COMPARISON OF THREE MANEUVERS TO INCREASE THE SIZE OF THE INTERNAL JUGULAR VEIN IN CHILDREN

Abstract

S311 INTRODUCTION: Liver compression(L), valsalva maneuver(V), and/or placing the child in 15[degree sign] Trendelenburg position(T) are the three maneuvers used to increase the size/cross sectional area (CSA) of the internal jugular vein(IJV) prior to central venous cannulation. [1] This study compares the effects of these maneuvers on the CSA of the IJV using high resolution ultrasound in children. METHOD: With IRB approval and parental consent, 52 children ASA class I or II under the age of 6 years were studied. All were anesthetized, intubated and placed in the supine position. The head was kept in the midline and extended by placing 3 towels under the shoulder. The Aloka[registered sign] ultrasound probe with a 5 MHz transducer was placed on the right side of the neck just above the medial side of the clavicle to visualize the right IJV on the screen. The circumference of the IJV image was delineated by the electronic marker and the CSA was calculated at end- expiration by the Aloka[registered sign] Ultrasound machine using planimetry. A total of 8 measurements per patient were taken of the right IJV with the probe held in the same position with the patient supine (control) (S), and in T position (T), during V maneuver (SV, TV), with liver compression (SL, TL) and a combination of both (SVL, TVL). We arbitrarily decided that an increase of 25% in CSA of the IJV would be clinically relevant. Data were analysed using the Wilcoxon signed rank test and each p-value was adjusted by the Bonferroni method. A p-value < 0.002 is significant at an overall significance level <or=to 0.05. RESULTS: Figure 1 shows the mean CSA values measured with different maneuvers. SV, SVL, TV and TVL produced clinically relevant increase (>25%) in the CSA of the IJV in children. SV was superior to SL and T. Compared to control (S), there was a 32.3% +/- 4.4% increase in the CSA with SV as compared to 12.9% +/- 2.1% with SL and 17.7% +/- 2.8% with T position. The combination of all 3 maneuvers (TVL) produced a 49.6% +/- 5.9% increase in the CSA which was higher than SV, SL, T, TL and TV (p<0.002). There was not a clinically relevant increase in the CSA when TVL combination (49.6% +/- 5.9%) was compared to the SVL combination (42.7% +/- 5.4%).Figure 1: CSA of the IJV (mean +/- SEM): S=Supine(control) SL=Supine + Liver Compression Compression SV=Supine + Valsalva SVL=Supine + Valsalva + Liver Compression T=Trendelenburg TL=Trendelenburg + Liver TV=Trendelenburg + Valsalva TVL=Trendelenburg + Valsalva + Liver CompressionDISCUSSION: The combination of all 3 maneuvers (TVL) increased the CSA of the IJV more than that with SVL. The increase in the CSA with SVL or TVL as compared to SV was statistically significant, but not clinically relevant. We conclude that SV is the single most useful maneuver to increase the CSA of the IJV in children less than 6 years of age.