CT head before lumbar puncture in suspected meningitis
Date First Published:
December 19, 2007
Last Updated:
December 21, 2007
Report by:
Gareth Jones, ST1 (CMT) (Countess of Chester Hospital)
Search checked by:
John Sloan, Countess of Chester Hospital
Three-Part Question:
In [adults with suspected meningitis with no neurological abnormality] is [CT head] necessary to exclude [contraindication to lumbar puncture]?
Clinical Scenario:
A previously well 40 year old female is admitted with fever, headache, neck stiffness & photophobia. No neurological deficit is found on examination, you wonder whether LP can be safely performed without the need for a CT scan?
Search Strategy:
Search Terms: (CT.TI. OR Computed tomography.TI.) AND (lumbar puncture.TI. OR spinal puncture.TI. OR LP.TI.)
Limited to Abstracts
Limited to Abstracts
Search Details:
Medline 1950 to date (MEZZ)
Outcome:
20 results, 6 useful papers - 3 relevant to 3 part question
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Computed tomography of the head before lumbar puncture in adults with suspected meningitis Hasbun-R, Abrahams-J, Jekel-J, Quagliarello-V-J. 2001 USA | 301 adults (over 16) with suspected meningitis in the Emergency department Mean age = 40 (range 18-93) |
Prospective Cohort | Incidence of CT results that prevented LP | 1.7% (4/235) | Confidence intervals not provided Information on complications not available on 8 patients *clinical features include:immuncompromised/history of CNS disease/seizures |
| Probability of normal CT in a patient with no abnormal clinical features* (Negative Predictive Value) | 0.97 (93/96) | ||||
| Estimated potential reduction in CTs | 41% (96/235) | ||||
| Cranial computed tomography before lumbar puncture: a prospective clinical evaluation Gopal-A-K, Whitehouse-J-D, Simel-D-L, Corey-G-R. 1999 USA | 111 Adults (over 18) requiring urgent LP in the Emergency department Mean age = 42 (range 19-77) |
Prospective Cohort | Incidence of CT results that prevented LP | 2.7% (3/111) | Only 36.9% of LPs performed to rule out Meningitis (n=41) Large Confidence Intervals - may only suggest a minimal decrease in the likelihood of disease Radiographers not blinded & scans not independently reviewed. Neurological examination not defined. |
| Likelihood of no contraindication on CT when neuro exam normal (Negative Likelihood ratio) | 0 (0-0.63) | ||||
| Estimated potential reduction in CTs | 31.5% (35/111) | ||||
| Role of computed tomography before lumbar puncture: a survey of clinical practice Greig-P-R, Goroszeniuk-D 2005 UK | 64 Adults (over 16) considered for LP in 6 Month period Mean age = 42 (range 16-83) |
Retrospective Case note review | Incidence of CT results that prevented LP | 9.4% (6/64) | Only 35.9% of LPs considered to rule out Meningitis (n=23). CT/Neuro examination criteria not defined. Scans not independently reviewed |
| Probability of normal CT given a normal neurological examination (Negative Predictive Value) [Excluded ?SAH cases] | 0.93 (0.79-1) |
Author Commentary:
CT criteria for predicting patients at risk of herniation with LP are not well established. 7 patients in the prospective studies received LP despite mild to moderate mass effect on CT – none experienced significant ill-effect. Only 2 patients herniated, neither had received a Lumbar Puncture.
None of the patients with normal clinical features had severe mass effect on CT, and none experienced fatal complications of LP. A delay was demonstrated in time to LP by first CT scanning but no statistically significant delay in time to treatment was shown – this has been suggested elsewhere and that such a delay increases mortaility(a)
(a) Proulx, N. Frechette, D. Toye, B. Chan, J. Kravcik, S. Delays in the administration of antibiotics are associated with mortality from adult acute bacterial meningitis. QJM 2005 98(4):291-298
None of the patients with normal clinical features had severe mass effect on CT, and none experienced fatal complications of LP. A delay was demonstrated in time to LP by first CT scanning but no statistically significant delay in time to treatment was shown – this has been suggested elsewhere and that such a delay increases mortaility(a)
(a) Proulx, N. Frechette, D. Toye, B. Chan, J. Kravcik, S. Delays in the administration of antibiotics are associated with mortality from adult acute bacterial meningitis. QJM 2005 98(4):291-298
Bottom Line:
In cases of suspected meningitis it is very unlikely that patients without clinical risk factors (immunocompromise/ history of CNS disease/seizures) or positive neurological findings will have a contraindication to lumbar puncture on their CT scan
If CT scan is deemed to be necessary, administration of antibiotics should not be delayed.
If CT scan is deemed to be necessary, administration of antibiotics should not be delayed.
References:
- Hasbun-R, Abrahams-J, Jekel-J, Quagliarello-V-J.. Computed tomography of the head before lumbar puncture in adults with suspected meningitis
- Gopal-A-K, Whitehouse-J-D, Simel-D-L, Corey-G-R.. Cranial computed tomography before lumbar puncture: a prospective clinical evaluation
- Greig-P-R, Goroszeniuk-D. Role of computed tomography before lumbar puncture: a survey of clinical practice