Head Injuries and Drowning ~ Trauma

what is the formula for CPP? what is the normal

cerebral perfusion pressure = MAP - ICP

normal is 60

what is within the skull

brain

blood

CSF

what can happen in some cases where the pressure in the skull gets too high

example is severe head injuries

it can herniate down the fossa at the posterior base of the skull causing brain herniation. which can cause brain death

if CPP is lower, then the ICP is not much lower than MAP, what does this mean for the brain

the brain is not being perfused, cerebral ishcemia will result

what is an epidural hematoma

blood accumulates between the dura mater and the posterior wall of the skull  

also blood vessels within the space as well as the temporal or parietal areas of the brain

what is a subdural hematoma? is it worse than a epidural hematoma?

subdural is worse than an epidural hematoma

it is the collection of blood between the dura mater nad arachnoid matter

also shearing of blood vessels (blood curve to conform to the shape of the brain)

what is a subarachnoid hematoma

bleeding under the arachnoid matter of the brain

can get smaller or larger in size over time

what is diffuse axonal injury; is there treatment?

nerve injury due to shearing and there is no effective treatment at this time

why is short period of hypoxia significant in head injuried

saturation <90% for 15 - 20 minutes is an independent predictor of death

what does increased CO2 do to the brain

causes vasodilation and increase blood flow to the brain

what does decreased CO2 do to the brain

causes vasoconstriction and decreased blood flow to the brain.

how does hyperventilation help head injuries

CO2 <25 causes rapid reduction of ICP and risk making anoxic episode worse. CO2 should be within 35 - 45 to minimize risk of increasing ICP

what ventilator strategies are used in head injury patients

ARDSnet

why hypotension to be monitored in head injuries

a single episode of systolic BP <90 can increase mortality and morbidity

if the MAP is low, ICP is high

brain ischemia

what is the best score in glascow coma score

15

what is the good score for glascow coma scale

13

what is deep coma/death in glascow coma scale

3

what is the baseline for assessing head injuries

thorough neurological exam

what are ways to reduce ICP

• sedation

• hypothermia to minimize metabolism

• hypersmolar solutions

  • mannitol (can cause hypotension)

  • hypertonic saline

• surgery

• intracranial oxygen monitoring

• low stimulation environment

what is the drowning sequence

1. panic struggle

2. calm with apnea

3. swallowing fluid then vomiting

4. gasping and aspiration

5. convulsions

6. coma

7. death

what is the 3rd cause of accidental death

drowning in the United States

what is the 2nd cause of accidental death of those 5 and 44 years old

drowning

what is drowning

suffocation and death as a result of submersion in water

what are other terms of drowning? what does wet and dry drowing mean

• dry ~ no water found in lungs

• wet ~ water found in lungs

• salt water

• fresh water

• cold water

what is there to note about cold water drowing

outcomes are better, especially when the person is young and submerged in water for a short period of time, and water is cold and clean

how many percent of kids under the age of 4 die due to drowing

40%

when do symptoms show up in secondary drowing

more than 24 hours after event

what is the pulmonary sequence of drowing

• laryngospasm

• mammalian diving reflex

• interstitial edema

• decreased surfactant

• pulmonary edema

• atelectasis

• consolidation

• bronchospasm

what does laryngospasm do in drowing

keeps water from entering the lungs for a short period of time

larynx relaxes , allowing water to enter the lungs.

what is the mammalian diving reflex

putting a persons face in cold water, it activates the parasympathetic nervous system and is also used for vagal responses. can be used during tachyarrthmia

what does fresh water cause

hemolysis

decrease sodium

depletes surfactant

what does salt water cause

draws water from bloodstream and pulmonary edema occurs

what are the clinical findings in drowning

• apnea or tachypnea

• asystole or tachycardia

• cyanosis

• pulmonary edema

• crackles and wheezes

what are the PFT of a drowning pt

restrictive pattern

what would the ABG of a drowing pt show

mixed acidosis with hypoxemia

what would the radiology of a drowing pt show

normal to extensive edema with atelectasis

what is the general management for drowning

prevention (main management)

• learn to swim

• fencing around pool

• watch kids in pools, toilets, and baths

support BP

warming

ECMO?

intubate and ventilation

how to warm drowning pts

warm them inside out with fluids and warm air

what are potential complications of drowning

• anoxic damage

• seizures

• watch blood glucose

• respiratory failure and infections (surfactant replacements)

• hypotension

• hypoxic cardiomyopathies

what infection are drowning pts at risk of

pneumonia