Transcript General Emergent Management of Patients with Acute

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
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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
smoking
diabetes
African-American
TIA
previous stroke
atrial fibrillation
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
– Barthel index
normal
– Glasgow outcome
0-5, 0 = normal
100, 100 =
0-5, 5= normal
• in NINDS t-PA stroke trial, 0 = normal
Stroke Scales
• NIH stroke scale 0-42
0-5
mild/minor in most patients
5-15
moderate
15-20 moderately severe
> 20
very severe
underestimates volume of infarct in nondominant (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
seizure
trauma
mass lesions
vascular disorders
infections (endocarditis)
complex migraine
metabolic abnormalities
Stroke Vital Signs
Airway
Breathing
Circulation
C-spine
Glucose
Temperature
Airway Management
Upper 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
Autoregulation
of Cerebral Blood Flow
Ischemic
80
Normotensive
60
Hypertensive
40
20
MAP
mm Hg
25
0
20
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15
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10
0
50
0
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CBF ml/100mg/min
100
Hypertension
Ischemic Stroke
• Loss of autoregulation
• Treat judiciously if at all
• Treatment guidelines - not receiving rtPA
– AHA: MAP > 130 or Sys BP > 220
• MAP= [(2x DP)+SP]B3
– 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
• Enalapril
Oral: 2.5 - 5.0 mg/day, max 40mg/day
IV : 0.625-1.25 mg IV Q 6hrs, max 5.0 Q 6
hrs
Hypertension -Ischemic Stroke
• Nitroglycerine
Paste: 1-2 inches to skin
IV Drip: 5mcg/min, increase in increments of
5-10mcg every 3-5 min
• Nitroprusside
IV Drip: 0.3 - 10 mcg/min/kg
Continuos BP monitoring
check 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
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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 strokes
cortical involvement
unstable tissue at risk
spreading depolarizations
hx 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
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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
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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