Title: Comparison of Pre-Procedure Ultrasound with Real time Ultrasound in Right Internal Jugular Vein (IJV) cannulation in patients undergoing major surgery

Introduction:

Central Venous Catheterization is done for administration of fluids, hyperosmolar therapy, antibiotics, haemodynamic monitoring and haemodialysis in patients undergoing major surgery (1). Many anatomic landmark guided techniques for internal jugular vein (IJV) puncture have been described since 1966. Different methods of cannulation have been described that includes landmark guided and ultrasound guided central venous cannulation (2).

Landmark technique:

It is based on anatomical location of the vessel and identification of surface or skin anatomic landmarks. The needle is then inserted blindly until blood is aspirated. In landmark technique a guide wire is passed in the vessel through which CVC cannulation is done (Seldinger’s technique) (3).

Ultrasound guided Central Venous Cannulation:

Ultrasound guided central venous cannulation was started in 1984(4). In this technique a linear probe USG probe (8-15MHz) is used to scan the target vessel, and cannulation is attempted under guided ultrasound. Although Real time ultrasound is gold standard technique for CVC cannulation and has been widely used technique, it has a long learning curve and require a well-trained clinician.

Pre-procedural ultrasound:

Pre-procedure ultrasound can be used as an alternative technique where in USG guided scanning of neck done with skin markings, prior to cannulation. It is followed by direct cannulation based on the skin markings. In this technique no learning curve is required, and cannulation can be attempted easily (5,6).

 There is paucity of literature regarding pre-procedure ultrasound assisted CVC cannulation. This study being planned to compare the cannulation time, number of attempts, Success rate after 3^rd attempt and any early complications associated with central venous cannulation between pre-procedure ultrasound guided CVC cannulation with real time USG guided CVC cannulation.

Aims and Objectives:

Primary Objective:

1.     To compare the cannulation time between Pre-procedure vs Real Time USG guided CVC cannulation

Secondary objectives:

1.     To compare cannulation attempts

2.     To compare success rates after 1^st and 3^rd attempt

3.     To detect early complications

Methodology:

The study will be conducted in Operation Theatre at SGPGIMS under the Department of Anaesthesiology in patients undergoing major surgery necessitating the central venous cannulation after approval from the institutional Ethical Committee (IEC) undergoing major surgery. The total study duration for the study will be 24 months. The Procedure will be performed after General Anesthesia as per Institutional Protocol.

Inclusion Criteria:

1.     Adult Patients (18 years to 60 years)

2.     Patients posted for elective surgery (ASA I, II and III) requiring CVC cannulation

3.     Patients who will give written informed consent

Exclusion criteria:

1.     Any infection at the site or anatomical variations 

2.     Thrombosed right internal jugular vein (IJV)

3.     Pre-existing coagulation disorders/Deranged International Normalized Ratio (INR)

4.     Patients with permanent pacemaker implant

5.     Those patients who do not give written consent

After a thorough pre-operative evaluation, all patients will receive the standardized monitoring protocols including Heart rate, Blood Pressure, Pulse Oximetry, Temperature, Continuous ECG and Capnography. All patients will be induced as per prespecified protocol and procedure will be carried out under general anesthesia with controlled mechanical ventilation.

Sample size collection:

Based on the data on 5 patients in the same centre, canulation time of the in the group P (Pre procedure USG) and group U (Real time USG guided) were 14.25±1.70 and 18.75±2.99 seconds respectively [Effect size of the mean difference: 1.854949]. Taking the effect size of the mean difference of 0.5, at minimum two-sided 95% confidence interval and 90% power of the study, estimated sample size in each group was 86. To ensure of these number, after taking the consideration of the data loss, 100 patients to be targeted to include in each of the two groups. Sample size was calculated using software G*Power version 3.1.9.2.

Group P: Pre procedure ultrasound guided Rt. IJV cannulation.

Group U: Real Time Ultrasound Guided Rt. IJV cannulation.

Pre-Procedure Ultrasound:

Under all aseptic precautions, the preferred site will be prepared and draped. Patient’s head will be turned towards opposite side (around 15-20 degree). Trendelenburg supine position will be achieved with 30 degrees head tilt. USG will be used to scan the neck and antero-lateral area with 2‘D USG image with 6-18 MHz linear assay probe.

Rt. IJV regarding its course, calibre, patency and relationship to the nearby carotid artery and nerves will be visualized and marked at 3 levels with a gap of 1 cm along it’s course along with one mark at level of carotid artery using sterile marker. Skin puncture using 18 G wide bore needle will be done from the mid-point keeping the needle towards the distal point till the free flow of blood appear. A guide wire will be passed through the needle into right IJV. A 7.5 Fr triple lumen CVC catheter will be railroaded over the guidewire using Seldinger’s techniques and will be fixed at 11.0 cm and will be covered with sterile fixator (Tegaderm).

Real Time Ultrasound Technique:

Under all aseptic precautions, the preferred site will be prepared and draped, and Trendelenburg position will be achieved same as in group P. Under Direct visualization through ultrasound, Right IJV puncture (out of plane technique) will be done using under 18 G wide bore needle till the free flow of blood appears. A guide wire will be passed through the needle into the target vessel and will be reconfirmed through USG Probe followed by 7.5 Fr triple lumen CVC catheter insertion.

Data Collection: The data will be recorded by independent observer in terms of:

 1. Cannulation time

2. Cannulation attempts

3. Total duration of successful cannulation

4. Early complications (if any)

Cannulation time will be measured from the time of needle insertion to skin to J-wire in. Cannulation attempt will be defined as a single skin puncture. Total duration of successful cannulation will be defined as time taken from needle insertion till complete blood aspiration through all ports and waveform appearance in monitor.

Statistical analysis:

Continuous variables will be presented in Mean and standard deviation (SD) or median (interquartile range) depend upon normality status. To compare the change in difference of means / medians between two groups, independent samples t test / Mann Whitney U test to be used. Two-way repeated measures ANOVA will be used to test the association between study groups and change over the time.

Categorical variables will be presented in number (%) and compared by the Chi-square test / Fisher exact test. Statistical analyses will be performed using SPSS   software for windows, version 23.0 (SPSS, Chicago, IL). P value <0.05 to be considered as statistically significant.