Infectious Disorders Flashcards
Antibiotic Resistance
When germs (bacteria & fungi) develop the ability to defeat the drugs designed to kill them Bacteria have become resistant to the antibiotics designed to kill them Multidrug-resistant (MDR) organisms are responsible ↑number hospital-acquired infections
Penicillin
β-lactam antibiotic Penicillin G (IV) destroyed by stomach acid Penicillin V (PO) semi-synthetic True PCN allergy IgE <1% 10% crossover b/w PCNs & cephalosporins
Surgical Site Infections (SSIs)
20% intra-abdominal
15% nosocomial (hospital-acquired infections)
2-5% extra-abdominal surgeries
*Occurs w/in 30days surgery or w/in 1yr prosthetic implant or organ
SSI Prevention
Preoperative antibiotics Glycemic control <500mg/dL Maintain normothermia Optimize oxygenation Antimicrobial soap bath prior to surgery Intraop skin prep w/ an alcohol-based antiseptic agent
Bloodstream Infections
Nosocomial bloodstream infections r/t central venous catheters
Catheter-associated bloodstream infection defined as bacteremia or fungemia in patient w/ IV catheter & at least one positive blood culture obtained from peripheral vein
Internal Jugular Vein
R 15cm
L 18cm
Subclavian Vein
R 14cm
L 17cm
Clostridium Difficile
C Diff
Spore-forming bacteria
Antibiotic-associated diarrhea & pseudomembranous colitis d/t toxin A & B production
Megacolon → colectomy & ileostomy
Treatment: remove causative antibiotic & oral antibiotics
Hemodynamic instability
Contact & isolation precautions
Handwashing to remove spores
Bleach germicidal wipes on equipment/room
Necrotizing Soft Tissue Infection
Mortality up to 75%
- Gas gangrene, toxic shock syndrome, Fournier’s gangrene, severe cellulitis, flesh-eating infection
- General infection, atypical measles syndrome, pain
- Infection begins in deep tissue
Necrotizing Anesthesia Management
Resuscitation
Septic & fluid shifts
Do not delay surgical treatment
Hemodynamic instability d/t cytokines release
Ensure adequate IV access, A-line, central venous catheter, blood products available
Multi-organ failure risk → ICU
Tetanus
Neurotoxin tetanospasmin from clostridium tetani organisms
Suppresses inhibitory spinal cord neurons → generalized skeletal muscle contractions
Treatment includes benzodiazepines & muscle relaxants to control skeletal muscle spasm
- Neutralize exotoxin (human anti-tetanus immunoglobulin)
- Penicillin
Pneumonia
Community-acquired
Aspiration (anesthesia related)
Postoperative
Ventilator-assisted
Pneumonia S/S
Fever, chest pain, dyspnea, fatigue, rigors, cough, sputum production
Patient history - travel, cave exploration, diving contact w/ birds/sheep, immunocompromised
Chest radiograph
+ cultures
↑WBCs
Pneumonia Prevention
CDC recommends PPSV23 vaccine all adults >65yo
Pneumonia Anesthesia Management
Delay surgery during acute pneumonia Avoid fluid overload LPV often PEEP dependent Consider same ventilator settings as ICU Lowest inspired oxygen possible Suctioning Maintain antibiotic/antiviral/antifungal schedule
Severe Acute Respiratory Viral Illness
Highly virulent w/ high mortality
H5N1 influenza A “bird flu”
Coronavirus strains (MERS, SARS-CoV, COVID-19)
Non-specific S/S fever, headache, diarrhea, respiratory distress, hemoptysis
Precautions: airborne, droplet, or contact
Viral Infections Treatment
Prevent spread
Vaccines when available
Neuraminidase inhibitors (Tamiflu) - only given w/in first 48hrs S/S
1° supportive care
Anesthesia Management
LPV & symptom management Barrier precautions Filters place on breathing circuit Clean room w/ alcohol Wait 48hr until another case
Operating Rooms
All ORs are positive pressure rooms
Negative Pressure
Minimum recommendation total 15 air exchanges per hour w/ minimum 3 air changes outdoor air per hour
Isolation rooms need an anteroom
Ultraviolet Germicidal Irradiation
Different wavelength types UV-C (germicidal UV) Installed into HVAC systems Needs direct light to the surface Burns possible
HEPA Filters
High-efficiency particulate air filters
Theoretically remove at least 99.97% dust, pollen, mold, bacteria, & any airborne particles w/ size 0.3 microns
Inspiratory & expiratory on AGM breathing circuits
HMEF
Heat & moisture exchange medium together w/ electrostatic filter
Tuberculosis
Mycobacterium tuberculosis - aerobe
Survives most successfully in tissues w/ high oxygen concentrations (pulmonary & extrapulmonary)
Tuberculosis S/S
Cough, anorexia, weight loss, night sweats, chest pain
Chest radiographs show apical or subapical infiltrates or bilateral upper lobe infiltration w/ presence cavitation
Tuberculosis vertebral osteomyelitis (Pott’s disease) common manifestation extrapulmonary TB
Most common test = Mantoux’s skin test
Tuberculosis Treatment
Resistant to 2nd line therapeutic agents - fluoroquinolones & at least one injectable (amikacin, kanamycin, or capreomycin)
Chemotherapy w/ Isoniazid
Delay case until treatment possible
Negative pressure rooms
Patients & staff wear N95
HEPA filter
Caution to avoid spine injury during airway manipulation
Acquired Immunodeficiency Syndrome
Acute seroconversion illness occurs w/ high viral load soon after infection
↓viremia as patient immune response stimulated
Lymph node involvement → T-helper lymphocytes ↓CD4 T cells & ↑viral load
Pneumocystis Pneumonia
CD4 count <200 cells/mL
AIDS
Nucleic acid testing HIV RNA most specific & sensitive test
Diagnosis defined when HIV+ patient has one AIDS defining diagnosis present
AIDS Anesthetic Considerations
Patients subject to long-term metabolic complications including lipid abnormalities & glucose intolerance → diabetes, CAD, cerebrovascular disease
Focal neurologic lesions ↑ICP precluding neuraxial anesthesia
Neurological involvement - Succinylcholine hazardous
Prions
Proteinaceous infective particles are infectious proteins w/o known nucleic acid genomes
Preferentially target neurologic tissue causing spongiform encephalopathies
Neurodegenerative diseases are universally lethal
Standard Precautions
Applies to all patient care
Regardless suspected or confirmed infection or colonization status
Hand hygiene, safe injection practices, respiratory hygiene & cough etiquette, environmental cleaning & disinfection, & reprocessing reusable medical equipment
Contact Precautions
Known or suspected infections that represent an ↑risk contact transmission
Transmission-based precaution are used when pathogen transmission not completely interrupted by standard precautions alone
Gown & gloves
Dedicated equipment
Private room when possible
Norovirus, C difficile, scabies, MSSA, MRSA
Enhanced Barrier Precautions
Expand PPE use beyond situations when exposure to blood & bodily fluids anticipated
Care activities requiring gown & glove - toilet, airway, & wound care
Droplet Precautions
Pathogens transmitted via respiratory droplets that are generated when patient coughs, sneezes, or talks
Meningitis, petechial rash w/ fever, RSV, adenovirus, influenza, SARS-CoV, avian influenza
Airborne Precautions
Known or suspected to be infected w/ pathogens transmitted via airborne route
TB, measles, chickenpox, disseminated herpes zoster, varicella-zoster, herpes simplex, smallpox, rubeola (measles)
