Hemodynamics Monitoring Review Flashcards
AANA Standard 9 (A-E)
Monitoring and Alarms.
- Monitor, evaluate and document patient’s physiologic condition as appropriate for procedure and anesthetic technique
- pitch and threshold alarms are turned on and audible
- document BP, HR RR at least every 5 minutes for all anesthetics
-A. O2- Continou monitor oxygen by observation and pulse oximetry. Talk to surgical team regarding fire
B. Ventilation: Continuous monitor ventilation by clinical observations and expired CO2 during moderate sedation, deep sedation or general. Verify intubation of trache by auscultation, chest rise, and expired CO2.
C. Cardiovascular- monitor pt hemodynamics status HR and invasive monitoring as appropriate
D. Thermoregulations: monitor body temp and active measure to facilitate normothermia. When MH triggering agents used, monitor temp and recognize s/s immediately
E. Neuromuscular- when nMB agent administered, monitor response to assess depth of blockade and degree fo recovery
Required Monitors by AANA
EKG, BP, TEMP, PULSE OX, ETCO2
Cornerstone monitoring:
Physical assessment. I.e.:
- Inspection, auscultation, palpation
- Chest rise/fall
- Auscultate breath sounds preop, after intubation, and when ventilators parameters change
- Direct palpating of pulse when monitored value questioned.
- Direct observation beating heart in cardiac six
- Inspection of mucous membrane, skin color and turf or
- Inspect six field for blood loss. UOP observation
- Evalute JVD
- pupillary response
Precocial or Esophageal stethoscope
Minimally invasive, cost effective and continuous monitor
- Continual assessment breath and heart sounds
- sensitive monitor for broncospasm, airway obstruction and changes in hr/rhythm
- High detection for venous air embolism
Speed EKG paper
25 mm/sec
1 SQUARE horizaontal on EKG
1 SQUARE= 0.4 sec. 0.5 cm = 0.20 seconds long
1mm or 0.1 mV high
EKG purpose
Detect arrhythmia Monitor HR Detect ischemia Detect electrolyte changes Monitor pacemaker function
3 lead EKG
RA, LA, LL leADS I, II, III. No ANTERIOR view of heart, Only rhythm monitor
Lead I
RA TO LA
Lead II
RA TO LL
Lead III
La to LL
5 lead EKG
RA, LA, RL, Chest lead 7 views of heart. V1 preferred for arrhythmia monitoring
AVF
Center to LL
AVR
CENTER TO RA
AVL
CENTER TO LA
V1
4TH Intercostal space to right of sternum (septal view of hear)
V2
4th intercostal space to left of sternum (septal view of heart)
V3
Directly b/w V2 and V4(anterior view of heart)
V4
5th intercostal space and L midclavicular line (anterior view of heart)
V5
Level with V4 at left anterior ancillary line (lateral view of heart
V6
LEVEL with V5 at L midaxillary line (lateral view of heart)
5 principle indicators of Ischemia detection
1) ST segment elevation >= 1mm
2) T wave flattening or inversion
3) development of Q waves
4) ST segment depression, flat or downslope >1mm
5) PEAKED T waves
6) Arrhythmias
Inferior Wall ischemia. Which vessel, which leads?
RCA. Change in II, III, avf
Lateral wall ischemia. Which vessel/leads?
Circumflex branch of LCA,. I, AVL, V5-V6
Anterior wall ischemia
LCA, V3-V4
Septal ischemia
Left descending coronary artery (LAD) V1, V2
Normal PR
0.12-0.2 SEC
QRS
0.08-0.10 sec
QT
0.4-0.43 sec
RR interval
0.6-1sec
Blood pressure based on what law?
Ohm’s Law. V=IR. V=blood pressure. Blood flows x resistance
Systolic BP
Peak pressure generated with changes in systolic ventricular contractions. Changes reflect myocardial o2 requirements
Diastolic BP
Trough pressure during diastolic ventricular relaxation. Changes in DBP reflect coronary perfusion pressure
Pulse pressures
SBP-DBP
MAP
Weighted average of arterial pressure during pulse cycle. MAP = SBP + 2(DBP)/3 OR MAP DP+(1/3) (SP-DP)
Palpation non-invasive blood pressure measurement
Palpating return of arterial pulse when occluded cuff is deflated. Underestimates Sys pressure. Only measures SBP
Doppler BP
Based on shift in frequency of sound waves. Only measure SBP
Auscultation
Using sphygmomanometer, cuff and stethoscope. Listening to Kortokoff sounds d/t turbulent flow. Estimation of SBP and DMP
Oscillometry
Senses oscillations/fluctuations in cuff pressure produced by arterial pulsations when deflating BP cuff. 1st oscillation is SBP. Last is DBP. Automated cuffs work this way.Derives MAP, SBP, DBP by algorithm
SBP and DBP algorithm vary by manufacturer.
Less reliable than values for MAP
Oscillometry methods often underestimate systolic an overestimate diastolic significantly reducing PP calculations
How should the NIBP Cuff fit?
Width is 40% circumference of extremity. Length should encircle 80% extremity
Applied snugly, with bladder centered on artery and residual air removed
Falsely high BP MEASUREMENT caused by…
- Cuff too small,
- too loose,
- extremity below level of heart.
- Arterial stiffness- HTN, PVD
Falsely low BP
- Cuff too large
- Extremity above level of heart
- Poor tissue perfusion
- Too quick deflation
Erroneous BP measurements with
Dysrhythmia, tremor/shivering
Complications of NIBP measurement
=Pain -Petechia and ecchymoses -limb edema -venous stasis - peripheral neuropathy - compartment syndrome —- pt with peripheral neuropathy, arterial or venous insufficiency, severe coagulopathies or recent use thrombolytics more prone to complications
What does arterial line measure?
Systemic arterial pressure waveform from ejection of blood from LV into aorta during systole, with peripheral runoff during diastole
Transducer to convert generated pressure into electiv signal to provide a waveform
Complications Risk of Arterial line
Overall low risk. Increased risk: - vasospastic arterial dx - previous arterial injury -thrombocytes is -protracted shock -high dose vasopressin administration - prolonged cannulation -infection
Allen tat
Occlude both radial and ulnar arteries, have pt make tight fist. Then have patient open hand, release ulnar artery and watch for color to return to palm with radial artery occluded
Indications for a line
- elective and deliberate hypotension
- wide swings intra op BP
- risk of rapid BP changes
- rapid fluid shifts
- titration vasoactives
- end organ dx
- repeated blood sampling
- failure of indirect BP measurement
Zeroing a line transducer
Phlebostatic axis at 4th intercostal space mid axillary line.
What will Aline reading be if transducer is high/low
High transducer= low readings
Low transducer= high reading
20 cm diff makes 15 mmHg difference in arterial line
As arterial line location changes…
Further away from heart, more defined systolic peak. Diacritic notch is further out on downslope
What to check for with Overdamped
Looks connections Air bubbles Kinks Blood blots Arterial spasm Narrow tubing
Overdamped wave form will appear flat
What to check/look for if Underdamped
Will show peaked wave with whip Catheter whip or artifact Stiff non-compliant tubing Hypothermia Tachycardia/dysrhythmia
Square wave test
2 oscillations only before normal waveform
Aline complications
Distal ischemia, psuedoaneuysm Hemorrhage Arterial mobilization Infection Peripheral neuropathy Misuse of equipment
Nerve damage Thrombosis Air embolus Skin necrosis Loss of digits Vasopasm Retained guide wire
ASA closed claims 54% r/t radial artery (ischemic injury, radial nerve or retained wire fragment) others were related to femoral artery (thrombotic/hemorrhagic events)
Aortic stenosis shows as what on a line?
Slow upstroke (pulsus tardus) and narrow pulse pressure (pulsus parvus)
Aortic regurgitation shows as what on a line?
Double peak (biferiens pulse) with wide PP
Hypertrophic CMP on Aline?
Spike and dome
Pulsus alternans
Alternating pulse pressure amplitude. Seen in sys lV failure
Pulsus paradoxes
Seen in cardiac tamponade. Exaggerated decreases in sys BP with inspiration
Type of law pulse oximeter uses?
Beer- Lambert Law
Wavelength of pulse ox?
660 (unoxygenated) and 940 nm (oxygenated)
When in pulse ox inaccurate?
Malposition of probe Dark nail polish Different hemoglobin Dyes Electrical interference Shivering
Ocyhemoglobin dissociation curve
Affinity of o2 to hgb
Left shift
Wants to hold onto o2 (Alkalosis, hypocardbia, hypothermia,
Right shift
Let’s go of o2 readily. Acidosis, hypercarbia, hyperthermia
CVC indications
CVP monitoring PA monitoring Transvenous cardiac pacing Temporary HD Drug admin of chemo, vasopressors, hyperalimentation. Prolonged abs Rapid infusion of fluids Aspiration of air emboli
Basic nursing care
Blood sampling
Diagnostic measurements
PACING
Preferred site for cvc
RIGHT IJ
Where should CVC be?
Ideally, tip just within SVC, just above junction of VC and RA, parallel to vessel walls
Inferior border of clavicle, above level of 3rd rib. T4/T5 interspace. Carina
Contraindications of CVC
R atrial tumor
Contralateral pneumothorax
Infection at site
Complications of CVP monitoring
Mechanical injury (vascular injury , arterial and venous, CARDIAC TAMPONADE) Respiratory compromise (airway compression, pneumonia) Nerve injury Arrhythmia Thromboembolic (PE, VT) Infection Misinterpretation of data RETAINED GUIDEWIRE
Captain CV
Normal CVP in awake, breathing
2-7 mmHg
Normal CVP with mechanical ventilation
Rises 3-5 mmHg
5-12 normal
CVP waveform peaks?
A,c,v
CVP waveform descents?
X,y
Cardiac cycle phases
Atrial contraction Isovolumetric contraction Ventricular ejection Isovolumetric relaxation Ventricular filling
“A” wave on CVP
- Caused by atrial contraction. -Follows p wave on EKG.
- At end diastole.
- Corresponds with atrial kick and causes filling of RV
“C” wave CVP
- Due to isovolumetric contraction (right side) which causes closing of tricuspid valve and bulges back into right atrium.
- Occurs in early systole
“X” descent in cvp
- Systolic decrease in atrial pressure due to atrial relaxation
- Mid-systolic event
“V” wave in CVP
- Ventricular ejection which drives venous filling of atrium.
- Late systole with triscupid valve CLOSED
- Occurs just after t wave in EKG
Y Descent in CVP
Diastolic decrease in atrial pressure due to flow across open tricuspid valve
-early diastole
Size of pA cath
7 for. 110 cm in length with 4 lumens
Indications of PA cath
- LV Dysfunction
- valvular dx
- plum htn
- CAD
- ARDS
- Shock/sepsis
- ARF
- Sx procedures
PA cath complication
-Arrhythmia (vfib, RBBB, CHB) Catheter knotting Balloon rupture Pneumonia Pa rupture Infection Damage to cardiac structures
Normal vena cava distance with PA
15
RA distance with PA
15-25
RV distance
25-35
PA distance
35-45
Wedged PA distance
40-50
How do PA wedge waveform compare to CVP?
More damping through pulmonary system so less distinct waveforms., Events come much later. (Line up with t wave more or less)
PCWP waveform a wave
Contraction of left atrium. Small deflection unless resistance to blood moving as with mitral stenosis
PCWP C waveform
Due to rapid ris in LV pressure in early systole. Mitral valve bulges into LA
PCWP v waveform
Blood enters LA during late systolie
Prominent v wave on PCWP
Shows mitral insufficiency d/t large blood going back into LA DURING SYSOTLE
SV normal
60-90
SVR normal
800-1200 dynes, 10-20 wood units
PVR normal
0.5-3
MVO2
70-80
Co NORMAL
4-6.5
SBP NORMAL
90-140
DBP normal
60-90
MAP normal
70-105
Systolic pressure variation
5
PPV
10-13%
RV PRESSURE
15-30/8
PA pressure
15-30/5-15
Mean PA pressure
9-20
PCWP normal
6-12
LA Pressure
4-12
SPO2
95-100
Co
4-8 L/MIN
CI
2.4-4 L/MIN/M2
Peak inspiratory pressure normal
15-20
TV normal
6-8 mL/kg of IBW
ETCO2 normal
35-40 mmHg
ICP normal
5-15 mmhg
BIS normal (awake)
80-100
What is standardized gain on EKG?
1mV= 10 mm calibration
Therefore 1 mm ST segment change is accurately assessed
How does oscillometry BP work?
Senses oscillations/fluctuations in cuff pressure
1st oscillation correlates with SBP
MAXIMAL degree of detectable pulse is the mAP
Oscillations cease at DBP
With oscillometry methods underestimate systolic and overestimate diastolic
Underestimate mean values during HTN
Overestimate mean during hypotension
How long do you want to see color return in the Allen test?
6-10 seconds
4 ways of NIBP (General)
Palpation
Doppler
Auscultation
Oscillometry
How can you improve system dynamics and accuracy with arterial line?
Minimize tube length Limit stop cocks No air bubbles Mass of fluid small Use non compliant, stiff tubing
When does the systolic upstroke of the arterial line start?
180 seconds after R wave.
What happens during interval b/w r wave and upstroke of arterial line?
Depolarization of ventricular myocardium
Isovolumetric left ventricular contraction
Opening of aortic valve
Left ventricular ejection
Propagation of aortic pressure wave
Transmission of the signal to pressure transducer.
What are the actions for damped waveforms on Aline?
Pressure bag inflated to 300 mmHg Reposition extremity or patient Verify appropriate scale Flush or aspirate line Check or replace module or cable
Talk about pulse pressure variation
PPV is calculated as diff between maximal PPmax and PPmin pulse pressure during single respiratory cycle, divided by average of these two values
PPmax 150-70= 80
PPmin 120-60= 60
PPV= PPmax-PPmin/((PPmax+PPmin)/2)
(80-60)/((80+60)/2)= 29%
Normal 9-13% >13% needs fluids <9% should not receive intravascular expansion if 9-13, uncertain if volume would be helpful or not
In order to measure PPV accurately: TV 8-10mL/kg, PEEP >5, regular cardiac rhythm, normal intraabdominal presure, closed chest
What happens with blood flow in heart during positive pressure ventilation?
Increase in lung volume compresses lung tissues, displaces blood within pulmonary venous reservoir into left heart chambers, this increases LV PRELOAD. Increase in intrathoracic pressure also decreases after load.
This increase in LV preload and LV afterload, produces an increase in LV SV, increase in CO, and arterial pressure.
What does ASA/AANA standards for basic monitoring require for pulse ox?
Variable Pitch tone must be audible when in use
What is the relationship between Sao2 AND pao2?
SaO2 is function of PaO2. The relationship b/w the two is described by O2Hb dissociation curve.
Curve is not linear, which means Sao2 CANNOT discriminate between normoxic and hyperoxic conditions.
SPO2 accuracy is reduced at values Lower than 70-75%
What is the gold standard for SaO2 measurements when pulse ox inaccurate/unobtainable?
Co-oximetry
Explain why the LIJ site is not preferred for CVC
- Cupola of pleura is high on left, increasing risk fo pneumothorax
- Thoracic duct might be injured during procedure as it enters venous system at junction of LIG and SCL vein
- LIJ is often smaller than right
- Injury might incur on right lateral walll of suprerior vena cava as the catheter transverse the left brachiocephalic vein and enter the SVC perpendicularly
How much blood remains in ventricle after ventricular systole?
50-60mL of blood or ESV (end systolic volume)
Size of pa Cather? Lumens?
7 French (introducer is 8.5 for) 110 cm length marked at 10 cm
4 lumens -distal port PAP Second port 30 cm more proximal to CVP 3rd lumen balloon 4th wires for temp thermistor
Size of CVC catheter?
7 French, 20 cm length
Uses of TEE in OR
Unusual causes of acute hypotension Pericardial tamponade Pulmonary embolism Aortic dissection Myocardial ischemia Valvular dysfunction Valvular function Wall motion
7 cardiac parameters observed
1) Ventricular wall characteristics and motion
2) Valve structure and function
3) Estimation of end-diastolic and end-systolic pressure and volumes
4) CO
5) Blood flow characteristics
6) Intracardiac air
7) Intracardiac masses
Complications TEE
Esophageal trauma
Dysrhythmia
Hoarseness
Dysphagia
Types of cardiac output monitoring
Thermodilution Continuous thermodilution Mixed venous oximetry Ultrasound Pulse contour
Arterial oxygen content
16-20. Normal 18
Tell me about pulse ox
Method of measuring hemoglobin oxygen saturation (SPO2)
- Non invasive
- Measures transmission of light through a solution to the concentration of the solut in the solution (application of beer lambert law)
-Uses wavelengths of 660 (unoxygenated) and 940 (oxygenated)
Pulse oximeter is composed of light emitters and a photodectector
Use- hypoxemia and detection of perfusion
Effect of methylene blue on SPO2 relative to Sao2?
Decrease
Carboxyhemoglobinemia will do what to SPO2?
Increase
Methemoglobinemia will do what to SPO2
Constantly reads 85%
