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A Women in Her 50s With Recent Coronary Artery Bypass Grafting Presenting With Right-Sided Chest PainRight-Sided Chest Pain After Bypass Graft FREE TO VIEW

Muhammad Adrish, MD; Ariel L. Shiloh, MD
Author and Funding Information

From the Division of Critical Care Medicine, Department of Medicine, Albert Einstein College of Medicine, Jay B. Langner Critical Care Service, Montefiore Medical Center, Bronx, NY.

CORRESPONDENCE TO: Muhammad Adrish, MD, Division of Critical Care Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Critical Care Administration, 111 E 210th St, Bronx, NY 10467; e-mail: aadrish@hotmail.com


Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.


Chest. 2015;147(5):e171-e174. doi:10.1378/chest.14-0457
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Published online

A woman in her 50s with hypertension, diabetes mellitus, and coronary artery disease who underwent coronary artery bypass graft surgery 1 month prior was admitted to the hospital for right-sided chest pain of 1-day duration. The patient described the pain as sharp in nature, nonpleuritic, radiating to her right hand, and lasting for 2 to 3 min at a time. She denied cough, shortness of breath, diaphoresis, or palpitations but reported having fevers and chills 1 day prior to presentation. Her temperature was 38.7°C. Cardiac examination was normal except for mild tachycardia. No jugular venous distension was noted. The sternal incision site did not show erythema, swelling, or fluctuation, but chest wall tenderness was elicited along the right-side parasternal region of the second and third intercostal spaces. No sternal click was present. Laboratory results showed leukocytosis (17.9 × 103/μL) but otherwise normal electrolyte levels and renal function. Cardiac enzyme levels were normal, and no new ECG changes were noted. Chest radiography revealed no infiltrates, pulmonary edema, or effusions (Fig 1). Ceftriaxone was empirically initiated.

On hospital day 2 the patient’s blood and urine cultures grew group B streptococcus. Transthoracic echocardiogram demonstrated a mildly reduced left ventricular ejection fraction, regional wall motion abnormalities in the apical and septal regions, and mild to moderate mitral regurgitation. Given the recent cardiac surgery and positive blood cultures, endocarditis was suspected, and transesophageal echocardiography (TEE) was scheduled. On hospital day 3, a rapid response was activated for respiratory distress and hypotension just prior to the TEE. The patient was lethargic and in severe respiratory distress. Her BP was 85/45 mm Hg, and heart rate was 140 beats/min. She was promptly intubated and resuscitated. An ECG did not reveal acute changes.

The patient’s differential diagnosis included

  • • Septic shock due to endocarditis

  • • Septic shock due to deep surgical site infection

  • • Cardiogenic shock due to acute heart failure

  • • Cardiogenic shock due to acute valvular insufficiency

  • • Obstructive shock due to pulmonary embolism

The intensivist team performed bedside ultrasonography to determine the cause of shock.

Based on the information available from the patient’s presentation and ultrasonography (review case Video 1, Video 2, Video 3, Video 4), what is the diagnosis?

Sternal Video 1

Case Presentation

Sternal Video 2

Case Presentation

Sternal Video 3

Case Presentation

Sternal Video 4

Case Presentation

Diagnosis: Septic shock due to sternal wound site abscess

Sternal Videos 1-4

Discussion

Running Time: 06:14

Transthoracic echocardiogram performed at the time of the patient’s cardiovascular collapse was grossly unchanged from the day prior (Discussion Videos 1-4). Cardiac imaging was limited, and the endocardial borders were poorly visualized; the best view obtained, the apical four-chamber view, suggested a moderately reduced left ventricular function (with septal and apical hypokinesis). The right ventricular size and function were normal. There was no evidence of a pericardial effusion. The image quality limited valvular visualization, but wide-open mitral regurgitation and large vegetations were unlikely (Discussion Videos 1, 2). When imaging the sternal incision site and the previously noted tender parasternal region, the intensivist team discovered a nonpericardial, extracardiac fluid collection. The collection was visualized using a linear probe (5-10-MHz vascular probe), ideal for imaging superficial structures. Discussion video 3 shows views starting from the top of the midsternal area to approximately 4 cm distal to the suprasternal notch. A complex, exudative collection was seen 0.5 cm beneath the skin that was communicating inferiorly. Bilateral pleural imaging demonstrated lung sliding and an A-line pattern, ruling out pneumothorax and parenchymal lung disease.

Although it would be ideal to capture a more complete study (parasternal long and short, apical four-chamber, and subcostal views), studies can be limited, especially in severe shock states, because of body habitus, postoperative wounds or changes, and the inability to reposition patients during resuscitative efforts, all of which occurred with this patient. Additionally, except for the identification of wide-open valvular regurgitation, determination of valvular pathologies and grading valvular disorders are beyond the scope of goal-directed ultrasonography. Despite the limited views, cardiogenic shock secondary to depressed ventricular function, severe valvular insufficiency, or obstruction was unlikely.

Based on the ultrasonographic findings, the etiology of the patient’s septic shock was attributed to a sternal wound abscess. As a life-saving intervention, the cardiothoracic surgery team performed an emergent bedside incision and drained approximately 1 L of pus. Wound cultures also grew group B streptococcus, and antibiotics were deescalated as appropriate. The TEE showed a 0.5 cm vegetation on the posterior leaflet of the mitral valve. The patient underwent additional sternal wound debridement and washout in the operating room. Vasopressors were tapered, and the patient was extubated. She was ultimately discharged on long-term antibiotic therapy.

The sonographic presentation of fluids differs based on the protein or debris content present within. Transudative, or simple, fluid is anechoic and appears black on ultrasound imaging. In contrast, exudative, or complex, fluid demonstrates an echogenic component.1 The more protein or debris present in the fluid, the brighter or more reflective it appears on ultrasound. Typically, the debris settles, creating a gradient effect known as the hematocrit sign, where the fluid collection is anechoic toward the top and echogenic toward the bottom. This is often seen in the case of bleeding, where the proteinaceous and cellular components separate from plasma and settle at the lowest point. When cardiac and respiratory motion agitates debris, the echogenic components float and circulate in an otherwise anechoic space. This is known as the plankton sign, analogous to organisms drifting in a body of water.2

Sternal wound infection after coronary artery bypass graft surgery has an overall incidence of 1.7%. The most common isolated pathogen is Staphylococcus aureus followed by coagulase-negative Staphylococcus.3 Other pathogens, such as Propionibacterium, Acinetobacter, Enterobacter cloacae, Escherichia coli, and Klebsiella, have also been identified. There is a subset of patients who never grow a pathogen and are deemed to have noninfectious sternal dehiscence. Diagnosis is often clinical in nature, and definitive treatment consists of early antibiotics and wound exploration. Patients usually present with fever and leukocytosis along with signs of sternal wound dehiscence, suggesting deep sternal wound infection. Sternal nonunion can be identified by a sternal click on physical examination. CT scan of the chest is highly sensitive for diagnosis, and nuclear imaging can be of value in early presentations.4

In the present patient, a sternal wound infection and abscess was diagnosed with a bedside goal-directed ultrasound examination of a recent surgical site and incision. Ultrasonography is an excellent imaging modality for visualizing fluid collections. Pleural effusions, ascites, and superficial abscesses are readily visualized with bedside sonography.5,6 Ultrasound quantifies the amount of fluid, qualifies the type of fluid, and aids in guiding drainage when appropriate.

  • 1. The sonographic presentation of fluid collections varies based on the protein or debris content.

  • 2. Transudative fluid is anechoic and appears black when imaged.

  • 3. The hematocrit sign and plankton sign are indicative of an exudative fluid collection.

Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

Other contributions: CHEST worked with the authors to ensure that the Journal policies on patient consent to report information were met.

Additional information: To analyze this case with the videos, see the online version of this article.

Herth FJF, Becker HD. Transthoracic ultrasound. Respiration. 2003;70(1):87-94. [CrossRef] [PubMed]
 
Mayo PH, Doelken P. Pleural ultrasonography. Clin Chest Med. 2006;27(2):215-227. [CrossRef] [PubMed]
 
Ståhle E, Tammelin A, Bergström R, Hambreus A, Nyström SO, Hansson HE. Sternal wound complications—incidence, microbiology and risk factors. Eur J Cardiothorac Surg. 1997;11(6):1146-1153. [CrossRef] [PubMed]
 
Gur E, Stern D, Weiss J, et al. Clinical-radiological evaluation of poststernotomy wound infection. Plast Reconstr Surg. 1998;101(2):348-355. [CrossRef] [PubMed]
 
Bouhemad B, Zhang M, Lu Q, Rouby JJ. Clinical review: bedside lung ultrasound in critical care practice. Crit Care. 2007;11(1):205. [CrossRef] [PubMed]
 
Mayo PH, Goltz HR, Tafreshi M, Doelken P. Safety of ultrasound-guided thoracentesis in patients receiving mechanical ventilation. Chest. 2004;125(3):1059-1062. [CrossRef] [PubMed]
 

Tables

Sternal Video 1

Case Presentation

Sternal Video 2

Case Presentation

Sternal Video 3

Case Presentation

Sternal Video 4

Case Presentation

Sternal Videos 1-4

Discussion

Running Time: 06:14

References

Herth FJF, Becker HD. Transthoracic ultrasound. Respiration. 2003;70(1):87-94. [CrossRef] [PubMed]
 
Mayo PH, Doelken P. Pleural ultrasonography. Clin Chest Med. 2006;27(2):215-227. [CrossRef] [PubMed]
 
Ståhle E, Tammelin A, Bergström R, Hambreus A, Nyström SO, Hansson HE. Sternal wound complications—incidence, microbiology and risk factors. Eur J Cardiothorac Surg. 1997;11(6):1146-1153. [CrossRef] [PubMed]
 
Gur E, Stern D, Weiss J, et al. Clinical-radiological evaluation of poststernotomy wound infection. Plast Reconstr Surg. 1998;101(2):348-355. [CrossRef] [PubMed]
 
Bouhemad B, Zhang M, Lu Q, Rouby JJ. Clinical review: bedside lung ultrasound in critical care practice. Crit Care. 2007;11(1):205. [CrossRef] [PubMed]
 
Mayo PH, Goltz HR, Tafreshi M, Doelken P. Safety of ultrasound-guided thoracentesis in patients receiving mechanical ventilation. Chest. 2004;125(3):1059-1062. [CrossRef] [PubMed]
 
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