general emergent management of patients with stroke, including blood pressure management

General Emergent Management of Patients with Stroke, Including

Blood Pressure Management

Objectives

• Review initial evaluation of the patient with an AIS– history, physical exam, diagnostics,

imaging

• Discuss acute supportive care– stroke vital signs: ABCC’s, hypertension,

glucose, temperature, seizure management

• Understand that emergent management requires simultaneous evaluation and intervention

Goals of Acute Supportive Care

Assure optimal perfusion and oxygenation

• Protect the C-spine• Secure the airway• Support oxygenation and

ventilation• Assure appropriate circulation

The History

• Age - approximately 65 yr• Sudden onset focal neurologic

deficit• Specific vascular territory• Seizure at onset of Sx: 5%• Headache at onset: 10-30%• Fall or trauma at onset

Time of Symptom Onset

• Most difficult portion of the history• Start when patient “was last seen

normal”• Work forward in time (TV guide)• Patients that awake with symptoms -

onset = time of sleep• Confirm with family, friends, care taker• EMS - bring family along in ambulance

Past Medical History

• Medications:– diuretic, antihypertensive, antithrombotic

• Risk Factors:hypertension TIAsmoking previous strokediabetes atrial fibrillation African-American carotid artery disease

Physical Exam

• Vital signs are vital, – but occasionally

inaccurate

• C-Spine tenderness, pain

• BP in both arms, symmetry of pulses

• Signs of trauma, associated injuries

• Neurologic deficit - characteristic vascular distribution

Stroke Scales

• Severity– NIH stroke scale 0-42, 0 = normal

valid, reproducible, assists in patient selection, facilitates communication

• Functional Scales– m-Rankin 0-5, 0 = normal – Barthel index 100, 100 = normal– Glasgow outcome 0-5, 5= normal

• in NINDS t-PA stroke trial, 0 = normal

Stroke Scales

• NIH stroke scale 0-420-5 mild/minor in most patients5-15 moderate15-20 moderately severe> 20 very severeunderestimates volume of infarct in

non-dominant (R) hemispheric strokes

Diagnostic Testing

• Laboratory studies– CBC, differential, platelets– electrolyte profile, glucose (finger

stick)– INR, aPTT– Troponin

• EKG• CXR

Non-contrast CT of the Head• Initial imaging study of choice• Readily available• Very sensitive for blood in the acute

phase– blood - 50-85 Hounsfield Units– bone- 120 (70-200) Hounsfield Units

• Not sensitive for acute ischemic stroke– nearly 100% sensitive by 7 days

• Posterior fossa structures - bone artifact

Non-contrast CT of the Head

• May shows early signs of ischemia in the 1st 3 hours– loss of gray/white matter distinction– hypodensity– mass effect, edema – hyperdense middle cerebral artery sign

• Re-evaluate the time of symptom onset, if early signs of ischemia are present

ECT

2 hours

24 hours

Other Imaging Modalities

• MRI– standard– DWI/PWI

• Xenon CT• Perfusion CT• CT Angiography

Differential Diagnosis

• Deciphered by history, PE, diagnostics

• DDx:TIA vascular disordersseizure infections

(endocarditis)trauma complex migrainemass lesions metabolic

abnormalities

Stroke Vital Signs

AirwayBreathingCirculation

C-spineGlucose

Temperature

Airway ManagementUpper airway patency

• Maintain C-Spine precautions• Asses level of consciousness • Inspect for loose dentures, foreign

bodies• Suction secretions • Assess gag reflex, tongue control

Oxygenation and Ventilation

• Respiratory rate and depth• Signs of fatigue - Paradoxical

respirations• Breath sounds - (CHF, pneumonia,

COPD)• Supplemental O2 with O2 sat > 95%• Support with Basic airway techniques• Ventilatory support as required

Basic airway techniques

• Foreign body removal

• Suction with rigid suction device

• Positioning– jaw thrust– chin lift

• Nasal airway• Bag valve mask

Advanced Airway Management

• Rapid sequence intubation, orotracheal– sedation and paralysis prevent increase in

ICP

• Most common indications– inability to maintain airway– depressed level of consciousness– need for hyperventilation to manage ICP

• Treat the underlying cause of respiratory distress: CHF, MI, etc.

Monitoring of oxygenation

• Pulse oximetry– indicator of oxygenation not

ventilation– falsely high in CO poisoning– falsely low in PVOD, hypotension,

peripheral vasoconstriction• ABG

– pCO2 allows eval of ventilation– obtain from compressible site

• Supernormal oxygenation– not of proven benefit

Circulation

• Goal: maintain cerebral perfusion• Optimize cardiovascular status• Monitor and reevaluate

Circulation

• Evaluate cardiac history and status

• Cardiac output– preload– afterload– contractility– stroke volume

Circulation

• Monitor vital signs Q 15 min in acute phase– pulse (palpate in all 4 extremities)– heart rate– rhythm – blood pressure (both arms)– central venous pressure

ECG

• Cardiac Arrhythmia: 5% -30%

• Acute MI: 1%-2%• ECG abnormalities

– more common with hemorrhagic infarct

– T-Wave inversions– nonspecific ST and T-wave

changes

Vascular Access

• Two peripheral IVs• Use .9NS or .45 NS

unless hypotensive• Use .9NS if hypotensive• Replace blood products

as indicated

Autoregulation

• The ability of the vasculature in the brain to maintain a constant blood flow across a wide range of blood pressures

• Autoregulation - impaired or lost in the area of the infarction

• Ischemic tissues are perfusion dependant

• Autoregulation is shifted to higher pressure patients with a history of HTN

0

20

40

60

80

100

0 50 100

150

200

250

MAP mm Hg

CB

F

ml/

100m

g/m

in Ischemic

Normotensive

Hypertensive

Autoregulationof Cerebral Blood Flow

Hypertension Ischemic Stroke

• Loss of autoregulation• Treat judiciously if at all• Treatment guidelines - not

receiving rt-PA– AHA: MAP > 130 or Sys BP > 220

• MAP= [(2x DP)+SP]3

– NSA: 220/115

Hypertension - Ischemic Stroke

• Drugs - short acting, titrate • Labetalol

IV: 10-20 mg increments, double dose Q 20 min, max cumulative dose 300mg

• EnalaprilOral: 2.5 - 5.0 mg/day, max 40mg/dayIV : 0.625-1.25 mg IV Q 6hrs, max 5.0

Q 6 hrs

Hypertension -Ischemic Stroke

• NitroglycerinePaste: 1-2 inches to skinIV Drip: 5mcg/min, increase in

increments of 5-10mcg every 3-5 min • Nitroprusside

IV Drip: 0.3 - 10 mcg/min/kgContinuos BP monitoringcheck thiocyanate levels

• AVOID NIFEDIPINE

Hypertension Intracerebral Hemorrhage

• Treat aggressively• Elevate head of bed• Use labetalol, nitroglycerine,

nitroprusside or lasix• AVOID NIFEDIPINE• Keep systolic < 160 mm Hg diastolic < 100 mm Hg

Hypotension

• More detrimental than hypertension• Seek cause and treat aggressively• CVP monitoring may be necessary• Use .9 NS first to ensure adequate

preload• Then add vasopressors if needed

Hypertension: rt-PA Candidate

• Exclude for persistent BP > 185/110

• Check BP q 15 min• May not aggressively lower BP to

meet entry criteria• Use Labetolol or Nitropaste• Avoid Nifedipine

Glucose

• Worse outcome after stroke:– diabetics– acute hyperglycemia at time of infarct

• Mechanism uncertain– increase in lactate in area of ischemia– gene induction, – increased number of spreading

depolarizations

• Insulin is a neuroprotective

Glucose

• Avoid any IV fluids with D5– instruct prehospital personnel not to

give D50 as part of the “coma cocktail” to acute stroke patients

• Check a finger stick ASAP – treat only if low (< 50)

• Use insulin to establish euglycemia

Temperature

• Fever worsens outcome:– for every 1°C rise in temp, risk of poor

outcome doubles (Reith, Lancet 1996)

• Greatest effect in the first 24 hours• Brain temp is generally higher than core• Treat aggressively with acetaminophen,

ibuprofen, or both• Search for underlying cause• Hypothermia currently under

investigation

Seizures

• Occur in 5% of acute strokes• Usually generalized tonic-clonic• Possible causes:

severe strokescortical involvement unstable tissue at riskspreading depolarizationshx of seizure disorder

Seizures• Protect patient from injury during ictus• Maintain airway• Benzodiazepines:

– lorazepam (1-2 mg IV)– diazepam (5-10 mg IV)

• Phenytoin: – 18 mg/kg loading dose, at 25-50 mg/min

infusion with cardiac monitor

• No need for prophylaxis

Primary treatment of AIS

• Supportive care• Aspirin• IV thrombolysis• No role for antithrombotics

Summary

Evaluation• History with time of symptom

onset• Physical exam

– trauma, NIHSS score

• Laboratory evaluation• Non-contrast CT head

Summary

Supportive Care• Secure airway; basic and advanced

methods• Protect C-spine• Assure oxygenation and ventilation• Maximize perfusion, IV fluids• Blood pressures (both arms), treat carefully• Normalize the temperature and glucose • Treat seizure if occurs• Reevaluate