CARDIOVASCULAR EMERGENCIES (Ventricular Tachycardia or Ventricular Fibrillation, Hypertensive Emergency and Cardiac Temponade)
VENTRICULAR TACHYCARDIA or Ventricular Fibrillation
- Conduct a primary ABCD survey (airway, breathing, circulation, differential diagnosis). Place airway device as soon as possible. Confirm placement, secure device, and confirm oxygenation and ventilation. Establish IV access, identify rhythm and administer drugs appropriate for rhythm and condition. Search for and treat identified reversible causes, with focus on basic CPR and early defibrillation.
- On arrival to an unwitnessed cardiac arrest or downtime longer than 4 minutes, five cycles (approximately 2 minutes) of CPR are to be initiated before evaluation or rhythm. If the cardiac arrest is witnessed or downtime is shorter than 4 minutes, one shock may be administered immediately if the patient is in ventricular fibrillation or pulseless ventricular tachycardia.
- If the patient is in ventricular fibrillation or pulseless ventricular tachycardia, shock the patient once using 200 J on biphasic (or equivalent monophasic, 360 J)
- Resume CPR immediately after attempted defibrillation, beginning with chest compressions. Rescuers should not interrupt chest compression to check circulation (e.g., evaluate rhythm or pulse) until five cycles or 2 minutes of CPR have been completed.
- If there is persistent or recurrent ventricular tachycardia or ventricular fibrillation despite several shocks and cycles of CPR, perform a secondary ABCD survey with a focus on more advanced assessments and pharmacologic therapy. Pharmacologic therapy should include epinephrine (1 mg IV push, repeated every 3 to 5 minutes) or vasopressin (a single dose of 40 U IV, one time only)
- Consider using antiarrhythmics for persistent or recurrent pulseless ventricular tachycardia or ventricular fibrillation. These include amiodarone, lidocaine, magnesium and procainamide.
- Resume CPR and attempts to defibrillate
HYPERTENSIVE EMERGENCY
A hypertensive emergency is an acute, severe elevation in blood pressure accompanied by end-organ compromise. In newly hypertensive patients, a hypertensive emergency is usually associated with a diastolic blood pressure higher than 120 mm Hg.
Etiology
- Essential hypertension
- Renal causes
- Renal artery stenosis
- Glomerulonephritis
- Vascular causes
- Vasculitis
- Hemolytic-uremic syndrome
- Thrombotic thrombocytopenia purpura
- Pregnancy-related causes
- Preeclampsia
- Eclampsia
- Pharmacologic causes
- Sympathomimetics
- Clonidine withdrawal, beta blocker withdrawal
- Cocaine
- Amphetamines
- Endocrine causes
- Cushing’s syndrome
- Pheochromocytoma
- Renin-secreting adenomas
- Thyrotoxicosis
- Neurologic causes
- Central nervous system trauma
- Intracranial mass
- Autoimmune cause
- Scleroderma renal crisis
Signs and Symptoms
Symptoms of end-organ involvement include:
- Headache
- Blurry vision
- Confusion
- Chest pain
- Shortness of breath
- Back pain (e.g. aortic dissection)
- If severe, seizures and altered consciousness
Treatment
- Nitroprusside
- Labetalol
- Fenoldopam
- Enalaprilat
CARDIAC TEMPONADE
Cardiac tamponade is pressure on the heart that occurs when blood or fluid builds up in the space between the heart muscle (myocardium) and the outer covering sac of the heart (pericardium)
Etiology
Cardiac tamponade can occur due to:
- Dissecting aortic aneurysm (thoracic)
- End-stage lung cancer
- Heart attack (acute MI)
- Heart surgery
- Pericarditis caused by bacteria or virus
- Wounds to the heart
Other possible causes include:
- Heart tumors
- Hypothyroidism
- Kidney failure
- Leukemia
- Placement of central lines
- Radiation therapy to the chest
- Recent invasive heart procedures
- Recent open heart surgery
- Systemic lupus erythematosus
Signs and Symptoms
- Anxiety, restlessness
- Chest pain (radiating to the neck, shoulder, back or abdomen), (sharp, stabbing), (worsened by deep breathing or coughing)
- Difficulty breathing
- Discomfort, sometimes relieved by sitting upright or leaning forward
- Fainting, light-headedness
- Pale, gray, or blue skin
- Palpitations
- Rapid breathing
- Swelling of the abdomen or other areas
Other symptoms that may occur with this disorder:
- Dizziness
- Drowsiness
- Weak or absent pulse
Diagnostic Evaluations
- Chest CT or MRI of chest
- Chest X-ray
- Coronary angiography
- ECG
Treatment
- The fluid around the heart must be drained as quickly as possible
- Pericardiocentesis is a procedure that uses a needle to remove fluid from the pericardial sac, the tissue that surrounds the heart
- A procedure to cut and remove part of the pericardium (surgical pericardiectomy or pericardial window) may also be done
- Fluids are given to maintain normal blood pressure until pericardiocentesis can be performed
- Medications that increase blood pressure may also help sustain the patient’s life until the fluid is drained
- The patient may be given oxygen. This reduces the workload on the heart by decreasing tissue demands for blood flow
- The cause of tamponade must be identified and treated
