Chapter 17 ■ Lumbar Puncture 107

remove the needle, and try one interspace above or

below, using a new needle for each attempt.

8. Collect CSF for diagnostic studies. Allow CSF to flow

passively into the collection tubes; never aspirate with a

syringe. Accurate opening pressure measurement is

possible in a quiet infant.

a. Collect 1 mL of CSF in each of three to four tubes.

b. Send first sample for bacterial culture.

c. Send last sample for cell count, unless fluid becomes

visibly more bloody during the tap.

d. Send the remainder for desired chemical and microbiologic studies.

e. Look for clearing of fluid in successive collections

in the event of a traumatic tap.

9. For myelography or instillation of chemotherapeutic

agents, it is not necessary to remove CSF.

10. For treatment of hydrocephalus, remove 10 to 15 mL/kg of

CSF, or collect until CSF flow ceases (up to 10 minutes).

11. Replace the stylet before removing the needle to prevent entrapment of spinal nerve roots in the extradural

space. Remove the needle, and place an adhesive bandage over the puncture site.

F. Complications (1,2,36)

In older children and adults, headache is the most common

complication following LP, occurring in up to 40% of

patients (36). There is no clear evidence that headache

occurs in infants. In neonates, the most common complication is transient hypoxemia from positioning for the procedure (9–11). In some reports, this is seen in a majority of

cases and depends on the method of positioning used. Also

common, occurring in up to one-third of LPs in neonates

(26,27), is contamination of the CSF sample with blood

from puncture of the epidural venous plexus on the posterior surface of the vertebral body (traumatic tap). Other

potential complications listed below are rare, occurring in

about 0.3% of LPs (36).

1. Hypoxemia from knee–chest position (9–11)

2. Contamination of CSF sample with blood (traumatic

tap) (26,27)

3. Aspiration

4. Cardiopulmonary arrest

5. Sudden intracranial decompression with cerebral herniation (37,38)

6. Infection

a. Meningitis from LP performed during bacteremia

(incidence about 0.2%) (39,40)

b. Discitis (41)

c. Spinal cord abscess (42)

d. Epidural abscess (42,43)

e. Vertebral osteomyelitis (43)

7. Bleeding

a. Spinal epidural hematoma (44)

b. Spinal or intracranial subdural hematoma (45,46)

c. Spinal or intracranial subarachnoid hematoma

(46,47)

8. Epidural CSF collection (48–51)

9. Intraspinal epidermoid tumor from epithelial tissue

introduced into the spinal canal (23)

10. Spinal cord puncture and nerve damage if puncture

site is above the level of cord termination (see discussion in E2 concerning cord termination in preterm

infants) (28)

11. Sixth-nerve palsy caused by removal of excessive CSF

with resulting traction on the nerve (52)

12. Deformity of the lumbar spine secondary to acute spondylitis (53)

References

1. Lehman RK, Schor NF. Neurologic evaluation. In: Kliegman RM,

Stanton BF, St. Geme JW, et al, eds. Nelson Textbook of Pediatrics.

19th ed. Philadelphia: Elsevier; 2011:1998.

2. Michelson DJ. Spinal fluid evaluation. In: Swaiman KF, Ashwal S,

Ferriero DM, eds. Pediatric Neurology. 4th ed. Philadelphia:

Mosby; 2006:153.

Fig. 17.4. Inserting spinal needle in slightly cephalad direction

to avoid vertebral bodies.

Fig. 17.5. Needle has penetrated the dura, and stylet has been

removed to allow free flow of spinal fluid.