The patient, a 76-year-old female, was admitted to the hospital on June 4, 2023, presenting with a three-day history of fever and cough, which escalated to somnolence on the day prior to admission. Initially, she exhibited a fever peaking at 39°C and a paroxysmal dry cough without diurnal variation. Her condition deteriorated the following day, marked by altered consciousness and hypotension, with blood pressure dropping to 70/46 mmHg (1 mmHg = 1.33 kPa). She received interventions to elevate her blood pressure, alongside anti-infective treatment and fluid resuscitation. Her medical history included hypertension, but she denied any history of diabetes, atrial fibrillation, or cardiac valvular disease. Her occupational background in agriculture involved prolonged exposure to domestic poultry, and she reported no smoking or alcohol consumption. Physical examination: Respiratory rate: 22 breaths/min, heart rate: 81 beats/min, blood pressure: 121/77mmHg (Norepinephrine 10mg, 0.37ug/kg/min). Coarse breath sounds and scattered wet rales were noted in both lungs, while cardiac examination revealed a regular rhythm without significant arrhythmias or murmurs. The abdomen was distended without tenderness or rebound pain, and no obvious hepatosplenomegaly was palpable.
Post-admission Comprehensive Examination: On 2023-06-04 (DAY1), arterial blood gas analysis showed pH of 7.37, PCO2 of 34.0 mmHg, PO2 of 78.0 mmHg under mask oxygenation, and an oxygen saturation of 95%. Emergency complete blood count and inflammatory markers showed a white blood cell count of 12.4×109/L, with a neutrophil percentage of 95.9% and lymphocyte percentage of 2.6%. The platelet count was 220×109/L, and high-sensitivity C-reactive protein (CRP) exceeded 370.0mg/L. Coagulation tests revealed a prothrombin time of 9.3 seconds, plasma fibrinogen of 9.22g/L, and D-dimer of 2.278µg/mL. Procalcitonin (PCT) and interleukin-6 (IL-6) levels were 9.58 ng/mL and 1391.1 pg/ml, respectively, while the nucleic acid test for the novel coronavirus returned negative. Chest and abdominal CT scans on the same day revealed pulmonary infection, with inflammation and partial consolidation in the upper and lower lobes of the right lung (Fig. 1).
Upon admission, the patient's evaluations included: a Sequential Organ Failure Assessment (SOFA score) of 8 points; a CURB-65 score for community-acquired pneumonia of 3 points; a Pneumonia Severity Index (PSI) of 149 points, classifying as class V ,with a predicted mortality rate of 27%; and a Venous Thromboembolism (VTE) score - Padua Prediction Score of 6 points, indicating a high risk.
Treatment: On the admission day (June 4, 2023), the patient, experiencing a reduction in oxygenation, was promptly intubated and placed on mechanical ventilation. Imipenem/cilastatin 0.5g every 8 hours combined with tigecycline 50mg every 12 hours was administered for anti-infection, along with enoxaparin 0.2 ml subcutaneously every 12 hours for anticoagulation, and treatments for expectoration and asthma relief. On June 7, 2023 (DAY 3), bronchoscopy was performed, and the lavage fluid was analyzed using mNGS at Zhejiang Shengting Medical Laboratory Co., Ltd., identifying a Chlamydia psittaci infection with 5434 sequence counts, with no viral RNA sequences detected the following day (June 8, 2023, DAY 4). Treatment was adjusted to moxifloxacin sodium chloride injection 0.4g daily with continued tigecycline 50mg every 12 hours for anti-infection, complemented by intermittent prone positioning ventilation and bronchoscopy suction among other supportive care measures. Subsequent treatment led to improvements in pulmonary function, enhanced oxygenation, and reduced inflammatory markers such as PCT and CRP. On June 12, 2023 (DAY 8), the patient reported concealed pain in the upper left abdomen with palpation tenderness but no muscle tension. Blood tests showed hemoglobin at 74 g/L, platelets at 60×109/L, fibrinogen at 0.64 g/L, and D-dimer at 35.682 µg/ml; an enhanced abdominal CT scan revealed Gerota's fascia effusion, splenic infarction, and abdominal pelvic effusion (Fig. 2).
Following discussions at a Multi-Disciplinary Treatment (MDT) meeting, the patient was diagnosed with severe Psittacosis pneumonia complicated by splenic infarction. Given the absence of splenic abscess or rupture and no need for surgical intervention, conservative medical management was employed. Enoxaparin injections were substituted with rivaroxaban 10mg administered nasogastrically once daily for anticoagulation, complemented by supportive treatments including transfusions of fibrinogen, platelets, red blood cells, plasma, and cryoprecipitate. Subsequent to these interventions, the patient's abdominal pain subsided, inflammatory markers diminished, and oxygenation levels increased. Mechanical ventilation was ceased on June 16, 2023 (DAY 12), and the patient was transitioned to a regular ward with high-flow nasal oxygen. Post-discharge imaging revealed (Fig. 3) substantial resolution of pulmonary inflammatory lesions and improvement in the spleen's low-density lesions compared to prior assessments. The therapeutic approach during the hospital stay, evolution of the patient's condition, and discharge follow-up findings are illustrated in Fig. 4.
This study received approval from the Ethics Committee of Haining People's Hospital [Approval number: (2023) Ethics Review No. 118], and informed consent was duly obtained.