Category Archives: Respiratory

Pneumonia

General paediatrics, Respiratory, ,

SIGN/BTS pneumonia guideline revised 2011 – microbiology bit more subtle now: yes, anything between 1/3 and 2/3 are viral, particularly under 2 years, and probably a third are mixed, but you still get pneumococcus and mycoplasma in infants.

Bugs

Strep pneumoniae (Pneumococcus) is the most common bacterial cause of pneumonia in childhood.

Pneumococcus causes about one-third of radiologically confirmed pneumonia in children aged <2 years.

PCV7 has dramatically decreased IPD due to vaccine serotypes in the UK, but a steady increase in vaccine serotype replacement is evident in the UK.

Group A streptococci and S aureus disease are more likely than pneumococcal to progress to ICU or empyema.

Overall, viruses account for 30-67% of CAP (community acquired pneumonia) cases in childhood and are more frequently identified in children aged <1 year than in those aged >2 years.

1/3 of cases of CAP (8-40%) represent a mixed infection.

Mycoplasma is not unusual in children aged 1-5 years.

Age is a good predictor of the likely pathogens:

  • Viruses alone are found as a cause in younger children in up to 50%.
  • In older children, when a bacterial cause is found, it is most commonly S pneumoniae followed by mycoplasma and chlamydial pneumonia

Wheeze used to be seen as excluding pneumonia, but now only comment is that it can be one of the clinical features of pneumonia, none of which is very specific.  Bacterial pneumonia should be considered in children when there is:

  • persistent or repetitive fever >38.5C, together with chest recession and a raised respiratory rate. [D].

Clinical presentation

Wheeze and chest pain can be symptoms of pneumonia. But none of the symptoms of pneumonia are very specific for pneumonia.

In children over 3yrs, history of difficulty breathing is an additional valuable symptom.

Consider bacterial pneumonia if recurrent/persistent fever >38.5 together with recession and tachypnoea.

  • Re-consultation (in the community) for persistent fever can suggest pneumonia
  • Reassess if pneumonia symptoms do not respond to treatment
  • Refer to hospital if sats <92%
  • Absent breath sounds with dull percussion suggest effusion, refer to hospital
  • Children with pneumonia in hospital should be reassessed if fever persists 48hr after starting treatment, or if there is increased work of breathing or agitation/distress
  • Microbiogical investigations for pneumonia include blood culture, NPA for PCR/IF, serology for resp viruses, Mycoplasma, Chlamydia, pleural fluid C+S/Pneumococcal antigen/PCR.

Investigations

CXR not useful in mild cases, certainly not necessary if admission not being considered. I would consider if hypoxia was disproportionate to degree of breathlessness (suggests collapse), suspicion of effusion (stony dullness on percussion) or pneumothorax.

CXR is not useful in establishing viral vs bacterial vs atypical aetiology!

Repeat CXR in convalescence is only required for persisting symptoms, lobar collapse or round pneumonia.

CRP etc not useful in establishing viral vs bacterial vs atypical aetiology!

Microbiological investigation not necessary routinely, but important if complications or ICU needed.

Antibiotics

Under 2yrs, mild lower resp tract symptoms are not usually due to pneumonia (esp if pneumococcal immunized) so do not need to be given antibiotics – but review if symptoms persist.

No longer age related antibiotic cut offs.

Amoxicillin is first choice, macrolide is an alternative (as is co-amox).  Macrolide should be added if poor response or if severe (D level recommendations though).

In influenza pneumonia (higher rate of staph), co-amoxiclav is recommended [D].  Similarly for measles.

Oral antibiotics equivalent to IV (if tolerated) even in severe disease (PIVOT trial, Nottingham).  But IV for complicated or signs of septicaemia.  Recommended IV antibiotics include amoxicillin, co-amoxiclav, cefuroxime, cefotaxime, ceftriaxone. Rationalize as able, change to oral when clear evidence of improvement.

CAP-IT trial

2021 trial in UK & Ireland – excluded under 6 months and under 6kg or severe underlying chronic condition. Excluded anybody already treated with beta lactam antibiotics for 48+ hrs or any other antibiotic for any duration.

Twice daily amoxicillin 35-50mg/kg/d for 3 days was equivalent to higher doses for 7 days. Longer course had 2 days less cough. [JAMA 2021]

Susan Lipsett et al from Boston suggest that most of these kids would probably have improved without antibiotics anyway – they discharged 80% of kids who fulfilled CAP-IT criteria but who had normal x-rays without antibiotics (!) and only 2% came back! [JAMA Open 2024]

Management

Strongly against NG tubes in severely ill esp infants.  Use smallest nostril if cannot be avoided

Use oxygen if sats <=92%

Monitor bloods daily if on IV fluids

Chest physio is NOT beneficial – at least, not routinely, potentially if focal collapse identified and slow to come out of oxygen.

If going home, advice on managing fever, preventing dehydration, identifying deterioration.

Follow up severe pneumonia, empyema and lung abscess until recovered completely and CXR near normal.

Bronchiolitis treatment

General paediatrics, Respiratory

NICE guidance updated 2021.

Essentially supportive.  Oxygen, feeding, respiratory support if necessary.  Beware secondary bacterial infection, lobar collapse, pneumothorax, concomitant UTI.

Hypertonic saline

Not recommended by NICE. Cochrane 2010, patients treated with nebulized 3% saline had a significantly shorter mean length of hospital stay compared to those treated with nebulized 0.9% saline (MD -1.16 days, 95% CI -1.55 to -0.77, P < 0.00001).   No significant adverse events related to 3% saline inhalation were reported.  Not recommended for emergency departments as 2 doses didn’t seem to affect clinical scores.

But subsequent studies less impressive.  SABRE trial randomized 317 infants to 3% hypertonic saline nebulised every 6 h from admission compared with nothing (ie, standard care). No difference between the two arms of the study in time to discharge [Legg and Cunningham, Arch Dis Child 2015;100:1104-1105].

But AAP guidelines recommend nebulized hypertonic saline for infants hospitalized with bronchiolitis, with the expectation of reducing bronchiolitis scores and length of stay when it is expected to last more than 72 hours. Some think potentially an advantage for hypertonic saline in reducing admission rates from the emergency department [DOI: 10.5863/1551-6776-21.1.7]

High Flow

Franklin study of early high flow oxygen use – babies were randomized as soon as they needed oxygen.  Not generally what happens, of course.

  • Outcome was “escalation of care” ie signs requiring further intervention eg tachycardia, hypoxia. Intervention was high flow, of course.  Rate was 23%, but nearly a third of these did not meet the prespecified criteria (so doctor just decided they “needed” high flow anyway).
  • In sites without PICU, 28% of standard therapy group required escalation of care.  This is way in excess of the rate we would report in our unit.
  • No differences in length of stay or duration of O2 therapy.
  • Of 167 who “failed” on standard care, 61% responded to high flow.
  • No age effect.

So it seems to me that if you have facility to do high flow, you will find that at least a quarter of your oxygen dependent bronchiolitis babies “need” it.  I’m not sure this is a useful or meaningful study.  Babies may be more comfortable on high flow, and you may prevent the odd ICU admission, which is definitely worth considering. [N Engl J Med 2018 Mar 22;378(12):1121-1131.]

BIDS study

A study to see if safe to discharge babies with less than normal saturations.  RCT of 308 infants, no need to admit if sats >92% AND >50% feed requirements.

For those needing admission, start oxygen only if <90%, and only discharge once sats >90% continuously over 4hr period including sleep, and taking >75% feeds! Exclude babies with risk factors (<3/12, ex-prem, CLD etc– should have sats >92%)

Compared with standard pulse oximeter parameters (treat <94%), no difference in adverse events eg high dependency, readmission.  Excluded prems, recent oxygen therapy, CF or other chronic lung disease, immune deficit. [Edinburgh, Steve Cunningham, Lancet 2015; 386: 1041–48]

Study in emergency departments (n=213) found that babies discharged with artificially raised saturations (+3%) actually were less likely to be readmitted than babies with true oxygen saturations, suggesting that it’s a poor predictor (probably true for other respiratory conditions, too).

Combined bronchodilator and steroids

One study found better outcomes with neb adrenaline and systemic steroids but subgroup analysis and not adequately powered.

Swimming and asthma

General paediatrics, Respiratory, ,

For competitive swimmers, note FINA doping control rules (based on the World Anti-Doping Agency regulations). Most asthma medications are on the Prohibited List including inhaled steroids and inhaled Beta2 agonists.

Therefore, elite athletes with asthma must apply for special permission to use these medications, known as the “Therapeutic Use Exemption” (TUE) program.  If competing at FINA events, then you apply directly to the FINA Doping Control Review Board to have their applications considered. Lower level athletes should apply to their national anti-doping body.

Pertussis

General paediatrics, Infectious disease, Respiratory,

Whooping cough, caused by Bordetella pertussis. B parapertussis can cause similar illness but usually less severe. B. holmesii also seen.

Classically, Catarrhal phase (mild fever, productive cough, no pharyngitis) for a week, then Paroxysmal (coughing fits, often associated with vomiting, followed by characteristic inspiratory “whoop”), then Convalescent – persistent cough, traditionally 4-12 weeks (100 days)! Fever is rare, and in fact patients can often look relatively well between paroxysms, with clear chest and no respiratory signs. Young infants may present with apnoea rather than whooping.

Post tussive vomiting is pretty specific in adults, but only 66% in children.

Adult disease presents in its mild form as disturbed sleep, sweating, sinusitis or otitis, protracted cough (2 weeks or more). Cough associated with choking is characteristic, whereas sweating is not very sensitive or specific. Cough is non-productive (although there may be a sensation of retained secretions – question carefully!).

But probably underdiagnosed, esp where symptoms are chronic but mild, or in the third of cases where symptoms last less than 3 weeks.

In UK children aged 5-15 with persistent cough (ie over 14/7, in many cases severe) identified in primary care, at least 20% had evidence of recent infection with Bordetella pertussis,  (doi:10.1136/bmj.g3668) Hence reported incidence depends on quality of surveillance rather than actual prevalence! Probably the same everywhere. Note epidemiology below, with peaks every 2-5 yrs.

The reason for the chronic, persistent cough is still not clear (many infections cause similar ciliary disruption, and don’t cause such chronic symptoms).

Complications

  • Rarely encephalopathy, including seizures. Probably a direct toxin effect, plus hypoxia during paroxysms.
  • Hernias and rectal prolapse.
  • Secondary pneumonia is not uncommon, so if chest signs are present consider antibiotic treatment to cover other organisms.
  • Pneumothorax, aspiration, rib fractures in elderly
  • Sinusitis, otitis
  • Malignant pertussis – rapidly progressive ARDS, pulmonary hypertension and right heart failure, multiorgan failure. Hyperleukocytosis is predictive (contributes to endothelial damage?) – increase of greater than 10 per day associated with death in PICU (but not absolute count), as is CRP>20. Hyperhydration contraindicated of course, so ECMO and leucodepletion have been attempted.

Immunity

Although part of universal immunization schedule, immunity (from immunization or exposure) is pretty short lived viz 2-5yrs, so in vaccinated areas severe disease seen either pre-immunization ie young babies, or adolescent/adults after immunity has worn off.  Mums appear to be the source in 38% of cases, dads in 17% of cases. That suggests that half the cases come from other family members of the community.

In low coverage areas burden of disease is in 5 yr olds, because of regular exposure through life.

Epidemiology

Before the vaccine era, there were often in excess of 100 000 cases of pertussis per year in England and Wales. Whole cell pertussis was effective but was associated with seizures and in rare cases long term brain damage, leading to a fall in vaccine uptake in the 70s and a resurgence in cases. The acellular vaccine has less side effects.

In 2012, national outbreak declared in UK on basis of higher than usual prevalence.  Similar spike in numbers worldwide. New vaccination in pregnancy campaign, still on going – 90% effective against pertussis in babies, and disease less severe if infected.  Antibody transfer to baby but also reduced chance of close contact. Other countries boost teenagers.  Better vaccines would be nice! WHO recommends that countries still using whole cell vaccines continue to do so unless they can schedule boosters. See Vaccines.

Cause for outbreak uncertain: more sensitive diagnostic methods?  Enhanced awareness and reporting?  Less enduring protection after immunization with acellular vaccines (cf whole cell vaccines)? Mismatch between antigens in acellular vaccines and circulating strains of B pertussis? Although the largest increase in reported incidence seems to be in adolescents, children aged <3 months are at highest risk of serious morbidity and mortality from pertussis.

Diagnosis

Notifiable!

  • Lymphocytosis can be spectacular but not sensitive. Due to Pertussis toxin, as used in vaccine, which is specific to B pertussis but probably not that important for pathogenesis cf tracheal cytotoxin etc. Hence not seen post immunization (ie adults), in parapertussis, or in neonates (transplacental antibodies).
  • Culture from pernasal swab is not fantastically sensitive but is useful for genetic studies. False negatives mostly due to sampling late in course of disease.
  • PCR more sensitive than culture but false positives common (as usual with PCR).
  • Numerous different ELISA tests � be suspicious of any that are qualitative (pos/neg) rather than quantitative. IgG based are good, whole cell tend to be poor. Mouth swab test available.
  • Serology is of limited use for infants (transfer of maternal IgG), but you can always test the parents (Mum may have stored serum from pregnancy).

Differential

Asthma!  Cystic fibrosis.

Mycoplasma and adenovirus can cause chronic cough.

Treatment

7/7 erythromycin or clarithro, 3/7 azithro. Clarithromycin preferred in neonates, given association with pyloric stenosis (may also be a risk with azithro).  Co-trimoxazole as second line.  Makes little difference to clinical course, but does help reduce transmission. Treat within 3-4 weeks of start of illness.

48 hour isolation if treated, 21 days from onset if not.

Azithromycin  is as effective as erythromycin, gastrointestinal adverse events are much less, and compliance in general was markedly better [Pediatrics. 2004 Jul;114(1):e96-101 – pmid:15231980].

Still need full immunization course as natural disease does not confer long lasting immunity.

Prevention

“Cocooning” is the strategy of vaccinating a baby’s mother (AFTER BIRTH) and father (during pregnancy) to protect baby against pertussis. Considered cost effective although I can’t see any evidence… Tricky though, because getting dads/grandparents to vaccine appointments is harder than getting a mum at an antenatal appointment – and because any delay in vaccinating the mum after birth reduces the usefulness of the vaccine.

The US does both cocooning and vaccination in pregnancy, I believe.

Prophylaxis

Where vulnerable individuals eg unimmunized infants, asthmatics are exposed to a likely case, there is an argument for giving prophylactic erythromycin to all close contacts. See Health Protection Agency advice. Journal of Public Health Medicine 2002;24(3):200-206.