Acute Head Injuries in the Intensive Care Unit

Suzanne Gough

Content

• Types of head injury • Implications of acute head injury• Aims of medical treatment• Cerebral perfusion pressure• Intra-cranial pressure• Monitoring ICP• Management of ICP• Physiotherapy management

Normal brain

Epidemiology – Head Injuries• 1,000,000 hospitalised /year as of result head injuries

(HI)• 150,000 – minor HI• 10,000 –moderate HI causing unconsciousness for 0-

6hrs. Some have physical & psychological problems after 5yrs

• 11,600 –severe HI, unconscious 6+hrs. Of these only approx 15% return to work within 5yrs

• Males 2-3 x more likely to suffer HI• Age group 15-29 mainly (x5 more males within this

group)(www.headway.org.uk)

Classification• Open

Focal – Direct blow to the head or from a fall (Assault 10%, Domestic incidents 20-30%, Sport 10-15%, Cycling - °helmet 20%)Diffuse – Acceleration/Deceleration forces result in

shearing and contusion injury to the brain (RTA 40-50%)

• Closed Penetrating – Low velocity (stab wound) or High velocity (Gun shot/Nail gun). Resultant local damage to the brain and along the tract

Contra-coup injury – RTA/Fall

Example of internal injury

Closed Head Injury -AlternativesClosed head injury can also relate to a pathological damage without trauma:

• CVA• Sub-arachnoid haemorrhage• Aneurysm• Cerebral oedema• Altered conscious level due

to electrolyte imbalance e.g. encephalopathy

Examples

Open Head Injury – Skull Penetration

Actual brain injury

• Bruising - small blood vessels ruptured, haematoma can form

• Tearing - may not be observed on CT/MRI

• Swelling – as a result of the normal response to injury i.e. exudate, increased blood flow, heat

Implications of head injury

• If trauma is the cause of injury then other major structures are likely to be involved e.g. chest wall injury and lung damage, multiple fractures, abdominal & pelvic injuries

• Major blood loss• Loss of consciousness resulting in airway

compromise

↓CRITICALLY ILL PATIENT

Cerebral Haemodynamics

Cerebral Blood Flow – depends upon:• Arterial BP (Mean 50-150mmHg)• CO2 – most potent effect (small PaCO2 = ICP.

Each KPaCO2 causes 20% ICP)• Oxygen – brain uses 1/6 of cardiac output. If

PaO2,8KPA then vasodilation occurs and increases CBF hence increased ICP

[CPP – Mean arterial BP – ICP]

Factors increasing ICP

• Positioning – tip & turn, head movements• Anxiety, pain• Cough• Suctioning• Hypoxaemia/hypercapnia• Physiotherapy• Pyrexia• Worsening oedema, bleeding

Medical Management

• Aims:

1. Treat 1° brain injury

(stop bleeding, remove clots, prevent/remove increased pressure –craniotomy,burr holes,bone flap removal? Control ICP, maintain adequate CBF)

2. To prevent further 2° Brain damage

(ICP, Sputum retention,Hypoxia,Hypovolaemia)

GM AIM/ALERTPrinciples of Assessment

ABCDE Assessment

• A (Airway) - Maintain Airway

• B (Breathing) - Ventilate & Sedate

(GCS<8)

• C (Circulation) - Monitor CVS

• D (Disability) - Neurological Assessment

• E (Extremity) - Control Fitting

Further Medical Management

• Maintain CPP Metabolic Demands

• Promote Cerebral draining

• CSF drainage

• Dehydrate

• Decompress

• Drugs

Monitoring

• ICP bolt:– fine, hollow screw placed through a

twist drill hole in the skull

– ‘floats’ in sub-arachnoid space

– line attached from screw to transducer

– pressure reading appears on monitor

Management of ICP

• Maintain blood pressure with adequate volume• Positioning – head in midline/elevated 30°• Sedate and paralyse as necessary• Hyperventilate to reduce CO2

• Maintain adequate oxygenation• Drug therapy to stabilise blood pressure and

reduce oedema

Surgery may still be required!

ICU Environment

                

                                                                              

Acute Stage:• Pts frequently sedated, paralysed and hyperventilated for

24-48 hrs to pt prevent hypoxia and 2y brain damage.

• RULE = minimal handling

• AX: To identify any respiratory problems which may affect gaseous exchange (Aspiration at time of injury are common)

• NO routine Rx should be administered & suction to minimum as it raises ICP!!

Neurological / Head Injured Patients

Chest Complications?

Why do head injury patients develop chest problems?

Neurological / Head Injured Patients

• Rx when indicated, request additional sedation to minimise its detrimental effects (Klein et al 1988).

• Harmonise position change with nursing procedures to minimise handling.

• Keep head in midline and raised 30 degrees from horizontal & minimise hip flexion to maintain brain’s venous drainage.

• Manual techniques can potentially raise ICP• MHI = controversial but if used it is essential to

hyperinflate pt to maintain low CO2 level

Assessment

Suitable for Physiotherapy Not suitable for Physiotherapy Unstable vital signs (ICP>20: CPP<50mmHg)

PulmonaryComplications

No Pulmonary Complications - (Clear CXR, Normal Ausc and °retention secretions)

Treatment Poorly tolerated –STOP: Stabilise and reassess later

Treatment Well Tolerated – Repeat in situ or log roll (head midline) and continue Rx

Leave and

Re-Ax later

Low RiskHigh Risk (Labile ICP/BP

CPP>50, ICP 15-30mmHg)

Treatment A

FiO2, Modify postural drainage (head midline), Saline/Mucolytic

instillation,MHI with Vibs, Suction

Treatment B

Bolus thiopentone, FiO2, Rx in situ, Saline/Mucolytic instillation, MHI

occasional large TV breaths with vibs, Suction (preceded & followed by

hyperventilation)

Prasad & Tasker (1990)

Physiotherapy Techniques

• Respiratory – exp vibs, shaking, MHI, suction, positioning

• Extremities – Positioning to midline alignment, Passive mvts & stretches, Splinting as appropriate, Active mvt ax,

Neurological / Head Injured Patients

Sub acute stage:• As sedatives are eliminated from the pts body, the full extent of

neurological damage becomes apparent.• Weaning from MV can be difficult as the pts central control systems

may be damaged causing either hypo or hyperventilation.• Cough &/or gag reflexes may be absent• Apart from irreversible brain damage – chest infection is the largest

killer!, therefore constant attention of resp system is required.• Sitting out of bed as early as possible is advocated (Adams et al 1998)

Refer for appropriate specialist rehabilitation ASAP (CVS & Neurological stability)

Glossary • ICP – Intra Cranial Pressure• CPP – Cerebral Perfusion Pressure• CBF – Cerebral Blood Flow• BP – Blood Pressure• Mean Arterial BP = Diastolic + (Systolic-Diastolic)

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• [CPP – Mean arterial BP – ICP]• GM AIM – Greater Manchester Acute Illness

Management (Multi-professional Course written on behalf of Greater Manchester Workforce Development Confederation)

Bibliography• Adams, A., et al (1998). ‘Chapter 6 The Intensive

Care Unit’, In: M. Smith, & V. Ball, (1998), Cardiovascular / Respiratory Physiotherapy. London: Mosby, pp 73 – 117.

• Enright, S., (1992). ‘Cardiorespiratory effects of chest physiotherapy’, Intensive Care Britain, 1992, p118-123.

• Fewings, J. (1999) ‘Management of the Acute Head Injury’, Royal Hallamshire Hospital, Sheffield, (Unpublished presentation).

• GM AIM (2003) ‘Greater Manchester Acute Illness Management’, Course Booklet. Greater Manchester Critical Care Skills Institute NHS.

Bibliography

• Klein et al (1988). ‘Attenuation of the Haemodynamics responses to chest physical therapy’, Chest, 1988, Vol 93, pp38-42.

• Pappart et al (1994). ‘Influence of positioning on ventilation-perfusion relationships in severe adult respiratory distress syndrome’, Chest, 1994, Vol 106, pp 1511-1516.

• Prasad, A and Tasker,R. (1990) ‘Guidelines for the Physiotherapy Management of the Critically Ill Children with Acutely Raised Intracranial Pressure’, Physiotherapy 76 (4), p248-250.

Bibliography

• http://images.google.co.uk/imgres?imgurl=http://littlepieces.tazzy.nl/weblog/spijkers.jpg&imgrefurl=http://littlepieces.tazzy.nl/&h=267&w=210&sz=13&tbnid=KUAj-Y4UsD4J:&tbnh=107&tbnw=84&start=40&prev=/images%3Fq%3Dgun%2Bshot%2Bto%2Bhead%26start%

• http://www.headway.org.uk/default.asp?step=4&pid=11

• http://www.headway.org.uk/default.asp?step=4&pid=38