facts Flashcards
MELD components
creatinine
bilirubin
INR
range 6-40
Pre-e criteria
Mild is 1, 2 or 3 of:
BP>140/90 (2 times, 4 hrs apart)
proteinuria >300mg over 24 hrs
non-pedal edema
Severe
SBP>160 or DBP>110
proteinuria>5gm over 24 hrs
e/o severe end-organ damage w severe oliguria
cerebral headache or visual changes
pulmonary edema
epigastric pain
intrauterine growth retardation
HELLP syndrome is a form of severe pre-e characterized by hemolysis, elevated liver enzymes, and low platelets
Low plts may occur due to adherence of hte platelets at sites of endothelial damage, resulting in a consumptive coagulopathy
pao2 rule of thumb
fio2 times 5 = Pao2
ARDS criteria
1 PaO2/FiO2 ratio <300
2 acute onset (within 7 days of inciting event, e.g. sepsis, trauma, aspiration, etc)
3 bilateral infiltrates identified by chest radiography
4 respiratory failure that is not fully explained by cardiac failure or fluid overload
(mild ARDS if PaO2/FiO2 ratio is 200-300)
Aortic stenosis transvalvular gradients
mild <25
moderate 25-40
severe 40-50
critical > 50
Aortic stenosis valve area
normal 2.5 - 4 mild stenosis 1.5-2 moderate 1.0-1.5 severe 0.7-1.0 critical < 0.7
Aortic stenosis jet velocity
mild <3
moderate 3-4
severe 4-4.5
critical > 4.5
intraop factors contributing to arrhythmias
General anesthetics - volatiles, ketamine
Local anesthetics
Abnormal ABG/electrolytes (pH, hypoxia, hypercarbia)
sympathetic response to stimulation/laryngoscopy
Reflexes (vagal - brady, AV block, asystole; carotid sinus stim - brady; oculocardiac reflex - brady/asystole)
CNS stim
Dysfunction of autonomic nervous system
Pre-existing cardiac disease (MI, CHF, cardiomyopathy, valvular disease, conduction system abnormalities)
Central venous cannulation
Surgical manipulation of the cardiac structures (atrial sutures, venous bypass cannulas)
Location of the surgery (Dental - stim para and sympathetic NS; trigeminal stim can lead to stim of ANS)
Pain
Hypovolemia
Hypotension
Anemia
Endocrine abnormalities - Hyperthyroid, pheo
Temperature abnormalities (Hypo/er)
normal CI
2.6-4.2
normal PCWP
2-15 mmHg
normal PA pressure
15-30/4-12 mmHg
Normal mixed venous O2 sat
65-75%
Signs and symptoms of PE
dyspnea chest pain cough blood-tinged sputum fever tachycardia tachypnea coarse breath sounds new S4 heart sound accentuation of the pulmonic component of the S2 heart sound
GCS
Eye Opening Response
• Spontaneous–open with blinking at baseline 4 points
• To verbal stimuli, command, speech 3 points
• To pain only (not applied to face) 2 points
• No response 1 point
Verbal Response • Oriented 5 points • Confused conversation, but able to answer questions 4 points • Inappropriate words 3 points • Incomprehensible speech 2 points • No response 1 point
Motor Response
• Obeys commands for movement 6 points
• Purposeful movement to painful stimulus 5 points
• Withdraws in response to pain 4 points
• Flexion in response to pain (decorticate posturing) 3 points
• Extension response in response to pain (decerebrate posturing) 2 points
• No response 1 point
c-spine clearance criteria
absence of cervical pain/tenderness absence of paresthesias/neuro deficits normal mental status no distracting pain >4 years old
potential complications lithium
polyuria, skeletal muscle weakness, ataxia, cognitive changes, widening QRS, AV block, hypotension, seizures
anesthetic management changes for patient on lithium
1 eval for signs of toxicity (weakness, cognitive changes, ataxia, widening qrs, av block, hypoT, seizures
2 determine current lithium level
3 avoid any drugs that could lead to toxicity (thiazide diuretics, NSAIDs, ACE-i)
4 administer sodium containing fluids to prevent excessive renal reabsorption of lithium
5 watch EKG for lithiu-induced av blockade or dysrhythmias
6 closely monitor both anesthetic depth and neuromuscular blockae throughout the case (lithium can reduce anesthetic requirements and prolong effects of depol and non depol muscle relaxants)
alpha stat vs pH stat management
alpha-stat, CO2 is NOT added to maintain a PaCO2 of 40 and a pH of 7.40
pH-stat: CO2 IS added to maintain a PaCO2 of 40 and a pH of 7.40
Alpha stat = improved neuro outcome in adults (primary mechanism of brain injury is embolic not ischemic)
Pediatrics: Primary mechanism is ischemic, so pH-stat strategy is preferred (enhanced cerebral blood flow)
PCW tracing waves and what they represent
c wave - elevation of mitral valve during early ventricular systole
v wave - venous return against a closed mitral valve
x descent - downward displacement of atrium during ventricular contraction
y descent - decline in atrial pressure as MV opens during diastole
Kerley A lines
Kerley A lines are linear opacities extending from the periphery to the hila caused by distention of anastomotic channels between peripheral and central lymphatics
Kerley B lines
Kerley B lines are small, horizontal, peripheral straight lines demonstrated at the lung bases that represent thickened interlobular septa on CXR. They represent edema of the interlobular septa and though not specific, they frequently imply left ventricular failure
what is pulsus paradoxus
Pulsus paradoxus, also paradoxic pulse or paradoxical pulse, is an abnormally large decrease in stroke volume, systolic blood pressure and pulse wave amplitude during inspiration. The normal fall in pressure is less than 10 mmHg. When the drop is more than 10 mmHg, it is referred to as pulsus paradoxus
pulsus paradoxus ddx
cardiac tamponade, airway obstruction, COPD, PE
CRPS-1 diagnosis
initiating event burning pain allodynia or hyperalgesia cyanosis edema cutaneous vasomotor instability (changes in blood flow) sudomotor instability (sweating)
over time, also get
smooth/glossy skin
bone demineralization
stiff/painful joints
must exclude other causes for pain/dysfunction
dif between crps 1 and 2
CRPS-1 has specific noxious inciting event
examples of noxious events: crush injuries, lacerations, fractures, surgery, sprains or burns.
CRPS-2 develops following nerve injury, with characteristic symptoms not limited to the distribution of the injured nerve.
treatment options for crps
PT CBT anticonvulsants (gabaP) andtidepressants (amitriptylline) opioids sympathetic nerve blockade (stellate ganglion block) somatic blockade IV ketamine gtt TENS spinal cord stimulation
Pacemaker code
Paced - O, A, V, D Sensed - O, A, V, D Response - O, T, I, D Rate modulation - O, R Multisite pacing - O, A, V, D
Defibrillator code
Stock chambers - O, A, V, D
Antitachycardia pacing chambers - O, A, V, D
Tachycardia detection - E, H
Antibradycardia pacing chambers - O, A, V, D
What does a magnet do to pacemaker?
to ICD?
pacemaker to asynchronous mode
does not affect pacing mode of ICD
disable tachydysrhythmia sensing and treatment of ICDs (most)
What drugs are in ACLS and for what situations?
Amiodarone (300mg, then 150mg) - VF/PVT 2 min after epi
Lidocaine (1-1.5mg/kg, then half that) - VF/PVT 2 min after epi
Epi infusion 0.1-0.5mcg/kg/min post-cardiac arrest
Dopamine infusion 5-10 mcg/kg/min post cardiac-arrest
Norepinephrine infusion 0.1-0.5 mcg/kg/min
Atropine 1mg - bradycardia with a pulse (repeat up to 3mg)
Dopamine IV gtt 5-20 mcg/kg/min - brady with pulse
epi gtt 2-10mcg/min brady with pulse
Adenosine 6mg, then 12mg - stable wide QRS tachycardia
Procainamide 20-50mg/min - stable wide QRS tachycardia
Amiodarone IV 150mg over 10 min, then 1mg/min for 6 hours - stable wide QRS tachycardia
Sotalol - 100mg over 5 min, avoid if prolonged QT - stable wide QRS tachycardia
Adenosine - Stable, narrow QRS
B-blocker - stable narrow QRS
type of vtach for unsynchronized shock
polymorphic
BP classifications
normal 120/80 or less
pre-hypertensive: 120-139/80-89
stage 1 HTN: 140-159/90-99
stage 2: SBP 160+ or 100+ DBP
Signs of end-organ damage from HTN
LVH Angina MI CHF Stroke TIA CKD Retinopathy PAD
implications of LBBB
LBBB pattern hides ST-segment, making MI difficult to diagnose
Widened QRS could cause SVT to appear as VT
PA cath can lead to third-degree block 2/2 transient RBBB during placement
LBBB stronger association than RBBB with ischemic heart dz, aortic valve dz, LVH, CHF, HTN
avoid dobutamine (stress echo) for who
severe HTN
serious arrhythmias
hypotension
EKG abnormalities that hinder accurate computerized ST-segment analysis
LBBB WPW acute pericarditis LVH with strain digitalis effect hypokalemia
Protamine reactions
1 - pharmacologic; histamine-induced
2 - immunologic; anaphylactic vs anaphylactoid vs delayed anaphylactoid that causes noncardiogenic pulm edema
3 - catastrophic pulm HTN -> right heart failure and sig hypotension
thyroiditis ass’d with
myasthenia gravis
difficulty swallowing could be
myasthenia bulbar sx
myasthenia gravis treatment
anticholinesterase (pyridostigmine)
immunosuppresive drugs (steroids, azathioprine, cyclophosphamide, cyclosporine)
thymectomy
why avoid sux in myasthenia gravis
because the pyridostigmine may result in decreased plasma cholinesterase activity. ok to give if not yet on pyridostigmine (undiagnosed), as they will likely be resistant to sux but it may still work
cholinergic crisis signs
constricted pupils weakness/fasiculations bradycardia bronchorrea salivation nausea vomiting abdominal cramps diarrhea urinary frequency and urgency pallor diaphoresis
drug to determine if myasthenia or cholinergic crisis
edrophonium
improves strength if MG
worsens symptoms if cholinergic crisis
cholinergic crisis
cause
sx
tx
cause: overstimulation of nicotinic and muscarinic receptors at the neuromuscular junctions (usually 2/2 inhibition of acetylcholinesterase)
symptoms: S- Salivation L- Lacrimation U -Urinary frequency D-Diarrhea G- Gastrointestinal cramping and pain E- Emesis M- Miosis
treatment: consider intubation discontinue anticholinesterase administer antimuscarinics (atropine) provide supportive care consider plasmaphoresis or IV IG
neuroleptic malignant syndrome
cause
symptoms
treatment
cause - adverse reaction to neuroleptic or antipsychotic drugs.
symptoms - high fever, sweating, unstable blood pressure, stupor, muscular rigidity, and autonomic dysfunction
treatment - Generally, intensive care is needed. The neuroleptic or antipsychotic drug is discontinued, and the fever is treated aggressively. A muscle relaxant may be prescribed. Dopaminergic drugs, such as a dopamine agonist, have been reported to be useful.
circle system advantages
more effective preservation of heat/humidity
reduced waste of anesthetic agents
reduced operating room pollution
reduced dead space
normal fibrinogen levels
adults 200-400
possible DIC if below 100
severe if below 50 mg/dl
give cryo if below 50
inferior leads
ii, iii, avf
anterior leads
v3, v4
lateral leads
i, avL, v5, v6
dose epi gtt
0.01-0.05 mcg/kg/min
dose milrinone gtt
0.375-0/75 mcg/kg/min
dose NTG gtt
20-250 mcg/min
dose Nitroprusside
0.5 - 10 mcg/kg/min
doses less than 0.5 mg/kg/hr have minimal cyanide toxicity risk
dose norepi gtt
0.02 - 1.0 mcg/kg/min
phenylephrine dose gtt
0.1-5 mcg/kg/min
vasopressin gtt dosing
0.01-0.04 units/min
treatment for cyanide toxicity
discontinue offending agent
100% o2
drugs:
1 sodium thiosulfate
2 amyl nitrate or sodium nitrate
3 hydroxocobalamin
systemic effects of chronic renal failure
metabolic derangements (hyperkalemia, hyponatremia, hypOcalcemia, hypermagnesemia, hyperphosphatemia, hypoalbuminemia, uric acid accumulation, met acidosis)
periph/autonomic neuropathy seizures uremic encephalopathy anorexia delayed gastric emptying insulin resistance cardiac arrhythmias conduction blocks accelerated atherosclerosis renal osteodystrophy uremic pericarditis HTN -> LVH, CHF, CAD, CVD pulmonary edema restrictive pulm dysfunction anemia platelet dysfunction
brain swelling from hyponatremia disapears at what level
130
cancel case form hyponatremia and why?
120
that level may result in serious manifestatinos (cerebral edema, cardopulm arrest, seizures, coma, brain stem herniation)
discharge criteria from same day surgery
PADSS system vital signs activity n/v pain surgical bleeding
2 points each. 9 or higher fit for discharge
aldrete
activity breathing circulation consciousness o2 sat
score 9 or greater to dc
lung cancer association
lambert eaton
thymoma or mediastinal mass association
myasthenia gravis
von Willebrand dz:
defect of what factor
how does that factor work
type 1 vs other types
qual or quant defect in vW factor
vWF mediates platelet adhesion and aggregation and is carrier protein and stabilizer for factor VIII
type 1 = quantitative defect, impaired release but stores ar enormal
type 2 = qualitative
type 3 = extremely low levels
abnormal labs for vWF dz
mild = normal labs severe = prolonged bleeding, thrombocytopenia, prolonged PTT depending on type of dz
DDAVP treatment for vWF what types
good for type 1
bad for type 2B (causes thrombocytopenia)
prophylactic vWF replacement
cryoprecipitate or Humate P
goal in vWF dz for prophylaxis for major surgery
vWF:RCo and factor VIII levels greater than 100
direct acting inotrope
isoproterenol
list of antihypertensive drugs
nitroglycerin sodium nitroprusside phentolamine esmolol labetolol magnesium diltiazem?
apnea-hypopnea index formula and scale
dividing the number of apnea events by the number of hours of sleep
severe >30
moderate 16-30
mild 5-15
RVSP pulm htn severity scale
normal <35
Mild 35-45
moderate 46-60
severe >60
Mean PA Pressure pulm htn severity
mild <30
moderate 30-45
severe >45
Systolic PA Pressure pulm htn severity
mild 40-60
moderate 60-90
severe >90
lipophilic drug classes
benzos, opioids, barbiturates
hydrophilic drug example
neuromusclar blocking agents
initial loading dose lipophilic based on what weight
total body weight bc larger volume of distribution 2/2 increased deposition into body fat
maintenance dose lipophilic drugs base on what weight
ideal (increased clearance time)
reasonable approach to dosing drugs for obesity
start with IBW, then titrate to effect as effects of obesity on drugs is unpredictable.
post op management and
predictors of severe myasthenia
Ensure that the patient is reminded prior to induction of the possibility of a prolonged intubation.
Extubation: performed on awake patients and hopefully close to his/her baseline status. Reinstitute anticholinesterase medication, either by IV infusion or by reimplementation of the patient’s oral regimen.
Leventhal criteria: Predictive scoring system for the need for postoperative ventilation
1) duration of disease for 6 years or longer
2) chronic comorbid pulmonary disease
3) pyridostigmine dose >750 mg/d
4) VC <2.9L
5) Other indicators include preoperative use of steroids, and previous episode of respiratory failure.
These predictors have not been widely validated. (1)
Drugs to avoid: Calcium Channel blockers, Magnesium, Aminoglycoside antibiotics as all of these may contribute to muscle weakness
Post-Op Bed: Patients should be monitored in either a ICU or step-down unit but NOT to a conventional surgical ward.
closed circle system
gas reservoir bag - yes rebreathing exhaled gases - total chemical neutralization of co2 - yes unidirectional valves - three fresh gas inflow rate - low
advantages: maximal humidification and warming, less pollution of atmosphere, economy in use of anesthetics
disadvantages: inability to rapidly change the delivered concentration of anesthetic gases and o2 becasue of low FGF, unpredictable concentration of o2, unknown conc of anesthetic gas
semiclosed circle system
this is what our vents are
gas reservoir bag - yes rebreathing exhaled gases - partial chemical neutralization of co2 - yes unidirectional valves - three fresh gas inflow rate - moderate
some conservation of heat and moisture
decreased pollution of surrounding atmosphere
increased resistance from valves/co2 absorbent
enhanced opportunity for malfunction 2/2 complexity of apparatus
semiopen circle system
Maplesons
gas reservoir bag - all but E rebreathing exhaled gases - no (if adequate FGF) chemical neutralization of co2 - no unidirectional valves - one (none in E) fresh gas inflow rate - high
For mapeson F (Jackson-Rees) disadvantages: need for high FGF possibility of high airway pressure/barotrauma lack of humidification
open circle system
gas reservoir bag - no rebreathing exhaled gases - no chemical neutralization of co2 - no unidirectional valves - no fresh gas inflow rate - unknown
fena prerenal
less than 1%
post op delirium vs post op cognitive dysfunction
delirium 1-3 days post op acute state of confusion significant morbidity multiple causes: metabolic, sepsis, pain, disorientation, etc treat underlying cause may benefit from haloperidol
POCD not acutely confused of agitated weeks/months later usually resolves in 6-12 months increased mortality rate unknown role of anesthetics
Where mixed venous blood drawn from
tip of PA catheter
it is usually higher than ScvO2 (ScvO2 contains predominantly SVC blood - brain has higher O2 extraction, but anesthesia can alter that)
porphyra
defect in heme biosynthetic pathway -> overproduction of porphyrins
type of porphyria depends on enzyme deficiency
acute forms of porphyria are inducible by medication, can be life-threatening. ab pain, n/v, psych disturb, ANS instability, electrolyte disturb, hypovolemia, seizures, weakness, resp failure
preop: H&P, severity, precipitating factors, treatment, symptoms; neuropathy, ANS intability, weakness, electrolytes, fluid status
if in exacerbation, delay elective surgery
reduce risk: avoid fasting, dehydration, stress, infection, D10NS, check what drugs are safe
use regional
porphyric crisis treatment: dc pophyrinogenic drugs, supportive care, D10NS, treat nausea, correct lytes, treat seizures with benzo or prop; if no improvement after 2 days, consider hematin
physiologic effects of ECT
parasympathetic before sympathetic
drug keeps pda open
prostaglandins
NSAIDs inhibit prostaglandins
after ect: disorientation, inability to consistently follow commands, motor agitation
postictal agitation
treat with benzo or dexmedetomidine
Recurrent and superior laryngeal nerve interaction and function and how to block
recurrent laryngeal - sensory cords and trachea, intrinsic muscles of larynx; transtracheal block
superior laryngeal - sensation above cords (internal), cricothyroid muscle (external); block with needle at greater cornu hyoid bone
APGAR score
Appearance Pulse 0, 0-100, 100+ Grimace Activity Respirations
anticholinergic does what to bronchi
bronchodilates
