Ch_5 - Infectious Disease Flashcards
Below what temp is NOT a fever?
<38C (100.4F) is NOT a fever
T/F Persistent fever is more dangerous than a single elevation
True
Normal Rectal Temp can be __C (__F) (higher/lower) than oral temp
Normal Rectal Temp can be 0.5C (~1F) HIGER than oral temp
Fever + Hypotension/Tachycardia = ?
SIRS (danger)
Fever + Hypotension/Tachycardia + acidosis + confusion = ?
Likely Sepsis (worse danger)
Fever + Hypotension/Tachycardia + acidosis + confusion + AKI + lung failure = ??
Severe Sepsis (death is knocking)
Do not send a culture (except blood culture) without what?
evidence of infection
If a sputum culture grows Staph in a patient with pneumonia, what are the reasons for growing the Staph in the sputum culture?
- Contaminant from sloppy sample collection
- Colonization of mouth
- Colonization from endotracheal or tracheostomy tube.
- Possible PNA
If patient gets sepsis (fever + hypotension/tachycardia + confusion or metabolic acidosis, what should the patient get?
FLUIDS! – 500-1000 mL of NS
Blood cultures
and IV Antibiotics STAT!
Everyone with Unexplained fever needs (3)
Blood cultures (2 sets from different sites)
CXR
U/A
“Blood, lungs, and Urine”
If a patient presents with an obvious skin infection from cellulitis causing fever, does the pt need a UA?
No
Which cultures should you not do because they are useless or could be dangerous?
- No UCx unless UA shows WBCs
- No sputum Cx without a new infiltrate on CXR and pt produces no sputum.
- Do not swab a skin ulcer and send for Cx. Any ulcer will grow something, and they may not have caused the infection.
When NOT to do a Urine culture?
When UA shows no evidence of infection (eg, WBCs)
When not to do a sputum cx?
If there’s no infiltrate on CXR and pt doesn’t produce sputum
Should skin ulcer surfaces be swabbed and sent for culture?
No
What are the possible adverse consequences of unnecessary cultures?
- prolonged hospital stay
- giving antibiotics that have no benefits (but can harm)
- C. diff colitis diarrhea
- Resistant organisms
T/F Wound or Urine “colonization” should be treated with antibiotics
False, should not!
an elevated WBC count (leukocytosis) should be evaluated the same way as ???
Fever
A pt presents with an elevated white count. Now what?
1) look for/ask about a clear cause of infection (Urine, lung, skin are MC)
2) 2 blood Cx, UA, CXR
3) No UCx unless WBCs are in UA
4) No sputum Cx unless new infiltrate on CXR and sputum is produced
What about “pan-culture”
Don’t do it! The only thing you need for fever/high WBC is a blood culture (2). Do UCx only if UA is + for WBCs and no sputum culture unless indicated.
Urine culture done and shows E. coli and/or fungi. Now what?
if there’s no evidence of infection (eg, no WBCs on U/A) then don’t treat (exception is pregnant women).
E. coli growing from urine w/o WBCs or dysuria can be from?
- Colonization of Foley
- Contamination on urine collection
- “Clean catch” urine can be very hard to obtain in bedbound pts, esp women, demented.
blood cx can be contaminated with _____ from inadequate prep
skin bacteria (flora)
If blood cx grows an organism you have to make sure it’s…?
…a true infection and not a contaminant.
If blood cx grows an organism you have to make sure it’s a true infection and not a contaminant. How can one tell whether it’s a true infection (or limit the result to be of a contaminant?)
if same organism is grown from multiple sites (thus, taking at least 2 blood cx from MULTIPLE sites is key!)
the only routine culture in a febrile patient is…
a blood culture.
When should you suspect sepsis?
- Fever + hypotension + tachycardia
- Metabolic acidosis (pH < 7.2) w/ low HCO3
- Incr anion gap
- Resp alkalosis (compens) PCO2 <35
- high/low WBC (less important than acidosis and hypotension)
What should you order for a pt with sepsis?
blood cx
UA
CXR
Abx NOW! – don’t wait for lab results (can’t wait 1-2 days for blood cx results if pt is septic.
in addition to sepsis signs, what sx/sy would make you believe a pt is in severe sepsis?
organ dysfunction – renal, hepatic, CNS disturbance
Treatment of sepsis is ..
empiric (prior to culture results)
Is there one single treatment for all sepsis?
No
How do you generally empirically treat sepsis?
Vancomycin + 1 of the following
- Zosyn (pipercillin/tazobactam) or Timentin (Ticarcillin/Clavulanic acid)
- Carbapenem (DIM - Doripenem, Imipenem, Meropenem)
- Cefepime or Ceftazidime
How do you generally treat severe sepsis?
Tx of sepsis (eg, Vanc + Zosyn) + a second gram-negative agent:
- FQ
- Monobactam (Aztreonam)
- Aminoglycoside (Gentamicin, Amikacin, Tobramycin)
Name the commonly used FQs [4]
- Ciprofloxacin
- Levofloxacin
- Moxifloxacin
- Gemifloxacin
T/F Ciprofloxacin covers pneumococcus
False
Name the group of Abx that cover Gram-neg rods
FQs, some Penicillins, Cephalosporins, AGs, Monobactem (Aztreonam) and Carbapenems
Which 2 penicillin agents cover gram-neg rods?
Pipercillin, Ticarcillin
What must the 2 penicillin agents be combined with to cover for gram-neg rods?
a beta-lactamase inhibitor
Pipercillin - tazobactam
Ticarcillin - Clavulonate
What are the 4 commonly used Cephalosporins against gram-neg rods?
Ceftriaxone
Cefotaxime
Cefepime
Ceftazidime
What is considered the #1 Cephalosporin agent against pneumococcus?
Ceftriaxone
What are the 3 common aminoglycosides (AGs) used against gram-neg rods?
GTA
Gentamicin, Tobramicin, Amikacin
Should aminoglycosides be used as single agents against gram-neg rods?
No!
What is the common monobactem that is used against gram-neg rods?
Aztreonam
Which beta-lactam does not have cross-reaction with penicillin?
Aztreonam
What are the 4 carbapenems commonly used against gram-neg rods?
DIME
Doripenem, Imipenem, Meropenem, Ertapenem
Which carbapenem does not cover Pseudomonas?
Ertapenem
Pt has PCN allergy (rash only), can Ceph’s be used
yes
Staph and Strep commonly cause which diseases (organs)?
Bone/heart/skin/joint infections
What are the IV meds used against Staph aureus and Strep pyogenes?
IV Oxacillin, IV Nafcillin, IV Cefazolin (1st gen Ceph)
What are the Oral meds used against S. aureus and Strep pyogenes?
PO Dicloxacillin, PO Cephalexin
Oxacillin route of administration?
IV
Dicloxacillin route of administration?
PO
Nafcillin route of administration?
IV
Cefazolin route of administration?
IV
Cephalexin route of administration?
PO
What are the common gram-neg rods?
E.coli, Enterobacter, Pseudomonas, Citrobacter, Klebsiella, Proteus, Serratia, Morganella
Gram-neg rods often cause what diseases (organs)?
GI/UTI/Liver
Anaerobes often cause what diseases (organs)?
Abdominal/Lung, Abscesses
GI diseases 2/2 anaerobes are often tx w/ what meds?
Flagyl (Metronidazole)
Carbapenems
B-lactam/lactamase
Respiratory diseases 2/2 anaerobes are often tx w/ what meds?
Clindamycin
B-lactam/lactamase
Tigecycline covers ___ and ___
MRSA and G(-) rods
MRSA infection can be divided into 2 types…
Severe infections and minor localized infection
‘Severe’ MRSA = ??
Lung, Heart, CNS, Bacteremia
‘Minor localized’ MRSA = ??
Skin
Severe MRSA drug options
- Vancomycin
- Linezolid
- Daptomycin
- Tigecycline
- Ceftaroline
Minor localized MRSA drug options
- Bactrim (TMP/SMX)
- Clindamycin
- Doxycycline
- Linezolid
Common dangerous adverse effect of Linezolid?
Thrombocytopenia
Common dangerous adverse effect of Daptomycin?
CPK elevation
T/F Daptomycin is not effective in the lungs
True
Which cephalosporin covers MRSA?
Ceftaroline
What are the 4 commonly used Beta-lactam/Beta-lactamase antibiotics?
- Unasyn (Ampicillin/Sulbactam)
- Augmentin (Amoxacillin/Clavulonate)
- Zosyn (Piperacillin/Tazobactam)
- Timentin (Ticarcillin/Clavulonate)
What is the generic name for Unasyn?
Ampicillin/Sulbactam
What is the generic name for Augmentin?
Amoxacillin/clavulanate
What is the generic name for Zosyn?
Piperacillin/Tazobactam
What is the generic name for Timentin?
Ticarcillin/Clavulante
The beta-lactam/beta-lactamase meds all cover what?
- Streptococcus
- Anaerobes
- Most gram-(-) rods
- -Piperacillin and Ticarcillin also cover Pseudomonas
What does the beta-lactamase inhibitor do? Why add it to the beta-lactam?
Adds Staph coverage
Expands gram-neg rod coverage
Which Abx are safe in pregos?
- Penicillins (ALL of them)
- Cephs (ALL)
- Aztreonam
- Carbapenems
- Nitrofurantoin (eg, UTI)
- Metronidazole
- Azithromycin
Flagyl + EtOH –>??
Disulfuram-like reaction –> Nausea + Vomiting
Flagyl adverse effects?
Metal taste
CNS disturbance
Imipenem adverse effect?
Seizures
Quinolones adverse effects?
- Bone/tendon growth abnormality
- Avoid in pregnancy/children
- Rare QT prolongation
All UTIs present with?
Dysuria
What is dysuria?
“F U Bitch”
Frequency
Urgency
Burning
What is urinary frequency?
urge to urinate often, without much urine coming out
what question can you ask to assess for urinary urgency?
“When you feel you have to go, do you feel you have to RUN to the bathroom?”
Frequency vs Polyuria
Frequency = going often, may or may not pee a lot Polyuria = increased volume of urine (eg, DM, DI)
What clinical presentation do you expect in a pt with Cystitis?
look for Dysuria (FUB) + Suprapubic/bladder pain + Afebrile + UA > 5-10 WBCs
Patient presents with dysuria, suprapubic pain + U/A 6 WBCs. T* 37.3*C. Next best step in therapy?
start treatment with Abx (Nitrofurantoin, Fosfomycin, or Bactrim). Do not wait for results of urine culture.
What are the drugs to use for Cystitis?
Nitrofurantoin
Fosfomycin
Bactrim
What dose of Nitrofurantoin may you use to tx Cystitis?
Nitro 100 mg BID x 5 days
What dose of Fosfomycin may you use to tx Cystitis?
Fosfo 3 g single dose
What dose of Bactrim (TMP/SMX) may you use to tx Cystitis?
Bactrim DS 1 bid x 3 days
DS = double strength
What would you do if the cystitis is “complicated”?
extend length of Abx
Who is treated longer for cystitis, males or females?
Males b/c of longer UT and likely anatomical defect.
Male presents with UTI. Next step after empiric treatment?
Renal/Urinary tract imaging with U/S or CT.
Complicated UTIs need at least how many days of therapy?
7 days.
What is usually the case when a patient has a complicated UTI?
obstruction or foreign body 2/2
- stone
- stricture
- tumor, obstruction, neurogenic bladder
- Pregnancy
- catheters
- diabetes
what is the clinical presentation of Pyelonephritis?
Dysuria + UA w/ WBC (more than in cystitis)
- Flank or CVA tenderness and pain
- FEVER!!!
- More “sick” than cystitis
What do you need to do diagnostically in someone with dysuria + WBC on UA + CVA tenderness + fever?
Get U/S or CT to determine CAUSE of UTI.
eg, to look for stone, stricture, obstruction
If patient gets recurrent UTIs, what may be the underlying cause?
anatomic problem causing the pyelo that is not detected on US or CT.
Outpatient Tx of Pyelo?
PO Ciprofloxacin 750 mg bid for 10-14 days.
What is the clinical significance b/w PO and IV Cipro
PO Cipro at higher dose (750 mg bid) has a similar “area under the curve” as IV cipro (ie, bioavailability).
Inpt tx of pyelo?
Ceftriaxone 1 g q 24 hours
Ciprofloxacin
Ampicillin and Gentamicin
Meropenem, b-l/b-lase (severe, complicated cases)
If a pt has a resistant organism causing pyelonephritis, what can they develop?
Perinephric abscess
T/F A pt with pyelonephritis will not improve after 5-7 days of treatment.
True, especially if they have a resistant organism causing a perinephric abscess
Pt with a perinephric abscess would show what on CT?
CT of kidneys will show a collection under the capsule.
What is required in the management of a perinephric abscess?
CT-guided biopsy/aspiration. Appropriate therapy has to be tailored to what is found in the culture.
How are skin infections diagnosed?
By physical exam (appearance). There’s, generally, no specific diagnostic test.
Why are there, generally, no specific, useful diagnostic tests for skin infections?
Swab cultures are worse than useless and aspirations yield little.
How many skin infections cause bacteremia?
<5%.
What is cellulitis?
deep tissue infection in the subcutaneous tissues and dermis.
Is drainage common in cellulitis?
no
What is the MC organism that causes cellulitis?
S. aureus
What is another common cause of cellulitis?
Group A beta hemolytic Strep pyogenes (less common than S. aureus).
List the following skin infections from superficial to deep.
Erysipelas, Impetigo, Cellulitis
Superficial –> Deep
Impetigo –> Erysipelas –> Cellulitis
Bright red and warm/hot skin ‘rash’
somewhat deep
culture shows GAS
Who am I?
Erysipelas
T/F Erysipelas is easier to determine by appearance
False
Superficial skin infection
“weeping, crusting, oozing lesion that may look like honey
Impetigo
IV treatment for skin infections (eg, cellulitis)
IV Oxacillin, Nafcillin
IV Cefazolin (Ancef)
IV Vancomycin if no response after 2-3 days or anaphylaxis to Penicillin
Dose of IV oxacillin or nafcillin for skin infection (eg, Cellulitis)
1-2 grams q 4 hrs
Dose of IV Cefazolin for skin infection
1-2 grams q 8 hrs
Dose of IV Vancomycin for skin infection
1 gram q 12 hours
Is Cefazolin safe when patient has rash allergy to penicillin?
yes
Topical meds for skin infection caused by staph or strep?
Mupirocin (Bactroban)
or
Retapamulin
What is muporocin used for?
It’s a topical antibiotic used against staph/strep skin infections
What is Retapamulin used for?
It’s a topical antibiotic used against staph/strep skin infections
Oral meds against staph/strep skin infections?
PO Dicloxacillin or Cloxacillin
PO Cephalexin (Keflex)
anti-MRSA (local) abx (Bactrim, Clindamycin, Doxycycline, Linezolid)
How much of dicloxacillin or cloxacillin should be used for staph/strep skin infections?
PO, 500 mg 4x/day
How much of cephalexin (Keflex) should be used for staph/strep skin infections?
PO, 500 mg 4x/day
Endocarditis - look for what in the patient?
fever
new murmur or change in a murmur
Risks of endocarditis
injection drug use
prosthetic valves
Rare manifestations of endocarditis
embolic events (splinter hemorrhage, Roth spots in eye, Janeway/Osler’s in hands/feet).
T/F Persistent bacteremia may be a feature of endocarditis
true
patient is an IV drug user, fever, new murmur.
- MLDx?
- first best test?
Endocarditis Blood cultures (3) to rule out ec.
What is a strong clinical indicator of endocarditis?
sustained or persistent bacteremia
patient is an IV drug user, fever, new murmur.
- MLDx?
- first best test?
- first test is +, next best diagnostic step?
- endocarditis
- blood cultures (+)*
- ECHO (TTE first)
*if suspicion for ec is high, start empiric Abx tx
When would you do a TEE for endocarditis?
If TTE is negative and there is persistent bacteremia.
TEE is 95% Sn and Sp.
What would you expect to see on ECHO for endocarditis?
vegetations
murmurs
When should treatment for endocarditis be started if suspicion is high?
as soon as 3 blood cx are obtained.
Empiric antibiotic therapy for endocarditis?
Vancomycin + Gentamicin
When should antibiotics be changed for endocarditis?
once blood cx grow and the specific organism and sensitivity is known, switch abx
Pt with suspected endocarditis has positive blood culture of an organism that is sensitive to PCN. The patient had been on vanc + gent. Next best step?
Switch from Vanc –> PCN b/c of more efficacy!
