A Cross-sectional Study to Determine
the Relationship between Various
Anthropometric Indices and Depth of Spinal
Needle Insertion in Indian Patients undergoing
Elective Surgeries under Spinal Anaesthesia
UC06-UC09
Correspondence
Anish H Dave,
1602, UG PG Hostel, Boys Wing, KEM Hospital, Parel, Mumbai, Maharashtra, India.
E-mail: anishhdave1992@gmail.com
Introduction: The estimation of Depth from Skin to Subarachnoid Space (DSS) may be helpful in selecting the appropriate length of the spinal needle before insertion and decrease the chances of accidental dural puncture.
Aim: To determine the usefulness of previously suggested formulae and to derive mathematical formulae to predict DSS for the Indian population.
Materials and Methods: After approval from the Institutional Ethics Committee, 700 American Society of Anaesthesiologists (ASA) Physical Status I and II patients were recruited from August 2017 to July 2018. Patients of either sex in the age group of 18-65 years, undergoing elective surgeries under spinal anaesthesia were included in this cross-sectional study. DSS was measured after Sub Arachnoid Block (SAB) and it was compared with various formula-based predicted DSS. Multivariate regression analysis was done to evaluate the influence of anthropometric indices on DSS and formulae were derived for the Indian population. p<0.05 was considered significant.
Results: Final data analysis was performed on 685 patients. SAB was successful in first attempt in 624 (91.09%) patients, second attempt in 47 (6.86) patients and third attempt in 11 (1.60) patients. There was a failure of SAB in 3 (0.43%) in total analysed subjects. The measured mean DSS was 4.60±0.602 cm. DSS in adult males (4.60±0.5818 cm) was comparable with DSS in adult females (4.61±0.6377 cm). Formula for predicting DSS in the overall population was DSS (cm)=0.8+0.16×BMI. Formulae were also derived based on other variables like weight, Weight-to-Height Ratio (WHR) and Waist Circumference (WC). The strength of correlation between the anthropometric indices and DSS is BMI>WHR>Weight>WC>Height in decreasing order. DSS correlates best with Body Mass Index (BMI) and WHR.
Conclusion: The proposed formulae based on BMI can be used to predict the DSS. It would help in the selection of appropriately sized spinal needle which in turn would reduce the number of attempts and incidence of failure and complications in patients.