To the Editor:
The pulmonary artery catheter (PAC) has been used extensively in the management of the critically ill (1). In patients at high risk of pulmonary emboli, a second device, the inferior vena cava (IVC) filter, may be indicated. We report a case of a potential interaction between a preexisting IVC filter and a newly placed PAC.
A 53-year-old female patient was admitted to the intensive care unit after extensive thromboembolectomy of the arteries of her left upper extremity. One week previously, the patient had been diagnosed with bilateral lower extremity deep venous thromboses and subsequently with pulmonary embolism despite therapeutic anticoagulation. An IVC filter (Greenfield) had been placed, apparently without complications.
Because of persistent hypotension and oliguria, a PAC was placed to better manage her hemodynamics and intravascular volume status. The catheter was advanced through a right subclavian PAC introducer. A right atrial tracing was obtained without difficulty, but it was not possible to visualize a right ventricular tracing at the expected distance of catheter insertion. After several attempts, a right ventricular waveform was noted at an insertion depth of 45 cm and a pulmonary arterial waveform at 52 cm. Upon review of the chest radiograph (Fig. 1) performed to confirm placement, the catheter was noted to have passed through the right atrium and into the IVC. It proceeded down the IVC, whereupon it turned and coursed back to the right atrium, into the right ventricle, finally exiting the pulmonary outflow tract. The catheter was withdrawn without sequelae. A new catheter was placed with a pulmonary capillary wedge pressure at 49 cm without incident.
We suspect the IVC filter may have interacted with the PAC, altering its course. Alternatively, the catheter may have looped in the IVC independent of the IVC filter. Irrespective of the cause, this case reinforces the point that, in general, a PAC should not be advanced more than 35–40 cm without identifying a ventricular waveform. This may be especially important in patients with an IVC filter, as the distance from the subclavian vein to the most common filter location (infrarenal) can be as little as 35–45 cm (2).
Although entanglement of a PAC in an IVC filter has been described, (3,4) it appears to be either very uncommon or underreported. It is important to note that in the two reported cases of PAC entrapment, (3,4) percutaneous retrieval was unsuccessful and surgical removal was required. (Surgical retrieval was successful in one and was refused by the second patient who died 4 days later from an unrelated cerebrovascular event). If a PAC or central line wire does become entangled with an IVC filter, care must be taken to avoid excessive force while attempting to withdraw it, and strong consideration should be given to fluoroscopic assistance to aid in its removal.
Daryl J. Kor, MD
Mark T. Keegan, MB, MRCPI
Kenyon W. Kruse, MD
C. Mark Bazzell, MD
1. Williams G, Grounds M, Rhodes A. Pulmonary artery catheter. Curr Opin Crit Care 2002;8:251–6.
2. Barraco RD, Scalea TM. Dislodgment of inferior vena cava filters during central line placement: case report. J Trauma 2000;48:140–2.
3. Gibson MP, Chung RS, Husni EA, Kuivinen EP. Dislodgment and entrapment of a Greenfield filter. J Vasc Interv Radiol 1999;10:378–9.
4. Frezza EE, Kagan SA. Entrapment of a Swan Ganz catheter in an IVC filter requiring caval exploration: a case report. J Cardiovasc Surg (Torino) 1999;40:905–8.