Formulas 2 Flashcards
Axillary
Arm abduction (deltoid)
Musculocutaneous
Elbow flexion (biceps)
Median
Thumb opposition
Radial
Elbow extension (triceps) Wrist and finger extension
Ulnar
Pinky finger abduction
Femoral triangle borders
SAIL
Sartorious- medial
Adductor longus- lateral
Inguinal ligament- superior, b/w ASIS and pubic tubercle
Ankle block nerves clockwise
(From achilles) Tibial nerve Saphenous nerve Deep peroneal nerve Superficial peroneal nerve Sural nerve
Ankle pneumonic
TIPPED
Tibial inversion plantar flexion
Peroneal eversion dorsiflexion
Ulnar nerve injury
Ulnar- claw hand
most common intraop injury
Median nerve injury
Median- inability to oppose thumb
AC IV sticks and axillary blockade
Radial nerve injury
Radial- wrist drop
direct compression on spiral groove of humerus
DO2
1000 mL/min
normal oxygen extraction ration = 250mL/min (25% of CO)
normal CO
HR x SV
5-6L/min
CaO2
20 mL/dL
VO2
250 mL/min at rest
CvO2
15mL/dL
Ohms law
Flow= pressure gradient /resistance
MAP= (CO x SVR) /80) + CVP
Poiuselle’s law
(pie x R(to the 4th power) x change in pressure) / (8 x n x l)
Reynolds number
<2000= laminar
2000-4000= transitional
>4000=turbulent
CI
CO/BSA
2.4-4.2 L/min/m(squared)
SV
EDV-ESV
CO x (1000/HR)
50-110 mL/beat
SVI
SV/BSA
EF
((EDV-ESV)/EDV) x 100
(SV/EDV) x 100
60-70%
LV dysfunction when less than 40%
MAP
(1/3 x SBP) + (2/3 DBP)
((COxSVR) /80) + CVP
70-105 mmHg
Pulse pressure
SBP-DBP
stroke volume output/arterial tree compliance
40 mmHg
SVR
((MAP-CVP/CO) x 80
800-1500 dynes/sec/cm to the -5th
arteriolar resistance, doesn’t take viscosity or other factors of afterload into account
SVRI
((MAP-CVP/CI) x 80
1500-2400 dynes/sec/cm to the -5th/m squared
Ventricular output measurement
CO, SV, LVSW, RVSW
Filling pressure measurement
CVP, PAD, PAOP, LAP, LVEDP
End diastolic volume
RVEDV
LVEDV
% of CO in atrial kick
20-30%
PVR
((mPAP- PAOP)/CO) x 80
150-200 dynes/sec/cm to the -5th
Law of Laplace
wall stress= (intraventricular pressure x radius)/ wall thickness
SA node blood supply
RCA: 50-60% of people
CxA: 40-50% of people
Coronary artery dominance
RCA supplies PDA= right dominance
CxA supplies PDA= left dominance
RCA and CxA supply PDA= co dominance
myocardial oxygen extraction
70%
very efficient
coronary sinus saturation= 30%
coronary blood flow
coronary perfusion pressure/coronary vascular resistance
coronary perfusion pressure
Aortic DBP- LVEDP
or DVP-PAOP
coronary autoregulation
MAP 60-140 mmHg
coronary blood flow
225-250mL/min
4-7% of CO
myocardium O2 consumption
8-10 mL/min/100g
conditions that set SVR proximal to systemic circulation
aortic stenosis
hypertrophic cardiomyopathy
coarctation of the aorta
Ca-v difference
(1.34 x hgb x SpO2)- (1.34 x hgb x SvO2)
normal CaO2= 20 mLO2/ dL blood
normal CvO2=15 mLO2/ dL blood
normal Ca-v difference= 5 mLO2/ dL blood
aortic valve orifice
norm: 2.5-3.5 cm2
severe stenosis: <0.8cm2
triad of aortic stenosis
Syncope-3 years
Angina- 5 years
Dyspnea- 2 years
mitral valve
normal orifice: 4-6 cm2
severe stenosis: <1cm2
LAP-LV gradient exceeds 10 mmHg
PASP >50mmHg
greatest risk factor for cardiac probs with non cardiac surgery
unstable angina
best EKG leads to monitor for ischemia
V3>V4>V5>III>aVF
best EKG leads to assess for ST changes in patients with CAD
5 lead: V3, aVf, MCL5 or III
3 lead: aVf and MCL5
best leading for monitoring arrhythmia
II
ventricular compliance
ventricular volume/ventricular pressure
most common cause of secondary hypertension
renal artery stenosis
CCB impairing contractility
verapmail>nifedipine>dilt>nicardipine
Beck’s triad
muffled heart tones- from fluid accumulation in pericardial sack
jugular vein distention- decreased venous return in R heart
decreased SV- hypotension
Pulsus paradoxis
decreased SBP by >10mmHg during inspiration
Kussmahl’s sign
increased JVD and and CVP during inspiration
determinants of outflow through LVOT
systolic LV volume
force of LV contraction
transmural pressure
duration after cardiac stents to wait for elective surgery
bare metal stent: 30 days
DES:first generation 12 months, second generation 6 months, 12 months minimum with acute coronary syndrome
Becks syndrome
From Artery of Adamkiewciz occlusion of anterior cord in T11-T12 Bowel and bladder dysfunction Flaccid paralysis of lower extremeties loss of temp/pain Preserved touch and proprioception
Gas vapor pressures
Sevo- 157
Iso- 238
Des- 669
Nitrous- 38770
Gas blood gas solubility
Sevo- 0.65 Iso- 1.45 Des-0.42 Nitrous- 0.46 Nitrogen- 0.014 (N2O enters space 34x more than nitrogen can exit)
CO per tissue group
VRG- 75% CO, 10% body mass
Muscle and skin- 20% CO, 50% body mass
Far- 5% of CO, 20% body mass
Non VRG- <1% CO, 20% body mass
MAC values
Sevo- 2
Iso- 1.2
Des- 6.6
Nitrous- 104
Meyer overton hypothesis
lipid solubility is proportional to the potency of anesthetic agent
Ficks law of diffusion
Directly proportional- partial pressure difference, solubility coefficient, membrane surface area
Inversely proportional- membrane thickness, molecular weight
ideal gas law
PV=nrT
n= number of moles
r=0.0821 liter-atm/K/mole
conceptually P=T/V
law of Laplace in L ventricle
(LV pressure x radius)/ (LV wall thickness x 2)
Exposure to radiation
5 rem per yer
0.5 rem per year in pregnancy, 0.05 rem per month
Distance from radiation
6 ft away= 9 inches of concrete of 2.5mm lead
intensity- 1/distance squared
Critical temp of common gasses
N2O- 36.5 CO2- 31 Oxygen- -119 Air= -140 N2= -147
Celsius and Kelvin
Celsius= K - 273.15
Celsius and Fahrenheit
F= (C x 1.8) +32
Boiling point of H2O
100 degrees C
212 degrees F
Freezing point of H2O
0 degrees C
32 degrees F
Pressure
Force/area
Pressure conversion
1 atm= 760 mmHg= 760 torr= 1 bar = 100kPa= 1033 cm H20 = 14.7 lb/inch squared
1mmHg= 1.36 cm H20
Avogadros number
6.023 x 10 to the 23rd atoms
Molecular weights
helium= 4 g
oxygen=16 g, 1 mole=32 g
Mechanisms of heat transfer
Radiation (60%) >convection (15-30%) > evaporation (20%) > conduction (<5%)
ingredients to produce fire
ignitor
fuel
oxidizer
Burn body % adult
Head 10% Trunk 36% Leg 18% Arm 9% Perineum 1%
Burn body % kid
Head 19% Trunk 32% Leg 15% Arm 9.5% for every year >1 year up to 10 years, head BSA decreases by 1% and leg increases by 0.5%
Fluid replacement in burns
24 hours: 2 ml x % TBSA burned x kg
or 4 mL, use crystalloid (1/2 in first 8 hours, rest in 16 hours)
2nd 24 hours: D5W maintenance rate, 0.5mL x % TBSA burned x kg
TAP block districution
T9-L1
Barrier pressure
lower esophageal sphincter pressure - intragastric pressure
Reduced barrier pressure= increased reflux
Samter’s triad
Aspirin exacerbated respiratory disease
nasal polyps, allerigic rhinitis, and asthma
BMI
kg/m2
1 inch= 2.54cm
IBW
men (kg)= height in cm- 100
women (kg)= height in cm -105
CO increase per kg of fat
100 mL/min
Drug dosage calc in obesity
Water soluble drugs calculated to IBW
Fat soluble drugs calculated to TBW
Vd for lipid soluble drugs»_space; Vd for water soluble drugs (but both increase)
TBW drugs
Prop induction Midazolam Succ Fent Cis
LBW drugs
Prop maintenance Remi Roc Vec Fent maintenance
Apnea/hypopnea index
mild= 5-15 episodes/hr moderate= 15-30 severe= >30
STOPBANG
Snore? Tired? Observed apnea? Pressure? BMI >35? Age>50? Neck circum >45cm? Male gender?
high risk= >3 questions answered yes
6 elements of informed consent
competence decision making capacity disclosure of information understanding of disclosed info voluntary consent documentation
4 pieces of malpractice
- duty
- breech of duty
- causation
- damages
res ipsa loquitur
“the thing speaks for itself”
injury would not have occurred without negligence
injury causes by something under the complete control of the provider
pt did not contribute in any way to injury
evidence for explanation of event solely under control of provider
Causes of anesthesia related lawsuit
- death
- nerve damange
- permanent brain damage
- awareness
increased risks of dying within 7 days of surgery
- physical status
- emergency vs. elective surgery
- major vs. minor surgery
- patient age (80 vs 60)
airway management claims
most common for cause of death
- inadequate ventilation
- unrecognized esophageal intubation
- difficult airway
paren patriae
father of the country
government serves as legal protector of citizens who can’t protect themselves
% of anesthesia mistakes related to human error
70%
Lifetime rem
(N-18) x 5
n=age in years
Noise limits
8 hour exposure= 90dB
single noise= 115dB
Triple aim
improving patient experience
improving population health
reduced per capita costs
6 domains of high quality health care
patient centered- dignity, respect, informed sharing, collaboration safe effective timely efficient equitable
BP changes with cuff height
10 cm= 7.4 mmHg
1in= 2cm Hg