Cardiac Arrest Timelines: Why Accurate Timestamps Matter

You’re treating a patient who has just gone into cardiac arrest.

Naturally, someone starts chest compressions immediately. I don’t need to convince a paramedic, nurse, physician, or other resuscitation professional that knowing when the arrest began and when CPR was initiated matters.

But what about everything that happens afterward?

When was the first rhythm check? When was the first epinephrine given? When did the patient become shockable? When was the airway established? When did the rhythm change? When was ROSC achieved?

Those times can become surprisingly difficult to reconstruct after the fact.

Not every cardiac arrest looks the same, either, especially when you factor in location and resources.

If you’re working in an emergency department with multiple nurses, physicians, respiratory therapy, anesthesia, and other staff at the bedside, a tremendous amount can happen in a very short period of time. There may be several people documenting simultaneously, and the hospital’s systems may provide multiple sources of timestamps.

But even then, cardiac arrests don’t always go according to plan.

Now imagine a different scenario.

You’re the first arriving paramedic at a witnessed cardiac arrest. The family watched the patient collapse five minutes ago, called 911, and started CPR.

Time matters immediately.

You get the defibrillator pads on and perform a rhythm check.

Asystole.

This isn’t going to be a two-minute resuscitation.

You begin ventilations while coaching the family through performing adequate CPR. As additional responders arrive, the team establishes IV access, begins medications, works on the airway and reassesses the rhythm repeatedly.

The ETCO₂ is 12.

An SGA is placed, but the airway fills with vomit. It needs to come out. The airway is cleared. An ETT is considered and eventually placed.

Then the rhythm changes.

VF.

A shock is delivered.

Another shock follows.

Amiodarone is given.

The rhythm subsequently becomes a wide-complex PEA.

The family has mentioned that the patient has significant kidney disease, raising concern for hyperkalemia. Calcium and ventolin are administered while resuscitation continues with ongoing rhythm changes.

Eventually, you get ROSC.

Now everyone has another job.

Vital signs. Hemodynamic support via vasopressors. 12-lead ECG. Secondary lines, and additional airway management. Communicating with family. Packaging. Extrication. Preparing the patient for transport.

And somewhere in all of that, you realize something:

You know exactly what happened. But do you know exactly when it happened?

The Problem With Reconstructing the Timeline

When you’re working alone or with limited resources, documenting every event in real time isn’t always realistic.

You can remember the important events.

You remember giving epinephrine.

You remember the rhythm changing.

You remember shocking the patient.

You remember giving calcium.

You remember roughly when you got ROSC.

But remembering what happened isn’t the same as remembering when it happened.

Maybe the monitor recorded the shocks. That’s helpful.

But now you’re trying to reconstruct the rest of the timeline from memory, medication packaging, monitor records, your partner’s recollection, and whatever documentation you managed to complete during the arrest.

Sometimes you can reconstruct it accurately if you had enough hands to have someone scribing and they didn’t miss anything.

Sometimes you can get fairly close after combing through the monitor data.

And sometimes you’re standing at the hospital trying to answer:

“How long was the downtime?”
“How many doses of epinephrine were given?”
“When was the first shock?”
“When did the patient become PEA and what was the ETCO2?”
“When was the airway secured?”
“How long until the patient was receiving effective ventilation?”

And you’re realizing that you’re estimating.

That’s not ideal.

The Timeline Doesn’t Stop Mattering When ROSC Happens

It’s easy to think that once the patient arrives at the hospital, the problem is someone else’s.

It’s not.

The Paramedics may be the only people who witnessed the beginning of the arrest and the only people who were present for the entire prehospital resuscitation.

The emergency department and ICU teams inherit the patient and the story of what happened before they arrived.

Accurate timing can help them understand that story.

It’s useful for clinical handoff. It’s useful for retrospective review. It’s useful for quality improvement and documentation.

And ultimately, it’s part of the patient’s record.

Knowing what happened is important, but knowing when it happened can be just as important.

What If You Were Able to Simply Mark the Events as They Happened?

This was the problem I wanted to solve. There’s plenty of methods out there. Pen and paper, monitor timestamps, or bringing in the laptop. Almost always, multiple events are left out, or the person logging becomes distracted with other tasks. The pen goes missing, the pad of paper gets soaked.

I’ve been in these situations where, after the fact, reconstructing the timeline felt like trying to solve a crime scene.

You always knew what had happened, I just couldn’t always remember exactly when.

I didn’t like guessing and I didn’t like spending time trying to make the timeline fit together afterward. If you did have someone logging times - great - but sometimes you ended up with multiple pieces of paper, from different people, with different times on their watches, combining with a monitor with a different time. What a headache.

CodeMark: A Timestamp Logger Built for the Moments When You Don’t Have Time to Document

CodeMark is designed around a simple idea:

Don’t try to remember the timeline later. Mark it when it happens.

Instead of pulling out a phone and typing with your gloves on, or trying to write notes during a resuscitation and losing your pen, or soaking your pad of paper, CodeMark puts the timeline on your wrist.

With a single tap, you can record important events at the exact moment they occur.

During a cardiac arrest, that can mean quickly recording events such as:

• Epinephrine (with built in timer)
• Rhythm changes
• Airway interventions
• Medications
• ETCO₂ values
• ROSC
• Other important events

When you have more time—or more hands available—additional information can be entered through the app’s menus.

The result is a chronological record of the resuscitation, with timestamps generated automatically.

And when you need that information later, the timeline is still on your wrist.

Your Report Shouldn’t Be a Memory Test

By the time you arrive at the hospital, you’ve already done the hard part.

You’ve managed the arrest, made decisions under pressure, and coordinated a team.

You’ve treated the patient.

You shouldn’t have to rely on your memory to reconstruct the timeline afterward, and if you’re working in a system like mine, you’re always pressed for time, especially on paperwork.

With CodeMark, the information is already there.

What happened? Look at the timeline.

When did it happen? Look at the timestamp.

Every report becomes less of a memory test and more of a reference to what actually happened.

That’s better for the clinician documenting the call, and ultimately, it’s better for the patient whose care depends on an accurate story being passed forward.