NOSOCOMIAL PNEUMONIA

Is defined as a lower respiratory tract infection occurring after 48 hrs of admission to a hospital or nursing home. It is the second most common nosocomial infection in hospital practice after urinary tract infection. It is commonly caused by gram-negative pathogens and needs aggressive diagnostic approach with prompt recognition and urgent treatment to reduce morbidity and mortality; often the strains causing nosocomial pneumonia are multiple.

I. Epidemiology II. Etiologies III. Symptoms IV. Labs V. Radiology: VI. Bronchoscopic Diagnosis VII.Management: Antibiotics VIII.Risk factors and suggested infection-control measures

 

I. Epidemiology
    A. Complicates up to 1% of hospitalizations
    B. Mortality: 30-50%

II. Etiologies
  A. Aspiration following(CVA)
     1. Streptococcus Pneumoneae
     2. Anerobic Bacteria
  B. Mechanical ventilation
     1. Coliform bacteria Pseudomonas aeruginosa (most common)
     2. Staphylococcus aureus
  C. Organ Failure
     1. Colifrom bacteria)
  D. Air Conditioner Contamination
     1. Legionella
  E. Airway Obstruction
     1. Anerobic bacteria
  F. Corticosteroid use
     1. Yeast
  G. Neutropenia (<500 neutrophils/mm3)
     1. Aspergillus
     2. candidiasis

III. Symptoms
  A. Fever
  B. Cough with purulent sputum
  C. Chest pain-sharp pain increases on inspiration and coughing
The clinical diagnosis of pneumonia has classically been made on the basis of a combination of fever, leukocytosis, cough, purulent sputum which grows pathogens on culture, and a new or worsening radiographic infiltrate. Associated findings include pleuritic chest pain and worsening oxygenation. In critically ill or hospitalized patients, all of these findings can be caused by multiple other diagnoses, infectious and noninfectious, pulmonary or nonpulmonary. The two most critical clinical criteria localizing the source to the lung are purulent secretions and radiographic infiltrates.

IV. Labs
  A. C B C
     Shows Leucoctosis
  B. Blood Gas
     Results show increased A-a gradient

V. Radiology:
X ray chest shows new or progressive lung infiltrate

VI. Bronchoscopic Diagnosis
Because the inaccuracy of clinical diagnosis and tracheal aspirate cultures has been recognized, several techniques have been developed to increase the accuracy of the microbiologic diagnosis. The common denominators in all attempts to improve the microbiologic diagnosis of pneumonia involve lower respiratory tract, rather than tracheal, sampling, and quantitative culture of the secretions obtained. Quantitative cultures are important to distinguish the inevitable low-level contamination of passing through either the upper airway or the endotracheal tube.
The most extensively studied techniques have been bronchoscopy with the PSB and BAL. The techniques of performing each have been standardized. Variants of these two techniques include single-sheathed brushes, protected BAL, and mini-BAL through a sheath.
Bronchoscopic techniques clearly have an advantage over clinical diagnosis in specificity. The specificity of both BAL and PSB has been estimated to be as high as 90%.

VII Management: Antibiotics
  A. Imipenem 0.5 g IV q6 hours
  B. Meropenem 1.0 g IV q8 hours
  C. Combinations (2-3 antibiotics)
    1. Antibiotic 1: Aminoglycoside Options
       a. Gentamicine
       b. Tobramycin 5 mg/kg IV q24 hours
    2. Antibiotic 2 Options
       a. Ceftazadime 2 g IV q8 hours
       b. Piperacillin 4 g IV q6 hours
       c. Ticaricillin 4 g IV q6 hours
    3. Antibiotic 3 (consider)
       a. Clindamycine 450-900 mg IV q8 hours
   D. Cifrofloxcine Combinations (2 antibiotics)
  
Antibiotic 1
      a. Cifrofloxcine 400 mg IV q12 hours

Antibiotic 2
      b. Ticarcillin 3.1 grams IV q6h
      c. Piperacilline -Tazobactam (Zosyn) 3.375 g IV q6 hours
   E. Organisms requiring additional antibiotic coverage
    1. Methicilline resistant staphylococcus aurius
      a. Vancomycine 1 gram IV q12 hours given over 1 hour
    2. Legionella
      a. Azithromycine 500 mg IV q24 hours or
      b. Broad spectrum Fluoroqinolines
           i. Trovafloxacin 300 mg IV q24 hours
           ii. Levofloxacin 500 mg IV q24 hours
    3. Fungal Organisms
     a. Amphotericin B

VIII. Risk factors and suggested infection-control measures for preventing nosocomial pneumonia

Disease/Risk factors	Suggested infection-control measures
Bacterial pneumonia Host-related (persons aged >65 yrs) Underlying illness:
Chronic obstructive pulmonary disease	Perform incentive spirometry, positive end-expiratory pressure, or continuous positive airway pressure by face mask.
Immunosuppression	Avoid exposure to potential nosocomial pathogens; decrease duration of immunosuppression (e.g., by administration of granulocyte macrophage colony stimulating factor GMCSF|).
Depressed consciousness	Administer central nervious system depressants cautiously.
Surgery (thoracic/ abdominal)	Properly position patients; promote early ambulation; appropriately control pain.
Device-related	Properly clean, sterilize or disinfect, and handle devices; remove devices as soon as the indication for their use ceases.
Endotracheal intubation and mechanical ventilation	Gently suction secretions; place patient in semirecumbent position (i.e., 30 degrees-45 degrees head elevation); use nonalkalinizing gastric cytoprotective agent on patients at risk for stress bleeding; do not routinely change ventilator circuits more often than every 48 hours; drain and discard inspiratory- tubiing condensate, or use heat- moisture exchanger if indicated.
Nasogastric-tube (NGT) placement and enteral feeding	Routinely verify appropriate tube placement; promptly remove NGT when no longer needed; drain residual; place patient in semirecumbent position as described as above.
Personnel- or procedure-related Cross-contamination by hands	Educate and train personnel; wash hands adequately and wear gloves appropriately; conduct surveillance for cases of pneumonia and give feedback to personnel.
Antibiotic administration	Use antibiotics prudently, especially in patients in intensive-care units who are at high risk.
Host-related
Immunosuppresion	Decrease duration of immunosuppression.
Device-related
Contaminated aerosol from devices	Sterilize/disinfect aerosol-producing devices before use; use only sterile water for respiratory humidifying devices; do not use cool- mist room-air humidifiers without adequate sterilization or disinfection.
Environment-related
Aerosols from contaminated water supply	Hyperchlorinate or superheat hospital water system; routinely clean water-supply system; consider use of sterile water for drinking by immunosuppressed patientes.
Cooling-tower draft	Properly design, place, and maintain cooling towers.
Aspergillosis Host-related
Severe granulocytopenia	Decrease duration of immunosuppresion (e.g., by administration of GMCSF); place patients who have severe and prolonged granulocytopenia in a protected environment.
Environment related
Construction activity	Remove granulocytopenic patients from vicinity of construction; if not already done, place severely granulocytopenic patients in a protected environment; make severely granulocytopenic patients wear a mask when they leave the protected environment.
Other environmental sources of aspergilli	Routinely maintain hospital air- handling systems and rooms of immunosuppressed patients.
Respiratory syncytial virus infection (RSV)
Host-related
Persons ages <2 yrs;
congenital pulmonary/cardiac disease; immunosuppression	Consider routine preadmission screening of high-risk patients for severe RSV infection, followed by cohorting of patients and nursing personnel during hospital outbreaks of RSV infection.
Personnel- or procedure-related
Cross-contaminated by hands	Educate personnel; wash hands; wear gloves; wear a gown; during outbreaks, use private rooms or cohort patients and nursing personnel, and limit visitors.
Influenza
Host-related
Persons ages >65 yrs; immunosuppresion	Vaccinate patients who are at high risk before the influenza season begins each year; use amantadine or rimantadine for chemoprophylaxis during an outbreak.
Personnel-related
Infected personnel	Before the influenza season each year, vaccinate personnel who provide care for high-risk patients; use amantadine or rimantadine for prohylaxis and treatment during an outbreak.