Module 6 - Infection Flashcards
External Risk Factors
operating room (ventilation, sterilization)
contaminated equipment
improper hand hygiene
Procedural Risk Factors
infection at remote site not treated prior to surgery
inappropriate antimicrobial prophylaxis & skin prep (shaving vs. clipping)
improper technique (sterile field, foreign bodies)
contaminated hardware
Patient Risk Factors
immunocompromised
diabetes
5 W’s of infection
wind - lungs/GIT water - urinary wings - limbs/hardware/tubes/lines/drains wound - incision wonder drugs - corticosteroids
Types of antibiotics
naturally derived
synthetically derived
Antibiotics
drugs that kill bacteria
Antimicrobials
any drug that targets microbes other than bacteria
Antibiotic MOA
bacteriostatic or bactericidal
Bacteriostatic
slows bacterial growth
Bactericidal
kills bacteria
Narrow spectrum abx
work on a subset of bacteria
Broad spectrum abx
work on a range of bacteria
Beta-lactam drugs (cell wall inhibitors)
penicillins
cephalosporins
carbapenams
monobactams
Other cell wall inhibitors
vancomycin
bacitracin
Mechanisms of microbial resistance
1) decreased penetration
2) increased enzymatic degradation/modification
3) alteration of target site
4) increased efflux (removal)
Lactam drugs mechanism of resistance
beta-lactamase breaks down the lactam ring
Multidrug resistance
bacteria develop molecular pumps to actively remove antibiotics out of cell
VRE mechanism of resistance
alter peptidoglycan synthesis so that antibiotic does not bind
MRSA mechanism of resistance
uses altered PBP so B-lactam can’t bind
Factors promoting bacterial resistance
1) fast evolution
2) bacteria can share DNA
3) antibiotic overuse –> increase abx resistant strains
Nursing antibiotic stewardship
1) reduce need for abx –> hygiene, vaccines, safe sex
2) validate infections before beginning abx treatment
3) use abx exactly as prescribed –> complete entire regiment
4) patient reassessment within 48 hrs
How long after abx should a pt be reassessed?
48 hrs
Most common bacteria causing UTI
Uropathogenic e. coli
Uncomplicated UTI risk factors
female gender
older age
younger age
Complicated UTI risk factors
indwelling catheters
immunosuppression
UTI abnormalities
abx exposure
Mechanisms of UTI infection
1) fecal bacteria (ascending)
2) sexual contact
3) contaminted diaphram/birth control
4) can occur from the blood
Recurrent UTI MOA
once uropathogenic enter the urethra they can colonize the epithelium –> recurrent infection
Estrogen & Immunity
estrogen promotes production of glycogen
lactobacilli digest glycogen –> lactic acid + bacteriocidal compounds
lactic acid = reduce urethral pH
bacteriocidal = kills bacteria
UTI Risk Factors
obstruction reflux congenital abnormalities female sex menopause urinary retention/urinary stasis neurologic abnormalities immunosuppression catheterization / cystoscopy inflammation/abrasion of urethral mucosa diabetes --> hyperglycemia prostate disorders
Factors causing urinary retention/stasis
diverticulitis
bladder tumors
contracture of bladder neck
Urine collection steps
collect adequate amount 10-20 cc PRIOR to abx therapy
use a sterile container –> label
use aseptic technique –> clean catch, foley catheter
transport promptly to lab or fridge
Direct analysis of pathogen
phenotype
genotype
serotype
Indirect analysis of pathogen
serology –> look for specific antibodies made in response to infection
Microscopic tests
gram stain
Biochemical test
catalase enzyme
Growth conditions
O2 requirement of bacteria
aerobic vs. anaerobic
Elevated neutrophils
acute bacterial infection
Elevated lymphocytes
viral infection
Elevated eosinophils
allergic/parasitic infection
Elevated basophils
food allergy
Immature granulocytes
leukemia/lymphoma
Lab tests for UTi
Urine dipstick
Microscopy
Culture & Sensitivity
What does a urine dipstick measure
leukocyte esterase –> indicates WBC in urine
nitrites –> bacterial byproduct
Pyuria
presence of WBC in urine
>5-10
Hematuria
presence of blood in urine
How long does a C&S take
2-3 days
Systemic S/S of infection
fever
hypotension
fatigue
UTI Classification
upper vs. lower
complicated vs. uncomplicated
acute, chronic, recurrent
Upper UTI
kidneys
ureters
Lower UTI
bladder
urethra
Urinalysis components
colour specific gravity pH blood protein glucose nitrite leukocyte esterase bacteria WBC
Antibiotic patient education
take full dose, complete entire regimen may need to take with food (GI upset) may cause adverse fx follow prescription orders carefully report any adverse fx to your doctor
Common adverse fx of antibiotics
nausea/vomiting diarrhea rash urticaria photophobia fever chills
UTI Prevention
increase fluids (2L daily) void frequently (every 2-3 hrs) proper hygiene (wipe front to back) void after intercourse drink cranberry/blueberry juice
Immune defenses
washout phenomenon antibacterial enzymes antibodies (IgA) antiadherent fx of mucosal cells ureterovesicle junction (prevent reflux) bladder mucin layer (water barrier) prostate secretions normal bacterial flora of urethra
Washout phenomenon
urine sweeps away bacteria in the urethral tract
Urinary reflux
occurs when urine backflows from urethra –> bladder or bladder –> kidneys
What causes urinary reflux?
sudden increase in intra-abdominal pressure
suddenly stopping urinary stream
common in children
Routes of infection
ascending (most common)
thru bloodstream
fistula form intestine
S/S of lower UTI
pain burning on urination frequency urgency nocturia incontinence suprapubic/pelvic pain hematuria
S/S of upper UTI
flank pain (costovertebral palpation) chills fever N/V headache malaise painful urination
S/S of UTI in Older Adults
fatigue delirium sudden onset confusion altered sensorium anorexia new incontinence hyperventilation low grade fever
Urine characteristics
volume color concentration cloudiness odour
Strategies to reduce CAUTI
aseptic technique
use smallest catheter possible
secure catheter w/ tape to prevent movement/irritation
inspect urine
daily perineal care
maintain closed system (foley catheter bag)
Normal PVR
50-100 mL
Types of urinary obstruction
functional
mechanical
Mechanical urinary obstruction
renal/ureteral calculi
BPH
pregnancy
malformation of ureterovesical junction
Functional urinary obstruction
neurogenic bladder decreased voiding detrusor instability (anticholinergic drugs) constipation
