"He can't breathe." The former angel's voice was firm and urgent, but he took care to not sound panicked. Cas looked up from the older hunter, looking to Sam for direction in what to do next.
Sam let out a couple more curses, looking around him and then behind him out of the room. "Dean hold on-" He ran from the room, returning a second later with a canvas bag he had packed last night.
Dean's body bucked involuntarily as it struggled for air, and his eyes clamped shut with agony as the movement tore at his rib cage. Cas leaned forward, pressing down against his shoulder, helping to hold him firm against further movement without putting added stress on his injuries.
"Dean, one or both of your lungs collapsed." He tried desperately to ignore the widening of Dean's eyes. That look of shock that was too close to fear. He had been dreading this happening. With Deans rib injuries it was practically inevitable. The biggest risk factor after surgery, not breathing deeply enough.
Cas looked Sam directly in the eyes, trying to keep Sam focused and grounded. "How can I help?"
Sam blinked a few times. "Uh, keep doing what you're doing." Sam said, trying to refocus his efforts to get what he needed out of the bag. "Dean uh… I'm going to use this bag valve mask to breathe for you." In the hospital a team of doctors would have descended upon his brother. Nurses would push medications into his IV, and doctors would be shoving tubes down his throat. Machines could take over the function, let Dean sleep through the pain. Take over for his battered lungs for a bit. Here it was just him and Cas. Two people with no real medical training and no fancy machines to help.
Castiel tightened his grip on Dean.
Sam swallowed, looking up at the angel. "I'm going to use this bag valve mask… try to get his lungs working again." he repeated. He was strongly regretting never taking a proper CPR class to learn how to use one of these. He'd seen videos just hours before, but he'd never held one, and he fumbled with it, trying to reattach the mouth piece after he accidentally knocked it loose. Finally he was slipping it over Dean's mouth, slowly squeezing the bag.
Dean closed his eyes, relieved as at least some air made it into his lungs just as his vision was starting to tunnel. The relief was short lived as he became painfully aware that the only thing keeping him alive was this mask around his face in the hands of his brother.
"Shit… I left the tubes… Cas, you see what I'm doing?" Sam waited for a nod. "I need you to take over, I have to get the tubes, for the canister." Dean needed oxygen hooked up to this.
Cas slipped his braced arm out of the sling, shrugging it aside. He carefully stretched out to replace Sam's hand holding the mask around the older hunter's mouth and nose, using his good hand to take over compressing the rubber bag. Sam withdrew from the bed, hurrying back out of the room to gather supplies.
Dean reached up, hands reaching out without thinking, coming to hold Cas' stiffly wrapped arm. He held on as gently as he could make himself, still clinging like his life depended on it, and in some ways it did. He made eye contact with Cas, feeling slightly calmer when he saw the former angel's face set in concentration and not spiraling into panic.
Sam's hands were trembling, making it painfully slow to assemble the oxygen tank with the right hoses, and attach it to the mask. Twice he almost dropped the tank itself, but finally everything was running. He tried to calm his racing heart as he took control of the mask back from Cas.
The angel replaced his arm on Dean's shoulder, trying to offer some small grounding comfort.
Silence stretched between them as seconds turned to minutes. At some point Sam and Cas began taking turns, giving each a moment to smooth the cramps from their tired hands, getting ready to continue, just hoping that at some point Dean's lungs allowed him to begin breathing on his own again.
Sam's mind was looping through possibilities of what they could possibly do if Dean didn't regain the ability to breathe any time soon. What the next step could look like… He was just considering going to grab his laptop to scour the internet for anything else they could try when Dean tapped at Cas' hands, gently lifting the mask from his face, taking a weak reedy breath on his own.
Tears pushed at the corners of the older hunter's eyes as he managed to maintain thin but steady breaths.
Sam began hastily switching the oxygen to a simple over the mouth mask, looping it over his brother's bandaged head and letting it settle in place. It would do for now. He let himself relax slightly, his shaking legs turning to jello as the adrenaline began to leave his system.
"What-" Dean croaked out, muffled through the oxygen mask. He coughed gently, unable to finish.
"When you can't take deep breaths after surgery the lungs can collapse." Sam said softly, his voice betraying the small wobble of emotion. "The hospital probably would have put you on a ventilator before this could happen."
Dean reached up and squeezed his arm to say "you did it anyway" without speaking. He raised his other arm, letting his hand rest over Cas', still on his shoulder.
"Yeah." Sam relented. After a few minutes he leaned forward, burying his face in his hands.
Cas put a hand on his shoulder. "Sam, you should rest."
"I'm good."
"We should not leave Dean unmonitored through the night." Cas continued, completely ignoring the look of indignance the older hunter managed to throw at him. "I can stay with him now. You should rest so that you may take over watch."
Sam hesitated, but his tired brain couldn't find any fault with that logic. "Fine… just-"
"I'll call to you if I need help." Cas assured. Sam nodded in response, finally giving in and heading for the door.
Dean watched Cas' entire facade deflate the second Sam left the room. He was impressed by just how much Cas was keeping it together entirely for Sam's sanity. He reached up, finding the former angel's hand again and giving it a reassuring squeeze.
Cas looked sideways, giving a weak and exhausted smile. "Never do that again." He said, trying to break the tension a bit by quoting Dean from just a couple weeks ago when he had died by April's hands.
It had the desired effect, the hunter smiling from beneath the fogged plastic oxygen mask.
"When Sam informed me I should tell him if there was an issue with your breathing, I didn't anticipate something so…obvious."
"I never do anything halfway." Dean managed to whisper over the flow of air.
"No. I suppose you do not." Cas sighed, reaching out and catching Dean's wrist so he could take his pulse.
"Thank you." Dean rasped.
Cas nodded, still focusing on his heart rate. "Of course." He replied softly. He watched as Dean's eyes started to blink for longer and longer lengths of time. "You can sleep. I will be monitoring your rest."
"Told you Cas-" Dean mumbled, his words sounding half asleep already. " 's just creepy." He gave one last small smile before his face relaxed and he was asleep at last, the long day capped by that dramatic ending sapping the last of his strength.
Cas slid down the bed a bit to settle. He reached out his good hand, resting it against the side of the hunter's chest, feeling the steady rise and fall of his breath. It reassured him that Dean was still alive.
By the time Sam returned to take over watch, the Angel had drifted off, arm across Dean's chest, carefully attuned to his breathing even in sleep. Sam settled into the armchair in the corner, not bothering to wake them. He would let them get whatever rest they could.
Again, not TERRIBLY medically accurate, but dramatic!