question need answers

IS CT SCAN MANDATORY BEFORE LUMBER PUNCTURE ?

IS LUMBER PUNCTURE CONTRAINDICATED IN ANY CASE OF INCREASE INTRA CRANIAL PRESSURE?

WHAT DO U THINK ABOUT EXPERT OPINION?

6 years old Saudi boy with history of headache, fever and vomiting.

Presented with focal convulsion

Suspected to have meningoencephalitis

CT scan done & showed no shifting , no mass , but moderately narrowed 3rd ventricle

Was reported by radiologist in other hospital as mild cerebral edema .

Started on ( ceftriaxone, vancomycine and acyclovair)

After 48 hours of management

Patient clinically was stable with GCS 14/15

without any CNS deficit

Ophthalmology ex not done.

shall we repeat imaging before lumber puncture??!!

No need for CT scan prior LP if full CNS exam is normal & no contraindication

( )

MCH MAKKAH KSA

No need to repeat the CT scan if pt is clinically well & no CNS deficit but it depend only on the assessment

( )

KAU JEDDAH

Even if GCS is 15/15 with documented cerebral edema I can’t take risk w/o imaging but I will go for MRI for more detail and better view coz cerebral edema can deteriorate any time within 3 days & if normal MRI I will do LP

ARMED FORCE HOSPITAL-RIYADH

I will repeat the CT scan coz pt had weakness then I will do LP if normal

MCH AZIZIAH-JEDDAH

I can’t do it for all patients coz it depend on the patient situation & the time

AL AZHAR UNIVERSITY

I will not do CT for the pt before the LP if CNS exam is normal.

AL KHARTOM UNIVERSITY

Professor of Neurobiology

HARVARD UNIVERSITY

: IS CT SCAN MANDATORY BEFORE LUMBER PUNCTURE

NO.

CT brain is normal in most cases of purulent meningitis, including those involving subsequent herniation.

The best predictive ability of neuroimaging forbrainlesion is anticipated in cases with contraindications for LP.

- Exclusion of conditions that may mimic bacterial meningitis with raised ICP :

- Posterior fossa tumors

- Acute hydrocephalus

- Cerebral abscess

- Intracranial bleeding

For the patient with meningitis whose response to therapy is suboptimal or development of neurological signs:

- Brain abscesses

- Brain parenchymal changes

- Subdural effusions

Normal CT brain does not rule out raised ICP

Normal CT brain does not rule out herniation after LP

CT examination risks a delay in the start of antimicrobial management of meningitis

Possible radiation effect of CT imaging

CT scan brain is considered unhelpful as it is normal in 69.8% of uncomplicated cases of acute bacterial meningitis.

No clinically significant CT scan abnormalities were found that was not unsuspected on clinical assessment.

CT scan brain only provides structural information and does not measure intracranial pressure.

122 patients admitted for suspected acute bacterial meningitis. Interposition of CT scan brain before LP delayed initiation of antibiotics therapy by an average of 2 hrs. Rennick et al found that CT scan brain was normal in 5 of the 14 children at or about time of herniation. Several reasons have been proposed to explain why CT scan brain cannot reliably detect cerebral herniation.

1. Considerable variability in the size of normal lateral ventricles.

2. Purulent material may prevent narrowing of the subarachnoid and ventricular spaces.

3. Meningeal hardening from inflammation may cause decreased meningeal compliances.

A prospective study involving 301 adults with suspected meningitis confirmed that clinical features could be used to identify patients who are likely to have abnormal CT scan findings. Predictors of abnormal findings included:

i. immuno-compromised status

ii. presence of signs that are suspicious of space-occupying lesions

iii. moderate-to-severe impairment of consciousness

The overall clinical impression made by physicians was shown to have the highest predictive value in identifying patients with CT defined contraindications to LP.

History and physical examination can correctly guide us in reaching a decision of whether to do or delay LP.

IS LP CONTRAINDICATED IN ANY CASE OF INCREASE INTRA

CRANIAL PRESSURE?

Absolute contraindications for lumbar puncture:

1- midline shift.

2- posterior fossa mass

3- loss of the superior cerebellar cistern

4- Loss of the quadrigeminal plate cistern

Relative contraindications for lumbar puncture include:

1- increase intracranial pressure.

2- coagulopathy.

3- brain abscess.

• Patients who are older than 60 years

• Patients who are immunocompromised

• Patients with known CNS lesions

• Patients who have had a seizure within 1 week of presentation

• Patients with an abnormal level of consciousness

• Patients with focal findings on neurologic examination

• Patients with papilledema seen on physical examination, with clinical suspicion of an elevated ICP

In a recent prospective investigation by Hasbun et al. none of the 7 patients with mild-to-moderate mass effect on head CT scan experienced brain herniation after undergoing LP.

Furthermore, 4 patients had mass effect on head CTthat caused their treating clinicians not to perform LP. Two of those 4 patients experienced brain herniation despite not undergoing LP.

Having mass effect on a CT did not predict post-LPherniation, and not performing a LP for patients with mass effect did not prevent herniation.

A prospective description of 38 patients with focal mass lesions on CT who underwent LP found that only 1 patient (2.6%) experienced brain herniation after LP.

Similarly, in older studies, of 495 patients with brain tumors who underwent LP, only 1 (0.2%) developed a complication from the LP.

including several performed prospectively, is that CT cannot reliably be used to predict who will or will not experience brain herniation after LP.

Intraventricular

I.V monitors are considered the "gold standard" of ICP monitoring catheters. They are surgically placed into the ventricular system and affixed to a drainage bag and pressure transducer with a three-way stopcock. Intraventricular monitoring has the advantage of accuracy, simplicity of measurement, and the unique characteristic of allowing for treatment of some causes of elevated ICP via drainage of CSF.

Intraparenchymal

Intraparenchymal devices consist of a thin cable with an electronic or fiberoptic transducer at the tip. The most widely used device is the fiberoptic Camino system. These monitors can be inserted directly into the brain parenchyma via a small hole drilled in the skull. Advantages include ease of placement, and a lower risk of infection and hemorrhage (<1%) than with intraventricular devices

Subarachnoid

Subarachnoid bolts are fluid-coupled systems within a hollow screw that can be placed through the skull adjacent to the dura. The dura is then punctured, which allows the CSF to communicate with the fluid column and transducer

Epidural

Epidural monitors contain optical transducers that rest against the dura after passing through the skull. They often are inaccurate, as the dura damps the pressure transmitted to the epidural space, and thus are of limited clinical utility

Waveform analysis

ICP is not a static value; it exhibits cyclic variation based on the superimposed effects of cardiac contraction, respiration, and intracranial compliance. Under normal physiologic conditions, the amplitude of the waveform is often small, with B waves related to respiration and smaller C waves (Traube-Hering-Mayer waves) related to the cardiac cycle.

-Pathological A waves (also called plateau waves) are abrupt, marked elevations in ICP of 50 to 100 mmHg

Q4 : DO YOU WILL DO LUMBER PUNCTURE WITHOUT CT??

PUBMED.

OXFORD JOURNAL

JOURNAL OF PAEDIATRIC ( CHINA)

AMERICAN ACADEMY OF NEUROLOGY.

UPTODATE

Farley A, McLafferty E. Lumbar puncture. Nurs Stand. Feb 6-12 2008;22(22):46-8.

Reichman E, Simon RR. Emergency Medicine Procedures. New York, NY: McGraw-Hill; 2004.

Roberts JR, Hedges JR. Clinical Procedures in Emergency Medicine. 4th. Philadelphia, PA: Saunders; 2004.

Cooper N. Lumbar puncture. Acute Med. 2011;10(4):188-93.