Angiotensin II Cell Signaling - Physiological and Pathological Effects in the Cardiovascular System
Cardiovascular System II
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Transcript of Cardiovascular System II
Cardiovascular System II
Objectives• Present the clinical features and
emergency management of cardiovascular disorders, including:– Diagnose and treat rhythm disturbances.– Detect and treat cardiomyopathy.– Treat shock.– Create differential diagnosis and
management plan for syncope.
Case Study 1: “Not Breathing”
• 10-day-old boy brought to ED for not breathing and color change.
• 3 weeks premature, discharged from hospital 3 days ago with apnea monitor
• Decreased activity since discharge
• Poor feeding today
Initial Assessment (1 of 2)
PAT:– Abnormal appearance, abnormal
breathing, abnormal circulation
Vital signs:– HR 220, RR 14, BP 55/36, Wt 3.5 kg (birth
weight 3.7 kg), O2 sat 88% on room air
Initial Assessment (2 of 2)
A: Patent without evidence of obstruction
B: Nonlabored but diminished respiratory rate
C: Mottled, cool, distal cyanosis, tachycardic and weak pulse
D: Weak cry, nonfocal exam
E: Normothermic, no evidence of trauma, fontanel flat
Detailed Physical Exam
• Head/Neck: No abnormalities• Heart: Tachycardia, no murmurs heard• Lungs: Decreased breath sounds• Abdomen: Liver 2 finger breadths below
RCM• Neuro: Weak cry, lethargic, poor interaction,
responsive to pain and contact• Extremities: Cyanotic, cool upper and lower
extremities
Question
What is your general impression of this patient?
General Impression
• Cardiopulmonary failure– Lethargic but responsive, inadequate
respirations and tachycardia; mottling with distal cyanosis
What are your initial management priorities?
Management Priorities
• ABCs• Open airway. • Give 100% O2 by BMV, or perform
endotracheal intubation.• Check rhythm on cardiac monitor.• Obtain vascular access.• Obtain blood glucose prn.• Check rectal temperature.
Case Discussion (1 of 2)
• Tachyarrhythmias:– Wide complex
• Ventricular tachycardia• Supraventricular tachycardia (SVT) with
aberrancy
– Narrow complex• Sinus tachycardia• SVT
Case Discussion (2 of 2)
• Clinical features can be varied:– Palpitations in verbal children– Shock in any age– Generalized symptoms of malaise and weakness
• Diagnostic studies:– Cardiac monitor, ECG, sepsis evaluation if young
infant who has signs and symptoms suggestive of infection
– CXR, echocardiogram
• Management: ABCs, stabilize
Background: Dysrhythmias
• 3 basic types:– Fast pulse (tachyarrhythmia)– Slow pulse (bradyarrhythmia)– Absent pulse (pulseless)
• Dysrhythmias may impair cardiac function, leading to cardiac arrest.
• Occult dysrhythmias (e.g., prolonged QT syndrome, WPW syndrome)
Clinical Features: Your First Clue
• Intermittent, paroxysmal presence of symptoms
• Sudden onset of symptoms with little or no prodrome
• Presentation of dysrhythmias can range from stable to cardiopulmonary arrest.
Distinguishing SVT from STST SVT
History Fever, sepsis, dehydration, hemorrhage, hypovolemia, precedes
Intermittent, paroxysmal in onset
ECG ST rate is less than 2x normal rate for age. Rate varies with activity.
SVT rate at or greater than 2x normal rate for age. Minimal or no rate change with activity.
Supraventricular Tachycardia
Diagnostic Studies
• Radiology:– CXR important to look for signs of:
• Structural congenital heart disease• Congestive heart failure (prolonged dysrhythmia) • Signs of infection (pneumonia)
• Laboratory:– ALWAYS check blood glucose to exclude
hypoglycemia in any child with abnormal mental status.
Differential Diagnosis: What Else?
• Hypoglycemia
• Sepsis
• Hyperthyroidism
• Volume depletion
• Catastrophic illness:– CNS, GI, trauma (abuse)
• Metabolic disease
Management: Dysrhythmias• ABCs• Get baseline ECG.• Obtain vascular access.• For SVT (see AHA algorithm):
– Vagal maneuvers – Adenosine: 100 mcg/kg bolus, increase as necessary:
200 mcg/kg– Cardioversion for unstable SVT– Procainamide or amiodarone if QRS is wide– Digoxin to slow rate if cardioversion unsuccessful– Cardiology consultation
Tachycardia Management
The Bottom Line: Dysrhythmias
• Management is driven by presence or absence of poor perfusion.
• Sinus tachycardia is not an arrhythmia but its etiology must be determined.
• Provide ventilation and oxygenation for all patients in cardiopulmonary arrest, as the primary etiology is often respiratory failure.
Other Considerations (1 of 2)
• Interface with EMS/Transport:– Transport issues: Case such as this
should be transported to pediatric referral center after stabilization.
• ALS transport with monitoring and IV access• Treatment plan for possible en route for
recurrence – including potential for cardioversion
• Consult accepting pediatric cardiologist
Other Considerations (2 of 2)
• Documentation:– Always try to get baseline 12-lead ECG before
and after cardioversion.– Treatment record from prehospital and ED care– EMTALA compliance
• Risk management:– Always check blood glucose.– Assure rapid triage of infants in distress.– Do not hesitate to cardiovert when child is
unstable.
Reversible Non-Cardiac Causes of Dysrhythmias
• Four H’s:– Hypoxemia– Hypovolemia– Hypothermia– Hyper/Hypokalemia
and metabolic disorders
• Four T’s:– Tamponade
(cardiac)– Tension
pneumothorax– Toxins/poisons/
drugs– Thromboembolism
Case Progression/Outcome• ECG reveals SVT.• Infant receives BMV ventilation.• Preparations are made to cardiovert as IV
access is obtained.• Adenosine 100 mcg/kg IV push is given
followed by NS bolus (flush).• ECG shows return of sinus rhythm. • BMV is discontinued as infant’s condition
stabilized. 100% oxygen NRB mask is placed.
Case Study 2:“Unresponsive Episodes”
• 2-year-old girl passed out eating cereal; awoke after 5 min.
• She was stiff with eyes rolled back ~ approx. 5 min.
• Minimal period of sleepiness, now awake and alert; no retractions; skin color is normal
Initial Assessment and Focused History
PAT:– Normal appearance, normal breathing, normal
circulationABCDEs:
– Normal– Vital signs: HR 120; RR 24; BP 80/60; T 37.7 C Wt
12 kg; O2 sat 99%Focused History:
– Three similar episodes; two associated with “temper tantrums.”
– PMH and FH: Negative
Question
What is your general impression of this patient?
General Impression
• Stable– Patient with syncope – In no distress; normal exam– Concerning/ominous history
What are your initial management priorities?
Case Discussion
• Syncope in young children is a serious symptom.
• Must attempt to exclude life-threatening causes
• Differential diagnosis is critical:– Seizure– Cardiac – Breath-holding spell
Clinical Features: Your First Clue
• Loss of consciousness
• Lasted only a few minutes
• Minimal or no postictal state
• No stigmata of seizure: Urinary incontinence, bitten tongue, witnessed tonic-clonic activity
Diagnostic Studies
• Radiology:– CXR offers little.– CT or MRI may be indicated if considering
seizures.
• Laboratory is often normal but may include:– Electrolytes– CBC with differential
– Ca++, Mg++, PO4
Markedly Prolonged QT Interval
T-wave alternansT-wave alternans
Prolonged QT
• 10% present with seizures.
• 15% of patients with prolonged QTc die during their first episode of arrhythmia.– 30% of these deaths occur during the first
year of life.
What Else?Cardiac Causes of Syncope
• Hypertrophic cardiomyopathy– Syncope with exercise– At risk for sudden death; positive family history– Non-specific murmur; ECG can show non-
specific findings.– CXR is non-diagnostic– Echocardiogram is diagnostic.
• Chronic cardiomyopathy– Chronic CHF
• Dysrhythmias
Critical Concepts (1 of 2)
• Consider cardiac arrhythmias in all patients presenting with brief, nonspecific changes in level of consciousness: – Fainting, syncope, seizures, breath-
holding, apparent life-threatening events
Critical Concepts (2 of 2)
• Family history may be positive for sudden, unexplained deaths prior to 55, fainting episodes, or unexplained accidents.
• Episodes associated with exercise are particularly concerning. – Patient instructed not to exercise until
cleared by a cardiologist.
Pulseless Arrest*VF/VT Not VF/VT
Anti-arrhythmic
Vasopressor(Drug - Shock)
CPR x 3 min
Shock x 3
Shock
Vasopressor
*CPR and seek reversible causes throughout
Case Progression
• This patient has prolonged QT syndrome.
• She is at risk for fatal dysrhythmia (ventricular tachycardia or ventricular fibrillation).
• She needs to be admitted/transferred to a pediatric cardiology center for cardiology evaluation.
Case Outcome
• This child is hospitalized.• Monitored and confirmed to be at risk
for dangerous dysrhythmia• Discharged on medications shown to
decrease her risk of VT/VF (e.g., ß blockers)
• She is a candidate to receive an AICD when she gets older.
Case Study 3: “Chicken Pox”
• 6-month-old with chicken pox lesions that began 3 days ago. Lesions are spreading. More scabs today.
• Fever since yesterday, higher today.• Today, his skin appears to be red.• He is fussy and not feeding well.
Initial Assessment (1 of 2)
PAT:– Normal/abnormal appearance, normal
breathing, normal circulation
Vital signs:– HR 160, RR 40, BP 79/56, T 39°C, Wt 8.1
kg, O2 sat 98% on room air
Initial Assessment (2 of 2)
A: Patent without evidence of obstruction
B: Normal
C: Generalized red erythroderma, warm, tachycardic (febrile)
D: Nonfocal exam, irritable
E: Many impetiginous scabs, pustules and vesicles; some with surrounding cellulitis
Detailed Physical Exam
• Head/Neck: No abnormalities except for skin• Heart: Tachycardic, no murmurs heard• Lungs: Clear breath sounds• Abdomen: Normal except for skin • Neuro: Alert, subdued, no meningismus• Skin: Many vesicles, scabs, pustules; some
with surrounding cellulitis. Generalized warm erythroderma. Capillary refill 2 seconds.
Question
What is your general impression of this patient?
General Impression
• Compensated shock– Tachycardia and mild change in appearance
(fussy)– Possible septic shock as varicella lesions with
signs of secondary infection (Staph aureus, group A strep)
– Erythroderma: Scarlet fever versus toxic shock
What are your initial management priorities?
Management Priorities• Provide supplemental oxygen.• Obtain vascular access.• Determine rapid glucose.• Begin fluid resuscitation at 20 mL/kg – 160
mL NS.• CBC, blood culture, other optional labs• IV antibiotics• Repeated assessment for signs of shock
Shock
• Inadequate tissue perfusion (delivery of oxygen and nutrients) to meet the metabolic demands of the body.– Hypovolemic– Cardiogenic– Distributive– Septic
Background: Shock
• Compensated:– Vital organs continue to be perfused by
compensatory mechanisms.– Blood pressure is normal.
• Decompensated:– Compensatory mechanisms are overwhelmed
and inadequate.– Hypotension, high mortality risk
• Aggressive treatment of early shock:– Halts progression to decompensated shock
Clinical Features: Your First Clue
• Apnea, tachypnea, respiratory distress• Skin: Pale, cool, delayed capillary refill.
Warm shock will appear normal.• Lethargic, weak, orthostatic weakness• Tachycardia, hypotension• Specific types of shock:
– Neurologic deficits (spinal cord injury)– Urticaria, allergen trigger, wheezing– Petechiae, erythroderma
Hypovolemic Shock
• Fluid loss:– Diarrhea, vomiting, anorexia, diuresis– Hemorrhage
• Resuscitation:– Fluid replacement– NS or LR 20 mL/kg bolus infusions, reassess,
repeat as needed– Blood transfusion for excessive hemorrhage
Cardiogenic Shock
• Poor myocardial contractility or impaired ejection:– Cardiomyopathy, congenital heart disease,
myocarditis, tamponade, congestive heart failure, dysrhythmia, septic shock, drugs (e.g., thiopental)
• Resuscitation:– Fluid bolus (10 mL/kg) and reassess– Inotropes, pressors (e.g., dopamine, dobutamine,
epinephrine)
Distributive Shock
• Inappropriate vasodilation with maldistribution of blood flow:– Anaphylactic shock, spinal cord injury, septic
shock– “Warm shock”
• Resuscitation:– Vasoconstrictors (e.g., epinephrine)– Anaphylaxis treatment– Spinal cord injury treatment– Sepsis treatment
Septic Shock
• Elements of distributive shock and cardiogenic shock:– Inappropriate vasodilation with a maldistribution
of blood flow– Myocardial depression
• Resuscitation:– Fluid bolus– Pressors and inotropes– Antibiotics (expect possible deterioration initially
due to toxin release)
Case Progression/Outcome
• Labs drawn
• IV fluids given with decrease in HR to 120
• IV antibiotics given
• Patient admitted and discharged 4 days later
The Bottom Line: Shock
• Early recognition and treatment of compensated shock may prevent progression to decompensated shock.
• Decompensated shock has a poor prognosis.
EIF
• Available from ACEP, AAP
• Updated by PCP and specialists
• Very helpful• Medical ID
bracelet
The Bottom Line• Obtain rapid history and assess children
in shock or respiratory distress for cardiac disease.
• Utilize the EIF to gather information, contact specialists, and guide therapy.
• Echocardiography and cardiology consultation for definitive diagnosis and cardiac function determination.