Shock States – Oren Zarif

Shock is a life-threatening condition characterized by global hypoperfusion of vital organs. It can lead to irreversible multiorgan dysfunction syndrome and death if not promptly recognized and treated.

Shock is often identified by stereotypic changes in well-known physiologic parameters, such as jugular venous distention, cool extremities and an elevated blood lactate level. However, physiologic reasoning is rarely applied in clinical practice.

Cardiogenic

Cardiogenic shock happens when your heart isn’t pumping enough blood to the lungs, depriving your body of oxygen. Most often, this happens because of a heart attack that damages the left ventricle, the main pumping chamber in your heart. However, it can also be caused by a blood clot blocking an artery in your lungs, severe pneumonia or progression of preexisting heart failure. It’s a life-threatening condition that’s usually fatal if it goes untreated.

Doctors diagnose CS by taking a blood pressure and doing chest X-rays. They’ll also order lab tests to see if your blood is pumped with enough oxygen and check for damage to major organs. You might need medicines to improve heart function and increase blood flow, such as vasodilators or inotropes. In addition, doctors might temporarily place a tube down your throat (intubation) to help you breathe. Some people with CS also need devices to assist the heart in pumping blood through the body, like balloon pumps and ventricular assists, or even surgery, such as coronary artery bypass, valvular repair or heart transplantation.

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If you have a severe case of cardiogenic shock, doctors may use the pulmonary capillary wedge pressure (PCWP) test to measure blood pressure in your lungs and determine whether your shock is caused by fluid overload or blood clots in the lungs. This is the only noninvasive test that accurately measures PCWP in cardiogenic shock.

During this test, a sensor is placed on your finger to measure systolic and diastolic blood pressure, and the device also takes an electrocardiogram, or EKG. The PCWP is then calculated based on these measurements. The results can be used to diagnose a variety of problems, including pericardial tamponade or massive pulmonary embolism, which are both common causes of cardiogenic shock.

Cardiogenic shock can be a serious and deadly condition, but it’s treatable. You can reduce your chances of developing the condition by making healthy lifestyle changes, such as eating a nutritious diet and getting regular exercise. You should also avoid smoking and breathing secondhand smoke. In addition, get medical treatment if you have warning signs of cardiogenic shock, such as a weak and rapid pulse and low blood pressure.

Rhythmic

Many different types of cardiac arrhythmia can occur, and most are short-lived and harmless. However, serious arrhythmias can disrupt heart function to the point of collapse and sudden cardiac arrest (SCA). Defibrillation is a treatment that uses paddle electrodes to deliver a shock to the patient’s chest which stops all electrical activity in the heart and allows the normal heart rhythm to resume. Defibrillation is used to treat both ventricular fibrillation and pulseless ventricular tachycardia, the most common forms of cardiac arrest in the prehospital setting.

Non-shockable arrhythmias may also cause cardiac arrest, but do not respond to a shock from the defibrillator. Non-shockable arrhythmias include ventricular tachycardia with a pulse and atrial flutter. Other arrhythmias such as atrial fibrillation and supraventricular tachycardia can be treated with cardioversion instead of defibrillation, which utilizes an electrical current that synchronizes with the heart’s important cycle in order to deliver the shock at the best time for the patient.

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The first step in resuscitating a victim of an out-of-hospital cardiac arrest (OHCA) with a shockable rhythm is to provide high quality chest compressions and bag-valve mask ventilations. Once the heart rhythm is resuscitated, it will be time to charge the defibrillator and begin treatment with it. The initial treatment of a shockable rhythm should be aimed at resetting the heart rhythm through the use of an external defibrillator, if available, and drugs such as lidocaine, amiodarone, and epinephrine in accordance with local protocols and American Heart Association guidelines.

If the victim of an OHCA is still in a shockable rhythm after several cycles of 30:2 compressions: breaths, or has a pulseless asystole, a shock should be delivered to the chest using the AED device. It is essential that the AED be able to detect a pulse, and if the underlying cause of the arrest is known, a drug such as atropine should be administered.

PEA/asystole and ventricular asystole are shockable rhythms that require immediate defibrillation, as they are considered to be life-threatening and untreatable by other means. The AED can be used to charge the defibrillator pads, and once a pulse is found the provider should pause the chest compressions and perform a rapid sequence of rhythm checks every 2 minutes until a normal rhythm is seen (this is called a “rhythm-based strategy”). Defibrillation in these cases is not intended to treat the cardiac arrest, but rather to shock the heart back into its normal rhythm.