3.08 - Respiratory Tract Infections [updated]

Algorithm for the Diagnosis community acquired pneumonia (CAP):

1) Is there pneumonia?

Patients need to fulfill at least TWO of A and ONE of B

A. Clinical criteria:

      • Acute onset of fever (T ≥ 38oC).

      • Recent onset of cough or worsening of cough (< 2 weeks duration).

      • New onset of increased sputum production or a change in the character of the sputum (yellowish or greenish).

      • Recent onset of progressively increased dyspnoea.

      • Acute onset of pleuritic chest pain.

      • Auscultatory findings suggestive of pneumonia on physical examination which include bronchial breath sounds, increased vocal resonance, crepitations.

      • Raised total white cell counts (> 11 x 109 /L).

      • For those with pleural effusion, pleurocentesis confirm the presence of neutrophilic inflammatory exudate.

AND

B. Imaging criteria:

      • Radiographic image (CXR or CT thorax) shows evidence of lung field infiltrates.

      • For patients who have a normal CXR at presentation but have signs and symptoms suggestive of pneumonia, a diagnosis of pneumonia could still be confirmed in retrospect if a repeat chest imaging demonstrates evidence of pneumonia within 48 hours after admission.

2) Essential Investigations

  • Chest X-ray

  • Sputum for culture

  • Blood culture (in case of moderate to severe CAP)

3) Assess Severity

  • Stratify patient according to CURB 65 Score:

Confusion

Urea > 7 mmol/L

Respiratory Rate ≥ 30 / min

Blood Pressure - SBP < 90 mmHg; DBP ≤ 60 mmgHg

Age > 65 years old

  • Score 0-1: Home antibiotics unless patient has other co-morbidity or difficult social circumstances.

  • Score 2: Admit to hospital.

  • Score 3: Admit to hospital and consider ICU referral.

A) Adults

* Asthma exacerbation

Clinical practice guidelines recommend against empiric antibiotic therapy for the treatment of an asthma exacerbation, because most respiratory infections that trigger an exacerbation of asthma are viral rather than bacterial

B) Paediatrics

Disease / Etiology

Preferred

Alternative

Comments

Community Acquired Bacterial Pneumonia, Pleural Effusion and Empyema

Chlamydia trachomatis

Bordetella pertussis

3 months to 5 years

Streptococcal pneumoniae

Haemophilus influenzae

Staphylococcus aureus

Mycoplasma pneumoniae

1 - 3 months

Streptococcal pneumoniae

Haemophilus influenza

Staphylococcus aureus

Ampicillin 50mg/kg/dose IV q6H

AND /OR

Cloxacillin 50mg/kg/dose IV q6H

Co-amoxiclav 25-30mg/kg/dose (Amoxicillin component) IV q8H

OR

Cefuroxime 25mg/kg/dose IV q8H

Use Cloxacillin if one suspects Staphylococcus aureus (MSSA) pneumoniae / sepsis in critically ill infants, children < 1 year of age or in the presence of pneumatocoeles.

For patients with significant beta-lactam allergy, macrolides are alternatives.

Add IV Metronidazole or change Amoxicillin to Co-amoxiclav if aspiration of anaerobes is a possibility.

Outpatient:

Amoxycillin 25-30mg/kg/dose PO q8H

Inpatient:

Ampicillin 50 mg/kg/dose IV q6H

Erythromycin 15mg/kg/dose PO q6H OR

Azithromycin (preferred choice for infant < 1 month old):

< 6 months old: 10mg/kg/dose PO q24H for 5 days

≥ 6 months old: 10 mg/kg/dose PO q24H on Day 1 then 5 mg/kg/dose PO q24H on Day 2 – 5

Co-amoxiclav 25mg/kg/dose (Amoxicillin component) PO q12H

Use Co-amoxiclav 30mg/kg/dose for pneumonia with acute otitis media

Cefuroxime 15mg/kg/dose PO q12H

Erythromycin ethylsuccinate 20mg/kg/dose PO q12H

Co-amoxiclav 25-30mg/kg/dose (Amoxicillin component) IV q8H

OR

Cefuroxime 25-30mg/kg/dose IV q8H

Azithromycin 10 mg/kg/dose PO q24H on Day 1 then 5 mg/kg/dose PO q24H on Day 2 – 5

Moraxella catarrhalis

> 5 years

Streptococcal pneumoniae

Mycoplasma pneumonia

Outpatient:

Amoxycillin 15mg/kg/dose PO q8H

Inpatient:

Ampicillin 50 mg/kg/dose IV q6H

Erythromycin ethylsuccinate 20mg/kg/dose PO q12H

Co-amoxiclav 25mg/kg/dose (Amoxicillin component) PO q12H

Co-amoxiclav 25-30mg/kg/dose (Amoxicillin component) IV q8H

OR

Cefuroxime 25-30mg/kg/dose IV q8H

Co-amoxiclav 25mg/kg/dose (Amoxicillin component) PO q12H

Non Cystic Fibrosis Bronchiectasis

In patients chronically colonized with Pseudomonas aeruginosa (2 consecutive positive cultures or 3 positive cultures in 1 year)

Patient with no previous bacteriology result.

Co-amoxiclav 25-30mg/kg/dose (Amoxicillin component) IV q8H

Cefuroxime 25-30mg/kg/dose IV q8H

OR

Ceftriaxone 50 mg/kg/dose IV q24H

Follow the most recent sputum bacteriology result in deciding which antibiotics to use.

The total duration of antibiotics should be for 14 days.

Azithromycin 5 mg/kg/dose (M, W, F) is considered especially when there are frequent exacerbations and decline in lung function.

Addition of nebulized Amikacin for 1 to 3 months should be considered:

Cystic Fibrosis Antibiotic Prophylaxis

Nebulized antibiotic as prophylactic treatment

Pseudomonas aeruginosa

Burkholdelia cepacia complex

Oral Antibiotic Prophylaxis

Cloxacillin:

< 10 kg: 125 mg q12H

10 - 15 kg: 250 mg q12H

> 15 kg: 25 mg/kg q12H

Azithromycin (immunomodulator):

< 15 kg: 10 mg/kg q24H (M,W,F)

15 - 40 kg: 250 mg q24H (M,W,F)

> 40 kg: 500 mg q24H (M,W,F)

The aim of prophylactic Cloxacillin is to reduce Staphylococcus aureus infection and subsequent inflammation during the time of lung development when the lung is most vulnerable. It is used in ALL children below 5 years old or in children > 5 years when there are more than 2 isolates of Staphylococcus aureus in a year.

To be used for 3 months

Nebulized Amikacin:

Bronchospasm can be reduced by:

i) Diluting with water

ii) Pre-dose with bronchodilator.

First dose in hospital

OR

Nebulized Colomycin (Colistin):

Pseudomonas aeruginosa only

Nebulized Gentamicin:

Infective Pulmonary Cystic Fibrosis Exacerbation

Staphylococcus aureus

Streptococcus pneumonia

Haemophilus Influenza

Pseudomonas aeruginosa

Chronic Pseudomonas Infection (Defined as 3 positive cultures at least 2 months apart and within 1 year)

Burkholderia Capecia complex

Outpatient:

If patient is on cloxacillin prophylaxis, Co-amoxiclav 25mg/kg/dose (Amoxicillin component) PO q12H

Co-trimoxazole (Trimethoprim component) 5mg/kg/dose PO q12H

OR

Doxycycline:

8-11 years: 4.4mg/kg/dose PO q24H on Day 1 then 2.2mg/kg/dose (can increase up to 4.4mg/kg/dose) PO q24h thereafter for 2-4 weeks

If liver function normal, can consider combination of:

Rifampicin 10mg/kg/dose PO q12H

AND

Fusidic acid 10mg/kg/dose PO q8H

Inpatient:

Cloxacillin 50 mg/kg/dose IV q6H.

>12 years: 200mg q24H on Day 1 then 100mg q24H thereafter (can increase to 200mg) for 2 -4 weeks

Precaution: Use of quinolones in paediatric patients is associated with increased incidence of adverse reaction related to joint i.e. tendonitis, tendon rupture

If the repeat sputum is negative for PA, then stop the oral Ciprofloxacin and continue nebulized Amikacin / Gentamicin for a total of 3 months.

If there is a substantial pseudomonal free period (> 3 months), the patient is treated in same manner as 1st isolate.

Once chronic infection is established, there is a trend for the pseudomonas to become mucoid and more resistant to antibiotics. The aim of further treatment is to reduce the colony numbers in order to suppress the inflammatory response.

For chronically colonized patient, alternating monthly treatment of nebulized antibiotics (Gentamicin / Amikacin / Colistin) for 3 months i.e. Neb Gentamicin /Amikacin/ Gentamicin OR Neb Amikacin /Colistin/ Amikacin

Surface swabs are taken for surveillance which includes right and left nostril, inguinal and sputum.

For MRSA nasal carriage: Topical Mupirocin / Bactroban to anterior nares. Patients will have to use Chlorhexidine wash on the skin once daily for 5 days.

Following treatment, sputum samples are obtained and repeated bi-monthly.

If positive on 2nd screen, oral treatment is repeated.

If remains positive following 2 full courses of oral treatment or during an infective exacerbation, then consider admission IV Vancomycin for 14 days.

The response to treatment is monitored by checking pulmonary function tests, CXRs and watching IgE titre as this should fall over time to more normal levels.

Monitor liver function.

Outpatient:

Co-amoxiclav 25mg/kg/dose (Amoxicillin component) PO q12H

for 4 weeks

Cefuroxime 15mg/kg/dose PO q12H for 2 weeks

Cefuroxime 30mg/kg/dose IV q8H for 2 weeks

Inpatient:

Co-amoxiclav 25-30mg/kg/dose (Amoxicillin component) IV q8H for 2 weeks

1st isolate:

Ciprofloxacin 20 mg/kg/dose PO q12H

(max dose 750 mg q12H)

+

Nebulised Gentamicin / Amikacin for 3 months

Re-culture the sputum after 3 weeks.

If positive:

Ceftazidime 50 mg/kg/dose IV q8H (max 9 gm/day)

AND

Amikacin 30 mg/kg/dose IV q24H (max 2 gm) (Amikacin level) for 2 weeks

During exacerbation:

Outpatient:

Ciprofloxacin 20 mg/kg/dose PO q12H

(max dose 750 mg q12H) for 2 weeks

Inpatient or elective tuning,

Ceftazidime 50 mg/kg/dose IV q8H (max 9 gm/day)

AND

Amikacin 30 mg/kg/dose IV q24H (max 2 gm) (Amikacin level) OR Gentamicin 10mg/kg/dose IV q24H for 2 weeks.

Piperacillin-Tazobactam 100mg/kg/dose of piperacillin IV q8H

OR Meropenem 40mg/kg/dose IV q8H

AND

Amikacin 30 mg/kg/dose IV q24H (max 2 gm) (Amikacin level) OR Gentamicin 10mg/kg/dose IV q24H for 2 weeks.

Followed by nebulized Amikacin / Gentamicin for 3 months.

Ceftazidime 50 mg/kg/dose IV q8H (max 9 gm/day)

AND

Meropenem 40mg/kg/dose IV q8H (max 2 gm q8H)

for 2 weeks

Polymyxin B (Resistant):

< 2 years old: 0.75 - 2 mg/kg/dose IV q12h over 60-90 min

> 2 years old : 0.75 - 1.5 mg/kg/dose IV q12h over 60-90 min

Aztreonam 75 mg/kg IV q8H (max 8 gm/day)

Tobramycin 10 mg/kg/day IV q24H (max 600 mg/day).

Chronic Burkholderia Capecia complex:

Doxycycline:

8-11 yrs: 4.4mg/kg/dose PO q24H on Day 1 then 2.2mg/kg/dose (can increase up to 4.4mg/kg/dose) PO q24H thereafter for 2-4 weeks

>12 yrs: 200mg q24H on Day 1 then 100mg q24H thereafter (can increase to 200mg) for 2 -4 weeks

Neb Meropenem:

6-12 years: 125mg q12H

Stenotrophomonas maltophilia

MRSA

Outpatient: Co-trimoxazole (Trimethoprim component) 5mg/kg/dose PO q6-12H

for 4 weeks.

Inpatient:

Co-trimoxazole (Trimethoprim component) 5 mg/kg/dose IV q6-12H

OR Levofloxacin 8-10 mg/kg/dose IV q12H

OR

Ceftazidime 50 mg/kg/dose IV q8h

>12 years : 250mg q12H

Levofloxacin 8-10mg/kg/dose PO q12H

Doxycycline:

8-11 years: 4.4mg/kg/dose q24H on day 1 then 2.2mg/kg/dose (can increase up to 4.4mg/kg/dose) q24H thereafter for 2-4 weeks

>12 years: 200mg q24H on day 1 then 100mg q24H thereafter (can increase to 200mg) for 2 -4 weeks

Outpatient:

Rifampicin 10 mg/kg/dose PO q12H AND

Co-trimoxazole (Trimethoprim component) 5mg/kg/dose PO q12H for 2 weeks

Clindamycin (community acquired) 10mg/kg/dose PO q8H

Rifampicin 10 mg/kg/dose PO q12H

AND

Sodium Fusidate 10 - 15 mg/kg (250 - 500 mg) PO q8H

for 2 weeks

Allergy Bronchopulmonary Aspergilosis

Inpatient:

Vancomycin 15mg/kg/dose IV q8H

Resistance/ Treatment failure: Linezolid used in isolation for 2 weeks.

< 12 years: 10 mg/kg/dose q8H

> 12 years: 600 mg q12H

Pulsed Methylprednisolone

10 - 15 mg/kg/dose (max 1gm/dose) IV q24H for 3 days every month.

Voriconazole as a 2nd line agent for patients who have not responded to or cannot tolerate twice daily Itraconazole:

2-11 years: 9 mg/kg/dose (max 350 mg) q12H

12-14 years:

< 50 kg – 9 mg/kg/dose (max 350 mg) q12H

> 50 kg – 400 mg q12H for 2 doses then 200 mg q12H (max 300 mg q12H)

15 years and above:

< 40 kg – 200 q12H for 2 doses then 100 mg q12H (max 150 mg q12H)

> 40kg – 400 mg q12H for 2 doses then 200 mg q12H (max 300 mg q12H)

IV Voriconazole 9mg/kg/dose IV q12H for 2 doses, followed by 8mg/kg/dose IV q12H

Prednisolone 2 mg/kg/day for 2 weeks, reduced to 1 mg/kg/day for 2 weeks, then alternate 1 mg/kg/day for 2 weeks.

Wean slowly over next 4 months reducing dose by 2.5 mg / 5 mg every 2 weeks.

AND

Invasive Aspergillus

Itraconazole

1 month - 12 years: 5 mg/kg/dose PO q12h (max 200 mg q12H)

> 12 years: 200 mg q12H (stopped 2-4 weeks after the oral steroids are finished)

Nebulised Amphotericin B (non-liposomal) may be used in difficult cases after physiotherapy:

< 10 years: 5 mg q12H

> 10 years: 10 mg q12H

IV Amphotericin (deoxycholate) 0.5 -1.0mg/kg/dose q24H