OSCE Flashcards
What shows normal axis on an EKG?
Positive QRS in lead I and AVF
How can you tell there is right axis deviation?
If QRS is negative in lead I
How can you tell there left left axis deviation?
QRS positive in lead I and negative in AVF
How can you tell RV hypertrophy on Ekg.
R wave greater than S in V1, but gets progressively smaller from V1-6
S wave persists in V5 and 6
How can you tell LVH on EKG?
S wave in V1 + R wave in V5 is greater than 35 mm
What is a significant Q wave?
Greater than 1 mm (one small square/0.04 sec)
1/3 of the height of the complex
What is a normal PR interval?
0.2 sec (one large square, 5 small)
What is stroke volume on the arterial wave form?
Area under the curve from systole to dicrotic notch
What conditions have to be met for PPV to be accurate?
Mechanical ventilation
Closed chest
NSR
What is different about the radial arterial waveform as compared to the proximal aorta?
Steeper slope Wider pulse pressure Blunted and delayed dicrotic notch Lower MAP Lower diastolic peak
How is PPV calculated?
Ppmax-Ppmin/ Pmean X 100
How are SVV and PPV indicative of a patient’s volume status?
Because positive intrathoracic pressure induced cyclic fluctuations in SV and Pulse pressure.
During initial phase of a positive pressure breath, blood is squeezed from pulm vein into the LV increasing its preload and thereby SV and PP. But RV filling is inhibited and RV afterload is increased resulting in a following decrease in LV preload.
What is the a wave on a CVP waveform?
Atrial contraction
What does a canon a wave suggest?
AV dissociation
What is the c wave on CVP waveform?
Tricuspid bulging into the RA due RV isotope if contraction
What is the X descent in a CVP waveform?
Descent of the tricuspid valve into the RV
What does it mean if the X descent is large?
Pericardial tamponade
What is the y descent?
Atrial emptying into the RV
What is the v wave?
Venous return to RA
What is a normal pulmonary artery pressure?
15-30/8-15
What is a normal PAOP?
6-12
What is a normal mean PAP?
Less than 25 at rest
Less than 30 during exercise
What is normal cardiac output?
4-8 L/ min
What is mixed venous oxygen saturation?
SvO2, 75%
VO2/CO X Hb X 1.34
Percentage of oxygen bound to hemoglobin in blood returning to the right heart
What is VO2?
Oxygen consumption
Delivered oxygen - returned oxygen
1.34(CO)(Hgb)(10) (arterial O2% - mvO2%)
What is a normal mixed venous oxygen saturation?
60-80%
What is a normal oxygen partial pressure in the venous blood?
40
What is a normal PvO2 with supplemental oxygen?
Greater than 60
