Medicine 536 Introduction to Critical Care Medicine January 28, 2014 Andrew M. Luks, MD Associate Professor Pulmonary and Critical Care Medicine

The Bulk Of The Focus Of Neurocritical Care Unlike in other aspects of critical care, shock and respiratory failure are not the core problems with which you deal

Case 1 A 56 year-old woman complains of the sudden onset of a severe headache and then becomes obtunded and difficult to arouse. Her daughter calls 911 and she is brought to the ER where she is afebrile with a BP 189/105 and HR of 110. On exam, she opens her eyes to painful stimuli, is only moaning and demonstrates abnormal flexion with deep painful stimuli.

Her Head CT Scan

Case 2 An 24 year-old man is brought to the emergency room with altered consciousness after being struck in the head several times during a fight in a bar. On exam, he is somnolent. He flexes his extremities to pain, does not open his eyes to voice or painful stimuli and is not making any speech.

His Head CT Scan

Case 3 An 63 year-old man with a history of a heart transplant falls out of bed in the middle of the night. His wife notices that he is not speaking and calls 911. In the ER, he is not speaking. He is not moving the right side of his body and has an up- going toe and triple flexion response on the right side.

His Head CT

His Head CT 12 Hours Later

Case 2 Diagnosis: Case 3 Diagnosis: Case 1 Diagnosis: What The Primary Problems Subarachnoid Hemorrhage Epidural Hematoma Ischemic Infarction

Other Problems That Require Neurocritical Care Status epilepticus Acute spinal cord injury Intraparenchymal hemorrhages Acute subdural hematomas Acute neuro- muscular disease Mass effect from intracranial tumors Neuro ICU Brain contusion

A Question What’s your differential diagnosis for the patient presenting with an acute change in their mental status?

The DDx For Acute Mental Status Changes CNS infectionHypertensive encephalopathy CNS mass lesionHyponatremia CNS traumaHypoxemia Hepatic encephalopathyMedication side-effects HypercalcemiaNon-CNS infection HypercarbiaNon-convulsive seizures HypoglycemiaShock HypernatremiaSubstance ingestion Diagnoses in orange are those that require admission to the neuro-intensive care unit

A Key Principle Of Patient Evaluation In The Neuro ICU Mental status changes (as well as other aspects of the neurologic exam) are often the first sign that something has changed for the worse with your patient

Communicating About Mental Status: The GCS Eye OpeningVerbal Response Motor Responses Spontaneous4Oriented5Follows6 To speech3Confused4Localizes5 To pain2Misused words3Withdraws4 Never1Incomprehensible2Flexion3 None1Extension2 None1 The Glasgow Coma Score (GCS) is the sum of the score on each dimension

Let’s Go Back To Case 1 A 56 year-old woman complains of the sudden on set of a severe headache and then becomes obtunded. On exam, she opens her eyes to painful stimuli, is only moaning and demonstrates abnormal flexion with deep painful stimuli. What’s her GCS?

Let’s Go Back To Case 1 A 56 year-old woman complains of the sudden onset of a severe headache and then becomes obtunded. On exam, she opens her eyes to painful stimuli, is only moaning and demonstrates abnormal flexion with deep painful stimuli. What’s her GCS? Eye opening: 2 Verbal: 2 Motor: 3 GCS = 7

Other Ways We Assess Mental Status What’s your full name? What’s the date? Where are you? The mini-mental status exam is not useful for assessing acute changes in mental status

A Critical Issue In Brain Injury ICP Intracranial Pressure Questions: What is your ICP? ____________ At what level is intervention needed? ____________ 7-15 mmHg > 20 mmHg

Methods To Measure ICP The ventriculostomy is the gold-standard; Intra- parenchymal devices are more commonly used with traumatic injury Source: BMJ : 110

An Example Of An Intraparenchymal Monitor

The Physiology Behind ICP Problems Brain Tissue Blood CSF The intracranial compartment has three components that reside in a fixed space

The Physiology Behind ICP Problems CSF Blood Brain Tissue If the size of one component increases, the volume of the others must shrink or ICP will rise* * This is often referred to as the “Munroe-Kellie” doctrine

The System Has A Limited Ability to Compensate Intracranial Pressure Intracranial Volume Compensatory mechanisms exhausted Compensatory mechanisms active

Examples Of These Compensatory Mechanisms Note the missing ventricles on one side… The CSF has been squeezed out.

Consider This Case A 39 year-old man presents to the ER with headache, nausea and vomiting 5 hours after being struck on the head by a golf club. On CT scan, he has a left-sided subdural hematoma. During his evaluation in the ER, he was noted to develop left hemiparesis, a fixed and dilated pupil on the left and increasing somnolence. What’s going on with this patient?

Why We Care About High Intracranial Pressure Sustained Increase in ICP (normal < mm Hg) Mass Effects & Herniation Impaired Perfusion

Herniation Syndromes Supratentorial 1.Uncal 2.Central 3.Cingulate 4.Transcalvarial Infratentorial 5.Upward 6.Tonsillar Image Source: Wikipedia.org

How Increased ICP Affects Cerebral Blood Flow Normal ICP Cranium CBF Cranium High ICP CBF High ICP

The ICP is Not the Only Variable That Matters Cerebral Perfusion Pressure Mean Arterial Pressure Intracranial Pressure = - Goal CPP: > 60 mm Hg CPP

How Focusing on CPP Affects Your Thinking Variable Scenario 1 Scenario 2 Scenario 3 ICP MAP CPP Outcome

Managing Increased ICP: Decrease Blood Volume Supine Semi-recumbent (> 30°)

Managing Increased ICP: A Role For Hyperventilation? Cerebral Blood Flow Arterial PCO 2 (mm Hg) Due to risk of decreasing perfusion too much, this is now reserved for acute decompensation

Managing Increased ICP: Decrease Oxygen Demand Cerebral Oxygen Demand Cerebral Blood Flow  The implications: treat and prevent fever, seizures; sedate the patient

Managing Increased ICP: Hyperosmolar Therapy Brain Tissue Blood Vessel H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O Increase Tonicity Here Two Options Mannitol Hypertonic Saline

When Medical Management Fails… Malignant MCA Infarction Decompressive Craniectomy

A BIG Take-home Message in the Neuro ICU It’s often not the initial insult that does the patient in, but the secondary insults that occur later which do the most harm

Secondary Insults That Can Affect Patient Outcomes Hypoxia Hypercarbia Hypotension Fever Hypocarbia Brain Injury

Secondary Insults Put Bad Cycles In Motion  CPP  ICP  LOC LOC: Level of Consciousness  Cerebral Blood Volume Airway Compromise  PCO 2  PO 2

Pulmonary Complications in Severe Head Injury 37 year-old man: sub- arachnoid hemorrhage Differential Diagnosis Aspiration pneumonitis Neurogenic pulmonary edema Cardiogenic pulmonary edema Acute respiratory distress syndrome

Several Forms Of Shock Occur In The Neuro ICU Type of Shock Trigger Cardiac Output SVR Neurogenic Spinal cord injury Cardiogenic * Severe head injury Septic Line infection; Pneumonia HighLow HighLow HighLow * This is often called a Takotsubo cardiomyopathy

Endocrinology Problems: Altered Sodium Regulation 54 year-old woman with hyponatremia (Na + = 132) 5 days following a subarachnoid hemorrhage Urine sodium: 25 Serum Osm: 275 Urine Osm 450 The Diagnosis: __________________ SIADH

Endocrinology Problems: Altered Sodium Regulation 35 year-old woman copious urine output (> 500 mL/hr) 1 day following severe traumatic brain injury Urine SG: Serum Osm: 300 Urine Osm 80 The Diagnosis: __________________ Diabetes Insipidus

The Take-Home Messages On Neurocritical Care Altered mental status is an important vital sign for the central nervous system Intracranial hypertension increases the risk of herniation and ischemic injury Secondary injuries and insults significantly increase the risk of poor patient outcomes

Case 1 A 30 year-old roofer is found on the ground next to a house, crawling on his hands and knees. He is awake but confused. His co-workers call 911 and he is brought into the ER where he has a BP 149/53, HR 108 and a RR of 16. On exam, he withdraws to painful stimuli, opens his eyes to voice but is not making comprehensible speech.

His Head CT

Case 3 Diagnosis: Case 4 Diagnosis: Case 2 Diagnosis: Case 1 Diagnosis: What Are These Patient’s Primary Problems Frontal Contusion Subarachnoid Hemorrhage Epidural Hematoma Ischemic Infarction

Secondary Insults Put Bad Cycles In Motion  CPP  ICP  Cerebral Vasodilation  Cerebral Blood Volume  MAP

Let’s Go Back To Case 1 A 30 year-old roofer is found on the ground next to a house, crawling on his hands and knees. He is awake but confused. On exam, he opens his eyes to voice, is not making comprehensible speech and withdraws to painful stimuli. What’s his GCS?

Let’s Go Back To Case 1 A 30 year-old roofer is found on the ground next to a house, crawling on his hands and knees. He is awake but confused. On exam, he opens his eyes to voice, is not making comprehensible speech and withdraws to painful stimuli. What’s his GCS? Eye opening: 3 Verbal: 2 Motor: 4 GCS = 9

Secondary Insults Put Still More Bad Cycles in Motion Bridging Veins

Secondary Insults Put Still More Bad Cycles in Motion  Cerebral Blood Volume Compress Bridging Veins Decreased outflow of blood  ICP

Brain Injury Can Affect The Rest of the Body