Approach to

Contents Clinical Evaluation History Examination Lab Evaluation Management

Basics Wakefulness depends on the integrity of both cerebral hemi- spheres and the ascending reticular activating formation of the brain stem.

Cont.. The management of an unconscious patient is never an easy task in clinical practice The duty of physician is Arrive at diagnosis Predict the eventual outcome

History

Onset of coma (abrupt, gradual) ii) Recent complaints ( headache, depression, focal weakness, vertigo ) iii) Recent injury iv) Previous medical illness ( diabetes,uraemia, heart disease ) v) Access to drugs ( sedatives,psychotropic drugs )

Examination

General physical Examination i) Vital signs ii) Evidence of trauma iii) Evidence of acute or chronic system illness iv) Evidence of drug ingestion ( needle marks alcohol breath ) v) Nuchal rigidity (examine with care)

Neurological Examination

State of consciousness Obtundation; responds-to verbal stimuli although slow and inappropriate. Stupor; the subject can be aroused only by vigorous and repeated noxious stimuli. Coma; unarousable and unresponsive. Stupor; the subject can be roused only by vigorous and repeated noxious stimuli.

Respiratory pattern a ) Hyperventilation - midbrain and upper pons lesion metabolic diseases e.g. hepatic coma, diabetes and generalised raised intracranial pressure in its early stages. ( b ) Hypoventilation - medullary, upper cervical spinal lesion Drug overdose and later stages of cerebral herniation. ( e ) Cheyne-Stoke respiration – usually diencephalic lesion central transtentorial herniation and obstructive hydrocephalus. ( d ) Ataxic respiration (completely irregular breathing) brain-stem dysfunction of a diffuse nature

Pupillary size and reaction Medium to dilated symmetrical pupils fixed to light structural disease of the brain stem. Small symmetrical pupils reactive to light metabolic diseases and drug overdose. Unequal pupil fixed to light intracranial mass lesion producing 3rd nerve palsy e.g in unilateral uncal herniation.

Eye movements Vestibulo-ocular reflexes – douching of one ear with cold water produces ipsi-lateral deviation of both eyes with a contralateral quick phase nystagmus lasting for 1—2 minutes. Use of hot water produces the opposite effect i.e. contralateral deviation with ipsilateral quick phase nystagmus. Bilateral douching with cold water gives rise to downward deviation with upward nystagmus and with hot water the opposite response. Absence or abnormal response indicates brain-stem dysfunction. Oculo-cephalic reflexes (Doll's eye movement ) - Normal response consist of deviation of both eyes to the opposite direction of head rotation. Again absence or abnormal response indicates brain-stem dysfunction.

Motor Responses This is elicited by applying peripheral noxious stimuli e.g. pinching of limbs rubbing the sternum to elicit pain. ( a ) Appropriate response – brushing away the source of stimulus. { b ) Inappropriate response - decerebrate or decorticate rigidity. Motor response is also of localising value. Paralysed limb will show no response and presence of hemiplegia can therefore be evident. Decerebrate rigidity indicates brain-stem damage and if bilateral is usually associated with a very poor prognosis. Complete flaccidity with no response to noxious stimuli is often indicative of severe central nervous system depression due to drug overdose.

Laboratory Evaluation

Supratentorial lesions Skull radiograph Computerised tomographic scan CTscan) Carotid angiography EEG ( electroencephalogram )

Infratentorial lesions Skull radiograph CT scan Vertebral angiography EEG Ventriculography

Diffuse neuronal lesions Examination of CSF ( cerebro spinal fluid ) Serum glucose, calcium, Na, K, magnesium Blood gases and PH Liver and renal functions Drug levels

Management

Initial Management Airway Breathing Circulation Deformity Exposure

Definitive Management In general, management of the comatose patient depends on the cause. However, while the patient is undergoing evaluation, it is essential to : pressure area care care of the mouth, eyes and skin physiotherapy to protect muscles and joints risks of deep vein thrombosis risks of stress ulceration of the stomach nutrition and fluid balance urinary catheterization monitoring of the CVS infection control maintenance of adequate oxygenation, with the assistance of artificial ventilation

You are in emergency department when an unconscious patient land in emergency with B.P 90/50 pulse 92/min and attendants tell u that the patient suddenly fell unconscious, how will you approach ?

APPROACH ABC Immediate management Examination History Investigations

ABC

Immediate management Maintain i.v line, oxygen inhalation Blood sample for RBS Control seizures Consider i.v glucose, thiamine, naloxone, flumazenil

Examination

Vitals CONTD. 1.Pulse tachycardia Hypovolemia/haemorrhage hyperthermia Intoxication bradycardia Raised intracranial pressure Heart blocks

CONTD. 2.Temperature increased Sepsis Meningitis ,encephalitis Malaria ,Pontine haemorrhage Decreased Hypoglycemia Hypothermia (less than 31 C) Myxedema Alcohol, barbiturate ,sedative or phenothiazine intoxication.

CONTD. 3.Blood pressure increased Hypertensive encephalopathy Cerebral haemorrhage Raised intracranial pressure Decreased Hypovolemia /hgr Myocardial infarction Intoxication/poisoning Profound hypothyroidism, Addisonian crisis

Increased(tachypnae) CONTD. 4.Respiratory rate Increased(tachypnae) Pneumonia Acidosis (DKA, renal failure) Pulmonary embolism Respiratory failure Decreased Intoxication/poisoning

Skin petechial rash CONTD. Meningococcal meningitis Endocarditis Sepsis,thrombotic thrombocytopenic purpura Rickettsial infection RMS (rocky mountain spotted fever)

Multiple injection marks CONTD. Multiple injection marks Drug addiction Acute endocarditis Hepatitis B /C with encephalopathy HIV

Neurological assessment; CONTD. Neurological assessment; General posture Level of conciousness

Posture; CONTD. Lack of movements on one side Intermittent twitching Multifocal myoclonus DECORTICATION DECEREBRATION

Level of conciousness CONTD. Glasgow coma scale (GCS) Best motor response Best verbal response Eye opening GCS score 3 –severe injury less than or equal to 8 – moderate injury 9 to 12 – minor injury

CONTD. An abbreviated coma scale is used in the assessment of critically ill patient (primary servey) AVPU A –alert V – respond to voice stimulus P – respond to pain U - unresponsive

Brainstem reflexes Pupillary responses to light Spontaneous and elicited eye movements Corneal responses Respiratory movements

CONTD. Ocular movements Conjugate deviation of eyes to a side – ipsilateral hemisphere frontal leison or contralateral pontine leison. Rarely eyes may turn paradoxically away from the side of deep hemisphere leison (WRONG-WAY EYES) Downward conjugate deviation of eyes – mesencephalic leison.

CONTD. Eyes turn down and inward in – thalamic hgr and upper midbrain leison. Ocular bobbing – is diagnostic of pontine hgr. Ocular dipping - indicates diffuse cortical anoxic damage. Dysconjugate ocular deviation – brainstem leison.

CONTD. Oculocephalic reflex (Doll’s eyes response) – brisk in cortical depression ,lost in brainstem leison. Oculovestibulo responses –two components 1.Conjugate ocular movement – loss in brainstem damage. 2.Nystagmus – loss in damage to cerebral hemisphere

CONTD. Pupillary changes; Sr no pupils causes 1 B/L Pin-point pupils ( less than 1mm)but responsive Opiates poisoning ,extensive pontine hgr. 2 B/L small pupils but responsive B/L diencephalon involvement or destructive pontine leison 3 B/L slightly small pupils(1 to 2.5 mm) but responsive Metabolic encephalopathies ,deep B/L hemisphere leison or thalamic hgr. 4 B/L dilated and fixed Severe midbrain damage, Overdose of atropine,scopolamine, glutethemide.

CONTD. Sr. no. Pupil cause 6 U/L small pupil Horner syndrome 5 Ipsilateral dilated pupil with no direct or consensual reflexes Compression of 3rd cranial nerve e.g, uncal herniation 7 U/L small and irregular pupil unresponsive Leison in pretectal area of midbrain

CONTD. Respiratory movements Has less localizing value then other brainstem reflexes. Cheyen-stokes respiration(classic cyclic form ending with a brief apneic period – B/L hemisphere damage or metabolic depression. Rapid ,deep breathing (Kussmaul) –in metabolic acidosis and in pontomesencephalic leison.

Neck rigidity; Meningitis Subarachnoid haemorrhage

Fundoscopy Raised intracranial pressure Hypertensive changes Subarachnoid haemorrhage Diabetic retinopathy

History Onset of the symptoms Antecedent symptoms Use of medications Chronic liver ,kidney ,lung or heart disease

CAUSES OF UNCONCIOUSNESS

Causes of unconciousness Metabolic Drugs, poisoning e.g CO ,alcohol Hypoglcemia, hyperglycemia (keto acidoti or HONK) Hypoxia, carbondiaoxide narcosis (COPD) Septicemia Hypothermia Myxedema ,addisonian crisis Hepatic / uremic encephalopathy

CONTD. Neurological Trauma Infections – meningitis, encephalitis, malaria, typhoid, rabies, trypanosomiasis. Tumours – cerebral / meningeal tumors Vascular – subdural / subarachnoid hgr, stroke, hypertensive encephalopathy Epilepsy – nonconvulsive status / postictal state

Immediate investigations RBS Blood CP and ESR LFTs Urea and Creatnine Blood and urine cultures

Other investigations CRP ABGs Toxic screen , drug levels Lumbar puncture and CXR CT scan

Stabilize cervical spine Summary ABC of life support Oxygen and I.V access Stabilize cervical spine

Consider I.V glucose, thiamine, naloxone, flumazenil CONTD. Blood glucose Control seizures Consider I.V glucose, thiamine, naloxone, flumazenil

CONTD. Brief examination and obtain history Investigate Reassess the situation and plan further

Take home message Early management Prompt diagnosis

MCQ Pupillary changes in opiate poisoning 1.B/L pinpoint 2.U/L pin point 3.B/L dilated

Answer 1. B/L pin point

MCQ Myxoedema coma seen in 1.Euthyroid state 2.Hyperthyroid state 3. hypothyroid state

Answer 3. hypothyroid state

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