Computed tomography in diagnosing retropharyngeal abscess in children

A Near Miss of a Retropharyngeal Abscess with MRSA in a 5-Week-Old Boy Due to an Unusual Presentation

A retropharyngeal abscess (RPA) in early childhood is not uncommon due to at-risk lymph nodes in this deep neck space and is typified by fever, odynophagia, and a constellation of respiratory manifestations. However, RPA is exceedingly rare in the neonatal subpopulation and not part of the usual differential diagnosis algorithm in this age range. Herein, we present a unique case of a previously healthy 5-week-old male infant with protracted "congestion" and difficulty in oral feeding, whose clinical course is confounded by intermittent, positional bradycardia and subsequent apnea. He was eventually diagnosed with a methicillin-resistant Staphylococcus aureus (MRSA) RPA, leading to concurrent vascular and airways compromise in the form of baroreceptor-mediated bradycardia from mass-effect carotid body compression. This clinical case is an important reminder that any infant with positional vital sign changes should prompt urgent and thorough investigation for extraordinary and otherwise uncommon pathophysiologic states. The case also highlights the power of multidisciplinary collaboration across multiple specialties and parental advocacy in unifying a diagnosis for rare pediatric illnesses.

Diagnostic accuracy of contrast-enhanced CT for neck abscesses: A systematic review and meta-analysis of positive predictive value

OBJECTIVES

To review the diagnostic accuracy of contrast-enhanced computed tomography (CT) in differentiating abscesses from cellulitis in patients with neck infections, using surgical findings as the reference standard.

MATERIALS AND METHODS

Previous studies in the last 32 years were searched from PubMed and Embase. Because of partial verification bias (only positive abscess findings are usually verified surgically), sensitivity and specificity estimates are unreliable, and we focused on positive predictive value (PPV). For all studies, PPV was calculated as the proportion of true positives out of all positives on imaging. To estimate pooled PPV, we used both the median with an interquartile range and a model-based estimate. For narrative purposes, we reviewed the utility of common morphological CT criteria for abscesses, such as central hypodensity, the size of the collection, bulging, rim enhancement, and presence of air, as well as sensitivity and specificity values reported by the original reports.

RESULTS

23 studies were found reporting 1453 patients, 14 studies in children (771 patients), two in adults (137 patients), and seven including all ages (545 patients). PPV ranged from 0.67 to 0.97 in individual studies, had a median of 0.84 (0.79-0.87), and a model-based pooled estimate of 0.83 (95% confidence interval 0.80-0.85). Most morphological CT criteria had considerable overlap between abscesses and cellulitis.

CONCLUSIONS

The pooled estimate of PPV is 0.83 for diagnosing neck abscesses with CT. False positives may be due to limited soft tissue contrast resolution. Overall, none of the morphological criteria seem to be highly accurate for differentiation between abscess and cellulitis.

Symptom duration and CT findings in pediatric deep neck infection

Objective: To investigate whether children with less than 48 hours of localized symptoms of deep neck infection are less likely to have an abscess on CT scan.

Study Design: Case series.

Subjects and Methods: The charts of children seen in a tertiary children's hospital for deep neck infections between 2000 and 2007 were reviewed.

Results: Of 179 children identified, 167 (93.3%) underwent a CT scan of the neck of which 102 (61.1%) were positive for abscess. There was no significant difference in the rate of abscess on CT between children with less than 48 hours of localizing symptoms and 48 or more hours of symptoms at 58.1 percent and 58.3 percent, respectively ( P = 0.98). Furthermore, there was no significant difference in age, gender, C-reactive protein levels, disease location, or length of stay between children with and without abscess on CT. White blood cell counts were significantly higher in the abscess group ( P = 0.01); however, the median white blood cell count in both groups was above normal.

Conclusion: Because duration of symptoms does not predict finding of abscess on CT, it is appropriate to obtain a CT scan upon presentation in all children with symptoms concerning for neck abscess.

Predicting deep neck space abscess using computed tomography

PURPOSE

To investigate objective measures that could increase the positive predictive value of computed tomography (CT) in diagnosing deep neck space infections (DNSIs).

METHODS

A retrospective analysis of patients surgically treated at a tertiary care hospital for DNSIs for more than 2 years were reviewed. Patients who had had CT with contrast scanning suggestive of deep neck space abscess within 24 hours before surgery were included. The average Hounsfield units for each abscess were calculated. Based on the intraoperative finding of pus, the patients were divided into groups. Student t tests compared the average Hounsfield units, white blood cell count, and maximum temperature between the groups. Outcomes were measured by comparing overall length of hospital stay, length of postoperative stay, and complications.

RESULTS

Of the 32 patients surgically drained, 24 (75%) had discreet collections of pus, whereas 12 (25%) did not. Hounsfield unit measurement was not reliable in distinguishing abscess from phlegmon. None of the other clinical variables studied to distinguish abscess from phlegmon were statistically different either. A statistical difference between the 2 groups was not identified.

CONCLUSION

Although CT with contrast plays an important role in the diagnosis and management of DNSIs, the decision for surgical drainage of an abscess should be made clinically. A negative exploration rate of nearly 25% despite careful selection criteria should be expected.

History of possible foreign body ingestion in children: don??t forget the rarities

Foreign body ingestion in children is a common presenting complaint to the emergency department. Although the majority of ingested foreign bodies pass through the gastrointestinal tract unaided, some children will require either non-surgical or surgical intervention. Retained oesophageal foreign bodies may cause a multitude of problems, including mucosal ulceration, inflammation or infection, and more seriously paraoesophageal or retropharyngeal abscess formation, mediastinitis, empyema, oesophageal perforation and aorta-oesophageal fistula formation. We present a case of a 12-month-old child in whom delayed diagnosis of glass ingestion resulted in the development of a retropharyngeal abscess, oesophageal perforation and mediastinitis. Such complications following foreign body ingestion in children are rare but potentially fatal. A high index of suspicion must be maintained in young children presenting with a possible history of foreign body ingestion as a delayed diagnosis may lead to significant morbidity and mortality. We review the literature surrounding paediatric retropharyngeal abscesses and mediastinitis.

Retropharyngeal abscess in children: clinical presentation, utility of imaging, and current management

OBJECTIVE

We sought to describe the clinical presentation of patients with retropharyngeal abscess (RPA), utility of imaging studies, and implications on management.

METHODS

A retrospective chart review was performed at a tertiary-care, pediatric hospital with cases identified by a discharge diagnosis of RPA; posttraumatic RPA cases were excluded. Patients without confirmatory radiographic findings, fluoroscopy, or computed tomography (CT) were excluded.

RESULTS

Sixty-four cases involving 64 patients were studied. The median age of the patients was 36 months; 48 (75%) of the 64 patients were younger than 5 years. The most common chief complaints were neck pain (38%), fever (17%), sore throat (17%), neck mass (16%), and respiratory distress or stridor (5%). In 29 children (45%), it was noted that there was limitation of neck extension, in 23 (36.5%) torticollis, and in 8 (12.5%) limitation of neck flexion. The physical examination revealed stridor with wheezing in only 1 patient (1.5%) and wheezing in 1 other (1.5%). Twenty-seven patients (42%) underwent surgery; 37 (58%) were treated with antibiotics only. Performance of a surgical procedure was significantly associated with CT scan findings. Ten (37%) of 27 patients with defined abscess on CT scan were treated with antibiotics alone. There were no treatment failures in either the antibiotic-only group or the antibiotics-plus-surgery group.

CONCLUSIONS

Children with RPA present with limitation of neck movement, especially difficulty extending their neck to look up. They rarely present with respiratory distress or stridor. CT scan is useful to distinguish patients with RPA from those with retropharyngeal cellulitis. Most patients with retropharyngeal cellulitis and some with RPA can be treated successfully without surgery.

[Upper airway obstruction (foreign bodies excluded)]

Upper airway obstruction is a frequent cause of admission to the emergency department and the intensive care unit. Symptoms are mainly represented by dyspnea and stridor. Severity must be rapidly assessed to allow adapted treatment and avoid cardiac arrest and hypoxic encephalopathy. The possible etiologies are numerous, with acquired and congenital ones, but the majority is represented by laryngitis, lymphoid hypertrophy and laryngotracheomalacia. In case of respiratory failure, treatment must first establish airway patency with bag and mask ventilation, and then intubation. If vital prognosis is not threatened, biologic, radiologic or endoscopic examination can be performed to identify the cause of the obstruction and treat it.

Retropharyngeal abscess management in children: current practices

Retropharyngeal abscesses (RAs) in children are uncommon in the modern antibiotic era. As a result, there are few large series outlining the management of these infections in contemporary literature. The goal of this study is to determine the current standard of care for RA. The membership of the American Society of Pediatric Otolaryngology was surveyed, and the response rate was 77.5%. Seventy-two percent of practitioners reported that CT is their preferred diagnostic method. Nearly two thirds recommended a trial of intravenous antibiotics at least occasionally for suspected RA before operative drainage was considered; 51% of respondents indicated that 20% to 40% of RA may resolve with antibiotics alone. Intraoral incision and drainage is the surgical technique preferred by 83% of respondents. Tracheotomy and short-term intubation (24 to 72 hours) are rarely required. This study defines current management practices for RA in children among pediatric otolaryngologists. Results are compared with those in the existing literature.

Correlation between computed tomography and surgical findings in retropharyngeal inflammatory processes in children

Retropharyngeal abscess (RPA) in children is a potentially life-threatening process which often requires immediate surgical intervention. Contrast enhanced computed tomography (CT) is utilized frequently to determine abscess versus cellulitis/phlegmon and aids in determining cases needing surgical drainage. The purpose of this retrospective study was to determine the accuracy of CT in distinguishing retropharyngeal abscess from cellulitis in children. The medical records of 32 children from 1989 to 1997 suspected of having a retropharyngeal abscess were reviewed. All patients included in the study underwent a CT scan as well as surgical exploration within 48 h of the scan. Two patients required two surgical procedures (n = 34). A comparison between CT results and operative findings was made to determine the accuracy of CT imaging in confirming the presence of RPA versus cellulitis. Suspected diagnosis of abscess or cellulitis/phlegmon on CT was confirmed at surgery in 25 of 34 cases (73.5%). The false positive rate of CT scan was 11.8% (4/34), while the false negative rate was 14.7% (5/34). Based on our results, CT is accurate in differentiating abscess from cellulitis in 73.5% of cases. Clinical findings, as well as radiologic findings, must be considered together prior to surgical drainage of a suspected retropharyngeal abscess in children.

Deep Neck Infections

Deep neck infections are less common in the antibiotic era, but when they do occur they remain serious infections. Historically, these infections carried significant morbidity and mortality due to the proximity of the airway, mediastinum, and other vital structures. Deep neck infections were once routinely treated with penicillin, and if infection progressed to abscess, surgical drainage was performed. In recent years the standard medical, surgical, and diagnostic approaches to deep neck infection have changed, and they continue to evolve. Physicians must be aware of these changes to optimally manage patients with deep neck infections.

Computed tomography in the evaluation of pediatric neck infections

In children, infections involving both the superficial and deep neck spaces are common. Children so affected typically present with fever, neck mass, neck stiffness, and, occasionally, airway compromise. Radiologic modalities used in the evaluation of neck infections include plain lateral neck radiography, ultrasound, computed tomography, and magnetic resonance imaging. All these modalities have proved useful in the treatment of such infections, specifically the decision to perform incision and drainage. The charts of 66 patients-33 with superficial and 33 with deep neck infections-were analyzed with respect to symptoms, signs, computed tomography findings, and need for surgical intervention. Computed tomography was not particularly helpful in superficial neck infections with regard to the decision to perform surgical drainage; however, it did localize and demonstrate the extent of infection. In deep neck infections we found a 92% correlation between computed tomographic evidence of an abscess and surgical confirmation of one. Contrast-enhanced computed tomography remains an excellent tool in the treatment of neck infections in children.

Supraglottic airway infections

Supraglottic infections are included among the more serious pediatric infections, although they are less common than other pediatric respiratory infections. Supraglottic infections include epiglottis (supraglottitis), retropharyngeal cellulitis, retropharyngeal abscess, and peritonsillar abscess. A high index of suspicion combined with rapid diagnosis and treatment are crucial to reducing the morbidity and mortality associated with these infections. A review of these infections, including diagnosis and treatment, is presented.

Space-occupying and life-threatening infections of the head, neck, and thorax

Infections of the deep structures of the head and neck are polymicrobial, rapidly progressive, and frequently life-threatening. The bacteriology, clinical presentation, and the need for multidisciplinary management of these infections are stressed. In addition, this article discusses selected head and neck infections of immunocompromised hosts and postexposure prophylaxis for serious infections of the pharynx.

Management of deep neck infection

Deep neck abscesses are serious complications of common upper respiratory tract infections in children. Children are especially prone to airway obstruction complicating deep neck abscess. Pediatricians must understand the presentations and treatment of deep neck abscesses to avoid potentially life-threatening complications.

Clinical indicators of childhood retropharyngeal abscess

Retropharyngeal abscess is a rare but distinctive cause of airway obstruction in childhood. Early recognition permits emergent airway management and surgical drainage. Even when the presentation is insidious and does not include respiratory compromise, early clinical diagnosis of retropharyngeal cellulitis and appropriate medical treatment may halt progression to an abscess. Delay in the diagnosis and management of a retropharyngeal abscess may lead to potentially lethal complications involving vital structures. A case of an infant whose diagnosis of retropharyngeal abscess was delayed because of absence of respiratory compromise is reported. Relapse of retropharyngeal abscess despite surgical drainage and appropriate antibiotic treatment was a complication of infection in this patient. Clinical indicators providing an early diagnosis of retropharyngeal infection, and aspects of evaluation, management, and outcome, are discussed.