Mechin isms of Brain injury
primary injury is that which occurs immediately
at the onset of brain injury Meaning that there is
little that can be done to reverse the process once
It has occurred Ex with head trauma some tissues
will be irreversibly damaged at the time of impact causing
mechanical forces such as shearing tearing stretching of
neurons etc
Secondary injury development of further
the
neurologic damage and changes subsequent to the
primary injury these may progress over days and
weeks and continue to cause changes to the brain for
years As the brain starts to have
cerebral edema swelling up as the
brain might have brusing and bleeding
we will see these secondary injuries
Vascular compromise Perfusion Circulation issues
Reperfusion injury '
Abnormal auto regulation
Blood flow through the brain tissue is controlled
, g
by autoregulation of pHCO2 and oxygen levels
Hypotension predisposes to ischemia whereas severe
hypertension may lead to vascular damage and brain edema
Anything that interferes with the ability of the
Vessels to dilate can lead to ischemia
Increased CO2 causes vasodilation
Decreased CO2 Causes vasoconstriction
DeCreasey IncreasedCoz
T T
Fa
t patientisbreath Éognagathtfeitrharinfreespiratory
toofastthereblowingoff depressionsothecozgoesupbecause
theirCO2Causinghypertension theholdingontotheircozcausing
Hypotension
ATP level reduction is a consequence of ischemia
me
and hypoxia which accompanymany types of acute brain injury
i
including trauma and stroke
Ischemia decreased blood flow
Hypoxia defiency of oxygen at a cellular level
Mitocondria Failure
primary injury is that which occurs immediately
at the onset of brain injury Meaning that there is
little that can be done to reverse the process once
It has occurred Ex with head trauma some tissues
will be irreversibly damaged at the time of impact causing
mechanical forces such as shearing tearing stretching of
neurons etc
Secondary injury development of further
the
neurologic damage and changes subsequent to the
primary injury these may progress over days and
weeks and continue to cause changes to the brain for
years As the brain starts to have
cerebral edema swelling up as the
brain might have brusing and bleeding
we will see these secondary injuries
Vascular compromise Perfusion Circulation issues
Reperfusion injury '
Abnormal auto regulation
Blood flow through the brain tissue is controlled
, g
by autoregulation of pHCO2 and oxygen levels
Hypotension predisposes to ischemia whereas severe
hypertension may lead to vascular damage and brain edema
Anything that interferes with the ability of the
Vessels to dilate can lead to ischemia
Increased CO2 causes vasodilation
Decreased CO2 Causes vasoconstriction
DeCreasey IncreasedCoz
T T
Fa
t patientisbreath Éognagathtfeitrharinfreespiratory
toofastthereblowingoff depressionsothecozgoesupbecause
theirCO2Causinghypertension theholdingontotheircozcausing
Hypotension
ATP level reduction is a consequence of ischemia
me
and hypoxia which accompanymany types of acute brain injury
i
including trauma and stroke
Ischemia decreased blood flow
Hypoxia defiency of oxygen at a cellular level
Mitocondria Failure
