Retropharyngeal Abscess Complicated by Mediastinitis in Infants.

INTRODUCTION: Most paediatric upper respiratory infections are virally mediated and result in self-limiting reactive lymphadenopathy. In children younger than 5 years, retropharyngeal lymph nodes may give rise to deep neck space infections in this potential space. Retropharyngeal infections are rare after 5 years because lymph nodes undergo atrophy. METHODS: We present a series of 6 cases of paediatric retropharyngeal abscesses (RPA) complicated by mediastinitis, managed at a tertiary hospital over a 4-year period. RESULTS: All our cases presented with fever, difficulty feeding, and neck swelling. The age range was 11 weeks-11 months, and all tested negative for human immunodeficiency virus. The diagnosis and complications were confirmed on computed tomography (CT) scan. The CT scans consistently revealed RPA with varying degrees of deep neck space and mediastinal extension. All children were promptly taken to theatre for source control. Two were extubated successfully immediately after surgery, and the other 4 were extubated in the paediatric intensive care unit, with the longest duration of intubation being 3 days. Methicillin-sensitive Staphylococcus aureus (MSSA) was cultured in all 6 cases. CONCLUSION: Management of these cases may be challenging, and young children with RPA require close care and airway monitoring. CT or magnetic resonance imaging is essential to delineate the extent of infection. Surgical drainage should be performed when there is a large abscess, a complication occurs, or an inadequate response in 24-48 h to medical management.

Post-cardiac surgery fungal mediastinitis: clinical features, pathogens and outcome.

OBJECTIVES: The occurrence of mediastinitis after cardiac surgery remains a rare and severe complication associated with poor outcomes. Whereas bacterial mediastinitis have been largely described, little is known about their fungal etiologies. We report incidence, characteristics and outcome of post-cardiac surgery fungal mediastinitis. METHODS: Multicenter retrospective study among 10 intensive care units (ICU) in France and Belgium of proven cases of fungal mediastinitis after cardiac surgery (2009-2019). RESULTS: Among 73,688 cardiac surgery procedures, 40 patients developed fungal mediastinitis. Five were supported with left ventricular assist device and five with veno-arterial extracorporeal membrane oxygenation before initial surgery. Twelve patients received prior heart transplantation. Interval between initial surgery and mediastinitis was 38 [17-61] days. Only half of the patients showed local signs of infection. Septic shock was uncommon at diagnosis (12.5%). Forty-three fungal strains were identified: Candida spp. (34 patients), Trichosporon spp. (5 patients) and Aspergillus spp. (4 patients). Hospital mortality was 58%. Survivors were younger (59 [43-65] vs. 65 [61-73] yo; p = 0.013), had lower body mass index (24 [20-26] vs. 30 [24-32] kg/m2; p = 0.028) and lower Simplified Acute Physiology Score II score at ICU admission (37 [28-40] vs. 54 [34-61]; p = 0.012). CONCLUSION: Fungal mediastinitis is a very rare complication after cardiac surgery, associated with a high mortality rate. This entity should be suspected in patients with a smoldering infectious postoperative course, especially those supported with short- or long-term invasive cardiac support devices, or following heart transplantation.

Routine Mediastinal Drainage Fluid Culture for Early Diagnosis of Poststernotomy Mediastinitis.

BACKGROUND: Early diagnosis of poststernotomy mediastinitis (PSM) is challenging. Since 2016, we have routinely performed mediastinal drainage fluid culture (MDFC) in patients undergoing sternotomy. This study aimed to determine the utility of MDFC for early diagnosis of PSM. METHODS: Between November 2016 and April 2020, we conducted MDFC in 1,012 patients on the third postoperative day and prospectively observed for PSM occurrence for 3 months. If bacteria were identified, additional MDFC or blood culture was performed to reduce the possibility of false positives. Based on MDFC results, the decision for early treatment for PSM was at the attending physician's discretion. RESULTS: Bacteria were identified in MDFC of 29 patients, eight of whom subsequently developed PSM. Among 983 patients with negative MDFC, only 15 developed PSM. In multivariate analysis, previous sternotomy history and positive MDFC were predictors of PSM. Positive MDFC was regarded as true positive if (1) PSM occurred subsequently, and/or (2) the same bacteria were identified in additional MDFC/blood culture. Non-occurrence of PSM in the absence of antibiotic treatment was regarded as false-positive MDFC. The sensitivity, specificity, and positive and negative predictive values of routine MDFC for diagnosis of mediastinal infection were 46.4, 99.0, 56.5, and 98.5%, respectively. When categorizing cases with positive MDFC based on the identified bacteria, the positive predictive value was highest (76.9%) when Staphylococci were identified. CONCLUSION: Routine MDFC after sternotomy can facilitate early diagnosis of PSM. Early treatment for PSM may be indicated in patients in whom Staphylococci are identified in the MDFC.

Spontaneous community-acquired PVL-producing Staphylococcus aureus mediastinitis in an immunocompetent adult - a case report.

BACKGROUND: Mediastinitis caused by hematogenous spread of an infection is rare. We report the first known case of community-acquired mediastinitis from hematogenous origin in an immunocompetent adult. This rare invasive infection was due to Panton-Valentine Leucocidin-producing (PVL+) methicillin-susceptible Staphylococcus aureus (MSSA). CASE PRESENTATION: A 22-year-old obese man without other medical history was hospitalized for febrile precordial chest pain. He reported a cutaneous back abscess 3 weeks before. CT-scan was consistent with mediastinitis and blood cultures grew for a PVL+ MSSA. Intravenous clindamycin (600 mg t.i.d) and cloxacillin (2 g q.i.d.), secondary changed for fosfomycin (4 g q.i.d.) because of a related toxidermia, was administered. Surgical drainage was performed and confirmed the presence of a mediastinal abscess associated with a fistula between the mediastinum and right pleural space. All local bacteriological samples also grew for PVL+ MSSA. In addition to clindamycin, intravenous fosfomycin was switched to trimethoprim-sulfamethoxazole after 4 weeks for a total of 10 weeks of antibiotics. CONCLUSIONS: We present the first community-acquired mediastinitis of hematogenous origin with PVL+ MSSA. Clinical evolution was favorable after surgical drainage and 10 weeks of antibiotics. The specific virulence of MSSA PVL+ strains played presumably a key role in this rare invasive clinical presentation.

A Technique for 360-Degree Rigid Sternal Fixation with Sternal Plates and Wire Cerclage.

Sternal instability after cardiac surgery can lead to poor bony healing, as well as deep sternal wound infections and mediastinitis. Rigid plate fixation is associated with greater stability and fewer complications compared with wire cerclage, however, rigid plate fixation alone lacks posterior stability of the sternum and may be less effective in morbidly obese or osteoporotic patients. This article describes a surgical technique of combined rigid plate fixation and wire cerclage that provides 360-degree stabilization for sternotomies in high-risk patients. We employed this technique in 40 patients with no incidence of deep sternal wound infection.

Descending necrotizing mediastinitis caused by Streptococcus constellatus in an immunocompetent patient: case report and review of the literature.

Descending necrotizing mediastinitis is a severe infection of the mediastinum. This syndrome manifests as fever and chest pain following cough and sputum production. A 49-year-old woman presented with fever and a 14-day history of pneumonia. CT showed mediastinal abscesses with a giant calcified mediastinal lymph node (21 × 18 mm) and pneumonia. Bronchoscopy by EBUS-TBNA under general anesthesia was performed. The pathogen found in the puncture culture was Streptococcus constellatus, and antibiotics (mezlocillin/sulbactam 3.375 IVGTT q8h) was administered. A proximal right main bronchial neoplasm, suspected lung cancer, was found and conformed to inflammatory granuloma. A total of 22 months post-discharge the patient was clinically stable. We also conducted a review of the literature for all Streptococcus constellatus descending necrotizing mediastinitis infections between 2011 and 2017.

Mediastinal tissue friability-An unreported complication from Mycobacterium chimaera infection post-cardiac surgery.

Mycobacterium chimaera can cause disseminated infection following cardiac surgery with cardiopulmonary bypass and contaminated heater-cooler devices. We discuss a 41-year-old man with a disseminated M. chimaera infection following surgery for a type A aortic dissection. His presentation included cachexia and dorsalgia with a work-up revealing vertebral osteomyelitis with an epidural abscess, bone marrow, and pulmonary infiltration, and fluid collection around his aortic graft. He received 1 month of antibiotics before the explantation of infected foreign material, mediastinal debridement, and aortic reconstruction. Complications included septic shock, respiratory and renal failure, mediastinitis, and four distal aortic anastomotic dehiscences from friable tissue and persistent infection.

Contained rupture of right ventricular outflow tract after Rastelli-type operation.

This report describes a 3-year-old infant with post-operative mediastinitis complicated by a contained rupture of the right ventricle. A contained rupture is recognised as the huge pulsating prominence of the anterior chest wall. CT confirmed blood communication between the right ventricular outflow tract and the cavity surrounded by the pectoral major musculocutaneous flap. This is a significant case in which severe adhesion between the right ventricle and the musculocutaneous flap could maintain her stable haemodynamics with a pulsating prominence.

Catheter based treatments for fibrosing mediastinitis.

Fibrosing mediastinitis is a rare, often debilitating and potentially lethal disease characterized by an exuberant fibroinflammatory response within the mediastinum. Patients typically present with insidious symptoms related to compression of adjacent structures including the esophagus, heart, airways, and cardiac vessels. Fibrosing mediastinitis is most often triggered by Histoplasmosis infection; however, antifungal and anti-inflammatory therapies are largely ineffective. While structural interventions aimed at alleviating obstruction can provide significant palliation, surgical interventions are challenging with high mortality and clinical experience with percutaneous interventions is limited. Here, we will review the presentation, natural history, and treatment of fibrosing mediastinitis, placing particular emphasis on catheter-based therapies.

Concordance between superficial swab and deep sampling in post-sternotomy mediastinitis: Single center experience.

OBJECTIVES: Deep sampling (DS) is the gold standard for microbiological diagnosis of post-sternotomy mediastinitis (PSM), however superficial swab (SS) are frequently performed in some centers and antibiotherapy initiated base on their results. We analysed the concordance between superficial swab and deep sampling in PSM. MATERIALS AND METHODS: We analysed retrospectively patients with a PSM between 2010 and 2014 at Saint-Luc University hospital (Belgium). We considered that there was a concordance between SS and DS when the same microorganism was found in the two sampling method in each patient. Patients were stratified in six groups according to microbiology results as Staphylococcus Aureus (SA) sensitive or resistant, coagulase negative Staphylococcus (CoNS), Gram negative bacilli (GNB), other Gram positive bacteria (GPB) and fungi. RESULTS: Thirty-six patients were included. Twenty-five men (69%) and a mean age of 66 years old. The overall concordance between SS and DS was 57%. SA and GNB showed high concordance (100% and 85.7% respectively). For the other groups the concordance was low. The sensitivity and specificity of SS was 97% and 33% respectively. The PPV and NPV of superficial swab was 96% and 50% respectively. CONCLUSION: Microbiological results from SS, even with flocked swabs, except for SA and GNB have low concordance with those obtained from deep sampling. Our data confirm that in PSM, deep sampling is the gold standard for microbiological assessment.

A case of Mycobacterium chelonae mediastinitis and acute humoral rejection after heart transplantation.

Mediastinitis is one of the life-threating complications that can occur after cardiac surgery. However, to the best of our knowledge, there has been no report of mediastinitis caused by Mycobacterium chelonae, which is one of the rapidly growing nontuberculous mycobacteria species. As far as we know, our case is the first case describing the curative management for mediastinitis caused by M. chelonae after heart transplantation.

Mediastinitis as complication of odontogenic infection: A case report.

Odontogenic infections are one of the most common dental problems, which affect 80%-90% of the population. Untreated odontogenic infections can cause life-threatening complications such as necrotizing fasciitis, descending necrotizing mediastinitis, internal jugular vein thrombosis, cavernous sinus thrombosis, carotid artery pseudoaneurysm or rupture, and systemic inflammatory response syndrome. This report aims to present a mediastinitis case, in a 22-year-old healthy male patient, which originated from an odontogenic infection. The patient was hospitalized because of worsening general health status, despite the antibiotherapy. Computed tomography (CT) scan revealed that periapical abscess was spreading to the mediastinum through retropharyngeal space. The patient was successfully treated by IV antibiotherapy, transcervical drainage, and extraction of tooth.

Exceptional association of two species of bacteria causing mediastinitis: Haemophilus influenzae (H. influenzae) and Aggregatibacter aphrophilus (A. aphrophilus).

BACKGROUND: Post cardiac surgery mediastinitis is the major infectious complication, despite the development of surgical techniques and the application of strict preventive measures. The Haemophilus influenzae mediastinitis is very rare. The mediastinitis caused by the association between Haemophilus influenzae and Aggregatibacter aphrophilus has never been described to our knowledge. CASE PRESENTATION: We report the case of an exceptional combination of Haemophilus influenzae and Aggregatibacter aphrophilus in a patient operated for single bypass which is complicated by mediastinitis the 10th day after the surgical act. CONCLUSION: The conclusion to be drawn from this work is to think in unusual seeds in case of mediastinitis post cardiac surgery for the elaboration of recommendations for antibiotic prophylaxis.

Successful heart transplantation in patients with total artificial heart infections.

BACKGROUND: Data are limited on clinical outcomes in patients awaiting heart transplant (HT) with total artificial heart (TAH) infections. METHODS: We retrospectively reviewed all TAH recipients at our center. TAH infection was classified as definite if a microorganism was isolated in cultures from the exit site or deep tissues around the TAH; as probable in patients without surgical or microbiologic evidence of infection but no other explanation for persistent or recurrent bloodstream infection (BSI); or possible in patients with clinical suspicion and radiographic findings suggestive of TAH infection, but without surgical intervention or microbiologic evidence. RESULTS: From 2012 to 2015, a total of 13 patients received a TAH, with a median age at implantation of 52 years (range: 28-60). TAH infection occurred in nine patients (seven definite, one probable, one possible) a median of 41 days after implant (range: 17-475). The majority of TAH infections were caused by Staphylococcus species. Seven of nine patients underwent HT (four had pre-HT mediastinal washout, and five had positive HT operative cultures). Three patients had an active BSI caused by the same pathogen causing TAH infection at the time of HT, with one developing a post-HT BSI with the same bacteria. No patient developed post-HT surgical site infection caused by the TAH infection pathogen. No deaths among HT recipients were attributed to infection. CONCLUSION: TAH infection is frequently associated with BSI and mediastinitis and Staphylococcus was the most common pathogen. A multimodal approach of appropriate pre- and post-HT antimicrobial therapy, surgical drainage, and heart transplantation with radical mediastinal debridement was successful in curing infection.

Mediastinitis superinfected by Achromobacter xylosoxidans. A case report.

We describe an extremely rare case of mediastinitis superinfected by emerging Achromobacter xylosoxidans. After mitral and aortic valves replacement, the patient first developed a Staphylococcus aureus mediastinitis, and five days after starting adapted antibiotic therapy, superficial pus analysis revealed the presence of Achromobacter xylosoxidans. This superinfection was considered superficial and focus was made on Staphylococcus aureus mediastinitis. Three weeks later, no more Staphylococcus aureus was found in pus samples and the sepsis seemed under control. Unfortunately, blood cultures were again positive for Achromobacter xylosoxidans three weeks later and the patient died from septic shock.

Group C strep mediastinitis.

This case is significant to the practice of emergency medicine because it represents the development of an uncommon and potentially fatal mediastinal infection from a commonly encountered and appropriately treated community respiratory pathogen. Most published reports on mediastinitis are those that are status-post cardiothoracic surgery. In our report, we discuss a case of a healthy, young individual who developed this morbid entity from extension of a simple respiratory infection where Group C Streptococcus has been isolated as the causative organism, which to our knowledge has not been previously reported. Further, this report outlines how a community acquired pneumonia progressed to a life threatening illness despite proper initial treatment per local and national guidelines.

Risk Factors Affecting the Prognosis of Descending Necrotizing Mediastinitis From Odontogenic Infection.

PURPOSE: Descending necrotizing mediastinitis (DNM) is a serious complication of head and neck infections and has an excessively high mortality rate owing to the lack of understanding of DNM. We assessed the clinical characteristics, diagnosis, treatment, and outcomes of odontogenic DNM and evaluated the risk factors affecting the prognosis of DNM to provide an up-to-date overview for clinical practice. MATERIALS AND METHODS: We performed a retrospective cohort study, enrolling a sample of patients with DNM due to odontogenic infection who had been referred from January 2013 to December 2016. The patients were classified into surviving and deceased groups. The primary predictors in the present study were the presence of multiple comorbidities, complications, demographic data (age, gender), laboratory tests (white blood cell count, percentage of neutrophils), and time (duration before diagnosis, length of hospital stay). The primary outcome variable was the patient outcome (dead or alive). The continuous variables were evaluated using Student's t test or the t test, and the categorical and binary variables were compared using the χ2 test or Fisher exact test. RESULTS: A total of 81 patients (68 men, 13 women; median age of 57.2 ± 12.2 years) were included. The mortality was 4.9%. The most frequent cause of DNM was periapical periodontitis (66.7%). The lower posterior molars were involved in 39.5% of the cases. Treatment consisted of antibiotic therapy, aggressive transcervical mediastinal drainage (n = 74), and thoracotomy (n = 7). The associated risk factors for mortality were complications (P < .005) and severe sepsis or septic shock (P < .001) on bivariate analysis. CONCLUSIONS: Septic shock and complications were the risk factors that correlated with a poor prognosis. A timely diagnosis and use of aggressive mediastinal drainage are fundamental to reducing the incidence of complications and the development of septic shock in odontogenic DNM patients.

Low antibodies titer and serological cross-reaction between Coxiella burnetii and Legionella pneumophila challenge the diagnosis of mediastinitis, an emerging Q fever clinical entity.

BACKGROUND: Coxiella burnetii is an intracellular and fastidious bacterium responsible of acute and persistent Q fever infection. Endocarditis and vascular infections are the most common serious complications of acute Q fever. CASE REPORT: We report the case of a 63-year-old man that presented a mediastinitis associated with a prosthetic vascular infection. Serological cross-reaction was observed between Coxiella burnetii, the agent of Q fever, and Legionella pneumophila with higher antibodies titer for L. pneumophila (IgG = 1:512) than for C. burnetii (phase I IgG = 1:400). We performed western blot with cross-adsorption that supports the diagnosis of C. burnetii infection. Two weeks later, a positive qPCR and culture for C. burnetii on swab taken from the mediastinal cutaneous fistula confirmed the definitive microbiological diagnosis of Q fever mediastinitis. CONCLUSION: Cross-reactivity between C. burnetii and Legionella spp. has long been known and should be considered in patients with persistent infections. It is important to establish the definite diagnosis because the antibiotic treatment regimens and duration are significantly different. To the best of our knowledge, we reported here the first case of mediastinitis associated to C. burnetii and we diagnosed this persistent infection despite low anti-C. burnetii phase I IgG levels.

Risk factors for excessively prolonged meropenem use in the intensive care setting: a case-contol study.

BACKGROUND: Inappropriate use of broad-spectrum antimicrobials affects adversely both the individual patient and the general public. The aim of the study was to identify patients at risk for excessively prolonged carbapenem treatment in the ICU as a target for antimicrobial stewardship interventions. METHODS: Case-control study in a network of 11 ICUs of a university hospital. Patients with uninterrupted meropenem therapy (MT) > 4 weeks were compared to controls. Controls were defined as patients who stayed on the ICU > 4 weeks and received meropenem for ≤ 2 weeks. Associations between case-control status and potential risk factors were determined in a multivariate logistic regression model. RESULTS: Between 1st of January 2013 and 31st of December 2015, we identified 36 patients with uninterrupted MT > 4 weeks. Patients with prolonged MT were more likely to be surgical patients (72.2% of cases vs. 31.5% of controls; p ≤ 0.001) with peritonitis being the most common infection (n = 16, 44.4%). In the multivariate logistic regression model colonization with multidrug-resistant (MDR) Gram-negative bacteria (OR 7.52; 95% CI 1.88-30.14, p = 0.004) and the type of infection (peritonitis vs. pneumonia: OR 16.96, 95% CI 2.95-97.49) were associated with prolonged MT. CONCLUSION: Surgical patients with peritonitis and patients with known colonization with MDR Gram-negative bacteria are at risk for excessively prolonged carbapenem therapy and represent an important target population for antimicrobial stewardship interventions.

A case of descending mediastinitis caused by Streptococcus pyogenes harboring genotype emm25 and sequence type 660.

Descending mediastinitis caused by Streptococcus pyogenes (group A streptococcus, GAS) is rare among cases of invasive GAS infection. In this report, we describe a case of a cervical abscess and secondary descending mediastinitis in a previously healthy 39-year-old Japanese man. The patient presented with a 2-week history of a sore throat, and subsequently developed an abscess and descending mediastinitis. We treated the cervical abscess using ampicillin/sulbactam and drainage, and GAS was subsequently isolated in two blood cultures from the patient's admission. Microbiological analyses revealed that the isolate harbored genotype emm25 and sequence type (ST) 660. This strain was susceptible to erythromycin (minimum inhibitory concentration [MIC]: ≤0.12 µg/mL), resistant to minocycline (MIC: >4 µg/mL), and possessed the tet(M) determinant. Although we have reviewed the literature regarding the clinical and microbiological characteristics of descending mediastinitis cause by GAS, little is known regarding epidemiological and clinical characteristics of emm25/ST660 GAS. Furthermore, to best of our knowledge, this is the first reported case of descending mediastinitis caused by emm25/ST660 GAS. Therefore, physicians should be aware of case with a cervical abscess and secondary descending mediastinitis caused by GAS infection, even if the patient is immunocompetent.