Infectious Disease Flashcards
HIV/AIDS opportunistic infections based on CD4 count
- 250-500 (x 10^6/L)
- ORAL Candidiasis
- TB
HIV/AIDS opportunistic infections based on CD4 count
- 150-200 (x 10^6/L)
- Kaposi’s sarcoma
- lymphoma
- Cryptosporidiosis
HIV/AIDS opportunistic infections based on CD4 count
- 75-125 (x 10^6/L)
- PJP
- Toxoplasmosis
- Cryptococcal meningitis
- recurrent HSV ulceration
- ESOPHAGEAL Candidiasis
HIV/AIDS opportunistic infections based on CD4 count
- < 50 (x 10^6/L)
- CMV
- MAC (Mycobacterium avium complex)
esophagitis w/ symptoms refractory to treatment to Candida, think of
CMV esophagitis
HIV/AIDS patient w/ these symptoms;
- urinary retention
- b/l leg weakness
- sacral paresthesia
think of
polyradiculomyelopathy 2/2 CMV
legs spasticity indicative of upper motor neuron disease in a patient w/ HIV and a CD4 count < 50 (x 10^6/L), think of
ventriculoencephalitis 2/2 CMV
ulcers scattered throughout bowel, especially in cecum, w/ symptoms of abdominal pain and debilitating diarrhea in a patient w/ HIV and a CD4 count < 50 (x 10^6/L), think of
CMV involvement of the GI tract
in a patient w/ HIV and a CD4 count < 50 (x 10^6/L) w/ the following;
- NAGMA
- hyponatremia
- hyperkalemia
think of
adrenal insufficiency 2/2 CMV
should patients at high risk for CMV infection, including MSM and IVDU, be tested for CMV, and why or why not?
- no
- because, they are assumed to be positive
HIV-infected patient w/ cerebral involvement w/ ring-enhancing lesions that demonstrate mass effect
Toxoplasma infection
which pathogen enters the respiratory tract and can disseminate to the nervous system leading to meningitis?
Cryptococcus neoformans
what organ is a reservoir for Cryptococcus?
prostate
which granulomatous pathogens can infect the adrenal glands and cause adrenal insufficiency?
- Mycobacterium tuberculosis
- Histoplasma capsulatum
what happens during passive lung inflation on a MV w/ a closed chest?
rising intrathoracic pressure reduces venous return to the RV, and after a delay of a few cardiac cycles, LV SV falls
in which patients w/ large variations in pulse pressure reflect limited venous return function and therefore could be used as a rationale for fluid administration in a patient w/ shock?
patients in NSR AND w/ passive breathing on MV
pulse pressure variation calculation
[(PPmax - PPmin) / (PPmax + PPmin) / 2] x 100
where PP = SBP - DBP
what percentage of PPV has a sensitivity and specificity of 88% and 89%, respectively, of predicting fluid responsiveness in patients passive on MV?
> 13%
in most trials, what percentage increase in CO is considered fluid responsive and how much fluid is required to achieve this?
- 15%
- 500 mL fluid bolus
when is PPV not a reliable predictor of fluid responsiveness?
spontaneous breather, whether on or off MV
what percentage of patients w/ septic shock will still be fluid responsive at the time of ICU admission even if “adequately” resuscitated?
about 25%
even if a patient turns out to be fluid responsive, does that mean giving more fluid will improve clinical outcome?
no
is there data to demonstrate that patients who are not fluid responsive cannot occasionally benefit from additional fluids?
no
convert 37°C to °F
98.6
convert 37.5°C to °F
99.5
convert 38°C to °F
100.4
convert 38.5°C to °F
101.3
growth of Staphylococcus lugdunensis in 2 separate BCs should prompt consideration of w/u for what?
IE
catheter-related bloodstream infection d/t Staphylococcus lugdunensis should be managed similar to recommendations for what pathogen?
Staphylococcus aureus bacteremia
how should catheter-related bloodstream infection d/t Staphylococcus aureus?
- prolonged course of abx
- catheter removal
- TEE
which coagulase-negative staphylococci characteristically causes lower UTI?
S saprophyticus
which coagulase-negative staphylococci have been a/w clinical disease and characteristically cause systemic infection?
- S epidermidis
- S haemolyticus
if there is an uncomplicated catheter-related bloodstream infection 2/2 S epidermidis or S haemolyticus what are the IDSA management guidelines?
abx for 5-7 days if the catheter is removed
HAP abx course duration
7 days
VAP abx course duration
7 days
GN bacteremia abx course duration if;
- afebrile x ≥ 48 hours
- hemodynamically stable x ≥ 48 hours
- adequate source control
7 days
abx course management in patients w/ Enterobacteriaceae bacteremia w/ adequate source control and appropriate clinical response by day 5 of parenteral abx
can switch to PO for rest of 7 day abx course
what should be done as an important antibiotic stewardship in the management of uncomplicated gram-negative bacteremia?
- reducing abx duration
- switching from IV to PO
abx course management for S aureus even if uncomplicated bacteremia and catheter removal leads to a patient quickly becoming afebrile w/ a normal WBC count
14 days
why does S aureus bacteremia abx duration need to be a minimum of 14 days?
endovascular adhesiveness (S aureus is “sticky”)
the risk of endocarditis from enterococcal bacteremia is higher in which situation?
community-acquired
how is Enterococcus similar to S aureus
endothelial adhesiveness (“sticky”)
candidemia treatment course duration W/O obvious metastatic complications
14 days after documented clearance of Candida species from bloodstream and resolution of symptoms attributable to candidemia
what condition must be excluded and therefore exam is mandatory in a patient w/ candidemia?
- endophthalmitis
- ophthalmologic evaluation
- hypersalivation
- dysphagia
- marked instability of temperature regulation
- myoclonus
rabies
this viral pathogen transmits from peripheral nerves to the spinal cord and ascends into the brain; can be conceptualized as being myeloencephalopathy
rabies virus
main source for rabies transmission worldwide
dog bites
postexposure prophylaxis for rabies is indicated for which HCPs?
healthcare professionals exposed to mucous membranes, or open skin contact w/ saliva, tears, or nervous tissue
the CDC emphasizes considering which diagnosis in any patient w/ acute unexplained encephalitis before organ transplantation?
rabies
neurotropic virus that may present as a stroke-like syndrome
West Nile virus
can West Nile virus present as altered level of consciousness?
yes, because, it can cause meningitis
what are the signs/symptoms of meningitis?
- headache
- fever
- nuchal rigidity (meningismus)
- lethargy/obtunded
how can you distinguish nuchal rigidity (meningismus) from cervical spine osteoarthritis or influenza w/ severe myalgia?
- w/ OA or myalgia from influenza, neck movement in ALL directions is affected
- meningismus d/t meningeal irritation affects mostly neck FLEXION
what are the signs/symptoms of encephalitis?
- headache
- fever
- AMS
- seizures, possibly status epilepticus
- focal neurologic deficits
- GI or respiratory prodrome
olfactory seizures (manifested as aura of foul smells; rotten eggs, burnt meat), indicate what?
- temporal lobe involvement
- suggest HSV encephalitis
rabies can be difficult to distinguish from what disease?
Guillain-Barré syndrome
Guillain-Barré syndrome typical characteristics
- demyelination of nerves
- sharp pain
- autonomic neuropathy (only 20%)
spastic complication occurring after infection w/ Clostridium tetani
tetanus
marked degrees of autonomic dysfunction, including hypersalivation, can occur as a complication from what infection?
tetanus
what liver injury pattern is this?
- indirect bili = high
- direct bili = normal
- urine urobilinogen = high
- AST/ALT = normal
- ALP = can be markedly LOW
hemolytic
what liver injury pattern is this?
- indirect bili = high
- direct bili = high
- urine urobilinogen = high
- AST/ALT = high
- ALP = normal
hepatocellular
what liver injury pattern is this?
- indirect bili = normal
- direct bili = high
- urine urobilinogen = LOW
- AST/ALT = normal to high
- ALP = disproportionately HIGH
cholestatic
- biliary stasis (cholestasis)
- infection
- cholelithiasis w/o GB thickening but dilated CBD
acute cholangitis
if cholangitis is suspected, what initial imaging should be done?
US
if cholangitis is suspected, but US does not show biliary dilation, and there’s still high clinical suspicion, what imaging should be done next?
MRCP (magnetic resonance cholangiopancreatography)
if there is evidence for cholestasis on labs, what’s the next step for definitive diagnosis and biliary decompression?
ERCP (endoscopic retrograde cholangiopancreatography)
management of severe cholangitis (manifested by organ dysfunction)
ERCP w/i 24 hours
management of moderate cholangitis (manifested by at least 2 of the following; abnormal WBC count, fever, age > 74 years, hyperbilirubinemia, hypoalbuminemia) that hasn’t responded to abx for 24 hours
immediate drainage
management of mild to moderate cholangitis responding to abx
drainage w/i 24-48 hours
what are the most common organisms isolated from cultures of bile and stones 2/2 cholangitis?
- Escherichia coli
- Klebsiella
- Enterobacter
- Enterococcus
does acute cholecystitis cause hyperbilirubinemia?
no, it shouldn’t, because biliary tract drainage is preserved
what type of isolation precaution for the following pathogens?
- CPO
- MRSA
- VRE
- lice
- scabies
contact
what type of isolation precaution for the following pathogens?
- C difficile
contact plus
what type of isolation precaution for the following pathogens?
- N meningitidis
- mumps
- pertussis
droplet
what type of isolation precaution for the following pathogens?
- influenza
- invasive group A Streptococcus
contact AND droplet
what type of isolation precaution for the following pathogens?
- TB
- measles
airborne
what type of isolation precaution for the following pathogens?
- varicella; chickenpox, and disseminated herpes zoster
contact AND airborne
what are the 2 important considerations in recent guidelines for early valve replacement in a patient w/ left-sided native valve IE?
- vegetation size; > 10 mm in diameter, especially when they’re mobile
- valve location; anterior leaflet
early valve replacement for left-sided native valve IE might be considered in patients w/ which complication if appropriate abx have been given x 48 hours?
- recurrent emboli
- HF not improving w/ medical therapy
what is persistent bacteremia?
positive BCs x 5-7 days despite abx
is it normal for S aureus bacteremia to persist > 72 hours?
yes
what is complicated S aureus and how should management be adjusted?
- persistent bacteremia > 72 hours
- abx duration should be > 14 days
what are the different ways FMT can be administered?
- swallowing pills
- upper endoscopy
- through a NG tube
- colonoscopy
- retention enema directly in the colon
what therapy can be considered to avoid emergent colectomy in severe CDI?
FMT
empiric bacterial meningitis therapy
- ceftriaxone
- ampicillin
- vancomycin
- dexamethasone
dexamethasone dose and duration for Streptococcus pneumoniae meningitis
- 0.15 mg/kg q6h
- 4 days
should dexamethasone empirically started for Streptococcus pneumoniae meningitis be stopped before 4 days duration if CSF or BCs are negative?
yes
is there a role for routine monitoring of ICP in patients w/ bacterial meningitis?
no
if intracranial hypertension in bacterial meningitis is suspected, what is the goal ICP?
< 20 mm Hg
aside from abx therapy, what other treatments may also lower ICP in patients w/ bacterial meningitis and IC hypertension?
- HOB > 30° but NOT > 60° as this is a/w decreased cerebral perfusion
- hyperventilation w/ a goal PaCO2 < 30 mm Hg
ddx for;
- recurrent fevers
- night sweats
- pulmonary abnormalities
- noncaseating granulomas on lung biopsy
- recent travel
- TB
- sarcoidosis
- lymphoma
- fungal d/o’s
- recurrent fevers, night sweats, pulmonary abnormalities, noncaseating granulomas on lung biopsy, recent travel
PLUS
- severe leukopenia
- anemia
intracellular pathogen
- Brucella
- Salmonella
- Ehrlichia
- negative acid-fast bacilli smears/cultures
- negative fungal stains/cultures
- recent exposure to unpasteurized dairy
brucellosis
treatment for brucellosis
doxycycline and an aminoglycoside (streptomycin or gentamicin)
what percentage of patients w/ brucellosis can p/w pulmonary nodules?
1-4% (uncommon)
how is Brucella transmitted?
ingestion of contaminated meat or unpasteurized dairy products
- undulating fever
- cough w/ mucopurulent sputum
- myalgias
- arthralgias
- leukopenia
- AST/ALT elevation
- abnormal chest imaging
diagnosis?
brucellosis
is there a high rate of false negative BCs when diagnosing brucellosis?
yes; need to have high clinical suspicion
what has the highest sensitivity and is the gold standard for diagnosing brucellosis?
bone marrow cultures
what is the typical finding on BM, liver, or lung tissue cultures for brucellosis?
noncaseating granulomas
what are the 3 mechanisms of resistance Pseudomonas aeruginosa possesses?
- AmpC β-lactamases
- efflux pumps
- outer membrane porin alterations
which cephalosporin is structurally similar to ceftazidime but is modified and has increased antipseudomonal activity and some activity against some ESBL strains?
ceftolozane
which β-lactamase inhibitors don’t possess a β-lactam?
- avibactam
- vaborbactam
what are the underlying conditions a/w severe pneumococcal infection and are also indications for pneumococcal vaccine?
- functional or anatomical asplenia
- HIV infection
- lymphoma (both Hodgkin’s and NHL)
- MM
- alcoholism
Austrian triad
- pneumococcal PNA
- meningitis
- endocarditis
acute illness is suggested by what clinical scenario?
histamine-mediated phenomenon
the following are classical features of what pathology in a patient w/ a h/o malignancy and/or is on chemotherapy?
- fever
- abdominal pain w/ cramping
- diarrhea
- GI bleeding
neutropenic enterocolitis
diagnostic procedure of choice for neutropenic enterocolitis
CT a/p w/ iv contrast
the following are risk factors for what?
- prolonged broad spectrum abx
- extended ICU stay (> 8 days)
- respiratory failure w/ MV
- parenteral nutrition
- AKI
- abdominal surgery
- neutropenia
- severe sepsis
fungemia
Candida species COLONIZATION from which sites increases deep-seeded Candida infection by 3-fold?
nonsterile sites such as, lung or urine
what is the gold standard for diagnosis of Candida species?
isolation from an otherwise sterile site, such as, blood or peritoneal cavity
false positives w/ galactomannan and beta-D glucan can occur, especially under what circumstances?
administration of piperacillin/tazobactam and other fungal-derived abx
guidelines recommend which antifungal for candidemia?
an echinocandin
- caspofungin
- micafungin
- anidulafungin
which empiric therapy should be considered in LOW-risk, clinically stable patients w/ candidemia?
fluconazole
which step-down therapy from an echinocandin is recommended?
fluconazole
what is the treatment of choice for endophthalmitis d/t their ocular penetration?
azoles
management of candidemia aside from antifungals
- removal of central venous catheters
- retinal exam at least once
- BCs q48h
antifungal duration for candidemia
14 days from last negative BC
facultative anaerobic GNR that can cause sepsis w/ meningitis, particularly in postsplenectomy patients, after DOG exposures
Capnocytophaga canimorsus
skin lesions a/w Capnocytophaga canimorsus which are characteristically nonblanching
purpura fulminans
treatment for Capnocytophaga canimorsus
- usually susceptible to penicillin, but some prefer
- third-generation cephalosporin, or
- β-lactamase inhibitor combination
classic skin lesion in patients w/ Pseudomonas aeruginosa
ecthyma gangrenosum
halophilic (“salt-loving”), GNR that is found worldwide in warm coastal salt waters
Vibrio vulnificus
Vibrio vulnificus can cause primary sepsis in certain high-risk populations, which include?
- chronic liver disease
- immunodeficiency
- iron storage d/o’s
- ESRD
- DM
most reports of primary sepsis in the USA from Vibrio vulnificus are a/w what?
ingestion of raw or undercooked oysters harvested from the Gulf Coast
Rocky Mountain spotted fever (RMSF) is caused by
Rickettsia rickettsii
the clinical spectrum of RMSF includes
skin lesions and CNS involvement
why do the skin lesions caused by Rickettsia rickettsii typically involve the wrists, palms of the hands, ankles, and soles of the feet?
because of enhanced proliferation in cooler body parts
what type of skin rash is classically seen w/ Rickettsia rickettsii?
petechial rash
what does MIC stand for?
minimum inhibitory concentration
are bactericidal abx more efficacious than bacteriostatic abx?
no, studies have shown they are equally efficacious; even in neutropenia, endocarditis, and meningitis
what pharmacologic property when administering abx against resistant gram-negative pathogens in the ICU has been most consistently a/w improved outcomes in patients w/ pulmonary infections, including HAP and VAP?
time above MIC
- fever
- generalized erythroderma
- profound shock
- MOF
- result of capillary leak and tissue damage induced by bacterial toxins
TSS (toxic shock syndrome)
what is positive ice pack test?
ptosis improves following application of ice to orbits for 2 minutes
what are the neurotoxin-producing, spore-forming anaerobic bacteria that may contaminate food or illicit IV drugs?
- Clostridium botulinum
- Clostridium butyricum
- Clostridium baratii
how many forms of botulinum toxin are there and how many can cause human botulism?
- 7 forms (A-G)
- 4 forms (types A, B, E, and occasionally F)
when can botulism symptoms appear after inoculation?
≥ 10 days
botulism classically causes descending FLACCID paralysis characterized by
- ptosis
- diplopia
- dysphagia
- dilated nonreactive pupils
- respiratory distress
how does food botulism classically occur?
ingesting contaminated food, classically during HOME CANNING
how does wound botulism occur?
- following trauma or surgery
- IV drug use
what empiric treatment should be started for botulism if high on the ddx?
botulinum antitoxin
what additional therapy aside from botulinum antitoxin should be done for botulism?
- wound debridement if present
- empiric abx
- organ failure support
how long does regeneration of new neuromuscular junctions and restoration of muscle strength take?
weeks to months
should a positive ice pack test be used to confirm myasthenia gravis?
no
definition of VAP (ventilator-associated PNA)
PNA in patient receiving MV that occurs 48 hours AFTER intubation
definition of HAP (hospital-acquired PNA)
PNA NOT a/w MV that occurs at least 48 hours after admission in a patient who has NOT been intubated at the time of admission to the hospital
the use of combination therapy to cover Pseudomonas aeruginosa has been demonstrated to do what?
cover multiple resistance mechanisms
what are risk factors a/w Candida auris, which is a multiresistant pathogen that can cause in-hospital epidemics?
- DM
- recent surgery
- CVC
- receiving systemic antifungal therapy
which dimorphic fungus characteristically causes infection in HIV-infected and other immunosuppressed patients, particularly those who live or have traveled to Southeast Asia?
Talaromyces marneffei (formerly Penicillium marneffei)
- dimorphic fungus
- fever
- weight loss
- nonproductive cough
- skin lesions
- hepatosplenomegaly
- lymphadenopathy
- endemic to Southeast Asia
Talaromyces marneffei (formerly Penicillium marneffei)
- mold
- usually cause bloodstream infection in severely immunocompromised patients; especially w/ neutropenia or severe T-cell immunodeficiency
- multidrug-resistant
Fusarium species
- ubiquitous, filamentous fungi present in soil, sewage, and polluted waters
- can be colonizers of previously damaged bronchopulmonary system
- can be acquired from a near-drowning even
Scedosporium apiospermum (sexual state; Pseudallescheria boydii), and Scedosporium prolificans
Scedosporium apiospermum (sexual state; Pseudallescheria boydii), and Scedosporium prolificans can cause what?
- PNA
- brain abscess
what is the most common species of malaria that makes up > 90% of all cases?
Plasmodium falciparum
- AMS
- anemia
- thrombocytopenia
- AKI
- ARDS w/ DAH
- metabolic acidosis
- shock
- endemic in tropical areas, especially sub-Saharan Africa
severe malaria
management of severe malaria
- interim oral treatment w/ artemether-lumefantrine (Coartem)
- call CDC Malaria Hotline to see if patient qualifies for artesunate iv
which medication has been shown to reduce risk of death in the treatment of severe malaria compared to quinidine?
artesunate iv
what medication can be used to treat uncomplicated malaria but would NOT be appropriate to treat severe malaria?
doxycycline iv
what age should empiric treatment for Listeria monocytogenes be given in bacterial meningitis?
adults > 50 yoa
what medication should be given to empirically treat for Listeria monocytogenes?
ampicillin
what medications should be given to cover for Streptococcus pneumoniae?
ceftriaxone or cefotaxime AND vancomycin (until c&s come back in case it’s resistant to 3rd-gen cephalosporins)
what medication should be given to reduce neurologic sequelae of bacterial meningitis 2/2 pneumococcus?
dexamethasone
- AMS
- seizure
- CSF w/ lymphocytic pleocytosis w/o hemorrhage
- MRI w/ symmetric hyperintensities in the basal ganglia and thalami
- mosquito bites while camping
- summertime
viral encephalitis, most likely from West Nile virus
- AMS
- seizure
- CSF w/ lymphocytic pleocytosis w/ hemorrhage
- hemorrhagic lesion in the temporal lobe on MRI
viral encephalitis, most likely from herpes virus
CNS involvement in the setting of immunosuppression (HIV) which leads to primary CNS lymphoma, not encephalitis
Epstein-Barr virus
- can cause severe encephalitis, but is exceedingly rare
- largely occurs in children
- typically occurs in winter months
influenza
how do meningitis and encephalitis differ?
w/ meningitis cognition should be preserved
what are the neurologic manifestations of encephalitis?
- AMS
- seizures
- focal neurologic abnormalities (hemiparesis, CN palsies, exaggerated or pathologic DTRs)
therapy for WNV, WEE, EEE, and other arboviruses
supportive
treatment for HSV-1 encephalitis
acyclovir 10 mg/kg/dose q8h
are neurologic deficits common after recovery from viral encephalitis?
yes, regardless of etiology
what neurologic deficits can occur after recovery from viral encephalitis?
- behavioral abnormalities
- amnesia
- severe cognitive impairment
- dysnomia (difficulty recalling words, names, numbers)
- impaired new learning
main therapy for lung abscess
empiric abx therapy for an extended period of time
what characteristics should empiric abx for treatment of lung abscess have?
- should penetrate lung tissue
- should provide good anaerobic coverage
what empiric abx should be used for lung abscess?
- β-lactam/lactamase inhibitor combination, OR
- carbapenems, OR
- clindamycin
duration of abx for lung abscess
- 6 weeks to 6 months
- iv for the first 1 to 2 weeks then po for the rest if good clinical response
when should surgical resection of lung abscess be considered?
- no response to abx
- size > 6 cm
why is surgical resection of lung abscess not first-line therapy?
a/w higher mortality
what procedures should NOT be attempted for management of lung abscess and WHY?
- thoracentesis, chest tube, and transthoracic biopsy
- can contaminate the pleural space and lead to empyema
what are lung abscesses often 2/2?
recurrent aspiration
which abx cannot be used to treat lung abscesses because they don’t have sufficient anaerobic coverage?
- cephalosporins
- macrolides
- fluoroquinolones
tissue plasminogen activator and deoxyribonuclease are effective in improving pleural fluid drainage and reducing the need for surgery in treating which conditions?
- complicated pleural effusion
- empyema
what pathogen is defended against by cell-mediated immunity and can cause sepsis in up to 10% so should be suspected in HIV-infected patients?
Histoplasma capsulatum
what is the classic pattern of involvement of Histoplasma capsulatum?
infection of the lungs followed by dissemination to reticuloendothelial structures (liver, spleen, BM, LNs) and to mucocutaneous sites
what are the expected physical exam findings and laboratory findings of Histoplasma capsulatum based on its classic pattern of involvement?
- transaminitis
- pancytopenia
- lymphadenopathy
- GI bleed
like TB, histoplasmosis can infect which organ leading to what?
- adrenal glands
- primary adrenal insufficiency
diagnosis of histoplasmosis
- BCs
- cultures from BM
- respiratory cultures, OR
- cultures from other involved sites
severe disseminated histoplasmosis can show what on PBS?
Histoplasma organisms ENGULFED by WBCs (yeah! get’em!)
what method is sensitive for rapid diagnosis of disseminated histoplasmosis but not for chronic forms of pulmonary histoplasmosis?
Histoplasma antigen in blood or urine
treatment of moderately severe to severe disseminated histoplasmosis?
liposomal amphotericin B for at least 2 weeks w/ possible step-down to po itraconazole
Histoplasma can result in a secondary form of hemophagocytic syndrome aka
hemophagocytic lymphohistiocytosis (HLH)
hemophagocytic syndrome aka hemophagocytic lymphohistiocytosis (HLH) is characterized as a hematologic d/o manifested by what clinical findings?
- extreme inflammation
- unregulated immune activation
what organs are classically affected 2/2 HLH?
- GI tract
- endocrine glands
- skin
- liver
HLH can be divided into primary (genetic or familial forms), and secondary forms; what are the causes of secondary HLH?
- infection
- AI disease
- malignancy
- immunodeficiency 2/2 organ transplantation
what specific form of secondary HLH occurs in a/w AI diseases, most classically systemic juvenile idiopathic arthritis?
macrophage activation syndrome (MAS)
what are the characteristic features of HLH?
- prolonged fever
- hepatosplenomegaly
- cytopenia
- very high ferritin
- high triglycerides
- transaminitis
- high bilirubin
- LOW fibrinogen
what disease marker is typically very high, but if negative does not exclude HLH?
IL-2 receptor; particularly the apha (CD25) subunit
primary HLH is a diagnosis of exclusion so what needs to be ruled out first?
secondary causes of hyperferritinemia
the following Yamaguchi criteria are used to diagnose what disease?
- major criteria
1. fever ≥ 39°C ≥ x 1 week
2. arthralgia/arthritis x ≥ 2 weeks
3. nonpruritic salmon-colored rash on trunk/extremities, and
4. granulocytic leukocytosis (≥ 10,000) - minor criteria
1. sore throat
2. lymphadenopathy
3. hepatomegaly or splenomegaly
4. transaminitis, and
5. negative tests for RF and ANA
adult-onset Still’s disease
if prolonged use of nasal tamponade devices leading to profound hypotension and skin rash, think of
toxic shock syndrome (TSS)
aside from source control but removing the offending agent, treatment for TSS must include what?
MRSA coverage w/ vancomycin
diagnosis of CDI
- clinically significant diarrhea (≥ 3 loose stools w/i 24 hours)
- relevant risk factors; recent abx use, hospitalization, advanced age
- positive stool C diff toxin by EIA or PCR
does testing for C diff distinguish between CDI and asymptomatic carriage?
no
should you test patients who are asymptomatic for C diff or are actively receiving treatment for CDI?
no
can stool assays remain positive for C diff during or after clinical recovery from CDI?
yes
treatment for initial cases of CDI
- vancomycin 125 mg po q6h, OR
- fidaxomicin
treatment for CDI in critically ill patients for whom oral therapy can’t be given
metronidazole 500 mg iv q8h w/ colonic administration of vancomycin
definitive treatment of CDI in severely critically ill patients who are > 60 yoa w/ acute abdominal distention and ileus
colectomy
treatment of recurrent CDI (> 1 episode) (no rigorous studies of management)
- vancomycin 250 to 500 mg po q6h, OR
- fidaxomicin, OR
- rifaximin, OR
- addition of an antitoxin MAB
treatment of refractory CDI for those whom surgery is extremely high risk
- FMT, OR
- toxin A/B MAB
should patients who are C diff toxin-positive but asymptomatic be treated?
no!
what should be done regarding concomitant abx when treating CDI?
- stop any abx that can be stopped
- narrow the spectrum and/or shorten abx duration if possible
nocardiosis typically presents as
- pulmonary infiltrates
- CNS infiltrates
- can be protean (able to change frequently or easily)
the order Actinomycetales has which 3 genuses (or genera) which cause human infection
- Nocardia
- Mycobacteria
- Actinomyces
Actinomyces infections typically affect
head, neck, and abdomen w/ a tendency to form abscesses and fistulous tracts
what diagnostic information is highly suggestive of Nocardia infection?
weakly acid-fast staining on BC
treatment for nocardiosis
trimethoprim-sulfamethoxazole
what are the most common adverse effects of trimethoprim-sulfamethoxazole?
- GI upset
- allergic skin reactions
treatment for Actinomyces
high-dose PCN
adverse effect of PCN
anaphylaxis
Nocardia infection can occasionally be mistaken for what infection?
TB and nontuberculous mycobacterial infection
type of infection a/w solid organ or hematologic transplant
- first month
hospital acquired infection
type of infection a/w solid organ or hematologic transplant
- 1 to 6 months
opportunistic infection
type of infection a/w solid organ or hematologic transplant
- 6 months to 1 year or more
community acquired infection
infections a/w types of immunosuppression
- antilymphocyte globulins
activation of latent viruses
infections a/w types of immunosuppression
- glucocorticoids
- bacteria
- PJP
- hepatitis B
- hepatitis C
infections a/w types of immunosuppression
- azathioprine
neutropenic infections
infections a/w types of immunosuppression
- MMF
- late-onset CMV
- bacterial
infections a/w types of immunosuppression
- cyclosporine
- tacrolimus
- viral
- intracellular pathogens
infections a/w types of immunosuppression
- plasmapheresis
encapsulated organisms
infections a/w types of immunosuppression
- MAB
- bacterial
- viral
what are the most common sites of infection in renal transplant patients?
- same as nontransplant patients
- lung
- urinary tract
- abdomen
in patients who have transplanted > 1 year ago the most common organisms causing infection are similar to nontransplanted patients, which are?
- mainly gram-negative bacteria
- Escherichia coli
- Klebsiella pneumoniae
- Pseudomonas aeruginosa
followed by gram-positive bacteria
- Staphylococcus aureus
- Streptococcus pneumoniae
- Enterococcus species
- fungi, such as Pneumocystis jirovecii, can also be important
in a retrospective observational study of renal transplant patients w/ severe sepsis or septic shock in the ICU, hospital mortality was independently a/w what factors?
- male sex
- hematologic dysfunction
- MV
- graft dysfunction
which abx is stable in the presence of all 3 classic mechanisms of gram-negative resistance to carbapenems;
- inactivation by β-lactamases
- impermeability
- efflux
cefiderocol
nosocomial PNA is broken down into 2 clinical entities, which are?
- hospital-acquired bacterial PNA (HABP)
- ventilator-associated bacterial PNA (VABP)
ventilator-associated bacterial PNA is broken down into what 2 stages?
- early
- late
hospital-acquired bacterial PNA is broken down how?
- non-ventilated;
= wards
= ICU - ventilated
= vHABP
which GNRs have a high-level resistance to β-lactams, cephalosporins, and carbapenems?
- Pseudomonas spp
- Stenotrophomonas maltophilia
- ESBL Klebsiella pneumoniae (including carbapenem-producing strains)
GNR that is lactose fermenting, and carbopenamase-producing
Klebsiella pneumoniae
what are the lactose-fermenting GNRs that can develop resistance to abx through extended spectrum beta-lactamases (ESBLs)?
- Klebsiella pneumoniae
- Enterobacter cloacae
- Escherichia coli
ESBLs are enzymes that allow bacteria to be resistant to which abx?
- beta-lactam abx
= penicillins
= cephalosporins
= aztreonam (monobactam)
what bacterial strain, present in North America and the Middle East, has carbopenemase conferring resistance to all beta-lactam abx?
KPC strain (Klebsiella pneumoniae carbopenemase)
what bacterial strain contain zinc for activity and is therefore dubbed a metall-beta-lactamase, and is commonly found in southeast Asia?
NDM-1 strain (New Delhi metallo-beta lactamase)
what therapy is now being used to combat resistant strains such as KPC and NDM-1?
combination of antipseudomonal abx w/ a carbopenemase inhibitor, usually avibactam or vaborbactam
what are the 2 most frequently used abx w/ activity against KPC?
- ceftazadine-avibactam
- meropenem-vaborbactam
what other abx can be used for KPC, but limited d/t their side effect profile (AKI)?
- colistin
- tigecycline
treatment choice for Stenotrophomonas maltophilia
trimethoprim-sulfamethoxazole
when administering beta-lactam abx to critically ill patients w/ bacteremia, what best correlates w/ successful microbiologic eradication?
prolonged infusion (time-dependent effect)
bacteremia from what organism is a common problem in OLT patients?
Pseudomonas aeruginosa
what should be on the ddx for recurrent Pseudomonas aeruginosa bacteremia despite adequate abx in an OLT patient that’s admitted for small bowel perforation 2/2 duodenal ulcer?
occult intraabdominal abscess
bacteremic seeding of the kidneys w/ development of small renal abscesses occurs as a complication of which 2 organisms?
- Staphylococcus aureus bacteremia
- Candida species fungemia
how does Mycobacterium tuberculosis contribute to HIV-1 replication?
activation of the transcription factor, nuclear factor-kappa B
can active disease caused by Mycobacterium tuberculosis directly increase the level of HIV-1 infection?
yes
should ART be withheld until completion of TB treatment given drug-drug interactions?
no! since active Mycobacterium tuberculosis directly increase the level of HIV-1 infection
which pathogen is angioinvasive and in neutropenic patients occlude blood vessels thereby mimicking the physiology of a PE?
Aspergillus infection
Streptococcus pneumoniae, in asplenic patients, particularly those who required splenectomy 2/2 a hemoglobinopathy, what 2 clinical problems may occur and result in elevated right-sided pressures?
- increased rate of thrombosis, including PE
- recurrent inflammation and thrombosis leading to pHTN
what are the 3 main ways a pathogen can cause disease?
- direct destruction or inflammatory effect
- toxin production
- immunologic effect
what metric is used to guide preemptive treatment in hematopoietic-cell transplant patients that are CMV positive to prevent a direct effect of the virus?
CMV viral load
in HCT patients, indirect effects of CMV include increased incidence of graft rejection and graft-vs-host disease; even if patients have low seropositivity or undetectable viral loads, patients should be considered for what?
CMV ppx w/ letermovir
what are the most characteristic pathogens to cause meningitis after trauma, neurosurgical procedures, or intracranial device placement?
- MRSA
- Pseudomonas aeruginosa
patients that are s/p trauma, neurosurgical procedures, or intracranial device placement that p/w minimal if any elevation in CSF WBCs, and normal or minimally depressed CSF glucose, think of
healthcare-associated ventriculitis or meningitis
ventriculitis or meningitis 2/2 what organism can take at least 10 days to grow?
Propionibacterium acnes
what are the 4 mechanisms that CSF shunts may become infected?
- colonization of the shunt at the time of surgery
- retrograde infection from the distal end of the shunt
- pathogen entry through the skin while entering the shunt
- hematogenous seeding
acute, febrile, and focal encephalitis
HSV encephalitis
type of meningitis that is an underreported clinical phenomenon, thought to be a T-cell-mediated delayed hypersensitivity reaction
drug-induced meningitis (aka, drug-induced aseptic meningitis; DIAM)
what drug classes have been reported to cause drug-induced meningitis?
- NSAIDs (MCC)
- abx, most notably, sufla and fluoroquinolones
- immunosuppressive-immunomodulatory drugs
- AEDs
- SLE drugs
severe demyelinating disease of the CNS caused by activation of previous John Cunningham polyomavirus (JCV) infection earlier in life
progressive multifocal leukoencephalopathy (PML)
in PML, JCV leads to demyelination that affects primarily white matter and leads to subacute deficits that include what?
- AMS
- ataxia
- visual disturbances (hemianopia and diplopia)
about 40% of patients w/ PML can develop
seizures
- affects ALL white matter tracts, including those closest to the cortex
- tracts closest to the cortex are often spared in other demyelinating d/o’s
progressive multifocal leukoencephalopathy (PML)
diagnosis of progressive multifocal leukoencephalopathy (PML) is suggested by what?
- h/o immunosuppression
- progressive neurologic symptoms
- MRI lesions localized to subcortical white matter w/ T2-weighted (T2W) images demonstrating fluid-attenuated inversion recovery
diagnosis of progressive multifocal leukoencephalopathy (PML) is confirmed by
LP w/ CSF positive by PCR for JCV
what immunocompromised conditions are a/w JCV infection?
- malignancy (lymphoproliferative/myeloproliferative d/o’s)
- HIV
- immunosuppressive therapy for organ transplant or AI d/o’s (sarcoidosis, SLE)
treatment for PML
supportive, and reconstitution of the immune system asap
most common immune-mediated, inflammatory, demyelinating disease of the CNS
multiple sclerosis (MS)
multiple sclerosis onset
acute manifestation (days to weeks) w/ periods of remission
progressive multifocal leukoencephalopathy (PML) onset
progressive over weeks to months WITHOUT periods of remission
MS is often a/w what condition that is not characteristic of PML?
focal eye findings;
- optic neuritis
- internuclear ophthalmoplegia
what MRI findings are seen w/ acute MS exacerbation?
lesions (plaques) w/ peripheral enhancement on axial contrast-enhanced T1-weighted images
patients w/ poorly controlled HIV are at risk for HIV encephalopathy which manifests as the classic triad of which symptoms?
- subcortical dementia (memory and psychomotor speed impairment)
- depressive symptoms
- movement d/o’s
- can manifest w/ oculomotor symptoms
- symptoms are typically acute
acute cerebellar strokes
what are the MRI findings in acute stroke?
- hyperintense areas on diffusion-weighted images because of cytotoxic edema w/ restricted diffusion
- then hyperintense on fluid-attenuated inversion recovery and T2W images
how can you tell if an MRI is T1?
if gray matter is DARKER than white matter (like it’s supposed to be)
how can you tell if an MRI is T2?
if gray matter is LIGHTER than white matter
- vesicles or bullae w/ underlying purpura
- septic shock
- lactic acidosis
necrotizing infection
treatment for necrotizing skin/soft-tissue infection
- vancomycin
- piperacillin/tazobactam
- clindamycin (theoretical reduction of toxin production)
- +/- IVIG (small RCTs suggest benefit)
- urgent surgical consultation
what is the utility of imaging studies in the diagnosis of necrotizing infection?
insensitive
what abx is critical in the treatment of leptospirosis and rickettsial diseases?
doxycycline
can leptospirosis or rickettsial diseases cause necrotizing skin or soft-tissue infection?
no
routine testing for the presence of ESBLs is NOT performed by most clinical microbiology labs, so instead, nonsusceptibility to what abx is used as a PROXY for ESBL production?
ceftriaxone (MIC > 2 μg/ml)
if susceptible, the use of which abx will effectively treat ESBL Klebsiella while also minimizing the risk of developing resistance to meropenem for possible future infections w/ Pseudomonas or Acinetobacter?
ertapenem
what classic tenet in ID should always be remembered regarding abx activity against Pseudomonas aeruginosa?
when treating another pathogen there’s a risk for selecting resistant strains of Pseudomonas aeruginosa so abx that don’t have activity against Pseudomonas aeruginosa should be chosen
which abx should be avoided for the treatment of infections caused by ESBL-producing Enterobacterales even if susceptible?
cefepime
what are 2 examples of ESBL-producing Enterobacterales bacteria?
- Escherichia coli
- Klebsiella pneuomoniae
which abx is a/w a significantly higher mortality rate than those treated w/ meropenem for the treatment of ESBL-producing bacterial bloodstream infections?
piperacillin/tazobactam
what test bolus can be given to determine if a patient is fluid responsive and by what percentage does the stroke volume need to increase?
- 4 ml/kg bolus
- ≥ 10%
how much whole blood enters the central circulation w/ a passive leg raise maneurver?
250-350 ml
lactose-fermenting GNR that is unusually “sticky”
hypervirulent (hypermucoviscous) Klebsiella pneumoniae (hvKp)
- subgroup of viridans streptococci that is normal human flora (found in the mouth, throat, stool, and vagina) but can lead to pyogenic abscess formation
- can lead to liver abscesses, but typically responds to drainage and abx
Streptococcus milleri group
- Streptococcus anginosus
- Streptococcus intermedius
- Streptococcus constellatus
- protozoan that usually does not produce symptoms but can lead to dysentery
- can lead to invasive infections in the lungs, heart, brain, and liver
- liver abscess is the most common extraintestinal site
- most commonly seen in India, Africa, Mexico, and Central and South America
Entamoeba histolytica
GNR that causes liver abscesses, but is NOT a/w metastasis and responds to drainage and abx
Escherichia coli
CN 1
olfactory nerve
CN 2
optic nerve
CN 3
oculomotor nerve
CN 4
trochlear nerve
CN 5
trigeminal nerve
CN 6
abducens nerve
CN 7
facial nerve
CN 8
vestibulocochlear nerve
CN 9
glossopharyngeal nerve
CN 10
vagus nerve
CN 11
spinal accessory
CN 12
hypoglossal nerve
- vomiting followed by
- oculobulbar findings
- flaccid DESCENDING paralysis
botulism
what are the CN 3 (ocular nerve) and CN 6 (abducens nerve) signs/symptoms that occur from botulism?
- accommodative paresis
- ptosis
- ophthalmoparesis
- mydriasis
what other CNs besides 3 and 6 can be involved 2/2 botulism?
CNs 9, 10, 11, and 12
how does involvement of CNs 9, 10, 11, and 12 present in botulism?
- dysarthria (poor articulation)
- dysphagia
- dysphonia (hoarse voice)
are the neuro-ophthalmic signs in botulism unilateral or bilateral?
usually bilateral
in botulism how does descending paralysis progress after the development oculobulbar findings?
quickly
if botulism is suspected who does the CDC recommend to contact?
local or state health department’s emergency on-call staff to arrange emergency expert clinical consultation because laboratory confirmation can only be performed by certain municipal and state public health laboratories
CO poisoning usually presents w/ what symptoms?
- headache
- encephalopathy
- ASCENDING paralysis
- 2/2 nerve demyelination
- AREFLEXIA
- 2/2 immunologic sequela of a diarrheal illness, most commonly Campylobacter jejuni
Guillain-Barré syndrome
Guillain-Barré syndrome tends to follow GI illness by what timeframe?
weeks
- neuromuscular junction d/o
- may occur as a paraneoplastic phenomenon or a primary AI d/o
Lambert-Eaton myasthenic syndrome
> 50% of cases of Lambert-Eaton myasthenic syndrome are a/w what?
small cell lung cancer
- proximal muscle weakness
- DTRs are usually absent
- there is often autonomic dysfunction
Lambert-Eaton myasthenic syndrome
- reticulonodular pattern
- recent travel to Southwestern USA
- severe PNA
coccidioidomycosis
in patients w/ severe disease and immune compromise, what is the recommended approach to dialysis Coccidioides?
to use multiple modalities, including;
- serologic testing for Abs
- direct visualization
- culture of sputum or BAL
in addition to serologic testing for Abs, direct visualization, and culture of sputum or BAL, what is another potential way to test for Coccidioides in patients who are immunocompromised?
serum and urine Ag testing; but again, this shouldn’t be the only diagnostic test done
what test is typically used to diagnose invasive candidiasis in critically ill patients, but is a nonspecific cell wall component of most fungal pathogens?
serum (1-3)-β-D-glucan measurement
when is LP recommended in a patient w/ suspected meningitis 2/2 Coccidioides?
- headache
- AMS
- focal neurologic deficits
- mold infection
- in immunocompetent hosts, manifests as superficial infections such as keratitis or onychomycosis
Fusarium species
- mold infection
- in severely immunocompromised hosts, manifests as sinusitis, endophthalmitis, PNA, skin infection, and fungemia
Fusarium species
- disseminated skin lesions are characteristically reddish gray macules, some w/ central ulceration but others w/ black eschar formation
- pathogen has angioinvasive properties
Fusarium species
treatment for Fusarium species
amphotericin B
what mold infection can breakthrough in a patient on azole ppx?
- much less likely for Candida or Aspergillus to breakthrough
Fusarium species
what group of antifungals lack clinically significant activity against the Fusarium species?
echinocandins (micafungin, caspofungin, and anidulafungin)
what mold infection clinically mimics Aspergillus?
Fusarium species
- pathogen has angioinvasive properties
- clinical manifestations often include evidence of infarction at the classic site of infection;
- lungs
- sinuses
- skin
- CNS
Aspergillus
mold infection that can grow in blood cultures (up to 40% of patients) and is highly characteristic of its clinical presentation
Fusarium species
pathogenic mold infection that does NOT commonly grow in blood cultures
Aspergillus
skin lesions 2/2 to mold infection that present in patients w/ neutropenia, usually occur as a single lesion, often at a site of inoculation (such as a previous IV catheter)
Aspergillus
mold that act as either primary or opportunistic pathogens to cause infections in both immunocompetent AND immunocompromised hosts
Scedosporium species
what are the spectrum of infection that Scedosporium species causes?
- asymptomatic colonization of respiratory tract
- superficial infections
- allergic reactions
- severe invasive localized or disseminated fungal infections
what is an important predisposition to infection by Scedosporium?
prior antifungal ppx NOT active against it
how can immunocompetent hosts develop clinical disease 2/2 Scedosporium?
near-drowning events in water polluted w/ fungal organisms
infection 2/2 Scedosporium typically involves which organ systems?
- sinuses
- lungs
- CNS
does Scedosporium grown in blood cultures?
rarely
does Scedosporium typically cause skin lesions?
no
which molds are in the Mucorales family?
- Rhizopus species
- Mucor species
mold infection that is second most common in patients w/ hematological malignancy or after transplant w/ mortality rates > 90% when infection is disseminated
mucormycosis
because of this mold’s propensity to use iron as an element for growth, repeat blood transfusions in patients w/ MDS who have undergone BMT are at risk of high fatality rates from this mold
Murcorales family (Rhizopus species and Mucor species)
- siderophilic (iron-loving)
- angioinvasive, inducing blood vessel thrombosis and tissue necrosis
- BCs are rarely positive w/ this pathogen
- disseminated skin lesions are NOT part of the clinical picture
Murcorales family (Rhizopus species and Mucor species)
compared to CVCs (central venous catheters), PICCs (peripherally inserted central catheters) have what risk of CLABSI and DVT?
- fourfold greater risk of BSI (bloodstream infection)
- 2.5x higher risk of DVT
HCPs who are NOT vaccinated or do NOT have other evidence of immunity to varicella are considered susceptible to varicella-zoster virus infection and are potentially infectious during what time period?
days 8 to 21 after exposure
if an HCP who is NOT vaccinated or does NOT have other evidence of immunity to varicella is exposed to a patient w/ acute varicella infection what is the most appropriate next step?
temporarily reassign to a location remote from patient-care areas from day 8 to 21 after the last exposure
if an HCP is exposed to a patient w/ acute varicella infection what is the treatment?
varicella vaccination
if an HCP is exposed to a patient w/ acute varicella infection, what is the treatment if there is a contraindication to give the varicella vaccine?
varicella-zoster immune globulin
varicella vaccination is contraindicated in which persons?
- pregnant HCP
- leukemia/lymphoma patients
- patients on immunosuppressive medications
- cellular immune deficiencies
when should varicella vaccine be given if someone is exposed to a patient w/ acute varicella infection?
w/i 3 to 5 days, but even after 5 days in case of repeat exposure
- incubation period usually 1 to 2 weeks, but can be as long as 4 weeks
- nonspecific prodrome followed by rapid development of ARDS and hemodynamic compromise
- ARDS is often hemorrhagic
hantavirus cardiopulmonary syndrome
human acquisition of hantavirus is through contact w/ what?
rodents
what phase of disease 2/2 hantavirus is characterized by significant capillary leak, resulting in noncardiogenic pulmonary edema and hypotension?
cardiopulmonary phase
progression to shock, respiratory failure, coagulopathy, and even death is often quite rapid in which viral illness?
hantavirus cardiopulmonary syndrome
hantavirus pulmonary syndrome is characterized by what?
- hemoconcentration
- thrombocytopenia
- transaminitis
- elevated LDH
- lactic acidosis
- leukocytosis, sometimes up to 90,000/µL, and circulating immunoblasts
hantavirus
this diagnostic triad is in reference to which viral illness?
- thrombocytopenia
- left-shifted, predominantly granulocytic leukocytosis
- > 10% immunoblasts
hantavirus
this viral illness is diagnosed by serology w/ results taking a month or more after the patient is d/c’d from the hospital
hantavirus
when a patient diagnosed w/ PNA fails to respond to empirical abx treatment, what things should be considered?
- obstructing airway lesion
- immunocompromise
- unusual pathogen
- incorrect diagnosis
histopathological findings
- thick-walled
- round to oval fungal yeast forms
- ~ 8 to 15 µm
disseminated blastomycosis
histopathological findings
- spherules, containing multiple endospores
- ~ 10 to 100 µm
coccidioidomycosis
histopathological findings
- narrow-based budding
- ~ 5 to 10 µm
cryptococcosis
histopathological findings
- yeasts
- often w/ pseudohyphae
- ~ 3 to 5 µm
candidemia
histopathological findings
- yeasts w/ narrow-based budding
- ~ 2 to 4 µm
histoplasmosis
treatment for life-threatening blastomycosis, including ARDS
liposomal amphotericin B until clinical improvement, then itraconazole for 6 to 12 months
what additional treatment, besides liposomal amphotericin B, for severe pulmonary blastomycosis, such as ARDS, should be considered?
corticosteroids (prednisone 40-60 mg/day or equivalent x 1-2 weeks)
treatment of invasive aspergillosis
IV voriconazole
histopathological findings
- thin, septate, acute-angle branching hyphae
Aspergillus species
AC is not considered for what time periods if a patient has an ischemic stroke vs hemorrhagic?
- ischemic = 48 hours
- hemorrhagic = up to 7 days after
what is the recommend for starting AC for embolic stroke in the setting of endocarditis?
considered risky and is typically NOT recommended
in a patient w/ a bleeding risk 2/2 cerebral abscess from septic embolization and mycotic aneurysm in other parts of the cerebral vasculature what imaging study should be done before starting AC?
digital subtraction cerebral angiography
a patient in septic shock, what physical exam finding is equivalent to lactate clearance as an end point guiding fluid and vasoactive drug treatment?
measuring peripheral circulation adequacy
what abx should be added to an empiric regimen for spontaneous gas gangrene to inhibit toxin production?
clindamycin
Clostridial myonecrosis can be caused by what 2 processes?
- trauma
- spontaneous seeding of muscle through hematogenous spread
what type of malignancy is a well-recognized risk factor for spontaneous Clostridial myonecrosis w/ the malignancy being the source of hematogenous spread of Clostridium from the GI tract to the muscle?
colorectal malignancy
- wound exposed to salt water or shellfish (opening oysters)
- eating raw shellfish (mainly seen in underlying liver disease)
- case reports from eating raw shellfish in patients w/ DM or CKD
Vibrio vulnificus
Enterobacterales was previously known as?
Enterobacteriaceae
what are the three categories pharmacokinetic/pharmacodynamic considerations when choosing abx in the ICU?
- time-dependent killing
- concentration-dependent killing
- concentration-dependent w/ time-dependent killing
- β-lactam abx
- hydrophilic
- time-dependent killing
piperacillin
- hydrophilic
- both time- and concentration-dependent killing
vancomycin
- lipophilic
- concentration dependent w/ time dependence
- is able to pass through alveolar epithelial cells to reach the epithelial lining fluid w/ concentrations approximated to be 100% of corresponding plasma values
linezolid
- hydrophilic
- concentration-dependent killing
- plasma concentrations needed to achieve an antibacterial effect often overlap w/ clinical levels that result in nephrotoxicity
colistin
oral antiviral for influenza
oseltamivir
- inhaled antiviral that is approved for ppx among close contacts of patients w/ influenza and for treatment of patients who are not at high risk
- not recommended for patients w/ uncontrolled asthma or COPD
zanamivir
IV antiviral that should be reserved for patients who cannot receive enteral oseltamivir
peramivir
- novel oral antiviral that inhibits viral cap-dependent endonuclease
- has demonstrated activity against both influenza A and B viruses
baloxavir
- inhibit viral matrix protein 2 in influenza A viruses
- have NO activity against influenza B viruses
- because of side effects and high levels of resistance, are no longer recommended for use as anti-influenza drugs in the US
amantadine and rimantadine
- exposure to this fungus is normally of little consequence
- some individuals can develop hypersensitivity leading to severe asthma, bronchiectasis, and fleeting lung infiltrates
allergic bronchopulmonary aspergillosis
exposure to this fungus in patients w/ structural lung disease such as emphysema or cystic sarcoidosis may develop this
fungus balls (aspergillomas) in lung cavities
invasive aspergillosis occurs in which patients?
immunocompromised;
- neutropenic undergoing BMT
- solid organ transplant recipients
- patients undergoing CAR-T cell therapy
- maybe advanced cirrhosis
ideal method of diagnosing invasive aspergillosis
tissue biopsy
if tissue biopsy is not possible, what other methods can be used to diagnose invasive aspergillosis?
- galactomannan or β-D-glucan (fungal Ag)
- BAL
- PCR
treatment of choice for invasive aspergillosis
posaconazole (less adverse effects) or voriconazole
what causes type A lactic acidosis?
marked tissue hypoperfusion 2/2
- hypovolemia
- cardiac failure
- sepsis
- cardiopulmonary arrest
what causes type B lactic acidosis?
toxin-induced impairment of cellular metabolism and regional areas of ischemia
- metformin
- malignancy
- alcoholism
- toxic alcohols (methanol and ethylene glycol)
- HIV infection = from sepsis and/or ART
- beta-adrenergic agonists = epinephrine
- severe bronchospasm treated w/ high-dose, inhaled beta agonists
- mitochondrial dysfunction 2/2 inherited d/o’s
- mitochondrial dysfunction 2/2 thiamine deficiency
- drug-induced mitochondrial dysfunction 2/2 propofol
- drug-induced mitochondrial dysfunction 2/2 linezolid
