Intraoperative Cardiac Tamponade After Central Venous Cannulation in an Infant During Orthotopic Liver Transplantation

Cardiac tamponade is a rare, life-threatening complication of central venous cannulation. Tamponade is usually caused by perforation of the right atrium (RA) or ventricle (RV) by the catheter tip [1]. There is one reported case of this occurring intraoperatively in an adult [2]. We report a case of iatrogenic intraoperative cardiac tamponade in an infant during orthotopic liver transplantation (OLT). Case Report A 7-mo-old girl weighing 7 kg was anesthetized for OLT for chronic liver disease after Kasai portoenterostomy had been performed at 6 wk. Standard monitoring was applied, anesthesia was induced with thiopental (60 mg), and succinylcholine (20 mg) was used to facilitate nasotracheal intubation. Anesthesia was maintained with inspired isoflurane 1%-1.5% in air/oxygen and infusions of atracurium (0.5 mg [middle dot] kg-1 [middle dot] h-1) and fentanyl (10 [micro sign]g [middle dot] kg1 [middle dot] h-1). Dopamine was infused at 3 [micro sign]g [middle dot] kg-1 [middle dot] min-1, which is part of the standard protocol for OLT at our institution. A 5.0F, 8-cm polyurethane triple-lumen central venous catheter (CVC) was inserted in the right internal jugular vein using the Seldinger technique with a soft J-tip wire. The CVC was inserted without apparent complication and sutured with the 8-cm mark at the skin entry site (midpoint of the sternomastoid muscle), and the middle lumen was transduced for central venous pressure (CVP) measurement. When surgery commenced, the patient's blood pressure (BP) was 80/55 mmHg, heart rate (HR) was 135 bpm, and CVP was 10 mm Hg with a normal atrial waveform. During hepatic dissection, the patient remained stable and responded appropriately to the infusion of fluids. Two hours into the procedure, the patient became hypotensive. This was associated with an increase in HR and CVP. The CVP waveform was unchanged. Fluid volume resuscitation (10 mL/kg) and increasing the dopamine infusion from 3 to 10 [micro sign]g [middle dot] kg-1 [middle dot] min-1 led to a transient improvement in the BP. After approximately 30 min of continued hemodynamic instability, cardiac tamponade was suspected. Transdiaphragmatic pericardiocentesis was performed, and 12 mL of blood was aspirated. This resulted in a rapid improvement in the patient's cardiovascular status (Figure 1). The abdominal incision (Mercedes incision) was extended over the lower sternum. Methylene blue dye was injected through the distal lumen of the CVC and was seen in the pericardial sac. The pericardium was opened, and a contusion was noted on the anterior wall of the RV adjacent to the right coronary artery, but the epicardium appeared intact. The CVC tip was palpable beneath the contusion. The catheter was withdrawn 3 cm so that its tip lay at the junction of the superior vena cava and RA. The pericardium was then closed over a 10F drain, which was also used to drain the right pleural cavity. After discussion, it was considered appropriate to proceed with transplantation, which was completed without further incident. The patient has made an uneventful recovery and was well with normal graft function at 4 mo.Figure 1: Anesthetic record showing hemodynamic response to pericardiocentesis ([down arrow]). SaO2 = oxygen saturation, BP = blood pressure, HR = heart rate, CVP = central venous pressure.Discussion The incidence of acute cardiac tamponade in infants secondary to central venous cannulation is rare (0.3%), but it carries a high mortality (up to 100%) [3]. Tamponade is more common with polyurethane than silicone catheters and usually occurs more than 24 hours after insertion [3,4]. After insertion, the position of all CVCs should be confirmed with a chest radiograph [4]. However, in the operating room, using radiography to confirm the position of CVCs before use is not always practical. Anesthetists most often rely on clinical judgment to estimate the length of the catheter required and observation of the transduced CVP waveform. The manufacturer recommends the distal lumen of the catheter be transduced for CVP measurement. However, the distal lumen of many CVCs has the largest diameter, and if this is used for rapid infusion, the CVP cannot be measured simultaneously. The distal lumen should be intermittently transduced if it is used for transfusion to ensure against catheter tip migration. In practice, the more proximal lumen(s) may be transduced to enable continuous CVP monitoring. Initially, however, correct placement should be confirmed by transducing the distal lumen of the CVC. This case illustrates that, in infants, special care is required to ensure that the catheter tip is correctly positioned and that, if doubt exists, radiography should be used. Beck's triad of cardiac tamponade is hypotension, increased CVP, and tachycardia, but in up to 29% of cases, cardiovascular collapse and death may occur suddenly with only "vague" signs [5]. During OLT, these signs may be difficult to interpret due to surgical manipulation of the liver, torsion of major blood vessels, and rapid changes in the circulating blood volume. In this case, it took approximately 30 minutes to realize that the cause of the hypotension was secondary to cardiac tamponade rather than hypovolemia or cardiac failure. Cardiac tamponade associated with central venous cannulation is probably more common in infants than in adults [1,3]. The RA and RV are thin-walled chambers in the infant and may be more susceptible to trauma. Furthermore, head and neck movements (especially flexion) [6] or cephalad movement of the diaphragm and heart may cause the catheter tip to migrate into the RV [3]. In this case, surgical manipulation and use of the Thompson retractor for surgical exposure may have elevated the diaphragm and played a role in impaction of the CVC tip into the ventricular wall. We conclude that cardiac tamponade after central venous cannulation may be difficult to recognize. Intraoperatively, it must be considered as a possible cause of hypotension in all patients who have a CVC in situ. Measures such as securing the catheter tip in the superior vena cava can prevent this complication [4,7].