For more complex problems, including intraluminal mineral/precipitant occlusion or lipid emulsion occlusion, refer to the staff caring for the catheter LUMBAR PUNCTURE Indications To obtain cerebrospinal fluid (CSF) for the diagnosis of meningitis, meningoencephalitis, subarachnoid hemorrhage, and other neurologic syndromes To measure opening pressure to diagnose idiopathic intracranial hypertension Complications Contamination of the CSF sample with blood from the epidural venous plexus Local back pain—occasionally with short-lived referred limp Headache (uncommon in children younger than 10 years of age) Apnea/hypoventilation caused by positioning for the procedure in young infants Spinal epidural/subdural hematoma or spinal cord bleeding—especially in the presence of bleeding diathesis Infection Subarachnoid epidermoid tumor formation Ocular muscle palsy (transient) Epidural CSF leak—ranging from asymptomatic to cauda equina syndrome 10 Brainstem herniation—in the presence of a mass effect or noncommunicating hydrocephalus Equipment Commercial trays; CSF manometers; spinal needle—22 gauge; 3.75 cm (1.5 in) for younger than year old, 6.25 cm (2.5 in) for year to middle childhood, and 8.75 cm (3.5 in) for older children and adolescents; povidone-iodine or chlorhexidine antiseptic solution; topical 4% lidocaine cream Procedure Lateral Decubitus Position Restrain the patient in the lateral decubitus position Maximally flex the spine without compromising the upper airway Often, in infants younger than months, the patient’s hands can be held down between the flexed knees with one of the assistant’s hands The other hand can flex the neck at the appropriate time The spinal cord ends at approximately the level of the L1 and L2 vertebral bodies Caudal to L2, only the filum terminale is present The desired sites for LP