N430 - Unit 4

1.5-6 mmHg

normal ICP for infants

3-7 mmHg

normal ICP for children

5-15 mmHg

normal ICP for adults

increased ICP

ICP of 15 mmHg or higher in adults

severely increased ICP

ICP greater than 20 mmHg in adults

cerebrum

largest portion of the brain; contains:

• frontal lobe

• parietal lobe

• occipital lobe

• temporal lobe

frontal lobe

responsible for speech, emotions, involuntary movements, thoughts, judgement

parietal lobe

responsible for shape recognition, pain, temperature regulation

occipital lobe

responsible for visual interpretation

temporal lobe

stores memory and interprets auditory stimuli

Broca’s area

area of the brain responsible for speech production

Wernicke’s area

area of the brain responsible for language development and speech comprehension

cerebellum

second largest part of brain; contains gray & white matter

functions:

• skeletal muscle coordination

• smooth muscle movement

• balance

diencephalon

contains:

• thalamus

• hypothalamus

• epithalamus

thalamus

gateway to the cerebral cortex

hypothalamus

autonomic control center of several body functions (ex: mood, sleep cycle)

epithalamus

connects the limbic system to other parts of the brain

contains pineal gland that helps secrete melatonin

brainstem

connects pathways, influences BP, regulates respiratory rate/depth/rhythm; contains:

• midbrain

• pons

• medulla oblongata

seizure

period of abnormal electrical discharge in the brain

status epilepticus

continuous seizure that lasts more than 5 minutes or a series of seizures without regaining consciousness between

2 years

how long must a patient be seizure free to consider trialing weaning off of seizure medications

Monro-Kelle hypothesis

relationship between the following three components: brain matter (80%), blood (10%) and CSF (10%)

cerebral perfusion pressure (CPP)

= MAP-ICP

• normal: 50-100 mmHg

Cushing’s triad

indicates increased ICP

1. bradycardia

2. irregular respirations (Cheyne-Stokes)

3. widened pulse pressure

ventriculostomy drain

what is the best way to assess ICP?

basilar skull fracture

what type of skull fracture contraindicates insertion of an NG tube?

airway

A of ABCDE

breathing

B of ABCDE

circulation

C of ABCDE

disability/neuro assessment

D of ABCDE

exposure/environmental control

E of ABCDE

permissive hypotension

allows vasoconstriction to shunt blood to the organs

Beck’s triad

sign of cardiac tamponade

1. JVD

2. muffled heart tones

3. hypotension

Cullen’s sign

bruising around the umbilicus

may indicate internal bleeding d/t blunt abdominal trauma

Grey Turner’s sign

bruising near the peritoneum or back

Kehr’s sign

referred L) shoulder pain d/t blood irritation in peritoneal cavity

may indicate splenic injury

multiple organ dysfunction syndrome (MODS)

the progresive dysfunction of two or more organ systems that occurs as a result of uncontrolled inflammation from severe illness or injury

• uncontrolled systemic inflammation

• tissue hypoxia

• unregulated cell death

• microvascular coagulopathy

what are the 4 pathophysiologic consequences of MODS?

primary MODS

direct consequence of an initiating event (develops w/n first 72 hours)

risk factors:

• severity of injury

• shock

• SIRS

secondary MODS

may occur weeks after initial injury

risk factors:

• infection

• multiple transfusions

• multiple surgical procedures

at 24 hours

during what time frame are the following manifestations likely to occur?

• low-grade fever

• tachycardia

• tachypnea/dyspnea

• AMS

• general hyperdynamic & hypermetabolic state

at 24-72 hours

during what time frame are the following manifestations likely to occur?

• lung failure begins

• ARDS possible

days 7-10

during what time frame are the following manifestations likely to occur?

• hepatic failure develops

• renal failure develops

• intestinal failure develops

days 14-21

during what time frame are the following manifestations likely to occur?

• increased severity of renal failure

• increased severity of liver failure

• hematologic failure

• myocardial failure

• possible occurence of death

sequential organ failure assessment (SOFA)

assessment tool which includes the six major organ systems and tracks a patient’s organ function or failure

1. respiratory

2. cardiovascular

3. hepatic

4. coagulation

5. renal

6. neurological

causes hypotension

how does MODS affect the cardiovascular system and blood pressure

decerebrate

extension posturing

decorticate

abnormal flexion posturing

rancho los amigos scale

scale used to diagnose symptoms of TBIs; measures levels of awareness, cognition, behavior, and interaction with the environment

thrombocytopenia

decreased platelets; most common hematologic dysfunction in MODS

mechanical ventilation

treatment for the respiratory system in MODS

enteral feedings, hyperalimentation, tight glucose control

treatment for GI system in MODS

dialysis or CRRT

treatment for renal system in MODS

inotropic drugs, vasopressors

treatment for cardiovascular system in MODS

stage 1 of shock

initial/early

• baroreceptors detect from in MAP <10 mmHg

• subclinical manifestations

• tissue perfusion maintained

stage 2 of shock

compensatory stage (after MAP falls 10-15 mmHg)

• neural compensation

• hormonal compensation

• chemical compensation

stage 3 of shock

decompensated/progressive shock (after MAP falls 20 mmHg or more)

• increased anaerobic metabolism (+ lactic acid formation)

• failure of Na/K pump (cells swell)

• increased HR, workload, O2 demand

• increased vasoconstriction (decreased organ perfusion)

• brain & heart more hypoxic

stage 4 of shock

refractory shock (irreversible)

• generalized tissue anoxia

• cellular death

• untreatable

arterial line

continuous BP monitoring, allows for access for blood draws

pulmonary artery catheter

assesses hemodynamic parameters to improve cardiac function

• preload

• afterload

• contractility

central venous catheter

central access for IV fluids & medications, capable of monitoring SVO2

hypovolemic shock

any condition that reduces the volume within the vascular compartment by 15% or more

most common form of shock!

causes:

• hemorrhage

• severe burns

• emesis/diarrhea with loss of fluids & electrolytes

• third spacing

cardiogenic shock

inability of the heart to pump sufficient blood to perfuse cells of the body (pump failure)

causes:

• MI

• restrictive pericarditis

• dysrhythmias

• cardiomyopathies

• electrolyte imbalances

• chest/heart trauma

• pulsus paradoxus (Beck’s triad)

hypovolemic

low CVP and PAWP (ventricular preload) are signs of which type of shock?

cardiogenic

increased CVP and PAWP (ventricular preload) are signs of which type of shock?

intraaortic balloon pump

device used to decrease afterload and myocardial workload, and increase coronary artery perfusion

- diastole (inflates)

- systole (deflates prior to)

Impella pump

device that supports a failing heart by decreasing myocardial workload

ventricular assist devices

devices used as a short-term mechanism to rest the injured myocardium when CABG is not an option

acts as a bridge to transplantation

extracorporeal membrane oxygenation (ECMO)

machine that supports respiratory and cardiac function

distributive shock

massive dilation of the blood vessels resulting in disproportion between the size of the vascular space and the amount of blood contained in it

3 types: neurogenic, anaphylactic, and septic

neurogenic shock

imbalance between the parasympathetic and sympathetic vascular tone → massive vasodilation

causes:

• spinal cord injury

• increased levels of spinal anesthesia

• brain damage

• stress

• pain

• drug overdose

low SVR (afterload)

what is the clinical hallmark manifestation of neurogenic shock?

other symptoms: bradycardia, hypotension, decreased CVP, syncope

anaphylactic shock

life-threatening systemic hypersensitivity reaction characterized by massive vasodilation and increased capillary permeability

epinephrine

which drug is given for the treatment of anaphylactic shock that decreases degranulation, reverses airway constriction & vasoconstriction

septic shock

life-threatening organ dysfunction caused by a deregulated host response to infection

most common form of distributive shock!

predisposing conditions:

• very old/very young

• immunosuppression, chronic illness

• GU/GI surgery

• poor nutrition

• use of invasive devices

• pregnancy

disseminated intravascular coagulopathy (DIC)

hematological disorder most commonly caused by sepsis

2 stages:

1. clotting/thrombotic stage

2. bleeding stage

the lungs

which organ is often the first to fail in MODS