pulmonary disorders
Community Acquired Pneumonia
Treatment of Community Acquired Pneumonia
Risk stratification for determination of site of care Antibiotics Antivirals for influenza or varicella Supportive measures via risk prediction rules may be used to estimate mortality risk and thus help guide decisions regarding hospitalization. These rules have been used to identify patients who can be safely treated as outpatients and those who require hospitalization because of high risk of complications (see table Risk Stratification for Community-Acquired Pneumonia (the Pneumonia Severity Index) ). However, these rules should supplement, not replace, clinical judgment because many unrepresented factors, such as likelihood of adherence, ability to care for self, ability to maintain oral intake, should also influence triage decisions. Intensive care unit (ICU) admissionis required for patients who Need mechanical ventilation Have hypotension (systolic blood pressure ≤ 90 mm Hg) that is unresponsive to volume resuscitation Other criteria, especially if ≥ 3 are present, that should lead to consideration of ICU admission include Hypotension requiring fluid support Respiratory rate>30/minute PaO2/fraction of inspired oxygen (FIO2)<250 Multilobar pneumonia Confusion Bloodureanitrogen (BUN)>19.6 mg/dL (>7 mmol/L) Leukocyte count<4000 cells/microL (<4×109/L) Platelet count<100,000/microL (<100×109/L) Temperature<36° C The Pneumonia Severity Index (PSI) is the most studied and validated prediction rule. However, because the PSI is complex and requires several laboratory assessments, simpler rules such as CURB-65 are usually recommended for clinical use. Use of these prediction rules has led to a reduction in unnecessary hospitalizations for patients who have milder illness. InCURB-65, 1 point is allotted for each of the following risk factors: Confusion Uremia (BUN ≥19 mg/dL [6.8 mmol/L]) Respiratory rate > 30 breaths/minute SystolicBlood pressure < 90 mm Hg or diastolic blood pressure ≤ 60 mm Hg Age ≥65years Scores can be used as follows: 0 or 1 points: Risk of death is < 3%. Outpatient therapy is usually appropriate. 2 points: Risk of death is 9%. Hospitalization should be considered. ≥ 3 points: Risk of death is 15 to 40%. Hospitalization is indicated, and, particularly with 4 or 5 points, ICU admission should be considered. In clinical settings where access to a BUN measurement is not readily available, aCRB-65 scorecan be used instead. Use of CRB-65 scores is similar to that for CURB-65, with 0 points: appropriate for outpatient therapy; 1-2 points: consider hospitalization; ≥ 3 points: consider ICU admission. 4 hours after presentation. Because pathogen identification is difficult and takes time, the empiric antibiotic regimen is selected based on likely pathogens and severity of illness. Consensus guidelines have been developed by many professional organizations; one widely used set is detailed in the table Community-Acquired Pneumonia in Adults (see also For children, treatment depends on age, previous vaccinations, and whether treatment is outpatient or inpatient. Forchildren treated as outpatients, treatments are dictated by age: < 5 years:Amoxicillinoramoxicillin/clavulanate is usually the drug of choice. If epidemiology suggests an atypical pathogen as the cause and clinical findings are compatible, a macrolide (eg,azithromycin,clarithromycin) can be used instead. Some experts suggest not using antibiotics if clinical features strongly suggest viral pneumonia. ≥ 5 years:Amoxicillinor (particularly if an atypical pathogen cannot be excluded)amoxicillinplus a macrolide.Amoxicillin/clavulanate is an alternative. If the cause appears to be an atypical pathogen, a macrolide alone can be used. Forchildren treated as inpatients, antibiotic therapy tends to be more broad-spectrum and depends on the child's previous vaccinations: Fully immunized (againstS. pneumoniaeandH. influenzaetype b):Ampicillinorpenicillin G(alternatives areceftriaxoneorcefotaxime). If MRSA is suspected,vancomycinorclindamycinis added. If an atypical pathogen cannot be excluded, a macrolide is added. Not fully immunized:Ceftriaxoneorcefotaxime(alternative islevofloxacin). If MRSA is suspected,vancomycinorclindamycinis added. If an atypical pathogen cannot be excluded, a macrolide is added. Full details are described in theClinical Practice Guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America. With empiric treatment, 90% of patients with bacterial pneumonia improve. Improvement is manifested by decreased cough and dyspnea, defervescence, relief of chest pain, and decline in white blood cell count. Failure to improve should trigger suspicion of An unusual organism Resistance to the antimicrobial used for treatment Empyema Coinfection or superinfection with a 2nd infectious agent An obstructive endobronchial lesion Immunosuppression Metastatic focus of infection with reseeding (in the case of pneumococcal infection) Nonadherence to treatment (in the case of outpatients) Wrong diagnosis (ie, a noninfectious cause of the illness such as acute hypersensitivity pneumonitis) When usual therapy has failed, consultation with a pulmonary and/or infectious disease specialist is indicated. Antiviral therapymay be indicated for select viral pneumonias.Ribavirinis not used routinely for respiratory syncytial virus pneumonia in children or adults but may be used occasionally in high-risk children age < 24 months. For influenza,oseltamivir75 mg orally twice a day orzanamivir10 mg inhaled twice a day started within 48 hours of symptom onset and given for 5 days reduce the duration and severity of symptoms in patients who develop influenza infection. Alternatively, baloxavir started within 48 hours of symptom onset can be given in a single dose of 40 mg for patients 40 to 79 kg; 80 mg is used for patients ≥ 80 kg. In patients hospitalized with confirmed influenza infection, observational studies suggest benefit even 48 hours after symptom onset. Acyclovir10 mg/kg IV every 8 hours for adults or 250 to 500 mg/m2body surface area IV every 8 hours for children is recommended for varicella lung infections. Though pure viral pneumonia does occur, superimposed bacterial infections are common and require antibiotics directed againstS. pneumoniae,H. influenzae, andS. aureus. Follow-up x-rays are generally not recommended in patients whose pneumonia resolves clinically as expected. Resolution of radiographic abnormalities can lag behind clinical resolution by several weeks. Chest x-ray should be considered in patients with pneumonia symptoms that do not resolve or that worsen over time. Supportive care includes fluids, antipyretics (as needed for high grade fever), analgesics, and, for patients with hypoxemia, oxygen. Prophylaxis against thromboembolic disease and early mobilization improve outcomes for patients hospitalized with pneumonia. Smoking Cessation should also be done for smokers. 