime treatment. After prompt discontinuation of cefepime and urgent hemodialysis, the neurological symptoms were resolved. Our patient had complete neurological recovery within 24 hours of the initial presentation of neurological symptoms. Recognizing the possibility of encephalopathy related to cefepime administration in high-risk pediatric patients should prompt close neurological monitoring when under treatment. Hemodialysis may help rapidly reverse the symptoms of cefepime-induced encephalopathy.