<prompt> True about Pneumocystis carinii Pneumocystis jerovecii is the following EXCEPTRespiratory alkalosisdiffusion capacityCyanosisarterial O2 gradient PAO2 - PaO2  <response>: Ans. d arterial O2 gradient PAO2-PaO2 Ref: Harrisons Internal medicine 17th edition, p. 1267ABG in PCP: alveolar arterial O2 gradient Normal 15 mm H2O 20-30 PaO2 When,When,PAO2 - PaO2 35 mm Hg:- PAO2 - PaO2 35 mm Hg and PaO2 60 mm Hg:- Mild infection- Severe infection- No need to add steroids- Add steroid for 14-21 days.Pneumocystis JiroveciiFungus - Ribosomal genetic make-up and RNA resembles to that of fungus, but lacks mycolic acid in cell-wall. When it occurs? -CD4 count 200mcc in HIV patients When to suspect? -Fever 2 weeksDry cough 2 weeksPresence of oropharyngealoesophageal Candida Clinical features: Dry cough, Dyspnea, Tachycardia, Fever, Cyanosis RS examination: Auscultation reveals only few abnormalities CXR: Most common reticulonodular infiltrates starting at hillum involving MZ and LZ with sparing of apex and CP angle perihilar ground-glass haziness is earliest radiological change in PCP. Rarest - pleural effusion. Pneumothroax especially receiving 5-10 cases aerosolized pentamidine. Diffusion capacity of lung Other sites of P Jirovecii infection- Lymph node most common extrapulmonary site0- Spleen- Liver- Bone Marrow Treatment- DOC - Septran- Other Drugs: Dapsone, Pentamidine, Clindamycin and Atovaquone.Summary - Pneumocystis jirovecii: Yeast originally classified as protozoan. Inhaled. Most inf asymptomatic. Immunosuppression AIDS pre- disposes. Causes Pneumocystis pneumonia PCP, a diffuse interstitial pneumonia. Diffuse, bilateral CXR appearance. Diagnosed by lung biopsy or lavage. Disc-shaped yeast forms on meth- enamine silver stain of lung tissue. Treatmentprophylaxis: TMP-SMX, pentamidine, dapsone prophylaxis only, atovaquone prophylaxis only. Start prophylaxis when CD4 count drops 200 cellsmm3 in HIV patients.Also Know:Conditions where diffusion capacity of Lung increasedEarly LVFIntra-alveolar hemorrhage 