B-lactam antibiotics

1.Penicillin

*Cr=50 ml/min(50~75%), 10 ml/min(25~33%)

*Carboxy-PCN- Fluid overload, Platelet↓

*B-lactamase- MSSA → Oxacillin

*PBP change- MRSA, PRSP → vancomycin


2. Cephalosporins

*AmpC B-lactamases- E.coli, K.p → Cefepime, Cefpirome, Imipenam, meropenam

*ESBL B-lactamases- E.coli, K.p → Imipenam, Meropenam, Cephamycin

*Serine/Metallo-B-lactamse- MDRAB → Tigecycline

*Cefoperazone and ceftriaxone– Liver metabolism


3.Carbapenams

*Imipenam → seziure


4.Monobactam


Necrotizing fasciitis / myositis / cellultis

Necrotizing fasciitis 

Site- Muscle fascia and  subcutaneous fat, muscle tissue is spared

Lab- CK↑

CT- Blurring fascia

1.Polymicrobial (type I)

-Older adult, DM, comorbidities

-Anaerobic species (most commonly Bacteroides, Clostridium, or Peptostreptococcus) +  Enterobacteriaceae (eg, Escherichia coli, Enterobacter, Klebsiella, Proteus) + facultative anaerobic streptococci (other than group A Streptococcus [GAS])

-Fournier gangrene(Perineum)-  facultative organisms (E. coli, Klebsiella, enterococci) + anaerobes (Bacteroides, Fusobacterium, Clostridium, anaerobic or microaerophilic streptococci) 

-Necrotizing infection of the head and neck – mouth anaerobes (such as Fusobacteria, anaerobic streptococci, Bacteroides, and spirochetes). Ludwig’s angina (submandibular space infection, trismus) and Lemierre syndrome (septic thrombophlebitis of the jugular vein).

2.Monomicrobial infection (type II)

-GAS or other beta-hemolytic streptococci, Staphylococcus aureus, Vibrio vulnificus and Aeromonas hydrophila



Necrotizing myositis

Pathogen- Group A Streptococcus (and other beta-hemolytic streptococci)


Necrotizing cellulitis 

Pathogen- Anaerobic pathogens 

1.Clostridial- Clostridium perfringens, Clostridium septicum

2.Non-clostridial- Polymicrobial infection

Skin infection

Pathway- Epidermis→ upper dermis→ deep dermis→ subcutaneous fat→ fascia→ muscle

Risk factor- Trauma, skin inflammation, edema due to impaired venous/lymphatic return, obesity, immunocompromised, skin infection

Type

1.Impetigo

Site- Epidermis


2.Erysipelas

Site- Upper dermis 

Pathogen- Beta-hemolytic streptococci

Characteristics- Clear demarcation between involved and uninvolved tissue, butterfly” involvement of the face. Involvement of the ear (Milian’s ear sign)


3.Cellulitis

Site- Deeper dermis and subcutaneous fat

Pathogen- Beta-hemolytic streptococci, Staphylococcus Aureus, H.Influenza

Treatment- Newborn → ampicillin+3rd cephalosporin, <5y/o →3rd cephalosporin, Adult→oxacillin, Immunocompromised →oxacillin+aminoglycoside


4.Skin abscess

Site- Collection of pus within the dermis or subcutaneous space

Pathogen- S.Aureus


Complication- Bacteremia, endocarditis, osteomyelitis, metastatic infection, sepsis, and toxic shock syndrome

Meningitis

Pathogen

1.Newborn- Group B streptococcus, E.coli, Listeria

2.1~3 m/o- Group B streptococcus, E.coli, Listeria, salmonella, H.Influenza, Neisseria, S.pneumonia

3.3 m/o~12 y/o- H.Influenza, Neisseria, S.pneumonia

4.>12 y/o- Neisseria, S.pneumonia


Presentation- Bulging Fontanelle, neck stiffness, Kernig sign, Brudzinski sign, Tripod sign

Treatment- 3rd cephalosporin + vancomycin, add ampicillin if want to cover Listeria

Duration- Neisseria(7 days), H.influenza, S.pneumonia(14 days), Listeria, Group B streptococcus(21 days)

CSF study

Lung cancer

Type

1.Adenocarcinoma

Site- Peripheral

Gene- Ras

2.Squamous cell carcinoma

Site- Central

Characteristic- Central necrosis, cavitation, keratinization, stratification, intercellular bridge formation, Pancoast tumor

3.Large cell undifferentiated carcinoma

Site- Peripheral

Pathology- Anaplastic pleomorphic cells

4.Small lung cell cancer

Site- Central


Paraneoplastic syndrome

1.Adenocarcinoma- Hypertrophic pulmonary osteoarthropathy(HPO), migrating thrombophlebitis, NBTE

2.Squamous- HyperCa, Horner syndrome3.Small- SIADH, Cushing syndrome, Eaton Lambert syndrome, polyneuropathy


Treatment

a)Non-small cell lung cancer (NSCLC)

1.Stage I→ Surgery

2.Stage II→ Surgery + chemotherapy

3.Stage IIIA→ Neoadjuvant C/T + surgery

4.Stage IIIB & IV→ First line(Cisplatin + Pemetrexed/Gemcitabine/Vinorelbine/Paclitaxel + Bevacizumab(adenocarcinoma)), Second line(Gefitinib, Erlotinib)

*Good factor of TKI- Exon 19(L747-S752 deletion, E746-A750 deletion), Exon 21 L858R→ Asian female, non-smoker

*Poor factor of TKI- Exon 20 T790M


b)Small cell lung cancer (SCLC)

*PCI- Prophylactic cranial irradiation

Pleural effusion

Light Criteria(exudates if meet>= 1criteria)- Pleural protein/serum protein>0.5, Pleural LDH/serum LDH>0.6, Pleural LDH>200

Protein-TB(>4.0),  Waldenström’s macroglobulinemia and multiple myeloma(7.0~8.0)

LDH >1000- Empyema, rheumatoid pleurisy, and pleural paragonimiasis, Pleural/Serum>1.0 & pleural/serum protein<0.5(PJP, malignancy)

TG- Chylothorax(>110)

Glucose <60 or pleural/serum<0.5→ Rheumatoid, TB, empyema, malignancy, Lupus pleuritis, esophageal rupture

PH- <7.30→ empyema, malignancy, rheumatoid pleurisy, and tuberculous pleurisy, pleuritis, pleural fibrosis

Amylase- pancreatitis, malignancy, esophageal rupture, pneumonia, ruptured ectopic pregnancy, hydronephrosis, and cirrhosis

ADA- >40(TB), <40(malignancy)

Lymphocytosis >85~95%→ tuberculous pleurisy, lymphoma, sarcoidosis, chronic rheumatoid pleurisy, yellow nail syndrome, or chylothorax), >50~70(malignancy)

Eosinophilia >10%→ Pneumothorax, Hemothorax, Pulmonary infarction, Benign asbestos pleural effusion, Parasitic disease, Fungal infection (coccidioidomycosis, cryptococcosis, histoplasmosis), Malignancy (carcinoma, lymphoma, myeloma), Tuberculous pleurisy, Parapneumonic effusions, Chronic eosinophilic pneumonia)

Mesothelial cell- >5%(not TB), <1%(TB)

Acute respiratory distress syndrome (ARDS)

Berlin definition

1.Acute onset(< 24hrs)

2. Bilateral opacities

3. No cardiac failure, PAWP<18 mmHg

4. 300 mmHg ≥PaO2/FiO2 >200 mmHg(mild),  200 mmHg ≥PaO2/FiO2 >100 mmHg(moderate),  PaO2/FiO2 ≤100 mmHg(severe), all with PEEP ≥5 cm H2O.

Etiology

Stage

ARDS vs Heart failure pulmonary edema

Ventilation strategy

Aspergillosis

Toxin- Aflatoxin, orchratoxin, fumagillin, gliotoxin

Type

1.Aspergilloma(Most common)

ForewordLung cavitation already present

X-ray- Monod sign(Radiopaque lesion surrounded by radiolucency)

Treatment- Amphotericin B, voriconazole


2.Allergic bronchopulmonary aspergillosis(ABPA)

Foreword- Accompanied with asthma, Th2↑

Diagnostic criteria(Major criteria)

CT- Central bronchiectasis

Treatment- Steroid, Itraconazole


3.Invasive aspergillosis

Forewaord- Immunocompromised patient

CT- Halo sign, ground glass, Air crescent

Treatment- Hematopoietic growth factors, Voriconazole


4.Chronic necrotizing aspergillus pneumonia

Foreword- Th1↓, lung fibrosis, Cavitary pneumonia

Treatment- Itraconazole

Bronchiectasis

Etiology- Cystic fibrosis, Alpha-1 antitrypsin deficiency, selective Ig A deficiency, ABPA, Sjogren syndrome, Kartagener’s syndrome(sinusitis, bronchiectasis, situs inversus, hypomotile cilia), Obstruction(carcinoid tumor), Bacteria(SP, HI, KP, SA, pertussis, TB), Virus(Measles, Influenza, VZV, adenovirus)

Presentation- Cough with sputum

Pathogen- H.influenza, Pseudomonas, Streptococcus

Image- Signet ring sign, dot ring sign, tram tracks, ring shadow

Complication- Lung, brain abscess