Mediastinitis

Educational Objectives

Educational Objectives

The goal of this program is to improve the surgical management of conditions of the thoracic region. After hearing and assimilating this program, the clinician will be better able to diagnose and treat mediastinitis.

Summary

Definition: inflammation or infection of mediastinum; origin of infection (neck or chest) must be determined

Diagnosis: sudden onset of refractory hypotension or difficulty in ventilation; may present with only tachycardia and tachypnea but can rapidly progress to vascular and pulmonary failure; pain retrosternal or radicular; may radiate to back (from posterior mediastinum) or to neck (from superior mediastinum); consider in patients who do poorly after neck, oral, mediastinal, or esophageal surgery, or with any penetrating trauma

Classification: superior mediastinitis — usually caused by direct extension from neck or anterior mediastinum (surgery of sternum, eg, cardiac surgery, anterior stab wounds); posterior mediastinitis — usually due to esophageal perforation (iatrogenic, Boerhaave) or penetrating trauma to spine or back; middle mediastinitis — usually caused by pericarditis or myocarditis

Presentation: patients may have crepitance in neck or anterior chest; Hamman sign — “crunching” sound heard during systole on auscultation of anterior chest; tachycardia, supraventricular tachyarrhythmias, and decrease in pulmonary compliance seen with increasing pressure and edema in mediastinum; refractory hypotension and vascular collapse follow (patients may develop cardiac arrest or inability to be resuscitated with fluids and pressors); tracheal deviation and venous extension in neck often seen in patients who do not arrest; refractory shock and edema of airway common and serious signs

Case example 1 (superior mediastinitis): patient with history of diabetes and smoking; received 2 courses of radiation therapy (RT) for cancer of larynx and developed osteonecrosis and erosion of tracheostomy into manubrium; purulence found in anterior neck and posterior mediastinum; risk for erosion increases when tracheostomy tubes placed inferiorly, or in wide or low radiation fields; obesity and kyphosis (patient leaning forward) associated with erosion into manubrium; internal portion of tube may erode posteriorly into esophagus; leaning backward (eg, due to neuromuscular disease) increases risk for anterior and superior erosion; other risk factors for osteomyelitis include diabetes, steroids, and chronic obstructive pulmonary disease; options for treatment — systemic therapy with antibiotics for maintenance (does not cure ongoing infection); consider palliative RT if patient not candidate for surgery; surgical debridement standard of care; if possible, remove tracheostomy; give 12 to 16 wk of intravenous antibiotics; cardiovascular compromise uncommon; debride necrotic tissue and bring vascularized tissue into area; no-tension closure needed due to constant movement of neck (open wound with vacuum-assisted dressing most common); omentum harvested to cover large defect after manubrium removed; use of vascularized tissue results in high short-term morbidity but low mortality

Case example 2 (anterior mediastinitis): patient with history of severe myasthenia gravis (treated with immunosuppression) presented 3 wk after thymectomy; presented with small dehiscence of superior portion of incision; purulent drainage noted; risks for osteomyelitis — nonunion of sternum after surgery; non-midline sternotomy; vascular disease; diabetes; osteoporosis (proper apposition of sternotomy more difficult); RT; chemotherapy; immunosuppression; treatment — long-term antibiotics for maintenance; debride and revascularize area with pectoralis muscle or omentum (tongue of omentum attached to inferior neck in this patient); compartment syndrome may develop, which requires increased pressors and ventilation postoperatively, and repeat surgery

Case example 3 (posterior mediastinitis): has highest mortality risk; patient presented with Boerhaave syndrome (retching and hematemesis), pain, tachypnea, tachycardia, and crepitance in neck; profound mediastinitis seen on imaging; esophageal perforation diagnosed; rapid necrosis of entire posterior mediastinum can develop; presence of edema similar to third-degree burn; massive amounts of fluids and pressors required due to loss of regulatory mechanisms; treatment — use of vascularized pedicle of intercostal muscle, and wide drainage; dissect all tissue planes of mediastinum to decompress; administer antibiotics and pressors (avoid using dopamine due to arrhythmogenic properties); use feeding tube if esophagus perforated; use colloid fluids and blood products (similar to patients with burns)

Case example 4 (middle mediastinitis): developed after total parenteral nutrition started in patient who had central line pushed through blood vessel into superior mediastinum; treated with decompression of blood vessel and puncture repaired; these patients often develop chronic restrictive defects of blood vessels and pericardium; decompress with pericardiectomy for palliation (morbidity generally high); use GI and pulmonary stenting only for palliation due to high risk for erosion; treatment includes long-term nonsteroidal anti-inflammatory agents and immunotherapy; patients committed to life-long steroid therapy if positron emission tomography indicates avid disease

Readings

Suggested Reading

Adson AW, Coffey JR: Cervical rib: a method of anterior approach for relief of symptoms by division of the scalenus anticus. Ann Surg 85:839, 1927; Athanassiadi KA: Infections of the mediastinum. Thorac Surg Clin 19:37, 2009; Bloom JD et al: Factors predicting endoscopic exposure of Zenker’s diverticulum. Ann Otol Rhinol Laryngol 119: 738, 2010; Boisevert RD et al: Bilateral Killian-Jamieson diverticula: a case report and literature review. Can J Gastroenterol 24:173, 2010; Brace M et al: Endoscopic stapling versus external transcervical approach for the treatment of Zenker diverticulum. J Otolaryngol Head Neck Surg 39:102, 2010; Chang DC et al: Reported in-hospital complications following rib resections for neurogenic thoracic outlet syndrome. Ann Vasc Surg 21:564, 2007; Collard JM et al: Endoscopic stapling technique of esophagodiverticulostomy for Zenker’s diverticulum. Ann Thorac Surg 56:573, 1993; Cowan KN et al: Vacuum-assisted wound closure of deep sternal infections in high-risk patients after cardiac surgery. Ann Thorac Surg 80: 2205, 2005; Dale WA: Thoracic outlet compression syndrome. Arch Surg 117:1437, 1982; Degeorges R et al: Thoracic outlet syndrome surgery: long-term functional results. Ann Vasc Surg 18:558, 2004; Gutschow CA et al: Management of pharyngoesophageal (Zenker’s) diverticulum: which technique? Ann Thorac Surg 74:1677, 2002; Hannan SA, Alusi G: Images in clinical medicine. Zenker’s diverticulum. N Eng J Med 354:e24, 2008; Mackinnon SE, Novak CB: Thoracic Outlet Syndrome. Curr Prob Surg 39: 1070, 2002; Molina JE: Reoperations after failed transaxillary first rib resection to treat Paget-Schroetter syndrome patients. Ann Thorac Surg 91:1717, 2011; Redenbach DM, Nelems B: A comparative study of structures comprising the thoracic outlet in 250 human cadavers and 72 surgical cases of thoracic outlet syndrome. Eur J Cardiothorac Surg 13:353, 1998; Roos DB: Transaxillary approach for first rib resection to relieve thoracic outlet syndrome. Ann Surg 163:354, 1966; Schimmer C et al: Management of poststernotomy mediastinitis: experience and results of different therapy modalities. Thorac Cardiovasc Surg 56:200, 2008.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, members of the faculty and planning committee reported nothing to disclose.

Acknowledgements

38th Annual Toronto Thoracic Surgery Refresher Course, held June 8-9, 2012, in Toronto, ON.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

GS600803

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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