absite killer plus - Sheet1 Flashcards
What is the source of fever in atelectasis?
Alveolar macrophages
What is the first sign of malignant hyperthermia?
Increase in end-tidal CO2
What is the treatment for malignant hyperthermia
Dantrolene
What is the first muscle to recover from paralytics?
Diaphragm
What is the rate-limiting step in cholesterol formation?
HMG coA Reductase
Where is angiotensin I converted into angiotensin II?
lung
What are the effects of angiotensin II?
Vasoconstriction Increases aldosterone (keeps Na, loses K/H in urine)
Describe the anatomy of the vagus innervation of the stomach
Left vagus (anterior) gives hepatic branch, Right (posterior) gives celiac branch and “criminal nerve of Grassi”
Which cells produce pepsinogen?
Chief cells
Which cells produce intrinsic factor?
Parietal cells
What are the main stimuli for H+ production in the stomach?
Acetylcholine, gastrin, and histamine
What is the mechanism of omeprazole?
Blocks H/K ATPase of parietal cell
What is the most common symptom post-vagotomy?
Diarrhea (35%)
What is the cause of early (15-30 min) dumping syndrome?
Hyperosmotic load, fluid shift causes neuroendocrine response, peripheral and splanchnic vasodilation
What is the cause of late (2-3 hrs) dumping syndrome?
Increased insulin with decreased glucose
What are the 3 actions of CCK?
1) contract gallbladder 2) Relax Sphincter of Oddi 3) Increase pancreatic enzyme secretion
What is the primary stimulus of pancreatic bicarb secretion?
secretin
What affects the amount of bicarb in pancreatic secretions?
Flow rate: high flow = high bicarb, low Cl. Slow flow allows more HCO3/Cl exchange
Describe the phases of the migratory motor complex
Phase I - quiescence; Phase II - acceleration, gallbladder contraction; Phase III - peristalsis; Phase IV - subsiding electric activity; occurs in 90 min cycles
What is the key stimulatory hormone of the MMC?
motilin
What drug stimulates motilin receptors?
Erythromycin
What is the action of Protein C and Protein S?
Protein C degrades active V and VIII. Protein S helps protein C
What is the only clotting factor not made in the liver?
Factor VIII (made by reticuloendothelial system)
What is the difference between the three types of Von Willebrand’s Disease?
Type I and III have low amounts of vWF, respond to ddAVP Type II is qualitatively poor vWF
What is the only inherited coagulopathy with long bleeding time?
Von Willebrand’s Disease (autosomal dominant)
What is the pathophysiology of Glanzman’s thombasthenia?
IIb/IIIa receptor deficiency of platelets. Decreased platelet aggregation. Fibrin normally links Gp IIb/IIIa receptors
What is the pathophysiology of Bernard Soulier syndrome?
Ib receptor deficiency of platelets. Decreased adherence of exposed collagen. vWF normally links Gp Ib to collagen
What test confirms the presence of von Willebrand Disease?
Ristocetin test
What are the three possible treatments for vWD?
DDAVP Factor VIII cryoprecipitate
What is the treatment for hemarthrosis in a hemophiliac?
Ice, ROM therapy, Factor replacement Do not aspirate
What are the most common inherited thombophilias?
Factor V Leiden Prothrombin mutation (GP20210) Hyper-homocysteinemia
What is the treatment for overdose of thrombolytics?
Aminocaproic acid (Amikar) - inhibits fibrinolysis
What are the effects of prostacyclin?
Decreased platelet aggregation, vasodilatation, bronchial relaxation
What are the effects of thromboxane?
Increased platelet aggregation, vasoconstriction, bronchial constriction
What stimulates B cells to become plasma cells?
IL-4
Which complements are anaphylatoxins?
C3a, C5a
Which complements make up the membrane attack complex?
C5-9
What cells are responsible for immunosurveillance against CA?
Natural killer cells
What is the source of histamine in blood?
Basophils
What is the source of histamine in tissue?
Mast cells
What is endotoxin? Where does it come from?
Lipopolysaccharide A from gram negative bacteria
What does an elevated mixed venous oxygen saturation (SvO2) indicate?
> 77% - sepsis or cyandide poisoning
What does a low mixed venous oxygen saturation (SvO2) indicate?
<66% - decreased CO
What are the four intraabdominal abscess locations?
sub-diaphragmatic sub-hepatic inter-loop pelvic
What two infections can present within hours post-op?
B-strep Clostridial (GPR)
What is the mechanism of vancomycin? What is the mechanism of it’s resistance?
Inhibits cell wall synthesis Altered cell wall (unable to bind)
What is the mechanism of quinolones?
DNA gyrase inhibition
What is the mechanism of amphotericin
binds sterols to alter fungal cell wall
What antibiotic prolongs neuromuscular blockade?
Clindamycin
What are the risks of a blood transfusion?
CMV is highest Hep C 1:30-150,000 HIV 1:500,000
What are the vitamin K dependent factors?
II, VII, IX, X, protein C + S
Which antibiotics are bacteriocidal, with irreversible binding to 30S ribosome subunit, and resistance due to decreased active transport?
Aminoglycosides (gentamicin, neomycin, tobramycin)
What is the only depolarizing neuromuscular blocker used?
Succinylcholine
What is an adverse effect of succinylcholine in burn patients?
hyperkalemia
What are the effects of reglan (metoclopramide)?
Dopamine receptor blocker - Increases LES tone and gastric motility
What is the mechanism of digoxin?
inhibits Na/K ATPase to increase calcium in heart
What is the effect of digoxin?
Slows AV conduction, inotrope but does not increase O2 consumption
What pressor is most useful in GIB?
Vasopressin: reduces splanchnic blood floow, portal flow ~40%. Give with B-blocker to avoid angina
What gastric contents have the highest concentration of K?
Saliva (20 meq) > gastric (10 meq) > pancreatic/duodenal (5 meq)
What is the water distribution in a average person?
2/3 is intracellular and 1/3 is extracellular (80% of extracellular fluid is interstitial and 20% is plasma)
What drug can reverse adverse effects of steroids on wound healing?
Vitamin A
How many kcal/g are in protein, fat, and carbs?
Protein: 4 kcal/g Fat: 9 kcal/g Carbs: 3.4 kcal/g
Describe vitamin D synthesis
Vit D made in skin, to liver for (25-OH, calcidiol), then to kidney for (1-OH, calcitriol), then active
What is the respiratory quotient?
Ratio of CO2 produced to O2 consumed 0.7 = fat used 1.0 = carb used
What is the preferred fuel of the colon?
Short chain fatty acids - butyric acid
Describe fat digestion
Long chain: Micelles to enterocytes to chylomicrons to lymphatics (to jxn LIJ/SCV); medium and short chain are directly absorbed into portal system with aa’s and carbs
What is the preferred fuel of the small bowel?
Glutamine
What is the #1 amino acid in the blood stream?
Glutamine
What causes a decrease in glutamine in the blood stream during stress?
Glutamine goes to kidney to form ammonium to help acidosis
What vitamin deficiency causes hyperglycemia (relative diabetes) and neuropathy?
Chromium
What vitamin deficiency causes perioral rash, hair loss, poor healing, and change in taste?
Zinc
What vitamin deficiency causes weakness (respiratory) and encephalopathy?
Phosphate (needed for ATP)
What vitamin deficiency causes anemia and neutropenia?
Copper
Describe the Cori cycle
glucose to lactate, to the liver, to glucose
During starvation, what does the brain use for fuel?
ketones from fatty acids (instead of glutamine)
What are the electrolyte concentrations of NS vs LR?
Normal saline: 154 meq Na and Cl LR: Na 130, K 4, Ca 2.7, Cl 109, bicarb 28
What two electrolyte abnormalities cause hyperexcitability (increased reflexes, tetany)?
Hypocalcemia and hypomagnesemia
How does magnesium affect calcium?
Low Mg inhibits PTH, so replace MG if difficulty correcting Ca
What are the phases of the cell cycle?
G1 - most variable period; S - DNA replication; G2; M - Mitosis
What phase of the cell cycle is most sensitive to radiation therapy?
M - mitosis
What are the recommendations for biopsy of an extremity sarcoma?
Excisional if < 4cm, otherwise longitudinal incision (less lymphatic disruption, easier to excise scar if biopsy positive)
What is a complication of bleomycin and busulfan?
pulmonary fibrosis
What are the risks of tamoxifen?
DVT and Endometrial cancer
Ret proto-oncogene is diagnostic for what? What is the treatment?
Medullary thyroid cancer Patient with family history of MEN who has ret proto-oncogene should have total thyroidectomy
What is a side effect of vincristine and cisplatin?
Neurotoxicity
What cells provide wound contraction?
Myofibroblasts
What cells are responsible for healing by secondary intention?
Myofibroblasts
What is the principal collagen late in scar?
Type I
What is the principal collagen in a healing wound?
III (this is the collagen of granulation tissue)
What type of collage is low in Ehler-Danlos?
III
What is the time frame of collagen production in a wound?
Begins day 3, max at day 21, then constant amount but more crosslinking, strength
What is the order of cells to a healing wound?
Platelets PMNs macrophages (essential) fibroblasts (dominant by day 5)
What are the effects of TGF-B?
stimulates fibroblasts and chemotactic for neutrophils (too much/too long can cause fibrosis)
What is the effect of PDGF?
Attracts fibroblasts and increases smooth muscle to speed matrix deposition and collagen formation
What is the main source of TNF?
Macrophage/monocyte
What cell does TNF recruit and activate?
neutrophils
How does TNF cause wasting/cachexia in cancer patients?
Anorexia, glycolysis, and lipolysis
What is batson’s plexus, and what is it’s significance?
Valveless vertebral veins that connect to internal vertebral venous plexus They allow direct mets to the spine
What is Poland’s syndrome?
Amastia, hypoplastic shoulder, no pectoralis
What is Mondor’s disease? What is the treatment?
thrombophlebitis of superficial vein of breast. Cord like mass laterally. Treat with NSAIDS
Describe the “T” staging of breast cancer
T1 = 5cm T4 = skin or chest wall involvement
Describe the “N” staging of breast cancer
N1 = ipsilateral lymph nodes (1-3 LN on path) N2 = fixed or matted LN (4-9 LN on path) N3 = infraclavicular, supraclavicular, or internal mammary (>10 LN on path)
Describe the staging of breast cancer according to TNM guidelines
Stage I = T1 Stage IIA = T1N1 or T2N0; IIB = T2N1, T3N0 Stage IIIA = T1-3 and N2, or T3N1; IIIB = T4N0-2; IIIC = Any T N3
How does hormone receptor status in breast cancer affect prognosis?
ER+PR+ > ER-PR+ > ER+PR- > ER-PR-
What % of DCIS develop invasive cancer?
50%
What % of LCIS develop invasive cancer?
30-40% (in either breast)
What is the difference pathophysiologically in cancer risk between DCIS and LCIS?
DCIS is a precursor to cancer LCIS is a marker of risk
What % of Phyllodes tumor are malignant?
10%
What is the treatment for Phyllodes tumor?
Wide local excision, rarely mastectomy. No axillary node dissection necessary (spread is hematogenous, not lymphatic)
What type of cancer is BRCA1 and BRCA2 associated with?
BRCA1 - ovarian CA (50%) BRCA2 - male breast CA
What are the indication for RT after mastectomy?
> 4 nodes skin or chest wall involvement +margins
What are absolute contraindications to breast-conserving therapy requiring radiation?
Prior radiation to breast/chest wall Radiation therapy during pregnancy Diffuse suspicious or malignant appearing microcalcifications Widespread disease not able to be incorporated by local excision Positive margins
What is the #1 cause of blood nipple discharge?
Intraductal papilloma - no risk of CA
What is Stewart-Treves syndrome?
Angiosarcoma arising from chronic lymphadema, often as a complication after mastectomy. Presents as a purplish mass on arm ~10 yrs s/p MRM
What is the difference between the two types of alveoli?
Type I: functional gas exchange Type II: produce surfactant (1% of alveoli)
What is the association between the thymus and myasthenia gravis?
10% of m.g. have thymomas Resecting thymus (even if no thymoma) in m.g. improves 90%
Popcorn lesion on CXR
hamartoma
What are the indications for CABG?
intractable symptoms >50% left main triple vessel disease 70% LAD + 1 other vessel
What is the treatment for a patent ductus arteriosus
Indomethacin - blocks PG production - effective in ~70% Surgery for those that don’t close at 6 months of age
What are the effects of IABP?
Augments diastolic coronary blood flow and reduces afterload by inflating during diastole (inflates 40msec before T wave, deflates with p wave)
What electrolytes are actively secreted by the colon?
K and HCO3
Describe the blood supply of the rectum
Superior rectal artery off IMA Middle off internal iliac Inferior off internal pudendal (off internal iliac)
What are the most common genetic mutations in colon cancer?
p53 (85%), DCC (70%), ras (50%)
Amsterdam criteria
3 1st generation relatives, over 2 generations, 1 diagnosed before age 50
Gardner’s syndrome
colon CA and desmoid tumors
Turcot’s syndrome
colon CA and brain tumors
Peutz Jeghers
polyposis and mucocutaneous pigmentation; increased risk of GI, gonadal, breast cancers
What gene is associated with sacroiliitis in IBD?
HLA B27
Where are most anal fissures located?
posterior midline, 10% are anterior in women
What are the causes of anal fissures which are lateral or recurrent?
IBD, TB, or syphilis
What is normal LES tone and length?
15-25 mm Hg, 4cm long, 40cm from incisors
What is the treatment of diffuse esophageal spasm?
calcium channel blockers
What is the pathophysiology of achalasia?
Decreased ganglion cells in Auerbach’s plexus, absence of peristalsis and esophageal dilation. High LES pressures
What is main arterial supply to stomach when used to replace esophagus?
right gastroepiploic artery
What is the treatment of esophageal leiomyoma?
If symptomatic or >5cm excise by enucleation via thoracotomy (R if middle, L if lower esophagus) Do not biopsy on EGD
What is Killian’s triangle?
A potentially weak spot where a pharyngoesophageal diverticulum (Zenker’s) is more likely to occur. Posterior triangular area in the pharynx between the inferior constrictor and the cricopharyngeus muscle
What is a painless mass on the roof of the mouth?
Torus - bony exotosis, midline of palate
Which has a greater risk for cancer, leukoplakia or erythroplakia?
Erythroplakia
What is the general treatment for different stages of head and neck SCCa?
Stage I+II(up to 4cm, no nodes) Rx with single modality (surgery or RT) Stage III+IV get combined modality
What is the treatment for glottic Ca?
If cords not fixed, then RT If cords fixed, need surgery and RT
What is the most common type of lip cancer?
Epidermoid carcinoma. Lower > upper due to sun exposure
What is the usually presentation of nasopharyngeal carcinoma?
50% presesnt late (as neck mass). Drain to posterior neck nodes. A/w EBV
What is the treatment of lip cancer?
Resect, primary closure if <1/2 of lip, otherwise flaps. Radical neck dissection if node+
What is Plummer-Vinson syndrome? What type of cancer is increased?
Triad of dysphagia (due to esophageal webs), glossitis, and iron deficiency anemia. Increased risk of esophageal/tongue Ca
What are the most common malignant salivary gland tumors?
1 - Mucoepidermoid carcinoma #2 - Adenoid cystic carcinoma (#1 of submandibular and minor glands)
What are the most common benign salivary gland tumors?
Pleomorphic adenoma (#1 overall), Warthin tumor
What is the treatment for a benign salivary gland tumor?
Superficial parotidectomy (spare CNVII). If malignant, take whole parotid. If high grade, need radical neck dissection
What is the difference between a radical neck dissection and a modified radical neck dissection?
Radical neck takes CN XI, SCM, IJ. Modified spares some combination of those structures (CN XI is most morbid)
What is the cause of unilateral nasal obstruction and recurrent epistaxis in a teen male? What is the treatment?
Juvenile Nasopharyngeal Angiofibroma - benign but locally agressive vascular tumor of nasal cavity. Embolize (internal maxillary artery), then extirpate
What is a replaced right or left hepatic artery?
Replaced right - originating off SMA (occurs in 17%) Replaced left - originating off left gastric (occurs in 10%)
What are Kupffer cells?
Specialized macrophages in the liver responsible for clearing portal blood and immunosurveillance. Also responsible for early alcohol-induced liver injury.
Describe the anatomical relationship of the Portal triad
Portal vein posterior to CBD (on R) and hepatic artery (on L)
What is the #1 cause of benign biliary stricture?
Iatrogenic (lap chole)
What are the symptoms and treatment of cholangitis?
Fever, RUQ pain, jaundice, +/- hypotension, MS changes. Needs immediate IV Abx, IVF, emergent decompressions/drainage of CBD
What is the treatment of gallbladder adenocarcinoma?
Cholecystectomy adequate if confined to mucosa. If grossly visible tumor - regional lymphadenectomy, wedge segment V, skeletonize portal triad
What is the triad of hemobilia?
UGIB, RUQ pain, and jaundice - caused by fistula between biliary duct and hepatic arterial system
What is the treatment of hemobilia?
workup and treatment with arteriogram
How does the gallbladder concentrate bile?
Active absorption of Na, Cl (H20 then follows)
What is the treatment for hepatic adenoma?
Hepatic adenoma is an indication for resection 10% rupture/bleed + malignant potential
What is the treatment for hepatic hemangioma?
Do nothing unless giant or symptomatic/consumptive
What is Kasabach-Merritt syndrome?
Consumptive coagulopathy or CHF due to hemangioma - usually in infants.
What is the treatment of liver amebic abscess?
metronidazole, not surgical
What is the treatment of hydatid cysts?
Surgical resection with chemotherapy before and after (albendazole or mebendazole)
What is the work-up of hydatid cysts?
Casoni skin test + Indirect hemagglutination
What are the main risk factors for hepatocellular carcinoma?
Alcoholism, Hep B+C, hemochromatosis, PBC, aflatoxin, alpha-1-antitrypsin deficiency - PBC and Wilson’s are not risk factors
What type of HCC has best prognosis?
Fibrolamellar
What is the difference between these types of peripheral nerve injuries: neuropraxis, axonotmesis, neurotmesis?
Neuropraxis - focal demyelination, improves Axonotmesis - loss of axon continuity (nerve and sheath intact). Regen 1mm/day Neurotmesis - loss of nerve continuity, surgery required for nerve recovery
What triggers ADH release?
Produced when high osmolarity is sensed at supraoptic nucleus of hypothalamus
What is Diabetes Insipidus?
Alcohol and head injury inhibit ADH release - high UOP, low urine SG, high serum osmolarity/Na
What is SIADH?
Increased ADH release most often by head trauma/tumors or SCLC. Oliguria, high urine osmolarity, low serum osmolarity/Na
What is the effect of ADH?
Causes increased free water absorption at the distal tubules and collecting ducts and increases peripheral vascular resistance
What is cerebral perfusion pressure?
Mean Arterial Pressure (MAP) - Intracranial Pressure (ICP) Keep ~70
What is Cushing’s triad?
Hypertension, bradycardia, and Kussmaul respirations (slow, irregular) associated with increased ICP
Describe the Glasgow Coma Scale ratings
Motor: 6 commands, 5 localizes, 4 withdraw pain, 3 flexion, 2 extension, 1 none Verbal: 5 oriented, 4 confused, 3 inappropriate, 2 incomprehensible, 1 none Eyes: 4 spont, 3 command, 2 pain, 1 none
What are the signs of spinal shock?
Hypotension with bradycardia, warm perfused extremities (vasodilation) Cord injury above T5
What are the deficits in anterior spinal artery syndrome?
Lose bilateral motor, pain, and temperature. Keep position sense, light touch
What is Brown-Sequard syndrome?
Spinal cord hemi-transection Lose ipsilateral motor, contralateral pain and temperature
What is Central Cord Syndrome?
Acute cervical spinal cord injury characterized by bilateral loss of upper extremity motor, pain, and temperature; legs relatively spared. Often due to hyperextension