Aseptic meningitis after intraventricular administration of gentamicin

Central Nervous System Infections in the Critically Ill

Central nervous system (CNS) infections are frequently encountered in the intensive care unit setting and are a significant source of morbidity and mortality. The constantly changing trends in microbial resistance, as well as the pharmacokinetic difficulties in providing effective concentrations of antimicrobials at the site of infection represent a unique challenge to clinicians. Achievement of a successful outcome in patientswith CNS infections is reliant on eradication of the offending pathogen and management of any neurologic complications. This requires an anatomic and physiologic understanding of the different types of CNS infection, diagnostic strategies, associated complications, causative organisms, and the principles that govern drug distribution into the CNS. This article serves as a review of the epidemiology, pathophysiology, diagnosis, and treatment options for a variety of CNS infections, with a focus on those commonly encountered in an intensive care setting.

Adjunctive intraventricular antibiotic therapy for bacterial central nervous system infections in critically ill patients with traumatic brain injury

BACKGROUND

Limited data exist on the role of adjunctive intraventricular (IVT) antibiotics for the treatment of central nervous system (CNS) infections in traumatic brain injury (TBI) patients.

OBJECTIVE

To evaluate differences in CNS infection cure rates for TBI patients who received adjunctive IVT antibiotics compared with intravenous (IV) antibiotics alone.

METHODS

We retrospectively identified patients with TBI and bacterial CNS infections admitted to the trauma intensive care unit (ICU) from 1997 to 2013. Study patients received IV and IVT antibiotics, and control patients received IV antibiotics alone. Clinical and microbiological cure rates were determined from patient records, in addition to ICU and hospital lengths of stay (LOSs), ventilator days, and hospital mortality.

RESULTS

A total of 83 patients were enrolled (32 study and 51 control). The duration of IV antibiotics was similar in both groups (10 vs 12 days, P = 0.14), and the study group received IVT antibiotics for a median of 9 days. Microbiological cure rates were 84% and 82% in study and control groups, respectively (P = 0.95). Clinical cure rates were similar at all time points. No significant differences were seen in days of mechanical ventilation, ICU or hospital LOS, or hospital mortality. When only patients with external ventricular drains were compared, cure rates remained similar between groups.

CONCLUSIONS

TBI patients with CNS infections had similar microbiological and clinical cure rates whether they were treated with adjunctive IVT antibiotics or IV antibiotics alone. Shorter than recommended durations of antibiotic therapy still resulted in acceptable cure rates and similar clinically relevant outcomes.

Headache attributed to non-vascular intracranial disorder

This chapter deals with non-vascular intracranial disorders resulting in headache. Headache attributed to high or low cerebrospinal fluid pressure is separated into headache attributed to idiopathic intracranial hypertension (IIH), headache attributed to intracranial hypertension secondary to metabolic, toxic, or hormonal causes, headache attributed to intracranial hypertension secondary to hydrocephalus, post-dural puncture headache, cerebrospinal fluid (CSF) fistula headache, headache attributed to spontaneous (or idiopathic) low CSF pressure. Headache attributed to non-infectious inflammatory disease can be caused by neurosarcoidosis, aseptic (non-infectious) meningitis or lymphocytic hypophysitis. Headache attributed to intracranial neoplasm can be caused by increased intracranial pressure or hydrocephalus caused by neoplasm or attributed directly to neoplasm or carcinomatous meningitis. Other causes of headache include hypothalamic or pituitary hyper- or hyposecretion and intrathecal injection. Headache attributed to epileptic seizure is separated into hemicrania epileptica and post-seizure headache. Finally headache attributed to Chiari malformation type I (CM1) and the syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) are described.

Improving the role of intraventricular antimicrobial agents in the management of meningitis

PURPOSE OF REVIEW

The aim is to review the role of intraventricular administration of antimicrobial agents in the treatment of patients with bacterial and fungal meningitis.

RECENT FINDINGS

This article discusses indications for intraventricular antimicrobial agents, choice of antibiotics, strategies to monitor pharmacokinetics of central nervous system compartments and unanswered issues for this management approach.

SUMMARY

Intraventricular administration of antimicrobials may be necessary in certain difficult- to- eradicate central nervous system infections. There is a significant need for clinical trials and management guidelines in this area.

Update in the diagnosis and management of central nervous system infections

Central nervous system (CNS) infections presenting to the emergency room include meningitis, encephalitis, brain and spinal epidural abscess, subdural empyema, and ventriculitis. These conditions often require admission to an intensive care unit (ICU) and are complications of ICU patients with neurologic injury, contributing significantly to morbidity and mortality. Reducing morbidity and mortality is critically dependent on rapid diagnosis and, perhaps more importantly, on the timely initiation of appropriate antimicrobial therapy. New insights into the role of inflammation and the immune response in CNS infections have contributed to development of new diagnostic strategies using markers of inflammation, and to the study of agents with focused immunomodulatory activity, which may lead to further adjunctive therapy in human disease.

Advances in the management of central nervous system infections in the ICU

This chapter focuses on early aggressive management of common infections of the central nervous system that require monitoring in an ICU setting. These include meningitis, encephalitis, brain and epidural abscess, subdural empyema and ventriculitis. It emphasizes priorities in evaluation and management due to increasing morbidity and mortality as a result of failure to appreciate non-specific symptoms or administer timely therapy. The emergence of organisms resistant to penicillin and cephalosporins has also further complicated the early management of bacterial meningitis. Current antimicrobial guidelines are provided along with discussion of new diagnostic and therapeutic strategies and controversial aspects of management.

A retrospective study of central nervous system shunt infections diagnosed in a university hospital during a 4-year period

BACKGROUND

Ventriculoperitoneal (VP) shunts are used for intracranial pressure management and temporary cerebrospinal fluid (CSF) drainage. Infection of the central nervous system (CNS) is a major cause of morbidity and mortality in patients with CSF shunts. The aim of the present study was to evaluate the clinical features, pathogens, and outcomes of 22 patients with CSF shunt infections collected over 4 years.

METHODS

The patients with shunt insertions were evaluated using; age, sex, etiology of hydrocephalus, shunt infection numbers, biochemical and microbiological parameters, prognosis, clinical infection features and clinical outcome.

RESULTS

The most common causes of the etiology of hydrocephalus in shunt infected patients were congenital hydrocephalus-myelomeningocele (32%) and meningitis (23%). The commonest causative microorganism identified was Staphylococcus (S.) aureus, followed by Acinetobacter spp., and S. epidermidis.

CONCLUSION

In a case of a shunt infection the timely usage of appropriate antibiotics, according to the antimicrobial susceptibility testing, and the removal of the shunt apparatus is essential for successful treatment.

Acute Bacterial Meningitis in Children

Despite advances in recent decades in management, including new and effective antimicrobials, children with bacterial meningitis still incur significant morbidity and mortality. Pathophysiologic processes including colonization and migration of the bacteria to blood, seeding of the meninges, and meningeal and brain inflammation have been largely elucidated, but more specific knowledge could lead to new effective therapies. Outside of the neonatal period, the most common causative organisms have been Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis. However, conjugate vaccines, especially the H influenzae type b preparation, have contributed significantly to steep declines in the incidence of meningitis. Optimal management consists of rapid diagnosis and administration of bactericidal antibiotics with properties allowing adequate penetration of the inflamed blood-brain barrier. Recently, development of microbial resistance has resulted in changes to recommended empiric antibiotic regimens. Novel therapies are under investigation; however, until controlled trials can be conducted, these therapies cannot be recommended.