Extracorporeal cardiopulmonary support for cardiogenic shock caused by pheochromocytoma: a case report and literature review.

A 47-yr-old woman was brought to her local hospital because of nausea, vomiting, diffuse myalgias, and deterioration in mental status. She had been well until the night before, when, while dancing at a party, she had reported epigastric–retrosternal discomfort, right lumbar pain, and vomiting with an impending sense of doom. She had no history of hypertension, diabetes, or cardiovascular diseases. She was a nonsmoker and nondrinker, had no allergies, and was not taking any regular medications. On admission, she was alert but anxious and confused. Her blood pressure was 100/50 mm Hg, her pulse was 120/min, her respiratory rate was 28/min, and her body temperature was 39.8°C. Physical examination was unremarkable. An electrocardiogram showed a sinus tachycardia with aspecific alteration of ventricular repolarization; the corrected QT interval was 405 ms. Echocardiography demonstrated severe biventricular dysfunction (left ventricular ejection fraction, 30–35%) and grade 2 mitral and tricuspidal regurgitation. Laboratory values showed leukocytosis, hyperazotemia, hypocalcemia, lactic acidosis, and increased levels of transaminases, amylases, total creatine kinase and MB fraction, troponin I, and C-reactive protein (table 1). Arterial blood gas analysis showed lactic acidosis (partial pressure of oxygen [PO2], 107 mm Hg; partial pressure of carbon dioxide [PCO2], 31.9 mm Hg; pH, 7.43; bicarbonate, 22.7 mM; base excess, 2.5; lactate, 5.7 mM). The patient was given intravenous fluids and was immediately transferred to the intensive care unit. Further blood chemistry confirmed a multiorgan-failure syndrome with shock, massive rhabdomyolysis (total creatine kinase, 4,519 U/l; myoglobin, 10,790 ng/ml), progressive renal failure, hepatic cytolysis, disseminated intravascular coagulation (platelets, 59,000/ l; prothrombin time international normalized ratio, 1.95; fibrinogen, 246 mg/dl; D-dimer, 18,446 g/l; antithrombin III, 64%), and respiratory failure. The patient was intubated and mechanically ventilated. The most common toxic causes of rhabdomyolysis were excluded: The patient was not taking any medication associated with myopathy (lipid-lowering drugs, antiretroviral drugs, corticosteroids, cyclosporine), and toxicologic tests on blood and urine were negative for cocaine, opiates, amphetamines, ecstasy, and alcohol. An arterial line and pulmonary artery catheter were inserted. Blood pressure was 90/50 mm Hg; pulmonary artery pressure was 35/25 mm Hg; central venous pressure and pulmonary artery occlusion pressure were 7 and 20 mm Hg, respectively; cardiac index was 2 l · min 1 · m; and mixed venous blood saturation (SvO2) was 59.7%. Inotropic support with dobutamine and norepinephrine was started. On a presumptive diagnosis of severe septic shock, a broad spectrum antimicrobial therapy with meropenem and metronidazole was started. Hydration, forced diuresis (with loop diuretics and fenoldopam), and urine alkalinization were instituted. Despite initial therapy, the patient rapidly developed acute renal failure necessitating renal replacement therapy. Because this treatment was not available in the unit of admission, she was transferred to our intensive care unit. The differential diagnosis included an acute viral infection causing myocarditis and hepatitis or an atypical presentation of a vasculitic syndrome. Complete viral and autoimmune tests yielded negative results, as well as serial cultures of blood, urine, and respiratory secretions. A computed tomography scan revealed an adrenal mass with a radiologic aspect highly suggestive of a pheochromocytoma (fig. 1). Continuous venovenous hemofiltration was instituted to support renal function. Hemodynamic conditions also deteriorated, with marked increase of ventricular filling pressures (up to central venous pressure values of 27 mm Hg and pulmonary artery occlusion pressure values of 37 mm Hg) and a cardiac index of 2.6 l · min 1 · m despite maximal support with vasoactive drugs. Passive venous congestion due to right ventricular failure led to a progressive worsening of liver function, with marked increases of transaminases and bilirubin (up to 18.9 mg/dl), further impairment of coagulation, and reduction of indocyanine green clearance (plasma disappearance rate, 2.8%). We decided to institute venoarterial extracorporeal bypass. A 24French cannula was positioned percutaneously into the right common femoral vein, and a 12-French arterial catheter was inserted into the right common femoral artery. Venous blood was drained from inferior vena cava and propelled by a centrifugal pump (Jostra Rotaflow; Maquet Cardiopulmonary AG, Hechingen, Germany) through an artificial lung (Jostra Quadrox; Maquet Cardiopulmonary AG) for gas exchange before returning it into the arterial circulation. Extracorporeal blood flow was initially set to 5 l/min and gas flow through the artificial lung adjusted to maintain normal pH and PCO2. Anticoagulation was maintained with continuous infusion of unfractionated heparin, titrated to an activated clotting time of 190–210 s. * Staff Anesthesiologist, Department of Perioperative Medicine and Intensive Care, ‡ Staff Member, Department of Clinical Pathology, Ospedale San Gerardo, Monza. † Researcher, Department of Experimental Medicine, Milano-Bicocca University, Ospedale San Gerardo, Monza. § Professor of Anesthesia and Intensive Care, Department of Experimental Medicine, Milano-Bicocca University. Director, Department of Perioperative Medicine and Intensive Care, Ospedale San Gerardo, Monza.