Midterm Flashcards
Arterial cannulation is indicated for all of the following except:
a. determining cardiac output.
b. severe hypotension.
c. unstable respiratory failure.
d. avoiding arterial injury from multiple arterial punctures.
determining cardiac output
When vasodilators such as sodium nitroprusside are administered, it is important to monitor the fall in blood pressure because low blood pressure can:
a. cause arterial spasm.
b. cause a stroke in obese adult patients.
c. decrease blood flow to the coronary arteries.
d. increase the likelihood that pulmonary edema may develop.
decrease blood flow to the coronary arteries
The pulse pressure is important hemodynamically because it is an indication of:
a. central venous pressure (CVP).
b. mean arterial pressure (MAP).
c. right ventricular stroke volume.
d. left ventricular stroke volume.
left ventricular stroke volume
What will the MAP be if the systolic blood pressure is 140 mm Hg and the diastolic blood pressure is 80 mm Hg?
a. 60 mm Hg
b. 100 mm Hg
c. 110 mm Hg
d. 120 mm Hg
100 mmHg
MAP = 2(Diastolic)+Systolic/3
When the water manometer is used to measure the CVP, the reading usually is taken at:
a. peak inspiration with the patient in the semi-Fowler position.
b. the end of expiration with the patient in the supine position.
c. the end of inspiration with the head of the bed elevated 45 degrees.
d. any time during inspiration or expiration with the head of the bed elevated 45 degrees.
the end of expiration with the patient in the supine position
Complications involving the use of CVP catheters include all of the following except:
a. Bleeding.
b. Pneumothorax.
c. Infection.
d. Atrial septal puncture.
atrial septal puncture
The pulmonary artery catheter allows assessment of:
a. the left ventricular preload.
b. the mixed venous oxygen saturation (SvO2).
c. the cardiac output.
d. all of the above.
all of the above
When the pulmonary artery catheter is inserted, the balloon is inflated in the right atrium before it is inserted further. This is done to:
a. allow the catheter to float.
b. decrease the risk of premature ventricular contractions.
c. allow the catheter to enter the right ventricle more easily.
d. all of the above.
all the catheter to float
With a properly inserted and positioned pulmonary artery catheter, a systolic pressure reading in the pulmonary artery of 50 mm Hg could be due to:
a. pulmonary vasodilation
b. tricuspid valve stenosis
c. pulmonic valve stenosis
d. chronic obstructive pulmonary disease (COPD)
chronic obstructive pulmonary disease (COPD)
An increase in pulmonary artery systolic pressure is seen in patients with all of the following conditions except:
a. pulmonary embolus
b. mitral valve stenosis
c. right ventricular failure
d. hypoxia and hypoxemia
right ventricular failure
The amount of blood pumped out of the left ventricle in 1 minute is the definition of:
a. afterload
b. cardiac output
c. stroke volume
d. ejection fraction
cardiac output
Cardiac output is a product of which two variables?
a. Heart rate and stroke volume
b. Heart rate and body surface area
c. Cardiac index and blood pressure
d. Stroke volume and ejection fraction
heart rate and stroke volume
To standardize the measurement of cardiac output in individuals of different sizes, the value for cardiac output is divided by the person’s body surface area. The result is known as:
a. cardiac work.
b. the cardiac index.
c. the standardized cardiac output.
d. the cardiac end-systolic volume
cardiac index
The filling pressure of the left heart also is known as the _____ pressure.
a. starling
b. central venous
c. ventricular filling
d. pulmonary capillary wedge
pulmonary capillary wedge
Which of the following is used to determine the afterload of the right ventricle?
a. cardiac output
b. pulmonary artery pressure
c. pulmonary vascular resistance
d. pulmonary capillary wedge pressure
pulmonary vascular resistance
A drug that increases the contractility of the heart is known as a positive:
a. inotrope
b. dromotrope
c. chromotrope
d. vasoconstrictor
intotrope
Which of the following parameters is the most important in controlling cardiac output in healthy people?
a. pumping ability
b. heart rate
c. conduction rate
d. venous return
venous return
Which of the following pressures is a clinical indicator of ventricular afterload?
a. LVEDP
b. CVP
c. PCWP
d. MAP
MAP
Which of the following mechanisms are responsible for compensating heart failure?
I. Improved contractility
II. Vasoconstriction
III. Fluid retention
IV. Vasodilation
I, II, III
Where is the Swan-Ganz catheter placed if a waveform shows a clear, sharp upstroke on the left, falling to a distinct notch in the downstroke on the right?
a. left atrium
b. right ventricle
c. pulmonary artery
d. right atrium
pulmonary artery
Which of the following pressures is an indicator of afterload?
a. RAP
b. mPAP
c. PCWP
d. CVP
mPAP
Which of the following factors restrict ventricular expansion during diastole?
I. An already overstretched, distended ventricle
II. Pericardial tamponade
III. Myocardial infarction
IV. The increased pressure surrounding the heart during positive pressure mechanical ventilation, especially in the presence of high levels of PEEP
I, II, III, IV
A PCWP of 25 mm Hg and a CI of 1.5 L/min/m2 is consistent with which of the following conditions?
a. left ventricular failure
b. blood volume loss
c. pulmonary edema
d. peripheral hypoperfusion
left ventricular failure
Which pharmacologic agent should be administered to a patient with abnormally low vascular resistance?
a. inotropes
b. IV fluids
c. vasopressors
d. oxygen
vasopressors
The following pressures have been recorded on a patient that has been assigned to you:
CVP 17 mmHg PCWP 5 mmHg PAP 42/38 (mPAP = 39 mmHg) CI 1.7 L/min SVR 1596 dynes.sec.cm-5
Based on these recorded values, where is the problem?
a. hypovolemia
b. lungs
c. left heart
d. right heart
lungs
If the patient presented with the following pressures, what would be the patient’s SVR in dynes.sec.cm-5?
CVP: 1 mmHg PAP: 15/5 mmHg PCWP: 5 mmHg B/P: 93/64 mmHg C.I.: 3.7 L/min C(a-v)O2 7 vol%
a. 9.82 dynes.sec.cm-5
b. 36 dynes.sec.cm-5
c. 785 mmHg/L/min
d. 785 dynes.sec.cm-5
785 dynes.sec.cm-5
SVR = (mPAP - CVP) / CO x 80
In the patient presented in the above question, what is the cause of these pressure changes?
a. cardiogenic shock
b. hypervolemia
c. hypovolemic shock
d. sepsis
sepsis
An unconscious 70 kg patient is brought to the ED by paramedics. Barbituate intoxication is suspected. The patient is immediately intubated and placed on ventilatory support via a transport ventilator. The patient exhibits profound hypotension and large quantities of crystalloid therapy is administered. The patient is transferred to the MICU where she is placed on a PB-980 ventilator at 35% FiO2. It is decided to place a balloon-tipped flow-directed catheter (BTFDC). A CXR is ordered after 8 hours and shows evidence of alveolar and interstitial edema. The following data are obtained with the patient now on an FiO2 of 60% on the A/C mode:
Three hours after the placement and calibration of the BTFDC, the patient has the following values:
PAP 56/41
POWP 22 mmHg
CVP 11 mmHg
C(a-v)O2 4.2 vol%
Based on the above information, which of the following is the MOST likely cause of this patient’s condition? Please EXPAIN your answer.
a. LV failure
b. RV failure
c. Hypervolemia
d. Hypovolemia
LV failure because the PCWP is increased and reflects LV function and perfusion is decreased with C(a-v)O2
A 68 year old male patient is admitted to the MICU after falling at a nursing home. Upon inspection, he is comatose, febrile, has a blood pressure of 60/43. The patient’s appearance suggests protracted poor oral intake. The admission workup shows a fractured right femur with swelling in the pelvic region that is suggestive of a hemorrhage. Because of this, he is scheduled for emergency surgery. In the operating room, profound hypotension continues despite administration of two units of blood and 3 liters of crystalloid. After successful control of bleeding, a BTFDC is placed and the following data is obtained:
PAP 43/26 mmHg
PCWP 2 mmHg
CVP 28 mmHg
CI 1.8 L/min
Based on this information, what is the most likely cause of these hemodynamic values? Please explain.
Calculate this patient’s PVR:
pulmonary embolism because the PAP is increases as well as CVP and the embolism is blocking blood flow from left heart
PVR = 660 dynes.sec.cm-5
PVR = (mPAP - CVP) / CO x 80
A 14 year old girl was admitted with Myasthenia Gravis and pneumonia. She was placed on a mechanical ventilator and an arterial line and Swan Ganz catheter were placed for continuous monitoring of her ABGs and fluid status/management. After 24 hours, the following data were obtained:
CVP 11 mmHg
PAP 53/34 mmHg
PCWP 16 mmHg
C.O. 8.6 L/min
From the choices below, which is the most likely cause of her condition? Please explain your answer.
a. hypervolemia
b. hypovolemia
c. LV failure
d. ARDS
After your explanation, select from the following the goal of therapy for this patient and EXPLAIN your answer.
a. increase preload
b. increase afterload
c. decrease preload
d. decrease afterload
e. increase contractility
hypervolemia because all pressures are increased
decrease preload because it will bring SV down and return CO to normal
define CVP
mean blood pressure in central veins and right atrium
define LAP
mean blood pressure in left atrium
define LVEDP
pressure in left ventricle at end diastole
define mPAP
mean blood pressure in pulmonary capillaries
define PAWP
time averaged pulmonary artery pressure
define pulse pressure
difference in arterial blood pressure between systolic and diastolic
define RAP
mean pressure in right atrium
define afterload
total force opposing ventricular ejection
define preload
myocardial fiber length at end diastole
“filling”
define contractility
force of ventricle contraction independent of preload or afterload
define SV
amount of blood ejected by either ventricle per contraction
define CO
amount of blood pumped by the heart per minute
define CI
cardiac output expressed per body surface
define EF
percentage of ventricular chamber emptying
define oxygen delivery
quantity of oxygen pumped by the heart to body tissue per unit of time
define O2ER
amount of oxygen extracted and consumed by the tissues relative to the amount of oxygen delivered
define PVR
resistance to right ventricular ejection of blood into the pulmonary vasculature
The four main factors which regulate SVR are blood vessel diameter, blood volume, blood viscosity and the kidneys
true or false
true
LV afterload is directly proportional to SVR
true or false
true
Oxygen is a potent vasoconstrictor of the pulmonary vessels
true or false
false
Pulmonary vasodilators act to increase PVR
true or false
false
normal MAP
80 - 100 mmHg
93 mmHg
calculation for MAP
2 (diastolic) + systolic / 3
normal CVP
0-6 mmHg spontaneous
2-6 MV
normal mPAP
10-20 mmHg
calculation for mPAP
2 (diastolic) + systolic / 3
normal PCWP (PWOP/LVEDP)
4-12 mmHg
normal PVR
100-250 dynes.sec.cm-5
100-200 dynes.sec.cm-5
calculation for PVR
(mPAP - PCWP) / CO x 80
normal SVR
900-1400 dynes.sec.cm-5
calculation for SVR
(MAP - CVP) / CO x 80
normal CO
4-8 L/min
calculation for CO
SV x HR
normal CI
2-4 L/min
calculation for CI
CO / BSA
normal EF
60-75%
60%
The work performed by the left ventricle is:
a. Stroke work
b. Cardiac output
c. LV stroke work
d. LV cardiac output
LV stroke volume
The myocardial fiber length at end diastole is:
a. Preload
b. Afterload
c. Contractility
d. Stroke work index
preload
Myocardial O2 supply is determined by:
a. Preload and afterload
b. HR and contractility
c. CaO2 and SV
d. Coronary blood flow and CaO2
coronary blood flow and CaO2
SVR is increased by:
a. Vasoconstriction
b. Vasodilation
c. Increased vessel distensibility
d. None of the above
vasoconstriction
If after an A-line insertion, the distal pulse becomes absent, what should be done?
a. An embolectomy should be performed
b. The catheter should be removed
c. Firm pressure should be applied for 5-10 minutes
d. Watch insertion site for bleeding
the catheter should be removed
CVP catheter and Swan Ganz catheter position may be confirmed by:
a. Catheter length
b. PaO2
c. Pressure waveform
d. X-ray
pressure waveform
The primary cause of a decreased PAP is:
a. L-R shunt
b. Increased PVR
c. Hypovolemia
d. LV failure
hypovolemia
When a PAP waveform suddenly changes from 20 mmHg/0 mmHg to 20 mmHg/10
mmHg, which of the following has most likely occurred:
a. Increased PVR
b. Decreased PVR
c. Catheter tip has slipped into RV
d. Catheter tip has spontaneously wedged
catheter tip has slipped into RV
Pressure waveforms should be measured and recorded at:
a. During inspiration
b. During expiration
c. At end inspiration
d. At end expiration
at end expiration
The 3 most common clinical manifestations that are present with Cor Pulmonale are:
a. Dyspnea, cough, orthopnea
b. Fatigue, anxiety and decreased urinary output
c. JVD, peripheral edema, hepatomegaly
d. SOB, hypoxemia, pallor
JVD, peripheral edema, hepatomegaly
During an MI, cardiogenic shock will likely occur when C.I. (cardiac index) is:
a. < 1.8 L/min
b. < 2.2 L/min
c. < 2.7 L/min
d. < 4.3 L/min
< 1.8 L/min
Pulmonary Edema occurs when colloid osmotic pressure (COP) is:
a. COP > PCWP
b. COP < PCWP
c. COP > CVP
d. COP < CVP
COP < PCWP
The most common originating cause of high pressure pulmonary edema is:
a. Intravascular volume overload
b. Increased pulmonary venous pressure
c. Increased LAP
d. Increased LVEDP
increased LVEDP
The most common cause of cardiogenic shock is:
a. Acute MI
b. Arrhythmias
c. Post-op failure
d. Pulmonary embolism
acute MI
A 45 year old male is three days post-op following repair of a perforated bowel. He is
hypotensive and currently on a PB-980 ventilator. A BTFDC and A-line have been
inserted with the following data recorded: mPAP = 15 mmHg, CVP = 1 mmHg, CO = 9.6
L/min, PvO2 = 48 mmHg and B/P is 80/50 mmHg.
Calculate the patient’s MAP.
2 (diastolic) + systolic / 3
2 (50) = 80 / 3
60 mmHg
A 45 year old male is three days post-op following repair of a perforated bowel. He is
hypotensive and currently on a PB-980 ventilator. A BTFDC and A-line have been
inserted with the following data recorded: mPAP = 15 mmHg, CVP = 1 mmHg, CO = 9.6
L/min, PvO2 = 48 mmHg and B/P is 80/50 mmHg.
Calculate the patient’s SVR
(MAP - CVP) / CO x 80
(60 - 1) / 9.6 x 80
491.67 dynes.sec.cm-5
A 45 year old male is three days post-op following repair of a perforated bowel. He is
hypotensive and currently on a PB-980 ventilator. A BTFDC and A-line have been
inserted with the following data recorded: mPAP = 15 mmHg, CVP = 1 mmHg, CO = 9.6
L/min, PvO2 = 48 mmHg and B/P is 80/50 mmHg.
The data on the previous patient are most consistent with: (EXPLAIN)
a. Hypovolemia
b. Non-cardiogenic pulmonary edema
c. Septic shock
d. Hypervolemia
e. Pulmonary embolus
septic shock
The PAP is within normal range which is
indicative of a normal amount of blood being ejected from the RV with normal PVR.
Also, decreased CVP, increased CO, increased PvO2, decreased MAP, decreased B/P
and decreased SVR indicate Sepsis.
A 45 year old male is three days post-op following repair of a perforated bowel. He is
hypotensive and currently on a PB-980 ventilator. A BTFDC and A-line have been
inserted with the following data recorded: mPAP = 15 mmHg, CVP = 1 mmHg, CO = 9.6
L/min, PvO2 = 48 mmHg and B/P is 80/50 mmHg.
What would be the goal of therapy for the patient? (EXPLAIN)
a. Increased preload
b. Increased afterload
c. Decreased preload
d. Decreased afterload
e. Increased contractility
increased afterload
Septic shock results in an acute vasodilation which causes a decrease in SVR.
Treatment should be aimed at increasing SVR which would decrease the need for a
continual need to increase C.O. Vasopressors will result in systemic vasoconstriction
and increase SVR therefore increasing afterload of Left Ventricle
A patient admitted to the MICU with a diagnosis of exacerbation of her COPD. Her PAP and POWP values are: PAP = 50/30, mPAP = 37 mmHg and POWP = 10 mmHg. These
values are indicative of: (EXPLAIN):
a. Hypervolemia
b. Hypovolemia
c. LV failure
d. Increased pulmonary vascular resistance
increased pulmonary vascular resistance
In this patient, the PAP is increased but PWP is normal. The PAP reflects the
resistance the right heart has to pump against. Since this is elevated, we know
pulmonary vascular disease is present. The normal wedge pressure shows there is
normal cardiac function. Since we do not know what C.O. is, we can assume the
increased PAP is due to increased PVR
A patient admitted to the MICU with a diagnosis of exacerbation of her COPD. Her PAP and POWP values are: PAP = 50/30, mPAP = 37 mmHg and POWP = 10 mmHg. These
values are indicative of: (EXPLAIN):
What is the major factor contributing to this patient’s hemodynamic problem?
(EXPLAIN)
Since this is a COPD patient, we can expect these pressures, as long as the heart is
functioning normally. COPD patients are in a constant state of hypoxemia which
causes/results in pulmonary vasoconstriction. This causes a chronically elevated PVR.
An 8 year old female is admitted to the hospital due to exacerbation of CHF due to
congenital mitral stenosis. The patient is placed on fluid restriction, dobutamine, a low
sodium diet and diuretics. One day later, the patient’s condition deteriorates and she
becomes progressively hypoxic. She is transferred to the PICU and a BTFDC is inserted.
The values obtained are:
PAP = 48/30
PCWP = 16 mmHg
C.O. = 2.8 L/min
CVP = 14 mmHg
What evidence is currently present that indicates the patient has increased PVR?
the pulmonary artery pressure is > 30/20 which indicates increased PVR and pulmonary hypertension
An 8 year old female is admitted to the hospital due to exacerbation of CHF due to
congenital mitral stenosis. The patient is placed on fluid restriction, dobutamine, a low
sodium diet and diuretics. One day later, the patient’s condition deteriorates and she
becomes progressively hypoxic. She is transferred to the PICU and a BTFDC is inserted.
The values obtained are:
PAP = 48/30
PCWP = 16 mmHg
C.O. = 2.8 L/min
CVP = 14 mmHg
Calculate this patient’s PVR
(mPAP - PCWP) / CO x 80
mPAP = 2(diastolic) + systolic /3
2(30) + 48 /3 = 36 mmHg
(36-16) / 2.8 x 80 = 571 dynes.sec.cm-5
An 8 year old female is admitted to the hospital due to exacerbation of CHF due to
congenital mitral stenosis. The patient is placed on fluid restriction, dobutamine, a low
sodium diet and diuretics. One day later, the patient’s condition deteriorates and she
becomes progressively hypoxic. She is transferred to the PICU and a BTFDC is inserted.
The values obtained are:
PAP = 48/30
PCWP = 16 mmHg
C.O. = 2.8 L/min
CVP = 14 mmHg
What factor(s) are contributing to this problem?
The main problem is the congenital mitral stenosis. The mitral valve is not allowing all the blood that is returning back to the heart and PV system to be ejected from LV which contributes to the decreased C.O., potentially increasing SVR. Also causing increased pressure build up in LA backing up into the pulmonary circulation
increasing pulmonary system pressure creating and increased PVR and increased resistance to RV which can lead to pulmonary edema.
An 8 year old female is admitted to the hospital due to exacerbation of CHF due to
congenital mitral stenosis. The patient is placed on fluid restriction, dobutamine, a low
sodium diet and diuretics. One day later, the patient’s condition deteriorates and she
becomes progressively hypoxic. She is transferred to the PICU and a BTFDC is inserted.
The values obtained are:
PAP = 48/30
PCWP = 16 mmHg
C.O. = 2.8 L/min
CVP = 14 mmHg
Is it possible that this patient has right ventricular failure?
Yes, as stated, the backing up of blood into the pulmonary vasculature due to the
stenotic mitral valve will cause PAP and PVR to increase. This increases the resistance (afterload) the RV has to pump against. The RV will eventually
hypertrophy and will ultimately lead to RV failure.
An 8 year old female is admitted to the hospital due to exacerbation of CHF due to
congenital mitral stenosis. The patient is placed on fluid restriction, dobutamine, a low
sodium diet and diuretics. One day later, the patient’s condition deteriorates and she
becomes progressively hypoxic. She is transferred to the PICU and a BTFDC is inserted.
The values obtained are:
PAP = 48/30
PCWP = 16 mmHg
C.O. = 2.8 L/min
CVP = 14 mmHg
What can you say about the efficacy of diuresis and inotropic drugs?
Both would be efficacious; diuretics would reduce fluid accumulation in the lungs
and peripheral edema if C.O. and vascular volume can be increased. Positive inotropic agents, such as digoxin, would prevent arrhythmias and contractility of the LV. The biggest benefit would be increasing RV function. Negative inotropic agents,
such as Beta Blocker and Calcium Channel Blocker should be given to decrease the HR thereby allowing better filling of the Left ventricle to increase C.O.
An 8 year old female is admitted to the hospital due to exacerbation of CHF due to
congenital mitral stenosis. The patient is placed on fluid restriction, dobutamine, a low
sodium diet and diuretics. One day later, the patient’s condition deteriorates and she
becomes progressively hypoxic. She is transferred to the PICU and a BTFDC is inserted.
The values obtained are:
PAP = 48/30
PCWP = 16 mmHg
C.O. = 2.8 L/min
CVP = 14 mmHg
State what the most likely diagnosis is for this patient and EXPLAIN.
The problem stems from the stenotic mitral valve and not actually the left ventricle
but this patient is likely suffering from acute LVHF with pulmonary vascular disease
and possible cardiogenic pulmonary edema superimposed on a chronic LV failure. The patient’s history indicates she suffers from chronic LV failure but with the exacerbation; pressures are building up from the left atrium which is causing pressures to rise in the pulmonary system as well. Since the patient was placed on fluid restriction and given diuretics, the acute failure is likely causing cardiogenic pulmonary edema.
A 17 year old female is brought to the emergency room complaining of severe
abdominal pain. Before laboratory tests can be obtained, the patient becomes
unconscious and blood pressure falls to 80/50. Stat X-ray reveals free blood in the
abdominal cavity. The patient is rushed to surgery for an exploratory laparotomy, where
it is discovered that she has had a ruptured appendix. The patient is taken to SICU
following surgery and a BTFDC is inserted to evaluate her hemodynamic status. The
values obtained are:
PAP = 25/5
PCWP = 2 mmHg
PvO2 = 50 mmHg
SvO2 = 75%
B/P = 80/50
What do the PvO2 and SvO2 reveal about this patient’s cardiovascular status?
both values are normal indicating good tissue perfusion
A 17 year old female is brought to the emergency room complaining of severe
abdominal pain. Before laboratory tests can be obtained, the patient becomes
unconscious and blood pressure falls to 80/50. Stat X-ray reveals free blood in the
abdominal cavity. The patient is rushed to surgery for an exploratory laparotomy, where
it is discovered that she has had a ruptured appendix. The patient is taken to SICU
following surgery and a BTFDC is inserted to evaluate her hemodynamic status. The
values obtained are:
PAP = 25/5
PCWP = 2 mmHg
PvO2 = 50 mmHg
SvO2 = 75%
B/P = 80/50
The low PCWP is indicative of what two problems?
hypovolemia and sepsis
A 17 year old female is brought to the emergency room complaining of severe
abdominal pain. Before laboratory tests can be obtained, the patient becomes
unconscious and blood pressure falls to 80/50. Stat X-ray reveals free blood in the
abdominal cavity. The patient is rushed to surgery for an exploratory laparotomy, where
it is discovered that she has had a ruptured appendix. The patient is taken to SICU
following surgery and a BTFDC is inserted to evaluate her hemodynamic status. The
values obtained are:
PAP = 25/5
PCWP = 2 mmHg
PvO2 = 50 mmHg
SvO2 = 75%
B/P = 80/50
What does the PAP value reveal?
The PAP reveals there is no presence of pulmonary vascular disease which is further confirmed with the small difference between the PAP diastolic pressure and PCWP.
A 17 year old female is brought to the emergency room complaining of severe
abdominal pain. Before laboratory tests can be obtained, the patient becomes
unconscious and blood pressure falls to 80/50. Stat X-ray reveals free blood in the
abdominal cavity. The patient is rushed to surgery for an exploratory laparotomy, where
it is discovered that she has had a ruptured appendix. The patient is taken to SICU
following surgery and a BTFDC is inserted to evaluate her hemodynamic status. The
values obtained are:
PAP = 25/5
PCWP = 2 mmHg
PvO2 = 50 mmHg
SvO2 = 75%
B/P = 80/50
What is the MOST likely diagnosis for this patient?
Sepsis. Even though cardiac output is not known, blood pressure shows hypotension
but the patient still shows tissue perfusion is adequate, low wedge pressure and
normal pulmonary pressures; along with patient history all point to septic shock.
what is the flow of circulation
- superior vena cava
- RA
- tricuspid valve
- RV
- pulmonic valve
- PA
- pulmonary capillaries
- pulmonary vein
- LA
- mitral (bicuspid) valve
- LV
- aortic valve
- systemic capillaries
- inferior vena cava
calculation for CaO2 (mL/100 mL of blood)
(SaO2 x Hb x 1.34) + (PaO2 x 0.003)
calculation for DO2 (mL O2 / min)
CO x CaO2 x 10
calculation for VO2 (mL/min)
CO x [C(a-v)O2] x 10
calculation for O2 ER (percentage)
VO2 / 1000
calculation for PAO2 (mmHg)
[(PB - PH20) x FiO2] - (PaCO2 x 1.25)
calculation for CvO2 (mL/100 mL of blood)
(SvO2 x Hb x 1.34) + (PvO2 x 0.003)
calculation for shunt (percentage)
(CcO2 - CaO2) / (CcO2 - CvO2)
calculation for CcO2 (mL/ 100 mL of blood)
(Hb x 1.34) + (PAO2 x 0.003)
calculation for O2ER (percentage)
[C(a-v)O2] / CaO2 x 100
normal C(a-v)O2
5 vol%
normal PaO2
95-97 mmHg
normal PvO2
40 mmHg
normal CaO2
20 vol%
normal DO2
1000 mL/min
normal SaO2
95-100%
97%
normal VO2
250 mL/min
25% of DO2
normal O2ER
25%
normal PvCO2
46 mmHg
normal CvO2
15 vol%
normal SvO2
75%
750 mL/min
factors increasing preload
- overstretch ventricle
- cardiac tamponade
- MI
- increase intrathoracic pressures
- hypervolemia
- LVHF
- high ventilating pressures
factors decreasing preload
- hypovolemia
- decreased CO
- decreased SV
what increases contractility
- inotropic agents
- increased CO
- sympathetic stimulation
what decreases contractility
- decreased CO
- hypoxia
- acidosis
- electrolyte abnormalities
- myocardial ischemia
- negative inotropic agents
- physiologic depressants
CO is determined by
- hearts ability to pump the blood it receives
2. peripheral circulatory factors
vascular factors affecting CO
- vascular resistance affects venous return
- blood volume affects venous return
- RAP - force hinders venous return
- mean filling pressure of systemic circulation - force pushes blood back to heart
- vascular resistance
what is Frank-Starling mechanism
defines a characteristic relationship between
- volume filling ventricle
- volume ejected per contraction with muscle stretch
If the ventricle becomes too large, overdistention:
what happens to SV
decreases
increase venous return does what to preload and end-diastolic volume
increases
the greater the stretch of ventricular muscle fiber does what
- increase force of contraction = increase SV
2. increase SA node firing = increase SV
indication for art-line
- presence of severe hypotension (shock)
- presence of severe hypertension
- unstable respiratory failure
- need for frequent ABG assessment
- need for administration of blood pressure meds (vasodilator, inotropic)
where is placement of art-lines
- radial artery (most common)
2. femoral artery
complications of art-line
- ischemia
- hemorrhage
- infection
indication for CVP
- to assess RV function
- patient who benefit (major surgery or blood loss, cardiogenic or non-cardiogenic pulmonary edema, monitor fluid therapy, suspect damage to RV, can be used for blood samples)
where is placement of CVP
- internal jugular (most popular)
- subclavian vein
- femoral artery
complications of CVP
- during placement (bleeding, pneumothorax)
2. over time (infection, embolus, air embolus)
indication of PAC
- evaluation of LV function
- allow assessment of (LV fill pressure, PVR, arteriovenous oxygen difference, mixed venous oxygen levels)
- severe cardiogenic pulmonary edema
- patients with ARDS who are hemodynamically unstable
- patient who have had major thoracic surgery
- patient with septic or severe cardiogenic shock
where is placement of PAC
- subclavian vein
2. internal jugular vein
complications of PAC
- during placement (hemothorax, pneumothorax, blood vessel damage)
- as passing (dysrhythmias)
- after placement (infection, thrombus, embolism, pulmonary infarction, bleeding, hematoma)