Radiographic Mislead: Apparent Arterial Placement of Carotid Central Venous Catheter Due to Mediastinal Shift

INTRODUCTION: Optimal placement of central venous catheters (CVC) is essential for giving medications and monitoring of central venous pressure (CVP) in critically ill patients and ensuring long-term use of the catheter in major surgeries.(1) Accidental carotid artery catheterization is one of the most serious complications of the procedure. Radiography is commonly used to ensure optimal placement of CVC tip and rule out carotid artery catheterization in the absence of Doppler ultrasound. Tracheal shift is an indicator of upper mediastinal shift, while a shift in the position of the heart indicates a lower mediastinal shift.(2) Since the pleural cavity is confined by the rib cage, in case of a moderately large pleural effusion, the structures in the thoracic cavity normally get ‘pushed’ to the opposite side resulting in a shift of the upper and lower mediastinum.(2) We present a case of a haemodynamically unstable and hypoxaemic patient with mediastinal shift, in which the Intensivist/physician was in a dilemma about the arterial placement of the right internal jugular vein CVC. The CVC crossing midline due to mediastinal shift give false impression of it being placed in carotid artery rather than the vein.(3,4) Subsequently, it was proved to be correctly placed in IJV. CASE REPORT: 53y/M with Chronic Parenchymal Liver Disease (CPLD) in grade 4 hepatic encephalopathy with acute interstitial pancreatitis with Acute Renal Failure (ARF), with chronic anemia with Pleural effusion in shock presented to casualty in gasping state, hypoxia, shock. His GCS was 3/15, E1V1M1, Pupils bilateral 3mm sluggish reactive to light, over-all edema (Anasarca). Blood pressure-not recordable, Pulse Rate-carotid 140bpm, feeble, regular, peripheral pulses not felt. CVS -S1, S2 heard, No murmurs. RS - bilateral crepts present, right side reduced air entry, RR-36cpm, Sp02-55-60% on RA and 75–85% on bains with 10L/min oxygen. Capillary blood glucose 89 mg/dL. ABG sent from radial artery. With one intravenous 20G cannula, present already, patient was induced with etomidate, paralysed with scoline and intubated after thorough suctioning. Foleys catheter inserted & confirmed. RT inserted & confirmed. As peripheral veins were difficult to access due to Anasarca. On emergency basis Central Venous Catheterization (CVC) secured immediately to Right internal jugular vein (IJV) by single prick first attempt using Seldinger technique & fixed at 14 cms. Backflow in 3 ports confirmed. Blood sent for investigations from CVC. Noradrenaline double strength (NORAD DS) infusion started. Chest x-ray AP view (CXR) taken and shifted to ICU for monitoring. Usually the position of the CVC tip as seen in CXR, should be above & on the right side of carina, and it should never in its course cross the trachea. Our CXR has rotation towards right. (image A) The CVC tip seen crossing the midline with gradual turn leftwards & downwards indicating misplaced CVC in artery. (image A, B) We got mislead by CXR post CVC. As the right lung had moderate-large pleural effusion, the trachea (upper mediastinum) and heart (lower mediastinum) shifted to the opposite side along with cardiac borders which gave the false impression of it being placed in artery rather than the vein. (image B) Subsequently, USG was done to check the placement of CVC in short axis and long axis view. (image D, E) It was observed and proved to be correctly placed in the Right IJV. (image F) ABG from CVC was not sent. The CVC was repositioned to 11 cm. Backflow to all ports present. Repeat CXR done to visualize the CVC tip (image C).