Magnesium

mag

I rank Magnesium 18 out of the 33 drugs we carry.

I use magnesium very rarely. I used it once years ago for a patient in Torsades de Pointes with success. The call was an emergency transfer from the VA hospital to an acute care hospital. We arrived on the floor to find a breathless nurse telling us her patient had gone into cardiac arrest and she had performed two minutes of CPR before the patient opened her eyes and came back to life.

Yeah, right, I thought.

The patient was sitting up in bed reading a romance novel when we were introduced to her. A nice lady in her sixties who didn’t understand what the fuss was about. We chatted with her as we put her on our stretcher, and then just as we started wheeling her out the door, she passed out. I looked at the monitor – V-fib. I reached for the monitor and was gelling up the paddles when she opened her eyes and sat up. She was back in a sinus rhythm. I looked at the strip I’d recorded and saw the episode wasn’t v-fib, but the classic low amplitude/high amplitude/low amplitude of Torsades. In the ambulance, she went out again. I had just drawn up the magnesium when she revived. She wasn’t out but thirty seconds. I injected the magnesium into a small bag of saline and hooked her up to the drip, and she had no more episodes as long as she was with me, which admittedly wasn’t but another ten minutes.

A couple times I have used magnesium on cardiac arrests where the v-fib looked like it might be Torsades, but was likely just v-fib.

We can also use magnesium for eclamptic seizures. I have never had one of these calls, but I did fictionalize one in my novel:

Overbrook was in the Charter Oak public housing complex just a few blocks away from our location. Two story brick buildings built during World War II were laid out around several oval roads. The buildings looked in disrepair, the grass was burned. Shirtless children shouted and waved at us as we approached. Ahead we saw a parked police car and 463, its lights on and back door open.

The stretcher was outside the building in low position with the straps undone and the sheet spread out.
“They upstairs,” a young boy said. “Davey’s sister sick. She got the shakes.”

I followed Troy up the narrow staircase to the second floor. He took the steps three at a time, easy as walking.

We entered the apartment that smelled of rancid hamburger.

“Let them do their jobs!” I heard someone bark.

A man and woman were yelling at a police officer in the room at the end of the hall.

“Just take her to the hospital!” the man shouted.

“Calm down or I’m going to have to arrest you,” the officer said.

“That’s my daughter!” the man said.

“She’s sick! Lord, she’s sick!” the woman cried.

We pushed into the room. “Coming through,” Troy said.

A young woman lay on the bed convulsing, arms and legs jerking together. She had an oxygen mask on her face. She had to be two hundred twenty pounds. On the wall was a shelf of teddy bears and a poster from Disney’s Beauty and the Beast.

Andrew Melnick, a short, skinny paramedic, just twenty years old, was trying to tape an IV down on the woman’s jerking arm. Blood backed up in the IV line. Melnick’s hands shook.

“What do you have?” Troy asked.

“Lord, help my baby!” The woman cried.

“Take her to the hospital!” the man shouted. His breath reeked of alcohol. The police officer pushed him back. “Calm down or you’re out of the room.”

“Everyone quiet!” Troy said.

“She said she had belly pain,” Andrew said. “Then all of a sudden she started seizing. I just got a line and gave her five of Valium, but it’s not working.”

“Did you get a pressure before she started?”

“230/130.”

“Is she pregnant?”

“Pregnant? My daughter not pregnant,” the man said.

“She’s a good girl!” the mother shouted. “A church girl!”

“Take her to the hospital before she dies!”

“That’s it, you’re out of here.” The officer grabbed the man by the arm.

The IV line was knocked loose. Blood squirted in the air.

“Lee hold her shoulder,” Troy said. “Get some tape on that. Andrew get me an 18.” He knelt on the woman’s forearm to hold it steady and took the IV catheter Andrew handed him. “She’s got to be eclamptic.”

“But she said there was no chance.”

“Look at her pants. That’s not pee, she broke her water.”

Her sweat pants were soaked at the crotch. The smell wasn’t urine.

Troy had the IV in. “Give me some mag.”

Andrew fumbled with the one cc syringe as he tried to stick the needle into the small vial of magnesium I had handed him from the med kit. He pulled the plunger back. The drug drained into the chamber.

“Easy, my friend,” Troy said. “Get it in there and push it slow.”

Andrew again had trouble as he tried to stick the needle through the rubber port on the IV line.

“Easy,” Troy said. “That’s it. Now push slow.”

I felt a tension easing in the girl’s arms. The seizure stopped.

“Get your airway kit out,” Troy said.

The woman lay still. Her chest wasn’t moving. She wasn’t breathing.

“Bag her,” Troy said. He tossed me the ambu-bag as Andrew unzipped his airway kit and fumbled to get out the laryngoscope.

I applied the mask over her face, holding a tight seal around her mouth and bending her head back to keep her airway open as I squeezed the bag.

“How my daughter doing in there?” the man shouted.

The cop barred the doorway.

“Just fine,” Troy said to the man. “I’m shutting the door.” To us, “She still has a good pulse. Tube her.”
Andrew nudged me to the side and stuck the scope in her mouth and swept her tongue to the side, peering in looking for her vocal chords.

“She’s bradying down,” Troy said, “Get that tube in.”

“I can’t see the chords.”

Troy reached up and pressed on the front of the woman’s neck.

“I think I’m in,” Andrew said.

“You’re not,” Troy said. “I didn’t feel it pass.”

“Heart rate’s thirty,” I said.

“No, I’m in.”

“Pull it out,” Troy said.

Andrew attached the ambu bag to the end of the tube. Gave one squeeze. The bag didn’t reopen. I saw the belly rise. He pulled the bag off. Vomit surged out of the tube.

“Listen to me next time,” Troy said. “No, leave the tube there. Go in above it. Don’t go in so deep this time. She’s anterior.”

Troy handed him another tube. He went back in. More puke came out of the other tube.

Andrew’s partner turned his head. I could hear him vomit.

“Rate’s fifteen.”

Troy pressed his fingers against the neck again, just below the Adam’s apple. “That’s it. I felt it pass.”
Andrew attached the bag. This time you could see vapor in the tube. Good chest rise. Troy listened with his stethoscope while Andrew bagged. “Nothing in the belly. Good on the left. Nothing on the right. Pull back a little. That’s good. Solid placement. Tie it off. Yank the other tube.”

“Rate’s coming up,” I said.

But Troy wasn’t looking at the monitor. “We’ve got company.”

“What?”

Troy had pulled the woman’s sweat pants down. There between her legs was a bloody motionless baby.
“Throw me a blanket.”

I handed him a towel that was by the bedside.

Troy lifted the child and rubbed it with the towel. He brought the baby up to his mouth and gave it two breaths. He moved his fingers up and down on its chest. In between breaths, he told Andrew how to set up a magnesium drip, while Andrew’s partner bagged the woman through the tube.

“Drip set,” Troy said, “Hang it from the wall hanger. Lee get her on the board and strapped tight.” He gave the baby two more breaths. “Andrew get the infant ambu out, then get the OB kit and let’s get the chord cut.”

It was hot in that room, and I was sweating too, lifting and turning the woman to get the board under her and the straps around her fat. I was so busy I didn’t have time to stop and admire Troy, the calm he displayed. He kept us focused. At his direction I unhooked the woman from the monitor, and applied patches to the baby, who they laid on the short board on the dresser. Its color wasn’t quite as mottled. Troy had a tube in the baby’s mouth, and coached Andrew inserting a small catheter into the umbilical vein.

“Nice job,” he said to Andrew. “A little epi, a little atropine, and maybe things will be all right. You know the dose?”

“I have a field guide.” He reached for his side pocket.

“.01 per kilogram for the epi. .02 for the atropine,” Troy said. “Let’s make it .35 ccs for the epi and 1 cc for the atropine.”

The baby’s rate came up to 140. Troy stopped the compressions. Its color was close to pink now. “Attention all,” Troy announced. “In case you haven’t noticed. It’s a boy.”

***

The newest use for magnesium is as an IV drip in severe asthma. I have never used it (partialy because my old dog brain can never remember that we can do this now), but the few medics I know who have used it swear by it. I think if I had had this experience, I would likely list Magnesium higher.

***
Magnesium Sulfate

Class: Electrolyte

Action: Facilitates the proper function of many enzyme systems in the body
Facilitates the Na-K magnesium dependent ATPase pump
Blocks calcium non-selectively

Indication: Polymorphic ventricular tachycardia (Torsades de pointes)
Refractory or recurrent VF or pulseless VT if has documented
hypomagnesemia
Eclampsia
Severe Asthma

Contraindication: None for field emergency use

Precaution: Use with caution or not at all in the presence of renal insufficiency
or high degree AV block.

Side effect: Hypotension – mild but common
Heart block – uncommon
Muscular paralysis, CNS and respiratory depression – toxic effects

Dose: Torsades (pulseless)
– 2 grams over 1-2 minutes

Eclampsia
– 4 grams over IV drip over ½ hour if actively seizing
VF/VT (suspected hypomagnesemia)
– 2 grams IV bolus

Severe Asthma
– 2 grams in 100cc over 10 minutes IV infusion

VT/Torsades with a pulse
– 1- 2g slow IVP over 5 – 60 min

Route: IV drip or IV push

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