Influence of Physical Characteristics on Skin to Lumbar Epidural Space Distance in Nigerian Adults

Aims: To estimate the skin to lumbar epidural space distance (SLESD) in Nigerian adults and determine the influence of age, height, weight and body mass index on it.

Study Design: It was a cross sectional descriptive study carried out on consenting patients enlisted for surgery with planned lumbar epidural anaesthesia. Patient selection was by a non-probability sampling technique.

Place and Duration of Study: The study was carried out at the Main theatre complex of the University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria from February to April, 2012.

Methodology: One hundred and twenty healthy adults of both sexes consisting of 60 consenting patients each, scheduled for elective surgeries under epidural anaesthesia were recruited. With asepsis precaution, epidural anaesthesia was established in the sitting position using a midline approached at L3L4 interspace. The epidural space was identified by loss of resistance to saline. The SLESD was read off from the centimetre markings on the needle by subtraction of the length of the needle outside from the whole length and rounded off to the nearest 0.25 cm. Pearson correlation coefficient was used to determine the relationship between SLESD and age, height, weight, body mass index (BMI) and the differences between males and females.

Results: The mean SLESD was 5.29 cm ± 0.06 ranging from 4 cm to 7 cm. Females had a slightly longer SLESD (5.37 cm) than the males (5.21 cm). The SLESD was significantly influenced by weight and BMI both having a P value .000. Height showed a negative correlation which was significant in both males and females with P = .01 and .015 respectively. Age had a significant correlation with SLESD only in females increasing with age.

Conclusion: The SLESD in Nigerian Adults is strongly influenced by weight, BMI and height. Age influences SLESD only in females.