A Crash Course (3)
"...Six cans?" For a moment, I doubted my own ears. This twenty-year-old kid had guzzled down six cans of energy drinks or coffee in the dead of night just to study for an exam? Did he think his liver was indestructible? No, did he think his heart was? It was tachycardia, sure, but the cause was glaringly obvious: caffeine overload. I let out a silent sigh. The worst tragedies we encountered in the emergency room usually happened when the cause was unknown or completely out of our hands. At least in this case, the culprit was clear.
Right then, Baek Eunseo came running back, panting for breath. An intern followed close behind, wheeling an EKG machine. "Doctor! I have the EKG!" "Oh, okay. Good job." I patted Baek Eunseo on the shoulder. "Eunseo, let's move this patient to a bed in Zone A... actually, no, Zone B. Zone A is too precious for this. Lay him down in an empty bed in Zone B." "Start an IV line and give him one liter of fluids. Normal saline." "Ah, yes, sir!" Eunseo rushed off to guide the patient to a bed.
"Hey, kid." "Yes... Yes... Am I going to die? Is my heart going to explode?" "Right now, uh... it looks like this is happening because you drank way too many energy drinks. If you pump that much caffeine into your system, it'd be stranger if your heart didn't go crazy. It's only natural that it's beating at 160." The patient's face instantly flushed, shifting from sheer terror to embarrassment and confusion. "Ah... so... am I going to be okay?" "We'll have to monitor you to find out." I helped the patient lie down on the bed and walked back to the station.
I picked up the EKG strip the intern had printed out. Before I knew it, Baek Eunseo was sticking close to my side, staring intently at the paper with me. I tapped the paper with my pen. "Alright, take a look. What does it look like to you?" "It's sinus tachycardia." "Right, exactly. Sinus tachycardia." I let out a massive yawn and tossed the paper onto the desk.
I pulled back the curtain of Zone B where the patient was lying and approached him. "Well, first of all, there's no major issue with your heart. That means you don't have a sudden coronary artery blockage or myocardial necrosis. You can just think of it as your heart getting incredibly startled and throwing a bit of a tantrum." "Ah, I see..."
Baek Eunseo asked hesitantly, as if trying to cross-reference what she had learned from her textbooks. "Doctor, I have a question." "What is it?" "If the heart is beating so fast that the P-wave overlaps with the T-wave and becomes hard to see, making it difficult to differentiate between sinus tachycardia and PSVT... what's the best way to tell them apart? They're both narrow QRS tachycardias..."
Oh, that's a good question. Even through my exhaustion, I was slightly impressed. "Once the heart rate starts climbing past 150 or 160, the P-wave gets buried in the T-wave and disappears. Then you can't tell if it's sinus tachycardia with a buried P-wave, or PSVT where the P-wave is hidden somewhere weird from the start." "Yes! In that case, how do we..." "You just use adenosine." I pointed toward the crash cart.
"Ah! Not for therapeutic purposes, but..." Eunseo's eyes sparkled. "Exactly. For diagnostic purposes. It literally shuts down the AV node for a few seconds." I snapped my fingers.
"Say you push six milligrams of adenosine into a patient with ambiguous tachycardia. If the tachycardia stops and reverts to a normal sinus rhythm, then it's PSVT. The re-entry circuit passing through the AV node was broken by the adenosine. Diagnosis successful." "Wow..."
"Now, the second scenario. You push adenosine, but instead of a normal rhythm, a sawtooth pattern suddenly appears. Those are F-waves. That's atrial flutter. Since only the AV node is blocked, the atria's frantic beating is laid bare." "Scenario three: you push adenosine, and the heart rate slows down for just a brief moment before speeding right back up. But even during that brief slowdown, the P-wave is consistently attached right in front of the QRS complex. What is that then? That's sinus tachycardia." "Oh... adenosine..."
"But for this patient, the cause is obviously caffeine, and the diagnosis of sinus tachycardia is clear. For now, let's just pump him full of fluids and monitor his progress." Just then, the patient called out to us from the bed in a trembling voice. He seemed to have overheard our entire conversation. "Then, Doctor... can I be discharged right away...?"
Baek Eunseo and I turned to look at the patient at the same time. I stared at him blankly for a moment. "...No?" "What? But you said there's nothing majorly wrong with my heart. You said it's just... because of the energy drinks." "Yes. But that energy drink is still in your bloodstream, so where do you think you're going? Right now, your heart is running a full marathon." I rubbed my tired face with both hands. "Just get some sleep, kid. We'll discharge you much, much later."
"What? When?" "When do you think? When that number flashing on the monitor over there drops below 100 instead of sitting at 160. When your chest stops pounding, when you're not short of breath, and when you can walk around perfectly fine. That's when." I tapped Baek Eunseo on the shoulder. "Follow up with an EKG every thirty minutes. Once that one-liter bag of fluids is empty, hang another one." "Yes, sir! Understood!" Eunseo replied energetically. Her boundless enthusiasm felt somewhat foreign to me, prompting a small chuckle as I drew the curtain and prepared to head back to the station.
Just then, the patient lying on the bed called out to me urgently. "Doctor! Uh... Doctor." "Yes, kid. What is it?" "Can't... can't you just give me some medicine to make it better right away?" The patient still hadn't given up hope. I stopped and stared at him. His sheer determination to get out of here and do whatever he had planned, even in this state, was almost admirable. "Oh, are you a medical student? Pharmacy student? Or maybe nursing?" Otherwise, there was no way he would specifically ask for drug therapy in this situation.
"Ah... no. Nothing like that. I just... did a quick search online..." Ah, the internet. I let out a deep sigh and walked back to the bedside. "A search? What did you search? Something like 'heart palpitations emergency room'?" "Yes... well... treatments for when your heart beats fast, things like that..."
"Hmm." I crossed my arms. "Then what are you going to do if we discharge you right now?" "Pardon?" "If I send you home this very second, what are you going to do?" Failing to grasp the intent behind my sudden question, the patient glanced at his bag sitting at the foot of the bed. Through the half-open zipper, the corner of a thick prep book was visible. "...Uh, study...?"
A wry chuckle escaped my lips at his answer. This kid was really something else. I turned back to look at Baek Eunseo, who was standing behind me with an equally dumbfounded expression. "Well, Eunseo." "Yes, Doctor." "We can't let him go, right?" Eunseo caught on to my drift immediately and shook her head vigorously. "No. Absolutely not, Doctor."
I turned back to the patient. "See? Even the first-year resident says no." "But why... if you just give me some medicine..." "Kid, first of all, what you looked up was probably PSVT, but this is sinus tachycardia. They are completely different conditions." "What? How are they different..."
"Your heart actually wants to beat normally, but caffeine has traveled down from your brain and is whipping your heart, telling it to run without rest. That's what sinus tachycardia is." "Ah..." "So, that magic injection you read about? It probably won't do much of anything here." "Ah... I see..." The patient's face flushed a deep crimson from embarrassment.
I pulled up a chair next to the bed and sat down. "This is usually a case-by-case thing. Everyone's body is different." "Case-by-case...?" "Some people are born with a blessed constitution or bodies made of steel. They can chug ten cans of those energy drinks and be perfectly fine, just thinking, 'Huh, I'm having a bit of trouble sleeping.' I've actually seen guys like that." "But then there are people like you. Some get completely knocked out after just two cans and end up rushed to the ER. Their heart goes, 'Are you out of your mind, master?' and starts throwing a fit. Unfortunately, you have the latter type of constitution."
The patient's expression darkened. "Anyway, we need to flush this caffeine out of your system. These fluids we're pumping in will help your kidneys filter it out, meaning we have to flush it all out through your urine." I gestured with my chin toward the IV line in his arm. "So, this isn't something that's going to magically disappear with a single shot of medicine. We have to monitor you for a while until all those toxins leave your body. You need to rest, too. Don't you think?"
I glanced at the patient's monitor. 158 bpm. Still incredibly fast. "Ah... yes..." The patient finally hung his head, seemingly convinced. His dejected figure overlapped with memories of myself from a year ago. I asked on a whim, "It's only the beginning of March. The new semester has barely started, so what's the rush that has you pushing yourself like this in the middle of the night? At twenty, you should be busy having fun." "Ah, I'm... studying to retake the college entrance exam..."
Ah. A sudden silence fell over the space. I touched a sore spot. A re-taker. My voice softened slightly without me realizing it. "Studying is a marathon, not a hundred-meter dash. If you try to push through by drinking six cans at a time like this, your body will give out long before you even reach the June mock exams. You have to take care of your condition. Just because you stay awake and force-feed your brain doesn't mean it's actually going to absorb any of it." "Yes, Doctor..."
"Anyway, get some good rest. I'll check on you again once the fluids are fully administered. See that nurse call button over there? If your chest hurts more or if you feel shorter of breath, press it immediately. Got it?" "Yes, thank you..." I gave Baek Eunseo a nod and drew the curtain shut. As we walked back to the station, Eunseo suddenly gave me that look again—the one she reserved for her role model. Ah, the pressure. Maybe I should change the subject.
"Have you ever done something like that? Back in high school, during exam periods, I used to mix energy drinks with coffee in the middle of the night. When I drank that, I could literally hear my heart pounding in my ears. Looking back, it was pure madness..." I looked at Baek Eunseo, expecting her to relate. However, she just stared back at me with a completely blank, uncomprehending expression. "Ah, I always went to sleep right at ten o'clock!"
"..." I stared at her blankly for a moment. "...Until when?" "Until I graduated from medical school!" Eunseo puffed out her chest proudly, giving me a bright, innocent smile. "..." ...I think I got stuck with the wrong junior. Is she even human? She slept at ten? How is that even possible? Even during pre-med and med school? Even when studying for the licensing exam? What is she, an AI?