3. Shock Flashcards
4 broad categories of shock
obstructive
hypovolemic
cardiogenic
distributive
Typical first sign of hemorrhagic shock
slight incr dbp and narrowing pulse pressure
What is a base deficit?
amount of strong base that would have to be addedto 1L blood to normalize pH
N base deficit?
-2 max, then +
Five categories of shock according to primary tx: ddx of cause of Primary vol of infusion
Hemorrhagic shock: trauma, GI, body cavity
Hypovolemia: GI loss, dehydration from insensible loss, third spacing
Five categories of shock according to primary tx: ddx of cause of vol infusion and vp support
septic shock
central neurogenic shock
anaphylactic shock
drug OD
Five categories of shock according to primary tx: ddx of cause of improved pump function by infusion of inotropic support or reversal of the cause of pump dysfunction
MI: CA thrombosis, arterial hypot with ischemia
Cardiomyopathy: acute myocarditis, chronic disease of m (db, ischemic, infiltrate, endo, congenital)
Cardiac rhythm: afib with RVR, vfib, svt
Septic shock with myo failure
OD of negative ino drug: beta blocker, CCB
Structural: trauma, ventriculoseptal, papillary m
Five categories of shock according to primary tx: ddx of cause of Immed relief from obstruction from CO
PE
cardiac tamp
tension ptx
valvular dysfunc: ac thrombosis prosth valve or critcal AS
CHD newborn
Critical idiopathic subaortic stenosis
Five categories of shock according to primary tx: ddx of cause of Sp antidote
co
methemoglobinemia
H sulfide
cyanide
First ph of damage in hemorrhagic shock vs secondary
inflamm cascade
reperfusion = release of these inflamm mediators - neutrophils become more aggressive
Spetic shock:causes three primary effects to address in resuscitation:
hypovolemia
cardiovascular depression
induction of systemic inflammation
How does septic shock cause relative and absolute hypovolemia?
abs: GI vol loss, tachycardia, sweat, decr fluid intake
rel: from incr venous capacitance and capillary leak with loss of IV vol by third space
How does septic shock cause myocardial depresssion:
likely secondary circulating inflammatory mediators like TNF alpha, IL beta, overproduction of NO, impaired mitochrondrial oxydative phosphorylation
Cardiogenic shock: ddx (general categories) of cause
ischemia
inflamm
toxins
immune injury
Neurogenic shock - ED presentation as compared to typical defn?
range of HRs and peripheral vascular resistance, most likely due to variable location of injury and the balance between disrupted efferent sympathetic and parasympathetic tone.
Empiric criteria for dx shock (Rosen’s box 3.2)
ill appearance or ams
heart rate >100
RR >20
arterial base defici t <-4 or paco2 <32
urine output <0.5
arterial hypotension >30 min duration (cont)
Broad strokes of treating shock
vitals
u/o (N >1ml/kg/h) vs reduced (.5-1ml/kg/h) or severe reduction (<0.5ml/kg/h)
confusion/ams
venous (>4) or base deficit (-4)
Useful labs to differentiate shock
cxr
ecg pocus
bg
cbc
urine
serum electrolytes
kidney and LFT
vbg vs abg
Sepsis defn
suspected or confimred infection with new or incr Sequential Organ Failure Assessment score of 2 from BL
Septic shock
sepsis
+ hypotension RQ vp after fluid loading plus lactate of >2
3 main stages of hemorrhagic shock
- simple hemorrhage
- hemorrhage with hypoperfusion
- hemorrhagic shock
Simple hemorrhage defn
suspected bleeding with HR <100, N RR, NBP, N base deficit
Hemorrhage with hypoperfusion defn
suspected bleeding with base deficit <-4 or persistent HR >100
Hemorrhagic shock defn
suspected bleeding with at least 4:
* Ill appearance or altered mental status
* Heart rate >100 beats/min
* Respiratory rate >20 breaths/min or Paco2 <32 mm Hg
* Arterial base deficit <−4 mEq/L or lactate level >4 mM/L
* Urine output <0.5 mL/kg/h
* Arterial hypotension >30 min duration, continuous
Cardiac failure
clinical evidence of impaired foward flow of heart, including presnece of sob, tachycardia, pulmonary edema, peripheral edema, and or cyanosis
Cardiogenic shock: defn
cardiac failure plus 4:
* Ill appearance or altered mental status
* Heart rate >100 beats/min
* Respiratory rate >20 breaths/min or Paco2 <32 mm Hg
* Arterial base deficit <−4 mEq/L or lactate level >4 mM/L
* Urine output <0.5 mL/kg/h
* Arterial hypotension >30 min duration, continuous
Sequential Organ Failure Assessment Score: 6 components
resp ratio pao2:fio2
cv MAP
coag (plt count)
renal (cr)
liver (total bili)
neuro (GCS)
Sequential Organ Failure Assessment Score: Resp ratio pao2/fio2 - score 0-4
0 - >400
301-400
201-300
101-200
</=100
Sequential Organ Failure Assessment Score: CV- score 0-4
0 - MAP >70
<70 without vp
dopamine </=5 mcg/kg/min or any dose of dopamine
> 5mcg/kg per min of dop or NE </= 0.1 mcg/kg/min or epi </=0.1 mcg/kg/min
NE >0.1 mcg/kg/min or epi >0.1mcg/kg/min or any dose vasopressin
Sequential Organ Failure Assessment Score: Coag/plt - score 0-4
0 - >150
100-149
50-00
20-49
<20
Sequential Organ Failure Assessment Score: renal - score 0-4
<1.2
1.2-1.9
2-3.4
3.5-4.9
>5
Sequential Organ Failure Assessment Score: total bili score 0-4
<1.2
1.2-1.9
2-5.9
6-11.9
>12
Sequential Organ Failure Assessment Score: GCS- score 0-4
15
13-14
10-12
6-9
<6
Name 8 variables indicating tissue hypoperfusion
hypotension
tachycardia
low CO
dusky/mottled skin
delayed cap refill
low u/o
low Central venous oxy sat
elevated lactate
AMS
Box 3.5: clinical management guidelines of hemorrhagic shock
- Ensure adequate ventilation and oxygenation.
- Provide immediate control of hemorrhage, when possible (e.g., traction for
long bone fractures, direct pressure, REBOA), and obtain urgent consulta-
tion as indicated for uncontrollable hemorrhage. - Initiate judicious infusion of isotonic crystalloid solution (10–20 mL/kg).
- Withevidenceofpoororganperfusionand30-minanticipateddelaytohem-
orrhage control, begin packed red blood cell (PRBC) infusion (5–10 mL/kg). - With suspected massive hemorrhage, immediate PRBC transfusion may be preferable as the initial resuscitation fluid, with balanced transfusions of
PRBCs, fresh frozen plasma, and platelets. - Treat coincident dysrhythmias.
Box 3.5: clinical management guidelines of cardiogenic shock
- Ameliorate increased work of breathing; provide oxygen and positive end- expiratory pressure (PEEP) for pulmonary edema.
- Begin vasopressor or inotropic support; norepinephrine (0.5 mcg/min) and dobutamine (5 mcg/kg/min) are common empirical agents.
- Seek to reverse the insult (e.g., thrombolysis, percutaneous transluminal angioplasty).
- Consider intraaortic balloon pump counterpulsation for refractory shock.
Box 3.5: clinical management guidelines of septic shock
- Ensure adequate oxygenation; remove work of breathing.
- Administer 30 mL of crystalloid/kg and titrate infusion based on dynamic
indices, volume responsiveness, and/or urine output. - Begin antimicrobial therapy; attempt surgical drainage or debridement.
- Begin PRBC infusion for hemoglobin level <7 g/dL.
- If volume restoration fails to improve organ perfusion, begin vasopressor
support with norepinephrine, infused at 0.5 mcg/min.
Best/most reasonable marker for Early goal directed resuscitation therapy?
Alternatively, lactate clearance refers to serial measurements of the venous or arterial lactate level. Lactate clearance has been shown to be equivalent to central venous oxygen saturation as an endpoint of early septic shock resuscitation, though it has not been systematically studied in other forms of shock.
If the lactate concen- tration has not decreased by __ - __% 2 hours after resuscitation has begun, additional steps are undertaken to improve systemic perfusion.
10% to 20%
Best gauge for resuscitation with vol?
18g
Initial vol replacement in ressu
isotonic crystalloid 20-25ml/kg
When to add vasopressors in vol resus?
persistent hypot despite 30ml/kg of IVF
When to transfuse in hemorrhagic shock or septic shock?
hemoglobin <7
If pt require more than _ units of PRBCs for hemorrhage, we recommend a balanced resuscitation using PRBCs, fresh-frozen plasma, and platelets in a 1:1:1 ratio, which is associated with better hemostasis and lower death due to exsanguination by 24 hours
2
Primary goal of vasopressors
incr CO and oxygen delivery to vital organs where crystalloid resus alone is inade
In patients who remain in shock after initial crystalloid boluses, norepinephrine should be initiated at a rate … and titrate…
of 0.05 mcg/kg/ min, or 3 to 5 mcg/min for most adult patients, and titrated at 3- to 5-minute intervals until the mean arterial pressure is greater than 65 mm Hg.
If BP still low after NE - add what vasopressor at what dose?
Vasopressin may be added as a second vasopressor agent, be initiated at 0.03 to 0.04 units/min, but there are no data that vasopressin alters outcomes.
when to use pheynlephrine?
if hypotension purely vasodil OR if tachydysr from NE
Intrope - dobutamine - what does this do?
inc CO and maintain O2 delivery in septic and cardiogenic shock
when to add dobutamine to septic shock?
if lactate does not decr by 10% at least despite fluid resus and vasopressor initial admin, dobutamin 2mcg/kg/min and titrate q5-10m in to max of 20
What adverse can dobutamine have in shock?
decr BP due to stim of vasodilating peripheral beta receptors
If simultaneous BP and contractility support necessary for sspetic shock - what med to use?
epinephrine alone, 0.2 mcg/kg/min starting dose, provides similar outcomes and adverse event rates as a combination of norepinephrine plus dobutamine.
. A 72-year-old male presents with crushing substernal chest pain with associated diaphoresis starting 2 hours prior to arrival. Blood pressure is 72/50. ECG shows anterior ST elevation myocardial infarction. Lungs demonstrate diffuse rales, and chest XR demon- strates bilateral infiltrates consistent with pulmonary edema. Bedside ultrasound demonstrates severely impaired left ven- tricular function. In addition to arranging for rapid reperfusion with either cardiac catheterization or intravenous thrombolytics, which is the most appropriate initial treatment for his cardiogenic shock?
a. Bolus of 30 mL/kg crystalloid fluid.
b. Initiate epinephrine at 0.1 mcg/kg/min.
c. Initiate norepinephrine at 0.1 mcg/kg/min.
d. Transfer patient for placement of an intraaortic balloon catheter.
c
A 56-year-old female presents with fever, dyspnea, and productive
cough. Heart rate is 122, respiratory rate is 24, and blood pressure is 82/46. Which of the following is the most appropriate choice for initial fluid resuscitation?
a. LactatedRingers.
b. Blood products.
c. Hydroxyethyl starch (HES).
d. Normal Saline.
a
An 18-year-old unrestrained driver is transported to the emer-
gency department (ED) after being thrown from his vehicle during a motor vehicle collision. He was intubated in the field and received an intravascular bolus of 3 L of normal saline before arrival to the ED. His initial Glasgow Coma Score (GCS) is 7, and his blood pressure on arrival is 80/50 mm Hg. Which of the fol- lowing would be the most appropriate to initiate immediately on arrival to the ED?
a. Dobutamine.
b. Dopamine.
c. Norepinephrine.
d. Packed red blood cell (PRBC) transfusion.
d
