COMACOMA

Introduction-etiology-Introduction-etiology-pathophysiologypathophysiology

Dr. David Dr. David WilliamsWilliams

Asst. Professor Asst. Professor of of PaediatricsPaediatrics

DefinitionDefinition Def: It is a state in which the patient Def: It is a state in which the patient

makes no meaningful response to makes no meaningful response to external stimulus or innerneed.external stimulus or innerneed.

States of decreased consiouness.lethargy-States of decreased consiouness.lethargy-difficult to maintain aroused difficult to maintain aroused state.obtundation-response to stimulation state.obtundation-response to stimulation other than pain.stupor-response only to other than pain.stupor-response only to pain.coma-unresponsive to pain.pain.coma-unresponsive to pain.

Coma is a disorder of arousability.Coma is a disorder of arousability.

Coma scalesComa scales Glasgow coma scaleGlasgow coma scale Modified coma scaleModified coma scale Adelaid coma scaleAdelaid coma scale Blantyre coma scaleBlantyre coma scale Infant face scale Infant face scale AVPU scoreAVPU score

Coma scalesComa scales Every Scale consists of 3 main Every Scale consists of 3 main

componentscomponents Eye openingEye opening Best motor response Best motor response Best verbal response Best verbal response

Different coma scalesDifferent coma scalesEye openingEye opening GCSGCS Modified Modified

GCSGCSAdelaAdelaid id coma coma scalescale

SpontaneousSpontaneous 44 44 44

Response to Response to speechspeech

33 33 33

Response to painResponse to pain 22 22 22

NoneNone 11 11 11

Different coma scalesDifferent coma scalesBest motor Best motor responseresponse

GCSGCS ModifieModified GCSd GCS

AdelaAdelaid CSid CS

Obeys commandsObeys commands 66 66 66

Localises painLocalises pain 55 55 55

Withdrawal of limbWithdrawal of limb 44 44 44

Flexion to painFlexion to pain 33 33 33

Extension to painExtension to pain 22 22 22

NilNil 11 11 11

Best verbal responseBest verbal responseGCSGCS Modified Modified

GCSGCSAdelaid coma Adelaid coma scalescale

scorscoree

OrientedOriented Coos, Coos, babblesbabbles

orientedoriented 55

Confused Confused Irritable Irritable crycry

Words Words 44

InappropriateInappropriatewordswords

Cries to Cries to painpain

Vocal soundsVocal sounds 33

IncomprehenIncomprehensiblesiblewordswords

Moans to Moans to painpain

CriesCries 22

NilNil NilNil NilNil 11

Infant face scaleInfant face scale It relies on objective behavioral It relies on objective behavioral

observation. Uses cortical as well as observation. Uses cortical as well as brain stem function. It parallels brain stem function. It parallels GCS in score & based on infant GCS in score & based on infant appropriate behavior. It can be appropriate behavior. It can be applied even in intubated patients.applied even in intubated patients.

Eye opening ,motor & verbal Eye opening ,motor & verbal responses are tested. Defined either responses are tested. Defined either almost perfect or sustained.almost perfect or sustained.

Blantyre coma scaleBlantyre coma scaleResponsResponsee

FindingsFindings scoscorere

BestmotBestmotor or responsresponsee

localizes painful stimulus (pressure localizes painful stimulus (pressure with blunt end of pencil on sternum or with blunt end of pencil on sternum or supraorbital ridge)supraorbital ridge)

22

withdraws limb from painful stimulus withdraws limb from painful stimulus (pressure with horizontal pencil on nail (pressure with horizontal pencil on nail bed of finger or toe)bed of finger or toe)

11

no response or inappropriate responseno response or inappropriate response 00Best Best verbal verbal responsresponsee

cries inappropriately with painful cries inappropriately with painful stimulus, or, if verbal, speaksstimulus, or, if verbal, speaks

22

moan or abnormal cry with painful moan or abnormal cry with painful stimulusstimulus

11

no vocal response to painful stimulusno vocal response to painful stimulus 00Eye Eye mov.mov.

watches or follows (e.g., mother's face)watches or follows (e.g., mother's face) 11

fails to watch or followfails to watch or follow 00

Interpretation of Blantyre Coma Interpretation of Blantyre Coma ScaleScale Maximum score – 5 ( good)Maximum score – 5 ( good) Minimum score – 0 (poor)Minimum score – 0 (poor) Abnormal score <=4Abnormal score <=4

Other scoresOther scores AVPU score :AVPU score :

A – AlertA – Alert V – Response to voiceV – Response to voice P – Response to painP – Response to pain U – Unresponsive U – Unresponsive

Etiology of coma in Etiology of coma in childrenchildren

Infections –Infections – Meningitis Meningitis EncephalitisEncephalitis Cerebral malariaCerebral malaria Intra cerebral absessIntra cerebral absess Sub dural empyemaSub dural empyema Epi dural empyemaEpi dural empyema Gram –ve septicemiaGram –ve septicemia Sepic shock, Typhoid encephalopathy, Sepic shock, Typhoid encephalopathy,

Shigella encephalpathy, Dengue shock Shigella encephalpathy, Dengue shock syndrome.syndrome.

Rare causes -burn enchalopathy,lyme Rare causes -burn enchalopathy,lyme disease,disease,

Etiology Etiology Hypoxia-ischemia*; Hypoxia-ischemia*;

hypoxia – hypoxia –normal cerebral normal cerebral blood flow, hypo blood flow, hypo ventilation, ventilation, methemoglobinemimethemoglobinemia, ischemia –a, ischemia –decreased cerebral decreased cerebral blood flow.blood flow.

Drug induced or Drug induced or over dosage. over dosage. Barbiturate Barbiturate *,transquilisers*,op*,transquilisers*,opiates ,anti iates ,anti cholinergics.cholinergics.

Etiology Etiology Supra tentorial Supra tentorial

lesions- cerebral lesions- cerebral haemorrhage,cerebrhaemorrhage,cerebral infarction,sub al infarction,sub dural dural haematoma,epidural haematoma,epidural haematoma,cerebral haematoma,cerebral absess,cerebral absess,cerebral edema,pitutary edema,pitutary apoplexy,tumors ,coapoplexy,tumors ,contusion –laceration,ntusion –laceration,

Sub tentorial Sub tentorial lesions- lesions- cerebellar cerebellar haemorrhage,brain haemorrhage,brain stem stem infarction,tumors,poinfarction,tumors,pontine ntine haemorrhage,cerebhaemorrhage,cerebellar ellar absess,tentorial absess,tentorial herniation.herniation.

Etiology Etiology Epilepsy: Epilepsy:

post ictal post ictal state, status state, status epilepticus.epilepticus.

Deficiency states-Deficiency states-thiamine , thiamine , niacin ,pyridoxine,niacin ,pyridoxine,vit-b12.vit-b12.

Etiology Etiology Cardiac causes- Cardiac causes-

decreased decreased cardiac out put due cardiac out put due to arrhythmias or to arrhythmias or valvular disease. valvular disease. Generalised fall Generalised fall of blood pressure-of blood pressure-hypovolemia, vaso hypovolemia, vaso vagal syncope, vagal syncope, carotid sinus carotid sinus massage.massage.

Vascular causes-Vascular causes-hypertensive hypertensive encephalopathy, encephalopathy, polycythemia, polycythemia, emboli,thrombosis emboli,thrombosis ,vasculitis,a-v ,vasculitis,a-v malformations,haemalformations,haemorrhagic morrhagic diseases.diseases.

Etiology Etiology Metabolic & systemic Metabolic & systemic

disorders. disorders. Hypoglycemia, diabetic Hypoglycemia, diabetic ketoacidosis, hepatic ketoacidosis, hepatic encephalopathy, uraemic encephalopathy, uraemic encephalopathy,hyper encephalopathy,hyper tensive encephalopathy, tensive encephalopathy, reyes reyes encephalopathy,ammoniencephalopathy,ammonia encephalopathy, urea a encephalopathy, urea cycle defects, branched cycle defects, branched chain aa or organic chain aa or organic acidemias.acidemias.

Thyroid Thyroid disorders ,adrenal disorders ,adrenal insuficiecy,medium insuficiecy,medium chain acyl co a chain acyl co a dehydrogenase dehydrogenase def ,theral def ,theral injury,cardio injury,cardio respiratory failure.respiratory failure.

Pathophysiology of comaPathophysiology of coma Loss of consciousness – Loss of consciousness –

Decreased blood flow to brain, Decreased blood flow to brain, decreased oxygen supply to brain, toxin decreased oxygen supply to brain, toxin induced damage.induced damage.

Acute drop of cerebral blood flow Acute drop of cerebral blood flow from 55ml/min/100g to from 55ml/min/100g to 25ml/min/100g25ml/min/100g Slowing of EEG & syncopeSlowing of EEG & syncope

Pathophysiology of comaPathophysiology of coma A drop in CBF to <12 -15 A drop in CBF to <12 -15

ml/min/100gml/min/100g Electrocerebral silenceElectrocerebral silence ComaComa Cessation of metabolic & synaptic Cessation of metabolic & synaptic

functionsfunctions O2 consumption of 2 mg/min/100g O2 consumption of 2 mg/min/100g

(app half of normal) (app half of normal) Incompatible with alert stateIncompatible with alert state

Disease process Disease process Toxin/effects Toxin/effects

DKADKA

UremiaUremia Hepatic comaHepatic coma Lactic acidosisLactic acidosis Pulmonary Pulmonary

insufficiencyinsufficiency HyponatremiaHyponatremia

Acetone bodies Acetone bodies ( acetone & B-OH ( acetone & B-OH butyric acid)butyric acid)

Dialyzable toxinsDialyzable toxins NH3 > 5-6 times NH3 > 5-6 times Arterial PH <7Arterial PH <7 HypercapneaHypercapnea Neuronal swelling, Neuronal swelling,

loss of KCl from loss of KCl from cellscells

Disease process Disease process Toxin/effectsToxin/effects

Gen anestheticsGen anesthetics AlcoholAlcohol OpiatesOpiates BarbituratesBarbiturates Phenytoin Phenytoin AntidepressantsAntidepressants BenzodiazepinesBenzodiazepines Methyl alcoholMethyl alcohol Ethylene glycolEthylene glycol

Direct effect on Direct effect on neuronal neuronal membranes in membranes in cerebrum & RAS cerebrum & RAS

Metabolic acidosisMetabolic acidosis

Disease process Disease process Toxin/effectsToxin/effects

Seizures Seizures

Concussion Concussion

Local anestheticsLocal anesthetics

Spread of seizures Spread of seizures discharge to deep discharge to deep central structurescentral structures

Rotation of cerebral Rotation of cerebral hemispheres around hemispheres around the axis of upper the axis of upper brainstembrainstem

Interaction with Interaction with ligand gated ion ligand gated ion channels & channels & alterations in alterations in neurotransmittorsneurotransmittors

Pathoanatomy of comaPathoanatomy of coma1.1. Grossly discernible mass lesion Grossly discernible mass lesion

causing lateral displacement of deep causing lateral displacement of deep central structures ( herniation)central structures ( herniation)

2.2. Destructive lesion in central Destructive lesion in central structures like thalamus or midbrainstructures like thalamus or midbrain

3.3. Widespread damage to cortex & Widespread damage to cortex & cerebral white mattercerebral white matter

THANQTHANQ