The document provides guidance on approaching and managing a comatose patient. It outlines that the primary objectives are to stabilize, evaluate, and treat the patient by taking an organized sequential approach that prioritizes the airway, breathing, circulation, treating metabolic causes of coma like hypoglycemia, and evaluating for increased intracranial pressure or mass lesions. Secondary objectives include understanding the signs and symptoms of different causes of coma and developing a differential diagnosis. The document then provides detailed information on assessing different aspects of the comatose patient including their level of consciousness, neurological exam findings, breathing patterns, eye movements, motor response, and appropriate investigations.

1. Approach to Coma

2. OBJECTIVESPrimary Objective: Able to stabilize, evaluate, and treat the comatose patient in the emergent setting. To understand this involves an organized, sequential, prioritized approach.

3. The Comatose PatientPrimary ObjectivesAirwayBreathingCirculationTreatment 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.

4. The Comatose PatientSecondary ObjectivesUnderstand and recognize:ComaSigns of supratentorial mass lesionsSigns of subtentorial mass lesionsHerniation syndromesAble to develop the differential diagnosis of metabolic coma.

5. Why Coma managementCommon medical emergency 3-5%Large proportion of comatose patient recoverUntreated coma may lead to further brain damage

6. Is it Coma ?Coma is prolonged Unconsciousness

7. ConsciousnessPerception -Awareness of self and environment ( Sensory System)Reaction – Meaningful responsiveness (Motor system)Wakefulness – (Sleep wave cycle)

8. Component of consciousnessArousal - appearance of wakefulnessContent - the sum of cognitive and affective function

9. GCSEyes OpenLevel of consciousnessVerbalMotorThe sum obtained in this scale is used to the assess Coma and Impaired consciousness Mild is 13 through 15 pointsModerate is 9 to 12 pointsSevere 3 through 8 pointsPatients with score less than 8 are in Coma

10. Coma mimicsPsychogenic unresponsivenessLocked in syndromeAkineticmutismCatatoniaPersistent vegetative state

11. Psychogenic comaHolds eye tight, resist openingFixed stare, quick blinkNormal pupilNormal oculocephalicNormal oculovestibularNormal posture, breathing, bp,pulse

12. Coma PathophysiologyComa implies dysfunction of:Ascending Reticular Activating System orBoth hemi-corticesAnatomically, this meanscentral brainstem structures (bilaterally) from caudal medulla to rostral midbrainboth hemispheres

13. Coma - AetiologyMetabolic:-Ischemic hypoxicHypoglycaemicOrgan failureElectrolyte disturbanceToxicStructural:-Supratentorial bilateralUnilateral large lesion with transtentorial herniationInfratentorial

14. Supratentorial LesionsEpidural or Subdural Hematoma Intraparenchymal haemorrhageLarge Ischemic InfarctionTumourTraumaAbscess

15. Supratentorial Mass LesionsDifferential CharacteristicsInitiating signs usually of focal cerebral dysfunctionSigns of dysfunction progress rostral to caudalNeurologic signs at any given time point to one anatomic area - diencephalon, midbrain, brainstemMotor signs are often asymmetricalPlum and Posner, 1982

16. Rostral Caudal Progression

17. Rostral Caudal Progression

18. Rostral Caudal Progression

19. Infratentorial LesionsCause coma by affecting reticular activating system in ponsBrainstem nuclei and tracts usually involved with resultant focal brainstem findings

20. Infratentorial LesionsBasilar artery thrombosisPontine or Cerebellar HematomaIschemic Cerebellar InfarctionTumourAbscess

21. Infratentorial Mass LesionsDifferential CharacteristicsHistory of preceding brainstem dysfunction or sudden onset of comaLocalizing brainstem signs precede or accompany onset of coma and always include oculovestibular abnormalityCranial nerve palsies usually present“Bizarre” respiratory patterns common, usually present at onset of comaPlum and Posner, 1982

22. Metabolic encephalopathyConfusional state -> coma , fluctuationNo focal neurological signNo neck stiffnessNormal brainstem reflexesCoarse tremor 8-10hzMultifocal myoclonusAsterixisGeneralized/periodic myoclonus

23. HistoryCircumstances and temporal profileOf the onset of comaDetails of preceding neurologicalSymptoms headache, weakness seizureAny fallUse of drug and alcoholPrevious medical illness liver,kidneyPrevious psychiatric illness

24. Other symptoms of comaYawningPoor localizing valuePosterior fossa expanding lesionMedial temporal, third ventricular HiccupMedullary lesion in the region of Third ventricleVomitingLateral reticular formation of the medullaProjectile ( usually nausea)Medulloblastoma ependymomaRaised icp -> compression of medullaBasal meningitisIvh -> irritating fourth ventricleLateral medullary infarct (vestibular

25. ExaminationGeneral physical examinationEvidence of external injuryColour of skin and mucosaOdour of breathEvidence of systemic illnessHeart lung

26. Neurological examinationFunduscopyPupil size and response to lightOcular movementsPosture and limb movementReflexes

27. CirculationKocher-Cushing response - rise in BP->bradycardia due to rise in ICP -> compression of floor of the iv ventricle fall in BP and tachycardia usually terminal event due to medullary failure

28. BreathingForebrain Post hyperventilation apneaCheyne stoke respirationHypothalamus midbrainCentral neurogenic hyperventilationBasis pontisPseudobulbar paralysis of voluntary center

29. Breathing in comaLower pontine tegmentumApneustic breathingCluster breathingShort cycle periodic breathingAtaxic breathingMedullaAtaxic breathingSlow regular respirationGasping

30. Breathing: Key pointsBreathing patternsSupratentorial - Cheyne-StokesHigh brain stem - Central hyperventilationLow brain stem - Ataxic (irregular)Least useful sign because:Acid-base derangementsHypoxiaCardiac influences

31. Cranial Nerve ExamSystematic assessment of brainstem function via reflexesCranial Nerve ExamPupillary light response (CN 2-3)Occulocephalic/calorics (CN 3,4,6,8)Corneal reflex (CN 5,7)Gag refelx (CN 9,10)

32. Pupils: AnatomyAfferent Limb: Optic NerveEfferent Limb: Parasympathetics via occulomotorMidbrain integrity/ tectumUncal Herniation (3rd nerve dysfunction)Pupillary resistance to insultParasympatheticHypothalamus

33. Pupils: Key pointsSize dependent on sympathetic and parasympathetic inputAnatomically near the RASResistant to metabolic influencesSmall and reactive with metabolic causesUnilateral dilation indicates uncal herniation

34. PupilAtropineOpiateOrganophosphorus

35. PupilDiencephalic (metabolic) Small reactiveMidbrain tectal Midsize,fixedMidbrain nuclear Irregular pear shaped3rd nerve Fixed widely dilatedPontine Pinpoint reactiveOpiate PinpointOrganophosphorus SmallAtropine Wide dilated

36. Eye movements: ExamPosition at restStraight aheadDysconjugateConjugate deviationOculocephalic reflexPositive “Doll’s eyes”Negative “Doll’s eyes”Oculovestibular reflexCold caloricsResting positionMidlineDeviation suggests frontal/pontine damageConjugateDysconjugance suggests CN abn.MovingRoving, dipping, bobbing

37. Eye movementMetabolic Roving eye movement,Oculocephalic,VestibuloocularSupratentorial Contralateral conjugate palsyThalamusUpper turn down

38. Eye movements in ComaMidbrainIpsilateral 3rdPontineIpsilateral 6thIpsilateral gaze palsyOne and half syndromeBilateral gaze palsyOcular bobbingMlf syndrome

39. Eye movements: AnatomyRL

40. Eye movements: ExamOculocephalic reflexEye response to head turningProprioception from the neck triggers the pontine conjugate eye centerDoll’s + or -?Smart brainDumb brain

41. Eye movements: ExamOculovestibular reflexEye response to cold water on the tympanic membraneHorizontal semicircular canal stimulation triggers the pontine conjugate eye centerNystagmusCOWSSmart brainDumb brain

42. Caloric reflexEnsure TM integrityElevation of head to 30 degrees (so that lateral semicircular canal is vertical)Instillation of up to 120 ml of ice waterAwake: deviation toward,nystagmus awayComatose: deviation towardWait 5 minutes, do other earWatch for conjugance of deviationTo test vertical eye movementsBoth ears, cold water-downward gazeBoth ears, warm water-upward gaze

43. Eye movements: Key pointsSymmetric responses seen with metabolic or structural causesAsymmetric responses seen with structural causesThe hemispheres (smart) are responsible for:Inhibiting Doll’s eyesFast component of nystagmusThe brain stem (dumb) is responsible for:Allowing Doll’s eyesSlow component of nystagmus

44. Motor Exam Key Points:Assess tone, presence of asterixisResponse to painful stimulinoneabnormal flexorabnormal extensornormal localization/withdrawalSymmetric responses seen with metabolic or structural causesAsymmetric responses seen with structural causes

45. PostureCerebral hemisphere Decorticate postureDiencephalon supratentorial Diagonal postureUpper brain stem Decerebrate posturePontineAbnormal ext armWeak flexion legMedullaryFlaccidity

49. InvestigationComplete blood count, MP, B.sugarBlood urea, s. creatinine, s.electrolyteBlood gases, ALT, ASTCSF examinationCT scan/ MRIX-ray chest, ECG

50. ECG changes in coma(SAH, ICH, INFARCT)Tall T, prolonged QTQ wave with st depressionSVT, AF, AFLSinus bradycardia,arrest, nodal rhythmA-V block or dissociationPVc's, VFL, VF

51. Agitated ReassuranceNarcoticsSmall doses administeredIntravenouslySedationShould follow analgesia

52. Sedation in presence of pain causes agitation,

53. Titrate intravenously so that agitation is blunted,

54. Do not induce excessive drowsinessAgitated patient General managementFace a window for day/night orientation

55. Clock, calendar

56. Have friend or family member stay with patient

57. Light the room if illusions, paranoia occur at night

58. Provide eyeglasses, hearing aids

59. Have staff identify themselves to patient

60. Explain all procedures

61. Provide radio, reading, TVComa Subsequent managementEye, mouth, skinFluid electrolyte, feedingRespiration, circulationUrine, bowelStimulationInfection

62. Thank You