Abduction + Memory + Time + Fireworks + Dispersal thank goodness they didn't do seven seasons of this naming convention...
Okay folks, even though this aired quite a while ago I just now watched it, so I'm just now writing about it.
Awl - X-Ray + Penny - Duct Tape + Jack - CD + Hoagie Foil - Guts + Fuel + Hope - Wilderness + Training + Survival - Father + Bride + Betrayal - Lidar + Rogues + Duty - Nightmares - Seeds + Permafrost + Feather - Friends + Enemies + Border - Mason + Cable + Choices - Bitter Harvest - Kid + Plane + Cable + Truck - Tesla + Bell + Edison + Mac - Golden Lancehead + Venom + Pole Vault + Blood + Baggage
In conclusion to the nanotracker story arc, Mac and Riley go missing for over 24 hours. When they reappear, not only have they no memory of the previous day, but video footage shows them obeying dozens of commands, including one to fight each other and one to fire a weapon at a mannequin (though based on a line Mac says later, this horrifyingly might not have been the original version of this scene).
Vowing not to allow their bodies to be used against their will again, Mac and Riley decide to undergo a potentially dangerous treatment- exposing the nanites to high concentrations of oxygen in a hyperbaric chamber.
Just because mind control nanites are still pretty science fiction, this post will mostly be about hyperbaric medicine.
Hyperbaric Chambers:
Hyperbaric oxygen treatment is a type of treatment that uses high pressure and high oxygen concentrations to treat a variety of illnesses and injuries. These include things like non-healing wounds, crush injuries, carbon monoxide poisoning, cyanide poisoning, severe infections, and delayed radiation injuries.
A patient is placed into a chamber like the one above (though there are also larger chambers that can accommodate multiple people). Oxygen or medical air is then forced into the chamber, increasing the pressure to the prescribed depth. Depths vary depending on patient needs and the capabilities of the chamber, but can be anywhere from 1.4 atmospheres to over 6 atmospheres.
The high pressure and high oxygen concentration in the hyperbaric chamber allows oxygen to dissolve directly into the blood plasma. This helps higher concentrations of oxygen get to parts of the body that may not have the best circulation (non-healing wounds, crush injuries), give a boost of oxygen to parts of the body that need it (severe infections, delayed radiation injuries), or provide oxygen when the hemoglobin can't carry it (carbon monoxide poisoning, cyanide poisoning). The high pressure helps reduce the size of errant bubbles in the blood stream as well, which can treat the symptoms of air embolism and decompression sickness. The pressure is then gradually reduced to allow the bubbles to dissolve without severe pain.
Oxygen Toxicity:
In the episode, Mac and Riley require very high concentrations of oxygen in their blood in order to poison the nanites. Like any medical treatment, there are risks to hyperbaric oxygen therapy. Most of them have to do with air pockets in the body. These include barotrauma cause by bubbles under tooth fillings, in the sinus cavities, and the air in the inner ear which can expand and contract, causing pain. They can also include oxygen toxicity, which can be lung-related (burning pain, cough, difficulty breathing), or nervous system related (seizures).
In the episode, Mac suffers the latter type of complication when he has a seizure at 3.5 atmospheres. Seizures are a very rare complication (about 0.7 out of 10,000 treatments will result in a seizure), but oxygen toxicity does lower the seizure threshold. This means that for someone with a pre-existing seizure disorder or another reason they might have a seizure (low blood sugar, certain drugs, fever in children, etc...) they are more likely to have a seizure during a treatment.
Mac also was more likely to have oxygen toxicity than the typical person undergoing hyperbaric oxygen therapy. See, when a person is "at depth" in a chamber, they have a mask they can wear to give them room air (about 21% oxygen) at periodic intervals in order to prevent oxygen toxicity. Since the goal was to give Mac oxygen toxicity to kill the nanites, they likely forewent this precaution, which might have made it a lot more likely he would have had pulmonary complications or seizures.
The Bends:
Because he was in the chamber when he had the seizure, they decompress him and get him out of the chamber. It seems to take only seconds, even though they do hang a lantern on it by saying something to the effect of "we can't decompress him too quickly or he'll get the bends and then we'll never get him back!" (I'd quote it exactly but they took the episode off of Paramount+).
In reality, it would have taken at least an hour to adequately decompress him. If they needed to get him out as fast as they did, they'd need to re-compress him or he really would get the bends (though the bends is usually delayed by 15 minutes to 12 hours, so they'd have some time to get him back to depth). Here is a recommended re-compression table (18 MSW is the same as 1.8 atmospheres):
Has someone written that fic? Cause I need the fic where they have to break it to Mac that he has to go back into the chamber.
Anyway, this was a short one, but I hope you all learned something!
