CLINICAL APPLICATIONS

LUMBAR PUNCTURE

Gray ’ s Anatomy for Students: 108 – 116

Netter: 155 – 156, 163 *

Clinical Application

A lumbar puncture uses a spinal needle to access the subarachnoid space between the 2nd and 4th lumbar vertebrae (L2 and L4) to withdraw cerebrospinal fl uid for analysis ( Fig. II-1 ).

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F IGURE II-1. F IGURE II-2.

Anatomic Landmarks

• Below the L2 vertebra. Feel spinous processes and space between processes ( Fig. II-2 ).

• Supracristal plane crosses L4. Puncture is safe just superior or inferior to this point, which avoids the spinal cord.

• Superfi cial to deep: Skin Subcutaneous tissue Supraspinous ligament Interspinous ligament Ligamentum fl avum (provides increased resistance

to needle) Dura mater Subarachnoid space – cerebrospinal fl uid

F IGURE II-3.

* The Clinical Applications in each section are cross-referenced to the following sources: Gray’s Anatomy for Students , 2e, and Netter: Atlas of Human Anatomy , 5e. Page references from each source are provided for procedures in the Clinical Applications.

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F IGURE II-4. F IGURE II-5.

EXTRADURAL ANESTHESIA (CAUDAL OR SACRAL BLOCK)

Gray ’ s Anatomy for Students: 116

Netter: 155, 158

Clinical Application

Introduce anesthetic solutions into the epidural space, which will anesthetize the spinal nerves exiting the dura mater.

Anatomic Landmarks ( Figs. II-4 and II-5 )

• Natal cleft • Sacral cornu • Superfi cial to deep:

Skin Subcutaneous tissue Posterior sacrococcygeal ligament (increased

resistance) Sacral canal

Sacralization is the anomalous fusion of the 5th lumbar vertebra (L5) to the 1st sacral vertebra (S1) ( Fig. II-3 ).

TRIANGLE OF AUSCULTATION

Gray ’ s Anatomy for Students: 91

Netter: 171

Clinical Application

The triangle of auscultation defi nes an area that allows better auscultation with a stethoscope (due to less overlying muscle mass), to maximize listen-ing to the lungs, 6th intercostal space, and the gas-troesophageal junction on the left and assessing potential pathology.

Anatomic Landmarks

• Medial border of scapula • Lateral border of trapezius • Superior border of latissimus dorsi Note: Area of triangle increases when arms are crossed and trunk is fl exed.