Chapter 1 Flashcards
Intrascalene block doesn’t block what nerve
What dermatome
Ulnar nerve
C8-T1
Neuraxial block level of blockade
Which is first second third from bottom up
Sensory motor sympathetic
Motor is lowest
1 dermattome above sensory
1 more dermatome above is sympathetic
Intercostobrachial nerve innervates what dermatome
T2
Dorsal respiratory center initiates
Ventral respiratory center initiates
Inspiration is dorsal
Passive exhalation is ventral
Apnustic center in pons sends signals to dorsal respiratory center in medulla to
Sustain inspiration.
Reticular activating system does what?
Where is it found
Increases ventilators rate and volume of inspiration
Found in midbrain
Bezold jarish reflex
Parasympathetic leading to bradycardia vasodilation and hypotension when stimulating cardiac myocytes
Carotid body chemoceptors interact with respiratory centers via which nerve
Glossopharyngeal
Aortic arch chemocepters deliver signal via what nerve
Vagus
Infarct of the hypothalamus would involve which artery
Anterior cerebral artery
Which artery supplies broca and wernickes area
Middle cerebral artery
Gray matter of spinal cord
Consists of neurons andneuroglia
Butterfly shaped
Gray to white matter ratio is highest at cervical and lumbar regions
Dorsal column tract
Ascending signal pathway
First order neurons are in dorsal root ganglion
Second order in dorsal horn
Third order in hypothalamus
For fine touch, proprioception, vibration
Reticulospinal tract
Descending for voluntary movement and reflexes
Corticospinal tract
Descending or ascending
Descending that innervates skeletal muscle
Descending pathways generally how many neuron system?
First order is in what cortex
3
Cerebral cortex
Spinothalamic tract
Pain and temperature
Meningies main function
Protect brain and spinal cord from injury
Blood supply to skull and hemispheres
Space for CSF
They do not produce CSF
This is formed by the lateral cerebral ventricles of the choroid plexus
Which layer of meningies is pain sensitive
Dura mater
Between arachnoid and pia is the
Subarachnoid space
CPP is primarily determined by the
Normal CPP range
MAP
80-100 mm/hg
CBF increases 1-2 ml/100g per minute for a
Increase in co2
H+ does not cross blood brain barrier thus
Does not affect cerebral blood flow
Auto regulation is constant at maps of
Higher blood pressure causes autoregulation curve of CBF to shift
60-160 map
Right
Volatile anesthetics
Dilated cerebral vessels
Impair autoregulatoon
Increase CBF
Circulatory steal
Giving blood to normal areas of brain instead of ischemic areas
Volatile anesthetivs increase CBF when above
Ketamine increases
Nitrous oxide increases
1 MAC
ICP
CBF
Nitrous oxide increase
CBF and CMR02
Volatile anesthetivs decrease CMRO2
Halothane causes the most increase in cerebral blood flow, Sevoflurane the least
Which volatile anesthetivs facilitates CSF absorption
Isoflurane
To prevent neuronal damage you don’t need
Tight glucose control
Makes patient hypoglycemic leading to more issues
Arachnoid villi absorb
How much CSF volume is maintained
CSF
100-150 ml
Production of CSF is by
Lateral cerebral ventricles of choroid plexus
Furosemide, acetazolamide, thiopental decrease CSF production
Ketamine increases
CSF production
Halothane impedes CSF
Absorption
Barbiturates can help in the brain with
Focal, not global ischemia
Etomidate increases cmrO2
In neurosurgery cases high PEEP
Should be avoided! Increses I tear Horacio pressure and may impede cerebral venous drainage worsening icp
Fentanyl has minimal affect on
Elevating head of bed can decrease
ICP and CBF
ICP
Fev1/FVC ratio
Can provide indication of degree of airway obstruction
Normal subjects can expire 75-85% of FVC in one sec
FVC
Volume of gas expired forcefully after maximal inspiration
Usually equal to VC
FRC =
Volume remaining in lung after passive expiration
TLC =
VC + RV
IRV plus tidal volume =
IC
MVV largest volume that can be breathed in 1 minute with voluntary effort
MVV usually normal in restrictive lung disease
FRC decreases when you
Lay down
Laplace law = 2T/R
Net pressure for inflation of the alveolus
Type 2 alveolar cells produce
Surfactant
Type 3 alveolar cells are
Macrophages
On flow volume loop
COPD has concave expiratory portion which is the effort independent portion of expiration
Flow volume loop tracheal stenosis
Both inspiratory and expiratory curves are decreased compared with baseline
Lung parenchyma
Respiratory bronchioles, alveolar ducts, alveoli,
More negative intraeural pressure at the
Apex of the lung
Most tidal volume reaches the gravity dependent portion of the lung
Blood flow into lungs is
Gravity dependent
West zone 1 gets ventilation in absence of perfusion
Ideal V/Q ratio is 1:1 occurs at what rib space
3rd
No perfusion =
Dead space
Direct inhibitors of HPV
Infection
Vasodilator drugs
Hypocarbia
Pa02 of 20-40
Saturation goes to 25%
Hyperoxia
Lowers ICP
Respiratory center
Located in the brainstem(pons and medulla)
Peripheral chemoceptors made up of
Carotid and aortic bodies
Stimulated by decrease in pa02
Central chemoreceptors are primarily sensitive to
Hydrogen ion concentration
Carbon dioxides effect is indirect
Ventilator rhythmicity controlled by
Dorsal medullary reticular formation
Dorsal respiratory group contains inspiratory centers
Above what pa02 do you not influence carbon dioxide response curve
100
Beta 2 on bronchial smooth muscle leads to formation of
cAMP
Leukotrienes
Arachodonic acid metabolites
They antagonize the leukotriene receptor
Dexametbasone has more anti inflammatory than
Hydrocortisone
Most energy used in cardiac cycle is during
Isovolumetric contraction
Frank starling relationship
Relationship between preload and contractile performance
Early indicator of MI are increased LVEDV and decreased compliance
ECG wall motion abnormalities are later findings
Sv02 is oxygen utilization in body
Mixed venous is measured in
Pulmonary artery
Increased hemoglobin, increased cardiac output will increase sv02
If you use more oxygen such as in hyperthermia will lower sv02
Diastolic dysfunction
Impaired relaxation of LV
E to A ratio is less than 1
Pressure baroceptors r located in the carotid sinus and aortic arch
SA and AV node decrease heart rate and vascular tone to decrease blood pressure
SBP is higher in femoral artery than in the
Aorta
Diaphragm goes down it drops
Intrathoracic pressure
Most blood lies in the
Venous system
Compliance of venous system
Much higher to that of arteries
Capillary blood flow
Determined by
Transmural pressure and tone of precapillary and postcapillary sphincters
Tissue with greatest capillary density
Are tissues with high metabolic rate such as heart and skeletal muscle
How much of cardiac output goes to liver
25%
CPR should continue for
At least 2 minutes after return of spontaneous circulation after defibrillation
Asystole
First medication after starting CPR is epinephrine 1mg
Symptomatic bradycardia
12 lead
Atropine 0.5 mg every 5 minutes
Then do transcutaneous pacing, epinephrine 2-10 ug/min or dopamine
Dilute drugs with 10ml saline when administered via
Endotracheal tube
Narrow complex tachycardia
Initial is
vagal manuever
Adenosine 6mg is next then 12mg
STEMI management
Door to balloon time of 90 minutes
Door to needle time 30 minutes fibrinolysis
Emergency room of 10 minute or less
With an mi with papillary muscle the one most likely to rupture is the
Posteromedial papillary muscle
Posterior interventricular artery is located in the
Inferior interventricular groove
Mitral valve has two leaflets
Anterolateral and posteromedial
What structure is responsible for conduction of impulses from right to left atrium
Bachman bundle
Best vasoactive agent for aortic stenosis
Phenylephrine
Conduction velocity is fastest through the
His-purkinjee system
C wave
Isovolumetric Ventricular contraction
Don’t give neostigmine to
Heart transplant patients
A wave
Atrial contraction
Diastolic dysfunction
Increased stiffness of ventricle, higher pressure
V5 lead best for
Lateral wall ischemia
Rhythm and conduction disturbance
Lead 2
Tachycardia helps with
Mitral regurgitation
WPW has an
Accessory pathway avoid AV nodal blocking agents like metoprolol and verapamil
Complications of trans catheter aortic valve replacement
Embolus stroke, hematoma, MI, LBBB or complete heart block
S3 is for and is
S4 is for and is
CHF/transient
Non compliant ventricle and is permanent
Severe tachycardia ca lead to
MI - hypokalemia can not
Acetylcholine acts on M2
Receptors to slow heart rate
Reverse T puts blood in the legs leading to a decrease in
Venous return
Diastolic dysfunction patients rely on the
Atrial kick
Midline fold on dura can lead to
Unilateral epidural
Renin release is increased in
Cirrhotic patients
Cirrhotic patients
Vasodilation decrease SVR and increases cardiac output
Retrograde intubation contraindications
Coagulopathy
Faint identify landmarks
Thyroid goiter
Systolic filling of atrium =
V wave
Atrial relaxation =
X descent
CRRT is ideal hemodialysis for
Unstable patients in the ICU
If you change pac02 what changes the most is
Cerebral blood flow
1-2 ml100g change for each 1mm change in pac02
First line treatment for cyanide toxicity is
Hydroxocobalamin
Cyanide inactivates cytochrome oxidase
Plasma creatinine x urine sodium/urine creatinine x plasma sodium =
FenA
Myotonic dystrophy
Muscle disorders with prolonged contraction and muscle relaxation.
Type1 due to CTG repeats
Propofol can lead to direct
Mitochondrial toxicity, leading to respiratory system dysfunction and impaired fatty acid metabolism
Central cord syndrome
Cervical spinal cord injury, resulting in loss of sensation and motor function in upper extremities
LR is metabolized to
Bicarbonate via mitochondria. Don’t give LR to patients with mitochondrial disease as it leads to elevated serum lactate and metabolic acidosis
Alcoholism and obesity increase
Psuedocholinesterase activity
They decrease in pregnancy
Dichotomous variable =
Nominal =
Continuous
2 categories available
2 or more categories with no order
Can take on infinite number of values
Ordinal are in groups such as small medium or large
Paired T test
Only one group of individuals
Chi square is used to evaluate
Two categorical variables
Like comparing PONV and red hair
Compare means of more than 2 groups with
ANOVA
Odds of something occurring =
Probability it occurs/(1-probability)
Positive skew
The tail is to the right
Sensitivity
Measures populations of individuals with the disease who are correctly identified as having the disease by the test
PPV
A test that is positive indicates the true prescence of the disease
Cohort study
Observational study are subjects chosen and followed over period to observe outcome of interest
Cross sectional
Survey
Type 1 error
Reject the true null hypothesis
Increased SD
Increased variability
NNT
Number of patients who need to be treated to prevent one adverse outcome
Best NNT is
1- because for each you treat don’t need control. The higher the NNT the less effective the treatment
Survival analysis between two comparable treatments is looked at with
Hazard ratios
Crossover in statistics means
Patients who receive a sequence of different treatments during the trial
Single blinded means you are blinding only to the
Subjects
P value
Obtaining test statistic value equal to or more extreme than actual test statistics given the null hypothesis is true
R time on TEG is prolonged. What do you give to treat?
FFP
Normal R time is 6-8 minutes
Decreased F time is treated with anti-fibrinolytic such as
Transexamic acid
Alpha angle is a reflection of clotting kinetics. If decreased it’s due to low fibrinogen and treat with
Cryoprecipitate
What nerve is in close proximity to brachial artery
Median nerve within antecubital fossa
A line
Pressure transducer converts to electric signal
Flush test on A line system to look if dampened
Should get 1 large and 1 small oscillation before return to baseline
Overdampened systems
Attenuate true arterial pressure waveform leading to low pressures and low pulse pressure
Overdampening causes are kink in line and bubbles in fluid tubing
Underdampening makes systolic look higher and thus can be due to excessive length of tubing
As arterial pressure moves away from aorta the systolic portion becomes peaked/narrowed with increased amplitude
This dorsalis pedis has about 20 mmHg higher systolic shown that at aorta
A wave of CVP
Atrial contraction at end of diastole called atrial kick
C wave isovolumetric contraction against a closed tricuspid valve resulting in back pressure through atrium to CVP catheter
X descent- midsystole due to atrial relaxation
This is not found in junctional rhythm
In junctional rhythm contraction of right atrium occurs against closed tricuspid resulting in exaggerated A wave called a canon A wave
Tall C wave with
Tricuspid regurgitation
Right IJ is typically
Lateral and anterior to carotid artery
Peripheral insertion of central catheter
Best is basilic which runs medial
Catheter induced pulmonary artery rupture is
Hypoxia secondary to lung spillage of contents
Compliance =
Change in volume/ change in pressure
Static compliance =
Tidal volume /(ppleateau- peep)
Pressure control
Pleateau is horizontal
Volume control pleateau is concave down
PEEP
Recruits collapsed alveoli and thus increases pulmonary compliance
Causes FRC to increase
Positive pressure Ventilation
Decreases preload, afterload, and increases cardiac output
Increased intrathoracic pressure lowers venous return
PPV leads to peak systolic transmural wall pressure to be decreased and afterload is decreased
Oxygen face mask Fi02 from 5-10 liters is
.4-.6
NC Fi02
2 liters is .24-.28
3 liters .28-.32 and then goes up by 4
Nonrebreather can hit anFi02 of
1, partial rebreather hits an Fi02 of 0.75
Both have a bag for expired gas to go out of
Venturi mask
A fixed Fi02 is given based on entrainment port of mask, independent on patients minute ventilation
A Paced if pacer spike is before
P wave
Different morphologies of P waves are seen in what rhythm
MAT
Get heart rate control with beta blockers
Don’t need cardiac consult
D Shaped left ventricle on mid papillary view seen in
Pulmonary embolisms bc of shift of interventricular septum toward left ventricle
RV is above LV usually I this view
VOO mode can lead to
Under sensing of cardiac activity and can lead to pacer spike before T wave leading to R on T phenomenon
Leading to V fib
Treat by switching pacing mode to DDD
MAP =
Cardiac output x SVR