Medically Challenging Case

 

Title

Anesthetic Management of a Patient with a Mediastinal Mass and Multiple Myeloma Undergoing Repair of Multiple Orthopedic Injuries

 

Authors

Kimberly Kupinski, Janet Shin, Darab Zarrabi, Jun Tang, Elliot Schwartz

 

Introduction

Our case describes a patient with multiple myeloma and a mediastinal mass who presented with multiple pathologic and impending fractures. She underwent extensive orthopedic procedures in one day in the operating room. Patients with mediastinal masses presenting for surgery can pose a challenge for the anesthesiologist. Depending on the size, these masses can cause significant compression of vital structures and cause airway and hemodynamic compromise. Further complicating the clinical picture, our patient had a diagnosis of multiple myeloma. Neuraxial techniques can certainly be performed in these patients, however, the benefits must be balanced with increased risks of epidural hematoma and other coagulation problems. Our case describes an extensive orthopedic surgery that was performed successfully in a patient with both multiple myeloma and resulting mediastinal mass performed with upper extremity block and spinal anesthesia.

 

Materials and Methods

Patient informed consent was obtained for submission of a case report. IRB approval was waived.

 

Case Report

The patient was a 68-year-old female, BMI 27.8, who presented with dyspnea, fatigue, weakness, right arm pain, and an enlarging chest wall mass over two weeks. She was found to have multiple myeloma with multiple pathologic lytic lesions, of the right radius (complicated by new onset numbness in her fingertips) and the left femur, requiring surgical repair; the chest wall mass was biopsied and shown to be a plasmacytoma. Her medical history was significant for coronary artery disease status post percutaneous coronary intervention; hypertension; anemia; acute kidney injury; and current smoker with 20 pack-years. Her medications included aspirin, amlodipine, and carvedilol. 

 

Preoperative workup included EKG, showing normal sinus rhythm; echocardiogram, notable for EF 65%, normal biventricular systolic function, mild pulmonary hypertension, and a variant left-sided superior vena cava; and chest CT, showing lytic lesions throughout the bones, some associated with soft tissue masses, the largest of which was an anterior chest wall mass with destruction of the manubrium and anterior first ribs (measurements of the mass: 12.4 cm x 5.9 cm x 7.1 cm) and compression on the left innominate vein, and degenerative changes to the spine with spinal stenosis; MRI of lumbar spine showed mild bulging disc at L3-L4 and a thickened ligamentum flavum, and facet hypertrophy resulting in moderate central canal stenosis. Preoperative lab results were notable for elevated creatinine to 1.18, elevated calcium to 16.2, low hematocrit to 25.1, and elevated partial thromboplastin time to 44. 

 

The patient was taken to the operating room for open reduction and internal fixation of the right radius, internal fixation of the right ulna, intramedullary fixation of the left femur and tibia, and radical resection of tumors of the femur, tibia, and radius. Thoracic surgery was on standby in the setting of the mediastinal mass. She was first prepped for the right axillary nerve block, performed under ultrasound guidance with a 21-gauge, 3.5-inch needle using 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine. An intercostobrachial nerve block was performed by anatomic landmarks using 8 mL of 0.25% bupivacaine with 1:200,000 epinephrine. Then, the patient was positioned and prepped for the spinal anesthetic, which was performed in one attempt using 2.6 mL of 0.5% bupivacaine with epinephrine wash. Phenylephrine 100 µg was given to treat a drop in systolic blood pressure from 180 to 126 after spinal placement. Then, the patient was sedated using propofol infusion at 50 µg/kg/min and dexmedetomidine infusion at 0.3 µg/kg/h for the duration of the case. A second peripheral IV was placed before surgical incision was made. Both extremities were repaired simultaneously, though the repair of the lower extremity was completed before the upper extremity, and the surgery lasted for five hours. The patient received 200 µg of fentanyl in 25 µg increments during repair of the upper extremity. She also received 1 g of tranexamic acid during the surgery. The patient was breathing spontaneously and her oxygen saturation remained >95% on 6 L/minute of O₂ by simple face mask. She required a total of 300 µg of phenylephrine throughout the case, but no vasopressor infusions were necessary. She received 2 units of packed red blood cells, 1 unit of fresh frozen plasma, 250 mL of 5% albumin, 1.5 L of crystalloid, and 1.5 g of calcium chloride. Estimated blood loss was 500 mL, and urine output was 200 mL. An additional unit of packed red blood cells was given in the PACU for a hematocrit of 22 at the end of the surgery. 

 

Discussion

Mediastinal masses present a host of challenges in the operating room, particularly in airway and hemodynamic control, to avoid complete cardiovascular or tracheobronchial collapse. Our patient presented with dyspnea and an enlarging chest wall mass. She was able to tolerate lying supine without difficulty. Imaging showed the mass to compress the large vessels, but it did not obstruct the airway. In preoperative discussion with the surgeon, the surgical plan was to address both operative limbs simultaneously, to shorten the total surgical time. Our anesthetic plan thus comprised maintaining spontaneous ventilation for the duration of the case, and to provide surgical anesthesia with a spinal anesthetic and an axillary nerve block. Maintaining spontaneous ventilation is a cornerstone of safe anesthetic management of the patient with a mediastinal mass to prevent airway or great vessel compression. 

 

The diagnosis of multiple myeloma adds another layer of complexity to the anesthetic management of this patient. Disease-specific factors must be considered when formulating the anesthetic plan, including the increased risk for hematoma with neuraxial (particularly with epidural placement), due to thrombocytopenia secondary to pathologic plasma cell proliferation. This patient also had spinal stenosis on imaging, which has a higher risk for neurologic complications after neuraxial anesthesia. Anticipating a relatively short surgery with simultaneous repair of the affected limbs, we opted for spinal anesthesia with a peripheral nerve block for the upper extremity. Communication with the surgeon was paramount in the perioperative period. The surgical time lasted longer than anticipated, for a total of 5 hours. Table 3 presents the advantages and disadvantages of spinal anesthesia, CSE, and general anesthesia for this patient.