Types of pneumonia covered by guidelines
Pneumonia guidance separates community- and hospital-acquired illness, uses CURB-65 for risk, and flags when broader cover or admission is needed.
Applies to adults in UK primary and secondary care.
UK clinical guidelines for pneumonia primarily address community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP), and ventilator-associated pneumonia (VAP), with distinctions based on the setting of onset and specific risk factors to guide appropriate investigation and management; CAP, occurring in a patient not recently hospitalised, is the most common presentation in primary and secondary care and is typically managed based on severity assessment using tools like CURB-65 to decide between community or hospital treatment, with empirical antibiotic therapy informed by local resistance patterns and the likelihood of atypical pathogens, while HAP, developing 48 hours or more after admission and not incubating at the time of admission, and VAP, arising more than 48 hours after endotracheal intubation, present distinct challenges due to the higher probability of infection with multidrug-resistant organisms, necessitating broader-spectrum antibiotic coverage and a thorough assessment for other sources of infection; aspiration pneumonia, often overlapping with these categories, is specifically considered in patients with risk factors like impaired consciousness or dysphagia, requiring coverage for anaerobic bacteria; guidelines also provide direction on healthcare-associated pneumonia (HCAP), though this classification's utility is debated, focusing on patients with recent healthcare contact such as residency in a nursing home or chronic dialysis, who may harbour resistant pathogens similar to HAP; paediatric pneumonia is addressed separately, with emphasis on age-specific pathogens like respiratory syncytial virus in infants and Mycoplasma pneumoniae in older children, guiding investigations and antimicrobial choice, while pneumonia in the immunocompromised host, including those with HIV, solid organ transplants, or on immunosuppressive therapy, requires a low threshold for investigation and broader differential diagnoses including opportunistic infections like Pneumocystis jirovecii; throughout all types, guidelines stress the importance of prompt diagnosis supported by clinical assessment, chest X-ray, and relevant microbiological tests, coupled with early administration of antibiotics, oxygen therapy for hypoxia, and fluid management, with regular monitoring of severity scores to guide escalation or de-escalation of care and therapy duration, alongside preventive measures such as vaccination against Streptococcus pneumoniae and influenza.
Assessment and severity scoring
Initial assessment of suspected community-acquired pneumonia (CAP) in adults should focus on identifying clinical stability and risk of deterioration, beginning with a thorough history to establish symptom onset (typically acute with cough, dyspnoea, pleuritic pain, sputum production, and systemic upset like fever or confusion), alongside a review of pre-existing comorbidities (such as chronic respiratory, cardiac, renal, or liver disease, diabetes, or immunocompromise) and relevant risk factors (including recent travel, smoking status, and functional status or frailty); physical examination must prioritise vital signs—recording temperature, heart rate, respiratory rate, blood pressure, and oxygen saturation on room air—and chest findings (like focal crepitations or bronchial breathing), while also assessing for signs of severe sepsis (e.g., altered mental status) as these directly inform severity scoring and subsequent management decisions. The cornerstone of severity assessment in the UK is the use of validated clinical prediction tools, primarily the CURB-65 score, which stratifies patients based on five criteria: Confusion (abbreviated mental test score ≤8), Urea >7 mmol/L, Respiratory rate ≥30/min, Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg), and age ≥65 years, with each positive criterion scoring one point, leading to a risk classification where a score of 0 suggests low severity and potential for home management, a score of 1 or 2 indicates moderate severity typically requiring hospital assessment and likely admission, and scores of 3 or more signify high severity and a high risk of mortality, necessitating urgent hospital admission and consideration of intensive care; for patients under 65, the CRB-65 score (omitting urea) is a useful alternative for primary care or initial triage, though it is less validated for in-hospital decision-making. It is crucial to interpret these scores within the broader clinical context, as they are prognostic aids rather than absolute directives; for instance, a patient with a CURB-65 score of 1 but significant hypoxaemia (SpO₂ <92% on air), severe comorbidities, or social circumstances that preclude safe home care would still warrant hospital admission, and conversely, clinical judgement may support home management for a patient with a score of 2 if they are otherwise stable, have good support, and can be closely monitored. For patients requiring hospital admission, a more comprehensive assessment is mandatory, including baseline investigations such as a chest X-ray to confirm the diagnosis and identify complications (like parapneumonic effusion), full blood count, urea and electrolytes, liver function tests, C-reactive protein (CRP) to monitor response, and blood cultures and sputum culture if possible before antibiotic administration; arterial blood gas analysis is essential in hypoxaemic patients to assess for type 1 or type 2 respiratory failure and acid-base status, which further refines severity assessment. In the hospital setting, the pneumonia severity index (PSI) may sometimes be used for risk stratification, particularly for identifying very low-risk patients who could be considered for outpatient treatment, but its complexity limits routine use in UK emergency departments where CURB-65 remains the predominant tool; additionally, clinicians must maintain a high index of suspicion for atypical pathogens or specific scenarios, such as aspiration pneumonia in patients with impaired swallow or Legionella in those with recent travel or specific exposures, which might not be fully captured by severity scores alone. Ultimately, the goal of severity scoring is to ensure patients receive care in the most appropriate setting, guide empirical antibiotic therapy choices (including the need for broader-spectrum cover in severe cases), and prompt early senior review or critical care input for high-risk individuals, with continuous re-assessment being paramount as a patient's condition can change rapidly.
Antibiotic treatment guidance
Pneumonia management in the UK requires prompt antibiotic therapy guided by an assessment of severity, setting of acquisition, and patient-specific risk factors, with treatment decisions primarily informed by national guidelines from NICE. For community-acquired pneumonia (CAP) in adults who can be treated at home and do not have significant co-morbidities or risk factors for unusual pathogens, a five-day course of oral amoxicillin is the first-line empiric treatment, as it provides effective cover against the most common causative organism, *Streptococcus pneumoniae*; in patients with penicillin hypersensitivity, a macrolide such as clarithromycin or erythromycin is a suitable alternative, while doxycycline may be considered in certain cases. For adults with moderate-severity CAP requiring hospital admission, dual therapy with intravenous amoxicillin (or benzylpenicillin) and a macrolide like clarithromycin is recommended to provide broader coverage, including for atypical organisms like *Legionella pneumophila* and *Mycoplasma pneumoniae*; this regimen should be switched to oral antibiotics once the patient shows clinical improvement, typically after 48-72 hours, with a total treatment duration of 7-10 days depending on the clinical response. In cases of high-severity CAP, often managed in an ICU setting, co-amoxiclav combined with a macrolide is frequently used to address potential gram-negative organisms and *Staphylococcus aureus*, with the need for broader spectrum agents like a respiratory fluoroquinolone (e.g., levofloxacin) or a third-generation cephalosporin considered based on local resistance patterns and individual patient factors. For hospital-acquired pneumonia (HAP), including ventilator-associated pneumonia (VAP), antibiotic choice must account for the higher likelihood of multidrug-resistant organisms such as *Pseudomonas aeruginosa* and MRSA; local antibiotic formularies and hospital antimicrobial stewardship policies are critical here, with empiric treatment often involving a broad-spectrum beta-lactam agent like pipercllin-tazobactam or a carbapenem, potentially combined with a second agent active against pseudomonas, with therapy de-escalated as soon as microbiology results allow. Aspiration pneumonia requires careful differentiation from chemical pneumonitis, with antibiotics indicated if infection is suspected, typically involving agents effective against oral anaerobes, such as co-amoxiclav or, in penicillin-allergic patients, clindamycin, while avoiding routine anaerobic cover in uncomplicated CAP. Pediatric pneumonia management differs, with amoxicillin remaining first-line for most cases, while macrolides are reserved for suspected atypical infections or penicillin allergy, with duration typically also being five days. Across all patient groups, timely initiation of antibiotics is crucial, ideally within four hours of diagnosis in a hospital setting, and clinicians must always review treatment based on clinical response, chest X-ray findings, and any available microbiological results, including spulture culture and sensitivity, blood cultures, and, when indicated, urinary antigen tests for *Legionella* or *S. pneumoniae*; antibiotic stewardship principles should be adhered to, ensuring the narrowest effective spectrum is used for the shortest effective duration to minimise resistance and side effects, with a focus on intravenous to oral switch as soon as the patient is clinically stable.
Hospital vs community management
The decision to manage pneumonia in hospital or the community is a critical one, dependent on a comprehensive clinical assessment of disease severity, the patient's underlying health status, and their social circumstances, with the primary goal being to identify those at risk of clinical deterioration who require inpatient care for closer monitoring, intravenous therapies, and supportive treatment; the assessment of severity is central to this decision-making process, with validated clinical prediction scores such as the CURB-65 score (Confusion, Urea >7 mmol/L, Respiratory rate ≥30/min, low Blood pressure [systolic <90 mmHg or diastolic ≤60 mmHg], and age ≥65 years) being widely used in UK practice to provide an objective measure of risk, where a score of 0 or 1 typically suggests suitability for community management, a score of 2 indicates consideration for hospitalisation or enhanced community support such as Hospital at Home services if available and appropriate, and a score of 3 or more signifies severe pneumonia necessitating urgent hospital admission, often to a high-dependency or intensive care unit, though it is crucial to remember that these scores are an adjunct to, not a replacement for, clinical judgement, and factors such as hypoxaemia (SpO2 <92% on air), significant comorbidities (e.g., chronic heart, lung, liver, or renal disease, diabetes, immunosuppression), social isolation, an inability to take oral medication, or clinical concern about the patient's capacity to cope at home should strongly favour hospital admission regardless of the calculated score; for patients deemed suitable for community management, treatment should be initiated promptly with oral antibiotics guided by local formularies and susceptibility patterns, typically amoxicillin for low-severity community-acquired pneumonia in patients without comorbidities, with clarithromycin or doxycycline added if atypical pathogens are suspected or in areas with high rates of penicillin-resistant pneumococcus, while for those admitted to hospital, initial empirical antibiotic therapy is broader and often intravenous, such as co-amoxiclav combined with a macrolide like clarithromycin, with a switch to oral therapy once the patient is clinically improving, afebrile, and able to swallow; supportive management in hospital includes oxygen therapy to maintain target saturations (94–98% for most patients, or 88–92% for those at risk of hypercapnic respiratory failure), fluid resuscitation for dehydration or sepsis, and analgesia, with careful monitoring of physiological observations; a key component of hospital management is ensuring a safe and timely discharge, which can be considered when the patient has been afebrile for 24 hours, has stable vital signs, and is able to manage oral medications and nutrition, with a follow-up plan in place, which may include a chest X-ray in 6 weeks for patients over 50 to ensure resolution and exclude an underlying malignancy, particularly in smokers.