Community Acquired Pneumonia ,Bacterial-Standard Treatment Guidelines

Introduction

Pneumonia, an infection of the pulmonary parenchyma is a commonly encountered, potentially life-threatening condition in clinical practice. In light of the recent pandemics of multidrug-resistant bacterial infections world-over, pneumonia has been categorized as either community-acquired pneumonia (CAP) or health care-associated pneumonia (HCAP). The subcategories of HCAP include hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). In spite of the availability of potent new antimicrobials, CAP is associated with considerable morbidity and mortality, particularly in elderly patients and those with significant co-morbid illnesses.

Ministry of Health and Family Welfare, Government of India has issued the Standard Treatment Guidelines for Community Acquired Pneumonia(Bacterial).
Following are the major recommendations :

Case definition

For both situations of care:

1. Symptoms and signs consistent with an acute lower respiratory tract infection (productive cough, rusty sputum, pleuritic chest pain, etc.); presence of at least one systemic manifestations (either a symptom complex of sweating, fever, shivers, aches and pains and/or temperature of >38 o C or more).


2. New focal signs on physical examination of the chest.


3. New chest radiograph evidence of pneumonic consolidation which is at least segmental or present in more than one lobe and is not known to be previously present for which there is no other explanation.


4. Confirmation of aetiological diagnosis by blood culture/sputum culture and/or molecular diagnostic methods.

INCIDENCE OF THE CONDITION IN OUR COUNTRY

Estimates form the developed world suggests that CAP occurs in 8 to 15 per 1000 persons per year; the highest rates are at the extremes of age. No systematic studies have been carried out till date to define the incidence of CAP in India and reliable epidemiological data are lacking.

DIFFERENTIAL DIAGNOSIS

1. Common

• Pulmonary embolism/infarction


• Pulmonary oedema


• Bronchogenic carcinoma


• Pulmonary tuberculosis


• Bronchiectasis

2. Uncommon

• Pulmonary eosinophilia/eosinophilic pneumonia


• Cryptogenic organising pneumonia


• Pulmonary alveolar haemorrhage


• Foreign body


• Congenital pulmonary abnormality (eg. lobar sequestration)


• Radiation pneumonitis

PREVENTION AND COUNSELING

1. Persons hospitalized with CAP who smoke should be counseled regarding smoking cessation.


2. Respiratory hygiene measures, including the use of hand hygiene and masks or tissues for patients with cough, should be used in outpatient settings and casualty as a means to reduce the spread of respiratory infections.

OPTIMAL DIAGNOSTIC CRITERIA, INVESTIGATIONS, TREATMENT & REFERRAL CRITERIA

Situation 1: At Secondary Hospital: Optimal Standards of Treatment in Situations where technology and resources are limited

Clinical Diagnosis
Symptoms

The onset of CAP is acute. Patients present with symptoms suggestive of acute lower respiratory tract infection, cough, rusty sputum, pleuritic chest pain, and constitutional symptoms, such as, fevers, sweating, chills, rigors, body aches and pains; temperature of >38 o C or more.

Signs

Patients with CAP look sick and toxic. New and focal signs of pneumonic consolidation (reduced movements and expansion, increased tactile vocal fremitus, dull note on percussion, tubular bronchial breathing, increased vocal resonance, aegophony and whispering petriloquy; pleural rub) are present on physical examination of the chest. Signs due to complications, such as, pleural effusion, empyema, sepsis syndrome may also be present.

Investigations

Chest radiograph:A chest radiograph is the cornerstone to establishing the diagnosis of CAP or an alternative diagnosis, and to assess the extent of the disease and the presence of complications such as pleural effusion, lung abscess etc.

In all admitted patients:

1. Pulse oximetry: pulse oximtery is useful for assessment of gasexchange status.


2. Sputum Gram's stain, culture; smear examination for acid-fast bacilli; blood culture.


3. Full haemogram.


4. Serum biochemistry (blood urea, serum creatinine, liver function tests).

Arterial blood gas (ABG) analysis: ABG analysis is helpful in detecting acute respiratory failure that may complicate the course of CAP.

Assessment of severity: This is best assessed by CURB-65 scoring system [confusion, urea >7mmol/L, respiratory rate >30/min, blood pressure (systolic <90 mmHg or diastolic <60 mmHg), Age >65yrs] and guides admission to ICU and antibiotics administration. Pneumonia Severity Index (PSI) a prognostic model to identify those with low risk of death.

Treatment

Standard Operating procedure
In-Patient
General therapeutic measures

SpO2 monitoring by pulse oximetry.

Adequate circulation and blood pressure is ensured using volume infusion and/or vasopressors.

Decision to admit

• The decision to admit patients with one or more adverse factors (confusion, respiratory rate > 30/min; systolic blood pressure <90 mmHg or diastolic blood pressure <60 mmHg; age more than 65 years) without severity factors (hypoxaemia, bilateral or multilobar involvement on chest radiograph) should be individualized.


• Patients with one or more severity factors listed above need hospitalization.


• Admission into an ICU: for patients with septic shock requiring vasopressors or with acute respiratory failure requiring intubation and mechanical ventilation, direct admission into ICU will be required. Admission to an ICU is also recommended for patients with 3 of the following minor criteria for severe CAP: respiratory rate >30 breaths/min; PaO2/FIO2 ratio 250; multilobar infiltrates; confusion/ disorientation; uraemia (blood urea nitrogen level >20 mg/dL); leukopenia (total leukocyte count, < 4000 cells/mm 3 ), thrombocytopenia (platelet count <100,000/mm3 ), hypothermia (core temperature <36o C); and hypotension requiring aggressive fluid resuscitation.

Antibiotic treatment of the aetiological cause of CAP
4.1 In-patient antibiotic therapy
4.1.1 In-patients, non-ICU treatment

When admitted, these patients are treated with intravenous beta- lactam plus macrolide (Table 1 ).

Table 1
Choice of antibiotics for in-patient treatment of CAP

Choice of drug
First choice Second choice Third choice	ntravenous beta-lactam Cefotaxime 2 g q8h Ceftriaxone 1 g q12h Co-amoxyclav 1.2 g q8h	Daily dosage Macrolide Azithromycin 500 mg qd

• Duration of antibiotic therapy is 7 to 10 days based on clinical response.


• A switch to oral therapy can be made at 48-72 hours as most patients with CAP will have an adequate clinical response within 3 days, which includes improvement in cough and dyspnoea, absence of fever, decreasing white blood cell count and functioning gastrointestinal tract with adequate oral intake.


• Patient may be discharged on the same day if medical and social factors are favorable.


• Pleuritic pain should be relieved using drugs such as paracetamol.

Supplemental oxygen therapy

In patients with hypoxaemia, spontaneous ventilation using a face mask with a high flow gas delivery system can be used to deliver a FIO2 of up to 0.5 to 0.6.

Out Patient

Out-patient antibiotic therapy
The choice of antibiotics for out-patient treatment of CAP is as follows. For previously healthy patients and those who have not used antimicrobials within the previous 3 months, treatment with oral macrolide (e.g., azihtromycin) is indicated. For patients with comorbidities such as chronic heart, lung, liver or renal disease, diabetes mellitus, alcoholism, malignancies, asplenia, immunosuppressing conditions or use of immunosuppressing drugs, or use of antimicrobials within the previous 3 months, and patients in regions with a high rate (>25%) of infection with high-level [minimum inhibitory concentration (MIC) 16 mg/mL] macrolide-resistant Streptococcus pneumoniae, oral treatment with coamoxyclav in combination with macrolide is recommended.

Referral criteria

1. Patients presenting with two or more adverse factors (confusion, respiratory rate> 30/min; systolic blood pressure <90 mmHg or diastolic blood pressure <60 mmHg; age more than 65 years) or one or more severity factor (hypoxaemia, bilateral or multilobar involvement on chest radiograph).


2. Diagnosis not clear.


3. Patients not responding to therapy.

Situation 2: At Tertiary hospital where higher-end technology is available

Clinical Diagnosis
As in situation V.1 a) above

Investigations

As in situation V.1b) above PLUS

Two blood cultures (minimum 20 ml)

1. Sputum or other respiratory tract specimen for Gram stain, bacterial culture and sensitivity tests; molecular diagnostic methods (e.g., polymerase chain reaction for respiratory pathogens)


2. Pleural fluid, if present, for microscopy, culture and pneumococcal antigen detection.


3. Investigations for Legionella pneumonia:

• Urine for Legionella antigen.


• Sputum or other respiratory tract specimens (for Legionella culture and direct immunofluorescence) (if available).

4.Investigations for atypical bacterial pathogens:

• If available, sputum or other respiratory sample for PCR or direct immunofluorescence (or other antigen detection test) for Mycoplasma pneumoniae, Chlamydia spp, Pneumocystis jirovecii (if at risk).

5.Imaging studies: ultrasonography of the chest is useful for detecting complications such as pleural effusion, empyema. In non-responders, computed tomography of the chest can help in detecting an underlying malignancy and complications, such as, lung abscess.

6.Bronchoscopic procedures: should selectively be used in individual patients for aetiological confirmation and ruling out an alternative diagnosis, such as, malignancy.

Treatment:
Standard Operating procedure
a. In Patient
As in situation V.1c)a.1 above PLUS

1.General therapeutic measures

• Patients should be assessed for volume depletion and may require intravenous fluids.


• Prophylaxis of venous thromboembolism with low molecular weight heparin should be considered for all patients who are not fully mobile.


• Nutritional support should be given during prolonged illness.


• Airway clearance techniques should be considered if the patient has sputum and difficulty in expectoration or in the event of a pre-existing lung condition.

2 Antibiotic therapy
As described under V.4 above PLUS

In-patients, ICU treatment

• A beta-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus azithromycin are recommended.


• For penicillin-allergic patients, a respiratory fluoroquinolone and aztreonam are recommended.


• If Pseudomonas is a consideration, an antipseudomonal beta-lactam (e.g., piperacillin tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin or levofloxacin (750 mg) are recommended.

Or

• The above beta-lactam plus an aminoglycoside and azithromycin

Or

• The above beta-lactam plus an aminoglycoside and an antipseudomonal fluoroquinolone are recommended.


• For penicillin-allergic patients, aztreonam may be substituted for above beta-lactam).


• Prior to use of respiratory fluoroquinolones, active pulmonary tuberculosis should be excluded.


• If community acquired methicillin-resistant Staphylococcus aureus is a consideration, vancomycin or linezolid can be added.

Supplemental oxygen therapy

All patients should receive appropriate oxygen therapy with monitoring of oxygen saturation and inspired oxygen concentration with the aim to maintain PaO2 at 60 mm Hg or above and SpO2 between 94%–98%.

• High concentrations of oxygen can safely be given in patients who are not at risk of hypercapnic respiratory failure.


• Oxygen therapy in patients at risk of hypercapnic respiratory failure complicated by ventilatory failure should be guided by repeated ABG measurements.

Ventilatory support

Patients with CAP who develop acute respiratory failure require mechanical ventilation for maintaining gas exchange with minimal complications.

Management of complications

• Parapneumonic effusion/empyema.


• Early thoracocentesis is indicated for all patients with a parapneumonic effusion.


• Patients found to have an empyema should have effective pleural fluid drainage and appropriate antibiotic therapy. Streptokinase may be instilled if loculation(s) present.

Lung abscess

• This condition is described in detail in another chapter

Out Patient
Not applicable

WHO DOES WHAT? and TIMELINES

Doctor: diagnosis and management including counseling
Nurse: implementation of orders, monitoring of patients and counseling
Technician: investigations

Situation	HUMAN RESOURCES	INVESTIGATIONS	DRUGS & CONSUMABLES	EQUIPMENT
1	1.Physician 2.Nurse 3.Radiographer 4. Laboratory technician	1.Chest X-ray 2. USG chest 3. Pulse oximetry 4. ABG 5. Serum biochemistry 6. Hemogram 7. Sputum smear and culture 8. Sputum for AFB 9. Blood culture 10. HIV ELISA for high risk group	1.Oral and i.v. antibiotics 2. Streptokinase	1. X-ray machine 2. USG machine 3. Pulse oximeter 4. ABG machine 5. Oxygen cylinders 6. Nebulizers 7. Microbiology laboratory services 8. Hematology and biochemistry laboratory services
2	Above plus 1.Intensivist 2.Nurse and technician for assisting with bronchsocopy 3.Nursing staff trained in ICU care 4.Pathologist	Above plus 1.CT chest 2.Bronchoscopy	Above plus 1.Oxygen supply 2.Tubes and other disposables for thoracocentesis (when indicated)	Above plus 1.CT machine 2.Bronchoscope and facilities for bronchoscopy 3.Clinical pathology laboratory service 4.Microbiology service with conventional, serological and molecular diagnostic facilities for aetiological diagnosis confirmation 5.ICU 6.Noninvasive and invasive ventilators

Guidelines by The Ministry of Health and Family Welfare :

Dr S.K. SHARMA
AIIMS