Aims

1. Ultrasound Analysis of the Accuracy of Landmark Approach to Central Neuraxial Blocks in Anaesthesia Lie J1, Venkataraju A1, Bhatia K2 & Kochhar P2  1 Specialty Trainee in Anaesthesia, 2 Consultant Anaesthetist Insert your logos Insert your QR Code Introduction Results • Correct identification of the vertebral level during a central neuraxial block (CNB) would avoid needle damage to the spinal cord which usually ends at L1-2 in adults • An imaginary horizontal line joining the posterior iliac crests (Tuffier’s line) is the most commonly used anatomical landmark by anaesthetists for CNB as it passes through the L4 vertebral body1, 2 • Evidence suggests that ultrasound (US) imaging of the spine by an experienced operator leads to correct identification of vertebral level in >90% of the patients3 • 91 patients Median age: 36 yrs Median height: 164.5 cm Median weight: 77 kg Median Body Mass Index (BMI): 27.9 Kg.m-2 Key Findings • Accuracy of landmark technique: 45.4% • Increased BMI & difficulty of palpation of landmarks >> Statistically significant decrease on accuracy (p=0.0.32* & 0.019* respectively) • 7 out of 68 (10.3%) patients had their spinal/CSE placed above L2 level • No statistically significant correlation between the experience of operator & accuracy (p=0.311*) • * Fisher’s Exact t-Test (2-tailed) 69% (63) Spinal 6% (5) CSE 25% (23) Epidural 40.7% (37) of operators were consultants, followed by 29.7% (27) were senior trainees Aims To determine the discrepancy between conventional landmark technique and Ultrasound to identify site of insertion of Lumbar CNB. No patients should have their spinal/ CSE sited above the L2-3 interspace. Limitations • Small sample size • Heterogeneous population - Obstetric/Non- obstetric, predominantly females • Skin puncture site & positioning • Operator bias Methods Recommendations • Three experienced US operators retrospectively performed the US of spine post-operatively in 91 patients having a lumbar CNB by landmark method • From January to March 2013 • Location: St Mary’s Hospital & Manchester Royal Infirmary • Patient’s demographics, anaesthetic details of CNB & documentation of CNB were noted, including vertebral level at which CNB was performed • US spine was then used to identify the actual vertebral level in which the block was performed at using the visible skin puncture point • Level was compared with documented vertebral level • Difficulty in palpating lumbar anatomy & iliac crest was also recorded Block Level: USG Vs Documentation • All patients having a lumbar CNB should have ultrasound of their spine to identify the correct vertebral level • Easy availability of curvilinear probes • Promote staff education & awareness References Shiraishi N, Matsumura G. What is the true location of Jacoby’s line? Okajimas Folia Anat Jpn 2006; 82: 111–5 Render CA. The reproducibility of the iliac crest as a marker of lumbar spine level. Anaesthesia 1996; 51: 1070–1 Halpern SH, Banerjee A, Stocche R, Glanc P. The use of ultrasound for lumbar spinous process identification: A pilot study. Can J Anaesth 2010; 57: 817–22 Degree of Discrepancy