monitoring devices - lab values Flashcards
week 6
electrogardiogram
graphic depiction of hearts electrical current and function
- picks up any electrical activity; not specific
abnormal arrythmias can sound the alarm
- PT’s should not silence the alarm w/out first determining cause
inaccurate reads on pulse oximetry are common with:
- anemia
- arrythmia
- decreased CO
- vascoconstriction (cold fingers)
- nail polish
-motion articfact
for those with COPD on supplemental O2 what is a common goal for SpO2 range
88%-92% SpO2 at rest and with activity
- titration of supplemental O2 will be provided to maintain these parameters
supplemental O2
what are the 3 cylinder types?
D
E
M
supplemental O2
how long will the tank last?
D?
E?
M?
D = 350 liters of O2 (constant = 0.16)
E = 625 liters of O2 (constant = 0.28)
M = 3,000 liters of O2 (constant = 1.56)
safe residual pressure - 200 psi
supplemental O2
what is the formula to calculate how long a tank will last
(psi in the tank - safe residual pressure) x C / flow rate in liters per minute (LPM)
example: your E cylinder tank has 900 psi remaining. the nasal cannula is set to recieve 3L of supp O2. how long will it last?
(900psi -200) x 0.28 / 3L/min = ~65 minutes
invasive monitoring
arterial line
- necessary for intra arterial monitoring that is continous (could bp or mean arterial pressure)
- typically used whe nperipheral arterial system is impaired
- could also be used in korktkoff sounds are difficult to hear
primary site: radial artery
invasive monitoring
what detects average arterial wall pressure and tissue perfusion to vital organs
MAP
- speak with MD if MAP is < 65mmHg (normal= 70-110 mmHg)
invasive monitoring
central line
- venous access via subclavian, jugular, or femoral vein
- threaded through right side of heart, resting within right atrium or pulmonary artery
invasive monitoring
central line
tunneled vs non tunneled
tunneled = longer duration (peripherally inserted central catheter - PICC)
non-tunneled = shorter duration (swan-gaz catheter/pulmonary A. catheter)
invasive monitoring
central line - bc of location, can directly measure the following:
- R atrial pressure (central catheter line)
- pulmonary artery pressure (swan ganz)
- pulmonary capillary wedge pressure (swan ganz)
invasive monitoring
central line - bc of location, can indirectly mesure the following:
- left atrial pressure (swan ganz)
- left ventricular end diastolic pressure (swan ganz)
mixed venous oxygen saturation is obtained from?
swan ganz catheter
what is venous oxygen reserve (SvO2)?
the (low) amount of O2 returning to the heart after capillary interaction
SvO2 = % of residual O2 binding to hemoglobin after tissue extration of O2
normal = 60-80%
what happens when mixed venous oxygen saturation is too low?
too low = tissue is extracting too musch O2 (high demand for O2) –> increased oxygen demand, hypoexmia
what happens when mixed venous oxygen saturation is too high?
too high = tissue is not using enough oxygen (low demand for O2)
* sepsis - blood infection that can damage vital organs –> life threatening
what is continous positive airway pressure (CPAP)
- non invasive positive-pressure ventilation that is continuous and predetermined
- components include a face mask, hose and flow generator
- PT’s need to speak with nursing prior to treatment
if pt is labored or anxious, typically will hold on therapy
treatment for obstructive sleep apnea
What is a biventricjular positive airway pressure (BiPAP)?
Bi = 2 = two levels of pressure
- inspiratory (IPAP) - high pressure
- expiratory (EPAP) - low pressure
nasal cannula (NC)
- most common
- maxes out at 6 L
- limited FiO2
- no humidifier
NC with oximyzer
NC =nasal cannula
- contains reservoir
- collects oxygen during exhale
- recirculates at next inhale
- higher O2 concentration w/ each breath
high flow nasal cannula - green
- can deliver up to 15 L
higher FiO2
can still eat/drink/talk
simple mask for non invasive oxygen delivery
great for mouth breathers
- can deliver 5-10 L
what type of oxygen mask is ideal for pt w/ COPD who ahs a low to moderate oxygen requirement but is at risk for hypercarbia (hypercapnia) too much oxygen?
venturi mask
- imports room air through a side port and doing so increases blood flow of gas
2-15 L (depending on diluter)
how much liters of O2 can aerosol mask deliver?
what pt’s would be seen wearing this?
10-12 L
