Point of care ultrasound to confirm correct positioning of central venous catheter tip -A prospective observational study.

Central venous catheter
(CVC) is used in surgical settings and ICU setups for providing fluid
correction, central venous pressure monitoring, for providing total
parenteral nutrition, repeated sampling and providing long term intravenous
drug infusion. It is also preferred method in patient of difficult
cannulation and providing large amount of fluid resuscitation in burns and
trauma patient.

Central
venous catheter is typically inserted into the internal jugular vein,
subclavian vein and femoral vein. Others alternatives sites include the
external jugular vein, cephalic vein and proximal great saphenous vein. It
is recommended to perform high frequency linear probe ultrasound to detect
the insertion site before using it. This should be done before and after
insertion of catheter to detect the CVC tip and other complication The
central line tip should be ideally placed at the junction of superior vena
cava and right atrium that is cavo-atrial junction.

The
complication of CVC depends on the site, patient factors like illness,
variation in anatomy and operator skill and experiences. Acute
complication can happen like cardiac dysrhythmia, hematoma formation,
mechanical injuries to nearby structures like pneumothorax /haemothorax,
arterial wall puncture and other rare complications like air embolism,
malposition and lost guide wire during insertion.

Conventional chest radiography (CXR) is the current gold
standard to examine catheter tip position. Here, chest radiography
(CXR) is the current gold standard to examine catheter tip position
postoperatively. CXR involves the use of ionized radiation, time
consuming and increase in health care expenditure.Use of ultrasound
(USG) combined with saline flush or bubble test to determine the CVC
tip position.

A
rapid injection of 5 ml of agitated saline,as a bolus through catheter,
in a stream of microbubble seen in the right atrium through the tip,
confirming the tip position. the push to bubble time will be measured
to classify the position of tip.