Neurologic Dilemmas in the ICU

1. Neurologic Dilemmas in the ICU Nerissa U. Ko, M.D. Neurovascular and Neurocritical Care University of California, San Francisco

2. Objectives Diagnosis of neurologic causes of altered mental status and coma Physical exam findings Role of imaging and adjunctive tests Neuroprotective management strategies for the comatose patient Treatment of seizures in the ICU Approach to neuromuscular causes of respiratory failure Physical exam findings Management strategies Role of diagnostic tests

3. Case #1: Sudden Onset Coma 58 year-old woman with hypertension complained of sudden headache, vomited, then slumped forward. In the E.D. her vitals were: BP 160/90, HR 105, T 37.5. She remained unresponsive, no eye opening to stimulation.

4. EVALUATION OF COMA: Simon�s Rule of Four 1- First things to do ABCs Draw Blood D50% Narcan

5. Initial Management Goal is to protect the brain while getting to the diagnosis airway ventilation blood pressure management neurologic diagnosis may affect early management Maintain adequate perfusion pressure Consider elevated ICP Seizures CNS infection, mass lesions

6. Airway Management in Coma Preoxygenate Premedicate Lidocaine 1.5 mg/kg Fentanyl 50-250 �g Maintain Current BP Use of pressors: Neosynephrine 50-150�g Lower dose at induction: Thiopenthal 25-100 mg Rapid Sequence Intubation cricoid pressure follow BP Use of non-depolarizing neuromuscular blockade Ventilate TV 10-15 cc/kg @ 10-12/min keep CO2 constant

7. Treatment of Coma: Blood Pressure Diagnosis Unclear do not lower blood pressure Large Ischemic Stroke allow permissive HTN follow ECG, eye grounds, renal function typical BP <220/140 Intracranial Hemorrhage keep MAP <140 Aneurysmal SAH target normal BP for patient acutely

8. Treatment of Coma: Blood Pressure

9. EVALUATION OF COMA: Simon�s Rule of Four 1- First thing to do 2- Two Localizations of Coma Both Hemispheres Midbrain Reticular Activating System

10. EVALUATION OF COMA: Simon�s Rule of Four 1- First thing to do 2- Two Localizations of Coma 3- Three Etiologies Structural Metabolic Electrical (seizure)

11. Localization of Coma Supratentorial Downward herniation: rostral-caudal progression of deterioration Causes: stroke, hemorrhage, trauma, infection, tumor Exam: focal findings early, asymmetric motor signs, late respiratory findings Diagnosis: Needs imaging prior to other studies such as LP Subtentorial Upward herniation or tonsilar herniation Causes: stroke, trauma, tumor, demyelination, infection, hemorrhage Exam: sudden onset coma, brainstem findings, crossed motor findings, respiratory involvement, oculovestibular abnormalities CT can be normal

12. Metabolic Causes of Coma Drugs, toxins Insufficient substrate: oxygen, glucose, ischemia, thiamine Organ failure: liver, kidney, lung, endocrine, cardiac Other: electrolytes, acid-base, etc. Exam: Mental status changes before motor findings, reactive pupils, asterixis, tremors, seizures, hypo- or hyperventilation Diagnosis: CT typically negative, lumbar puncture, lab studies, toxicology screen, EEG

13. EVALUATION OF COMA: Simon�s Rule of Four 1- First thing to do 2- Two Localizations of Coma 3- Three Etiologies 4- Four things to Examine Pupils, Eye movement Respirations Response to Pain Meningeal Signs

14. Respiratory Changes

16. Herniation syndromes 1. Subfalcine 2. Subuncal 3. Tonsilar 4. Extracalverial

17. Case #1: 58 y/o sudden onset coma Respirations: The patient was breathing spontaneously but intubated for airway protection Pupils: Left pupil is dilated and sluggishly reactive Extraocular movements: Full movements to Doll�s maneuver Response to pain: Localized pain in all four extremities Meningeal signs: Mild neck stiffness

18. Case #1: Differential Diagnosis Differential Diagnosis Intracranial hemorrhage/ expansive lesion Ischemic Stroke Subarachnoid hemorrhage Meningitis Imaging study indicated for focal findings on examination Head CT: Best diagnostic test for excluding acute blood MRI: Best for evaluating posterior fossa

19. Case #1: Diagnostic studies

20. Case #1: 58 y/o woman with SAH The patient had her aneurysm treated. Her exam improved to spontaneous eye-opening and following commands. She continued to have anisocoria, with a sluggish left pupil. On hospital day #3, she was noted to have progressive somnolence, intermittently following commands.

21. Case #1: Differential Diagnosis Part II DDx: Rule #3 of Coma Structural: rebleed, hydrocephalus, stroke non-dominant parietal, dominant temporal, bifrontal, and bioccipital Metabolic: Hyponatremia, meningitis Electric: Non-convulsive status epilepticus, post-ictal state Psychogenic: severe abulia Exam Eyes closed, unresponsive Pupils dilated, sluggish �Nystagmus� Spontaneous movement to pain, R>L

22. Case #1: Studies Diagnostic evaluation: Head CT: mild hydrocephalus, no rebleeding; cannot exclude acute ischemia EEG: Diffuse slowing, occasional polyspike over R temporal region Labs: Na 125 mmol/L

23. Case #1: Treatment Treatment Trial ativan 1.0 mg IV at bedside, nystagmus stops Rapid correction of hyponatremia with 3% NaCl Extraventricular drain placed for hydrocephalus and ICP monitoring Transcranial doppler to rule out vasospasm

24. Treatment of Seizures in the ICU Brief, single seizure Observe, seizure precautions Eliminate identified etiology Consider course of anticonvulsants: phenytoin, carbamezapine Prolonged or >1 seizure Check vitals, immediate IV access Benzodiazepine: IV lorazepam, diazepam, midazolam Load with fosphenytoin Recurrent or refractory seizures (> 5-10 minutes) Consider as status epilepticus, ABCs Immediate IV benzodiazepine, concurrent load fosphenytoin Obtain EEG

26. Case #2: Unable to extubate 35 year-old man with a history of mild asthma. He had orthopedic back surgery requiring general anesthesia. He had no prior surgeries, and no other medical illnesses except a mild gastrointestinal illness two weeks ago. After surgery, he was noted to have significant airway edema and reactive airway disease. He remained intubated and transferred to the ICU. His oxygenation remained stable, but he became increasingly difficult to ventilate. He was sedated and paralyzed for better ventilatory control. In addition to aggressive treatments for bronchospasm, he was started on steroids.

27. Case #2: Generalized weakness in the ICU His reactive airway disease continued to improve. His sedation and paralysis were slowly decreased, and he was beginning to wean from ventilator support. At that time, nursing staff noted the patient had difficulty moving his limbs. Train of four showed 3/4 twitches. All sedatives and paralytic agents were discontinued.

28. Neurologic causes of weakness Brain Encephalopathy Multiple strokes Brainstem lesion Spinal cord Infarct Transverse myelitis Infection/compression Anterior horn cell ALS Polio Peripheral nerve Meningitis (radiculopathy) Critical illness Guillain-Barre syndrome Drugs, toxins Neuromuscular junction Persistent blockade Myasthenia gravis Botulism Muscle Acute quadriplegic myopathy Periodic paralysis, K+ Metabolic disorders

29. Clinical Features

30. Case #2: Differential Diagnosis Exam: Opens eyes to voice Pupils reactive, nl EOMs Neck flexor weakness Diffuse quadraparesis Reflexes decreased DDx: Prolonged neuromuscular blockade Acute myopathy Guillain-Barre Critical illness neuropathy

31. Diagnostic Studies Laboratory studies Electrolytes CPK Electrophysiology Nerve conduction studies EMG Biopsy Muscle Nerve

32. Case #2: Unable to wean from ventilator The patient was unable to wean from ventilatory support despite normal oxygenation and mild hypercarbia. His blood pressures became labile, and a full sepsis workup was initiated. On examination, he had severe facial weakness, absent reflexes and flaccid quadraparesis. Laboratory studies were normal. NCS/EMG suggested demyelinating neuropathy.

33. Case #2: Guillain-Barre Syndrome The patient was treated with IVIG for 5 days. He continued to have improved VC and MIF and was successfully weaned from vent support. His blood pressures stabilized after treatment. He required continued rehabilitation for his weakness.

34. Management Issues Respiratory failure Check VC, MIF q4-6 hrs Consider elective intubation VC< 20cc/kg, MIF< -30 Monitor hypercarbia Hypoxia is a late finding Dysautonomia Common cause of cardiovsacular collapse Vagal spells Arrhythmias Early telemetry monitoring Bedside pacer Pain Neuropathic pain May require narcotics Epidural anesthesia Prophylaxis for DVT/gastric ulcers Heparin/LMWH SQ H2 blocker/proton pump inhibitors Prevention of infection Nosocomial respiratory tract infection Urinary tract infection

35. Conclusions A disciplined approach to coma is necessary in the ICU Imaging studies have a higher yield in the setting of focal neurologic findings Diagnosis of seizures in the ICU can be difficult. Consider EEG early Aggressive treatment of status epilepticus, but often no need for prophylaxis and chronic therapy Neuromuscular syndromes are a common cause of ICU paralysis Electrodiagnostic studies can be useful Close monitoring of VC, MIF to determine need for intubation