ASA Standards
- qualified personnel
- oxygenation: SaO2, FiO2
- ventilation: ETCO2, stethoscope, disconnect alarm
- circulation: BP, pulse, ecg
complications of A-line
vasospastic dz, prolonged shock, high-dose vasopressors, prolonged cannulation
as you go up the arm more proximally, the biggest risk of complications is
thrombosis (embolic or occlusive dz)
2 advantages of fem a-line
assessment of central arterial pressure and appropriate access should placement of IABP become necessary during the surgical procedure
Systolic pressure variation measures what
diff between maximal and minimal values of systolic BP during PPV
what is a normal SPV
5 mmHg
an SPV of 15mmHg suggests what
hypovolemia
CVP wave abnormalities
[still need to look up]
where is the IJ vein located in terms of muscles
lies in groove between sternal and clavicular heads of sternocleidomastoid muscle
what kind of ekg abnormalities can central line insertion cause
PVC’s, VT
what kind of ekg abnormalities can central line insertion cause
PVC’s, VT
which subclavian should you try first and why
left. even though risk of thoracic duct, right side acute angle is difficult.
which CVC site has great risk for vascular avulsion
EJ
what are the complications of double cannulation of the same vein
vein avulsion (most common), catheter entanglement, catheter fracture.
why shouldn’t you cannulate both sides of the neck
limits venous drainage
CVP reflects pressure at
junction of vena cava and RA
CVP provides estimate of what two things
intravascular blood volume and RV preload
CVP should be measured at
end-expiration
CVP is zeroed at
mid-axillary line
PA catheter- how do you know youre in the RV
spike in systolic pressure
PA catheter - how do you know youre in the PA
spike in diastolic pressure
if patient has a preexisting LBBB and you put in a swan, you should also do what
externally pace
what is the most common complication of PA cath insertion
arrhythmia
in what condition does PAOP underestimate LVEDV
aortic insufficiency
in what conditions does PAOP overestimate LVEDP (and by extension LVEDV)
impaired LV compliance (ischemia)
mitral valve dz (stenosis or regurg)
L->R shunt tachycardia PPV PEEP COPD Pulm htn non west zone III placement of PAC
Thermodilution technique
inject fixed volume, 10ml of room temp or iced D5W) into CVP port at end-expiration and measure resulting change in blood temp at distal thermistor
CO relationship to area under the curve
indirectly proportional
what makes CO measurements inaccurate
variations in respiration (use avg of 3 measures)
blood clot over thermistor tip: inaccurate temp
shunts: LV + RV outputs unequal, CO invalid
TR: recirculation of thermal signal, CO invalid
computation constants : varies for each OAC
If what two things remain constant, SVO2 is indirect indicator of CO
O2 sat, VO2+Hg (sat and delivery)
how can we measure CO
swan or CVP, or blood gas from PA/CVP
normal SvO2 value
65%
What is the most common reason for an elevated mixed venous sat?
over wedged or advanced PA cath….. think because it is further into the pulm circulation so higher O2 content.
what are the 2 broad things that cause an increase in SVO2
hyper oxygenated state or inability to extract oxygen
an increased SVO2 is what percentage
> 75%
high cardiac output (sepsis, burns, L–>R shunt, AV fistulas) causes an increase or decrease in svO2?
increase
carbon monoxide causes a high or low SVO2
high
SVO2 varies directly with
SaO2, Hg, CO
SVO2 varies indirectly with
VO2 (consumption)
bleeding/shock causes high or low SVO2?
low
fever, agitation, thyrotoxic, shivering causes high or low SVO2
low
MI, CHF, hypovolemia causes high or low SVO2
low (think decreased CO)
hypothermia causes high or low SVO2
high (think decreased demand)
general anesthesia causes high or low SVO2
high (think decreased demand)
NMB causes high or low SVO2
high (think decreased demand)
sepsis causes high or low SVO2
high (think high cardiac output)
burns causes high or low SVO2
high (high cardiac output)
left to right shunt causes high or low SVO2
high (high cardiac output)
in patients with CAD what are the best leads for detecting myocardial ischemia
II and V5
an under dampened system will ___estimate systolic BP and ___diastolic BP
overestimate systolic, underestimate diastolic
an over dampened system will not oscillate at all but will settle to baseline slowly, thus ____ systolic and ____ diastolic pressures.
underestimating systolic and overestimating diastolic
advantage of brachial A-line found by cleveland clinic
the elimination of the pressure discrepancy seen with radial a-lines in the immediate post bypass period
what two things cause a narrow pulse pressure on the arterial waveform
pericardial tamponade and hypovolemia
increase in pulse pressure may be a sign of
worsening aortic valvular insufficiency or mild hypovolemia
a dicrotic notch appearing high on the downslope of the pressure trace suggests ____ vascular resistance
high
highest rate of pneumothorax is with which approach
subclavian
what causes most pressure monitoring errors?
air within a catheter or transducer
T/F ? the radial artery pressure may be significantly lower than the aortic pressure at the completion of CPB and for 5-30 min following CPB
true
what is the current consensus on benefit of PAC
placement may have benefit in high-risk patients, or those with special indications. however, in routine CABG patients, the PAC has little, if any, benefit.
T/F: in cardiac surgical patients with ascending aortic atheroma identified by epiaortic scanning, modification of the surgical technique and neuroprotective strategies have been reported to reduce the incidence of neurologic complications from ~60% to 0%
true
t/f: though low serum calcium may affect myocardial pumping function, admin of ca during potential neural ischemia or repercussion may likely worsen the outcome and should be avoided
T
