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Acute Hypoxia after TIPS Procedure in the Radiology Suite
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A 58-year-old Caucasian female with decompensated cryptogenic cirrhosis and refractory ascites, currently on the liver transplant list, is scheduled for an urgent TIPS procedure.
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What does a TIPS procedure entail? What are its indications and contraindications?
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TIPS (transjugular intrahepatic portosystemic shunt) involves the passage of a catheter, usually inserted through the internal jugular vein and directed into the liver, which creates a low-resistance conduit between a portal vein and a hepatic vein by deployment of an intrahepatic expandable stent. Hemodynamically, this allows immediate decompression of portal hypertension by partial or complete diversion of portal flow from hepatic sinusoids into the inferior vena cava and the systemic circulation.
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Indications for the TIPS procedure include: variceal bleeding not controlled by endoscopic or medical therapy, intractable ascites, hepatic hydrothorax, Budd-Chiari syndrome, hepatorenal syndrome and hepatopulmonary syndrome, and bridge to liver transplantation. Some contraindications of TIPS are: primary prevention of variceal hemorrhage, congestive heart failure, severe pulmonary hypertension and tricuspid regurgitation, severe hepatic failure, hepatocellular carcinoma, active intrahepatic or systemic infection, and severe coagulopathy or thrombocytopenia.
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What are the anesthetic strategies for TIPS? What are some preoperative and intraoperative concerns in these patients?
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TIPS can be performed under moderate sedation, monitored anesthesia care, or general anesthesia. Given the usual need for long immobilization, potential risk of aspiration, and significant comorbidity, general anesthesia is often the recommended anesthetic plan.
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Preoperative considerations include: risk of aspiration, gastrointestinal bleeding, decreased functional residual capacity from ascites, pleural effusions, coagulopathy, thrombocytopenia, and hepatic encephalopathy. Special intraoperative considerations should include careful hemodynamic monitoring (usually via arterial catheter), frequent performance of blood gases for electrolyte abnormalities and coagulation parameters, and testing to determine blood glucose and urine output levels. Altered pharmacokinetics of anesthetic agents should also be kept in mind.
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Following informed consent and plan for general anesthesia, the patient is induced with etomidate, fentanyl, and succinylcholine, using rapid sequence induction; atraumatic intubation is accomplished uneventfully. Prior to placement of the TIPS, the radiologist evacuates approximately 8 L of ascitic fluid.
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What are your concerns about this paracentesis? How would you balance these hemodynamic fluid shifts?
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Large volume paracentesis is believed to be a relatively safe and effective procedure; however, it can lead to paracentesis-induced circulatory dysfunction (PICD), a frequently occurring silent complication. PICD is characterized by a marked activation of the renin-angiotensin axis, as well as accentuation of an already established arteriolar vasodilatation that may be combated with salt-free albumin as the plasma expander of choice, especially if at least 8 L are evacuated.
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The TIPS procedure lasts about 2 hours; the patient is reversed appropriately with neostigmine and glycopyrrolate. She emerges smoothly and is transferred to the PACU on oxygen via a face mask at 6 L/min. Within 15 min of admission to the PACU, the patient complains of mild chest pain and shortness of breath. Bilateral wheezing is noted, followed by crackles at the bases.
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What are some complications of TIPS procedure? How would you attempt to manage this patient?
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Complications following TIPS are not insignificant; 3-month mortality has been reported to be approximately 32% to 45%. Complications can be broadly categorized as being associated with the anesthesia, patient comorbidity, and procedure. Patient- and anesthesia-related factors are similar to the ones described in the previous section. With regard to procedure-related factors, special note should be made of cardiopulmonary consequences resulting from a sudden increase in pulmonary artery pressures and systemic pressures, leading to pulmonary congestion.