General Approach And

Differential Diagnosis of Coma

OBJECTIVES

• Objective: Able to stabilize, evaluate, and

treat the comatose patient in the emergent

setting.

• To understand this involves an organized,

sequential, prioritized approach.

The Comatose Patient

Objectives

• Airway

• Breathing

• Circulation

• Treatment of rapidly progressive, dangerous

metabolic causes of coma (hypoglycemia)

• Evaluation as to whether there is significant

increased ICP or mass lesions.

• Treatment of ICP to temporize until surgical

intervention is possible.

Why Coma management

• Common medical emergency 3-5%

• Large proportion of comatose patient

recover

• Untreated coma may lead to further brain

damage

Is it Coma ?

Coma is prolonged Unconsciousness Or

Unarousible Unresponsiveness.

Quantify using the Glasgow coma

scale.

Causes/Differential Diagnosis of

Coma

• Traumatic - head injury

• Vascular - Cerebral thrombosis

Cerebral Haemorrhage (ICH/SAH)

Hypertensive encephalopathy

• Meningitis,encephalitis,brain abscess,cerebral malaria

• Brain tumor & other SOL

• Epilepsy & postictal states

• Psychiatric problems (Hysteria,depression,catatonia)

• Organ failure - hepatic coma,respiratory coma,uraemic

coma

• Metabolic

Hyperglycemia , hypoglycemia

Hypernatraemia , hyponatracemia

Hyperthermia , hypothermia

Hypercalcaemia , Water intoxication (SIADH)

Diabetic coma

Myxodemic coma

• Endogenous

Intoxication / drugs - sedative,morphine,pethidine

Alcohol intoxication : alcohol withdrawl $

Consciousness

• Perception

• Reaction

• Wakefulness

Level of

consciousness

Spontaneous 4

To Speech 3

To Pain 2

Absent 1

Converses/Oriented 5

Converses/Desoriented 4

Inapropriate 3

Incomprehensible 2

Absent 1

Obeys 6

Localizes Pain 5

Withdraws(flexion) 4

Decorticate(flexion)

Rigidity 3

Decerebrate(extension)

Rigidity 2

Absent 1

Eyes Open

Verbal

Motor

The sum obtained in this scale is used to the assess

Coma and Impaired consciousness

Mild is 13 through 15 points

Moderate is 9 to 12 points

Severe 3 through 8 points

Patients with score less than 8 are in Coma

GCS

Coma - Aetiology

Metabolic:-

– Ischemic hypoxic

– Hypoglycaemic

– Organ failure

– Electrolyte disturbance

– Toxic

Structural:-

– Supratentorial bilateral

– Unilateral large lesion

with transtentorial

herniation

– Infratentorial

Metabolic encephalopathy

• Confusional state -> coma , fluctuation

• No focal neurological sign

• No neck stiffness

• Normal brainstem reflexes

• Coarse tremor

• Multifocal myoclonus

• Asterixis

• Generalized/periodic myoclonus

History

• Circumstances and temporal profile

• Of the onset of coma

• Details of preceding neurological symptoms

headache, weakness and seizure

• Any head injury

• Use of drug (e.g. Steroid) and alcohol

• Previous medical illness liver, kidney

• Previous psychiatric illness

Examination

• General physical examination

• Evidence of external injury

• Colour of skin and mucosa

• Odour of breath

• Evidence of systemic illness

• Heart and lung

Neurological examination

• Fundoscopy

• Pupil size and response to light

• Ocular movements

• Posture and limb movement

• Reflexes

Cushing Triad

Kocher-Cushing response - rise in BP-

>bradycardia due to rise in ICP ->

compression of floor of the 4th ventricle

Stimulation to respiratory center- increase

respiratory rate

fall in BP and tachycardia usually terminal

event due to medullary failure

Pupil

• Diencephalic (metabolic) Small reactive

• Midbrain tectal Midsize,fixed

• Midbrain nuclear Irregular pear

shaped

• 3rd nerve Fixed widely dilated

• Pontine haemorrhage Pinpoint reactive

Opiate Pinpoint

• Organophosphorus Small

• Atropine Wide dilated

Motor Exam Key Points:

• Assess tone, presence of asterixis

• Response to painful stimuli

– none

– abnormal flexor

– abnormal extensor

– normal localization/withdrawal

• Symmetric responses seen with metabolic or structural causes

• Asymmetric responses seen with structural causes

Posture

• Cerebral hemisphere

– Decorticate posture

• Diencephalon supratentorial

– Diagonal posture

• Upper brain stem

– Decerebrate posture

• Pontine

– Abnormal ext arm

– Weak flexion leg

• Medullary

– Flaccidity

Investigation

• Complete blood count, MP, B.sugar

• Blood urea, s. creatinine,

s.electrolyte

• Blood gases, ALT, AST

• CSF examination

• CT scan/ MRI

• X-ray chest, ECG

Management

• Check vital signs - BP,HR,RR

Patent airway

Adequate breathing

Adequate circulation

• Correct the reversible cause

Rapid history taking & rapid and through P.E

50% glucose

Nalosone, Nalophine (Narcotic overdose)

Vit B1 for Wernicke’s encephalopathy

Flumazenil if coma due to diazepam overdose

• GCS assessment

Treatment

1. Turn the patient frequently to prevent aspiration,sore,hypostasis

– Skin care

– Bladder care

– Bowel care

Continue treatment

2. If the General condition stablilized, do CT head scan to detect

organic lesion

– Infract can’t be seen immediately,can see at least 6-8 hr

– Haemorrhage can be seen immediately-do CT scan

immediately

– Tumour-can see as SOL

3. CT head - Normal -do LP

– If infection present - treat

4. CT & LP - normal - treat metabolic (if consider metabolic)

– If deteriorate ,consider expansion of disease, new lesion and metabolic

5. Increased ICP - osmotic diuresis

– Mannitol - 20% in 200cc N/S within 20min.

6. Evaculation of Haemorrhage - refer to neurosurgery

7. Infract - symptomatic treatment

• Prognosis

– Can be determined by GCS & Head injury

– If there is no improvement within 48 hr, prognosis is bad.