Meningitis: hypotension, altered mental status and seizures at admission increased the risk of dying in-hospital.

Clinical bottom line (level 2b)

  1. A quarter of patients who have community-acquired bacterial meningitis died in-hospital.
  2. Patients were at increased risk of dying in-hospital with bacterial meningitis if they had hypotension, altered mental status or seizures at admission.
Aronin et al: Annals of Internal Medicine 1998; 129: 862-869
Expires November 2003

The study

Retrospective cohort study with objective outcomes, adjusted for confounding factors, validated in an independent set of patients.

Setting: 4 hospitals, USA

269 patients (aged range 16 to 91 years; median 57, 53% male) Community-acquired bacterial meningitis and a microbiologically identified bacterial cause. Meningitis diagnosed on the basis of a compatible clinical picture and a positive cerebrospinal fluid culture, or a negative cerebrospinal fluid culture with one or more of: a positive result on cerebrospinal fluid bacterial antigen or Quelling test, a positive blood culture in the presence of cerebrospinal fluid pleocytosis (leukocyte count = 10 cells mL of fluid) or identification of gram-negative diplococci after Gram staining of cerebrospinal fluid.

Excluded if
  • incorrect International Classification of Diseases, Ninth Revision, diagnosis code was applied
  • case definition was not fulfilled
  • incomplete medical record
  • patient's meningitis episode was not the first episode in the study period
  • lumbar puncture not performed or performed >24h after admission
  • meningitis caused by mycobacterium species, treponema pallidum or borrelia burgdorferi
  • intracranial devices



    • Factors studied:
  • hospital mortality
  • hypotension systolic blood pressure <91 mmHg or a >39 mHg decrease in systolic blood pressure
  • altered mental status lethargy, disorientation or coma
  • seizures


    • Appropriate antibiotics were given to patients.

    Multiple logistic regression was used to adjust for confounding factors.

    100% followed for to hospital discharge
    Outcomes studied:
  • hospital mortality

    • Patients were divided into the derivation cohort (n=176) and a validation cohort (n=93).

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    hospital mortality to hospital discharge 73/269 27.1%
    (21.8% to 32.5%)

    prognostic factor for
    hospital mortality     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    hypotension ? 47/135
    (35%)     		2.75
    (1.22 to 6.18)     		5
    (2 to 30)
    altered mental status ? 3/29
    (10%)     		6.56
    (1.71 to 25.2)     		7
    (6 to 16)
    seizures ? 54/154
    (35%)     		4.42
    (1.56 to 12.5)     		4
    (2 to 17)

    • Using the three independently predictive variables (hypotension, altered mental status and seizures), the authors created prognostic stages by stratifying patients who had 0,1 and at least 2 of the variables into low (stage I), intermediate (II) and high-risk subgroups (III).
    • The effect of antibiotic timing when patients remained at the same prognostic stage from arrival until their first dose of antibiotics, was determined by the time delay in initiation of therapy was compared for those with and those without adverse clinical outcomes. Median delay was 4.0 hours and the number of episodes with an adverse clinical outcome was 4.5; the number of episodes without an adverse outcome was 3.9 (p-value >0.20).

    Comments

    1. Prognostic model validated within the retrospective data did not adequately separate the risk strata

    Citation

    1. Aronin SI, Peduzzi P, Quagliarello VJ: Community-acquired bacterial meningitis: Risk stratification for adverse clinical outcome and effect of antibiotic timing. Annals of Internal Medicine 1998; 129: 862-869
    Contributor: Clare Wotton & Bob Phillips, November 1999
    Reviewer: Malcolm Daniel

    Clinical Question.
    Patient community-acquired bacterial meningitis
    Intervention or Exposure what prognostic factors
    Outcome mortality