Hyponatraemia in adults with community-acquired bacterial meningitis

BACKGROUND: Hyponatraemia in adults with bacterial meningitis has been described as a common complication, but its true prevalence and clinical importance are unknown. AIM: To investigate the prevalence, clinical characteristics and consequences of hyponatraemia in bacterial meningitis in adults. DESIGN: Nationwide observational cohort study. METHODS: We prospectively assessed the prevalence and clinical characteristics of hyponatraemia among 696 adults with community-acquired bacterial meningitis. Symptoms and signs on admission, blood and CSF test results, radiological examinations and complications during admission were recorded. RESULTS: Sodium levels were determined at admission in 685/696 episodes of bacterial meningitis (98%). Hyponatraemia (<135 mmol/l) was seen in 208/685 (30%) and was classified as severe (<130 mmol/l) in 38 (6%). Hyponatraemia developed during admission in an additional 53 episodes. Hyponatraemia was not associated with an increase in symptoms, with complications or with unfavourable outcome. Treatment for hyponatraemia was initiated in 16% of episodes, but did not influence its duration. DISCUSSION: Hyponatraemia appears both common and benign in adults with bacterial meningitis. In cases of severe hyponatraemia, we suggest the use of fluid maintenance therapy.     

Cerebral haemodynamics in acute bacterial meningitis in adults

BACKGROUND: Vascular complications are an important cause of neurological sequelae among adult survivors of acute bacterial meningitis (ABM). AIM: To examine the haemodynamic changes associated with ABM. METHODS: Serial transcranial colour-coded sonography (TCCS) and magnetic resonance angiography (MRA) were used to examine cerebrovascular changes in adult ABM patients. Outcome at 3 months was categorized using a modified Barthel index. RESULTS: We recruited 24 patients, 12 men and 12 women, aged 21-68 years. Mean cerebral blood flow velocity (V(mean)) increased from day 1 to day 4 in the middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA). On day 4, V(mean) values in the MCA, ACA and PCA were all significantly higher than reference values in healthy volunteers. At 3 months follow-up, 16 cases had good outcomes, while the other eight had poor outcomes. Under multiple logistic regression analysis, only Glasgow coma score (GCS) at admission was independently associated with the three-month outcome. DISCUSSION: In these patient, stenosis as demonstrated by TCCS did not wholly coincide with stenosis as demonstrated by MRA, and the presence of intracranial stenosis was not predictive of a poor outcome at 3 months. Further studies are needed to delineate the characteristics and significance of cerebrovascular changes in adult ABM.     

Utility of prognostic stratification in adults with community-acquired bacterial meningitis

Prognostic stratification uses baseline clinical features to subdivide patients into subgroups with different risks for a particular outcome. We review the importance of prognostic stratification in internal medicine, in infectious diseases, and in adults with community-acquired bacterial meningitis.     

Acute bacterial meningitis in children and adults. A perspective

Bacterial meningitis is an acute and serious illness associated with significant morbidity and mortality. Although methods to make the diagnosis are relatively simple and effective antimicrobial agents are available, bacterial meningitis accounts for more than 2000 reported deaths per year in the United States. The majority of cases and deaths occur in otherwise healthy individuals.     

Arterial cerebrovascular complications in 94 adults with acute bacterial meningitis

Introduction  

Intracranial vascular complications are an important complication of acute bacterial meningitis. Ischemic stroke in meningitis is reported as a result of vasculitis, vasospasm, endocarditis or intraarterial thrombosis. The aim of the study was to identify the value of measuring cerebral blood flow velocity (CBFv) on transracranial doppler (TCD) in the identification of patients at risk for meningitis-associated stroke.     

Trial of dexamethasone treatment for severe bacterial meningitis in adults

Objective: To evaluate the clinical benefit of early adjunctive dexamethasone therapy for severe bacterial meningitis in adults. Design: Multicenter, double-blind, randomized trial initiated in emergency or intensive care units in France and Switzerland. Within 3 h after initiation of an aminopenicillin therapy, patients received dexamethasone (10 mg q. i. d.) or placebo for 3 days. The primary end-point was the rate of patients cured without any neurologic sequelae on day 30. Results: Sixty patients were enrolled, predominantly with a severe form since 85 % required ICU stay and 43 % mechanical ventilation. Streptococcus pneumoniae accounted for 31 cases and Neisseria meningitidis for 18 cases. The study had to be stopped prematurely because of a new national recommendation of experts to use third generation cephalosporin and vancomycin as a result of the increasing rate of penicillin-resistant S. pneumoniae in France. After the third sequential analysis by the triangular statistical test, the difference of rate of cured patients without any neurologic sequelae was not statistically significant (p = 0.0711) between the dexamethasone group (74.2 %; n = 31) and the placebo group (51.7 %; n = 29). Furthermore, the former group was younger and less sick at inclusion. Conclusion: Bacterial meningitis is still a severe disease in adults, since the overall observed rate of death or severe neurologic sequelae was 26.7 %. The reported data are inconclusive regarding a systematic use of dexamethasone as an adjunctive therapy for bacterial meningitis in adults. Moreover this treatment impairs antibiotic penetration into the cerebrospinal fluid (CSF) that can lead to therapeutic failure, particularly in areas with high or increasing rates of penicillin-resistant S. pneumoniae. Received: 21 July 1998 Final revision received: January 1999 Accepted: 15 February 1999     

Acute community-acquired bacterial meningitis in adults: an evidence-based review

Community-acquired bacterial meningitis is still a significant cause of morbidity and mortality. Clinicians should know how to quickly diagnose it, perform a lumbar puncture, order the necessary tests, and start appropriate empiric therapy promptly.     

Acute bacterial meningitis in adults: a hospital-based epidemiological study

Bacterial meningitis, a world-wide disease, has to be reviewed periodically because the specific micro-organisms responsible for the infection vary with time, geography and patient age. To determine its incidence and clinical features in Taiwan, we reviewed the microbiological records for cerebrospinal fluid (CSF) and blood cultures, and the medical records of patients with bacterial meningitis admitted between 1981 and mid-1998. Bacterial micro-organisms were demonstrated in the CSF and/or blood in 395 patients with 418 episodes of bacterial meningitis. Streptococcus species were the most common causative micro-organism group, at 23. 21% of all episodes. Its prevalence rate significantly decreased from the first 7 years of study (41.9%) to the last 10.5 years (19. 2%). However, Klebsiella meningitis and Staphylococcal meningitis were more frequently noted after 1987. More than 70% of patients had at least one underlying disease or condition. Poor prognostic factors indicated by univariable analysis were: age >60 years; diabetes mellitus; severe neurological deficits on the first day of treatment; infection with Gram-negative bacilli; CSF WBC count >5000x10(6)/l; malignancy; seizure; and bacteraemia. The overall mortality rate was 29.4%, 29.7% in the first 7 years of study and 29. 4% in the last 10.5 years. The use of new antibiotics has not reduced the mortality rate in our patients with bacterial meningitis.     

Candidal meningitis following bacterial meningitis

Patients with bacterial meningitis and posttraumatic and/or postsurgical access to the CSF are at risk for superinfection with Candida species. Patients who are not improving on appropriate antimicrobial chemotherapy for bacterial meningitis or are deteriorating after initial improvement should have a CSF reexamination for Candida superinfection.     

New issues in bacterial meningitis in adults. Antibiotic resistance has complicated treatment

The epidemiologic factors of bacterial meningitis, a serious disease that must be addressed with great urgency, have evolved dramatically in the last 25 years. Among both adults and children, multidrug-resistant Streptococcus pneumoniae has emerged as a clinical challenge and has greatly complicated the empirical management of this disease. In this article, the author focuses on new issues involving the epidemiologic factors, diagnosis, treatment, and prevention of bacterial meningitis in adults.     

Acute bacterial meningitis

Despite advances in medical care including antibiotics and vaccines, meningitis still has a high morbidity and mortality rate, especially in certain high-risk patients. Early diagnosis with the administration of appropriate antibiotics remains the key element of management. This article highlights methods of diagnosis, differential diagnoses, treatment options, and complications of treating bacterial meningitis.     

Neuraminidase activity in bacterial meningitis

The relation of neuraminidase to morbidity and mortality was examined in patients with Haemophilus influenzae, meningococcal, and pneumococcal meningitis. Ten strains of H. influenzae and eight strains of meningococci from infected cerebrospinal fluid (CSF) did not elaborate neuraminidase. Each of 27 strains of pneumococci from infected CSF elaborated both neuraminidase and N-acetylneuraminic acid (NANA) aldolase. There was no correlation between amount of neuraminidase secreted in vitro and survival of patients.Values for free and total NANA concentrations were derived from admission CSF samples of 63 patients with meningitis; 18 patients infected with Neisseria meningitidis, 10 with H. influenzae and 35 with Diplococcus pneumoniae. Mean values for total NANA were elevated in each type of bacterial meningitis; however, abnormal concentrations of free CSF NANA were detected only in 17 patients with pneumococcal meningitis. 11 of 18 patients with pneumococcal meningitis showing normal free CSF NANA concentrations were cured, whereas only 4 patients with abnormal free NANA levels survived without residua. Both coma and bacteremia occurred significantly more often among patients with elevated concentrations of free CSF NANA. The association of elevated concentrations of free CSF NANA with coma and with an adverse prognosis suggested that neuraminidase may be a factor in the pathogenesis of penumococcal meningitis.     

Migraine-like headache in bacterial meningitis

The effect of sumatriptan has not been previously described in the treatment of the headache of meningitis, although this headache has similarities to migraine. This study presents the clinical features of two patients who had fulminant bacterial meningitis with migraine-like headache and who experienced no improvement in headache intensity after administration of sumatriptan 6 mg s.c. On these grounds the lack of response of this type of headache to sumatriptan is discussed.     

Recent survey of infectious meningitis in adults: review of laboratory findings in bacterial, tuberculous, and aseptic meningitis.

Infectious meningitis in adults was reviewed to establish the frequency of meningitis due to each causative agent and to reexamine the laboratory parameters that help to distinguish aseptic, bacterial, and mycobacterial meningitis. Aseptic meningitis occurred 2.2 times more often than bacterial and mycobacterial meningitis combined. The most common nonviral causative agent was the pneumococcus (23 cases) followed by the tubercle bacillus (11 cases) and the meningococcus (5 cases). Cerebrospinal fluid (CSF) Gram stain was the most useful study to rule in a bacterial cause: 89% of cases of bacterial meningitis had a positive initial Gram stain. Hyponatremia occurred in 73% of cases of tuberculous meningitis; hyponatremia combined with a negative Gram stain was highly suggestive of a tuberculous cause. One third of all patients with tuberculous and aseptic meningitis had a predominance of neutrophils in the CSF. No patient with aseptic meningitis had a CSF while count higher than 2,800 cells/cu mm or a CSF protein value higher than 250 mg/100 ml. Other reviews confirm this if cases due to lymphocytic choriomeningitis (LCM) are excluded. One patient with tuberculous meningitis in this series, and none of those cases reviewed, had a CSF white count higher than 1,200 cells/cu mm. Only 3.7% of the patients with aseptic meningitis had hypoglycorrhachia. Series reporting exclusively disease due to mumps and LCM have a higher frequency of hypoglycorrhachia.     

Haemophilus influenzae meningitis in adults

Haemophilus influenzae meningitis is rare in adults. We reviewed the microbiological records of cerebrospinal fluid (CSF) and blood cultures and the medical records of patients with bacterial meningitis admitted to Chang Gung Memorial Hospital from January 1978 to May 1996. Haemophilus influenzae meningitis was found in six adult patients, accounting for 1.8% of 326 bacteriologically proven adult cases of meningitis diagnosed between January 1984 and May 1996. Predisposing conditions included head trauma and/or neurosurgical procedure in four patients and an extracranial extension of a pituitary adenoma in a diabetic patient. None of them had altered consciousness on the day of treatment. A CSF cell count less than 500 × 10⁶ leukocytes/liter was noted in three patients. Antibiotic therapy was successful in all patients. Thus, predisposing conditions, particularly head trauma and/or neurosurgical procedure, are commonly present in adult patients with H. influenzae meningitis. Patients with the infection may have a low cellular count in the CSF that may be readily misinterpreted as meningitis caused by other pathogens.