Placing a central line is an ICU rite of passage. Some might even say it separates the mortals from the intensivists. But what happens when everything looks perfect—until it doesn’t?
In my two whirlwind years in the ICU, I’ve led codes, bathed in GI bleed carnage, and managed decompensating patients in rooms filled with beeping monitors and thinly veiled panic. But nothing—nothing—has consistently stressed me out more than procedures.
I’ll never forget my first central line. The patient was intubated, their internal jugular was practically screaming, “Poke me!” and I had spent hours obsessing over the Seldinger technique. I had watched so many videos that I could have taught a TED Talk on it. And yet, when I stepped up to the bedside, my hands trembled like I had just chugged six espressos. I tried to gown up solo (rookie mistake), and after five painfully awkward minutes of struggling, a nurse finally took pity and Velcroed me in like a toddler getting dressed for winter. Then, I meticulously checked—and rechecked—every piece of my kit, testing the retractable blade a good 30 times as if it would somehow grant me magical precision.
Fast forward 45 painstaking minutes—my first central line was in. Ultrasound looked good, blood was dark, the catheter advanced smoothly, and my patient remained blissfully unaware of my existential crisis. Still, I didn’t breathe until the chest X-ray came back confirming proper placement. Victory.
Since then, I’ve placed hundreds of central lines—during codes, on coagulopathic patients, in delirious screamers. But here’s the thing: I had never encountered a major complication. And if you’ve been in medicine long enough, you know what that means… “If you haven’t had a complication, you haven’t done enough procedures.”
Cue ominous foreshadowing.
One fateful night, I was placing a central line on a patient while a PA student shadowed me. It was a textbook case. Smooth insertion, no resistance threading the wire, and an ultrasound image so crisp it could have been in an academic journal. While waiting for the routine chest X-ray, I decided to turn this into a teaching moment. “How else can we confirm this is in a vein and not an artery?” We discussed the classic signs: dark blood, non-pulsatile flow, and of course, a venous blood gas.
I drew a sample, confidently handed it to the nurse, and we waited for the iStat verdict.
10… 9… 8…
And then: PaO₂ = 108.
Wait. What?! Cue full-blown panic mode.
The student, bless her innocent soul, asked, “Is that considered low?”
No. No, it is not.
My internal monologue:
This blood is dark.
The MAP is 90.
Nothing pulsated at me.
The patient isn’t even on high oxygen settings.
Why is the PaO₂ 108?!
Trying to suppress the rising terror, I called my attending. He responded exactly as I expected: “Hook it up to CVP.”
Surely, surely, it would show a venous waveform.
Except… it didn’t.
A venous tracing
An arterial tracing
The CVP waveform was unmistakably arterial.
At this point, the student looked at me with growing concern. “That’s normal for a vein, right?”
Oh, sweet summer child. No. No, it is not. Was This My First Big Complication?!
Sweating through my scrubs, I called a colleague at another hospital.
Me: “Hey, so… I think I just put a central line in an artery.”
Him: “Oof. You better call vascular.”
And that’s how I found myself leaving a sheepish voicemail for the on-call vascular surgeon at 3 AM. He called back and suggested attaching the line to an arterial line setup to get a blood pressure reading. If it was truly in an artery, we’d see a clear arterial BP.
Fifteen agonizing minutes later…
➡ BP reading: -2/-1.
Wait. What?! That’s venous.
Later, an echo revealed the patient had a patent foramen ovale (PFO)—a small hole between the left and right atria that can mix oxygenated and deoxygenated blood.
Translation? Their venous blood gas wasn’t actually venous. The vascular surgeon reviewed the evidence and confirmed the line was, in fact, correctly placed. A follow-up CT showed it terminating exactly where it should be—in the SVC. Cue the biggest sigh of relief in ICU history.
Key Takeaways: How to Confirm a Central Line
Signs You’re in a Vein:
Dark, deoxygenated blood
Non-pulsatile flow
Low resistance during placement
Ultrasound confirmation of wire in the vein
How to Double-Check Placement:
Chest X-ray – Standard first step
Blood gas from the line – Venous PaO₂ should be low (unless PFO shenanigans are involved)
CVP waveform – Should have a classic venous tracing
Arterial line setup – If in doubt, check for an arterial BP reading
Lessons Learned (AKA How to Avoid an ICU-Induced Heart Attack)
If a blood gas looks weird, check if the patient has a PFO before panicking.
If still unsure, consider hooking it up to an arterial line earlier rather than spiraling into a 3 AM crisis.
Even when you think you’ve seen everything, medicine will find a way to keep you humble.
So, in the end, my first major central line complication… wasn’t actually a complication at all. What actually won that title? Well, that’s a story for another day.