Absite review Flashcards
Heparin MOA ?
Heparin activates AT-III (up to 1000× normal activity).
AT-III MOA ?
Inhibits Thrombin, factor 9,10 and 11
Protein C & S MOA ?
protein c degrades factor 5 and 8 and fibrinogen
protein S is a cofactor for protein c
Only factor not synthesized in the liver?
factor 8
DDAVP function?
Causes the release of vwf and factor 8 from the endothelium
cryoprecipitate content?
has the highest concentration of vWf and factor8
Heparin-induced thrombocytopenia (HIT) pathophysiology
Thrombocytopenia due to anti-heparin antibodies (IgG heparin-PF4
antibody) results in platelet destruction
patients with coronary stents and on plavix the need to undergo surgery what do u do?
you can stop plavix 7 days prior to surgery and bridge the patient on eptifibatide [GpIIb/IIIa inhibitor]
ε-aminocaproic acid MOA ?
inhibits fibrinolysis
the best way to detect bleeding risk prior to surgery is through?
history and physical exam
factor V leiden mutation pathophysiology?
defect on factor V makes it resistant to activated protein C
Most common cause of acquired hypercoagulable state is ?
Smoking
Dabigatran (pradaxa) MOA ?
Direct thrombin inhibitor
Tx of HITT (Heparin Induced Thrombocytopenic Thrombosis) ?
STOP the heparin and add Argatroban (direct thrombin inhibitor)
MCC of death from transfusion reaction?
TRALI (Transfusion related Acute Lung Injury)
Most abundant antibody is ?
IgG
Type 1 hypersensitivity reaction example ?
bee stings, penut allergy, hay fever
Type 2 hypersensitivity reaction example?
ABO incompatibility
Hyperacute rejection
myasthenia gravis
Type 3 hypersensitivity
reaction example?
serum sickness
SLE
(immune complex deposition)
What are tetanus prone wounds ?
(> 6 hours old; obvious contamination and
devitalized tissue; crush, burn, frostbite, or missile injuries)
when to give tetanus immunoglobulin in addition to vaccine?
(given intramuscular near wound site) – give
only with tetanus-prone wounds in patients who have not been immunized
or if immunization status is unknown
Most common immunodefeciency leading to infection is ?
Malnutrition
Most common anaerobe in the colon ?
Bacteroides Fragilis
Most common aerobic bacteria in the colon?
E.coli
Arrange fever causes sequentially over time
Fever sources (sequentially over time) – atelectasis, urinary tract
infection, pneumonia, DVT, wound infection, intra-abdominal abscess
Most common organism overall in surgical site infections
Staph aureus
Most common GNR in surgical wound infections
E.coli
most common aneorobe in surgical wound infections
Bacteroides Fragilis
Risk factor for SSI ?
Surgical factors: Long operations, Hemtoma or seroma formation
Patient factors: Advanced age, chronic disease, malnutrition, DM, Imunnosuppressive medication
Organisms associated with Necrotizing fascitis?
Beta henolytic (group A) strep
MRSA
characterisitc gram stain for Actinomyces?
Yellow sulfur granules on gram stain
MCC of fungemia?
Candida
Diagnosis of Spontaneous Bacterial peritonitis?
peritoneal fluid with PMN >250 or positive culture (50% ecoli, 30% streptococcus, 10% klebsiella)
Most common indication for liver transplantation is ?
Hepatits C
MC site of aspiration pneumonia in lungs?
superior segment of the right lower lobe
What are the bacteriostatic antibiotics?
tetracycline, clindamycin, erythromycin (all
have reversible ribosomal binding),
TMX-SMZ
Most common method of antibiotic resistance?
Transfer of plasmid
MCC of intraop bradycardia
inhalational anasthesia
which inhalational agent in anasthesia is good for neurosurgery?
Isoflurane – good for neurosurgery (lowers brain O2 consumption; no
increase in ICP)
last muscle to go down and 1st muscle to recover from
paralytics
Diaphragm
1st muscle to go down and last muscle to recover from paralytics
Muscles of the neck and face
which muscle relaxant undergoes hoffman elimination(elmination in blood and tissues)?
Cis-atrcurium
which muscle relaxant is the fastest?
Rocuronium
sugammadex reversal agent for which muscle relaxnats?
Rocuronium
Vecuronium
Maximum dosing of local anasthetics?
- Lidocaine 4 mg/kg (7 mg/kg with epi)
- Bupivacaine 2 mg/kg (3 mg/kg with epi)
Amides (all have an “i” in first part of the name)
lidocaine,
bupivacaine, mepivacaine; rarely cause allergic reactions
Esters of local anasthetics
tetracaine, procaine, cocaine; ↑ allergic reactions due to PABA
analogue
Opiods MOA?
CNS mu-receptor agonists
Combination of MOAI and opiods can lead to?
hyperpyrexic coma (serotonin release syndrome – fever,
tachycardia, seizures, coma)
Epidural insertion site for thoracotomy vs laparatomy?
Thoracotomy insertion level: T6–T9
Laparotomy insertion level: T8–T10
how to calculate serum osmolarity?
(2*NA)+(gluscose/18)+(BUN/2.8)
normal value (280-295)
Insensible fluid loss
10 cc/kg/day; 75% skin (#1; sweat), 25%
respiratory, pure water
GI fluid secretions amount for stomach, duodenum, pancreas and biliary system
● Stomach 1–2 L/day
● Biliary system 500–1,000 mL/day
● Pancreas 500–1,000 mL/day
● Duodenum 500–1,000 mL/day
highest concentration of potassium the body is in?
SALIVA
You need to replace Magnesium before correcting what electrolytes?
Potassium and calcium
Symptoms of hypernatremai?
PATIENT is HYPER :D
he is restless and irritable and is having seizures
Tx of refractory and severe SIADH?
conivaptan, tolvaptan (competitive
antagonist for kidney V2 receptor)
High anion gap acidosis causes?
“MUDPILES” = methanol, uremia, diabetic ketoacidosis, paraldehydes,
isoniazid, lactic acidosis, ethylene glycol, salicylates
Whats increases caloric needs ?
trauma sepsis surgery
burn
pregnancy
lactation
How to calculate calories and protein for burn patients?
- Calories: 25 kcal/kg/day + (30 kcal/day × % burn)
- Protein: 1–1.5 g/kg/day + (3 g/day × % burn)
- Don’t exceed 3,000 kcal/day.
Fuel for small bowel eneterocytes?
glutamine
fuel for colonocytes?
short chain fatty acids
obligate glucose users?
Blood, Renal medulla, Brain, Bone marrow
Glycogen stores can supply the body with glucose for how long ?
12-24hours
Preoperative low serum albumin is associated with postoperative
increase mortality and morbidity
The best acute indicator of nutritional status is ?
prealbumin
Harris–Benedict equation calculates basal energy expenditure based on what parameters?
Age,height, weight and gender
Preooperative nutrition is indicated in ?
indicated only for patients with severe malnutrition
undergoing major abdominal or thoracic procedures.
At what day symptoms of refeeding syndrome usually after after initiating feeding?
Day 4
what are micelles?
ggregates of bile salts, long-chain free fatty acids, and
monoacylglycerides
* Enter enterocyte by fusing with membrane
* Bile salts – increase absorption area for fats, helping form micelles
* Cholesterol – used to synthesize bile salts
* Fat-soluble vitamins (A, D, E, K) – absorbed in micelles
Essential fatty acids
linolenic, linoleic
Non-essential amino acids
those that start with A, G, or C plus serine, tyrosine,
and proline
METABOLIC SYNDROME (NEED 3 to diagnose)
● Waist circumference (> 40 inches in men, > 35 inches in women)
● Insulin resistance (fasting glucose > 100)
● High TAGs (> 150)
● Low HDL (< 40 in men, < 50 in women)
● Hypertension(>130/85)
Most important prognostic indicator for lung CA and breast CA
nodal status
Most important prognostic indicator for sarcoma
Tumor grade
testicular CA, choriocarcinoma tumor marker
B-HCG
folinic acid with methotrexate vs 5FU
with methotrexate its reverse the effect
with 5FU it augments the effect
Cisplatinum s/e
nephrotoxic, neurotoxic and ototoxic
chemotheraputic agents that causes myelosuppression
vinblastine
carboplatin
prophylactic thyroidectomy is done in
patients with RET proto-oncogene with familt history of thyroid CA
examples of tumor suppressor genes
RB1
APC
p53
DCC
BRCA
bcl
Li–Fraumeni syndrome
defect in p53 gene → patients get childhood
sarcomas, breast CA, brain tumors, leukemia, adrenal CA
Cowden syndrome
defect in PTEN gene; get benign hamartomas
(skin, mucus membranes, GI tract); increased risk for CA (usually
thyroid, breast, and endometrial CA)
Hereditary diffuse gastric cancer
Defect in CDH1 gene
Genes involved in colon CA
APC, p53, DCC, and K-ras.
which type of cancer metastasise to small bowel
melanoma
Most common malignancy following transplant?
Skin cancer (Squamous skin cancer)
2nd MC malignancy following transplant?
Posttransplant lympho-proliferative disorder (PTLD) – next most
common malignancy following transplant (Epstein-Barr virus related)
Azathioprine and mycophenolate MOA
Inhibits de novo purine synthesis, which inhibits growth of T cells
Cyclosporine MOA?
Binds cyclophilin protein; CSA-cyclophilin complex then inhibits
calcineurin, which results in decreased cytokine synthesis (IL-2 most importantly)
FK-506 (Prograf, tacrolimus) MOA?
Binds FK-binding protein; actions similar to CSA but more potent
Sirolimus MOA ?
Binds FK-binding protein like FK-506 but inhibits mammalian
target of rapamycin (mTOR); result is that it inhibits T and B cell
response to IL-2
Anti-thymocyte globulin (ATG) MOA?
polyclonal antibodies
against T-cell antigens (CD2, CD3, CD4)
* Used for induction and acute rejection episodes
Side effect profile of Anti-thymocyte globulin (ATG)
Side effects:
*cytokine release syndrome (fever, chills, pulmonary
edema, shock) – steroids and Benadryl given before drug to try to
prevent this
*PTLD
*Myelosuppression
You can store the kidney before transplant for how long ?
48 hours
Most common complication following kidney transplant?
urine leaks
New proteinuria post kidney transplant suggest?
renal vein thrombosis
you can store liver for how long before transplantation?
24 hours
Most common reason for liver transplant?
chronic hep C
The most common complication post liver TXP?
biliary complications (bile leak)
The most common vascular complication following liver TXP?
Hepatic artery thrombosis
histopathology following acute rejection of liver transplant
portal triad lymphocytosis, endotheliitis
(mixed infiltrate), and bile duct injury
histopathology following chronic rejection of liver transplant
disappearing bile duct phenomenon
indication of of heart and lung transplant
those with life expectancy of less than 1 year
MCC of late death and death overall following heart TXP
Chronic allograft Vasculopathy (progressive diffuse coronary atherosclerosis)
MCC of late death and
death overall following lung TXP
bronchiolitis obliterans
Function of c-reactive protein?
an opsinon, activates complement
Chemotactic factors for inflammatory cell
PDGF, PAF, IL-1, TNF-a, IL-8, C3a, C5a, LTB-4
chemotactic factors for fibroblasts
FGF, EGF, PDGF
Angiogenesis factors
PDGG, EGF, FGF, IL-8
Epithelisation factors
PDGF, EFG, FGF
cause of fever in inflammatory response
IL-1
interleukin that increases acute phase reactant production
IL-6
IL-8 function
PMNs chemotaxis, Angiogenesis
IL-10 function
Decreases the inflammatory response
Activator of the classic complement pathway
Antigen-antibody complex
Alternative complement pathway is activated by
bacteria, endotoxin and other stimuli
complement factors present only in classical pathway
C1, C2, C4
factors found only in alternative complement pathway
Factors B, D and P
Factor that is common for both complement pathway
C3
which factors are responsible complement opsinization
C3b, C4b
Membrane attack complex is made up of what factors
C5b, C6b, C7b, C8b, C9b
The primary mediators of reperfusion injury
PMNs
Stages of wound healing
1-Homeostasis and inflammation (1-10 days)
2-proliferation (5 days-3 weeks)
3-Remodelling (3 weeks- 1 year)
Epithelialization rate?
1-2 mm/ day
Order of cell arrival in wound healing
- Platelets
- PMNs
- Macrophages
- Lymphocytes (recent research shows arrival before fibroblasts)
- Fibroblasts
Strength layer of bowel
submucosa
leakage of large amounts of pink “salmon-colored”
fluid from wound indicates
Wound dehiscence
why anastomotic leaks in the gastrointestinal
tract occur with increased frequency days 3-5 post anastamosis?
increased collagenase
activity in the small bowel allows collagen breakdown
to exceed collagen Deposition on Days 3 to 5 after an anastomosis
Type 2 collagen found in?
Car(two)llage
Type 4 collagen found in ?
Basement membrane
Type III replaced by type I collagen by at which week of wound healing
End of proliferative phase (week 3)
Ehlers-Danlos is a spectrum
of connective tissue disorders that can affect multiple types
of collagen but the most common is
Type V collagen
Osteogenesis imperfecta type of collagen defect
Type 1 collagen defect
Seat belt sign is concerning for what injuries
small bowel, pancreatic, lumber spine fractures and sternal fractures
what defines massive blood transfusion
patients receiving ≥ 4 units pRBCs in the
first hour or ≥ 10 units pRBCs within 24 hours
POSTIVE DPL ?
Positive if > 10 cc blood, > 100,000 RBCs/cc, food particles, bile, bacteria, > 500 WBC/cc
Patient with Flank stab wound and stable what to do next?
possible injury to retroperitoneal contents (eg colon, kidney, ureter)
* Dx: abdominal CT scan with oral, rectal, and IV contrast (triple contrast)
Resuscitative thoracotomy indications (ED thoracotomy)
- Penetrating trauma (resuscitative thoracotomy indicated for any below):
1. CPR was started within 15 minutes of a penetrating thoracic injury.
2. CPR was started within 5 minutes of a penetrating extra-thoracic injury (eg
penetrating abdominal trauma).
3. Patient had signs of life and pulse or pressure was lost (SBP < 60) on way to ED or in
ED. - Blunt trauma – resuscitative thoracotomy only if pressure or pulse lost in ED (CPR
started within 5 minutes)
The most important prognostic indicator in the GSC
Motor response
Coagulopathy with traumatic brain injury is due to
tissue thromboplastin release
Most common cause of facial nerve injury in trauma
Temporal bone fractures
Hardest neck injury to find ?
esophageal injury
Criteria for massive hemothorax that will need emergent thoracotomy
> 1,500 cc after initial insertion, > 200 cc/h for 4 hours, > 2,500 cc/24 h, or bleeding with
instability
Unresolved hemothorax (retained hemothorax) after 2 well-placed chest tubes Tx
VATS drainage
Persistent pneumothorax despite 2 well-placed chest tubes
Dx: bronchoscopy (look for
mucus plug or tracheobronchial injury)
sucking chest wound (open pneumothorax) initial management ?
Cover wound with dressing that has tape on three sides → prevents development of
tension pneumothorax while allowing lung to expand with inspiration
Flail chest definition?
≥ 2 consecutive ribs broken at ≥ 2 sites
what can u see on CXR in diaphragmatic injury
see air–fluid level in chest from stomach herniation through hole
most common site of aortic tear after trauma
proximal descending thoracic aorta at the ligamentum
arteriosum (just distal to left subclavian takeoff)
highest risk factor for myocardial contusion?
sternal fracture
boarders of cardiac box in penetrating chest injuries?
Clavicle, nipples and xiphoid process
MC mechanism for duodenal trauma?
Blunt trauma (crush, deceleration injury)
MC portion of the duodenum to be injured?
2nd part of the duodenum
MC portion of duodenum to develop hematoma following trauma
usually in third portion of
duodenum overlying spine in blunt injury
best study for diagnosing suspected duodenal injury
UGI study
Right colon and transverse colon injuries Tx
Tx: 1) primary repair or 2) resection and anastomosis
(for destructive injuries [ie > 50% circumference or associated with significant colon
devascularization]); all are essentially treated like small bowel injuries.
* No diversion needed for right and transverse colon injuries
Bed rest time with nonoperative management with splenic and liver injuries
5 days
postsplenectomy sepsis greatest risk within
first 2 years
Most important aspect of pancreatic trauma
Figuring out whether pancreatic duct is injured or not
Hard signs of extremity vascular injuries
- Active bleeding
- Distal ischemia
- Absent distal pulses
- Expanding/pulsatile hematoma
- Bruit or thrill
Soft signs of extremity vascular injuries?
- History of bleeding
- Unequal pulses
3.Nonexpanding/nonpulsatile hematoma - ABI <0.9
Retroperitoneal zones of trauma
Zone 1 (Central retroperitoneum)
Zone 2 (Flank)
Zone 3 (pelvis)
Triad of Hemobilia
RUQ pain, Jaundice and Melena
percentage of Cardiac output to kidneys, brain and heart
kidney 25%
brain 15%
heart 5%
Cardiac index
CO/Body surface area
Anrep effect
automatic increase in contractility secondary to increase afterload
bowditch effect
automatic increase in contractility secondary to increase in heart rate
Causes of right shift of oxygen–Hgb dissociation curve (increased O2 unloading)
↑ CO2 (Bohr effect) ↑ temperature, ↑ ATP production, ↑ 2,3-DPG production, or
↓ pH
Becks triad
muffled heart sound, jugular venous distension, Hypotension
presentation of ventilated patients with PE
decrease ETCO2 and hypotension
Intra-aortic balloon pump is used in
cardiogenic shock
MOA of IABP
inflates on diastole and deflates on systole which decreases the afterload and increase diastolc coronary perfusion
Beta 2 receptors
Relaxes bronchial smooth muscle, relaxes vascular smooth muscle;
increases renin
Dobutamine MOA
Beta 1 agonist
phenylephrine MOA
Alpha 1 agonist (vasoconstriction)
Norepinephrine MOA
Alpha-1 and alpha-2; some beta-1 agonist
Epinephrine MOA
- Low dose – beta-1 and beta-2 (↑ contractility and vasodilation)
Can ↓ BP at low doses - High dose – alpha-1 and alpha-2 (vasoconstriction)
Vasopressin MOA
V1 receptor: Arterial vasoconstriction
V2 receptor (intrarenal): increase water reabsorption collecting ducts
V2 receptors (extrarenal): Increase release of Factor 8 and VWF
Nipride (arterial vasodilator) main toxicity
cyanide toxicity
Nitroglycerine MOA
predominately venodilation with ↓ myocardial wall tension from ↓
preload; moderate coronary vasodilator
Hydralazine MOA
alpha blocker lowers BP
Criteria for ARDS
.Acute onset
.Bilateral pulmonary infiltrates
.PaO2/FIO2 ≤ 300
.Absence of heart failure (wedge < 18 mm Hg)
best predictor of extubation
rapid shallow breathing index
plateau pressure is an index of
alveolar pressure
peak pressure is an index of
large airway pressure
what does PEEP increase in pulmonary lung measurements
increases FRC
Mendelson syndrome
chemical pneumonitis from aspiration of gastric content
MCC of postop renal failure
intraop hypotension
prerenal failure urine osmolality and FeNA%
> 500
<1%
Prerenal BUN:Cr ratio
> 20
SIRS criteria
*Temp > 38 or <36
*HR >90
*RR> 20 or PaCo2 <32
*WBC >12,000 or <4000
difference between second degree burn superficial (papillary) and deep (reticular)?
in superficial there is NO loss of hair follicles and NO need for skin grafts
Admission criteria for burns
● 2nd- and 3rd-degree burns > 10% BSA in patients aged < 10 or > 50 years
● 2nd- and 3rd-degree burns > 20% BSA in all other patients
● 2nd- and 3rd-degree burns to significant portions of hands, face, feet, genitalia,
perineum, or skin overlying major joints
● 3rd-degree burns > 5% in any age group
● Electrical and chemical burns
● Concomitant inhalational injury, mechanical traumas, preexisting medical conditions
● Injuries in patients with special social, emotional, or long-term rehabilitation needs
● Suspected child abuse or neglect
MC type of burn
scald burn
Escharotomy indications
- Circumferential deep burn to the extremitis that can affect blood supply
*Chest torso/ neck burns that can affect ventilation
*suspected increase in abdominal compartment pressure in torso burns
most common infection and death in patients with > 30% BSA
pneumonia
indications for intubation in inhalational burn injuries
*upper airway obstruction (stridor)
*worsening hypoxemia
*Patient expected to have massive fluid resuscitation (can worsen symptoms)
Acid and alkali burns initial management
copious water irrigation
hydrofluoric acid burn initial management
spread calcium on wound
which is worse acid or alkali burn
alkali is WORSE liquefaction
necrosis.
Acid burns produce coagulation necrosis.
blood supply to grafts day 0-3
imbibition (osmotic)
blood supply to grafts after day 3
neovascularization
Most common reason for skin graft loss
Seroma or hematoma formation under the graft
clinical difference between STSG and FTSG
- STSGs are more likely to survive – graft not as thick so easier for imbibition and
subsequent revascularization to occur - FTSGs have less wound contraction – good for areas such as the palms and back of
hands
MC organism in burn wound infection
pseudomonas followed by staph
silver sulfadiazine used for burns side effects ?
neutropenia and thrombocytopenia
(do not use in sulfa allergy)
Silver nitrate ointment for burn s/e
electrolyte imbalance (hypo-everything :))
do not use in G6PD
can cause methglobulinemia
best burn ointment for MRSA infection
Mupirocin
sulfamylon ointment burn wound s/e
painfull application
can cause metabolic acidosis
Some signs of burn wound infection
*conversion of 2nd to 3rd degree burn
*accelerated eshcar seperation
Gold standard method to detect burn wound infection
burn wound biopsy
MCC of pedicled or anastomosed free flap necrosis
venous thrombosis
pressure sores stages
stage 1 : Erythema and pain with no skin loss
Stage 2 : Partial skin loss into the dermis
Stage 3: Full thickness skin loss where subcutaneous fat is exposed
Stage 4: bone, muscle, tendon is exposed
Most lethal skin cancer
Melanoma
most common melanoma site on skin
back in men
legs in women
MC location of distant metastasis in melanoma
Lung
Most aggressive type of melanoma
Nodular type
MC type of melanoma
Superficial spreading type
MC skin malignancy
Basal Cell Carcinoma
main amino acid used as gluconeogenesis precursor
Alanine
appearance of Basal cell CA
pearly appearance with rolled border ulcer
actinic keratosis is a risk factor
squamous cell CA
MC soft tissue sarcoma
malignant fibrous histiosarcoma
spread of sarcoma through which route
hematogeneous route
Most important prognostic factor for sarcomas
Tumor grade
MC soft tissue sarcoma in children
rhabdomyosarcoma
Anterior neck triangle contains
carotid sheath
posterior neck triangle contains
accessory nerve and brachial plexus
vagus nerve course
runs between internal jugular vein and common carotid artery
phrenic nerve course
runs on top of the anterior scalene muscle
long thoracic nerve course
run posterior to the middle scalene muscle
Recurrent laryngeal nerve innervates
all of the larynx except cricothyroid muscle which is innervated by the superior laryngeal nerve
Frey’s syndrome is caused by damage to which nerve
auriculotemporal nerve
Thyrocervical trunk branches
Think STAT
(Suprascapular, Transverse cervical, Ascending cervical,
inferior Thyroid artery)
1st branch of the external carotid artery
superior thyroid artery
MC cancer of the oral cavity, pharynx and larynx
Squamous cell CA
MC malignant tumor of the salivary glands
mucoepidermoid CA
MC tumor overall of the salivary glands
pleomorphic adenoma (benign tumor)
angioembolisation is done for which arteries in posterior nose bleeds
internal maxillary or ethmoidal arteries
facial nerve branches
temporal
zygomatic
maxillary
marginal mandibular
cervical
MC injured nerve with parotid surgery
greater auricular nerve
MC location of esophageal foreign body
just below the circopharyngeus muscle
posterior pituitary secretes
ADH, oxytocin
hypothalamus secretes what hormones
CRH,GHRH,GnRH,TRH,
Dopamine
anterior pituitary secretes
ACTH, TSH, LH, FSH, GH, Prolactin
what hormone is elevated in acromegaly
elevated IGF-1 (best test)
Nelson’s syndrome
- Occurs after bilateral adrenalectomy; ↑ CRH causes pituitary
enlargement, resulting in amenorrhea and visual problems (bitemporal
hemianopia) - Also get hyperpigmentation from beta-MSH
