Community Acquired Pneumonia (CAP) in Adults

Community Acquired Pneumonia (CAP) in Adults - Secondary care

Publication: 01/12/2007

Next review: 24/02/2025

Clinical Guideline

CURRENT

ID: 1200

Approved By: Improving Antimicrobial Prescribing Group

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

COMMUNITY ACQUIRED PNEUMONIA (CAP) IN ADULTS

Diagnostics
Empirical Treatment
Review by 72 Hours
Directed Therapy

DIAGNOSTICS

For patients with a presumed diagnosis of Community Acquired Pneumonia (CAP) the following diagnostic tests and investigations should be taken to confirm diagnosis and guide treatment options. These should be done prior to initiation of antibiotics.

All patients must have their CURB-65 score calculated to guide both diagnostics and treatment. The score should be documented in the notes and where possible on the prescription chart.

Score one for each of the following:

Confusion (new - AMTS 8 or less)
Urea (> 7mmol/L)
Respiratory rate (≥30)
Blood pressure (S <90 or D ≤60 mmHg)
Aged ≥ 65 years

A score of 0-1 indicates low severity, 2 = moderate severity and ≥3 = high severity.

If a patient has one of the following risk factors during their initial assessment this may lead to re-classification of severity:

Presence of co-existing lung disease
Hypoxia (SaO² < 92% or PaO₂ < 8kPa regardless of concentration of oxygen administered)
Bilateral or multi-lobar involvement on chest x-ray
Respiratory rate >40

All patients	Chest X-ray (within 4 hours of presentation to hospital)
	Procalcitonin
	CRP, FBC, U&E, arterial blood gas (if required to guide oxygen supplementation)
Patients with moderate to severe CAP (indicated by CURB-65 score ≥2)	Sputum culture for Microbiology, Culture & Sensitivity (MC&S) Ideally taken before starting antibiotics, in expectorating patients If unable to take before starting antibiotics this should only be taken if patient is not responding to treatment.
	Blood cultures (for moderate to severe CAP) before antibiotics
	Screening for atypical pathogens¹ should be undertaken if suspected in patients with moderate severity (CURB-65 = 2) and for all patients with severe severity (CURB-65 ≥3): Respiratory samples for viral PCR (note this includes mycoplasma) Urine sample (if required for legionella antigen)

During COVID pandemic: please refer to the guideline for management of adult patients with suspected COVID-19 (excluding ICU).

EMPIRICAL TREATMENT

Doses assume normal renal and hepatic function
Doxycycline and Levofloxacin are not suitable during pregnancy.

Recent influenza: If the patient has recently had influenza and secondary bacterial pneumonia is being treated then please select an alternative to Amoxicillin from the table (as per the severity score).

Empirical treatment for CAP
Duration²: Low - moderate: 5 days Severe infection: 5 days in total (IV and PO). IV antibiotics should be given for 24 hours then consider switching to oral.
Severity (CURB-65 score)	First line	Penicillin Allergy (and not pregnant)	Penicillin allergy and pregnant³(and able to tolerate cephalosporins)⁴
Low severity (CURB-65 = 0-1)	Amoxicillin PO 500mg 8-hourly	Doxycycline PO 200mg loading dose followed by 100mg 24-hourly	Clarithromycin PO 500mg 12-hourly
Low severity (CURB-65 = 0-1) and atypical pathogens suspected¹	Doxycycline PO 200mg loading dose followed by 100mg 24-hourly Note: if pregnant see ‘penicillin allergy and pregnant’		Clarithromycin PO 500mg 12-hourly
Moderate severity (CURB-65 = 2)	Amoxicillin PO 500mg 8-hourly	Doxycycline PO 200mg loading dose followed by 100mg 24-hourly	Clarithromycin PO 500mg 12-hourly
Moderate severity (CURB-65 = 2) and atypical pathogens suspected¹	Amoxicillin PO 500mg 8-hourly AND Clarithromycin PO 500mg 12-hourly		Clarithromycin PO 500mg 12-hourly
High severity (CURB-65 = ≥ 3) With no sepsis	Co-amoxiclav PO 625mg 8-hourly AND Clarithromycin PO 500mg 12-hourly	Levofloxacin ^5,6 PO 500mg 12-hourly	Clarithromycin PO 500mg 12-hourly AND Cefalexin PO 1g 6-hourly
High severity (CURB-65 = ≥ 3) With sepsis	Co-amoxiclav IV 1.2g 8-hourly AND Clarithromycin IV 500mg 12-hourly	Levofloxacin ^5,6 IV 500mg 12-hourly	Clarithromycin IV 500mg 12-hourly AND Cefuroxime IV 1.5g 8-hourly
IV to PO switch for patients with sepsis.	Co-amoxiclav PO 625mg 8-hourly AND Clarithromycin PO 500mg 12-hourly	Levofloxacin ^5,6 PO 500mg 12-hourly	Clarithromycin PO 500mg 12-hourly AND Cefalexin PO 1g 6-hourly

REVIEW BY 72 HOURS

By 72 hours of antibiotic treatment, diagnostics should have proven your initial diagnosis or guided to a new diagnosis. If your patient is prescribed IV antibiotics then they should be reviewed daily.

The review, outcome and future plans (where appropriate) should be documented in the medical notes.

IVOS	If your initial diagnosis is correct and the patient is prescribed IV antibiotics, review whether an oral switch is appropriate using the ACED criteria (see below). If they meet all 4 criteria (note CAP is not a deep seated infection) consider switching using the oral options listed in the table above. A - Afebrile for 24 hours C - Clinically improving E - Eating and drinking D - not Deep seated infection
Stop	If no signs of infection and diagnostics support this decision.
Change	If the patient is not clinically responding, check microbiology results to see if directed therapy is required or you may need to consider an alternative diagnosis (including tuberculosis, malignancy or other obstructing lesion, or complications including parapneumonic effusion/empyema).
Continue	If the patient is improving but does not fully meet ACED criteria. Review daily until ready to switch.

DIRECTED THERAPY

Doses assume normal renal and hepatic function.
Doxycycline and Levofloxacin are not suitable during pregnancy. The manufacturers of linezolid and teicoplanin recommend only using during pregnancy if the benefits outweigh the risks: a clinical decision should be made using the relevant teams for the patient’s care.

Organism	No known penicillin allergy	Penicillin allergy	Duration
Streptococcus pneumoniae	Benzyl penicillin 1.2g IV 6-hourly	Refer to sensitivities	5-7 days in total (IV and PO)²
Oral switch	Amoxicillin 500mg PO 8-hourly	Refer to sensitivities	5-7 days in total (IV and PO)²
Meticillin-susceptible S. aureus	Flucloxacillin 2g IV 6-hourly	Refer to sensitivities	7-14 days⁷ in total (IV and PO)
Oral switch	Flucloxacillin 1g PO 6-hourly	Refer to sensitivities	7-14 days⁷ in total (IV and PO)
Meticillin-resistant S. aureus	1st line: Linezolid 600mg PO 12-hourly 2nd line: Teicoplanin IV 6mg/kg (see prescribing guidance)	N/A	14-21 days in total (IV and PO)
Oral switch	1st line: Linezolid 600mg PO 12-hourly 2nd line: If linezolid is contraindicated: Doxycycline 100mg PO 24-hourly. If pregnant: discuss with microbiology	N/A	14-21 days in total (IV and PO)
Legionellosis	Levofloxacin ⁵ 500mg PO 12-hourly If pregnant: discuss with microbiology	N/A	7-10 days (of levofloxacin), extended to 14-21 if severe disease or immunocompromised
Mycoplasma pneumoniae	Clarithromycin PO 500mg 12-hourly	N/A	5-7 days
Haemophilus influenzae	Check susceptibilities: Amoxicillin 1g IV 8-hourly OR Co-amoxiclav 1.2g IV 8-hourly	Refer to sensitivities	5-7 days in total (IV and PO)
Oral switch	Amoxicillin 1g PO 8-hourly OR Co-amoxiclav 625mg PO 8-hourly PLUS Amoxicillin 500mg PO 8-hourly	Refer to sensitivities	5-7 days in total (IV and PO)
Recent travel	Contact Microbiology or Infectious diseases for advice

Provenance

Record:	1200
Objective:
Clinical condition:	Community Acquired Pneumonia
Target patient group:	Patients presenting with an acute lower respiratory infection associated with recently developed radiological signs Pneumonia is defined as 'community acquired' if it presents prior to or within the first three days of hospital admission.
Target professional group(s):	Secondary Care Doctors Secondary Care Nurses Pharmacists
Adapted from:

Evidence base

REFERENCES

NICE Pneumonia (community acquired): antimicrobial prescribing. NICE guideline [NG138]. Published September 2019. Accessed 2nd April 2020.
Note: this was used for initial peer review copy. It was subsequently archived by NICE and replaced with NG173 which guided change in antibacterial choices for final update.
NICE COVID-19 Rapid guideline: antibiotics for pneumonia in adults in hospital (NG173. Published 1st May 2020. Accessed July 2020
BTS. Guidelines for the Management of Community Acquired Pneumonia in Adults Updated 2009. Accessed 2nd April 2020.
O’Driscoll BR, Howard LS, Earis J, et al. British Thoracic Society Guideline for oxygen use in adults in healthcare and emergency settings . BMJ Open Resp Res 2017;4: e000170. doi:10.1136/
BMJ Best Practice. Atypical Pneumonia. December 2019. Accessed 7th April 2020.

Approved By

Improving Antimicrobial Prescribing Group

Document history

LHP version 5.0

Related information

FOOTNOTES

Atypical bacterial pneumonia is caused by atypical organisms (these are not detectable on Gram stain and cannot be cultured using standard methods). Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila are the most common organisms. Atypical bacterial pneumonia is characterized generally by a symptom complex that includes headache, low-grade fever, cough, and malaise. Constitutional symptoms often predominate over respiratory findings.
Stop antibiotic treatment after 5 days unless microbiological results suggest a longer course is needed or the person is not clinically stable (fever in the past 48 hours, or more than 1 sign of clinical instability [systolic BP <90 mm Hg, heart rate >100/min, respiratory rate >24/min, arterial oxygen saturation <90% or PaO₂ <60 mmHg in room air]). A total of 10 days may be required in some patients.
NICE recommends the use of erythromycin in pregnancy. The authors reviewed this option and on balance felt that clarithromycin was also considered safe to use in pregnancy and due to 12-hourly rather than 6-hourly dosing would be preferable for the patient.
Refer to guideline - Assessment and Management of a patient presenting with a history of Penicillin Allergy
See MHRA advice for restrictions and precautions for using fluoroquinolone antibiotics due to very rare reports of disabling and potentially long-lasting or irreversible side effects affecting musculoskeletal and nervous systems. Warnings include: stopping treatment at first signs of a serious adverse reaction (such as tendonitis), prescribing with special caution in people over 60 years and avoiding co-administration with a corticosteroid (March 2019).
Before prescribing levofloxacin, consider the possibility of tuberculosis, to reduce risk of promoting quinolone resistance in tuberculosis.
If bacteraemic, minimum of 14 days. Longer course required if abscess.

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