Pulmonary embolus as a complication of a central venous catheter

Abstract

A 46-yr-old female with chronic intestinal pseudo-obstruction was referred to the Geisinger Medical Center Nutrition Support Clinic for evaluation and management. A right subclavian doublelumen Hickman catheter had been placed 2.5 years earlier for total parenteral nutrition (TPN) following significant weight loss and unsuccessful attempts with enteral nutrition. She remained dependent on TPN for weight maintenance, and also used her venous access for morphine infusion. She was followed closely by pain management consultants for chronic abdominal pain. During our initial consultation, unsuccessful attempts were made to aspirate blood specimens from the catheter. The patient stated that blood sampling from the catheter had not been possible for months, but no problems with infusion were occurring. Urokinase 5000 U/mL was instilled on two occasions, but blood withdrawal was not accomplished. Physical assessment revealed minor venous collaterals on the inferior aspect of the right arm. No jugular venous distension or swelling of the right arm was noted. Two months later the patient experienced increasing difficulty with her infusions. Repositioning her arm would allow the infusions to continue, but repeated occlusion alarms by the infusion pump and awkward body positions were interfering with her sleeping pattern. One lumen became completely occluded and the patient was forced to use the remaining available lumen for morphine during the day and her TPN at night. This situation provided poor pain control and frustration for the patient. The patient attempted to restore the patency of the catheter herself. She forcefully irrigated the occluded port of her Hickman catheter with a tuberculin (1 mL) syringe. She experienced a “pop” as the catheter opened. Subsequently, the patient experienced sharp left-sided chest pain and acute shortness of breath. The patient remained at home that evening, and presented to our cliic the next morning. Though she was in no acute distress when she arrived in our clinic, her left-sided chest pain could be reproduced by turning her head to the left or raising her left arm. She denied shortness of breath, fevers, sweats, or chills. The chest pain was not pleuritic and did not radiate. Jugular venous distension or arm edema was not observed. No calf or thigh tenderness was noted. Given the symptoms described by the patient, a pulmonary embolus (PE) was suspected. Diagnostic evaluations, including an electrocardiogram, chest radiograph, and duplex doppler studies of the subclavian and internal jugular veins were all normal. A pulmonary ventilation pert%sion scan was moderately probable for a PE with a mismatch in the left upper lobe. This site corresponded to her region of chest discomfort. A pulmonary arteriogram was considered, but was felt unlikely to change the treatment plan. The Hickman catheter was removed that day. Pathology report noted a 4-cm fibrin sheath on the outer surface of the catheter. The contents of the catheter yielded membranous fragments with clusters of crystals. The patient was discharged from the outpatient clinic with temporary peripheral intravenous access for hydration, and morphine infusion. A new double lumen Broviac was inserted contralateral to the old site within the week. She was able to resume her TPN and morphine infusions. Heparin (6OLIO units) was added to her TPN admixture and low-dose oral warfarin (1 mg) prescribed. She suffered no further sequelae from this incident. A follow-up ventilation perfusion scan performed 2 months later showed resolution of the mismatch.