Evidence-based guidance from the BTS steers GPs through the maze of lower respiratory tract infections in children, as Dr Peter Saul explains


   

One of the most challenging situations in primary care is being faced late at night, at a patientÍs home or on-call centre, with a sick child. Respiratory illnesses make up the most common presenting picture, and establishing a working diagnosis and management plan is often fraught with difficulty.

The British Thoracic Society (BTS) Guidelines for the Management of Community Acquired Pneumonia in Childhood have been developed to assist doctors to identify, assess severity and manage those children suffering from lower respiratory tract infections in community settings. They have been developed alongside the adult CAP guidelines, and represent the first European guideline to cover this clinical area.

Although they describe ïpneumoniaÍ, the guidelines recognise that this term has important limitations in primary care because GPs seldom have immediate access to chest radiography to confirm diagnosis. They acknowledge that the term ïacute lower respiratory tract infectionÍ (LRTI) may be more helpful; the term recognises that distinguishing between viral pneumonia and acute bronchiolitis is difficult and not always clinically essential.

Although CAP in children is relatively common, there have been surprisingly few recent studies into incidence and mortality. Finnish figures dating from the 1980s extrapolated to the UK suggest that a GP with an average list size of 1700 may encounter around 13 cases per year. Most of these will be in younger children and most will be viral in origin.1,2

Reassuringly, this research reported that deaths were very rare, at 0.1 per 1000 per year. As with many infectious diseases, boys in the younger age groups are most at risk, in this case mainly from an increased susceptibility to infection with Streptococcus pneumoniae.

Other risk factors were identified in the study: for all children, recurrent respiratory infections during the previous year and a history of wheezing increased the risk, and in those aged under 5 years a history of surgically treated otitis media before the age of 2 years was an additional factor.

Causative organisms

Studies looking into the microbiological cause of CAP in children have encountered difficulties. Blood cultures have low yields,3 getting sputum is difficult and more invasive investigations are inappropriate. Furthermore, a host of variables in published studies make wider extrapolations difficult.

These variables include age of children studied, clinical setting, season, clinical location and whether diagnostic sampling coincided with an epidemic of a particular organism. The lack of validated laboratory markers and small sample size further complicate matters.

The guideline developers examined 11 papers published during the 1980s and 90s, only two of which covered UK populations. Statistics from the two most recent largestudies with the most comprehensive sets of results were able to establish an aetiology in 85% and 45%, respectively.4,5 They also found that a mixed viral/bacterial picture is present in 30% of cases of CAP.4,5

Key points from these studies are in Box 1 (below).

Box 1: Aetiology and epidemiology of CAP in childhood

  • Streptococcus pneumoniae is the most common bacterial cause of pneumonia in childhood
  • Age is a good predictor of the likely pathogens
    • Viruses are the most commonly found cause in younger children
    • In older children, when a bacterial cause is found, it is usually S. pneumoniae followed by mycoplasma and chlamydial pneumonia
  • A significant proportion of cases of CAP (8-40%) represent a mixed infection
  • Viruses alone appear to account for 14-35% of CAP in childhood
  • In 20-60% of cases a pathogen is not identified

Making the diagnosis

The key diagnostic feature is breathlessness, which may be associated with tachypnoea and chest recession.6,7 Other important features include fever8 and crackles and bronchial breathing on chest auscultation.7 Headache, chest and abdominal pain are often present. Auscultatory signs may not be present early in the disease. Wheezing is not a useful sign, and is more common in cases of Mycoplasma pneumoniae especially in older children,9 but can be confused with asthma.

Special investigations, in particular chest radiography, are not needed in primary care settings. Even if it were readily available, radiography will not distinguish between bacterial and nonbacterial pneumonia,10,11 nor does it offer much in terms of additional diagnostic information.12 The only exception is in children aged under 5 years with unexplained fever of >39°C, where it becomes necessary as part of a wider diagnostic screen.

Microbiological sampling is also unhelpful because of the difficulty in obtaining useful samples and the fact that most infections are viral in origin.

Table 1: Indications for hospital admission

Infants aged <1 year

Older children

SaO2 92%

SaO2 92%

Respiratory rate >70 breaths/min

Respiratory rate >50 breaths/min
Difficulty in breathing Difficulty in breathing
Intermittent apnoea, grunting Grunting
Not feeding Signs of dehydration
Concerns over the ability of the family to manage an ill child at home Concerns over the ability of the family to manage an ill child at home
Failure to improve within 48 hours Failure to improve within 48 hours

Assessment

Assessment is an important area upon which hinges the decision to manage at home or admit to hospital (Table 1, above and Figure 1 below). The key question is ïIs this child hypoxaemic?Í If so, he or she is at greater risk of death.7

Indicators of hypoxaemia are a respiratory rate >70 breaths/min in infants under 1 year and >50 breaths/min in older children. If a pulse oximeter is available, recordings of SaO2 of 92% or less would give rise for concern.

Figure 1: Community management of acute lower respiratory tract infection in children

Management

Children with acute LRTI are usually feverish with aches and pains, in particular headache, chest pain sometimes referred to the abdomen and, especially in the case of mycoplasma infections, there may be joint pains. Sometimes an associated upper respiratory tract infection such as otitis media will be present.

Antipyretics and analgesics should be given to keep the child comfortable and help reduce coughing. Parents will need advice on measures to relieve these symptoms as well as preventing dehydration and identifying any deterioration. Any child who is being cared for at home who deteriorates or fails to improve after 48 hours of treatment should be reviewed by the GP.

One of the difficulties in deciding whether to use antibiotics to treat a child with CAP is how to differentiate bacterial from viral aetiology. As doctors we are regularly entreated to reduce unnecessary prescribing. Unfortunately, the guidelines identify a dearth of studies upon which to base advice.

One study from Denmark addressed the issue and found no difference in the course of CAP (over half the cases of which were subsequently diagnosed as of viral aetiology) in a group of children aged 1 month to 6 years, irrespective of whether they were treated or not.13 There were some caveats to this study in respect to the diagnosis and the fact that some of the placebo group eventually received antibiotics.

Some studies have shown that there are no differences between management with a macrolide compared with penicillin-based antibiotics.14 Similar studies produced the same result when comparing cephalosporins with penicillin-based drugs.15

Although penicillin resistance is increasing, this seems to have little clinical impact on those children with resistant pneumococci treated with penicillins.16 For these reasons the guidelines recommend that amoxicillin remains the first choice for younger children, and macrolides for those aged 5 years and over, because of the risk of mycoplasma infection. Box 2 (below) summarises the antibiotic policies suggested.

Box 2: Antibiotic treatment

  • Young children presenting with mild symptoms of lower respiratory tract infection need not be treated with antibiotics
  • Amoxicillin is the first choice for oral therapy in children under 5 years; alternatives are cefaclor and macrolides
  • Macrolides should be used in children aged 5 years and over because of the risk of mycoplasma infection
  • Whatever the age of the child a macrolide should be used if chlamydia or mycoplasma infection is suspected, and amoxicillin if S. pneumoniae is suspected (unless the child is penicillin sensitive)

Providing the child can tolerate oral medication, there is no advantage in administering parenteral antibiotics at home.17

GPs faced with a child who is not improving within 48 hours need to re-evaluate the situation, considering such matters as compliance with treatment and the possibility of lung complications or an incorrect diagnosis. For those children making an uneventful recovery, follow up radiography is not required.

Prevention

The guidelines identify GPs as being particularly well placed to offer advice on preventative measures such as reducing smoking in the household and promoting Hib and pertussis vaccination.

Pneumococcal vaccine is effective in reducing pneumococcal disease,18 but there are insufficient data to make any recommendations on its use in UK populations.

Conclusion

These guidelines offer busy GPs some markers through the maze of LRTIs in children. In particular they help GPs with diagnostic pointers and offer methods of assessing severity. They indicate that in most cases children can safely be managed at home.

Traditional antibiotic regimens are supported but a useful distinction is made between those children under and over 5 years, with older groups being recommended a macrolide. The guidelines emphasise that milder cases do not need antibiotic treatment - but my guess is that it would be a brave doctor who did not prescribe.

References

  1. Jokinen C, Heiskanen L, Jalonen E et al. Incidence of community acquired pneumonia in the population of four municipalities in eastern Finland. Am J Epidemiol 1993; 137: 977-88.
  2. Korppi M, Heiskanen-Kosma T, Jalonen E et al. Aetiology of community acquired pneumonia in children treated in hospital. Eur J Paediatr 1993; 152: 24-30.
  3. Claesson BA, Trollfors B, Brolin I et al. Etiology of community acquired pneumonia in children based on antibody responses to bacterial and viral antigens. Pediatr Infect Dis J 1989; 8: 856-62.
  4. Juven T, Mertsola J, Waris M et al. Etiology of community acquired pneumonia in 254 hospitalized children. Pediatr Infect Dis J 2000; 19: 293-8.
  5. Wubbel L, Muniz L, Ahmed A et al. Etiology and treatment of community acquired pneumonia in ambulatory children. Pediatr Infect Dis J 1999; 18: 98-104.
  6. Harari M, Shann F, Spooner V et al. Clinical signs of pneumonia in children. Lancet 1991; 338: 928-30.
  7. Smyth A, Carty H, Hart CA. Clinical predictors of hypoxemia in children with pneumonia. Ann Trop Paediatr 1998; 18: 31-40.
  8. Campbell H, Byass P, Lamont AC et al. Assessment of clinical criteria for identification of severe acute lower respiratory tract infections in children. Lancet 1989; I: 297-9.
  9. Broughton RA. Infections due to Mycoplasma pneumoniae in childhood. Pediatr Infect Dis 1986; 5: 71-85.
  10. Courtoy I, Lande AE, Turner RB. Accuracy of radiographic differentiation of bacterial from nonbacterial pneumonia. Clin Pediatr (Phila) 1989; 28: 261-4.
  11. Clements H, Stephenson T, Gabriel V et al. Rationalised prescribing for community acquired pneumonia: a closed loop audit. Arch Dis Child 2000; 83: 320-4.
  12. Heulitt MJ, Ablow RC, Santos CC et al. Febrile infants less than 3 months old: value of chest radiography. Radiology 1988; 167: 135-7.
  13. Friis B, Andersen P, Brenoe E et al. Antibiotic treatment of pneumonia and bronchiolitis. A prospective randomised study. Arch Dis Child 1984; 59: 1038-45.
  14. Harris JA, Kolokathis A, Campbell M et al. Safety and efficacy of azithromycin in the treatment of community acquired pneumonia in children. Pediatr Infect Dis J 1998; 17: 865-71.
  15. Klein M. Multicenter trial of cefpodoxime proxetil vs. amoxycillin clavulanate in acute lower respiratory tract infections in childhood. International Study Group. Pediatr Infect Dis J 1995; 14: S19-22.
  16. Tan TQ, Mason EQ Jr, Barson WJ et al. Clinical characteristics and outcome of children with pneumonia attributable to penicillin-susceptible and penicillin-nonsusceptible Streptococcus pneumoniae. Pediatrics 1998; 102: 1369-75.
  17. Tsarouhas N, Shaw KN, Hodinka RL et al. Effectiveness of intramuscular penicillin versus oral amoxycillin in the early treatment of outpatient pediatric pneumonia. Pediatr Emerg Care 1998; 14: 338-41.
  18. (18) Black S, Shinefield H, Fireman B et al. Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Northern California Kaiser Permanante Vaccine Study Center Group. Pediatr Infect Dis J 2000; 19: 187-95.

Copies of the BTS Guidelines for the Management of Community Acquired Pneumonia in Childhood can be downloaded from www.thoraxjnl.com or www.brit-thoracic.org.uk

Guidelines in Practice, September 2002, Volume 5(9)
© 2002 MGP Ltd
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