February/March 2021 Flashcards
When do antibodies develop for Cocci infection?
During symptoms, which normally occur between 7 to 21 days after having been exposed
What does the presence of IgM and/or IgG Ab to Cocci signify in regards to timeline of infection? (e.g. past, previous, etc)?
- IgM and/or IgG signify recent or active. IgG does NOT last forever. It will appear close to the time IgM appears, hence they both can signify recent infection. IgG can last for several months though
- KEY: Very different from many other infections in which IgG tends to be lifelong. Easy to think that IgM/IgG have NO meaning in Cocci. They both mean the same thing – recent/active infection
Suspicion for Cocci PNA is high, but EIA Ab test is negative for IgM and IgG. What is the next step?
- Repeat EIA in 2-3 weeks; 1st week of disease 50% positive, 3rd week of disease 90% positive
What is the preferred initial screening tetss for Cocci?
- Serology (IgM/IgG) via EIA
- Negative test does NOT need confirmation
- Positive test needs confirmation
If patient has disseminated Cocci, how does that change the value of the serologies?
- Patients who have already developed extrapulmonary coccidioidal lesions nearly always exhibit anticoccidioidal antibodies in their serum, regardless of whether tested by EIA for IgG or by IDCF (aka IgG testing via immunodiffusion), and higher CF ab titers
- Lesson: Serology testing in Cocci seems to be very much connected to disease course, that is, the timing and extent. They reflect organism activity
Which serology test for Coccidioides is commonly used to measure disease activity?
- Complement fixation provides antibody titers
What is the triad that is indicative of cardiac tamponade?
- The three principal features of tamponade (Beck’s triad) are hypotension, soft or absent heart sounds, and jugular venous distention with a prominent x (early systolic) descent but an absent y (early diastolic) descent
How much pericardial fluid is there normally?
- From 10ml ot 50 ml
Does the amount of pericardial fluid determine the risk for tamponade?
- Not really. As little as 200ml can cause tamponade if accumulates quickly. If slowly, the pericardial space can hold up to 2 L WITHOUT tamponade.
Explain pulsus paradoxus and what disease dose it indicate?
- During inspiration, the negative intra-thoracic pressure results in an increased right venous return, filling the right atrium more than during an exhalation. The increased blood volume dilates the right atrium, reducing the compliance of the left atrium due to their shared septum. Lower left atrial compliance reduces the left atrium venous return and as a consequence causes a reduction in left ventricular preload. This results in a reduction in left ventricular stroke volume, and will be noted as a reduction in systolic blood pressure in inspiration. Pulsus paradoxus is therefore an exaggeration or an increase in the fall of systolic BP beyond 10 mmHg during inspiration.
TIP: there is nothing “pulsus” nor “pardoxical” about pulsus paradoxus. It is more like “pressure” “exaggeratus”
What are the most common malignancies - primary and secondary - associated with malignant pericardial effusions?
Most common primary malignancy to cause: Mesothelioma
- TIP: INCURABLE
Secondary Malignancies:
- Lung
- Breast
- Lymphoma/Leukemia
- Melanoma
How to conceptualize the cause of pathologic gynecomastia in males?
Testosterone/Estrogen ratio is DESCREASED
o Decrease of T:
Primary testicular failure
o Increase of E:
- HCG/LH stimulate testicles to make E e.g. Lung/germ cell tumors can make HCG (HCG is similar to LH)
- Androstenedione peripheral conversion (aromatization) e.g. Adrenal tumor
- Decreased clearance due to liver disease
What age is osteoporosis screening recommended for women?
> 65 yo (after menopause is key as estrogen deficient states increase risk for osteoporosis)
What is the strongest risk factor for RCC?
Smoking
What histologic cell type for RCC is the most common?
Clear cell carcinoma makes up 60% of the cases
What is the most common way RCC is diagnosed?
Incidental imaging for other reasons
What is RCC’s known response to chemotherapy
Characteristically known to be resistant to chemotherapy amongst the cancers
Between non-treponemal and treponemal serologic tests, which remains life long in patient’s having had syphilis, regardless of treatment status and stage of dissease?
Treponemal tests last forever REGARDLESS of the test e.g. TPPA, FTA-ABS, etc
What serologic test for syphilis is used for treatment response?
Non treponemal tests i.e. RPR
What are nontreponemal tests measuring?
- Cardiolipin, lecithin and cholesterol
- Interesting: the thought is that syphilis, causing damage to cells, causes the release of phospholipids
What are the available treponemal tests?
What is the most sensitive treponemal test to confirm early infection ?
FTA ABS
What are the available treponemal tests?
TPPA – treponemal pallidum particle agglutination
FTA – ABS – Fluorescent Treponemal Antibody-Absorption Assay
What is the difference between the following terms referring to fungi:
- Yeast
- Mold
- Hyphae
- Pseudohyphae
- Mycelium
- Yeast: single cell fungi
- Mold: multicellular fungi
- Hyphae: filamentous form of fungi (AKA hyphae = filament) – can be septated or nonseptate
- Pseudohyphae: Chains of fungal cells. “Pseudo” because they look hyphae, but in reality, each new cell buds from another and they are marked by constrictions as opposed to septa at each junction
Mycelium: the tangled network of hyphae
TIPS can lead to higher incidence of PSE. Does the use of Rifaximin prevent PSE (primary ppx) in patients with TIPS (for ascites; no history of PSE)?
Annals of Internal Medicine 2020
RCT, double blind, multicenter
Yes!
RESULTS: An episode of overt HE occurred in 34% (95% CI, 25% to 44%) of patients in the rifaximin group (n = 93) and 53% (CI, 43% to 63%) in the placebo group (n = 93) during the postprocedure period (odds ratio, 0.48 [CI, 0.27 to 0.87]). Neither the incidence of adverse events nor transplant-free survival was significantly different between the 2 groups.
CONCLUSION: In patients with cirrhosis treated with TIPS, rifaximin was well tolerated and reduced the risk for overt HE. Rifaximin should therefore be considered for prophylaxis of post-TIPS HE.
Bureau C, Thabut D, Jezequel C, et al.The Use of Rifaximin in the Prevention of Overt Hepatic Encephalopathy After Transjugular Intrahepatic Portosystemic Shunt : A Randomized Controlled Trial.Ann Intern Med. 2021 Feb 2. doi: 10.7326/M20-0202.
What antihypertensive, given after AMI in patients with heart failure, lead to longer life expectancy?
Ramipril
CONCLUSION: For patients with clinically defined heart failure following AMI, ramipril results in a sustained survival benefit, and is associated with an extension of life of up to 14.5 months for, on average, 13 months treatment duration.
Wu J, Hall AS, Gale CPLong-term survival benefit of ramipril in patients with acute myocardial infarction complicated by heart failure.Heart. 2021 Jan 15. pii: heartjnl-2020-316823. doi: 10.1136/heartjnl-2020-316823.
What serologic test is best used to indicate that a patient has had a syphilis infection any time in their life?
Treponemal antibodies appear earlier than nontreponemal antibodies and usually remain detectable for life, even after successful treatment
What are the steps of the reverse algorithm for syphilis screening/testing?
In the reverse algorithm for syphilis testing, what are the possible explanations for a discordant test result?
I.e. Treponemal Ab POS/Non treponenal Ab NEG
Discordant testing results could be caused by
1) previous syphilis infection, treated or untreated, with persistence of treponemal antibodies but seroreversion of nontreponemal antibodies
2) a false-positive treponemal test result
or
3) early primary syphilis in a person who has yet to develop nontreponemal antibodies.
Framework Question:
What is the pathogenesis of ascites from portal hypertension (for example, cirrhosis)?
Simply, portal hypertension and the resultant renal salt and water retention that is a result but also a exacerbating factor, are the causes of ascites. Portal hypertension is hydrostatic pressure. Since albumin can’t cross the vasculature, fluid shifts from portal system to peritoneal space, hence the albumin in the peritoneal space becomes less concentrated compared to the serum.
Portal hypertension, plainly, increased pressure in the portal system is a product of resistance. Ohm’s law describes pressure = resistance x flow (P=FR, “puffer”).
It is the increased resistance that leads to portal hypertension. 3 causes:
1) Hepatic fibrosis which defines cirrhosis
2) Hepatic stellate cells activativation lead to vasoconstriction of the smooth muscle cells as well as their fibrosis
3) Decreased eNOS causes increased hepatic vasocontriction
Renal salt and water retention is caused by systemic vasodilation and ineffective circulating blood volume:
- Cirrhosis leads to systemic NO
- Vasodilation especially in the splanchnic circulation
- Pooling of blood in the splanchnic circulation
- Body interprets as a state of hypovolemia
- RAAS and ADH system respond by renal salt and water retention, worsening the ascites
Explain how SAAG >1.1 is indicative of portal hypertensive causes of ascites
Simply, portal hypertension and the resultant renal salt and water retention are the causes of ascites. Portal hypertension is hydrostatic pressure. Since albumin can’t cross the vasculature, fluid shifts from portal system to peritoneal space, hence the albumin in the peritoneal space becomes less concentrated compared to the serum.
Serum Albumin - Serum Ascites > 1.1
What is the mechanism of action of ascites in non portal hypertensive cases?
Causes include malignancy, infections and pancreatic diseases.
In the case of malignancy, the tumor cells produce protein rich fluid, which draws fluid from extracellular spaces into the peritoneum (oncotic pressure)
What are general causes of non portal hypertensive ascites?
Cardiac ascites
Malignancy (secondary and primary)
Infections (tuberculosis, chlamydia)
Intraabdominal pathologies (pancreatic disease, renal disease, biliary disease)
Paracentesis of a patient with ascites is performed. TG > 1000. What are the possible causes of chylous ascites?
Biliary trauma or disruption from any cause
- Cirrhosis
- Tumor
- Tuberculosis
- Congenital abnormalities
Clinical Tip: MRCP to eval for biliary structure
Paracentesis of a patient with ascites is performed. The fluid is BLACK. What are the possible causes?
Melanoma
Pancreatic necrosis
What does the SAAG represent physiologically?
Think of it as amount of portal HTN. It is reflective of the pressure within the hepatic sinusoids.
The greater the difference between serum albumin and ascitic albumin, the greater the portal hypertension.
SAAG >1.1
Can the interpretation of SAAG be affected by diuresis?
NO
What is the differential diagnosis of SAAG > 1.1
KEY: SAAG is representative of portal hypertension in the hepatic sinusoids. NOT just cirrhosis
Once SAAG> 1.1, the differential diagnosis is predominantly focused on causes of portal HTN
Diff Diag:
- Cirrhosis
- Hepatic venous thrombosis (Budd Chiari)
- Liver with massive mets
- Sinusoidal obstructive syndrome
- Cardiac ascites
What does ascitic protein represent physiologically? How does it aid in further refining the differential diagnosis?
Represent the integrity of the hepatic sinusoids. If ascitic protein > 2.5, this means that the hepatic sinusoids are normal AND hence, allow for the passage of protein into the ascites.
If protein > 2.5:
- Cardiac ascites
- SOS
- IVC obstruction
- Early Budd Chiari Syndrome
If protein < 2.5:
- Cirrhosis
- Late Budd chiari
- Massive liver metastasis
What ascitic fluid findings are consistent with perforated viscus?
Low Glucose
Elevated LDH
What ascitic fluid findings are consistent with pancreatic ascites?
Elevated amylase
What ascitic fluid findings are consistent with tuberculous peritonitis?
ADA (highest sensitivity)
AFB Smear
AFB culture
What is the most common cause of pediatric periodic fever syndrome
PFAPA the most commonpediatric periodic fever syndrome in the general population
What age group does PFAPA tend to occur in ?
The first symptoms of PFAPA syndrome most often begin between the ages of 11 months and 5 years
In large cohorts, only10% to 20% of PFAPA patientsexperience their first symptoms after 5 years of age.
Are all the sx of PFAPA present during fever flares?
It should be noted that not all subjects with PFAPA have the full spectrum of clinical findings embodied in the acronym. In areview of a large number of PFAPA patients,
- 60% to 90% of the patients had pharyngitis
- 53% to 93% cervical lymphadenitis,
- 27% to 57% aphthous stomatitis
- 40% tonsillitis
Describe the characteristic fever of PFAPA
The most distinctive feature of PFAPA is the clockwork periodicity of fevers with afebrile intervals of approximately 24 days. Most untreated fevers last 2–3 days and have average highs of 39.3– 40.1°
First line treatment in aborting fever during a fever flare from PFAPA
Low-dose corticosteroids are the most used first-line treatment in children with PFAPA and are very effective in reducing the duration of febrile episodes.
With the administration of asingle dose of corticosteroid(prednisone 1–2 mg/kg/dose, up to 25–60 mg, or betamethasone 0.1–0.2 mg/kg/dose) given early during the fever flare, fever will disappear within a FEW HOURS in more than 90% to 95% of patients, though some fatigue may remain for hours or days.
TIP: could be helpful diagnostically
Natural history of PFAPA
While most affected children will spontaneously recover from PFAPA over time, the effects of the illness on lifestyle and overall well-being usually require that medical management be instituted
Nolong-term complicationsof PFAPA have been reported so far.
Differential diagnosis of patient suspected to have PFAPA
Monogenic autoinflammatory fever syndromes (MAIDS), such as Familial Mediterranean Fever (FMF), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), and cryopyrin-associated periodic syndrome (CAPS) are important entities to be considered in the differential diagnosis of PFAPA.
How to dist between PFAPA and Monogenic autoinflammatory fever syndromes (MAIDS)?
Monogenic autoinflammatory syndromes are very rare, often life-long and chronic, and are progressive disorders associated with significant morbidity.
While associated with fevers, the fever pattern is usually irregular in those with FMF, TRAPS, and CAPS.
All three have detectable genetic abnormalities and, unlike PFAPA, have more prominent abdominal pain, diarrhea, vomiting, cutaneous rashes, and arthralgia.
What non-medical treatment can cure PFAPA?
In 2019, a Cochrane review of the benefits of surgery was published (see Abstract). The review observed that the risk ratio (RR) for the resolution of symptoms after surgery was 4.38 (95% confidence interval [CI] 0.64 to 30.11 [moderate-certainty evidence]).
There was no evidence that the addition ofadenoidectomyto tonsillectomy provided any greater benefit.
The role of routine tonsillectomy is a hotly debated topic even though the procedure has a high chance of “curing” the patient. T
What is the general difference between treponemal antibody tests and nontreponemal antibody tests in regards to what phase of the disease they may appear?
TIP: They are the opposites! They make up for what the other lacks!
Non treponemal: negative early in disease, late in disease and after treatment can seroconvert
Treponemal: present early in disease (earlier than nontreponemal), late in disease and even after treatment – LIFE LONG
What is considered a “discordant” test when using the reverse algorithm for syphilis testing?
Reverse algorithm means you start with a treponemal antibody test (EIA/CIA) then followed by a nontreponemal test (RPR or VDRL)
Discordant refers to POSITIVE treponemal test (EIA), but NEGATIVE nontreponemal test
What does the presence of “discordant” sera mean in regards to syphilis infection?
Basically, the 4 possibilities of a negative RPR
1) Previous treated infection in which the nontreponemal test has seroconverted
2) Early infection in which patient has not yet developed RPR Ab
3) Late infection in which patient has not been treated
4) False positive Treponemal Ab test
Remember:
TIP: They are the opposites! They make up for what the other lacks!
Non treponemal: negative early in disease, late in disease and after treatment can seroconvert
Treponemal: present early in disease (earlier than nontreponemal), late in disease and even after treatment – LIFE LONG
What is the solution to “discordant sera” when testing for syphilis?
Discordant:
- Treponemal Test (EIA/CIA) POSITIVE
Non treponemal Test (RPR/VDRL) NEGATIVE
Another treponemal Ab test like FTA-ABS or TPPA
What is the preferred treponemal test for “discordant sera” when testing for syphilis?
TPPA
Framework question:
Why is there an ammonia build up in HE?
3 major organs: Liver, Kidney and Muscle
Natural process: colonic bacteria break down protein -> nitrogen-containing compounds -> metabolized into ammonia in GI tract -> Ammonia enters liver -> urea cycle -> water soluble and non-toxic urea is excreted
In cirrhosis, 1) decreased hepatic function 2) decreased access to hepatocytes due to fibrotic sinusoids and 3) portosystemic shunting of ammonia rich blood away from gut/liver all lead to ammonia build up
How are the kidneys and muscles contributing to the pathogenesis of hepatic encephalopathy?
Kidneys need glutamine for 2 functions: acid base homeostasis and eukalemia.
In the setting of either acidosis or hypokalemia, the kidney uses glutamine to correct these disturbances. Glutamine, however, leads to ammonia as a byproduct.
Hence, any of these disturbances in the setting of liver failure, will add ammonia to the blood stream, in the setting of an already high ammonia state
Where is ammonia normally produced in the body?
In the gut as a normal part of digestion
Is asterixis pathognomic for HE?
NO
Occurs in uremia too
What other neurologic diseases does HE NOT mimic?
Stroke
Seizures
What neurogenerative disease can HE mimic?
Parkinson given the extrapyramidal dysfunction such as hypomimia (lack of facial expression), bradykinesia, muscle rigidity, tremor
What exactly is going on in asterixis?
It is NOT a tremor, but rather, a negative myoclonus, that is, loss of postural tone.
Hence when assuming an extended posture at the wrist, the flap is the loss of postural tone
Is HE an indication for liver transplant?
Yes, but only, recurrent and intractable HE.
Interesting: it would be difficult to pin a patient’s AMS’s only on HE and push toward transplant
How to use Ammonia blood level in the diagnosis of HE?
A high ammonia level does not add anything to the diagnosis of HE, but a low ammonia level brings into question the diagnosis of HE
How does Lactulose treat HE?
In addition to laxative effect, factors that may improve hepatic encephalopathy include prebiotic effects (nonabsorbable disaccharide is a prebiotic which promotes growth of beneficial microbiota), reduction (acidification) of colonic pH, reduced breakdown of nitrogen-containing compounds by bacteria, and interference with mucosal uptake of glutamine/ammonia in gut
What is the dosing and frequency of lactulose to treat overt HE?
25 ml lactulose every 1-2 hours until 2 soft BM’s are produced
Can rifaximin alone be used to treat HE?
No
Always used with lactulose
What is the first line treatment for HE?
Lactulose
Can any laxative be used to treat HE?
No
They lack the pre-biotic properties of lactulose and other disaccarhides
What are alternatives to treat HE if lactulose and Rifaximin are not working?
Branch chained amino acids
IV LOLA (L-ornithine L-aspartate)
Neomycin
Metronidazole