Comp Exam Practicum IV Flashcards
What is the most common congenital defect in children?
VSD
Left to right shunt
-increased pulmonary blood flow
-Acyanosis
-ASD
-VSD
-PDA
-Aortopulmonary window
right to left shunt
-decreased pulmonary blood flow with cyanosis
-Tetralogy of Fallot (VSD, overriding aorta, right ventricular outflow tract obstruction, right ventricular hypertrophy
-pulmonary atresia
-tricuspid atresia
-ebstein anomaly
Complex shunts
mixing of pulmonary and systemic blood flow with cyanosis
-transposition of the great arteries
-truncus arteriosus
-total anomalous pulmonary venous connection
double outlet right ventricle
hypoplastic left heart syndrome
What is a diaphragmatic hernia? is it an emergency?
-surgical emergency
-abdominal contents in chest wall compressing lung, if lung cannot grow it will never grow
-herniation of abdominal contents into thorax at 8 weeks gestation with resultant ipsilateral lung hypoplasia
What side is most commonly affected with diaphragmatic hernia?
-In 80% to 90% of diaphragmatic defects, a portion of the posterior diaphragm fails to close, (80%–85% of cases on the left side), forming a triangular defect known as the foramen of Bochdalek.
i. Hernias through the Foramen of Bochdalek that occur early in fetal life usually cause respiratory failure immediately after birth d/t pulmonary hypoplasia
What is pulmonary hypoplasia?
normal ratio of airways and alveoli but a decrease in number which results in a decreased total lung mass
pulmonary vascular abnormalities
decrease in pulmonary artery size, decreased branching, muscular hypertrophy of the media and smooth muscle in small diameter vessels
persistent pulmonary HTN
elevated PVR resulting from pulmonary hypoplasia and vascular abnormalities (irreversible) and constriction of normal vessels (reversible)
Dx of diaphragmatic hernia
-prenatal U/S
-30% of cases are associated with Polyhydramnios
Diaphragmatic hernia is more common in__________..
males over females
-high incidence of other chromosomal abnormalities and other genetically determined disorders
CV anomalies associated with CDH
-ASD
-VSD
-PDA
-TOF (15%)
CNS anomalies associated with CDH
-hydrocephalus
-myelomeningocele
GI anomalies associated with CDH
-duodenal bands
-malrotation of gut (40%
GU anomalies associated with CDH
hypospadias
Tracheoesophageal fistula
-connection from stomach to trachea (blind pouch)
Prenatal dx of TEF
-polyhydramnios and U/s (44%) predictive
Which congenital heart defects are associated with TEF?
VSD=most common
also:
-PDA
-TOF
-ASD
-AV canal
-coarcation of aorta and right sided aortic arch
How to affected neonates present with TEF?
spillover of pooled oral secretions from the pouch and may develop progressive gastric distension and tracheal aspiration of acidic gastric contents via the fistula
what do you want to avoid in TEF?
-mask ventilation and tracheal intubation? because they may exacerbate gastric distension and further compromise respirations
-avoid feeding
Is TEF an emegency?
urgent although not emergent (unless respiratory insufficiency)
Where do you want ETT in TEF?
past level of lesion but above carina
What kind of pulse ox is indicated in TEF?
preductal: r hand
post ductal: L hand or foot
Surgical techniques TEF
-right thoracotomy or thorascopy using postero-lateral extrapleural approach
-one lung ventilation
-fistula ligated and esophagus primarily anastamosed
-precordial stethoscope placed left exilla
Post op concerns with TEF
-tracheomalacia (as high as 75%)
-RLN injury
-vocal cord paresis
Which congenital defects is TEF associated with?
VATER/VACTERAL
Vertebral defects
Anal atresia/imperforate anaus
Cardiac defects
TEF
Esophageal fistula/atresia
Renal defects/radial abnormalities
L radial limb aplasia
Who is most commonly affected with pyloric stenosis?
first born males 2nd -6th week of life
What is pyloric stenosis?
-hypertrophy of the muscle (muscularis) of the pyloric sphincter which causes obstruction and persistent vomiting
Is pyloric stenosis an emergency?
MEDICAL emergency not surgical emergency; electrolytes must be normalized prior to surgery
-surgical correction involves pyloromyotomy to relieve structure
Clinical presentation of pyloric stenosis
-hypochloremia
-hypokalemia
-metabloic alkalosis
-dehyration
Preoperative requirements of pyloric stenosis
-hydration normal
-UOP assessed
Biochemistry:
PH 7.3-7.5
NA>132
Cl>90
K>3.2
Bicarb <30mmol/L
Considerations for induction and emergence with pyloric stenosis
induction: awake and RSI
Emergency: extubate only when fully awake with intact protective airway reflexes
cautious with opioids
Gastroschisis
-herniation of abdominal contents from a defect lateral to the umbilicus (usually right sided)
-covering sac absent
-bowel wall may be thickened with fibrin peel due to exposure to amniotic fluid
-may involve stomach bladder, uterus, rarely liver
-maternal age <20 years
Omphalocele (Exomphalos)
-maternal age >40 years
-herniation of abdominal contents through extra embryonal part of the umbilical cord
-covering sac is present
-may be minor herniation into umbilical cord, a small 5-8cm defect or a large defect including liver with poorly developed abdominal and thoracic cavities and pulmonary hypoplasia
Where is the larynx in a full term infant located?
C4
Epiglottis infant
-omega shaped
-angled away from axis of trachea (floppy)
Larynx position in premature neonates
C3
LMA up to 5kg
1
LMA 5-10kg
1.5
LMA 10-20kg
2
LMA 20-30kg
2.5
LMA 30-50
3
LMA 50-70kg
4
LMA 70-100
5
ETT 1000g premature
2.5
ETT premature 1000-2500g
3.0
Neonate-6 month ETT
3-3.5
6 month to 1 year ETT
3.5-4.0
1-2 year ETT
4.0-5.0
> 2 years ETT
(age in years +16/4) (uncuffed)
Cuffed=(age in years/4)+3
Peds Sux dose
IV 1-2mg/kg
IM 4-5mg/kg
preceded with atropine 0.01-0.02mg/kg
which condition is unaffected by increased serum K associated with sux?
cerebral palsy=no impact on serum K
normal aortic valve
2.5-3.5cm2
mild s/s of aortic stenosis size
0.7-0.9
severe/critical aortic stenosis size
0.5-0.7
symptoms of aortic stenosis
-DOE
-angina
-orthostatic syncope
‘SAD’
Anesthetic goals of aortic stenosis
-maintain HR 50-70
-maintain contractility
-maintain preload (avoid NTG and NTP)
-opioids over agents
-avoid hypotension
full, slow, and constricted
what will you see with aortic stenosis on PCWP
prominent V and A waves
What will you see in aortic stenosis on arterial waveform?
-absent dicrotic notch and slower anacrotic notch
-pulsus tardus (slower upstroke), delayed peak, narrow PP
Pressure volume loop aortic stenosis
taller and shifted R
90% of aortic stenosis develop___________.
von willebrand
causes of aortic stenosis
-bicuspid aortic (most common)
-rheumatic fever
-infective endocarditis
Atrial kick provides _____% CO.
20-30%
does not change with stiff ventricle
At rest, coronary blood flow =
225ml/min (4-5% CO)
Coronary perfusion autoregulated between MAP______.
60-140mmHg
-autoregulation responds to local metabolism, myogenic response and autonomic NS
-local metabolism is most important determinant of coronary vessel diameter
At rest the myocardium consumes O2 at a rate of_____.
8-10ml/min/100g with extraction ratio of 70%
Coronary perfusion pressure calculation
aortic DBP-LVEDP
Coronary blood flow=coronary perfusion pressure/coronary vascular resistance
coronary dilation
-B2
-histamine-2
-muscarinic
-adenosine
coronary constriction
-alpha 1
-hypocapnia
-histamine 1
What determines CPP?
diastolic BP
LaPlace Law of heart
Pressure x radius/2 x wall thickness
Primary target of heart failure therapy
reduce LV wall stress
What are the 2 most common surgeries that trigger the baroreceptor reflex
-carotid endarterectomy
-mediastinoscopy
Where are peripheral baroreceptors located?
bifurcation of the common carotid arteries and aortic arch
cardiopulmonary stretch receptors are located where?
-atria
-LV
-pulmonary circulation
Baroreceptor reflex
attempts to preserve CO during acute blood loss and shock
-critical for maintaining BP when changing from supine to standing position
Bainbridge reflex
-tachycardia caused by increase venous return
counterbalanec to baroreceptor
-low pressure cardiopulmonary baroreceptor reflex
Bezold Jarisch
-empty heart–> decreased HR and decreased BP
Triad of Bezold JArisch
-bradycardia
-hypotension
-coronary artery dilatation
Inferior RCA leads
II
III
aVF
Lateral CxA leads
I
aVL
V5
V6
Septum LAD leads
V1
V2
Anterior LAD
V3
V4
Initial dose of cardioplegic solution
may be hypothermia or start warm and progress to cold
Antegrade cardioplegic solutions administered
through catheter placed in proximal aorta between aortic clamp and aortic valve
retrograde cardioplegic solution placed
through right atrium into coronary sinus
coronary steal
reduction in perfusion of ischemic myocardium with simultaneous improvement of blood flow to nonischemic tissue
-sodium NTP
-dipyridamole
-adenosine
-nitroglycerin
-isoflurane
A wave of CVP
right atrial contraction
just after P wave (atrial depolarization)
C wave of CVP
right ventricular contraction
-bulging of triscuspid valve into RA
-just after QRS complex (ventricular depolarization)
X descent of CVP
RA relaxation
-ST segment
V wave
passive filling of RA
Just after T wave begins (ventricular repolarization)
Y descent
-RA empties through open tricuspid valve
After T wave ends
DISS
-prevents inadvertent misconnections of gas hoses
-each gas hose and connector sized and threaded for each gas
-pressure change that occurs (pipeline pressure is about the same as intermediate system)
PISS
prevents inadvertent misconnections of gas cylinders
-pin configuration on each hanger yoke assembly different for each gas making unintended connection of wrong gas unlikely
Oxygen PISS
2,5
Nitrous oxide PISS
3,5
Air PISS
1,5
Nitrogen PISS
1,4
Oxygen tank capacity and pressure
625-660L
1900-2000psi
nitrous tank capacity and pressure
1590L
745psi
air tank capacity and pressure
625L
1900psi
low pressure leak test
-assesses integrity of low pressure circuit from flowmeter valve to common gas outlet
-attach bulb to CGO and create negative pressure (~65cm H20)
-if there is minimum FGF when machine is turned on then machine must be turned off
-ventilator should be off
-vaporizers should be off at first but then test repeated with each vaporized turned on
Phase 1capnography
inspiration ends
Phase II capnography
expiration of CO2 from deadspace and upper alveoli
PHase III capnography
expiration from lower lung units
Phase IV capnography
inspiration of fresh gas that does not contain CO2 (it should return to zero with each breath)
Phase IV terminal upswing occurs with:
pregnant and obese patients due to:
-decreased lung compliance
-decrease FRC
alpha angle of capnography is increased with
-expiration outflow obstruction (COPD)
-bronchospasm
-kinked ETT
beta angle of capnography increased
rebreathing CO2 from faulty inspiratory valve
Possible causes of rebreathing
-faulty expiratory valve
-inadequate inspiratory flow
-malfunction of CO2 absorber system
-partial rebreathing circuits
-insufficiency expiratory time
-depleted CO2 absorber
2 branches of the superior laryngeal nerve
External branch–cricothyroid membrane
internal branch-sensory above the cords
Recurrent laryngeal nerve provides innervation to
-sensory below cords
-posterior cricoarytenoid m.s.
glossopharyngeal (IX) nerve provides sensory innervation to
vallecula
-base of tongue
peripheral chemo receptors
in carotid and aortic bodies at bifurcation of common carotid artery
-responsible for ventilatory effects
central chemoreceptors
80% of ventilatory response to CO2 that originates in central medullary centers responsible for acid-base regulation and due to thermosensitive receptors in medulla
-sensitive to changes in H ion concentration
components of circle breathing system
(not part of low pressure system)
-fresh gas inflow
-unidirectional valves
-corrugated tubes
-Y-piece
-APL valve
-reservoir bag
-CO2 absorbent
O2 flush valve goes from_______
intermediate pressure system to common gas outlet directly to patient
Where is the oxygen sensor located?
distal to the common gas outlet as proximal to the patient as possible to be able to determine the concentration of oxygen moving towards the patient
Tx of laryngospasm
- removal of offending stimulus
- continuous positive pressure
- deepening of anesthesia
- 20mg IV sux
uterine blood flow increaases from a baseline of _____(prepregnancy) to _______at term.
50ml/min –> 700-900ml/min
-90% perfuses the intervillous space and 10% to myometrium
Uterine vascular resistance
-low-resistance uteroplacental vascular bed and maternal vasodilation due to increased levels of prostacyclin, estrogen, and progesterone
endogenous vasoconstrictors
-cathecholamines (Stress)
-vasopressin (in response to hypovolemia)
exogenous vasoconstrictors
-epinephrine
-vasopressors (phenylephrine>ephedrine)
-local anesthetics (in high concentrations)
acid base changes in pregnancy
-due to increased MV and lower CO2 there is primary respiratory alkalosis of pregnancy. To compensate there is increased renal excretion of bicarb (metabolic aidosis)
normal P50
26.7
fetal P50
17-20
Pregnant ABG
7.4-7.45
pO2=100mmHg
pCO2=27-32mmKG
HCO3=18-21
meralgia paresthetics
exaggerated lumbar lordosis stretches the lateral femoral cutaneous so there is paresthesia over anterolateral thigh
What are the changes with MAC in pregnancy?
30% decrease in MAC due to increased permeability of BBB d/t change in CVR with increase in hydrostatic pressure
fetal acidosis
fetal pH lower than maternal pH so that weak bases become more ionized in the fetus thus limiting their transfer back across the placenta
-fetal acidosis can significantly increase the fetal concentration of drugs such as local anesthetics
CO by third trimester is ____% higher than baseline
50%
CO above predelivery in early first stage labor by ____%
10%
CO in second stage labor=
40%
CO immediate post-partum
75% (125-150% increase above prepregnancy baseline)
During contractions ____ml of blood is autotransfused into central circulation.
300-500ml
post-partum CO result from:
-relief of vena caval compression
-diminished lower extremity venous pressure
-sustained myometrial contraction
-reduction in maternal vascular capacitance
CO return to prelabor values within______
24 hours
CO returns to prepregnancy levels between ______weeks
12-24
increases in what factors in pregnancy
1
7
8
9
10
12
which factors are unchanged in pregnancy
2 and 5
which factors are decreased in pregnancy?
11 and 13
What other coagulation factors are decreased in pregnancy?
PT and PTT shortened by 20%
-antithrombin III decreased
Protein S activity decreased
TEG in pregnancy
hypercoagulable
-decreased R and K values
-increase alpha angle and maximum amplitude
-decrease in lysis
Fibrin degradation factors are ______ in pregnancy
increased
Platelet count is _______in pregnancy
no change or decreased
Why is speed of induction quicker in pregnancy?
-greater minute ventilation
-reduced FRC
-despite an increased CO
Pseudocholinesteraase activity in pregnancy
-decreased by 24% before delivery and 33% on 3rd postpartum day
Uterine blood flow represents ____% CO at term
12%
(3.5% early pregnancy)
Uterine blood flow is directly proportional to _______.
uterine perfusion pressure
how much lower is fetal pH than maternal pH?
0.1-0.15
Drugs that do not readily cross placenta
-Glycopyrrolate
-Heparin
-insulin
depolarizing and nondepolarizers
-phenylephrine
-neostigmine, pyridostigmine, edrophonium
-sugammadex
What is antiphospholipid syndrome also known as?
hughes syndrome
What is antiphospholipid snydrome?
-autoimmune prothrombotic disorder characterized by the presence of lupus anticoagulant (aPL), anticardiolipin antibodies (aCL) and anti-beta2 glycoprotein I (aB2GPI)
-aPL and aCL are associated with both venous and arterial thrombotic events
How is antiphospolipid syndrome dx?
by clinical history of unexplained recurrent venous or arterial thrombosis, pregnancy loss and lab evidence of aCL or lupus anticoagulant
-may present with initial dx of ITP
maternal risks associated with antiphospholipid syndrome
-venous and arterial thrombosis
-PE
-MI
-cerebral infarction
-fetal loss
effects on the fetus of antiphospholipid syndrome
intrauterine fetal death
-triple positivity can increase risk of fetal loss
-infants born with APS don’t really have increased risk of neonatal or childhood complications
management of APS
-thromboprophylaxis with low dose aspirin and heparin
-hx of APS with thrombosis requires full anticoag during and after pregnancy
anesthesia considerations for APS
-in the absence of an underlying coag deficit or anticoagulant therapy, prolonged PTT doesn’t suggest bleeding tendency and neuraxial can be administered safely
-ASA 75-150mg daily is not a contraindication to neuraxial
GA
-higher risk of venous thrombosis
-need for compression stockings
-warm fluids, hydration
-early ambulation
-avoid dehydration and hypothermia
What is catastrophic antiphospholipid snydrome (Asherson’s syndrome)
-acute and complex biological process that leads to occlusion of small vessels of various organs
-exhibits thrombotic microangiopathy, multiple organ thrombosis and in come cases tissue necrosis and is considered an extreme or catastrophic variant of APS
-extremely rare autoimmune disorder characterized by development of blood clots affecting multiple organ systems in the body
what is arachnoiditis?
-from infectious process, spinal surgery, dye (betadine)
-neurologic condition that causes pain, stinging or burning in the back, perineum , legs arms and feet, worse case paraplegia
-adhesive arachnoiditis: chemical origin from intrathecal injection of medications with preservatives , iodine
s/s of PDPH
-hallmark in its associate with body position
-aggravated by sitting/standing and relieved by lying flat
-b/l, frontal retroorbital or occipital and extends to neck
-throbbing or constant
-photophobia and nausea
-diplopia (CN 6)
tinnitus
-results from leakage of CSF from a dural defect and subsequent intracranial hypotension
risk factors of PDPH
-young age
-female sex
-pregnancy
-size and type of needle
treatment of PDPH
-recumbent or supine position, analgesics, hydration, caffeine
-analgesic (acetaminophen, nsaids, opioids)
epidural blood patch
absolute contraindication to neuraxial
-infection at site of injection
-lack of consent
-coagulopathy or other bleeding diathesis
-severe hypovolemia
-increased intracranial pressure
Which levels do you get SNS block
T2-T6
Which levels do you get sensor block?
T8
which level do you get motor block
T10
What is preeclampsia?
-multiorgan disease characterized by new onset HTN and proteinuria after the 20th week gestation
-rarely diagnosed before 20 weeks except in gestational trophoblastic disease
Preeclampsia without severe features (mild preeclampsia)
BP>= 140/90 after 20 weeks gestation
proteinuria >= 300mg/24 h
protein creat ratio >= 0.3
edema no longer diagnostic criteria
oliguria 500-1000/day
Preeclampsia with severe features
BP>/=160/110 on 2 occasions
-thrombocytopenia (PLT <100K)
-serum creat >1.1mg/dl (or 2x baseline)
-oliguria (UOP <500ml/24 hours
-pumonary edema
-severe persistent right upper quadrant or epigastric pain
-new-onset cerebral or visual disturbances, unremitting headache
-impaired liver function
etiology of preeclampsia
-cytotrophoblast invasion is incomplete. only decidual segments undergo change
-the myometrial spiral arteries are not invaded and remodeled and thus remain small, constricted and hyperresponsive to vasomotor stimuli, this results in superficial placentation
-abnormal placentation results in decreased placental perfusion and placental infarcts predisposing fetus to growth restriction
-placental ischemia worsens throughout pregnancy as narrowed vessels are increasingly unable to meet the needs of the growing fetoplacental unit
-normal preg-embyro derived cytotrophoblast invade decidual and myometrial segments of spiral arteries replacing endothelium and causing remodeling of vascular smooth muscle and inner elastic lamina
Risk factors of pre-eclampsia
-first pregnancy
-advanced maternal age
-paternal genes in the fetus
-previous hx or family history of pre-E
-chronic HTN or chronic renal disease, DM or vascular or connective disease
-multiple gestatoin
-in-vitro fertilization, multiple miscarriages
-obesity, hispanic or black race
-protective factors:smoker (nicotine inhibition of thromboxane A-2 synthesis and/or stimulation of nitric oxide release
Skin to epidural space is ____cm in 60% of patients
4-6cm
high spinal
T4 (nipple)
used for upper abdominal surgery
can cause vasodilation and block cardioaccelerator fibers (T1-T4)
Total spinal
C8
-little finger
-difficulty breathing
-can lead to respiratory or CV arrest
most important factors affecting dermatomal spread of spinal anesthesia
-baricity of anesthetic solution
-position of patient (during and immediately after injection)
-drug dosage
-site of injection
Lipid dose >70kg
Bolus 100ml over 2-3 min then infuse 200-250ml over 15-20 min
lipid dosing <70kg
bolus 1.5ml/kg over 2-3 min
infuse 0.25ml/kg/min (IBW)`
CSF specific gravity
1.003-1.008 @ 37 C
metabolism of esters
-hydrolysis by cholinesterase enzymes-principally in plasma less in liver
-hydrolysis rate slowed in presence of liver disease and increased BUN
-metabolism may be decreased in parturients and in patients with certain chemo drugs
-patients with atypical cholinesterase mmay be at risk of developing excess systemic concentrations due to absent of limited plasma hydrolysis
potency of LA determined by:
lipid solubility
-as lipid solubility increases , the ability of LA molecule to penetrate cell membrane increases
Procaine=low
lidocaine and mepivicaine=moderate
bupivacaine and ropivacaine=high
duration of action determined by
protein binding
-lidocaine 65%=moderate
-mepivicaine 75% moderate
-bupivicaine 95% long
what is the bain circuit
coaxial version of mapleson D
-can be used for spontaneous breathing and controlled ventilation, the fresh gas inflow rate necessary to prevent rebreathing is 2.5 times the patient minute ventilation
Advantages: lightweight, convenient and disposable
disadvantages=unrecognized disconnection or kinking of the inner fresh gas hose
can cause hypercapnia or increased respiratory resistance
what is the percentage of receptors blocked with 1 twitch?
90%
what is the percentage of receptors blocked with 2 twitches?
80%
what is the percentage of receptors blocked with 3 twitches?
75%
what is the percentage of receptors blocked with 4 twitches?
0-75%
lambert-beer law
soluted concentrations measured by light transmitted through a solution
only 2 light absorbers in body: oxyhemoglobin and reduced hgb
-pulsations are caused by pulsatile arterial blood flow
2 wavelengths of light through pulsatile tissue bed
red=660 (unoxygenated)
infrared light = 940nm (oxygenated hgb)
BIS for GA
40-65
which drugs cause methemoglobinemia?
-prilocaine (EMLA cream=2.5% lidocaine and 2.5% prilocaine)
-benzocaine
-lidocaine
-nitroglycerin
-phenytoin
-sulfonamides
methemoglobinemia
-chemicals cause oxidation of hemoglobin to methemoglobin more rapidly than methemoglobin is reduced to hemoglobin
-neontaes at risk because more readily oxidized to fetal hemoglobin
-methemoglobin cannot bind oxygen or Cos resulting in loss of hgb molecules transport function
central cyanosis occurs when methemoglobin concentrations exceed 15%
-readily reversed with methylene blue
autonomic responses to heat
sweating causes active cutaneous vasodilation
sweating is mediated by postganglionic cholinergic nerves
autonomic response to cold
cutaneous vasoconstriction
mediated by alpha-1 adrenergic receptors
synergistically augmented by hypothermia induced alpha 1 and 2 receptors
what is a big cause from indigo carmine?
HTN!
inactive blue dye given IV during urologic and gyn procedures to localize ureteral orifices
dose=5ml (8mg/cc)
-can see HTN due to increased PVR with increased HR
on rare occasion=hypotension, arrest and cerebral ischemia
What drug class is methylene blue?
potent monoamine oxidase inhibitor (MAOI)
-interacts with serotonin reuptake inhibitors and SNRI
-can induce severe potentially fatal serotonin toxicity
line isolation monitor
-continuously monitors the integrity of an isolated power system
-alarm is activated between 2 and 5mA
-the reading on the meter not actual current flowing but indicates how much current would flow in the event of second failt
-does not indicate hazardous situation instead it indicated it is no longer isolated from the ground
-second fault would be dangerous
-unplug each equipment starting with the most recent until alarm stops
carboxyhemoglobin
smoking increases levels and causes shift to left
stopping smoking for 2 days can decrease levels and shift curve to right
PACU discharge scoring
-Aldrete scoring used to quantify readiness for discharge from PACU phase i
-score of at least 9/10 is required for discharge to phase 2
postanesthetic discharge scoring system (PADSS)
-a score of 9/10 is considered ready for discharge
pulsus paradoxus
systolic BP drop 10mmHg during inspiration
cardiac tamponade
constrictive pericarditis
pulsus alternas
alternating strong and weak beats
RV or LV failure
cardiomyopathy
pulsus bisferiens
systolic peaks
-aortic insufficiency and aortic stenosis
pulsus parvus Et tardus
low amplitude plse with a slow riding and late peak
-severe aortic stenosis
anacrotic limb
arterial waveforms initial upstroke
occurs as blood is rapidly ejected from ventricel through open aortic valve into aorta
ideal gas law
PV=nRT
infrared analyzer measured what
polyatomic atoms
-CO2
N20,
volatile agents
NOT O2
substantia gelatinosa
aka rexed laminae II
-plays major role in processing and modulating nociceptive input from periphery
-major site of action for opioids
-pain is modulated by a gate in the cells of the substantial gelatinosa in the spinal cord
open gate
large myelinated A delta fibers and small unmyelinated C fibers
closed gate
large A-beta fibers
What are B cells
from bone marrow
-produce antibodies involved in humoral immune response
-protect against bacteria and viruses
T cells
marrow derived
-mature in the thymus
-able to discriminate between healthy and abnormal cells involved in cell-mediated immunity
-protect against viruses and cancer
renin converts
angiotensinogen to angiotensin I
ACE converts
angiotensin I to angiotensin II
angiotensin II causes
vasoconstriction and stimulates release of aldosterone
aldosterone
increases sodium and water reabsorption in kidneys
spironolactone
aldosterone antagonist/potassium sparing diuretic
physiologic pH
7.4
Albumin role
-functions as carrier and controls plasma oncotic pressure
for every ___-g/dl change in albumin=_____mg/dl change in Ca++ level
1 gm in albumin changes Ca by 0.8mg/dl
true/false: decreased serum albumin levels are associated with hypercalcemia
false: hypocalcemia
where is albumin synthesized:
liver
Plasmin’s role
part of the fibrinolytic system/tertiary hemostasis
-counterbalance system that degrades fibrin
-plasminogen is broken down to plasmin
-plasmin breaks down fibrin into fibrin degradation products
what factors do Protein C and S inhibit??
factor 5 & 8
Thrombin
initially acting as procoagulant then acts as anticoagulant in tertiary hemostasis and activates other anticoagulant mediators
olfaction involves which cranial nerves
1 and part of 5
taste is cranial nerve
7 and part of 9
a retrobulbar block does not anesthetize cranial nerve ___ which leaves the patient able to close the eye with the orbicularis oculi but not open it with the levator muscle CN 3.
CN 7 (facial nerve)
pharynx is mostly innervated by the _______nerve
glossopharyngeal nerve
1/2 life of albumin
3 weeks
intravascular 1/2 life of albumin
24 hours
albumin is heated at _____ for ____hours to decrease risk of viral disease transmission
60 C for 10 hours
try to avoid albumin in ______patients
neurosurgical
which structure forms the structural and functional basis for integrating the neurologic and endocrine systems and is located at the base of the brain?
hypothalamus
the hypothalamus is connected to the anterior pituitary by ________
portal blood vessels
the hypothalamus is connected to the posterior pituitary by _______
hypothalamohypophsial tract
Hypothalamus produces which hormones?
-prolactin inhibiting factor
-thyrotropin releasing hormone
gonadotropin rreleasing hormone
-somatostatin
-growth hormone releasing factor
-corticotropin releasing hormone
-substance P
the basal ganglia contains:
-caudate nucleus
-globus pallidus
-putamin
-substantia nigra
-red nucleus
80% of dopamine is concentrated where?
in the basal ganglia in the caudate nucleus and putamen
What is the lowest portion of the brainstem that helps control heart rate, respiration, blood pressure, coughing, sneezing, swallowing, vomiting?
medulla oblongata
what is another name for the medulla oblongata?
myelencephalon
Medulla oblongata controls which cranial nerves
9-12
Where does the vagus nerve originate?
medulla oblongata
what is the subthalamus
part of the diencephalon
regulates movement
part of the basal ganglia
direct release of antidiuretic hormone
-synthesized in the nuclei of the hypothalamus
-stored and secreted by the posterior pituitary
-controls plasma osmolality
-causes water reaborption into the blood
-released when plasma osmolality is increased of intravascular volume is decreased
-increases blood volume by resporption of water from tubular fluid in the distal tubule and collecting duct of the nephron
________stimulates ADH secretion and thirst
Angiotensin II
what are responsible for bone maintenance?
osteocytes
-most abundant cell in bone
-develop dendritic processes that extend to either the bone surface or bone’s vascular space
-help maintain bone by signaling osteoblasts and osteoclasts to form and resorb bone
-respond to parathyroid hormone
where are osteocytes located?
lacuna (cave-like channel)
which cells help with bone resporption?
osteoclasts
-large multinucleated cells
-contain lysosomes filled with hydrolytic enzymes
-have microvilli called ruffled borders
-attached to integrins by podosomes (helps bind to bone)
where are osteoclasts located?
howship lacunae
what are the bone forming cells?
osteoblasts
-derived from mesenchymal cells
-produced osteocalcin
-form new bone
-become osteocytes that are imbedded in bone
what are bone spurs called that are seen in osteoarthritis
osteophytes
What is responsible for initiating, differentiating and committing precursor cells into osteoblasts?
transforming growth factor-beta
Amylin
-peptide hormone
-in response to nutrient stimuli, is co-secreted by beta cells
-regulates blood glucose by: delaying gastric emptying and suppressing glucagon secretion after meals
-has satiety effect
-antihyperglycemic effect
-incretins
-glucagon-like peptide (GLP-1) and glucose dependent insulinotropic polypeptide
control postprandial glucose levels by:
-promoting glucose-dependent insulin secretion
-inhibiting glucagon synthesis
-promoting hepatic glucose secretion
-delaying gastric emptying
ghrelin
-stimulates growth hormone secretion
-controls appetite
-regulates insulin sensitivity
motilin receptors
-stimulate GI peristalsis and pepsin secretion, can be a problem in patients with gastric ulcerations
-motillin is a 22 AA polypeptide found in the body
-erythromycin stimulates motilin receptors and may be a part in diarrhea SE
role of Calcium in cells
-plays a critical role in the regulation of peripheral vessel diameter. Increased Ca causes vasoconstriction and reduced intracellular Ca leads to vasodilation
-increased CAMP and protein kinase A increase intracellular calcium
phospholipase C causes ____________.
vasoconstriction
CAMP and nitric oxide cGMP cause_______.
vasodilation
PKA affects excitation -contraction couplng by:
-inhibition of voltage gates Ca channels in the sarcolemma
-inhibition of Ca release from SR
-reduced sensitivity of the myofilaments to Ca
-facilitation of Ca reuptake into the SR via the SERCA 2 pump
Catecholamines are derived from_____
tyrosine
adrenal medulla synthesizes
80% epinephrine
20% norepinephrine
prostaglandins intensify the effects of:
-histamine
-serotonin
-bradykinins
_______ which is present in cell membranes is stimulated by tissue damage.
phospholipase A2
Activation of phospholipase A 2 causes release of ______ from the phospholipid cell membrane
arachidonic acid
what is pheochromocytoma?
-caused by tumors derived from chromaffin cells of the adrenal medulla
-secretes catecholamines
clinical manifestations of pheochromocytoma
-HTN
-diaphoresis
-tachycardia
-palpitations
-severe headache
treatment of pheochromocytoma
alpha and beta blockers for HTN
Which drugs can precipitate neuroleptic malignant syndrome?
meperidine
metoclopramide
neuroleptic malignant syndrome
tx of neuroleptic malignant snydrome
-stop offending agent
-dantrolene and bromocriptine
antipsychotics possess ______ activity and may predispose a patient to central anticholinergic syndrome.
anticholinergic activity
oil: gas partition coefficient
-measure lipid solubility of inhaled anesthetic
-inversely related to MAC
-a decrease in potency associated with decrease in oil: gas partition coefficient
-the higher the oil: gas the more potent the anesthesia and lower the partial pressure required to achieve the surgical plane of anesthesia
oil: gas of sevoflurane
47
oil: gas of desflurane
19
oil: gas of isoflurane
91
nicotinic cholinergic receptors are _____ channels
ligand-gated ion channels
muscarinic receptors are
G-protein coupled
peroneal neuropathy s/s
-prolonged foot drop
-trouble ambulating
-ischemia, edma to skin and muscles
peroneal neuropathy
-injured by leg holders
-associated with direct pressure to lateral leg just below knee where the peroneal wrap around the head of the fibula
->4 hours in lithotomy increases risk of injury
saphenous nerve injury
-injured when the medial tibial condyle is compressed by leg supports
-may be injured during forceps delivery or by excessive flexion of the thigh and groin
-posterior leg
femoral nerve injury s/s
-decreased flexion of hip
-decreased extension of knee
-loss of sensation over the superior aspect of the thigh
adductor canal block indications
analgesia of knee and medial leg
-saphenous nerve
-quadriceps affected less than femoral
-sartorious medically
-vastus medialis anteriorly
-adductor muscles posteriorly
brachial plexus
formed by union of C5-T1 with some minor contributions by C4 and T2
brachial plexus passes between the ____ and ______ muscles at the level of _______.
anterior and middle scalene muscles at the level of the cricoid cartilage –> C6
How many trunks are in the brachial plexus?
3
Superior-C5-6
Middle C7
Inferior C8-T1
trunks divide into_____ and ______
anterior and posterior divisions
divisions combine to form _________
cords: lateral medial, posterior
lateral cord gives off a branch of the _____ and ends at_______.
median nerve and ends at the musculocutaneous nerve
medial cord gives off a branch of the _____ nerve and ends at the ______ nerve.
median nerve and ends at the ulnar nerve
Posterior cord gives off the _____ nerve and ends at the ______radial nerve.
axillary
musculocutaneous nerve was having pain during torniquet what cord would be blocked?
lateral cord
Are A fibers myelinated?
yes, large fibers with faster speed of impulse conduction
A-alpha
motor and proprioception
A-beta
touch
pressure
small motor
A-gamma
touch
pressure
a-delta
sharp pain
heat
cold
what is the site of action for neuraxial blockade
nerve root
are c fibers myelinated?
no, unmyelinated, slow pain, blocked easier than A fibers
B fibers
-myelinated autonomic fibers
-preganglionic SNS
-small and easiest to block with LA
-reason we end up with differential blockade
C fibers
-unmyelinated
-post ganglionic sympathetic fibers
-small, slow conduction
-dull pain, temp, touch
unpaired cartilages
- epiglottic
- thyroid
3 cricoid
paired cartilages
4 &5 arytenoids
6&7 corniculates
8&9 cuneforms
blood supply to the larynx is from
superior thyroid artery (branch of external carotid_ and also inferior thyroid artery (branch of thyrocervical trunk)
How should the NIM tube be secured
-midline
-if lubricant used it must not contain LA
-slightly larger tube size should be used to facilitate mucosal contact with electrodes
-blue band should be positioned at the level of the vocal cords
normal anion gap
10-12 mEq/L
SSEPs are sensitive to
all inhalational agents and nitrous oxide
SSEPs less affected by
IV agents
Ketamine and etomidate increase SSEP amplitude
significant changes to waveforms are
decreased amplitude by 50% and increased latency by 10%
Ketamine MOA
noncompetitive NMDA receptor antagonist that blocks glutamate
-stimulates SNS: inhibits reuptake of norepinephrine
-dissociative anesthetic
-phenylcyclidine derivative, hallucinogenic
indications of ketamine
-induction and sedation
-CV collapse
-trauma
-good for bronchospasms
Effects of ketamine CV
-intense analgesia
-CV: increased BP, HR, CO, PAP, CVP, CI
effects of ketamine respiratory
minimal depression
maintains upper airway reflexes
-increased oral secretions (glyco)
bronchodilator
neuro effects of ketamine
-increased ICP, CMRO2, CBF
dose of ketamine
IV: 1-2 mg/kg
IM: 4-5 mg/kg
Metabolites of Ketamine
norketamine-active metabolite
1/3-1/5 as potent as ketamine
etomidate MOA
ultra-short acting nonbarbiturate hypnotic, depresses RAS
effects of etomidate
-minimal CV
-decrease in CMR, CBF, ICP
-respiratory depression
-potential for increased n/V and pain on injection
-myoclonic movements
-temporary adrenocortical suppression limits long term use
metabolism of etomidate
-hepatic enzyme
-plasma esterase hydrolysis
morphine is a natural alkaloid from_____.
papaver somniferum
What is the lipophilicity of morphine?
-low
-crosses BBB slowly
-rapidly metabolized by the liver excreted via kidney (careful in compromised renal dysfunction)
fentanyl is chemically related to____.
meperidine
Fentanyl is ____X as potent as morphine
80-100X
Hydromorphone classification
semi-synthetic opioid
effects at mu-1
supraspinal analgesia
bradycardia
sedastion
pruritis
n/v
mu-2 effects
respiratory depression
euphoria
physical dependence
-pruritis
-constipation
Kappa Effects
spinal analgesia
resp depression
sedation
miosis
delta effects
spinal analgesia
resp depression
oxycodone
B-endorphin
-leu-enkephalin
What are the MAOI drugs
PICT
phenylzine (nardil
Isocarboxazid
Clorgyline
Tranylcypromate Parnate
Flumazenil MOA
competitive antagonist at Gaba a receptor to reverse benzo
Flumazenil dose
0.2mg IV over 15 sec
do not exceed 4 doses
neostigmine
-blocks hydrolysis of Ach by ACHE
-quaternary
High risk PONV adults
-female
-hx PONV/motion sickness
-nonsmoker
-type of surgery opioid analgesia
type of surgery that increase PONV
-cholecystectomy
-gyn procedures
-laparoscopic
-eye and ear
in children:
-stabismus
-adenotonsillectomy
-inguinal, scrotal, penile
early s/s of MH
increased ETCO2
tachycardia
tachypnea
mixed acidosis
masseter spasm
sudden cardiac arrest in young person due to hyperkalemia
later signs of MH
hyperthermia
muscle rigidity
myoglobinuria
arrythmias
cardiac arrest
Dantrolene dose
2.5mg/kg
is phenylephrine or ephedrine better for thyroidectomy
phenylephrine
primary goal of thyroidectomy
euthyroid before sx (min 10-14 days of meds, ideally 8 weeks before sx)
thyroid storm
-hyperthermia
tachycardia
mi, CHF
agitation, confusion
hypertension
tx of thyroid storm
-cv/vent supper
-cooling
-hr <100
-BB (esmolol/propanolol
-hydrocortisone
-PTU 200-400
-sodium iodide 250mg IV
avoid aspirin and lasix-increase thyroid levels
first sign of hypocalcemia tetany
larygneal stridor and laryngospasm
