Fiser.16.CCM Flashcards
1
Q
What is a normal cardiac output in L/min?
A
4-8 LPM
2
Q
What is a normal cardiac index in L/min?
A
2.5-4 L/min
3
Q
What is a normal systemic vascular resistance (SVR)?
A
800-1400
4
Q
What is a normal PCWP?
A
11 +/- 4
5
Q
What is a normal CVP?
A
7 +/- 2
6
Q
What is a normal pulmonary artery pressure (PAP)?
A
25/10 +/- 5
7
Q
What is a normal mixed venous O2 sat (SvO2)?
A
75 +/- 5
8
Q
What is the equation for MAP?
A
MAP = CO x SVR
9
Q
What is the equation for CI?
A
CI = CO / BSA
10
Q
What percent of cardiac output goes to the kidney?
A
25%
11
Q
What percent of cardiac output goes to the brain?
A
15%
12
Q
What percent of cardiac output goes to the heart?
A
5%
13
Q
How do you define preload according to the left ventricle?
A
Preload = left ventricular end-diastolic length
14
Q
What two variables is preload linearly related to?
A
Left ventricular end-diastolic volume and filling pressure
15
Q
How does preload relate to recruitable stroke volume?
A
preload relates to changes in stroke volume according to recruitable muscles
16
Q
how does preload relate to the shape of the starling curve?
A
Increased preload at the steep part of the starling curve means you have lots of recruitable muscles and will have large increase in SV versus negligible increase in SV when increased
17
Q
How do you define afterload according to the ventricle?
A
Resistance against the ventricle contracting (like SVR: systemic vascular resistance)
18
Q
What are three determinants of stroke volume?
A
LV EDV, contractility, and afterload
19
Q
What is the equation for stroke volume?
A
LVEDV - LVESV
20
Q
What is the equation for ejection fraction?
A
Stroke volume / LVEDV
21
Q
What are two determinants of end-diastolic volume? (EDV)
A
Preload and distensibility of ventricle
22
Q
What are the two determinants of end-systolic volume? (ESV)
A
Determined by contractility and afterload
23
Q
What is the heart rate up to which cardiac output increases and then decreases?
A
CO increases with HR up to 120-150 bpm, then starts to go down
24
Q
Why does this phenomenon between HR and CO occur?
A
Because as HR increases, you get decreased diastolic filling time
25
What percent of LVEDV is accounted for by atrial kick?
20%
26
Describe the Anrep effect
Automatic increase in contractility 2/2 increased afterload
27
Describe the Bowditch effect
Automatic increase in contractility 2/2 increased heart rate
28
What is the equation for arterial O2 content (CaO2)?
CaO2 = Hb x 1.34 x O2sat + (PO2 x 0.003)
29
What is the equation for O2 delivery?
CO x arterial O2 content (CaO2) x 10
30
What is the equation for O2 consumption? (VO2)
VO2 = CO X (CaO2 - CvO2) CvO2 = venous O2 content
31
What is the normal O2 delivery to consumption ratio?
5:1
32
What measure of cardiac activity increases to keep the O2 delivery:consumption ratio constant?
Cardiac output increases to keep this ratio constant
33
Why is O2 consumption usually supply-independent?
O2 consumption does not change until low levels of delivery are reached
34
What causes right shift of the O2-Hb dissociation curve? (5)
Increased O2 unloading via increased CO2; increased temperature; increased ATP; increased 2,3-DPG; decreased pH (increased acidity)
35
What occurs with a left shift of the O2-Hb dissociation curve?
Increased O2 binding
36
What is a normal venous O2 saturation (SvO2)?
75 +/- 5%
37
What is the pathophys behind increased SvO2? (2)
Increased shunting or decreased O2 extraction
38
Name eight causes of increased SvO2?
Sepsis, cirrhosis, cynaide toxicity, hyperbaric oxygen, hypoterhmia, paralysis, coma, sedation
39
What is the pathophys behind decreased SvO2? (5 possible MOA)
Increased O2 extraction; Decreased O2 delivery Decreased O2 saturation Decreased bicarb Malignant hyperthermia
40
Name six conditions that can alter wedge pressure
Pulmonary HTN; high PEEP Aortic regurgitation; poor LV compliance Mitral stenosis; mitral regurgitation
41
In which zone of the lung should a Swan Ganz catheter be placed?
Zone III
42
How should you treat hemoptysis after flushing the Swan Ganz catheter? (4)
Increase PEEP to tamponade the pulmonary artery bleed Mainstem intubate the unaffected side Can attempt to place Fogarty balloon down affected side May need thoracotomy with lobectomy if these interventions do not work
43
Name two relative contraindications to a Swan-Ganz catheter
Previous pneumonectomy, left BBB
44
What is the distance of the right SCV to the Swan-Ganz catheter wedge?
45cm
45
What is the distance of the right IJ to the Swan-Ganz catheter wedge?
50cm
46
What is the distance of the left SCV to the Swan-Ganz catheter wedge?
55cm
47
What is the distance of the left IJ to the Swan-Ganz catheter wedge?
60cm
48
Does an echo measure pulmonary vascular resistance?
nope
49
What is the only way to measure pulmonary vascular resistance?
Swan-Ganz catheter
50
When in the respiratory cycle should you measure wedge pressure for ventilated patients?
End-expiration
51
When in the respiratory cycle shoul you measure wedge pressure for nonventilated patients?
end expiration
52
What are the two primary determinants (in order) of myocardial O2 consumption?
Increased ventricular wall tension (#1) and heart rate
53
Where do bronchial veins empty?
empty into pulmonary veins
54
How does this anatomy affect O2 saturations in the left ventricle versus pulmonary capillaries?
LV PO2 is ~5mmHg lower than pulmonary capillaries
55
What is a normal alveolar-arterial gradient?
10-15mmHg in a normal nonventilated patient
56
What location has blood with the lowest venous O2 saturation in the body?
coronary sinus blood
57
What is the venous O2 sat in coronary sinus blood?
30%
58
What is the most basic definition of shock?
Inadequate tissue oxygenation
59
Name two S/Sx that occur with progressive shock
Tachypnea and altered mental status with progressive shock
60
What is the MCC of adrenal insufficiency?
Withdrawal from exogenous steroids
61
What are six S/Sx of acute adrenal insufficiency?
Cardiovascular collapse unresponsive to fluids and pressors; N/V; abdominal pain; fever; lethargy
62
Name two lab findings a/w adrenal insufficiency
Hypoglycemia, hyperkalemia
63
How do you treat acute adrenal insufficiency?
dexamethasone
64
How strong is hydrocortisone compared to cortisone?
They are equal in strength
65
Name three steroids that are five times stronger than hydrocortisone or cortisone
Prednisone; prednisolone; methylprednisolone
66
Name one steroid that is thirty times stronger than hydrocortisone or cortisone
dexamethasone
67
What is the underlying cause of neurogenic shock (MOA)?
Loss of sympathetic tone 2/2 head or spine injury
68
What are the three S/Sx a/w neurogenic shock?
Low HR, low BP, warm skin
69
How do you treat neurogenic shock? (2 steps)
IVF first, then phenylephrine after resuscitation
70
What is the first alteration in vital signs a/w hemorrhagic shock?
Narrowed pulse pressure 2/2 increased diastolic pressure
71
What type of shock is caused by cardiac tamponade?
Cardiogenic shock
72
What is the mechanism of hypotension 2/2 cardiac tamponade?
Decreased ventricular filling 2/2 fluid accumulation in pericardial sac
73
What is Beck’s triad?
Hypotension, JVD, muffled heart sounds
74
What is the first sign of cardiac tamponade seen on echo?
Impaired diastolic filling of the right atrium is the first sign of cardiac tamponade on echo
75
What is a unique characteristic of pericardial blood?
It does not clot
76
What is the treatment of cardiac tamponade?
Fluid resuscitation to temporize situation, then pericardial window or pericardiocentesis
77
What is the pattern of CVP/PCWP, CO, and SVR seen with hemorrhagic shock?
Low CVP/PCWP; low CO; elevated SVR
78
What is the pattern of CVP/PCWP, CO, and SVR seen with septic/hyperdynamic shock?
low CVP/PCWP; elevated CO; low SVR
79
What is the pattern of CVP/PCWP, CO, and SVR seen with cardiogenic shock?
elevated CVP/PCWP; low CO; elevated SVR
80
What is the pattern of CVP/PCWP, CO, and SVR seen with neurogenic shock?
low CVP/PCWP; low CO; low SVR
81
What is the pattern of CVP/PCWP, CO, and SVR seen with adrenal insufficiency?
low CVP/PCWP; low CO; low SVR
82
What is the early sepsis triad?
Hyperventilation, confusion, hypotension
83
What are the insulin and glucose findings with early gram negative sepsis and why?
Low insulin, hyperglycemia 2/2 impaired glucose utilization
84
What are the insulin and glucose findings in late gram-negative sepsis and why?
Elevated insulin and hyperglycemia 2/2 insulin resistance
85
When does hyperglycemia present in the septic patient?
Usually presents just before the patient becomes clinically septic
86
What is the rapid neurohormonal response to hypovolemia? (2)
Release of epinephrine and norepinephrine
87
Where are epinephrine and norepinephrine released from?
Adrenals (adrenergic release)
88
What are the effects of the release of epinephrine and norepinephrine in response to hypovolemia?
Results in vasoconstriction and increased cardiac activity
89
What is the sustained neurohormonal response to hypovolemia? (3)
Renin, ADH, ACTH
90
Where is renin released from and what is its effect?
Released from kidney, activated renin-angiotensin-aldosterone system for vasoconstriction and H2O reabsorption
91
Where is ADH released from and what does it do?
Released from pituitary and causes reabsorption of water
92
Where is ACTH released from and what is its effect?
reabsorption of water Released from pituitary and increases cortisol
93
What are the three S/Sx a/w fat emboli?
Petichiae, hypoxia, and confusion (similar to presentation of PE)
94
What pathology test can be used to confirm presence of fat emboli?
Sudan red stain may show fat in sputum and urine
95
What is the MCC of fat emboli?
Lower extremity fractures or orthopedic procedures (hip / femur)
96
What are the 6 S/Sx a/w PE?
CP; SOB; tachycardia; tachypnea; hypotension/shock if massive PE
97
What are three ABG findings a/w PE?
Respiratory alkalosis, low PO2, low PCO2
98
What is the MC source of PE?
Iliofemoral region
99
What are the two medical treatments for PE?
Heparin to coumadin
100
When is surgery indicated for PE?
Patient in shock despite massive pressors and inotropes
101
What approach should you use when operating for PE?
Open or percutaneous (suction catheter) embolectomy
102
What are the steps to manage an air embolism?
Patient head down and LLD to keep air in the RV and RA; aspirate air out with central line or PA catheter to RA/RV
103
When in the cardiac cycle does the intra-aortic balloon pump inflate and deflate?
Inflates on diastole and deflates on systole
104
When on the EKG cycle does the intra-aortic balloon pump inflate and deflate?
Inflates on T-wave and deflates on P-wave
105
What cardiac condition is a contraindication to intra-aortic balloon pump use?
Aortic regurgitation
106
Where should the tip of the intra-aortic balloon pump catheter be placed?
Just distal to the left subclavian (1-2cm below the top of the arch)
107
Name two indications for intra-aortic balloon pump use
Cardiogenic shock s/p CABG or MI Patients with refractory angina awaiting revascularization
108
How does the intra-aortic balloon pump affect afterload?
Decreases afterload by deflation during systole (negative pressure down the aorta)
109
How does the intra-aortic balloon pump affect diastolic BP and what effect does this have on coronary perfusion?
Increases diastolic BP by inflating during diastole leads to improved diastolic coronary perfusion
110
What do alpha-1 receptors do? (3)
Vascular smooth muscle constriction; gluconeogenesis; glycogenolysis
111
What do alpha-2 receptors do? (1)
Venous smooth muscle constriction
112
What do beta-1 receptors do?
Affect myocardial contraction and rate
113
What do beta-2 receptors do? (5)
Relaxes bronchial smooth muscle Relaxes vascular smooth muscle Increases insulin, glucagon, and renin
114
What do dopamine receptors do?
Relax renal and splanchnic smooth muscle
115
what is the initial dose of dopamine in kg/min?
2-5ug/kg/min initially
116
which receptors and where are activated when dopamine is administered at 2-5ug/kg/min?
dopamine receptors (renal)
117
which receptors and what effects are activated when dopamine is administered at 6-10 ug/kg/min?
beta adrenergic receptors (heart contractility)
118
which receptors and what effects are activated when dopamine is administered at \>10 ug/kg/min?
alpha adrenergic receptors causing vasoconstriction and increased bp
119
what is the initial starting rate of the dobutamine in kg/min?
3ug/kg/min initially
120
which receptors and what effects are activated with dobutamine? How do these effects differ by dose of dobutamine administered
beta-1 receptors, causing increased contractility initially and tachycardia at higher doses
121
what is the MOA of milrinone?
phosphodiesterase inhibitor causing increased cAMP and then increased calcium flux
122
what is the clinical effect of milrinone? (3)
incresaed myocardial contractility, vascular SM relaxation, and pulmonary vasodilation
123
what is the initial rate of phenylephrine in ug/min?
10ug/min initially
124
what is the receptor activated and effect of phenylephrine?
alpha-1 receptor causing vasoconstriction
125
what is the initial dose of norepinephrein in ug/min?
5ug/min
126
what is the effect of norepinephrine at low doses and high doses and its associated effects
low dose: causes beta 1 activation = increased contractility high dose: alpha 1 and alpha 2 activation
127
what is the relevance of norepinephrine in terms of GI/abdominal surgery?
norepinephrine is a potent splanchnic vasoconstrictor
128
what is the initial dose of epinephrine in ug/min?
1-2ug/min initially
129
what is the effect of epinephrine at low doses (and which receptors are activated)?
beta 1 and beta 2 activation, causing increased contractility and vasodilation. Can therefore cause reduced BP at low doses
130
what is the effect of epinephrine at high doses and which receptors are activated?
alpha 1 and alpha 2 activation leading to vasoconstriction
131
what are the 2 possible cardiac complications a/w high doses of epinephrine?
increased cardiac ectopic pacemaker activity and increased myocardial O2 demand
132
what is the initial dose of isoproterenol in ug/min?
1-2ug/min initially
133
with isoproterenol, which receptors are activated and what are their effects?
beta 1 and beta 2 are activated, causing increased heart rate and contractility + vasodilation
134
what are 3 adverse cardiovascular side effects a/w isoproterenol?
extremely arrhytmogenic, increased heart metabolic demand, rarely actually reduces BP
135
what is the action of V1 (vasopressin) receptors?
vasoconstriction of vascular smooth muscle
136
what is the action of intrarenal V2 (vasopressin) receptors?
water reabsorption at collecting ducts
137
what is the action of extrarenal V2 (vasopressin) receptors?
mediates release of factor VIII and von willebrand factor
138
what is the cardiovascular effect of nipride?
arterial vasodilator
139
what is an adverse effect of nipride?
cyanide toxicity at high doses
140
at what doses/ duration of nipride should you worry about cyanide toxicity?
at doses \> 3ug/kg/min x 72 hours
141
what labs should you check to monitor for CN toxicity in patients on nipride gtts?
check thiocyanate levels and for signs of metabolic acidosis
142
what are the two treatments for cyanide toxicity and in what order are they administered?
amyl nitrite and then sodium nitrite
143
what are the three cardiovascular effects of nitroglycerin?
predominantly a venodilator leading to decreased myocardial wall tension 2/2 reduced preload; moderate coronary vasodilator
144
what receptor does hydralazine act on and what is its effect?
alpha-blocker causing reduced BP
145
what is the formula for compliance in the lungs?
change in volume / change in pressure
146
how easy is it to ventilate a patient with high compliance of the lungs?
it is easy to ventilate
147
name 5 comorbidities a/w decreased pulmonary compliance
ARDS, fibrotic lung diseases, reperfusion injury, pulmonary edema, atelectasis
148
define inspiratory reserve volume, expiratory reserve volume, tidal volume, residual volume, total lung capacity, vital capacity, inspiratory capacity, and functional residual capacity
see photo
149
what is the effect of aging on FEV1
reduces FEV1
150
what is the effect of aging on vital capacity?
reduced vital capacity
151
what is the effect of aging on the functional residual capacity?
increased functional residual capacity
152
what is the V/Q ratio in the lungs?
ventilation to perfusion ratio
153
what is the V/Q ratio in the upper lobes versus lower lobes
V/Q ratio highest in upper lobes and lowest in lower lobes
154
what are the two effects of increased PEEP on the vent that causes improved oxygenation?
alveoli recruitment that improves functional residual capacity
155
what are two alterations to the vent settings you can do to decrease CO2? (to treat hypercarbia)
increase RR or increase volume
156
What is a normal negative inspiratory force (NIF) for vent weaning?
\> 20
157
what is a normal FiO2 for vent weaning?
\< or = 40%
158
what is a normal PEEP for vent weaning?
5 (physiologic)
159
what is a normal pressure support (PS) for vent weaning?
5
160
what is a normal RR for vent weaning
24 breaths per minute
161
what is a normal heart rate for vent weaning?
\< 120 beats per minute
162
what is a normal PO2 on ABG for vent weaning?
\> 60mmHg
163
what is a normal PCO2 on ABG for vent weaning?
\<50mmHg
164
what is a normal pH on ABG for vent weaning?
pH 7.35-7.45
165
what is a normal O2 saturation for vent weaning?
\>93% O2 sat
166
what are three clinical (bedside) indicators that a patient is ready to be weaned off the vent?
off pressors, follows commands, can protect airway
167
how does increased pressure support make breathing on the vent easier?
decreases the work of breathing with inspiratory pressure held constant until minimum volume is achieved
168
at what level should try to keep FiO2 at or below and why?
keep FiO2 at or below 60% to prevent O2 radical toxicity
169
At what plateaus and peaks are you at risk for barotrauma?
plateaus \> 30 and peaks \> 50
170
what two changes to the ventilator can you make to reduce the risk of barotrauma?
reduce tidal volumes and consider pressure control ventilation
171
What is the best vent setting to alter to improve oxygenation and why?
increase PEEP because it increases functional residual capacity and compliance by keeping alveoli open = improved oxygenation
172
define total lung capacity
lung volume after maximal inspiration
173
what is the equation for total lung capacity?
TLC = FVC + RV = forced vital capacity + residual volume
174
what is the definition of forced vital capacity?
FVC is maximal exhalation after maximal inhalation
175
what is the definition of residual volume?
lung volume after maximal expiration
176
what percent of total lung capacity is residual volume?
20% TLC = RV
177
define tidal volume
the volume of air with normal inspiration and expiration
178
define functional residual capacity
lung volume after normal exhalation
179
\*\*PHOTO\*\* what is the equation for functional residual capacity
FRC = expiratory reserve volume + residual volume
180
define expiratory reserve volume
voluem of air that can be forcefully expired after normal expiration
181
what lung pathology can be caused by surgery and how does it affect functional residual capacity?
surgery can cause atelectasis, leading to reduced FRC
182
what lung pathology can be caused by sepsis and how does this affect functional residual capacity?
sepsis can cause ARDS leading to reduced functional residual capacity
183
what lung pathologies (3) can be caused by trauma and how does this affect functional residual capacity?
trauma can cause lung contusion, atelectasis, and ARDS that all reduce FRC
184
define inspiratory capacity
maximum air breathed in from FRC
185
what is FEV1
forced expiratory volume in 1 second after maximal inhalation
186
what is the equation for minute ventilation?
MV = RR x TV = respiratory rate x tidal volume
187
how does restrictive lung disease affect total lung capacity, residual volume, and forced vital capacity?
reduces TLC, RV, and FVC
188
how does restrictive lung disease affect FEV1?
can be normal or increased
189
how does obstructive lung disease affect total lung capacity, residual volume, and FEV1?
increased TLC and RV, decreased FEV1
190
how does obstructive lung disease affect forced vital capacity?
FVC can be normal or decreased
191
to what level of the lung is considered "dead space"
to the level of the bronchiole
192
what is a normal volume of lung dead space?
150 mL
193
what is the definition of lung dead space in terms of ventilation and perfusioN?
it is the region of the lung that is ventilated but not perfused
194
name 5 comorbidities that can cause increase in lung dead space
reduced cardiac output, PE, pulmonary hypertension, ARDS, and excessive PEEP
195
what alteration in ABG occurs with increased dead space?
elevated CO2 (hypercarbia)
196
what is the underlying abnormality in the breathing cycle that causes increased WOB in COPD?
prolonged expiratory phase in COPD causes increased WOB
197
what is the underlying pathophysiology of ARDS
mediated primarily by PMNs, get increased proteinaceous material, increased A-a gradient, increased pulmonary shunting
198
what is the MCC of ARDS?
pneumonia
199
name six other cuases of ARDS
sepsis; multitrauma; severe burns; pancreatitis; aspiration; DIC
200
name the four criteria for diagnosis of ARDS
acute onset; bilateral pulmonary infiltarations; PaO2/FiO2 \< or = 300; absence of heart failure with wedge pressure \< 18mmHg
201
what pH and volume of aspiration are associated with increased lung damage?
pH \< 2.5 and volume \> 0.4cc/kg
202
Define Mendelson's syndrome
chemical pneumonitis from aspiration of gastric secretions
203
What is the most frequent site of aspiration?
superior segment of RLL
204
define atelectasis
collapse of alveoli resulting in reduced oxygenation, usually caused by poor inspiration postop
205
what are the S/Sx of atelectasis (3)
fever, tachycardia, hypoxia
206
what is the MCC of fever 48 hours postop?
atelectasis
207
name three risk factors for postop atelectasis
COPD, upper abdominal surgery, obesity
208
name three treatments for atelectasis
incentive spirometer; pain control; ambulation
209
name 6 underlying causes of inaccurate transcutaneous pulse ox reading
nail polish; dark skin; low=flow states; ambient light; anemia; vital dyes
210
what is the effect of hypoxia on pulmonary vasculature?
pulmonary vasoconstriction
211
what is the effect of alkalosis on pulmonary vasculature?
pulmonary vasodilation
212
what is the effect of acidosis on pulmonary vasculature?
pulmonary vasoconstriction
213
what is the effect of prostacyclin (PGI2) on pulmonary vasculature?
pulmonary vasodilation
214
what is the effect of nitric oxide on pulmonary vasculature?
pulmonary vasodilation
215
what is the effect of histamine on pulmonary vasculature
pulmonary pulmonary vasoconstriction
216
what is the effect of serotonin on pulmonary vasculature?
pulmonary vasoconstriction
217
what is the effect of nipride/nitroprusside on oxygenation?
causes pulmonary shunting
218
what is the effect of bradykinin on pulmonary vasculature?
pulmonary vasodilation
219
what is the effect of nitroglycerin on pulmonary oxygenation?
causes pulmonary shunting
220
what is the effect of TXA2 on pulmonary vasculature?
causes pulmonary vasoconstriction
221
what is the effect of nifedipine on pulmonary oxygenation?
causes pulmonary shunting
222
what is the MCC of postop renal failure?
intraop hypotension
223
what percentage of nephrons need to be damaged before renal dysfunction occurs?
70%
224
what is the best lab test for azotemia?
FeNa
225
what is azotemia?
elevated BUN
226
what is the formula for FeNa?
U need to pee [(urine Na\*plasma Cr)/(urine Cr \* plasma Na)]
227
What are the labs / maneuvers you should initially do when you suspect renal failure?
check Foley for kinks / blockage; flush Foley; get serum and urine lytes; check FeNa
228
What is the urine osmolarity in prerenal renal failure?
\>500
229
what is the urine osmolarity in parenchymal renal failure?
250-350
230
what is the Urine:Plasma osmolarity ratio in prerenal failure?
\>1.5
231
what is the Urine:Plasma osmolarity ratio in parenchymal renal failure?
\<1.1
232
what is the Urine:Plasma creatinine ration in prerenal failure?
\>20
233
what is the Urine:Plasma creatinine ration in parenchymal renal failure?
\<10
234
what is the Urine sodium in prerenal failure?
\<20
235
what is the Urine sodium in parenchymal renal failure?
\>40
236
what is the FeNa in prerenal failure?
\<1%
237
what is the FeNa in parenchymal renal failure?
\>3%
238
What is your first intervention for oliguria and goal CVP?
make sure patient is volume loaded with CVP 11-15mmHg
239
What is your second intervention for oliguria?
try diuretic trial, usually Lasix/furosemide
240
what is the third intervention for oliguria
HD if needed
241
name six indications for dialysis
fluid overload, hyperkalemia, metabolic acidosis, uremic encephalopathy, uremic coagulopathy, poisoning
242
what are the major pro and con for HD over CVVH?
pro: rapid / con: causes large volume shifts
243
what are the pros of CVVH over HD
pro: slower, good for ill patients who cannot tolerate large volume shifts (ex: septic shock)
244
What is the expected change in Hct with each liter taken off with HD?
expect Hct to increase by 5-8 with each liter removed
245
what is the MoA of renin release by the juxtoglomerular apparatus?
renin released in response to decreased pressure sensed by the JGA in the kidney
246
what is the MOA of renin release by the macula densa?
renin released in response to increased sodium concentrations sensed by the macula densa in the distal convoluted tubule
247
how does beta adrenergic stimulation affect renin release?
causes renin release
248
how does potassium affect renin release?
hyperkalemia causes renin release
249
where is the angiotensin converting enzyme located?
in the lung
250
what does the angiotensin converting enzyme do?
converts angiotensin I to angiotensin II
251
what is the effect of angiotensin II on the adrenal cortex?
causes adrenal cortex to release aldosterone
252
what is the effect of aldosterone on the kidney? (MOA, pathophysiology)
aldosterone acts on the distal convoluted tubule to reabsorb water by upregulating Na/K ATPase on the membrane, causing Na to be reabsorbed and K to be secreted
253
What is the effect of angiotensin II on the cardiovascular system? (3)
vasoconstriction, increased HR, increased contractility
254
What is the effect of angiotensin II on glucose balance?
causes glycogenolysis and gluconeogenesis
255
what is the effect of angiotensin II on renin?
inhibits renin relase
256
what is the MOA / pathophysiology of atrial natriuretic peptide / atrial natriuretic factor release?
released from the atrial wall with atrial dstension
257
what is the function of atrial natriuretic peptide (AKA atrial natriuretic factor)?
inhibits Na and water resorption in the collecting ducts
258
what is the cardiovascular effect of atrial natriuretic peptide (AKA atrial natriuretic factor)/
vasoconstrictor
259
which limb of the nephron (afferent or efferent) controls GFR?
efferent limb controls GFR
260
how do NSAIDS cause renal injury?
inhibit prostaglandin synthesis, resulting in renal arteriole vasoconstriction
261
how do aminoglycosides cause renal injury?
direct tubular injury
262
how does myoglobin cause renal injury?
direct tubular injury
263
how do you treat/prevent myoglobin-induced renal injury?
alkalinize urine
264
how do contrast dyes cause renal injury?
direct tubular injury
265
how do you treat/prevent contrast-induced renal injury?
prehydration before contrast exposure, bicarb, N-acetylcysteine
266
what does SIRS stand for?
systemic inflammatory response syndrome
267
name 5 causes of SIRS
shock, infection, burns, multitrauma, pancreatitis, severe inflammatory responses
268
what is the most potent stimulus for SIRS
endotoxin with lipopolysaccharide (lipid A) is the most potent stimulus for SIRS
269
what inflammatory factor is stimulated by lipid A
TNF release
270
Name the two molecules that are released in response to inflammation that cause SIRS
systemic inflammation causes TNF-alpha and IL1 release, leading to shock and multiorgan dysfunction
271
name four pathophysiological disturbances that occur with SIRS
capillary leakage; microvascular thrombi; hypotension; end-organ dysfunction
272
Define sepsis according to SIRS
Sepsis = SIRS + infection
273
how many of the SIRS criteria need to be met to diagnose SIRS?
need 2 or more SIRS criteria
274
name the four SIRS criteria
Temperature: \>38C or \<36C; HR: \>90; RR \>20 or PaCO2 \< 32; WBC \> 12 or \<4
275
What is the definition of shock in a patient with sepsis/SIRS?
areterial hypotension despite adequate volume resuscitation (inadequate tissue oxygenation)
276
Define multisystem organ dysfunction
progressive but reversible dysfunction of 2+ organs arising from an acute disruption of normal homeostasis
277
what are the dignostic criteria for significant organ dysfunction of the pulmonary system? (2)
need for mechanical ventilation; PaO2:FiO2 ratio of \<300 x 24 hours
278
what are the dignostic criteria for significant organ dysfunction of the cardiovascular system? (2)
need for inotropic drugs \*OR\* CI \< 2.5L/min/m2
279
what are the dignostic criteria for significant organ dysfunction of the renal system? (2)
creatinine \>2x baseline on 2 consecutive days OR need for dialysis
280
what are the dignostic criteria for significant organ dysfunction of the hepatic system? (2)
bilirubin \>3 mg/dL on two consecutive days OR PT \> 1.5 control
281
what are the dignostic criteria for significant organ dysfunction of the nutrition system? (3)
10% reduction in lean body mass; albumin \< 2.0; total lymphocyte count \<1
282
what are the dignostic criteria for significant organ dysfunction of the CNS? (1)
GCS \< 10 without sedation
283
what are the dignostic criteria for significant organ dysfunction of the coagulation systsem? (3)
platelets \< 50; fibrinogen \< 100; OR need for factor replacement
284
what are the dignostic criteria for significant organ dysfunction of the immunologic/host defenses system (2)
WBC \< 1 or invasive infection including bacteremia
285
desribe the progression from insult to SIRS to sepsis to septic shock to MODS
\*\*FLOWChART\*\*
286
what drugs on board preclude diagnosis of braindeath
any drugs but especially phenobarbital, pentobarbital, or EtOH
287
what metabolic derangements preclude diagnosis of brain death?
hyperglycemia, uremia
288
what vital signs preclude diagnosis of brain death (3)
temperature \< 32C, SBP \<90; desaturation with apnea test
289
how is the apnea test for brain death administered?
patient is preoxygenated with a catheter delivering O2 at 8LPM at the carina via the ETT and PCO2 should be normal before the start of the test. Patient is then disconnected from the ventilator for 10 minutes
290
What are two findings of the apnea test that are positive for braindeath?
CO2 \> 60mmHg or increase in CO2 by 20mmHg by the end of the test meets brain death criteria
291
name 8 findings that must be present for 6-12 hours to allow dx of brain death
unresponsive to pain; absent cold caloric oculovestibular reflexes; absent oculocephalic (dolls eye/tracking) reflex; no spontaneous respirations; no corneal reflex; no gag reflex; fixed and dilated pupils; positive apnea test
292
what are the EEG findings in brain death?
electrical silence
293
what are MRA findings in brain death?
no blood flow to brain
294
what are deep tendon reflexes with brain death?
you can still have DTRs with brain death
295
what are three findings on the apnea test that are NEGATIVE for brain death?
BP drops to \<90mmHg, patient desaturates to \<85% on pulse ox; or spontaneous breathing occurs
296
what do you do when a patient has a negative apnea test when testing for brain death
if negative, terminate the test and put patient back on the ventilator
297
What are the S/Sx of CO poisoning?
HA, nausea, confusion, coma, death
298
what are the pulse ox findings with CO poisoning?
falsely elevated O2 sat on pulse ox
299
what is the MOA of CO poisoning?
CO binds directly to hemoglobin and creates carboxyhemoglobin
300
How do you treat CO poisoning?
100% O2 on the ventilator is usually enough to displace the CO molecules, rarely need hyperbaric O2
301
what is an abnormal carboxyhemoglobin level in a non-smoker?
\>10%
302
what is an abnormal carboxyhemoglobin level in a smoker?
\>20%
303
what is methemoglobin and how does it affect oxygenation?
Hb bound to Fe3+ becomes methemoglobin, which binds more tightly to O2 and has reduced unloading in tissues
304
name two antibiotics associated with methemoglobinemia
Bactrim and dapsone
305
name three anesthetics a/w methemoglobinemia
locals: articaine, benzocaine, and prilocaine
306
name two sources of nitrates that can cause methemoglobinemia
chemicals for patina/leather (bismuth nitrate) and Hurricane spray (topical benzocaine)
307
what are the O2 sats found with methemoglobinemia
reduced, O2 sats will read 85% ish
308
how do you treat methemoglobinemia and what is its MOA?
methylene blue restores iron in hemoglobin to the normal (reduced) state by acting as an electron acceptor
309
what can happen with patients on SSRIs treated with methylene blue?
can cause serotonin toxicity because methylene blue inhibits monoamine oxidase
310
what is critical illness polyneuropathy and how does it affect ventilation?
with prolonged sepsis, you can get motor \> sensory neuropathy, can lead to failure to wean from ventilation
311
where is xanthine oxidase located?
in endothelial cells
312
what does xanthine oxidase do and how is it a/w reperfusion injury?
XO forms toxic oxygen radicals with reperfusion
313
how is xanthine oxidase involved with purine metabolism?
involved with purine metabolism to breakdown to uric acid
314
which cells are the most important mediators of reperfusion injury?
PMNs migrate to reperfused tissue after injury as inflammatory reaction --\> damage
315
how does DKA present? (4 S/Sx)
N/V, thirst, polyuria
316
what are 4 chemistry findings a/w DKA?
elevated glucose, elevated ketones, elevated potassium, low sodium
317
how do you treat DKA initially?
NS and insulin gtt initially
318
what are the 4 S/Sx a/w EtOH withdrawal and when do they occur in a hospitalization
occurring after 48 hours in the hospital: HTN, tachycardia, delirium, seizures
319
how do you treat EtOH withdrawal? (6 meds)
thiamine, folate, B12, Mag, K + PRN Ativan (lorazepam)
320
when does ICU / hospital psychosis occur in a hospitalizaiton / postop?
lucid interval to psychosis at POD3
321
what do you need to rule out before you diagnose ICU/hospital psychosis?
metabolic causes (hypoglycemia, DKA, hypoxia, hypercarbia, electrolyte imbalances) and organic causes (MI, CVA)
