There is high incidence of skin cells in the first and third drops of cerebrospinal fluid in spinal anesthesia.

Background and objectives: Skin fragments during lumbar punctures may develop intraspinal epidermoid tumors. The aim of this study was to determine the incidence of epithelial cells that reflow along with the fi rst and third drops of CSF of patients undergoing spinal anesthesia.

Methods: Samples of the fi rst and third drops of cerebrospinal fluid were collected from 39 adult patients undergoing spinal anesthesia with a 25G Quincke needle. Four microscope slides were prepared: one for the fi rst drop, one for third drop, one for the needle, and one with a drop of saline for control. A pathologist examined the slides randomly.

Results: Squamous epithelial cells were identified in 35 (89.7%) samples from the fi rst drop, 34 (87.2%) from the third drop, and 24 (61.5%) from spinal needle. The third drop showed a mean number of cells larger than the fi rst drop (p = 0.046). Nucleated epithelial cells were found in a sample of the fi rst drop (2.56%), in four samples of third drop (10.25%), and in one spinal needle (2.56%). Third drop showed a mean number of nucleated cells higher than fi rst drop with no statistical difference (p = 0.257).

Conclusions: High percentage of epithelial cells was found in the fi rst (89.7%) and third (87.2%) drops of CSF reflow and in used needles (61.5%). Skin cells were found even using small gauge disposable needles with well-adapted mandrel.