TIPS, and infection may be related to clot formation or direct bacterial seeding (endotipsitis). Clinicians should assess with blood cultures from multiple sites and evaluation of the stent initially with Doppler ultrasound for the presence of stenosis or clot. In the absence of other etiologies for fever, patients should receive intravenous antibiotics targeted toward enteric organisms.
Bleeding
Worsening liver function due to the underlying liver disease can cause a decrease in hepatic production of clotting factors. Prior to TIPS insertion, assessment of coagulation panel should be performed and any bleeding diathesis corrected. Most patients who will experience bleeding as a complication to their TIPS insertion do so perioperatively, and it is not a common presentation to the emergency department.
Stent Obstruction
Creation of a TIPS introduces a stent across hepatic tissue from the hepatic vein to the portal vein. Hepatic tissue reacts to this placement and begins to create a pseudo‐intima around and into the shunt. Increase in tissue into an uncoated stent begins to narrow the lumen of the stent and decrease the portosystemic blood flow, making the stent less effective. This then allows portal hypertension to recur, and patients have an increased risk in esophageal variceal bleeding and redevelopment of ascites.
Doppler ultrasonography is used as the initial screening method for shunt stenosis. Two main parameters are used for shunt patency. First, the velocity of flow within the TIPS is measured in multiple locations across the shunt. Single velocity measurement has a lower sensitivity and specificity than multiple measurements, with decrease in shunt velocity between 40 and 60 cm/s of significant elevated velocity over 200 cm/s identifying local stenosis. Main portal vein velocity is the second parameter. Stenotic shunts demonstrate lower main portal velocity and a change in the direction of flow toward the liver instead of normally away from the liver in a functioning stent. CT angiography can also be used in the evaluation of shunt stenosis; however, the gold standard of diagnosis of shunt stenosis is angiography. Stenotic shunts can be dilated during angiography and the placement of an additional stent ensures unobstructed flow of the TIPS.
Hemolytic Anemia
Patients presenting with an increase in jaundice after TIPS placement should be evaluated for hemolysis. TIPS‐related hemolysis develops one to two weeks after TIPS creation and seems to be related to shearing of red blood cells or mechanical trauma of cells within the stent. Often, in patients, there is an evidence of increased unconjugated bilirubin and high reticulocytosis, which may mean the patient is only slightly anemic, if at all. If patients develop severe hemolytic anemia, the clinician can consider blood transfusion. Most TIPS patients will spontaneously improve as their stent endothelializes.
Consultation
Patients receive TIPSs as a stabilizing entity for portal hypertension, which has numerous causes. TIPS placement is not curative, and these patients will continue to be managed with gastroenterologists for their underlying disease. When considering consultation and management of these patients, the involvement of gastroenterology is often helpful.
Mechanical complications of TIPS stents, including occlusion or malplacement that leads to worsening liver disease, will need to be addressed with interventional radiology. While the patient needs to be stabilized medically for their presenting problem, clinicians need to consider either the involvement of interventional radiology (IR) or transfer to a center with IR capabilities for definitive management.
Further Reading
1 1 Chockalingam, A., Holly, B., and Hong, K. (2017). Transjugular intrahepatic portosystemic shunt. In: Current Surgical Therapy (eds. J. Cameron and A. Cameron), 402–411. Philadelphia: Elsevier.
2 2 Colambato, L. (2007). The role of transjugular intrahepatic portosystemic shunt (TIPS) in the management of portal hypertension. J. Clin. Gastroenterol. 41 (Suppl. 3): 344–351.
3 3 Conn, H. (1996). Hemolysis after transjugular intrahepatic portosystemic shunting: the naked stent syndrome. Hepatology 23 (1): 177–181.
4 4 Darcy, M. (2012). Evaluation and management of transjungular intrahepatic portosystemic shunts. Am. J. Roentgenol. 199: 730–736.
5 5 Jakhete, N. and Kim, A. (2017). The management of hepatic encephalopathy. In: Current Surgical Therapy (eds. J. Cameron and A. Cameron), 417–421. Philadelphia: Elsevier.
6 6 Li, J. and Henderson, J.M. (2001). Portal hypertension. In: Surgical Treatment: Evidence Based and Problem Oriented (eds. R.G. Holzheimer and J.A. Mannick), 306–319. Munich: Zuckschwerdt.
7 7 Somberg, K.A., Riegler, J.L., LaBerge, J.M. et al. (1995). Hepatic encephalopathy after transjugular intrahepatic portosystemic shunts: incidence and risk factors. Am. J. Gastroenterol. 90 (4): 549–555.
5 Indwelling Central Venous Catheter Devices
Anna Weiss
Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
Division of Emergency Medicine, Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
Introduction
The continual advancement of treatment for chronic diseases has brought with it an increased emphasis on allowing patients with long‐term medical needs to receive much of their care in the outpatient setting. In this context, the use of indwelling central venous catheters (CVCs) has become a mainstay in the management of adults and children with chronic illness. CVCs provide patients with stable routes for life‐saving infusions – including parenteral nutrition, blood transfusions, and chemotherapeutic agents – and allow for reliable venous access in patients who require frequent blood draws or whose peripheral vasculature no longer adequately supports recurrent venipuncture. Because of their placement in the large vessels of the central vasculature, CVCs can be used to infuse medications that are otherwise vesicants in peripheral vessels, and they are often the preferred means of administration for infusions containing high concentrations of electrolytes and/or dextrose.
As the number of patients receiving care in the community via CVCs increases, so too does the number of patients with CVCs presenting to the emergency department (ED). For this reason, ED practitioners must be familiar with both the routine care of these devices, as well as with the workup and management of their most common and most serious complications. When a patient with an indwelling CVC presents to the ED, the clinician must have a high index of suspicion for – and must be able to recognize – the symptoms of catheter‐related complications, particularly as the patient's presenting complaint may not initially implicate the device.
Central Venous Catheter Types
The first tunneled CVC was introduced by Broviac in 1973, and since then, the variety of indwelling CVCs on the market has increased dramatically as their use has become more commonplace. As the list of available CVCs is extensive, practitioners should make a particular effort to become familiar with the devices most commonly encountered in their practice setting. In general, devices are referred to either by their trade name (e.g. Broviac©, Hickman©) or by their type (e.g. implanted port, peripherally inserted central catheter [PICC]). They can be externalized, as is the case with the Broviac, Hickman, and PICC devices, or they can be fully implanted – requiring needle access through intact skin – as is the case with implanted ports. Both externalized and implanted CVCs can have multiple lumens, and knowledge of a particular CVC's lumen count is often important when managing the device's complications.