MILD HEAD INJURY (MHI)

download report

Transcript MILD HEAD INJURY (MHI)

MILD HEAD INJURY (MHI)
Bernard Foley
Auckland Hospital
Emergency Department
6th October 2001
SCENARIO 1
A 15-year-old boy is brought to your clinic by
his mother
He had been out rollerblading and was
observed to fall and hit his head
He was not knocked out
He complains of mild headache
SCENARIO 2
A 23-year-old man presents by ambulance
He had been drinking at a pub and
subsequently assaulted 1 hour ago
GCS 14, PERLA, No focal neurology or signs
of skull fracture
SCENARIO 3
A 45-year-old woman presents following an
RTC
Briefly K.O.’D at the scene
GCS 12 (E3,M5,V4)
PERLA
No focal neurology
Large haematoma over right temple region
MHI EPIDEMIOLOGY
@ 130 MILD HEAD INJURIES/100,000/yr.
@ 100/MONTH AT AUCKLAND ED
MALE 2 : 1 FEMALE
PEAK AGE 15-24 YEARS
LOWEST RATES AGE 35-65
ALCOHOL > 17mmol/L PRESENT IN 2/3rds
OF THOSE TESTED FOR IT
MHI CAUSES
ROAD CRASH
FALLS
ASSAULT
SPORTS
40%
20%
15%
12%
CHILDREN CONSIDER NAI
MHI DIAGNOSES
CONCUSSION
FACIAL/SKULL FRACTURE
CONTUSION
HAEMORRHAGE
80%
10%
5%
1%
CONCUSSION
Transient alteration in cerebral function
Usually associated with L.O.C.
Thought to be due to disturbance in reticular
activating system function
No structural brain injury
May lead to post-concussive syndromes
POST CONCUSSION SYMDROMES
Typically mild headache and cognitive
disturbances
Confusion,nausea,dizziness,fatigue
Typically last 1-2 days
May last months
If symptoms last >6 weeks should be seen by
head injury specialist
CONTUSION
Bruising of brain substance
Morbidity relates to size and site of contusion
Commonly occur in frontal and temporal lobes
INTRACRANIAL BLEEDING
Extradural
Subdural
Intracerebral
Subarachnoid
Intraventricular
DIFFUSE AXONAL INJURY
Shearing and rotational forces resulting in
major structural and functional damage at a
microscopic level.
CT scan often appears normal
Pathogenesis unclear
MINIMAL HEAD INJURY
GCS 15 and…
No or only mild headache and nausea
No L.O.C.
No antegrade amnesia
No seizure
No vomiting
2< AGE< 65
Likelihood of CT abnormality essentially 0%
MILD HEAD INJURY
GCS 14 or 15 and….
Any L.O.C., seizure or vomiting
Intoxication, Coagulopathy
Clinical skull fracture or large scalp
haematoma
Focal neurological abnormality
Abnormal pupillary reactions
MILD HEAD INJURY 2
Likelihood of abnormal CT @ 10%
Neurosurgical intervention <1%
MODERATE HEAD INJURY
GCS 9-13
Likelihood of abnormal CT 40%
Neurosurgical intervention @ 8%
Mortality 20%
Long term disability 50%
SEVERE HEAD INJURY
GCS <9
Mortality 40%
Long term disability >90%
HISTORY
Accident events
Duration of L.O.C.
Seizure?
Amnesia
Nausea/vomiting
Drug use
Coexistent medical problems/allergies etc.
PHYSICAL EXAMINATION
Primary survey
GCS
Check/protect C-spine
Pupils
Signs of skull/ basal skull fracture
Focal neurology
Other injuries
NEUROLOGICAL OBSERVATIONS
No good evidence of usefulness
No evidence regarding duration
4-hours v 24-hours
Possibly useful if no imaging available
INVESTIGATIONS
Blood tests
Consider Glucose, U&E’s, FBC, Group and Hold
Skull x-rays
No
Perhaps in suspected depressed skull fracture
CT head
Investigation of choice
Considerable debate about who should be scanned
CT HEAD - PRO’S
ACCURATE DIAGNOSIS OF
INTRACRANIAL INJURY
AIDS SURGICAL PLANNING/ TRIAGE
MAY IDENTIFY AREAS WHERE INJURY
OTHERWISE OCCULT
MAY IDENTIFY INJURY WHERE NOT
SUSPECTED
MOST STUDIES IN LEVEL 1 TRAUMA CENTRES
CT HEAD CONS
EXPENSE
AVAILABILITY
MAY REQUIRE TRANSPORT TO ANOTHER
FACILITY
RADIATION EXPOSURE
PATIENT ISOLATION
?SEDATION REQUIRED esp. KIDS
CANADIAN CT HEAD RULES
LANCET 2001;357 1391-96
ELIGIBILITY
Blunt trauma within 24 hours
Witnessed L.O.C. or definite amnesia or
disorientation
GCS 13 or greater
EXCLUSIONS
Obvious penetrating injury, depressed skull
fracture or focal neurology on exam
CANADIAN HEAD CT RULES
5 HIGH RISK PREDICTORS
1) GCS < 15, 2 hours after injury
2) Suspected open or depressed skull fracture
3) Any sign of basal skull fracture
4) Vomiting (2x or more)
5) Age > 65
CANADIAN HEAD CT RULES
2 Additional medium risk factors
Amnesia >30 minutes before event
Dangerous mechanism of injury
Fall > 3 feet or 5 stairs
Pedestrian struck by motor vehicle
Ejected from car
CANADIAN HEAD CT RULES
USING 5 HIGH-RISK CRITERIA
100% sensitivity (identifying those dying or
requiring neurosurgery
Specificity 69%
USING ABOVE + 2 MEDIUM RISK
CRITERIA
98.4% sensitivity and 54% specificity
WHO TO SCAN
AGE > 65
INTOXICATED
SEVERE HEADACHE
VOMITING
SEIZURE
SIGNS OF SKULL FRACTURE
FOCAL NEUROLOGY
? ALL LATE PRESENTERS
MANAGEMENT
Analgesia
Attend to other injuries
? Tetanus prophylaxis
? Observation
Referral if requires inpatient care
Documentation (incl.. ACC)
MANAGEMENT (SEVERE INJURY)
Discuss with hospital/neurosurgeon
Oxygen/ ? Intubate and ventilate
IV access
Treat hypotension with fluids
Protect spine
Consider neuroprotection
Role of mannitol and hyperventilation
controversial
DISCHARGE
ALL MINIMAL HEAD INJURY
If sober and competent observer
ALL MHI WITH NORMAL CT SCAN
Unless other injuries
All require competent supervision
ADMIT ALL MODERATE/SEVERE
ADMIT ALL WITH ABNORMAL CT
DISCHARGE ADVICE
Written advice
Explain and give to observer
67% will carry out instructions correctly
If given to patient to arrange <20%
ANNALS OF EMRGENCY MEDICINE
15:2 FEB 1986
DISCHARGE ADVICE
EXPLAIN POST CONCUSSION
SYMPTOMS
REST AND TIME OFF WORK
ANALGESIA
RETURN IF ANY CONCERNS
AVOID
Alcohol
Driving? Major decisions for 24 hours
Further injury for 3 weeks