4-2-1

Maintanence Fluids

4 ml x first 10 kg

2 ml x 10 kg

1 ml x remainder of weight

1 N

m²

V=V₁

T=T₁

P=P₁

T=T₁

PV

T

E=IR

or

P=QR

R=8Ln/∏r⁴

Laminar flow

Turbulent 

Solubility 

(Henry's Law)

K

(Equilibirium Constant)

[D]^d[C]^c

[A]^a[B]^b

aA+bB=cC+dD

E=IR

Voltage= Amperage x Resistance 

Frequency x Inductance 

or

1/(Frequency x Capacitance) 

GFCI

Ground Fault Circuit Interrupter

2000 psi

660 L

36.5 C

Therefore N2O exists as a liquid in the tank 

90-95% liquid

1590 L of gas evolves

745 psi 

Nitrogen- 78%

Oxygen- 21%

Argon- 1%

2000 psi

Decrease the pressure to 50-60 psi 

Converts variable high pressure input to a constant low pressure output 

Bourden Tubes

Should be able to read 33% higher than maximum working pressure 

shuts off other gas flow if oxygen pressure falls below 20-25 psi

Does NOT prevent a hypoxic mixture 

Floats acts as a constrictor producing turbulent flow

Gas density is the major flow rate factor 

Laminar flow is present

Viscosity becomes a major factor in gas flow

Equipped to never give gas flow with less than 25% oxygen

ONLY control oxygen and nitrous 

Concentration of anesthetic that produces immobility in 50% of patients 

When expressed as a PARTIAL PRESSURE it is indepedent from atmospheric pressure 

Fixed output vaporizer

Heats agent to 39 C to produce 1500 mmHg of pressure

Passes gas flow through a resistance and measuring back pressure to see how much Des to give 

CO₂ + Ca(OH)₂ --> CaCO₃ + H₂O 

Sodium hydroxide is a catalyst and therefore isnt created or destroyed 

14 kcal of heat is released with each mole of CO2

Resistance is about 10 cmH2O at 60L/min

Want intergranular space to be greater than tidal volume- Canisters have about 500 cc of airspace so should be changed when 1/2 exhausted 

Watch out for channeling 

1000 gram canister can absorb 200L of CO2 

CO2 and Sevo react to form Compound A

Des and Iso react with CO2 to form Carbon Monoxide 

Areas of bi-directional flow 

ETT, mask, Y piece 

Hydrophobic- pleated surface, effective for bacterial and viral filters 

Hygroscopic- more effective in increasing humidity rather than bacterial/viral effects 

TV

MV

Inspiratory Flow Rate 

8-10 cc/kg

Constant throughout life 

Anesthetic gases are contained inside the bellows

O2 is pressurizing outside of bellows

Actual tidal volume is a combination of FGF and what is inside the bellows (fresh gas flow coupling)- Tidal volumes are considerably larger than what is shown displaced by the bellows 

Volume monitoring with tidal volume adjustment

Diversion of gas during inspiration by a decoupling valve 

Halogenated agents < 2 ppm

Nitrous Oxide < 25 ppm

Halogenated agents + N2O < 0.5 ppm

10 exchanges per hour of OR air 

19 mm hose

Rigid to withstand 10kg/cm pressure

Exhaust hose from circuit to ventilator system 

Phase I

CO2 concentration should be 0

later part represents exhaled dead space 

Phase II aka Transition Phase

Lungs recoil and gas exits through trachea

Slanted if airflow is obstructed 

Usually differ between 3-5 mmHg 

Arterial is higher because some dead space is lingering about 

Increased Airway Resistance- flattening of expiratory upstroke

Cardiac Oscillation- indicate a very high cardiac output

Curare Clefts- sharp down-stroke during the expiratory plateau indicates ventilatory attempts by the patient- neuromusclar blockade warn off

Elevated Baseline- indicates rebreathing 

Ouput voltage is proportional to O2 partial pressure 

Voltage produced by the oxygenation of the lead electrode 

Applies current to reduce O2 in hydroxide anion 

Change in current is proportional to O2 in solution 

FGF- never between patient and expiratory valve

APL- never between patient and inspiratory valve

Reservoir bag- never between patient and any valve 

Bypass Valve open

Channeling

Exhaustion 

Mapelson A: 70-100 mL/kg/min for spontaneous ventilation

Mapelson D: 70-100 mL/kg/min for controlled ventilation 

30 min of battery backup

Takes 16 hrs to recharge battery

If power goes out ventilator doesnt have backup- youll have to bag

Causes vasodilation

Reduces shivering threshold 2-4 C

Affect BMR, sympathetic tone, and vascular tone 

When pressure are taken more peirpherally systolic increases and diastolic decreases

Vascular disease and vasoconstriction decrease peripheral readings up to 50 mmHg

Mean pressure is the area under the waveform 

Ring= underdampened- results in increased systolic readings 

Flattened, dampened peaks= overdampened

Crisp upstroke = hyperdynamic circulation

Broad Peak= high cardiac output

Fast flush should be 1-3 oscillations 

Diacrotic Notch= AORTIC VALVE closure 

Paper speed 25 mm/sec

0.04 sec each box 

Each bold line is 0.2 seconds

HR can be calculated by dividing 300 by the number of bold vertical lines between the QRSs

Horizontal line represents voltage: 1 cm/1mV 

Riva-Rocci

Systolic pressure is lower and diastolic is higher than with direct monitoring 

Oscillometric begins with sytolic and maximum is MAP

Oxygen Content 

(CaO2)

(1.37 x Hgb x O2%/100) + (0.003 x PaO2)

Normal is 20 cc/100 mL blood 

[1.37 x (Hgb x O2sat/100 - O2venous/100 x Hgb)] x 10 x CO 

250 cc/min

Based on the assumption that arterial blood is only pulsatile

660 oxy 940 deoxy 

Beer-Lambert 

Does not correlate with peripheral perfusion

I- Right arm to left arm

II- Right arm to left leg

III- Left arm to left leg

Augmented leads: aVR, aVF, aVL

V4- mid clavicular line 4th-5th intercostal space 

V5- anterior axillary 4th-5th intercostal space 

V6- Mid Axillary line 4th-5th intercostal space 

In precordial system: neutral electrode is formed by standard leads

MCL look at single precordial leads

MCL 5 is most common to detect lateral wall ischemia

MCL 1- MCL 6 

Lead II and V5 are the best at detecting ischemia and arrhythmias 

Amount of injectate/ area of dillution curve

Stewart-Hamilton formula

When exponential decay reaches 30% it extrapolates to minimize artifacts due to recirculation of the indicator 

Errors: reduced volume, slow injectate, warm indicator, tricuspid regurge, assumed precision

Measures phase shift in voltage across the thorax

Phase shift results in pulsatile flow

Amplitude is the magnitude of impedance, phase is the direction of impedance 

High frequency 75 kHz sine wave generator and 4 dual electrodes 

CO is measured from the average the signals from both sides 

Peak rate of change is proportional to peak aortic blood flow during each beat 

Light amplification with stimulated emmision of radiation

Coherent, columnated, monochromatic

< 0.5 mm penetration

Most commonly used b/c limits amount of tissue damage during surgery 

Damaged to cornea

Can be blocked with any type of glasses 

YAG: dark tissue, 2-6 mm, deepest penetration

Argon: 0.5-2mm hemoglobin and melanin

Damage to the retina 

Have goggles and signs

FiO2 less than 30%- N2O is flammable 

Metallic coated tubes and airway packed with soaked gauze 

No NC- if so off 1 min prior 

2 syringes available to put out fire 

Remove ETT and any flammable/burning material

Discontinue all gas flow

Pour saline into airway

Ventilate with Low FiO2 to prevent smoldering 

Sudden deceleration of a stream of electrons

Heat 99% and x-ray photons 1%

30-150 kV

Deadman switch must be held throughout exposure

X-ray scatter is what healthcare providers need to be conscious of 

Energy of x-ray beam kV

Size of the part being imaged

Duration of the imaging 

Stochastic radation is what we are worried about- cancer causing 

5 rem 

(50 mSv)

Highest radiation exposure in the OR is from Fluroscopy

NORA- CT scans 

Time- short

Distance- I₁D₁²=I₂D₂²

Shielding- 0.5 mm thick lead minimum 

Dosimetry Bag if 1/10 of yearly exposure 

Ferromagnetic Projectiles

Induction of Heat- EKG leads

Noise- 125 dB

Implanted Objects- pacemakers etc

Tattoos and Eye Makeup

Cardiac Pacemakers

ECG Changes- T wave changes from sumperimposed induced voltage 

Zone 1- free access

Zone 2- under supervision of personel

Zone 3- ferromagnetic objects can result in injury or death

Zone 4- MRI scanner magnet room 

Wave travels by compressing and rarefracting matter

Measure in frequency: number of cycles per second Hz

2.5-10 MHz diagnostic ultrasound

High frequency (5-10 MHz) great resolution, poor penetration

Low Frequency (2.5-5 MHz) great penetration, poor resolution 

Best images when transducer is perpendicular

Can be continuous or pulsed

B Mode is 2-D images and M-Mode is moving targets  

Uses low frequency ultrasound waves 

Reducing depth and size of the color box and reducing scanning sector will compensation for poor resolution

BART: blue away blood flow, red toward blood flow

Perpendicular is black

Turbulent flow is green or white