Endgames Picture Quiz

A teenager with a cough, fever, and poor appetite

BMJ 2012; 344 doi: http://dx.doi.org/10.1136/bmj.e2821 (Published 26 April 2012) Cite this as: BMJ 2012;344:e2821
  1. Simona Turcu, respiratory fellow,
  2. Samatha Sonnappa, paediatric respiratory consultant
  1. 1Great Ormond Street Hospital, London WC1N 3JH, UK
  1. Correspondence to: S Turcu sfturcu{at}googlemail.com

A 14 year old girl presented to her local hospital with a three week history of progressively worsening cough, fever, and poor appetite, which had not responded to a week of oral antibiotics.

On examination she had a temperature of 38°C, was pale, not clubbed, and her oxygen saturations were 95% in air. There was a dull note on percussion, with reduced air entry on auscultation in the right upper zone of the chest, and no added sounds. The rest of the systemic examination was normal. At admission, blood tests showed haemoglobin 109 g/L (reference range 105-135), white blood cell count 12.7×106 cells/L (6.0-18), neutrophils 7.65×106 cells/L (2.0-6.0), C reactive protein 33 mg/L (0-5), erythrocyte sedimentation rate 116 mm in the first hour (10). Chest radiography and computed tomography were performed (figs 1 and 2). She was started on intravenous antibiotics and transferred to a tertiary centre for further management.

Questions

  • 1 What abnormality do the figures show and what is the most likely diagnosis?

  • 2 What other investigations would you perform and what differential diagnoses would you consider?

  • 3 What is the appropriate management?

  • 4 What are the possible complications of this condition?

Answers

1 What abnormality do the figures show and what is the most likely diagnosis?

Short answer

There is a round opacity with air fluid level in the right upper zone on the chest radiograph, which can be localised to the right upper lobe on the computed tomogram. The appearance suggests a lung abscess.

Long answer

A large circular mass can be seen in the right upper to mid zone on the chest radiograph with air fluid level within it (fig 3). The same lesion with air fluid level is seen on the chest computed tomogram and is localised to the right upper lobe (fig 4). The appearance suggests a right upper lobe lung abscess.

Figure3

Fig 3 Chest radiograph showing a circular mass with air fluid level in the right upper to mid zone (arrow)

Figure4

Fig 4 Chest computed tomogram showing the same lesion seen on the radiograph localised to the right upper lobe (arrow)

2 What other investigations would you perform and what differential diagnoses would you consider?

Short answer

Microbiological investigation of sputum, throat swab, and abscess fluid is recommended so that antibiotic treatment can be targeted. Differential diagnoses include loculated empyema, congenital cyst, hydatid cyst, saccular bronchiectasis, sequestration, and a necrotising tumour.

Long answer

Lung abscess is a necrotising infection characterised by a pus filled cavitary lesion that often complicates necrotising pneumonia. Primary lung abscesses occur in healthy children without lung parenchymal abnormalities, whereas secondary abscesses occur in children with underlying lung disease, such as congenital cystic lung lesions, cystic fibrosis, primary immunodeficiency, or neurological conditions that predispose to aspiration. Abscesses may develop over a course of weeks with tachypnoea, cough, and fever being the common symptoms.1

Common causative organisms include aerobic Gram positive bacteria (Streptococcus pneumonia, Staphylococcus aureus, Peptostreptococcus, Actinomyces), aerobic Gram negative bacteria (Klebsiella, Bacteroides, Fusobacterium, Proteus, Escherichia coli), anaerobic Gram positive bacteria (Bifidobacterium spp, Clostridium spp), anaerobic Gram negative bacteria (pigmented Prevotella, Bacteroides spp), and opportunistic organisms (Candida, Legionella, Mycobacterium). Abscesses often contain more than one organism.1 2 3 4

Microbiological investigations, including 16s polymerase chain reaction, of sputum and abscess fluid are recommended to enable antibiotic treatment to be targeted. However, microbiological information from sputum has limited value because of contamination with anaerobes from the oral cavity, and it is only helpful in abscesses caused by non-anaerobic organisms. Sputum should also be checked for acid and alcohol fast bacilli.

Our patient had raised inflammatory markers. The abscess was caused by a mixture of organisms—sputum grew Stenotrophomonas, microscopy of abscess fluid showed Gram positive cocci, 16s polymerase chain reaction was positive for Streptococcus pneumoniae, and Prevotella was identified on anaerobic cultures. A negative Mantoux test excluded cavitating tuberculosis and negative blood cultures excluded bacteraemia or endocarditis. The fact that she had previously been well, with a normal level of consciousness and no neuromuscular conditions or oesophageal dysmotility, suggests that the abscess was a primary one. To check her immunological status we measured immunoglobulin values, lymphocyte subsets, IgG subclasses, complement factors, and phagocyte function (using nitroblue toluene), all of which were normal. A negative sweat test ruled out cystic fibrosis. Histology of the abscess fluid showed no malignant cells.

Other differential diagnoses include loculated empyema, congenital cyst, hydatid cyst, saccular bronchiectasis, sequestration, and a necrotising tumour. Chest computed tomography or ultrasound can distinguish a lung abscess from a loculated empyema, necrotising pneumonia, or a congenital lung lesion. Vasculitis, sarcoidosis, aspergilloma, and pulmonary infarction are rare in children.1 3

3 What is the appropriate management?

Short answer

The treatment of lung abscess is not standardised and is based on experience. Most lung abscesses settle with conservative management, and four to six weeks of systemic broad spectrum antibiotics is the mainstay of treatment. In non-responsive patients, some centres perform percutaneous ultrasound guided aspiration or catheter drainage, whereas others favour open thoracotomy.

Long answer

Conservative management with hospital admission and antibiotics for four to six weeks is the first line treatment. In non-responders there are three main options, which differ between medical centres:

  • Antibiotics with ultrasound guided needle aspiration

  • Antibiotics with percutaneous drain placement

  • Antibiotics with marsupialisation of the lung abscess cavity via thoracotomy.

There are no clear guidelines about the duration of antibiotic treatment. Standard practice is to use parenteral antibiotics until clinical symptoms abate and to follow with oral antibiotics for up to six weeks. When information on antibiotic sensitivity is unavailable, empirical treatment must be comprehensive and cover common pathogens. The initial antibiotics of choice are penicillin or a third generation cephalosporin associated with clindamycin and metronidazole. Consider fungal cover in immunocompromised children.4

Children with a lung abscess usually do well with antibiotics alone and surgical intervention is rarely needed. However, with the advent of interventional radiology, computed tomography guided drainage and pigtail catheter insertion are used in non-responders.5 6 7 If patients deteriorate despite antibiotics and drainage, thoracotomy with marsupialisation of the abscess cavity (cutting a slit into the cyst and suturing the edges of the slit to form a continuous surface from the exterior to the interior) is the next step. Pulmonary resection remains debatable and is limited to immunocompromised children.8

Our patient was treated with clindamycin, piptazobactam, metronidazole and underwent ultrasound guided percutaneous needle aspiration.

4 What are the possible complications of this condition?

Short answer

Complications include spontaneous rupture of the abscess, sepsis, bronchopleural fistula, pleural cutaneous fistula, and pleural fibrosis. Our patient developed septic shock after spontaneous rupture of the abscess, with multiorgan failure that required management in intensive care.

Long answer

Complications are rare in the antibiotic era and include abscess rupture, spread of infection to other lung segments, bacteraemia with metastatic infection and septic shock, bronchopleural fistula, pleural cutaneous fistula, residual cavity with reinfection, persistent pleural effusion, and pleural fibrosis.1 3 Death occurs in 15-20% of adults with a lung abscess, whereas in children the outcome is more favourable, with mortality being around 5% and occurring mainly in those with a secondary lung abscess.3 4

While on parenteral antibiotics after percutaneous drainage, our patient developed septic shock and multiorgan failure secondary to spontaneous rupture of the abscess, which required management in intensive care.

Patient outcome

Our patient made a complete recovery from the sepsis and multiorgan failure. When stable on the ventilator she underwent marsupialisation of the abscess cavity. She was discharged home after six weeks and followed up in the respiratory clinic for one year, until complete resolution of symptoms. At one year follow-up her lung function was normal; her chest radiograph was also normal apart from some residual pleural thickening.

Notes

Cite this as: BMJ 2012;344:e2821

Footnotes

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

  • Patient consent obtained.

References