hemodynamics Flashcards
What is normal Intracranial pressure (ICP)
0-15 mmHg
What is cerebral blood flow
the amount of blood that flows through the brain. 15% of resting cardiac output.
1000L/24 hrs
Contraindications for ICP monitoring
-CNS infection
-coagulations defect
-coagulopathy
-scalp infection
-severe midline shift with ventricular displacement.
-cerebral edema resulting in ventricular collapse
What are the indication for ICP monitoring
-severe TBI
-intracranial hemorrhage
-cerebral edema
-post craniotomy
-space-occupying lesion
-Reye syndrome
-encephalopathy
-meningitis/encephalitis
-GCS of less than 8 or positive CT
What is cerebral perfusion pressure
-responsible for the movement of blood through the brain
-is the difference between MAP and ICP
What are the indications for central venous lines
-rapid fluid replacement
-medication administration
-rapid access to central circulation
-invasive monitoring
What are the contraindications for central venous lines
-significant coagulopathy
-local trauma to the site of insertion
-infection at the site of insertion
How to zero a arterial line
1- ensure cable is connected
2-close the stop cock to the pt and open to air
3- press the zero button on the monitor
4- close the stop cock to air and open to pt.
What is the pressure range for central venous lines
normal is 0 to -2 mmHg
critical is 2-6 mmHg
What is the phlebostatic axis for arterial lines
4th intercostal space mid chest position.
What is the Allen test
-hand above head with a clenched fist and the radial and ulnar arteries compressed.
-hand is then lowered and the fist is opened. pressure remains on the radial artery but released on the ulnar artery. color should return to hand
What are the contraindications for arterial lines
-ischemia of the extremity
-infection at the puncture site
-Raynaud’s disease
-prior vascular operation in the area of the insertion site.
what are the indications for arterial lines
-any patient in shock, who isn’t rapidly responding to therapy.
-pt’s who require constant blood pressure measurements.
what is the difference between ICP and Cushing’s Triad
ICP
-HTN with widening pulse pressure
-tachycardia
-Cheyne-stokes respirations.
Cushing’s Triade
-HTN with widening pulse pressure
-bradycardia– compression of the mid brain.
-Cheyne-stokes respirations.
what does the dicrotic notch indicate
The closure of the Aortic valve and the diastolic phase
What is the anacrotic notch
closure of the pulmonic valve
how much O2 uptake and consumption is there in the body
VO2= 180-280 mL/min
how much O2 is delivered each minute
DO2= 700-1400 ml/min
what is the normal PCWP pressures
8-12 mmHg
what is normal PA pressures
S- 15-25 mmHg
D- 8-15 mmHg
What is normal Rv pressures
S-20-30 mmHg
D- 0-5 mmHg
what is normal CVP pressure
2-6 mmHg
What is normal CI (cardiac index)
2-4 L/min
What is the normal CO.
Q= 4-8 L/min
what is normal SVR pressure
800-1200 dynes/cm2
what is normal MAP pressure
70-100 mmHg
how do you determine coronary perfusion pressure
DBP-PCWP
hemodynamic response to shock
(sepsis)
CVP is low
CI is low
SVR is low
PCWP is low
hemodynamic response to shock
(obstructive)
CVP is high
CI is low
SVR is high
PCWP is high
hemodynamic response to shock
(neurogenic)
CVP is low
CI is normal
SVR is low
PCWP is low
hemodynamic response to shock
(cardiogenic)
CVP is high
CI is low
SVR is high
PCWP is high
hemodynamic response to shock
(hypovolemia)
CVP is low
CI is low
SVR is high
PCWP is low
hemodynamic response to shock
(right ventricle failure)
CVP is high
CI is low
SVR is high
PCWP is low
