science

Rearrest

Rearrest is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Rearrest rather than just read about it. In short: Rearrest (also known as refibrillation or recurrent ventricular fibrillation) is a phenomenon that involves the resumption of a lethal cardiac dysrhythmia after successful return of spontaneous circulation (ROSC) has been achieved during the course of resuscitation. Survival to hospital discharge rates are as low as 7% for cardiac arrest in general and although treatable, rearrest may worsen these survival chances.

Key takeaways

Rearrest belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Rearrest to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Rearrest from memory before moving on to harder problems.

Reference excerpt

Rearrest (also known as refibrillation or recurrent ventricular fibrillation) is a phenomenon that involves the resumption of a lethal cardiac dysrhythmia after successful return of spontaneous circulation (ROSC) has been achieved during the course of resuscitation. Survival to hospital discharge rates are as low as 7% for cardiac arrest in general and although treatable, rearrest may worsen these survival chances. Rearrest commonly occurs in the out-of-hospital setting under the treatment of health care providers.

Cause Rearrest, which may have a similar etiology to cardiac arrest, is characterized as a compromise in the electrical activity of the heart often due to an ischemic event. The post-arrest patient who has recently obtained pulses, is dependent on prehospital care providers for ventilation assistance, arrhythmia correction through medication and blood pressure monitoring. Therefore, insufficient care in any of these treatments may contribute to a rearrest event. The lethal arrhythmia may be either ventricular fibrillation, ventricular tachycardia or asystole. A strong suspect that may be a critical contributor to rearrest is the administration of chest compressions to the patient when the patient has already achieved a pulsatile rhythm. It is often difficult to determine the presence of a pulse in a cardiac arrest patient, thus chest compressions may be given by the unaware resuscitator and this added stress on the heart may contribute to a rearrest event.

Treatment Similar to cardiac arrest, rearrest is treated with cardiopulmonary resuscitation (CPR) and defibrillation using either a manual or automated defibrillator. The goal of treatment is to re-establish a self perfusing heart through correction of the electrical activity within the heart. CPR entails chest compressions along with rescue breaths, while defibrillation involves a biphasic shock across the chest with the purpose of restarting the electrical activity of the heart. Anti-arrythmic drugs are commonly given during the ROSC phase. These drugs may include lidocaine and amiodarone.

Prognosis Rearrest may reduce the likelihood of survival when compared to patients who have had just one episode of cardiac arrest. Overall resuscitation rates have been estimated to be about 34%, however survival to hospital discharge rates are as low as 7%. This phenomenon may be contributed to rearrest.

Epidemiology A recent study by Salcido et al. (2010) ascertained rearrest in all initial and rearrest rhythms treated by any level of Emergency Medical Service (EMS), finding a rearrest rate of 36% and a lower but not significantly different rate of survival to hospital discharge in cases with rearrest compared to those without rearrest.

Research Current research seeks to predict the event of rearrest after patients have already achieved ROSC. Biosignals, such as electrocardiogram (ECG), have the potential to predict the onset of rearrest and are currently being investigated to preemptively warn health care providers that rearrest could be imminent. A stronger pulse detector would also contribute to lowering the rate of rearrest. If the resuscitator could accurately know when the patient has achieved ROSC, there would be less instances of chest compressions being provided when a native pulse is present.

References

Illustrations

Worked examples

Example 1 — a first encounter with Rearrest

Start with the simplest possible case. Write down what Rearrest claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Rearrest before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Rearrest ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Rearrest

In research: Rearrest appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Rearrest in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Rearrest is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cardiac arrhythmia, so understanding it makes those chapters shorter.
In everyday life: Look for Rearrest outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Rearrest in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Rearrest means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Rearrest out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Rearrest in simple terms?

Why does Rearrest matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Rearrest?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Rearrest.