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