Medicine Flashcards
What are the main goals of anesthesia management in patients with AKI? 2
(1) maintenance of an adequate systemic blood pressure and cardiac output
(2) avoidance of further renal insults, including hypovolemia, hypoxia, and exposure to nephrotoxins.
Invasive hemo-dynamic monitoring is mandatory.
What does AKIN classify and how is it different than RIFLE?
Acute Kidney Injury Network
Acute rise in serum creatinine within 48hrs
- Stage 1= same as Risk +increase in SCr ≥ 0.3 mg/dL (≥ 26.4 μmol/L)
- UO < 0.5 mL/kg per hour × 6 h
- Stage 2= same as Injury
- UO < 0.5 mL/kg per hour × 12 h
- Stage 3= same as Failure + initiation of renal replacement therapy
- UO < 0.3 mL/kg per hour × 24 h or anuria × 12 h
UO=same criteria as in RIFLE
K sparing diuretics
Amiloride and Triamterene - directly inhibit epithelial Na channel.
Spironolactone - competes with Aldosterone for binding to mineralocorticoid receptor.
What are the three layers of the nerve?
Epineurium: outermost layer, surrounds peripheral bundles and blood vessels.
- Vasa nervorum
- Protects against compressive and stretching forces.
Perineurium: surrounds groups of fascicles.
- Provides structural support and acts as a diffusion barrier.
Endoneurium: surrounds individual nerve fibers and Schwann cells.
Sunderland Nerve Injury Classification-5
- 1st degree=to endoneurium (rapid recovery w/in days to months)
- 2nd=through endo
- 3rd=to perineurium
- 4th=through peri
- 5th=through epineurium
injury from inside out
At what temperature should a postop fever be worked up?
1st day if greater than 101.6F after administration of Acetaminophen
OR
greater than 101.6F any day after
3 causes of acute kidney injury? 3
- Prerenal
- Renal
- post renal
Classified using urinary indices
Timing of postop fever is classified in what 4 categories?
- immediate
- acute(24-72hours postoperatively)
- subacute(within the first week)
- delayed.
AHI
Apnea hypopnea index (AHI): Apneas and hypopneas per hour
Apnea: Breathing interruption > 10 seconds • Hypopnea: More than 50% decrease in nasal airflow or more than 2/3 decrease in tidal volume with 3% decrease in oxygen saturation
What is Uremic Syndrome and what is it a complication of?
complication Chronic Kidney Disease
signs and symptoms (anorexia, nausea, vomiting, pruritus, anemia, fatigue, coagulopathy) that reflect the kidney’s progressive inability to perform its excretory, secretory, and regulatory functions.
- BUN conc is a useful indicator of severity and treatment response
Stoelting p.434
5-HT3 Antagonist
Zofran/Ondansetron Pharm category: Anti-emetic MOA: selective 5-HT3 receptor antagonist that blocks serotonin both peripherally on CN 10 terminals and centrally in CTZ Caution: psych pts/pts on SSRIs (risk of serotonin syndrome), prolonged QT syndrome pts (can develop torsades de pointes) Other ‘setrons’ all equally effective
3 levels for neurosensory test results and how are they tested?
Level A: 2pt discrimination and brush stroke, closest distance pt can tell there are two points- boley gauage, greater than 2mm=abnorm – norm= 1st deg
Level B: Contact detection, Semmes Weinstein monofilaments, narrowest diameter filament that requires the least amount of force to detect. -norm=2nd degree, mod impaired
Level C: Pain sensitivity, norm= 3rd deg, mod impairmenmt; abnorm=4th deg, severely impaired
Celecoxib (Celebrex)
selective COX-2 inhibitor, no GI effects
INC CV effects due to imbalance between Prostacyclin (COX2) and Thromboxane (COX1)
-TXA2 is produced primarily by COX-1 activity of platelets, and produces vasoconstriction and enhanced platelet aggregation
H1 Antagonist
Phenergan/Promethazine Pharm category: Anti-emetic, H1 antagonist 1st gen (crosses BBB:sedative) MOA: antagonist at D2, H1 (and even M1 sites) Caution: extrapyramidal symptoms (via D2 blockade), tissue injury/irritation. Caustic. Thrombophlebitis.
What fibers does each level of neurosensory tests test for?
Level A: large myelinated fibers (last to regain fxn in recovery phase)
- 2pt discrimination- A alpha
- Brush stroke- A alpha and A beta, slowly adapting large myelinated axons.
Level B: quickly adapting large myelinated fibers, A alpha
- Contact detection
Level C: small myelinated A delta and non myelinated C fibers (most resistant to injury)
- Pain sensitivity
Warm= A delta
Cold= C fibers
What does RIFLE stand for?
acute rise in serum creatinine over 7 days
R- risk of renal failure
I- injury to kidney
F- failure of kidney fxn
L- loss of kidney fxn
E- end stage renal failure
Definition of fever?
resetting of the hypothalamic center at a higher level in response to pyrogens (fever causing substances)-t umor necrosis factor, IL1b, IL6
-sign of inflammarion
One liner for pulmonary embolism
occlusion of ≥ 1 pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis.
Risk of embolization is higher with thrombi proximal to the calf veins.
How is AKI diagnosed?
- Serum Creatinine
- Urine Output
- increase in serum creatinine by 0.3mg/dL in 48hrs or by greater than 50% w/in 7days
- dec in urine output to less than 0.5 mL/kg/hr
- norm= ~1mL/kg/hr
Treatment for hiccups?
Tx with Chlorpromazine (D2 ANTagonist) 25-50mg IM/IV or 25mg PO tid for 1-2 days. Or Baclofen 5mg tid or Gabapentin 200mg tid. Benzonatate: antitussive. Ester local anaesthetic derived from tetracaine. Anaesthetizes vagal afferent fibers. 100mg PO Q4H up to 600mg per day.
Toradol oral/ Ketorolac IV
Toradol recommended for up to 5 days after use of Ketorolac IV for mod severe acute pain.
A1 receptors
smooth muscle contraction
A1-blood vessels in GI, kidneys,
ureter, vas deferens
What 3 nondepolarizing muscle relaxants are not dependent on renal clearance? Which 2 form an active metabolite that may accumulate?
- Mivacurium
- Atracurium
- Cisatracurium
Laudanosine- active metabolite formed by Atracurium and Cisatracurium
- @ high plasma conc can stimulate CNS
**DEC inital dose and admin subsequent doses by monioring w/ peripheral nerve stimulator.
Hypopnea
More than 50% decrease in nasal airflow or more than 2/3 decrease in tidal volume with 3% decrease in oxygen saturation
Obstructive Sleep Apnea dx
Criteria for OSAS diagnosis
Five or more obstructive events per hour of sleep AND presence of symptoms
OR
Fifteen or more obstructive events per hour of sleep, irrespective of symptoms
What happens leading up to emesis?
Leading up to emesis, antiperistalsis takes place where contents from ileum can migrate upward to the duodenum and stomach lower esophageal sphincter relaxes and vomitus moves to esophagus
Diagnosis of Rheumatoid Arthritis
Based on clinical, physical, and radiographic findings:
• Laboratory findings
–Positive rheumatoid factor (RF), antinuclear antibodies (ANA), human leukocyte antigens (HLA) Dw5 and DRw
–Elevated erythrocyte sedimentation rate
–Decrease in serum albumin
–Synovial aspirate: Cloudy, reduced viscosity, white cell blood count > 20,000
Greenbook p.341
D2 Antagonist
Reglan/metoclopramide D2 Receptor Antagonist (also 5-HT4 agonist, 5-HT3 antagonist) Pharm category: antiemetic, prokinetic MOA: blocks D2 receptor in CTZ; enhances response to Ach of tissue in upper GI tract causing enhanced motility and accelerated gastric emptying Caution: extrapyramidal symptoms; tardive dyskinesia (stiff jerky movements), akathisia (muscle quivering/restlessness). If need to treat this, give Benadryl
NK1 Antagonist
Emend/Aprepitant Pharm category: anti-emetic, substance P/Neurokinin 1 receptor antagonist MOA:prevents acute/delayed vomiting via inhibition of substance P/NK1 receptor; also augments antiemetic activity of 5-HT3 receptor antagonists and corticosteroids to inhibit acute and delayed phases of chemotherapy-induced emesis MOST EFFECTIVE PREOP
Virchows triad
Virchow’s Triad (stasis, injury, thrombophilia)
- Conditions that impair venous return (bed rest and confinement without walking)
- Conditions that cause endothelial injury or dysfunction
- Underlying hypercoagulable (thrombophilic) disorders
= risk factors for PE
Severity Index of OSA
AHI:
- MILD: 5-15
- MOD: 15-30
- SEVERE: >30
RDI:
- MILD: 10-30
- MOD: 30-50
- SEVERE: >50
Criteria for identifying prerenal azotemia causes
- Urinary sodium concentration (mEq/L) = >20
- Urine osmolality (mOsm/kg) = >500
- Fractional excretion of sodium (%) = <1
- Fractional excretion of urea (%) ratio of urine to plasma creatinine concentration = > 40
- ratio of urine to plasma osmolarity = >I.5
- sediment = Normal
Main receptors for Chemoreceptor Trigger Zone? 5
5-HT3 (Hydroxytryptamine) Serotonin - Zofran D2 Dopamine - Reglan/metoclopramide H1 Histamine - Phenergan/Promethazine M1 Muscarinic - Scopolamine NK1 Neurokinin - Emend/Aprepitant
What type of nerve injury causes the different levels of classification?
neuropraxia= first degree block- conduction block, resulting from mild nerve manipulation, traction or compression
Classification correlate histo changes of nerve injury w/ expected clinical outcomes
Axonotmesis- difference in degree of axonal damage
- 2nd –traction/compression resulting in ischemia, edema, or demyelination –thru endoneurium
- 3rd – peritneurium intact- recovery variable, may take months and be incomplete
- 4th –epineurium intact, near complete transection injury- spont recovery unlikely, min improvement may occur in 6-12 months
Neurotmesis- complete transection, traverses entire fascile, loss of epineurium
Regurgitation
effortless passage of gastric contents into the mouth
How is the House-Brackmann score calculated and what do the measurements mean?
measurement is determined by measuring the upwards (superior) movement of the mid-portion of the top of the eyebrow, and the outwards (lateral) movement of the angle of the mouth.
1pt=0.25cm of movement to max 1cm
add for a max of 8pts
1=normal 8/8
2=slight 7/8
3=moderate 5-6/8
4=moderately severe 3-4/8
5=severe 1-2/8
How is septic shock defined?
- systolic arterial blood pressure remains < 90 mmHg or
- shows a reduction of > 40 mmHg from baseline, despite adequate volume resuscitation, in the absence of other causes for hypotension
M1 Antagonist
Scopolamine Pharm category: Anti-cholinergic MOA: blocks action of AcH at parasympathetic sites in smooth muscle, secretory glands and CNS; increases CO via blockade of M1 receptor at cardiac SA-node & is parasympatholytic Caution: anticholinergic toxicity (Hot as a hare: incr body temp, blind as a bat: mydriasis/dilated pupils,dry as a bone: drymouth/eyes/decr sweat, red as a beet: flushed face, mad as a hatter: delirium)
Fujita Classifications
Classification of anatomical sites of obstruction in the upper airway
–Type I: Narrow oropharynx (retropalatal); large tonsils, uvula, and pillar webbing
–Type II: Oral and hypopharyngeal obstruction (retropalatal and retrolingual); low arched palate and large tongue
–Type III: Hypopharyngeal obstruction (retrolingual only); retrognathia, floppy epiglottis, enlarged lingual tonsils
- Most OSA patients have combined problems
- 20% have discrete type II–related OSA
- 10% have discrete type I–related OSA
A2 receptors
A2- inhibits release of NE via neg feedback, peripheral vasocon
Highest risk factors for PONV?
female, non-smokers, anxiety, prior hx of PONV, motion sickness and migraines.
Sunderland versus Seddon Classification
neurapraxia= 1st degree
Classification correlate histo changes of nerve injury w/ expected clinical outcomes
axonotemesis=2-4 degree
neurotemesis= 5th degree
Well’s criteria for PE
stratifies patients for probability of pulmonary embolism
Clinical signs and symptoms of DVT+3
PE is #1 diagnosis OR equally likely+3
Heart rate > 100+1.5
Immobilization at least 3 days OR surgery in the previous 4 weeks+1.5
Previous, objectively diagnosed PE or DVT+1.5
Hemoptysis+1
Malignancy w/ treatment within 6 months or palliative+1
greater than 4=PE likely
B2 receptors
smooth muscle relaxation–> bronchodil, venous dilation
RAAS- Renin Angiotensin-Aldosterone System
activated when there is a drop in blood volume or blood pressure
- drop in blood pressure is interpreted by baroreceptors in the carotid sinus
- Prorenin in blood gets activated to renin by juxtaglomerular cells in kidneys
- Renin converts Angiotensinogen prod by liver to angio 1
- ACE from lung endothelial cells converts angio 1 to angio 2
- angio 2 works on EFFerent arterioles
Bowstring test
movement of medial tendon when tugging on the lateral canthal tendon
Fishbone renal fxn panel, BMP
Evaluate for kidney dysfunction in patients with known risk factors (eg, hypertension, diabetes, obesity, family history of kidney disease).
up top- Na, Cl, BUN; middle right GLU
lower- K, CO2, Creatnine
B1 receptors
B1 heart muscle contraction-increase cardiac output by increasing
heart rate (positive chronotropic effect),
conduction velocity (positive dromotropic
effect), stroke volume (by enhancing
contractility – positive inotropic effect), and
rate of relaxation of the myocardium, by
increasing calcium ion sequestration rate
(positive lusitropic effect), which aids in
increasing heart rate
Emesis
Vomiting- actual oral expulsion of gastrointestinal contents, the result of contractions of the gut and the thoracoabdominal wall musculature. This contrasts with regurgitation, which is the effortless passage of gastric contents into the mouth
Clinical definition for Acute Respiratory Distress Syndrome (ARDS)? 3
- acute onset of bilateral pulmonary infiltrates
- a ratio of arterial partial pressure of oxygen (PaO2) to fraction of inspired oxygen (FiO2) of ≤ 200 mmHg and
- pulmonary artery occlusion pressure ≤ 18 mmHg or no evidence of left atrial hypertension
What are hiccups?
Singultus sudden contraction of the diaphragm and intercostal muscles followed by laryngeal closure. Occur during inspiration. Elevated PaCO2 inhibits Hiccups. Can be precipitated from swallowing blood/debris.
Classes of diuretics and where they work
Loop (Ascending loop of henle): inhibit Na-K-2Cl contransporter
Furosemide
Thiazides (Distal): inhibit Na-Cl cotransporters
Hydrochlorothiazide
K Sparing (Cortical Collecting Duct):
Amiloride
Triamterene
Spironolactone
Eplerenone
Where is vomiting center located? What happens when it is activated?
medulla oblongata and comprises the reticular formation and the nucleus of the tractus solitarius. efferent pathways travel within the 5th, 7th, 9th, 10th, and 12th cranial nerves to the upper gastrointestinal tract, within vagal and sympathetic nerves to the lower tract, and within spinal nerves to the diaphragm and abdominal muscles.
What does fractional excretion of sodium evaluate?
FeNa (%) = [(pCr × UNa)/(pNa × UCr)] × 100
=Filtered sodium/ GFR
helps differentiate between prerenal and renal azotemia
higher than 2% (or urinary sodium concentration > 40 mEq/L) reflects decreased ability of the renal tubules to conserve sodium and is consistent with tubular dysfunction
What are the stages of chronic kidney disease and GFR values? 5
- kidney damage w/ normal kidney fxn- GFR 90+
- kidney damage w/ mild fxn loss- 89-60
3a. mild to mod loss of fxn- 59-44
3b. mod to severe- 44-30 - severe loss of fxn- 29-15
- kidney failure- less than 15
Rheumatid Arthritis VS Osteo
RA- autoimmune, symmetric multi jt involvement, pain greater than 1 hr in the morn and improves throughout the day, 50% TMJ involvement
