A previously healthy 62-year-old Caucasian man was admitted to our hospital for acute respiratory failure. Our patient developed a fever of up to 40 C seven days earlier and a non-productive cough three days later. He had not received any antimicrobial treatment prior to his hospitalization, the diagnosis of his primary care physician being influenza (A/H1N1v), given the ongoing outbreak.
His medical history was remarkable for possible viral pericarditis without any consequence in 2007 and a gastric ulcer 30 years earlier. He had no drinking habits. He did not smoke cigarettes. He had not travelled abroad recently. He did not have any bird or pet.
On hospital admission, our patient was in acute respiratory distress. His respiratory rate was 40 breaths/minute, his temperature 38.3 C, his pulse 98 beats/minute and his blood pressure 114/60 mmHg. Auscultation revealed crackles over his whole left lung and over his right lower lung field. A computed tomography scan showed diffuse alveolar type infiltrates in his two lung fields with air bronchograms (Figure 1).
Arterial blood gas analysis (under 100% oxygen through a non-rebreathing mask) showed pH 7.54, a partial pressure of carbon dioxide (PaCO2) 44 mmHg, partial pressure of oxygen (PaO2) 38 mmHg and an arterial blood oxygen saturation of 84%. His white blood cell count was 5780 cells/muL (86% neutrophils) and the erythrocyte sedimentation rate was 92 mm/h. Laboratory values showed serum creatinine at 1.7 mg/dL, potassium at 2.8 mEq/L, creatine phosphokinase at 644 IU/L, liver test alterations (alanine transaminase at 87 IU/L), lactate dehydrogenase elevation (1708 IU/L) and D-Dimers at 7420 ng/mL, activated partial thromboplastin time of 72 seconds, normal international normalized ratio and blood platelets at 166.000/muL. His urine output was 0.4 mL/kg/h over six hours. An electrocardiogram showed a sinus tachycardia with a complete right bundle branch block.
Serum samples obtained every week as from the day of admission showed a clear-cut seroconversion for C. pneumoniae antibodies (the course of the antibody titers shown in Table 1).
Paired serum samples and antigens against the most common microorganisms, including atypical bacteria and common viruses such as A/H1N1v, were negative. Blood, sputum and urine tests for bacterial cultures obtained during the first day of hospitalization were negative.
Our patient was treated by amoxycillin-clavulanic acid, moxifloxacin and oseltamivir. His respiratory status necessitated endotracheal intubation and mechanical ventilation. Severe arterial hypotension prompted norepinephrine infusion and the insertion of a pulmonary artery catheter. The initial hemodynamic pattern was typical for sepsis (hemodynamic values are shown in Table 2). Metabolic data showed a mixed venous saturation of 56%.
Despite maximal ventilatory support (high positive end expiratory pressure, an inspired oxygen fraction (FiO2) of 1.0, nitric oxide inhalation of 20 ppm, neuromuscular blocking agents and prone positioning), our patient remained severely hypoxemic (PaO2/FiO2 = 38) which led us to initiate ECMO treatment.
Venovenous ECMO (a Sorin Revolution centrifugal pump, a Sorin ECCO oxygenator and a Sorin Satcrit console from Sorin Group, Milano, Italy) was put in place on the fifth day of hospitalization, with a left femoral 22-Fr drainage cannula and a right femoral 23-Fr return cannula, inducing a drastic improvement of our patient's oxygenation parameters (PaO2 = 120 mmHg). The mixed venous oxygen saturation (SVO2) increased from 56% to 86%. Continuous veno-venous hemodiafiltration (CVVHDF) renal replacement therapy was also initiated on day three because of acute renal failure.
There were no severe complications of the ECMO treatment except for hemorrhagic suffusion of the two femoral catheter insertion points, requiring a blood transfusion.
ECMO and CVVHDF were withdrawn on day 12. Our patient was extubated on day 18 and discharged from our Intensive Care Unit on day 20. He went home a month later. He is now in good physical condition and has returned to work and to a normal social life.