Infectious Disorders

Question 1

Antibiotic Resistance

Answer 1

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

Question 2

Penicillin

Answer 2

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

Question 3

Surgical Site Infections (SSIs)

Answer 3

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

Question 4

SSI Prevention

Answer 4

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

Question 5

Bloodstream Infections

Answer 5

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

Question 6

Internal Jugular Vein

Answer 6

R 15cm

L 18cm

Question 7

Subclavian Vein

Answer 7

R 14cm

L 17cm

Question 8

Clostridium Difficile

Answer 8

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

Question 9

Necrotizing Soft Tissue Infection

Answer 9

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

Question 10

Necrotizing Anesthesia Management

Answer 10

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

Question 11

Tetanus

Answer 11

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

Question 12

Pneumonia

Answer 12

Community-acquired
Aspiration (anesthesia related)
Postoperative
Ventilator-assisted

Question 13

Pneumonia S/S

Answer 13

Fever, chest pain, dyspnea, fatigue, rigors, cough, sputum production
Patient history - travel, cave exploration, diving contact w/ birds/sheep, immunocompromised
Chest radiograph
+ cultures
↑WBCs

Question 14

Pneumonia Prevention

Answer 14

CDC recommends PPSV23 vaccine all adults >65yo

Question 15

Pneumonia Anesthesia Management

Answer 15

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

Question 16

Severe Acute Respiratory Viral Illness

Answer 16

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

Question 17

Viral Infections Treatment

Answer 17

Prevent spread
Vaccines when available
Neuraminidase inhibitors (Tamiflu) - only given w/in first 48hrs S/S
1° supportive care

Question 18

Anesthesia Management

Answer 18

LPV & symptom management
Barrier precautions
Filters place on breathing circuit
Clean room w/ alcohol
Wait 48hr until another case

Question 19

Operating Rooms

Answer 19

All ORs are positive pressure rooms

Question 20

Negative Pressure

Answer 20

Minimum recommendation total 15 air exchanges per hour w/ minimum 3 air changes outdoor air per hour
Isolation rooms need an anteroom

Question 21

Ultraviolet Germicidal Irradiation

Answer 21

Different wavelength types
UV-C (germicidal UV)
Installed into HVAC systems
Needs direct light to the surface
Burns possible

Question 22

HEPA Filters

Answer 22

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

Question 23

HMEF

Answer 23

Heat & moisture exchange medium together w/ electrostatic filter

Question 24

Tuberculosis

Answer 24

Mycobacterium tuberculosis - aerobe

Survives most successfully in tissues w/ high oxygen concentrations (pulmonary & extrapulmonary)

Question 25

Tuberculosis S/S

Answer 25

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

Question 26

Tuberculosis Treatment

Answer 26

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

Question 27

Acquired Immunodeficiency Syndrome

Answer 27

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

Question 28

Pneumocystis Pneumonia

Answer 28

CD4 count <200 cells/mL

Question 29

AIDS

Answer 29

Nucleic acid testing HIV RNA most specific & sensitive test

Diagnosis defined when HIV+ patient has one AIDS defining diagnosis present

Question 30

AIDS Anesthetic Considerations

Answer 30

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

Question 31

Prions

Answer 31

Proteinaceous infective particles are infectious proteins w/o known nucleic acid genomes
Preferentially target neurologic tissue causing spongiform encephalopathies
Neurodegenerative diseases are universally lethal

Question 32

Standard Precautions

Answer 32

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

Question 33

Contact Precautions

Answer 33

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

Question 34

Enhanced Barrier Precautions

Answer 34

Expand PPE use beyond situations when exposure to blood & bodily fluids anticipated
Care activities requiring gown & glove - toilet, airway, & wound care

Question 35

Droplet Precautions

Answer 35

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

Question 36

Airborne Precautions

Answer 36

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)