The Correlation Between Body Mass Index On The Length From Skin To Lumbar Epidural Space In Nigerian Adults

One of the factors that determine success of an epidural anaesthetic is correctly locating the epidural space. Being able to predict the skin to lumbar epidural space distance can serve as a guide to performing epidural anaesthesia and in turn increase the success rate.

To determine the correlation between the BMI, gender and age on SLESD of adults scheduled for elective surgical procedure under lumbar epidural anaesthesia.

It was across sectional descriptive study carried out on consenting patients scheduled for elective surgery under lumbar epidural anaesthesia.

The study was carried out in the main theatre complex and the obstetric theatre of the University of Ilorin Teaching Hospital, Ilorin, Nigeria.

One hundred and twenty patients of ASAI and II physical status between the ages of18-65years scheduled for elective surgical procedures under epidural anaesthesia were enrolled into the study. This was a cross sectional descriptive study involving both sexes. Using a septic technique epidural anaesthesia was established in the sitting position using the midline approach at L3/L4orL4/L5 interspace. The epidural space was identified by loss of resistance to air. TheSLESD in centimetres (cm) was rounded up to the nearest 0.25cm. Data were collected and analyzed using Spearman´s correlation to evaluate the relationship between BMI, weight, sex, age, height and the SLESD.

The mean SLESD was 4.60±0.83 cm with a range of 3cm-8cm. The SLESD was significantly influenced by BMI and weight with both having positive correlation and P value of 0.001 and 0.004 respectively. We formulated a relationship between skin to lumbar epidural space and body mass index based on linear regression analysis: Depth cm= a + b × (BMI)Where a =3.33 and b =0.05.There was no correlation between SLESD and height, age or sex of the patients.

There was positive linear correlation between the body mass index, body weight and the skin to lumbar epidural space distance. Whereas, the age, sex and height had no correlation with the skin to lumbar epidural space distance.