Hospital-acquired pneumonia:
Dr. moshtak wtwt FIBMS
()Definition: refers to pneumonia that occurs ?48 hours after admission, which was not incubating at the time of admission. , post-operative pn., or nosocomial pn or ventilatory ass pn, health care ass pn. Early-onset HAP within the first 4 days of hospitalization. Late-onset HAP and VAP: 5 days or more of hospitalization.
() incidence: *2nd most common nosocomial infection *Rate 5-15 cases/ 1000 hospital admission *? 6- to 20-fold in mechanically ventilated patients *Increases hospital stay by 7-9 days / patient *Mortality rate is seriously high 30- 50 %
()Factors predisposiong to HAP: *age>70 years, female sex. *chronic lung diseases. *h2 blockers or antacids, cs. *dm, malignancy. *post-operative. *bulbar or vocal cord palsy. *unconscoius. *vomiting, achalasia, dysphagia. *ng tube, tracheostomy, bronchoscope. *dental or sinus infection.
*bactereamia: abdominal sepsis, iv cannula, infected emboli
organisms
Bacterial ( 80-90%):
- Gram –ve bacilli (50-70%)
Pseudomonas aeruginosa
Enterobacteriaceae
Staphylococcus aureus (15-30%)
Anaerobic bacteria (10-30%)
Haemophilus influenzae (10-20%)
Streptococcus pneumoniae (10-20%)
Legionella speecies (4%)
Viral (10-20 %)
- Cytomegalovirus
- Influenza
- Respiratory syncytial virus
Fungal (< 1%)
()Pathogenesis: 1-aspiration is play a central role. 2-polymicrobial, mostly g- negative bacilli (nosopharynx), 3-together with poor host defenses, very ill pateints or semiconscious so unable to clear upper airways & resp tract secretions.
()Clinical Features: *symptomes of acute bronchitis, followed by increased cough, purulent sputum, fever, dyspnea & cyanosis then appear. (hypostatic pn) *o/e: sings of consolidation or cavitations. * CXR: mottled opacities in lower zones. ()diagnosis: should suspected in any pt admited to hospital after 2 days, which develop: *purulent sputum *new CXR infilterate *decrease O2 saturation *tem > 38 centigrade *leukocytosis or leukopenia ()management: *cefotaxime plus gentamycin. or *meropenuem. or *aztreonam plus flucloxacillin *O2, iv fluids.
()**LUNG abscess:(suppurative) ()Definition: is a form of pneumonia in which there is destruction of the lung parenchyma. suppurative pn: microabscess lung parenchyma. lung abscess: large collection of pus or cavity lined by chronic inflammatory tissue. either: primary lung abscess: infection of healthy lung tissue. secondary: infection of pul infarct, collapse, bullae, ()Organisms: primary: staph. aur, klebsiella pn. secondary: staph. aur, strep. pneum, h infleunzae, m. tuberc, bacteriod fragilis, MRSA
() Clinical Features: *Symptoms: -productive cough of large amount foul sputum. -pleural pain. -anorxia, vomiting, lossing wt. -fever, rigor, profuse sweating. *Signs: -high remittent fever. -tachypnea, hypotension, dyspnea. -digital clubbing. -signs of consolidation; signs of cavitations rarely found.
() Management: *in many pt oral Rx with amoxicillin is effective. *iv therapy is mandatory in moderate to severe cases. *can add oral metronidazol if susp of anaerobic inf. *if MRSA: oral with trimeth/sulpha, clindamycin, tetra, & linezolid. If paranteral: vancomycin *4-6 weeks duration of treatment. *physiotherapy is of great value. *surgical intervention indicated in: 1- failure to respond to medical treatment. 2- suspected neoplasm. 3- suspected hemorrhge. 4-large abscess > 6 cm 5- resistence organisms.