Breathing for the Head
John Peterson, DO
KU School of Medicine - Wichita
Disclosures
• I’ve known Alan and Jeff for a while……
Objectives
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Neurological injuries
Physiological effects
Airway management
Ventilator management
Neurological injuries
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Disturbances in consciousness
Encephalopathy
Traumatic brain injury
Acute Myelopathy
Ischemic stroke
Intracerebral hemorrhage
Subarachnoid hemorrhage
Brain tumors
Status epilepticus
Venous thrombosis
– Cerebral Sinus
– DVT/PE
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011. pp xi - xiii
Disturbances in Consciousness
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Drowsy
Stupor
Minimally conscious state
Vegetative state
– Restored sleep/wake cycle
• Locked – in syndrome
• Coma
• Brain death
Encephalopathy
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Vascular
Trauma
Neoplasm
Seizure
Organ Failure
Metabolic
Endocrine
Pharmacologic
CNS infection
Systemic infection
Inflammatory and immune – mediated encephalitis
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011, p 289
Traumatic Brain Injury
• Primary injury
• Secondary injury
– May be more injurious
– Hypoxia and hypoperfusion most likely are the
most critical factors in secondary injury
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011, p 308
Acute Myelopathy
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Traumatic
Degenerative spine
Neoplastic
Inflammatory
Systemic disease
Bacterial and viral infections
Vascular
Toxic/Metabolic
Stroke
• Defined
– Focal neurological deficit that has an arterial
distribution that correlates with specific region of
the brain
Normal Brain
Ischemic stroke
• Focal neurological deficit corresponding to
arterial territory
• Transient ischemic attack (TIA)
– Symptoms resolve in less than 24 hrs
• Typically less than 1 hr
• Reversible Ischemic Neurologic Deficit (RIND)
– Symptoms lasting 24 – 72 hrs
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011, p 341
Ischemic Stroke
Ischemic stroke
• Embolic
– Cardiac
– Artery to artery embolus
– Paradoxical embolus
• Thrombotic
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Intracranial atherosclerosis
Lipohyalinosis
Arterial dissection
Arteritis
Fibromuscular dysplasia
Vasospasm
Hypercoaguable states
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011, p 342
Ischemic Stroke
• Modifiable
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Diabetes mellitus
Hypertension
Smoking
Hypercholesterolemia
Coronary artery disease
• Non-modifiable
– Age
– Male
– Family history
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011, p 342
Intracerebral Hemorrhage
Intracerebral Hemorrhage
• 10 – 15% of all strokes
• 30 day mortality: 35 – 52%
• Only 20% are independent functional at
6 months
• Etiology
– Primary
• Secondary to hypertension
– Secondary
• Aneurysmal, AVM, Tumor, Amyloid angiopathy,
Coagulopathies, Trauma
Intraventricular Hemorrhage
Subarachnoid Hemorrhage
• Trauma
– Most common cause
• Spontaneous
– 80% Aneurysmal
– 10 – 15% Perimesencephalic nonaneurysmal
hemorrhage
– 5% Nonaneurysmal
• 2 – 5% of all strokes
Subarachnoid Hemorrhage
Vasospasm
• Occurs between days 4 -12
– Lasts up to 21 days
• Monitoring with transcranial doppler (TCD)
• Treatment for symptomatic vasospasm
– Triple H
• Hypertension
• Hypervolemia
• Hemodilution
– Angiography with balloon dilation or intra-arterial
calcium – channel blocker infusion
Epidural Hematoma
Subdural Hematoma
Post-Cardiac Arrest Brain Injury
• Therapeutic hypothermia
– Indicated for out-of-hospital ventricular fibrillation
arrest
– Possible benefit with asystole and PEA
– 55% of the hypothermia group had a favorable
outcome vs 39% in the normothermia group
• At 6 months 41% of the hypothermia group died vs 55%
of the normothermia group
Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011, p 393
Venous Thrombosis
• Cerebral Sinus
– Rare cause of stroke
• Thrombophilia is most common cause
• Systemic anticoagulation required
• DVT/PE
– 79% of pulmonary embolism originates from a lower
extremity deep vein thrombosis
– Neurological conditions predisposing to VTE
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Spinal cord injury
Traumatic brain injury
Ischemic stroke
Intracerebral hemorrhage
Malignant glioma
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 433-434, 506-507
Venous Thrombosis
• Deep Vein Thrombosis
– Risk Factors
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Venous valvular insufficiency
Right-sided heart failure
Postoperative period
Prolonged bedrest
Extremity trauma
Malignancy and cancer therapy
Pregnancy and postpartum period
Hormone therapy
Spinal cord injury
History of venous thromboembolism
Hypercoagulable state
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 506-507
Malignant Hyperthermia
• Autosomal dominant condition
• Triggers
– Halogenated inhalational anesthetics
– Succinylcholine
– Extreme stress, vigorous exercise and heat
exposure
• Risk Factors
– Myopathies
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 437
Malignant Hyperthermia
• Signs and symptoms
– Unexpected rise in end-tidal CO2 > 55 or
PaCO2 >60
– Increased minute ventilation
– Unexplained tachycardia, ventricular tachycardia or fibrillation, labile
blood pressure, congestive heart failure
– Metabolic acidosis with elevated serum lactate
– Altered mental status (when anesthetic is stopped)
– Generalized muscle rigidity, masseter rigidity (despite neuromuscular
blockade), rhabdomyolysis
– Acute renal failure
– Hyperkalemia
– Hyperthermia (Temperature can rise 1 – 2 C˚ q 5 min up to 44˚C)
• This is a late finding
– DIC
• Especially with temp > 41˚C
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 438
Malignant Hyperthermia
• Management
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Stop offending agent
Admit to ICU
Increase minute ventilation to normalize PaCO2
Body cooling
• NG icy lavage, ice packs, fans, surface or invasive cooling
systems
• Target temp of 38.5
– Dantrolene
• Continue for 3 days IV or PO dosing
• Monitor for excessive muscle weakness or hepatotoxicity
– Monitor for recrudescence
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 438
Neuroleptic Malignant Syndrome
• Risks
– Prior physical exhaustion and dehydration
– Previous episode of NMS
– Exposure to antipsychotic drugs
• Signs and symptoms
– Develop within 24hrs – 1 month after exposure to
antipsychotic drugs
– Regression within 1 wk – 1 month after
discontinuation of drug
• 10% Mortality
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 435-436
Brain Tumors
• Second most common cause of death from intracranial disease
• 33% overall 5 year survival
• 33% of all tumors are gliomas
– 67% are high grade
• Metastatic tumors are the most common brain neoplasm
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Lung (18 – 64%)
Breast (2 – 21%)
Melanoma (4 – 16%)
Colorectal tumors (2 – 12%)
Renal cell carcinoma (1 – 8%)
Lymphoma (< 10%)
Unknown origin (1 – 18%)
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 445-446
Brain Tumors
Brain Tumor
Brain Tumors
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Headache
Seizure
Progressive focal neurological deficits
Visual defects
Altered mental status
Intracerebral hemorrhage
Intracranial pressure elevation
Hydrocephalus
• Caused by impaired cerebrospinal fluid flow,
reabsorption or excessive production
• Cerebrospinal fluid
– Forms at 0.3mL/min
• 20mL/hr
• 500mL/day
– Total volume ~150mL
• 75mL in cranial vault
– Normal pressure ~10mmHg
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 469. 471
Hydrocephalus
Hydrocephalus
Neuromuscular Disorders
• Acute generalized weakness
– CNS
• Bilateral hemispheric
• Brainstem
• Spinal cord
– Motor neuron
• West Nile infection
• Poliomyelitis
• Enterovirus infection
– Neuromuscular junction
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Myasthenia gravis
Lambert-Eaton myasthenic syndrome
Organophosphate poisoning
Botulism
Tick Paralysis
Hypermagnesemia
Snake/insect/marine toxins
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 478
Neuromuscular Disorders
• Acute generalized weakness causes cont.
– Neuropathies
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Guillain – Barré syndromes
Critical illness polyneuropathy
Chronic idiopathic demyelinating polyneuropathy
Toxic neuropathies
Vasculitic neuropathy
Porphyric neuropathy
Diptheria
Lymphoma
Carcinomatous meningitis
Acute uremic polyneuropathy
Eosinophilia-myalgia syndrome
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 478
Neuromuscular Disorders
• Acute generalized weakness causes cont.
– Myopathies
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Critical illness myopathy
Dermatomyositis
Polymyositis
Periodic paralysis/hypokalemic myopathy
Myotonic dystrophy
Acid maltase deficiency
Muscular dystrophies
Mitochondrial myopathies
Corticosteroid-induced myopathy
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 478
Neuromuscular Disorders
• Causes of acute respiratory muscle weakness
– CNS
• Diseases of high cervical cord or medulla
– Motor neuron disease
– Neuromuscular junction
• Myasthenia gravis
• Lambert-Eaton myasthenic syndrome
– Neuropathies
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Idiopathic bilateral phrenic nerve paresis
Guillain-Barré syndrome (rare)
Neuralgic amyotrophy
Large artery vasculitis
Multifocal motor neuropathy
– Myopathies
• Acid maltase deficiency
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 478
Neuromuscular Disorders
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Causes of acute predominantly bulbar weakness
– CNS
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Brainstem diseases
Bilateral white matter diseases
Syrinx
– Motor neuron
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Amyotrophic lateral sclerosis
Kennedy disease
– Neuromuscular junction
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Myasthenic gravis
Lambert-Eaton myasthenic syndrome
Botulism
– Neuropathies
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Guillan-Barré syndrome (rare)
Carcinomatous meningitis
Skull base tumor or metastases
Miller-Fisher disease
Sarcoidosis
Basilar meningitis
– Myopathies
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Dermatomyositis
Polymyositis
Oculopharyngeal muscular dystrophy
Myotonic dystrophy
Distal myopathy with vocal cord paralysis
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 479
Neuromuscular Disorders
• Acute failure of the autonomic nervous system
– CNS
• Diseases affecting the hypothalamus, brainstem, medulla, high cervical cord
• R insular stroke
– Neuromuscular junction
• Lambert-Eaton myasthenic syndrome
• Botulism
– Neuropathies
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Diabetic autonomic neuropathy
Amyloid neuropathy
Guillain-Barré with predominant dysautonomia
Paraneoplastic dysautonomia
Connective tissue disorders
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Sjogrens
Systemic lupus erythematosus
Infectious
Chagas
HIV
Leprosy
Diptheria
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 479
Neuromuscular Disorders
• Indications for ICU admission
– Respiratory weakness
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FVC < 40ml/kg
NIF < - 40 cmH2O
> 30% decline in FVC or NIF in 24 hrs
Signs of fatigue or dyspnea
Significant neck flexor weakness or poor cough
CXR
– Infiltrates, atelectasis or pleural effusion
– Dysphagia/inability to protect airway
• Increased aspiration risk
• Bulbar dysfunction/bilateral facial weakness
• Failed swallow evaluation
– Autonomic instability
• Dysrhythmia
• Blood pressure lability
• Profound sensitivity to sedatives
– Planned interventions
• Plasma exchange
• Frequent vital checks or intensive nursing care
• Rapid onset of symptoms (< 7 days)
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 480
Neuromuscular Disorders
• Intubation indications
– Consider early intubation
• May reduce pulmonary complications
– FVC < 20 mL/kg
– NIF < - 30 cmH2O
– PaO2 < 70 (decrease by > 50% in 24 hrs) on room
air
– Hypoventilation (PaCO2 > 45)
– Dysphagia
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 480
Neuromuscular disorders
• Extubation criteria
– Pressure support of 5 with PEEP 5 for > 2hrs
(prolonged SBT)
– Some evidence for PS of 0 with PEEP of 5 or Tpiece predicts more successful extubation
– Successful secretion management
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 481
Status Epilepticus
• A seizure that persists a sufficient length of time
or is repeated frequently enough to produce a
fixed and enduring epileptic condition
• Historically, is defined by a seizure lasting 30 min
and should be considered for seizures lasting 5 –
10 min
• Nonconvulsant status epilepticus should be
considered with coma patients with unclear
etiology
– May occur in as many as 8 -34% of critically ill patients
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 489
Status Epilepticus
• Etiologies
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Neurovascular
Tumor
CNS Infection
Inflammatory disease
Traumatic brain injury
Primary epilepsy
Hypoxia/ischemia
Drug/substance toxicity or withdrawl
Fever
Metabolic abnormalities
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 491
Status Epilepticus
• Medical treatment
– May require inducing a coma
– Neuromuscular blockade
• Will not stop the seizure, only the motor manifestation
• Airway and ventilator management
– May not be required for nonstatus seizure
– Will be required for induced coma
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 499
Spinal Cord Injury
• Trauma is the most common cause
– ~ 50% are motor vehicle related
– 24% related to falls
– 9% sports injury
– 11% assault
– > 50% involve the cervical spine
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 325
Spinal Cord Injury
• Diaphragm
– Innervated by cervical spine segments C3 – C5
• Injury at or above this level results in immediate
ventilatory failure
– Below the diaphragmatic level
• Diaphragm is preserved
• Intercostals are compromised
• Decreased vital capacity, maximal inspiratory support
and decreased expiratory force
• Spasticity develops leading to improved forced vital
capacity and maximal expiratory force
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 333
Spinal Cord Injury
• Post injury
– Rapid shallow breathing
transiently compensates
for the injury
– Atelectasis develops
– 1/3 will require intubation
– Consider intubation when
VC < 1L
– Intubate if decreased LOC,
impaired cough or unable
to manage secretions
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 333
Neurogenic Pulmonary Edema
• Occurs in with severe acute neurological injury
• Incidence
– 40% of head injury patients
– 90% intracerebral hemorrhage
Neurological evaluation
Neurological Evaluation
Bhardway, Anish, et. al., ed,
Handbook of Neurocritical Care,
2nd ed. Springer, 2011, p 313
Physiological Effects
of
Neurological Injury
• Cerebral Blood Flow
– Controlled by the arteriole constriction and
relaxation
• Hypoventilation
– Hypercarbia
– Hypoxia
Autoregulation
metrohealthanesthesia.com
Cerebral Perfusion Pressure (CPP)
• CPP = Mean arterial pressure (MAP) –
Intracranial pressure (ICP)/Central venous
pressure (CVP)
Monro-Kellie Doctrine
Monro-Kellie Doctrine
Hyperventilation
• PaCO2
– 1 mmHg change in PaCO2 produces
1 ml/100 Gm/min change in CBF (in same
direction)
• Transient effect (wanes in 6-8 hours)
• Normal CBF
– PaCO2 = 40 mmHg
Management
• ABC
– Airway
• GCS < 8 or rapid worsening GCS
• Uncontrolled seizures
– Intubation
• Controlled induction
– Avoiding hypo or hypertension
– Consider lidocaine to blunt elevation in ICP
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 357
Management
• ABC
– Breathing
• Higher mortality rate in neurological patients than
nonneurologic patients despite a lower incidence of
extracerebral organ dysfunction
• Avoiding secondary injury
– Lung Protective Ventilation
– Circulation
• Target CPP 60 – 80 mmHg
– ICP monitoring
• Necessary to accurately measure CPP
Pelosi, et. al. Crit Care Med 2011 Vol. 39,
No. 6
Ventilator management
• Mode
• PEEP
• Oxygenation
– O2 saturation > 90%
– PaO2 > 60 mmHg
• ARDS
– Lung protective ventilation
• Neurogenic pulmonary edema
Bullock, R, M.D., Ph.D., Deputy Editor, Povlishock, J., Ph.D. Editor-in-ChiefGuidelines for the Management
of Severe Traumatic Brain Injury of Severe Traumatic Brain Injury 3rd ed, 2007 Brain Trauma Foundation,
Inc.
PEEP
• PEEP
– Increases
• Intrathoracic pressure
• Peak inspiratory pressure
• Mean airway pressure
– Decreases
• Venous return
• Mean arterial pressure
• Cardiac output
PEEP
• PEEP 5 – 15 mmHg
– Generally tolerated in patients at risk for elevated
ICP
– Elevated ICP should be closely monitored with
changes in PEEP
Venous Drainage
Extubation
• Neurosurgical patient
– GCS = 4 were successfully extubated
• Intact cough and gag
– Strategy
• Is the neurological injury reversible?
• What is the duration of injury?
– If long term neurological injury anticipated
• Early tracheostomy
Extubation
• Criteria
– Signs of appropriate muscle strength
– Vital capacity > 15 – 20 mL/kg
– Mean inspiratory pressure < -20 to -50 cmH2O
– FiO2 < 40% and PEEP ≥ 5 cmH2O
– No fever, infection or other medical complications
Pulmonary toilet
• Endotracheal suctioning on cerebral
oxygenation in traumatic brain-injured
patients
– Increased ICP
– Increased CPP
– No change in oxygenation
Kerr, et al, Critical Care Medicine, Volume 27(12), December 1999, pp
2776-2781
Monitors
• ICP Monitors
– Bolt
• Pressure monitor
– External Ventricular Drain (EVD)
• Pressure monitor
• Drainage of CSF
– Parenchymal ICP monitor (Codman)
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 314 - 315
Monitors
• Tissue oxygenation
– Jugular venous saturation
– Brain tissue oxygenation (Licox)
– Near – infrared spectroscopy
• Tissue metabolic activity
– Microdialysis catheter
Bhardway, Anish, et. al., ed, Handbook of Neurocritical
Care, 2nd ed. Springer, 2011, p 314 - 315
Summary
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Recognition of neurological injury
ABCs
Intubation and Ventilation
Extubation
References
1. Bhardway, Anish, et. al., ed, Handbook of
Neurocritical Care, 2nd ed. Springer, 2011.