MISCELLANEOUS Flashcards
Probability that a sick patient will have a positive test
Sensitivity
Probability that a healthy patient will have a negative test
Specificity
of true positives + false negatives divided by total number of tests done
Prevalence
True negatives divided by true negatives + false positives
specificity
Having a high false psoitive rate will lowera tests ability to be
specific
1 standard deviation =
68% of samples are around the mean
2 standard deviation =
95% of samples are around the mean
3 standard deviation =
99.7% of samples are around the mean
Positively skewed distribution (mean median mode order)
mean > median > mode
Negatively skewed distribution (mean median mode order)
mode > median > mean
TYpe 1 error
null hypothesis is rejected when it is actually true
Probability of a type 1 error
alpha. Often the p-value set to 0.05 (5% chance of a type 1 error)
Type 2 error
null is accepted when it is actually false. False negative
Beta
Probability of a type 2 error. 1-beta is the POWER often set to 80%
Compare numerical means of two different groups - use what test?
unaired t etest
example: average BMI in sleeve vs bypass pts
Compare two different numerical measurements taken from a single group of patients
paired t test
example: BMI in pts before vs after getting a sleeve
compare numerical means of three or more groups
ANOVA
average BMI in sleeve vs bypass versus gastric band pts
Compare categorical outcomes between two or more groups
Chi square test or Fischers exact test
example does VTE occur more often in pts who are obese?
Identify and adjust for multiple potential factors contributing a to a categorical outcome
multivariate logistic regression
example: in a large database, determine what variables contribute to incidence of infection
Identify and adjust for multiple potential factors contributing to a numerical outcome
multivariate linear regression
example in a large database, determine what variables contribute to total lengthj of stay
identify difference in survivorship over time betwen two or mrore groups
kaplan-meie analysis
example: cancer survival in pts who received neoadjuvamnt versus adjuvant chemotherapy
analyze a population at a particular moment in time to determine prevalence of factors and disease
cross sectional study
population of subjects are analyzed to associate certain factors with an outcome
cohort study
cohort study can determine what kind of risk
relative
case control study are always prospective or retrospective
retrospective
case-control study used to predict RR or OR
odds ratio!
absolute risk
overall probability of the outcome
relative risk
probability of outcome in exposed group compared to probability of outcome in non exposed group
odds ratio
odds of outcome in exposed group compared to odds of outcome in non exposed group
relative risk reduction
proportion of decreased risk due to not being exposed
1 - relative risk
Number needs to treat
1 / absolute risk reduction
What do predictive values take into account that sensitivtiy and specificity do not
prevalence
Sudden hypotension with pneumoperitoneum in other wise healthy person is due to
decreased CO
IVC is compressed which decreases venous return and therefore decreases CO
What happens to functional residual capacity with pneumoperitoneum
Decreases
What happens to ADH with pneumoperitoneum
Increases. An increase in IAP leads to catecholamine release and activation of RAAS with vasopressin release
What happens to SVR and CVP with pneumoperitoneum
Increased
What happens to pH due to pneumoperitoneum
decreased
What happens to MAP and PAP and mean airway pressure with pneumoperitoneum
Increase
What does CO2 sometimes do to myocardial contracility
Decrease
Bipolar can achieve sealant of vessels of what size
< or = 7 mm
Power of a study calculated as
1 - beta (beta represents chance of incorrectly accepting the null hypotehseis when it is not true)
difference between two unpaired treatments using ordinal variables
Mann Whitney U test
example: two groups of pts, one is receiving a new narcotic and the other is receiving normal narcotic. difference in pain levels
ordianl variable
ranking scales or visual analog scale, such as pain scale
nominal variable
named category such as a persons favorite color
Comparing two unpaired treatments using quantitaitive variables
unpaired t test
assumes normal distrubtion
compare >2 treatments using quantiative variables
ANOVA test
Gastric staple line for sleeve gastrectomy should start where
6 cm from the pylorusN
Non parametric vs parametric data
Expected distribution of population is normal (parametric) or skewed (non parametric)
Non parametric test assessing qualitative data
Chi squared
Non parametric test assessing unpaired ordinal ONLY
Mann-Whitney U
Non parametric test assessing paired nominal variables only
McNemar
Non parametric test assessing paired ordinal data
Wilcoxon signed-rank test
Mann-Whitney-U test is also called
Wilcoxon rank SUM test
Quantitative data can be ___ or ___
disecrete or continuous
What happens to GFR with pneumoperitoneum
Decreases
Persistent reflux following gastrectomy (but do not want to have roux en y conversion)
magnetic sphincter augmentation badm
Decreasing the mangnitude of difference between groups will do what to teh power of the study
Decrease
Decreasing the standard error the mean will do what to the power of a study
Increase it
Preload with pneumoperitoneum
Decreases
when the piecemea ltechnique is used to remove a polyp when should repeat cscope be
2-6 months to document complete removal and no regrowth of polyp
relationship of splenic artery to pancreas
superior
relationship of splenic vein to the pancreas
within or posterior
tx of acute PID
rocephin 250 mg IM x 1 + doxy 100 mg BID x 14 days
MC site of perforation during cscope
sigmoid colon
when is rigid proctoscopy useful
when asesssing exact location of low rectal tumors for preoperative planning
where is ureter in relation to broad ligament
medial leaf
what type of suture is used in hysterectomy
heavy absorbable suture such as chromic gut or polyglycolic acid
what are howell-jolly bodies
nuclear remnants of RBCs only present if entirety of spleen removed OR in sickle cell
what are pappenhemier bodies
iron granules seen in increased frequency after splenectomy
what are siderocytes
abnormal RBCs with cytoplasmic inclusions and iron granules not part of normal RBC. Seen in post splnectomy pt
what are Heinz bodies
aggregates of denatured hemoglobin seen when using special dye such as crystal violet
MC seen in pts with G6PD and thalassemias
what is basophilic stippling
blue granules dispersed throughout cytoplasm of RBC which represent ribosomal precipitates
ost often seen in thalassemies, alcohol abuse, lead and heavy metal poisoning
MC benign neoplasm of the spleen
hemangioma
prophylactic abx in kids after splenectomy
until 5 years old or 2 years after splenectomy
pen V potassium 125 mg BID
how often EGD for familial polyposis
every 1-2 years
how often for EGD with gastric ulcer
every 6 weeks until healed
how often EGD for low risk Barretts
every 2 years
how often EGD for high risk Barretts
every year
how often for high risk Barretts with low grade dysplasia
every 6 months
how often EGD for esoph varices following sclerotherapy and banding
every 6-8 weeks
grade Ib endometrial CA
> 50% myometrial involvement
ITP and platelets >30K and asymptomator or minor bleeding tx
observation
ITP with platelets <30K and asymptomatic or minor bleeding
corticosteroids
urgent management of pt with ITP and bleeding or prior to urgent procedure
IVIG
where is b12 absorbed
distal ileum
circulatory collapse - seen in spinal shock or neurogenic shock
neurogenic shock
bradycardia - seen in spinal shock or neurogenic shock
neurogenic shock
peripheral vasodilation - seen in spinal shock or neurogenic shock
neurogenic shock
is bulbocavernosus reflex present in spinal shock or neurogenic shock
spinal
neurogenic shock can occur after SC injuries down to what level
T6
elevated ICP can cause a palsy of whic hcranial nerve
6th
results in lateral rectus weakness and side by side diplopia
when is ICP monitoring required
GCS = or <8 who EITHER have any CT evidence of intracrnial pathology OR normal CT with 2-3 of the following: age > 40 any hx of hypotension abnormal motor posturing
Consider in pt with GCS of < or =12 who cannot be closely monitored or whose CT demonstrates evidence of intracrnial HTN
hydroceles occur more often on which side
right
Brown sequard syndrome
ipsilateral motor loss
contralateral pain/temp loss
central cord syndrome
UE»_space; severely than LE
anterior cord syndrome sx
Loss of motor, pain and temp below level of lesion but preserved proprioception ,vibration and pressure sensation
cause of hydrocele
patent processus vaginalis with peritoneal fluid
after orchiectomy reveals stage I seminoama the next step is to obtain
serum tumor markers. If elevated may need RP XRT and or chemo
disruption of upper ureter or UPJ is repaired by
debridement and primary n anastomosis
use interupted 5-0 or 6-0 absorbable sutures and place a double J ureteral stent or nephrostomy before completion of anastomosis
early symptoms of uncal herniation
compression of CN III –> anisocoria, ptosis, impaired EOM, sluggish pupillary light reflex on ipsilateral side of lesion
gerotas fascia anterior and posterior leaves remain open in what direction
inferiorly, allowing ureter and gonadal vessels to exit
course of right renal artery in relation to IVC
posterior
rate of regeneration of typical axon
1-2 mm/day
MC site of renal cell CA metastasis
lung
CPP = ?
MAP - ICP
which ligament contains short gastrics
gastrosplenic
p[roteins responsible for opsonization
tuftsin and properdin
red pulp responsibilities
filters RBCs
most of the spleen
white pulp responsible for
immune function
lymphoid follicles in white pulp contain
b cells
periarterial lymphatic sheath in white pulp contain
T cells
target cell
immature RBC
spur cell
deformed membrane
most reliable finding in post splenectomy patients
howell jolly body (nuclear remnants)
MC hematologic disorders requiring splenectomy
ITP and spherocytosis
tx multi locular/thin walled splenic abscess
splenectomy as suspect echinococcal abscess
MC malignancy indication for splenectomy
non hodgkins lymphomas
ITP thought to be due to
autoantibodies to glycoproteins IIb/IIIa and Ia/IIa
when do you transfuse platelets in ITP
only for intraoperative bleeding
give after ligating splenic artery if possible as this prevents consumption of transfused platelets
presentation of hereditary spherocytosis
anemia, splenomegaly
dx of hereditary spherocytosis
autosomal dominant defect in cell membrane protein (spectrin) –> RBC less deformable –> culled by spleen
when is splenectomy recommended in hereditary spherocytosis
symptomatic patients older than 6 (want them to devo immune function first)
when performing splenectomy in hereditary spherocytosis what may also need done
cholecystectomy - check for gallstones, hemolysis produces bilirubin stones
what is pyruvate kinase deficiency
congenital hemolytic anemia caused by impaired glucose metabolism
what does splenectomy do in pyruvate kinase deficiency
reduces transfusion requirements
what hemoglobinopathy assoc with splenic abscess
sickle cell
tx of unilocular, thick walled splenic abscess
perc drainage
true splenic cyst (3)
congenital
parasitic (echinococcus)
neoplastic
false splenic cyst
post traumatic pseudocyst
tx of large >5 cm cysts or symptomatic splenic cyst
consider lap cyst excision or fenestration
splenic angiosarcoma assoc with
vinyl chloride and thorium dioxide exposure
mc primary non blood malignant tumor of spleen
angiosarcoma
tx of splenic angiosarcoma
splenectomy if caught in time
when to treat splenic artery aneurysm
> 2 cm
all pregnant women
women of child bearing age regardless of size (up to 70% rupture risk during pregnancy)
tx of splenci artery aneurysm
endovascular coil embolization or placement of covered stent
open or lap splenic artery ligation also acceptable
very distal splenic artery aneurysm tx
may require splenectomy
pathogenesis of post splenectomy infection
decreased IgM and IgG leads to increased susceptibility to encapsulated organisms
prophylactic abx after splenectomy
cosnider in children <10 years old for 6 month duration (daily Augmentin)
how to diagnose accessory spleen
radionuclide spleen scan (tagged RBC scan)
MC organism assoc with OPSI
S pneumo
wandering spleen is caused by
failure of fusion of dorsal mesogastrium leading to lack of splenci ligaments
tx of wandering spleen
splenectomy if infarcted
otherwise splenopexy
pentad of TTP
fever hemolytic anemia renal failure purpura neuro changes FAT RN
TTP due to
defective ADAMTS13 metalloproteinase (vWF cleaving protein) –> platelet aggregation in microvasculature
Loss of platelet inhibition
tx of TTP
plasmapheresis
what is “pitting” in red pulp
removal of abnormalities in RBC membrane
what is “culling” in red pulp
removal of less deformable RBC
largest producer of IgM
spleen
MC antibody in spleen
IgM
which opsonin facilitates phagocytosis and where is it produced
tuftsin
spleen
which protein produced in spleen activates alternate complement pathway
spleen
MC non traumatic condition requiring splenectomy
ITP
spleen in ITP is
normal
in children <10 years describe course of ITP
usually resolves spontaneously
primary tx of ITP
steroids
gammaglobulin if resistant
death in TTP is most commonly due to
intracerebral hemorrhage or acute renal failure
Most PSSS occur within what time period after splenectomy
2 years
definition of hypersplenism
decrease circulating cell count of erythrocytes and/or platelets and/or leukocytes
AND
normal compensatory hematopoietic responses present in bone marrow
AND
correction of cytopenia by splenectomy
+/-
splenomegaly
spectrin and protein 4.1 deficit
elliptocytosis
similar to spherocytosis less common
MC congenital hemolytic anemia NOT involving membrane protein that requires splenectomy
pyruvate kinase deficiency
G6PD deficiency precipitated by
infectrion
certain drugs
fava beans
MC autoimmune hemolytic disease
warm antibody-type acquired immune hemolytic anemia
HgbA replaced by HgbS
sickle cell anemia
splenectomy in beta thalassemia
if pt has splenomegaly
may decrease hemolysis and symptoms
beta thalassemia is due to
persistent HgbF
Medical tx of beta thalassemia
blood txn, iron chelators such as deferoxamine and deferiprone
Stage 1 Hodgkin’s
1 area or 2 contiguous areas same side of diaphragm
Stage II Hodgkins
2 non contiguous areas on same side of diaphragm
Stage III Hodgkins
involved on each side of diaphragm
Stage IV hodgkins
liver, lung, bone or any other non lymphoid tissue except spleen
best prognosis hodgkins
lymphocyte predominant
worst prognosis hodgkins
lymphocyte depleted
reed sternberg cells
hodgkins
most common hodgkins
nodular sclerosing
workup for hodgkins
1) core needle biopsy of lymph node
2) bone marrow biopsy
3) gallium MRI or PET scan of liver and spleen
90% of NHL
B cell lymphomas
Better prognosis - NHL or HL?
HL
hairy cell leukemia + splenectomy
rarely
what is splenosis
splenic implants usually related to trauma
MCC splenic artery or splenic vein thrombosis
pancreatitis
if platelets >1 x 10^5 after splenectomy give
ASA
1 malignant splenic tumor
NHL
MCC splenomegaly
NHL
Feltys syndrome
RA, hepatomegaly, splenomegaly, and pancytopenia
tx of Feltys syndrome
MTX
splenectomy for symptomatic splenomegaly
MCC splenic abscess
Streptococcus
Tx of dermoid splenic cyst
splenectomy
Persistent changes in splenectomy
lymphocytosis, monocytosis
transient changes after splenectomy on CBC
thrombocytosis, leukocytosis
beta blocker overdose tx
atropine and IVF
if refractory: glucagon
post operative parotitis is most likely due to
staph aureus
most significant factors influencing oxygen content of bloo
Hgb and Hct
Oxygen content equation
CaO2 = (Hgb x 1.34 x 02 sat) + (0.003 x PaO2)
benefit in treatment of refractory small bowel AVM
thalidomide
During first 24 hrs of stress/starvation,o organ with highest glycogen stores
liver
AT III deficiency – what can you give?
FFP
predominant collagen in the body
type I
principal collagen in scars
type I (with lesser amounts of type III collagen also present)
Proliferative phase of wound healing is characterized by
angiogenesis and collagen production
MCC of lower GIB in AIDS
CMV
IL-2 is secreted by
T lymphocytes
IL-4 role
induces naive T helper cells to become T heloper 2 cells
Involved in adaptive immunity
what cytokines do macrophages release in early stages of wound healing
IL-1
IL-6
IL-8
TNF-alpha
what part of the gram negative cell wall is potent stimulator of the release of proinflammatory cytokines
lipid A
MCC of emphysematous cholecystitis
Clostridia
What type of bacteria are Clostridia spp
anaerobic gram + rods
Protein parameters in ESRF
1.2-1.5 g/kg/day
Li fraumeni is defined as having all 3:
Proband diagnosed with sarcoma before 45 yo
First degree relative with any CA diagnosed before age 45
An additional 1st or 2nd degree relative with either sarcoma at any age or any cancer before the age of 45 years
VHL
renal cell CA
emangioblastomas of retina and CNS
pheochromocytoma
HBsAg-
Anti-HBc +
Anti-HBs +
immune due to natural infection
HBsAg +
Anti-HBc +
Anti-HBs -
Acutely infected
Will also have + IgM anti-HBc
HBsAg + or -
Anti-HBc +
Anti-HBs +
Chronically infected
HBsAg -
Anti-HBc +
Anti-HBs +
Resolved infection
MCC cholangitis
E coli > Klebsiella > Enterococcus
Secondary lymphoid organs
LN
Spleen
Peter patches
Tonsils
Adenoids
Primary lymphoid organs
Liver
Bone
Thymus
False positive rate of PET in mediastinal malignancy
10-20%
Visceral pain is
vague, non specific pain
Localization of pain in appendicitis occurs due to
somatic fiber irritation
which amino acid associated with immune enhancement by stimulation of T lymphocytes
arginine
predominant cell during proliferative stage
fibroblasts, responsible for collagen production and secretion
MC gram negative a/w VAP
Pseudomonas aeruginosa
MC gram positive a/w VAP
Staph aureus
MOA streptokinase
binds to plasminogen and increases plasmin production
Cytokine associated with cachexia
TNF-alpha
Sx of copper deficiency
pancytopenia, peripheral neuropathy, ataxia
MOA of ticagrelor
REVERSIBLE platelet aggregation inhibitor
non competitively binds to diphosphate (ADP) P2Y12 receptor on platelets to prevent activation of the GPIIB/IIIA receptor complex
MOA enterococci resistance to gentamicin
genetic mutation for production of modifying enzymes
predominant cell type in healing wound 24-48 hours after initial injury
neutrophil
human breastmilk contains large amounts of which immunoglobulin
IgA
primary means by which newborn remains protected during first 6 months of life
combo of maternal IgG (crosses placenta) and secretory IgA which is passed through breast milk
tamoxifen MOA
estrogen agonist in non breast tissues
competitive estrogen antagonist in the breast
Plavix - what works best for reversal of coagulopathy
platelets
deficiency of complement proteins C5-C9
reduced arterial cell lysis due to difficulty in formation of the MAC
branched chain amino acids
leucine
isoleucine
valine
post translant lymphoproliferative distorder is due to
immortalization of EBV + B cells
first line pix for type I vWD who are undergoing surgery is
DDAVP
Which vWD type is DDAVP not effective
Type III
mechanism behind factor V leiden
activated protein C resistance
Factor V is usually ianctivated by an activated protein C
during wound healing when does maximum accumulation of collagen occur
21 days
how does amphotericin B act to prevent fungal growth
binds to fungal cell wall sterols and causes cell death via lysis
greatest art of protein turnover occurs where
skeletal muscle
milrinone moa
PDE 3 inhibitor
expected excess weight loss 2 years following RYGB
60%
weight loss/excess weight (actual weight and ideal weight)
flumazenil dose
0.2 mg IV up to 3 mg
complication of meperidine
seizure
in renal transplant renal artery and vein are typically anastomosed to what
end to side to EIV and EIA
simultaneous kidney and pancreas transplant - anastomosis?
kidney uses left iliac vessels andp ancreas anastomosed to right iliac vessels
MC indication for renal transplant
DM II
1st line treatment for PTLD
Rituximab
monoclonal antibody
cowdry bodies
eosinophilic inclusion bod
imnmediate allergic reactionsto cephalosporins are mediated by
IL-4 inducedp roduction
treatment of symptomatic pancreatc divisum
ERCP with sphincterotomy
what should you check prior to starting EPO in CKD
iron (MC reason for failure)
MCC of long term lung transplant graft failure
bronchiolitis obliterans
