Descending Necrotizing Mediastinitis With Diffuse ST Elevation Mimicking Pericarditis: a Case Report

Descending Necrotizing Mediastinitis With Diffuse ST Elevation Mimicking Pericarditis: a Case Report

The Journal of Emergency Medicine, Vol. 47, No. 4, pp. 408–411, 2014 Copyright Ó 2014 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/...

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The Journal of Emergency Medicine, Vol. 47, No. 4, pp. 408–411, 2014 Copyright Ó 2014 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter

http://dx.doi.org/10.1016/j.jemermed.2014.05.014

Selected Topics: Critical Care DESCENDING NECROTIZING MEDIASTINITIS WITH DIFFUSE ST ELEVATION MIMICKING PERICARDITIS: A CASE REPORT Young Soon Cho, MD and Jae Hyung Choi, MD Department of Emergency Medicine, College of Medicine, Soonchunhyang University, Bucheon-si, Gyeonggi-do, Korea Reprint Address: Jae Hyung Choi, MD, Department of Emergency Medicine, College of Medicine, Soonchunhyang University, 1174, Jung-dong, Wonmi-gu, 1174, Bucheon-si, Gyeonggi-do 420-767, Korea

, Keywords—mediastinitis; elevation

, Abstract—Background: Descending necrotizing mediastinitis (DNM) is a potentially fatal disease that requires aggressive treatment, including mediastinal exploration. The inflammation associated with DNM may involve the heart, which produces acute changes in the electrocardiogram (ECG). As a result, the ECG may mimic pericarditis, causing some diagnostic confusion. Objectives: The objectives of this case report are to describe a case of DNM presenting electrocardiographically with pericarditis, and to discuss how to differentiate between benign viral pericarditis and DNM, and the management of these two diseases. Case Report: We present the case of a previously healthy 50-year-old man who presented to the Emergency Department for chest pain and presumed pericarditis. The patient presented with ST elevation on multiple leads on ECG, tenderness in the neck, widened mediastinum on the chest radiograph, and nonspecific laboratory test results. Echocardiography revealed normal ventricle function and the presence of mild pericardial effusion. The emergency physician performed contrast-enhanced neck computed tomography (CT) to rule out deep-neck infection. The CT scan showed marginal rim-enhancing abscesses in the retropharyngeal, bilateral submandibular, and anterior visceral spaces with extension into the thoracic cavity. Contrastenhanced chest CT was performed consecutively. The final diagnosis was deep-neck infection with DNM. The patient underwent mediastinoscopy-assisted drainage and neck fasciotomy twice and received 7 weeks of therapy with intravenous meropenem. Conclusion: The present case highlights the importance of considering a mediastinal cause for acute ECG changes. Ó 2014 Elsevier Inc.

pericarditis;

ST-segment

INTRODUCTION Descending necrotizing mediastinitis (DNM) originating from deep-neck infection is rapidly progressive, destructive, and fatal, and often requires surgical treatment. Despite current antibiotic therapy, advances in diagnostic and surgical techniques, and improvements in anesthetic and intensive care protocols, DNM remains a lifethreatening condition with mortality rates of up to 30% (1,2). Delayed diagnosis is one of the primary reasons for the high mortality rate of DNM, but early diagnosis of mediastinitis is often difficult because the early symptoms implicating mediastinal involvement are vague (3). Both mediastinitis and pericarditis may produce similar clinical images including ST-segment elevation on the electrocardiogram (ECG) (4–7). The present case highlights the importance of considering a mediastinal cause for acute ECG changes. CASE REPORT A 50-year-old man presented to the Emergency Department with low-grade fever, sore throat, cough, and chest pain for 1 week. He had visited an otolaryngologist 7 days

RECEIVED: 3 May 2013; FINAL SUBMISSION RECEIVED: 12 March 2014; ACCEPTED: 2 May 2014 408

The Importance of Considering a Mediastinal Cause for Acute ECG Change

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Figure 1. Initial electrocardiogram showing widespread ST-segment elevations and PR-segment depression with reciprocal changes in aVR and V1.

earlier; however, medications for acute pharyngotonsillitis failed to provide symptomatic relief. Progressive chest pain developed 2 days later. He was a nonsmoker and consumed alcohol occasionally. Physical examination revealed a blood pressure of 90/60 mm Hg, body temperature of 36.4 C, and tenderness and redness in the left side of the neck. The other examination results were normal. White blood cell count was 9240/mL with 90% neutrophils, and the platelet count was 65,000/mL. Both C-reactive protein levels and erythrocyte sedimentation rate were elevated at 45.16 mg/L (ref. 0.0–8.0 mg/L) and 94 mm/h (0–10 mm/h), respectively. Both blood urea nitrogen and creatinine levels were elevated at 62.8 mg/dL (ref. 8.0–20 mg/dL) and 1.6 mg/dL (ref. 0.6–1.3 mg/dL), respectively. Other laboratory test results were normal, including plasma levels of electrolytes, troponin, and creatine kinase-MB. The ECG (Figure 1) showed widespread ST-segment elevations and PR-segment depression with reciprocal changes in aVR and V1. Echocardiography revealed normal ventricle function and the presence of mild pericardial effusion. Chest radiograph (Figure 2) showed a widened mediastinum and bronchial wall thickening with nodular opacities in the lower basal lobe. Although the ECG findings were consistent with pericarditis, the patient’s clinical picture, including fever, hypotension, and neck erythema, were concerning for a suppurative cause. Accordingly, the physician performed a contrast-enhanced neck computed tomography (CT) scan to assess for deep-neck infection. The CT scan (Figure 3) showed marginal rim-enhancing abscesses in the retropharyngeal, bilateral submandibular, and anterior visceral spaces with extension into the thoracic cavity. Contrast-enhanced chest CT was performed consecutively. The chest CT scan (Figure 4) showed marginal rim-enhancing abscesses in the upper paratracheal area, prevascular space, subcarinal area, and both hilar regions with bilateral pleural fluid and atel-

ectasis in the lower basal lobe. The final diagnosis was deep-neck infection with DNM. In addition to intravenous antimicrobial agents, the patient received mediastinoscopy-assisted drainage and neck fasciotomy. The operative findings included swelling of the left neck, containing pus that communicated with the retropharyngeal abscess, as well as soft-tissue necrosis and loculated abscess in the mediastinum. The pus culture yielded Streptococcus anginosus. Severe sepsis persisted, and on the 7th day in the hospital, the patient received repeated mediastinoscopy-assisted drainage and decortications, which resulted in the improvement of his

Figure 2. Chest radiography at the time of arrival at the emergency department showing a widened mediastinum and bronchial wall thickening with nodular opacities in the lower basal lobe.

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Figure 3. Contrast-enhanced neck computed tomography scan showing marginal rim-enhancing abscess (arrow) in the retropharyngeal, bilateral submandibular, and anterior visceral spaces with extension to the thoracic cavity (arrow head). (A) Axial view, (B) coronal view, and (C) sagittal view.

condition. He received 7 weeks of therapy with intravenous meropenem. At the 6-month follow-up, the patient was healthy. DISCUSSION Acute pericarditis is an inflammation of the pericardium and typically has a good outcome. The cause of acute pericarditis in 90% of patients is either viral or unknown (4). In contrast, DNM is a bacterial infection involving the neck and mediastinum, and is a fatal disease with mortality rates of up to 30% (1,2). Accordingly, whereas acute pericarditis can be treated with nonsteroidal antiinflammatory drugs alone, DNM requires early diagnosis and aggressive treatment (1–4). However, both mediastinitis and pericarditis may produce similar clinical pictures, including clinical presentations and ECG patterns. Like DNM, the common presentation of acute pericarditis is retrosternal chest pain, which often radiates into the neck or back (4–7).

The classic ECG findings for acute pericarditis include diffuse ST-segment elevation in the precordial and limb leads, in more than one coronary artery territory, and PR-segment depression, which is the atrial counterpart of ST-segment elevation (6). In addition, mediastinitis results in bacterial perimyocarditis, which may also give rise to changes in the ECG (7). In the present case, the patient presented with an electrocardiographic picture of widespread ST elevation, vague symptoms, and nonspecific laboratory test results. In the absence of CT scans, it was very difficult to distinguish between mediastinitis and other pericardial diseases. These electrocardiographic changes were temporally matched to the presence of pus in the mediastinum and resolved rapidly once the pus was drained. DNM develops in 6.3% to 17% of deep-neck infections (5). This infection spreads along the fascial planes and spaces of the head and neck; the most frequent causes are odontogenic abscess and pharyngotonsillitis (8). The diagnosis of cervical infection is clinically obvious,

Figure 4. Contrast-enhanced chest computed tomography scan showing marginal rim-enhancing abscess (arrow) in the upper paratracheal area, prevascular space, subcarinal area, and both hilar regions with bilateral pleural fluid and atelectasis (arrow head) in the lower basal lobe. (A) Axial view, (B) coronal view.

The Importance of Considering a Mediastinal Cause for Acute ECG Change

whereas that of DNM is often difficult because the early symptoms implicating mediastinal involvement are vague. Therefore, the diagnosis of acute mediastinitis with conventional radiographic studies may be difficult. Radiographic examination of the neck and chest can reveal several features: widening of the retrovisceral space (with or without air-fluid level), anterior displacement of the tracheal air column, mediastinal emphysema, and widening of the superior mediastinal shadow. However, these signs often appear very late in the course of the disease (3). Early diagnosis can be made by cervicothoracic CT, which typically shows swelling and fluid collection with gas bubbles in the neck and mediastinum (1,3). Important therapies for DNM include early and aggressive medical and surgical treatments (2). Patients receiving combined cervical and thoracic drainage have better outcomes than those receiving less-extensive surgical approaches (1). In the present case, the patient presented with a widened mediastinum on the chest radiograph, sore throat, and tenderness in the neck. The diagnosis was ultimately made when a CT scan was obtained to assess for a deep neck infection. CONCLUSION The case highlights the importance of patient history, physical examination, and radiographic findings to differ-

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entiating between DNM and other more benign causes of pericarditis. Although awareness of ST- and PR-segment changes as other causes of chest pain is adequate, DNM can be fatal if there is a delay in diagnosis and initiation of definitive treatment. REFERENCES 1. Misthos P, Katsaragakis S, Kakaris S, Theodorou D, Skottis I. Descending necrotizing anterior mediastinitis: analysis of survival and surgical treatment modalities. J Oral Maxillofac Surg 2007;65: 635–9. 2. Roccia F, Pecorari GC, Oliaro A, et al. Ten years of descending necrotizing mediastinitis: management of 23 cases. J Oral Maxillofac Surg 2007;65:1716–24. 3. Marty-Ane CH, Berthet JP, Alric P, Pegis JD, Rouviere P, Mary H. Management of descending necrotizing mediastinitis: an aggressive treatment for an aggressive disease. Ann Thorac Surg 1999;68: 212–7. 4. Lange RA, Hillis LD. Clinical practice. Acute pericarditis. N Engl J Med 2004;351:2195–202. 5. Ishinaga H, Otsu K, Sakaida H, et al. Descending necrotizing mediastinitis from deep neck infection. Eur Arch Otorhinolaryngol 2013; 270:1463–6. 6. Wang K, Asinger RW, Marriott HJ. ST-segment elevation in conditions other than acute myocardial infarction. N Engl J Med 2003; 349:2128–35. 7. Catarino PA, Westaby S. Postcardiac surgery mediastinitis mimicking acute inferior myocardial infarction. J Card Surg 2000; 15:309–12. 8. Marioni G, Staffieri A, Parisi S, et al. Rational diagnostic and therapeutic management of deep neck infections: analysis of 233 consecutive cases. Ann Otol Rhinol Laryngol 2010;119:181–7.