Cardiovascular Emergencies Chapter 18 Cardiovascular Emergencies

Case History You respond to a nursing home for a “heart attack.” On arrival, you find a 64-year-old female complaining of “crushing” chest pain and shortness of breath for the last 40 minutes. The patient tells you that she has had two heart attacks in the past and the pain is now similar.

Sudden Cardiac Death Heart disease is #1 cause of death in U.S. 340,000 prehospital deaths annually EMS cannot save all victims. The community is the “ultimate coronary care unit” for sudden death.

Ventricular Fibrillation Most common rhythm of sudden death Can only be treated with electric shock Early defibrillation is critical

AED and the Chain of Survival Early access Early CPR Early defibrillation Early ACLS

Role of EMT-B in Cardiovascular Emergencies Administer oxygen. Assist with the administration of nitroglycerin. Perform CPR. Provide early defibrillation. Request ALS assistance, as needed. Provide prompt transportation. Communicate assessment findings to hospital.

Review of Anatomy and Physiology

Chambers of the Heart and Conduction System

Systemic and Pulmonary Circulation

Cardiac Output Stroke volume  heart rate Either parameter can increase or decrease cardiac output. Varies with activity and other factors

Blood Pressure Measured in every patient > 3 years old Pressure exerted on the walls of arteries Cardiac output  resistance of vessels Contributing factors Force of contraction Heart rate Status of blood vessels (dilated vs. constricted) Blood volume

Inadequate Circulation – Shock Shock (hypoperfusion) Signs and symptoms Pale, cyanotic, cool clammy skin Rapid, weak pulse Rapid and shallow breathing Restlessness, anxiety, or mental dullness Nausea and vomiting

Arteriosclerosis Narrowing of the arteries Less blood can flow. Caused by buildup of fatty deposits and plaque Less blood can flow. First signs of disease may occur with physical exertion or stress.

Myocardial Oxygen Supply and Demand Normally oxygen supply via coronary arteries meets demand. Mismatch occurs when increased demand is not met by an increase in blood supply. May be due to narrowed coronary arteries Angina pectoris Problem can be addressed in two ways. Decrease demand (rest, nitroglycerin) Increase supply (oxygen, nitroglycerin)

Angina Pectoris Chest pain Commonly caused by increased oxygen demands on the heart Stress Exertion Exercise Relieved by rest and nitroglycerin

Myocardial Ischemia and Infarction State of decreased blood flow to tissues Myocardial ischemia Not enough blood flow to meet the oxygen needs of the myocardium Myocardial infarction Necrosis or death of heart cells

Ischemic Chest Pain Center of the chest May radiate to the neck, jaw, or arms Patients may complain of abdominal pain or indigestion.

Ischemic Heart Disease Signs and Symptoms Sudden onset of sweating Difficulty breathing (dyspnea) Anxiety, irritability Loss of consciousness

Cardiac Compromise Signs and Symptoms Feeling of impending doom Epigastric pain Nausea/vomiting Palpitations Lightheadedness Weakness Dizziness

Initial Assessment Identify need for priority care. Identify life-threatening conditions. Chest pain patient with altered mental status Consider impending cardiac arrest. Have CPR equipment and AED available. Patients with chest pain may prefer sitting position. Patients with altered mental status should be placed in supine position.

Initial Assessment Consider need for oxygen, airway, and ventilation. Nonrebreather Positive-pressure ventilation Check for signs of poor perfusion.

SAMPLE History Signs and symptoms Allergies Medications Past medical history Last oral intake Events surrounding the chief complaint

Important Questions Onset Provocation Quality Radiation Severity Time

Focused Physical Exam Patient may deny symptoms. Make every attempt to convince the patient to seek help. Altered mental status may be caused by low cardiac output. Examine neck veins and accessory muscles. Check breath sounds.

Baseline Vital Signs A range of vital signs are possible Normal vital signs Abnormal pulses related to arrhythmias Hypotension and other signs of hypoperfusion Cardiac arrest Preexisting medical conditions may alter vitals signs (e.g., hypertension)

Emergency Care of Responsive Cardiac Patient Perform the initial assessment. Ensure an open airway and consider the need for: Manual maneuvers (head tilt/chin lift, jaw thrust) An oropharyngeal or nasopharyngeal airway Suction

Emergency Care of Responsive Cardiac Patient Evaluate the adequacy of breathing and consider need for positive-pressure ventilation. Administer supplemental oxygen. Reduce activity and anxiety.

Emergency Care of Responsive Cardiac Patient Carry the patient to the ambulance in a position of comfort. Prioritize transport. Consider administration of nitroglycerin. Perform ongoing assessment en route to the hospital.

Nitroglycerin Generic name Nitroglycerin Trade name Nitrostat™

Indications and Contraindications Patient exhibits signs and symptoms of chest pain. Has physician prescribed sublingual tablets? Specific authorization by medical direction Contraindications Blood pressure < 100 mm Hg systolic Head injury Infants and children Patient has already met maximum prescribed dose.

Actions and Side Effects Relaxes blood vessels Decreases workload of heart Side effects Hypotension Headache Pulse rate changes

Nitroglycerin BP > 100 systolic BP < 100 systolic or no NTG Administer one dose. Repeat in 3-5 minutes, if no relief. Give up to a maximum of three doses. Reassess after each dose. BP < 100 systolic or no NTG Continue focused assessment. Transport promptly.

Administering Nitroglycerin Perform a focused assessment of the cardiac patient. Take blood pressure (must be >100 mm Hg). Question the patient regarding administration of the last dose.

Administering Nitroglycerin Ensure that patient understands the route of administration. Contact medical direction. Ensure right patient, right medication, right dose, right route. Ensure medication is not expired.

Administering Nitroglycerin Place tablet or spray under the tongue. Recheck blood pressure within 2 minutes. Record activity and times. Perform reassessment.

Reassessment Strategies Monitor blood pressure. Ask patient about effect on pain relief. Seek medical direction before readministering. Record reassessments.

Summary of Management of Patients with Chest Pain Place in the position of comfort. Administer oxygen. Assist with prescribed nitroglycerin. May be repeated every 3-5 minutes up to a total of three doses. If the systolic BP >100 mm Hg

Heart Failure Condition resulting from a damaged or weak heart muscle Caused by severe myocardial infarctions, chronic hypertension, and/or other causes

Heart Failure Left-sided Backup in lungs Pulmonary edema Dyspnea Accessory muscle use Rales on auscultation

Heart Failure Right-sided Backup in systemic circulation Swelling of body tissues Ankles, sacrum, abdomen

Cardiac Arrest Management Skills of the EMT-Basic One- and two-rescuer CPR Use of AED Request for ALS backup when appropriate Use of BVM or mouth-to-mask with oxygen attached Use of flow-restricted, oxygen-powered ventilatory devices

Cardiac Arrest Management Skills of the EMT-Basic Lifting and moving patients Suctioning airways Use of airway adjuncts Use of BSI History and physical assessment

Rationale for Early Defibrillation Ventricular fibrillation is the most common initial rhythm of cardiac arrest. Defibrillation is the only effective treatment of ventricular fibrillation. EMS systems have demonstrated increased survival through early defibrillation programs. Survival is associated with implementation of the chain of survival.

Time and AEDs Survival rate is approximately 50% after 5 minutes. Survival reduced by 7% to 10% each minute. Rapid defibrillation is key. CPR helps extend survival time.

Patient Age and Use of AED Medical patient >8 years old CPR AED with adult pads Medical patient 1-8 years old AED with pediatric pads Consider transport or ALS intercept

AED Analysis of Cardiac Rhythms Microprocessor confirms rhythms for which a shock is indicated. Accuracy is high. Analysis is dependent on properly charged defibrillator batteries. Inappropriate delivery of shocks Human error, mechanical error Ventricular tachycardia Attach defibrillator only to unresponsive, pulseless, nonbreathing patients.

Interruption of CPR Do not touch patient during analysis and shocks. Resume CPR immediately after every shock.

Advantages of AEDs Initial training and continuing education Speed of operation First shock can be delivered within 1 minute of arrival at the patient’s side. Remote defibrillation through adhesive pads Rhythm monitoring Option on some defibrillator models

If AED Advises No Shock Perform CPR for 5 cycles. If patient is awake and breathing adequately Give high-concentration oxygen. Transport. If patient is awake and not breathing adequately Artificially ventilate with high-concentration oxygen.

Standard Operational Procedures Defibrillation comes first when a collapse occurs in your presence. Do not do anything that delays analysis. EMT must be familiar with device.

Standard Operational Procedures Patient contact must be avoided during analysis. State “Clear the patient” before delivering shocks. Check batteries at beginning of shift. Carry extra batteries.

Recurrent Ventricular Fibrillation If patient wakes up after shocks: Check pulse frequently. If pulse is not present: Stop vehicle. Start CPR, if defibrillator is not immediately ready. Analyze rhythm. Deliver shock, if indicated. Continue resuscitation per protocol.

Conscious Patient Becomes Pulseless and Apneic Stop vehicle. Start CPR if defibrillator is not immediately ready. Attach AED, analyze rhythm. Deliver shock. Continue resuscitation per protocol.

No Shock Message Start or resume CPR. Analyze rhythm. After 5 cycles of CPR

Coordination with ALS Personnel EMS system design establishes protocols. AED usage does not require ALS on scene. ALS should be notified as soon as possible. Transport vs. await ALS per local protocols. Safety considerations Water – rain Metal

Postresuscitation Care Manage airway. Assess need for ventilation. Consider ALS backup. Keep AED attached to patient en route. Perform focused assessment and reassessment en route.

Defibrillator Maintenance Regular maintenance for defibrillators Daily operators shift checklist Defibrillator failure Improper device maintenance Battery failure Ensure proper battery maintenance and battery replacement schedules.

Medical Direction Medical direction is essential part of AED program. AED event must be reviewed by the medical director. Reviews of events Written report Review of voice-ECG tape recorders Solid-state memory modules Magnetic tape recordings stored in device Quality improvement

Cardiac Arrest Caused by heart rhythms that result in no blood flow Asystole Pulseless electrical activity Ventricular fibrillation/ventricular tachycardia Ventricular fibrillation is a useless quivering of the heart. Results in no blood flow Defibrillation is only effective treatment.

AED Computerized device that can recognize shockable vs. nonshockable heart rhythms Advises operator to deliver an electric shock when appropriate

AED Operation: 4 Steps 1. Turn on the device.

AED Operation: 4 Steps 2. Attach the electrode pads.

AED Operation: 4 Steps 3. Clear the patient and allow the device to analyze.

AED Operation: 4 Steps 4. When advised, clear the patient and push the shock button.

AED Electrode Pads Right pad Left pad Right upper chest Below the clavicle Right border of the sternum Left pad Left chest 2 to 3 inches below the armpit