Equipment + Monitoring Flashcards
Agent most likely to cause circuit fire
Sevoflurane
What Sp02 does and does not monitor
Does monitor:
- Hgb saturation
- HR
- fluid responsiveness
Does not monitor:
- amount of Hgb (anemia)
- Ca02
- D02
- ventilation (can have normal Sp02 with hypercarbia)
Best Maplesons for CV and SV
SV: A>DFE>B
CV: D>FE>BC>A
Soda lime chemical RXN
C02 + H20 → H2C03
H2C03 + 2NaOH → Na2C03 + 2 H20 + energy
Na2C03 + Ca(OH)3 → CaC03 + 2NaOH
Difference between semi open and semi closed breathing circuits
Semi closed allow rebreathing of exhaled gas.
→ FGF MV
Line isolation monitor - what does it assess and what does it tell you when it alarms
- Assesses the integrity of the ungrounded power system in the OR.
- Tells you when the OR becomes grounded, and how much current could flow thru you or a patient if a second fault occurs.
- If it alarms, it means its alerting you to a FIRST fault (means OR has become grounded)
- Will alarm when 2-5mA of leak current is detected
Mechanical events of R heart as they correspond to CVP waveform
A wave = RA contraction
C wave = RV contraction (specifically isovolumetric contraction + bulging of tricuspid towards RA)
X descent = RA relaxation
V wave = passive filling of RA
Distances from CVL insertion points to vena cava/RA junction
L or R subclavian: 10cm RIJ: 15cm LIJ: 20cm Femoral: 40cm R median basilic: 40cm L median basilic: 50cm
How to predict how long your agent will last
ML agent used per hour = Vol% x FGF (L/min) x 3
How to calculate volume lost to circuit compliance
Circuit compliance (mL/cm h20) x peak pressure (cmH20)
Compensation for TEC-6 DES vaporizer at elevation
Higher altitude → higher setting on dial
Lower altitude → lower setting on dial
At higher altitude, the [] exiting vaporizer will be whatever you set on dial, but bc atmospheric pressure is lower at elevation, the partial pressure in the breathing circuit will also be lower.
What can the oxygen analyzer do that other components cant
-Can detect an 02 pipeline crossover (o2 pressure device and proportioning systems can’t)
-Monitors 02 CONCENTRATION
-Can detect a leak in breathing circuit
→ most common is Y-piece
→ 2nd most common is C02 canister
What to do if the oxygen analyzer alarms
Turn ON the 02 cylinder, THEN kill the pipeline supply
→ if a crossover occurred and you just turn on the tank, that won’t fix the problem , because if an adequate pipeline pressure is present even if it’s not 02, the machine will still draw from the pipeline
→ any time you switch to a tank you gotta kill the pipeline
What are the final products of the soda lime reaction
Calcium carbonate (CaC03) Sodium hydroxide (NaOH)
Advantages, disadvantages of Amsorb plus (calcium hydroxide lime)
A: no CO production, v little Compound A production, stays moist
D: $, absorbs less C02
(Amsorb = 10L C02/100g, Soda lime = 26LC02/100g)
OSHA recs regarding IA agent exposure
Halogenated alone <= 2ppm
N20 alone <=25ppm
IA + N20 <=0.5ppm and 25ppm respectively
What would cause ↑ PIP and ↑ plateau pressure?
Means TOTAL compliance has ↓
- Endobronchial intubation
- Pulmonary edema
- Tension pneumo
- Atelectasis
- Chest wall edema
- Insufflation
- Ascites
- Tburg
- Inadequate paralysis
→ of ↑ PIP with NO change in Peak pressure
Means resistance has ↑
- kinked ETT
- ETT cuff herniation
- Bronchospasm
- secretions/plug
- Airway compression
- foreign body aspiration
→ of ↑ alpha angle on capnograph
Signifies expiratory airflow obstruction: COPD, bronchospasm, kinked ETT
“Shark fin” shape
→ of ↑ beta angle on capnograph
Faulty unidirectional valve
Distance of PA from VC junction
25-35cm
Complications of floating PA cath
PA rupture
RBBB
Complete heart block (if pre existing LBBB)
Dysrhythmias
Things that ↑ CVP
Transducer below axis Hypervolemia RV failure Tricuspid stenosis or regurgitation Pulmonic stenosis Pulmonary HTN PEEP VSD Constrictive pericarditis Cardiac tamponade
→ of ↑ A wave amplitude on CVP waveform
A wave = atrial contraction, so if the amp ↑, means atrium is emptying against a high resistance..
it’s either stenotic tricuspid valve or ↓ compliance RV.
Basically, how hard does the atrium have to squeeze..
- tricuspid stenosis
- diastolic dysfunction
- myocardial ischemia
- chronic lung disease → RV hypertrophy
- AV dissociation
- junctional
- V pacing, asynchronous
- PVCs
Loss of A wave on CVP waveform
A fib, v-pacing IF the underlying rhythm is asystole
Reasons for large V wave on CVP waveform
- tricuspid regurg would be main one
- acute ↑ intravascular volume
- RV papillary muscle ischemia
PAOP or PCWP waveform
Akin to CVP of left heart
A wave = LA contraction
C wave = MV elevation into LA during LV contraction (isovolumetric contraction)
V wave = passive left atrial filling
Conditions in which PAOP/PCWP overestimates LVEDP
- Impaired LV compliance (diastolic dysfunction)
- MV disease (either stenosis or regurg)
- L → R shunt
- PPV, PEEP
- COPD
- pulmonary HTN
- PAC placed in wrong zone (not zone 3)
Factors that cause underestimation of CO with thermodilution PA cath measurement
-Injectate too much or too cold
Factors that cause overestimation of CO with thermodilution PA cath measurement
Injectate volume too low, too warm, partially wedged PAC, thrombus on PAC tip
Causes of ↑ Sv02
↓ 02 consumption: A0X application, hypothermia, cyanide (SNP)
↑ 02 delivery: ↑ Pa02, ↑ CO, ↑ Hgb
Sepsis, L → R shunt
→ of ↓ Sv02
↑ 02 consumption: AoX removal, stress, pain, thyroid storm, shivering, fever
↓ 02 delivery: ↓ Pa02, ↓ Hgb, ↓ CO
Cerebral oximetry
- uses NIRS (near infrared spectroscopy)
- measures venous 02 sat
- it only measures regional, NOT global oxygenation
Classification of EEG (highest to lowest)
Beta (awake, induction) Alpha (sleepy) Theta (GA) Delta (GA, deep sleep, brain injury) Burst suppression (GA, CPB, hypothermia, ischemia) Isoelectricity (super deep GA, death)
Hypokalemia EKG
Hyperkalemia EKG
Hyper: narrow peaked T, short QT, wide QRS, wide PR, nodal block
Hypo: U wave, ST depression, flat T wave, long QT
Hypocalcemia EKG
Hypercalcemia EKG
Hypercalcemia: short QT
Hypocalcemia: long QT
What direction does the heart depolarize in?
What direction does it repolarize in?
Depolarizes base → apex and endocardium → epicardium
Repolarizes apex → base, epicardium → endocardium
Which leads do you examine to determine axis deviation
Lead I and avF:
If they are Reaching toward each other (I pointing down and avF pointing up) you have R axis deviation
If they are Leaving each other (I pointing up and avF pointing down) you have L axis deviation
→ of R axis deviation
COPD, acute bronchospasm, cor pulmonale, pulm HTN, PE
→ of L axis deviation
Chronic HTN
LBBB
AS, AI, MR
EKG findings of Brugada syndrome
RBBB, ST segment elevation in precordial leads
Most common in males from Southeast Asia
May require ICD or pad placement during surgery
Common cause of sudden nocturnal death d/t vtach/vfib, sodium ion channelopathy
Difference between second degree HBs
2nd degree Mobitz type I: longer, longer drop Wenkebach (PR interval will gradually increase)
2nd degree Mobitz type II: if some Ps don’t get through you have a type 2 (if the P is there, the PR interval is consistent across the strip)
Metabolic disturbances that can ↑ QT
Hypokalemia, hypocalcemia, hypomagnesemia
Most common, flexible mode of pacemaker
Dual chamber AV sequential demand
DDD
Improves AV synchrony by making sure atrium contracts first then ventricle
Modes of asynchronous pacing
AOO, VOO, DOO
- pacemaker delivers a constant rate, no sensing or inhibition, can be a competitive underlying rhythm
- pacer spike during ventricular repolarization can cause “R on T’ phenomenon
What does the magnet do?
Pacemaker: usually but not always converts pacemaker to asynchronous mode
ICD: suspends ICD and prevents shock delivery
Pacemaker + ICD: shock disabled
What can measure regional cerebral blood flow?
Transcranial Doppler (measures flow velocity) Cerebral oximeter
Jugular oximetry is the only global cerebral monitor and it is invasive
