11/1/2017

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Mitchell A. Ahrens, M.D. FCCP

Pulmonary, Critical Care, Sleep

CoxHealth, Ferrell-Duncan Clinic

Conflicts of Interest� None

Topics� Respiratory management

� Cardiovascular management

� Fever & Infectious issues

� Glycemic management

� Prophylaxis

� Nutrition

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Goals� Identify common respiratory issues with acute stroke

� Identify common cardiac and renal issues that may arise with acute stroke.

Positioning� Optimal positioning is unclear from studies.

� Lower SpO2 in supine position with comorbidities

� Cardiovascular or Pulmonary disease

� Obesity

� High risk patients recommended to keep HOB 15 – 30°

� Aspiration

� Intracranial hypertension

� Cardiac or pulmonary disease

Ref: 1.

Positioning

https://ars.els-cdn.com/content/image/1-s2.0-S0735109713022481-gr1_lrg.jpg

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Figure 1. MAP, ICP, and VmMCA on both sides in a 58-year old, medically treated patient with a left-sided complete MCA territory infarction.

Stefan Schwarz et al. Stroke. 2002;33:497-501

Copyright © American Heart Association, Inc. All rights reserved.

� Exclusions: “hypothermia, pyrexia, anemia, acute respiratory infection, if they were cardiovascularly unstable, if they had a condition that could result in a preexisting restrictive respiratory deficit, if they were medically unwell, if they were receiving medication that would depress respiratory function”

Journal of Gerontology: 2000, Vol. 55A, No. 4, M239–M244

Hypoxemia� Present in majority of patients in

the first 48 hrs after stroke

� Supplemental oxygen should be provided to maintain oxygen saturation >94%.

� Supplemental oxygen is not recommended non-hypoxemic patients with acute ischemic stroke.

Ref: 1. & www.researchgate.net

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Simple oxygen options

Hypoxemia caveats� Treat & Identify cause

� ABC’s

� Physical Exam� Adventitial sounds

� Airway assessment

� Comorbid conditions� CHF, chronic lung disease, OSA

� Chest X-ray

� ABG� Hypoventilation – hypercapnia

Ref: Radiopaedia.org

Hypercapnia� Signs/symptoms

� Hypoxemia

� Decreased level of consciousness – Normal pts 75-80 mmHg PaCO2

� Hypoventilation – shallow or slow respirations

� Measurement

� ABG

� EtCO2 monitoring

� Transcutaneous CO2 – not typically available

Ref: UpToDate

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Hypercapnia� Treat underlying cause

� Airway obstruction

� Positioning

� Underlying lung disease – COPD, asthma, edema

� Sedatives

� Ventilatory assistance

� Noninvasive ventilation – BiLevel > CPAP

� Intubation & Mechanical Ventilation

Respiratory Support� Airway patency

� HOB elevation

� Oral or nasal airways

� Noninvasive ventilator

� Intubation

� Atelectasis

� Incentive spirometer

� Respiratory treatments

� EZPAP

Airway Management� Patient positioning

� HOB 15-30 degrees

� Head positioning

� Neutral to extension

� Impingement of pharyngeal tissue with flexion

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Anatomical measurements.

Mingshu Cai et al. J Appl Physiol 2016;120:758-765

©2016 by American Physiological Society

Upper Airway

aneskey.com/emergency-airway-management/

� Oropharyngeal airways

� Poor tolerance – gagging/vomiting

� Nasal airway (Trumpet)

� Tip should reach the angle of the mandible

� Excessive length may reach esophagus

� Epistaxis

Advanced Oxygenation/Ventilation� High Flow Nasal Cannula

� Noninvasive Ventilation – CPAP/BiPAP-BiLevel

� Intubation/Mechanical Ventilation

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High Flow Nasal Cannula� Eliminate anatomic dead space

� Reservoir of high FiO2 in nose

� Improve gas exchange, CPAP effect

� Reduce the work of breathing

� Up to 60 L/min or higher

Ref: ResMed.com

Noninvasive Ventilation� Positive airway pressure

� Nasal mask or Full Face mask

� Helmet

� Benefits

� Improves airway patency, alveolar ventilation, reduce work of breathing

� Risks

� Aspiration

� Inability to protect airway, difficult to clear secretions

� Headgear requirements

Noninvasive Ventilation

https://careforyou.com.hk & CaStar CPAP Hood

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Mechanical Ventilation� Indications

� Inability to maintain airway

� Oxygenation or ventilation failure not amenable to other therapies

� Benefits

� Secure airway, ability to clear secretions, improvement of oxygenation & ventilation, & reduced work of breathing

� Drawbacks

� Sedation requirements, risk of infections, reduced mobility

� Liberation

Altered Respiration

Ref: UpToDate

� Seen in 60% of stroke

� More in more severe stroke

� Poorer outcome noted with sustained hypocarbia

� Ondine’s Curse

� Posterior/Brainstem strokes

Cardiac Complications� Hypertension very common on presentation

� 15% >184 mmHg

� 77% >139 mmHg

� Regression during first few hours post stroke

� Troponin elevations – 15%

� Arrhythmias

� Tachycardia - Atrial fibrillation 11%

� Bradycardia - Atrial fibrillation 5%

Ref: 1.

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Presentation BPHigh & low pressure associated with increased early & late mortality.

Optimal presenting SBP

130 mmHg, > in HTN pts

High BP associated with HTN

Low BP associated with CHF & CAD

Ref: 4.

Managing BP in Acute Ischemic Stroke� Optimal Blood Pressure is To Be Determined…..

� Studies don’t indicate aggressive treatment is beneficial

� Treatment for SBP >220 mmHg or DBP >120 mmHg

� Must account for patient factors

� Etiology

� Comorbid conditions

� CHF

� CKD

� CAD

Ref: 1. 3.

BP with Subarachnoid Hemorrhage� INTERACT2

� goal of achieving a systolic blood-pressure level of less than 140 mm Hg within 1 hour after randomization and of maintaining this level for the next 7 days

� No overt change in death or major disability either + or -

� Improved functional outcomes on modified Rankin scale

N Engl J Med 2013; 368:2355-2365

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Thrombolytic BP� Prior to therapy

� SBP <185, DBP <110

� Post rtPA

� SBP <180, DPB < 105

� Elevated risk of ICH

Ref: 1.

Hypertensive Medications� Adrenergic Blockers – Heart rate reduction, reduced contractility, vasodilation

� Labetalol, Esmolol, Metoprolol� Risks – bradycardia, decompensation of CHF, COPD/asthma?

� Dihydropyridine Calcium Channel Blockers – Arterial vasodilation� Nicardipine & Clevidipine

� Risks - CAD

� ACE Inhibitor - Vasodilation� Enalaprilat

� Risks – renal insufficency

� Vasodilator – Arteriolar vasodilation� Hydralazine

� Risks - hypotension

� Nitrates – Venous & arteriolar vasodilation� Nitroprusside

� Risks – Cyanide toxicity

Hypertension – Long term therapy� Pre-stroke diagnosis or new onset HTN

� JNC 7 guidelines

� Resumption after 24 hours of home regimen

Ref: 1. & Hypertension. 2003;42:1206

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Hypotension� Typically secondary

� 2.5% SBP <100

� Poor outcome

� Causes

� Hypovolemia

� Cardiac – AMI, CHF

� Infection – Sepsis

� Medication induced

� Hypothyroid, adrenal crisis, …

� EKG

� Volume assessment

� Noninvasive measurement

� CVP has ~50% accuracy

� Echocardiogram

� Chest X - ray

Ref: 1.

Volume expansion� Crystalloid IVF

� LR or NS

� Colloid

� Plasma

� Albumin

� Starches

� Elevated risk of renal injury

� Studies generally suggest equivocal outcomes with Crystalloid solutions vs Colloid

Maintenance of hydration� Daily fluid maintenance for adults about 30 mL/Kg/day

� 70kg patient – 2100 mL/day

� Isotonic fluid – 0.9% NaCl or Lactated Ringers

� Hypervolemia & Hypotonic fluid may increase edema

Ref: 1.

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Vasopressors� Norepinephrine

� Alpha 1 & Beta 1 � Vasoconstriction & mild increase in cardiac output

� Phenylephrine� Alpha 1� Vasoconstriction

� Dopamine� Beta 1 & Alpha 1 – dose dependent >5 mcg/min� Increase heart rate then vasoconstriction

� Epinephrine� Potent Beta 1, modest Beta 2 & Alpha 1� Increase cardiac output, heart rate then vasoconstriction

� Vasopressin� Antidiuretic hormone, used in conjunction with other vasopressors - vasoconstrictor

Ref: UpToDate

Diabetes Insipidus� 2 types – Nephrogenic & Central

� Central

� Deficient secretion of antidiuretic hormone (ADH)

� ADH causes resorption of water in kidney

� Signs

� Polyuria

� >3L/day - >125 mL/hr

� High-normal plasma sodium concentration

� Urine osmolality (<290 mOsm/kg) < plasma osmolality

� Urine specific gravity <1.005

Ref: Uptodate

https://basicmedicalkey.com/the-endocrine-system-7/

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Diabetes Insipidus� Water replacement

� Hypotonic IV fluids or free water

� NaCl 0.225% or 0.45%

� D5W

� >1L/hr must monitor glucose levels

� Glucosuria may exacerbate DI

� Desmopressin

� ADH analogue

� Vasopressin

� 5 units SQ q6hr

Ref: Uptodate

Fevers & Infections� 1/3 of stroke patients will become hyperthermic >37.6C

� Associated with worse outcome

� ASA/APAP beneficial if temp <38C

� Routine use of prophylactic antibiotics has not been shown to be beneficial.

Ref: 1. & 3.

Fever evaluation� Physical exam

� Lungs, skin, joints, heart, abdomen

� ETT, NGT, Foley, IV’s, EVD

� Surgical sites

� Diagnostic evaluation� CBC & Chemistries

� Blood cultures� Bacteremia – high risk, paucity of clinical findings

� Chest X-Ray

� Urinalysis

� Sputum

Ref: 3.

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Noninfectious fevers� Drug fever

� Acalculous cholecystitis

� Deep vein thrombosis/Pulmonary embolism

� Pancreatitis

� Transfusion reaction

� Ischemia

� Stroke

Glycemic management� Measure at onset or presentation

� Elevated in >40% of patients with acute ischemic stroke

� Hypoglycemia & hyperglycemia both may be detrimental

� Autonomic symptoms – typically <60mg/dL

� Diaphoresis, Tremor, Anxiety

� Altered mentation – typically <50mg/dL

� Confusion, altered speech

� Symptoms may result at higher levels in poorly controlled diabetes mellitus

Ref: 1., UpToDate

Glycemic management� Lack of good evidence for certain targets of glucose to show improved

outcomes

� American Diabetes Association recommendations

� Range of 140 to 180 mg/dL in all hospitalized patients

� Intensive glucose control - generally 80 to 130 mg/dL

� No difference in outcomes

� Higher rates of hypoglycemia

Ref: 1. & Cochrane Database Syst Rev. 2014

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Therapies� If NPO

� typically stop oral antiglycemics

� Limit Dextrose containing IVF� Maintenance fluids & intermittent infusions

� Typically insulin� Subcutaneous

� 1-4 units/50mg/dL elevation of blood glucose

� IV infusion

� Long acting insulin – NPH, detemir, glargine� 0.2-0.3 units/kg/day

Ref: UpToDate

Thromboembolic complications� High risk especially in first 3 months

� DVT - 10%

� PE - 3%

� Duplex of extremity venous system for DVT

� Inability to evaluate pelvic veins

� CT venography

� PE

� CT angiogram or V/Q scan

Ref: UpToDate

Thromboembolism Prophylaxis� Mechanical

� Pneumatic compression devices – SCD

� TED hose

� Chemical

� Heparin, Low Molecular Heparins

� Xa inhibitors – not studied

� IVC filter

� Only PE prophylaxis

Ref: UpToDate, Cook Medical

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Nutritional support� Catabolic state

� Prevent muscle loss

� Caloric deficit may be associated with increased mortality

� Swallow evaluation

� altered gag reflex, poor cough, dysphonia, incomplete mouth closure, elevated NIHSS score, or cranial nerve palsies

� Nursing evaluation & then Speech Therapist evaluation if needed

� Higher risk of aspiration & pneumonia with dysphagia

Ref: 1. & UpToDate

Nutritional support� Enteral route preferred

� Considered at 48-72 hours

� Variable outcomes in studies

� Early invitation may help with infectious complications & mortality

� Carbohydrate source with impaired fat metabolism

� Complications

� Misplacement

� Sinusitis

Ref: UpToDate

Nutritional support� Parenteral

� Early initiate is not associated with alterations in outcomes

� May have slight increased risk of infectious complications

� Secondary route – unable to give enteral nutrition

� Considered typically after 7 days for reasonably nourished patient

Ref: UpToDate

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Hypothermia� Associated with mild improvement in post cardiac arrest patients

� Moderate hypothermia 32°C–33°C

� Mild - 34°C–35°C may have fewer side effects

� Trials have been small & more pilot studies

� “There remains insufficient clinical evidence to establish a class of recommendation for induced hypothermia in acute stroke”

Ref: 1.

References1. Adams HP, et al. Guidelines for the management of patients with acute ischemic stroke: a

statement for healthcare professionals from a special writing group of the Stroke Council, AHA. Circulation. 1994; 90: 1588–1601

2. Torbey, M et al. Evidence-Based Guidelines for the Management of Large Hemispheric Infarction Neurocrit Care (2015) 22:146–164

3. UpToDate

4. Vemmos, K. N., et al. (2004), U-shaped relationship between mortality and admission blood pressure in patients with acute stroke. Journal of Internal Medicine, 255: 257–265.

Hypoxemia

� Etiologies

� Airway obstruction

� Hypoventilation

� Pulmonary parenchymal issues� Atelectasis, Aspiration, Infection

� Preexisting disease

� COPD, CHF & edema

� Thromboembolic disease

Ref: 1.