Shock Flashcards
Regardless of “type” of shock, there is an inability to obtain or utilize what?
O2 in sufficient quantities to meet metabolic requirements; from compromised CO &/or BP
Shock causes what demand and supply imbalance?
demand > supply
Shock is most often from changes in O2 delivery; as delivery decreases, extraction increases as compensatory mechanism.
What is a normal extraction ratio?
What is the maximal extraction ratio?
20%
60%
As O2 delivery decreases, extraction eventually decreases (point of critical O2 delivery) leading to what?
Dysoxia (o2 debt), anaerobic metabolism/lactic acidosis leading to
cellular dysfunction leading to
Organ dysfunction leading to
death
What is cytopathic hypoxia?
adequate O2 delivery but inability to use O2 d/t mitochondrial dysfunction (sepsis) which is mediated by inflammatory cytokines and NO
O2 delivery equation
DO2 =?
Example question
Hb = 12.3
SaO2 = 98%
CO = 3.5
[1.39 x Hb x SaO2] x CO x 10
586.4 ml O2/min
CNS complications of shock?
Encephalopathy
Cardiac Complications of shock?
Tachycardia
Decreased coronary artery perfusion, possible ischemia
Myocardial depression
Respiratory Complications of shock?
Increased MV resulting in hypocapnia & respiratory alkalosis
Increased ventilation/perfusion mismatch
Respiratory failure d/t increased workload, muscle impairment
ARDS
Renal Complications of shock?
ARF secondary to ATN from hypoperfusion
GI Complications of shock?
Ileus
Erosive gastritis
Pancreatitis
Acalculous cholecystitis
Submucosal hemorrhage
Bacterial translocation d/t ischemia
Liver Complications of shock?
“shock liver” is atypical in absence of hepatocellular dz or very severe injury
Mild elevations of LFTs, bili, alk phos more common
Impaired synthetic fxn - decreased albumin, coag factors
Hematologic Complications of shock?
DIC
Dilutional thrombocytopenia following resuscitation
Metabolic Complications of shock?
Hyperglycemia d/t increased ACTH, glucocorticoids, glucagon
Decreased insulin release results in glycogenolysis, gluconeogenesis
Immunologic Complications of shock?
Immune dysfunction d/t mucosal injury
Decreased T& B lymphocytes
Compensatory Mechanisms of Shock
Maintenance of MAP
Fluid redistribution to vascular space
Decreased Renal losses
Increased sympathetic activity
Increased adrenal epi
Increased angiotensin
Compensatory Mechanisms of Shock
Maintenance of MAP
Where does Fluid redistribution to vascular space come from?
From interstitium
from intracellular space
Compensatory Mechanisms of Shock
Maintenance of MAP
Decreased Renal losses occurs because of?
decreased GFR
Increased aldosterone from adrenals
increased vasopressin from pituitary
Compensatory Mechanisms of Shock
Cardiac performance
increased contractility d/t
sympathetic stimulation
adrenal stimulation
Compensatory Mechanisms of Shock
Perfusion distribution
Extrinsic regulation of arterial tone systemically
Autoregulation of vital organs
Compensatory Mechanisms of Shock
O2 unloading
Increased RBC 2,3-diphophoglycerate
decreased tissue PO2
tissue acidosis
pyrexia
2,3-diphosphoglycerate has what effect on Hemoglobin-O2 dissociation curve?
Shifts it to the R increasing O2 offloading at the level of tissue
Classifications of Shock
Hypodynamic:
Low CO
Narrow pulse pressure
Classifications of Shock
Hypodynamic Types of shock?
Hypovolemia (hemorrhage)
Cardiogenic (acute MI)
Obstructive (PE, tamponade, tension PTX)
Classifications of Shock
Hyperdynamic aka distributive or vasodilatory:
Low SVR
Widened Pulse pressure
Classifications of Shock
Hyperdynamic aka distributive or vasodilatory types of shock?
Sepsis
Anaphylaxis
Liver failure
Neurogenic
Hypovolemic shock occurs d/t what?
Decreased ventricular preload
Hypovolemic shock types?
Hemorrhagic
Non-hemorrhagic
Venodilation
Hypovolemic shock
Hemorrhagic occurs from?
Trauma
GI Bleed
RP bleed
Hypovolemic shock
Non-hemorrhagic occurs from?
dehydration
vomiting/diarrhea
polyurea
thermal injury
anaphylaxis
Hypovolemic shock
Venodilation occurs from?
Sepsis
Anaphylaxis
Toxins/drugs
Cardiogenic aka decreased pump function shock types are?
Myopathic
Mechanical
Arrhythmias
Cardiogenic aka decreased pump function
Myopathic occurs from?
MI (LV or RV)
myocardial contusion
myocarditis
CM
Post-ischemic stunning
Septic myocardial depression
meds (CCB)
Cardiogenic aka decreased pump function
Mechanical occurs from?
valvular d/os (stesnosis, regurg)
Hypertrophic CM
VSD
Cardiogenic aka decreased pump function
Arrhythmias occur from?
brady/tachycardias
Obstructive - obstruction of flow in CV circuit types are?
impaired diastolic filling
Impaired systolic contraction / increased afterload
Obstructive - obstruction of flow in CV circuit
Impaired Diastolic Filling occurs from?
Tension PTX
MV w/ PEEP, volume depletion
Constrictive pericarditis
Cardiac tamponade
Obstructive - obstruction of flow in CV circuit
Impaired systolic contraction / increased afterload occurs from?
PE
Acute pulm HTN
Aortic dissection
Distributive - loss of peripheral resistance types are?
sepsis (most common cause)
Toxic Shock
Anaphylaxis
Neurogenic
Thyroid storm
Toxic (nipride)
General Clinical Presentation of shock?
Tachycardia
Tachypnea
Cyanosis
Oliguria
Encephalopathy
Mottling
Hypotension (SBP < 90 mmHg)
-
Clinical Presentation (hypovolemic shock)
Hypodynamic
Orthostatic hypotension
Dizziness
Tachycardia
A fib (elderly)
Collapsed peripheral veins
Decreased body temp (elderly)
Cold, clammy skin
Tachypnea
Oliguria
Peripheral cyanosis
Clinical Presentation (cardiogenic shock)
Hypodynamic
Ashen or cyanotic
Cool skin
Mottled extremities
Decreased MS
Rapid, weak pulse
JVD
Crackles
Palpable precordial heave
S3 or S4
Clinical Presentation (Obstructive shock - tamponade)
Hypodynamic
Dyspnea
JVD
Hypotension
Muffled heart sounds
Pulsus Paradoxus (inspiratory fall in SBP > 10 mmHg d/t decreased LV volume on inspiration)
Cool, clammy skin
Tachycardia
Clinical Presentation (Obstructive shock - tension PTX)
Hypodynamic
Chest pain
Dyspnea
Tachycardia
Tachypnea
Decreased breath sounds, hyperresonance on affected side
JVD
Clinical Presentation (Obstructive shock - PE)
Hypodynamic
Tachycardia
Dyspnea
Hypotension
Chest Pain
Hemoptysis
Clinical Presentation (distributive shock - sepsis)
Hyperdynamic
Fever or hypothermic
Tachycardia
Tachypnea
Hypotension (SBP < 90 mmHg)
Warm or cold extremities
Clinical Presentation (distributive shock - neurogenic)
Hyperdynamic
Bradycardia
Warm extremities
Bounding pulses
Lab Studies to collect with shock state?
WBC count
Hb
Plt count
ABG
BUN/Cr
ECG
Lactate
Central Venous O2 saturation
Why collect WBC count in shock state?
often elevated early
may be decreased in sepsis & late shock
Why collect Hb in shock state?
May be elevated in non-hemorrhagic, hypovolemic shock, septic shock d/t extravasation
Why collect plt count in shock state?
may be elevated early
decreased w/ sepsis, hemorrhage
Why collect ABG in shock state?
anion gap acidosis w/ elevated lactate
Why collect BUN/Cr in shock state?
BUN may be elevated if GI blood loss, hypovolemia
Elevated creatinine w/ ongoing decreased tissue perfusion
Why collect EKG in shock state?
To evaluate for cardiac ischemia in cardiogenic shock or secondary to other shock
R heart strain/R axis deviation, RBBB in PE
Why collect Lactate in shock state?
Relatively late marker of decreased tissue perfusion/oxygenation
Cleared by liver; may be elevated in liver failure
Serial levels can be used as markers of adequacy of resuscitation
What imaging should be collected for shock state?
CXR
CT scan if suspect hemorrhage, PE, Sepsis
US (RUSH exam)
VQ scan if suspect PE
Why get a CXR in shock state?
Infiltrates in septic shock
Pulmonary Edema in cardiogenic shock
PTX
Cardiac tamponade (obstructive shock)
HD monitoring in shock state can include?
Arterial catheter
CVP
PAC
Esophageal doppler
Why monitor CVP in shock state?
May be useful in otherwise healthy patients
may differentiate b/t different forms of shock (low in hypovolemia, high in cardiogenic shock)
SvO2 is low w/ decreased O2 delivery w/ what conditions?
decreased Hb
Decreased CO
Decreased saturation
SvO2 is low w/ increased O2 extraction occurs from?
fever
shivering
seizures
SvO2 is elevated w/ maldistribution of blood flow from?
sepsis
Hemodynamic Profiles
Hypovolemic Shock
Decreased CO
Increased SVR
Decreased PWP
Decreased CVP
Decreased SvO2
Hemodynamic Profiles
Cardiogenic from Mi, MR, RV infarction
Decreased CO
Increased SVR
Increased PWP
Increased CVP
Decreased SvO2
Hemodynamic Profiles
Obstructive (cardiac tamponade)
Decreased CO
Increased SVR
Increased PWP
Increased CVP
Decreased SvO2
Hemodynamic Profiles
Obstructive (massive PE)
Decreased CO
Increased SVR
NL or low PWP
Increased CVP
Decreased SvO2
Hemodynamic Profiles
Distributive (sepsis, anaphylaxis)
NL or elevated CO
Decreased SVR
NL or low PWP
NL or low CVP
Elevated SvO2
Management of Shock
Depends on what?
but goal is the same which is?
underlying pathology
prompt restoration of perfusion to vital organs & tissues before cellular injury ensues
Management of Shock
Goal of volume?
Increase stroke volume/SVO
Management of Shock
General management goals
BP support (>60-65 mmHg)
CI > 2.1 L/min/m squared (cardiogenic & obstructive)
Lactate Level < 2.2 mmol/L
ScvO2 > 70% (sepsis)
Fluid resuscitation < 6hrs (sepsis)
Antibiotics < 1hr (sepsis)
Stroke Volume Optimization
Indications
age
HF
Low UOP
Bleeding
Monitoring fluid boluses/vasopressors
Cardiac conditions
risk of hypoperfusion
Stroke Volume Optimization
Methods
Noninvasive doppler imaging
Esophageal doppler imaging
Bioimpedence
Endotracheally applied bioimpedence
Pulse coutour
Exhaled CO2
PAC
HD parameters Reference range
CO
4-8 L/min
HD parameters Reference range
Stroke Volume
50-100 ml
HD parameters Reference range
Stroke Index
25-45
HD parameters Reference range
Flow time corrected (FTc)
330-360 ms
HD parameters Reference range
Peak velocity
30-120 cm/s
HD parameters Reference range
Stroke distance
10-20
HD parameters Reference range
CI
2.8-4.2
HD parameters Reference range
SVR
900-1600 dyne sec cm
HD parameters Reference range
ScvO2
65-80
HD parameters Reference range
CVP
2-8 mmHg
HD parameters Reference range
Stroke volume variation
< 10-15%
SVO
With Low SV or FTc do what?
Give 200 ml colloid or 500 ml crystalloid
SVO
If after giving 200 ml colloid or 500 ml crystalloid the SV increased < 10% do what?
If SV increases > 10% do what?
stop giving fluids
Give additional volume
Hypovolemic shock
Goals?
Rapid restoration of circulating volume, tx underlying cause
Hypovolemic Shock
Support needed?
Access required?
Resuscitation is done w/?
Airway/breathing
2 large bore IVs
Isotonic (LR or NS), blood products if hemorrhage
Hypovolemic Shock
Lab studies to obtain?
CBC
T&C
Electrolytes
renal fxn
ABG
Lactate
Coagulation
ScvO2
Cardiogenic Shock
Treat underlying cause
Support what?
Fluid resuscitation?
Pressors for what?
Inotropic agents for what?
IABP to reduce what? & Optimize what?
Thrombolytics, revascularization
airway/breathing
Predetermined boluses per Starling curve unless frank pulmonary edema present
hypotension despite fluid resuscitation
inadequate perfusion & adequate intravascular volume
afterload; diastolic perfusion pressures
Dopamine
Dose
MOA
Notes?
5-15mcg/kg/min
Increased HR, Contractility, CI (beta adrenergic), BP (alpha)
May cause tachycardia/exacerbate ischemia
Norepinephrine
Dose
MOA
Notes?
0.01-3 mcg/kg/min
Increased BP & SVR (alpha), increased splanchnic perfusion (beta), Increased HR
none
Phenylephrine
Dose
MOA
Notes?
40-180 mcg/kg/min
Increased BP & SVR (alpha), decreased HR
May be useful if tachycardia; caution if reduced cardiac function
Epinephrine
Dose
MOA
Notes?
0.1-0.8 mcg/kg/min
Increased BP, CI, SV, HR (alpha & beta)
For those refractor to fluid resuscitation or other vasopressors, decreased splanchnic perfusion
Dobutamine
Dose
MOA
Notes?
2-20 mcg/kg/min
Increased contractility & CO (beta)
May exacerbate hypotension and precipitate arrhythmias
Milrinone
Dose
MOA
Notes?
0.375 - 0.75 mcg/kg/min
Obstructive Shock
Support what?
Tx underlying pathology such as?
Fluid resuscitation?
Meds to use?
airway breathing
needle thoracentisis, chest tube (PTX), pericardiocentesis (tamponade), anticoagulation (PE)
Yes
Inotropes
Distributive shock
Support what?
Tx what?
Fluid resuscitation goal?
Vasopressors to use?
Surviving ____ campaign
Epinephrine dose for anaphylaxis?
airway/breathing
underlying cause
CVP 8-12, MAP >/= 65, UOP >/= 0.5 ml/kg/h, mixed venous O2 sat > 65%
Levo, Epi, Vaso
Sepsis
0.3-0.5 ml 1:1000 solution SC or IM q 15 min prn