A Rare Case of Spontaneous Empyema by Clostridium perfringens

Empyema caused by clostridial infections is rare especially in the absence of invasive thoracic procedures. We present the case of an 81-year-old man without a history of preceding trauma who presented with shortness of breath and nonproductive cough and grew Clostridium perfringens only in the pleural cavity. He was predisposed to the infection due to his swallowing dysfunction. He was treated with penicillin and chest tube placement for drainage and subsequently improved.


Introduction
Clostridial infections of the lung and pleura are uncommon [1,2]. ese infections are usually reported in the event of trauma, invasive percutaneous procedures of the pleural cavity, or chronic disease or aspiration [1,3,4]. Spontaneous cases of Clostridium perfringens in the absence of abovementioned risk factors are rare [1]. We report the case of an 81-year-old man with C. perfringens empyema.

Case Description
An 81-year-old man presented to the emergency department (ED) with shortness of breath and nonproductive cough. He denied fever, chills, or chest pain. He was afebrile with blood pressure 127/68 mmHg, pulse rate 63/min, and respiratory rate 22/min. e patient's saturation was 89% in room air which improved to 97% with 2L of oxygen. He had decreased breath sounds with crackles over the right lung eld. e remainder of the physical exam was unremarkable. e patient had been admitted 2 weeks before with lower extremity weakness which was thought to be secondary to deconditioning from a recent upper respiratory tract infection for which he was treated with amoxicillin by his primary care physician. At that time, he was discharged with provisions for physical therapy. e patient had a past medical history of paroxysmal atrial brillation on amiodarone but not on anticoagulation, hypertension, and chronic kidney disease stage III. He had a 20 pack-year smoking history and had quit 57 years ago.
On arrival, the patient's WBC count was 12,500/µl with 85.9% neutrophils. ABG showed pH of 7.496 with pCO 2 33.9 mmHg, pO 2 80.2 mmHg, and bicarbonate 26.4 meq/l. Chest X-ray revealed new, moderately extensive, multifocal right lung pneumonia with small associated parapneumonic e usion ( Figure 1). CT chest further detailed a right basilar opaci cation with right pleural e usion and small amount of pleural gas (Figure 2). e patient was started on IV vancomycin, piperacillin-tazobactam, and oral azithromycin in the ED. Azithromycin was discontinued a day later after recommendations from Infectious Disease. Blood, sputum, and pleural uid studies were ordered. oracocentesis showed pH 6.9, protein 4.6 g/dl (serum protein 5.7 g/dl; reference range: 6.4-8.9 g/dl), albumin 2.1 g/dl (serum albumin 2.2 g/dl), and lactate dehydrogenase (LDH) 4844 IU/L (serum LDH: 273 IU/L), suggestive of empyema. A 12 Fr chest tube was placed under CT guidance by interventional radiology which yielded foul-smelling, dark burgundy uid. Pleural uid culture was positive for pansensitive C. perfringens. Surprisingly, sputum culture grew Pseudomonas aeruginosa and Citrobacter koseri, both of which were sensitive to piperacillin-tazobactam. We did not order a quantitative culture to di erentiate between pulmonary colonization and infection. We also did not perform bronchoscopy to rule out any mass or foreign body associated with the empyema. IV vancomycin was discontinued. IV clindamycin was added but was later discontinued after stool was positive for Clostridium di cile. e patient was planned for a 4-week course of IV piperacillin-tazobactam. On day 8, the patient was noted to have right lower extremity swelling which led to the discovery of extensive DVT and submassive PE, which was treated with Eliquis. Due to bleeding risk, decortication was deferred and the patient was instead treated with intrapleural tPA and dornase alpha.
With further questioning during hospital stay, the patient mentioned that he had di culty swallowing food due to the sensation that something was stuck in his throat. He had resting tremor of the left hand and subtle cogwheeling of the right upper extremity. e swallowing function study was positive for aspiration. MRI brain to rule out any intracranial pathology was done which showed focal acute/subacute infarction. Echocardiogram with double bubble study revealed a patent foramen ovale. For this, cardiology advised anticoagulation with consideration for closure in the event of a stroke while on Eliquis. Neurology suspected that dysphagia was due to Parkinson's disease and recommended starting Sinemet in the near future. e patient was discharged to acute rehab with a chest tube to water seal. Chest CT done a month later showed improvement of the e usion with minimal drainage from the tube. e chest tube was removed. Repeat pleural uid cultures were negative for infection. e patient did not show any uid reaccumulation on subsequent imaging studies (Figures 1 and 2).

Discussion
Detection of pleuropulmonary infections with C. perfringens has improved with advances in sampling and culture methods [5]. Despite that, C. perfringens is rarely the cause of empyema [3]. Jackson et al. conducted a study for surveillance of invasive C. perfringens in 1 million residents in Alberta, Canada, but did not detect any case of C. perfringens-related empyema [6].
Clostridia are commonly found as commensals in the intestines and in soil [3,7]. ey can also colonize the skin especially with hospitalization [5]. Infection into the pleural space has been explained by various mechanisms. Entry of the infection can occur through open wounds or during invasive procedures like thoracocentesis, chest tube drainage, or surgery [3,5,[7][8][9]. Underlying lung pathology like   Case Reports in Infectious Diseases tuberculosis and pleural e usions and chronic diseases such as cirrhosis, diabetes, and malignancy increase predisposition [1,5]. Aspiration has been described as a possible source of infection, as clostridia have been isolated in the oral ora of hospitalized patients [5,8,9]. Mixed organisms are usually seen in these patients [5]. Hematogeneous seeding of C. perfringens has been reported after sigmoid biopsy and esophageal rupture [3,5]. Bashir et al. reported cases of necrotizing pneumonia complicating pulmonary embolus [4]. Our patient may have acquired C. perfringens during his recent hospitalization. With his swallowing dysfunction, he may have aspirated the organism. Surprisingly, anaerobic sputum cultures failed to detect C. perfringens. Hematogeneous seeding is a possibility in our case, but blood cultures were negative. Bashir et al. reported C. perfringens complicating pulmonary emboli, but they thought that these two entities were unrelated [4]. Although our patient had pulmonary embolus, it was absent when infection was rst detected. Kwan et al. reported C. perfringens empyema without pneumonia [3]. Our patient had pneumonia with parapneumonic e usion, but the organisms cultured were di erent. e pleural uid is classically malodorous, dark red to brown as in our patient [2]. Imaging shows air-uid levels with gas production which can be confused with herniation of the intestine into the thoracic cavity [2,5]. e mainstay of management is surgical drainage and antibiotics [2,3,8,9]. Penicillins are the rst-line choice [2]. Use of another antibiotic like clindamycin, metronidazole, or chloramphenicol is indicated only in cases of penicillin allergy [2,5]. Roberts et al. reported 100% susceptibility to penicillins (amoxicillin/clavulanic acid and piperacillin-tazobactam), cephalosporins (cefoxitin, cefotetan, and ceftriaxone), clindamycin, carbapenems (imipenem and meropenem), and metronidazole [10]. e role of antitoxins and hyperbaric oxygen therapy has not yet been established [2,3]

Conclusion
Prognosis for C. perfringens is good with appropriate treatment including pleural drainage and appropriate antianaerobic antibiotic therapy [9]. Clinicians must be aware of this etiology for pleural infections for prompt treatment.

Conflicts of Interest
e authors declare that they have no con icts of interest.