Case presentation
A 68-year-old Japanese man (height 171 cm, weight 78 kg) with no background of immunosuppression presented to the Outpatient Department of Juntendo University Hospital (1,051-bed university-affiliated hospital), in Tokyo, Japan, complaining of weakness in the lower limbs, slurred speech, and lower back pain. The patient had a medical history of chronic atrial fibrillation, and hypertension, for which had been treated with rivaroxaban and calcium channel blockers. On examination, he was conscious, his body temperature was 36.9 ℃, blood pressure was 74/59 mmHg, heart rate was 116 beats/minute, and respiratory rate was 17/minute. Oxygen saturation was 97% on room air. Diffuse muscle tenderness was noted in all four extremities (manual muscle test was 4/5), with numbness in the right upper and lower limbs. Initial laboratory findings revealed a leukocyte count of 10.4x109/L (normal range of 3.9x109- 9.7x109/L), hemoglobin of 16.5 g/dL, platelet count of 58x109/L, creatinine of 2.88 mg/dL, and C-reactive protein (CRP) of 27.97 mg/dL. The creatinine kinase (CK) level was significantly elevated to 37370 U/L, and the blood myoglobin level was 11850 ng/mL. His urine was reddish-brown in color, but culture test was negative. Considering his renal function (estimated glomerular filtration rate of 18.2), and risk of contrast material-induced nephrotoxicity [2], a non-contrast computed tomography (CT) scan was conducted. An abdominal CT revealed a 26-mm-diameter hypodense lesion in the right lobe of the liver (Fig. 1). Chest X-ray and CT showed no abnormality. Based on all the findings, the patient was diagnosed with rhabdomyolysis and was immediately started on hydration at 3000 ml/day. He was admitted to the general ward. His serum CK level decreased to 24637 U/L, and his creatinine level to 1.9 mg/dL at 9 hours after admission.
On the 3rd hospital day, the patient developed respiratory insufficiency and was transferred to our intensive care unit (ICU). Because of hypoxemia, he was intubated, and mechanical ventilation was started. Arterial blood gas showed metabolic acidosis and hypoxemia (pH 7.30, pCO2 45 mmHg, pO2 84 mmHg, HCO3- 22.4 mmol/L, lactate 3.2 mmol/L, under FiO2 0.8). Another CT scan revealed multiple newly emerged inflammatory infiltration shadows in the lung and enlarging hypodense lesions in the liver compared to that on admission (Fig. 2). Newly emerged retropharyngeal abscesses and psoas major abscesses were also detected (Fig. 3). Therefore, two sets of blood cultures and urine cultures were performed, and intravenous meropenem (6 g/day) and vancomycin (2 g/day) as well as other supportive treatments were started immediately. On the 4th day, laboratory findings revealed a leukocyte count of 12.7x109/L, platelet count of 24x109/L, CRP of 34.63 mg/dL, and procalcitonin (PCT) of 29 ng/mL. His body temperature increased to 40.1℃. Based on his rapidly deteriorating general status and hypotension requiring crystalloid infusion and vasopressors (norepinephrine 0.1 µ/kg/min and vasopressin 0.03 U/min), he was diagnosed with septic shock. Both blood and urine cultures showed hvKP with a positive string test. To adsorb endotoxin, polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) treatment was performed for twice (18 hours and 18.5 hours, respectively). Due to such intensive care, he recovered from septic shock, vasopressors were discontinued, and pulmonary oxygenation (PaO2/FiO2) improved to 234 mmHg after PMX-DHP treatment. Vancomycin was stopped on the 9thhospital day.
Although his general status improved, inflammation due to the multiple abscesses was prolonged. As the liver abscess was too small and the risk with percutaneous drainage at first outweighed the benefit, the abscess gradually became enlarged (Fig. 4). On the 12thhospital day, ultrasonic-guided percutaneous drainage of the liver abscess was carried out. Twenty-five milliliters of pus was drained; the catheter placed was indwelling. Stab culture of the liver abscesses also revealed Klebsiella pneumoniae . On the 18thhospital day, drainage of the retropharyngeal abscess and tracheostomy were conducted, and he was weaned from mechanical ventilation. Finally, his CK level dropped to normal on the 22nd hospital day. Because inflammatory mediators remained high, percutaneous drainage of the psoas major abscess was performed guided by CT scan on the 28th hospital day. After this drainage, his condition gradually improved, even though meropenem was administered for almost 2 months. He was discharged from the ICU to the general ward on the 33rd hospital day. His physiotherapy rehabilitation continued for 3 months, and he was transferred to a rehabilitation hospital on the 142nd hospital day.