This might help to add o2. Something almost any patient in distress needs.
Hydrogen Peroxide: As a (very) last resort you can add oxygen to the aquarium by dosing Hydrogen- Peroxide, which most people have in their first-aid cabinets. When Hydrogen-Peroxide (H2O2) mixes with water (H2O) it releases its extra oxygen molecule. The net result is added oxygen in the water. AS A GENERAL RULE: Adding 1 teaspoon (5ml) of 3% Hydrogen Peroxide for every 10 gallons of actual water in your tank, (tank capacity less decorations, equipment, gravel, etc.) will produce oxygen for an appropriately stocked tank for about 12 hours. This should be done by adding the H2O2 to a gallon or so of water scooped out of the tank, mixing same and then pouring the mixture into the tank from 6” or so above the tank. NOTE: THIS SHOULD ONLY BE DONE AS A LAST RESORT TO SAVE THE LIFE OF YOUR FISH. IT CARRIES WITH IT ITS OWN SET OF RISKS AND OVER-DOSING CAN BE TOXIC. THE EXACT DOSAGE TO BE USEFUL DEPENDS ON YOUR EXACT TANK, ITS VOLUME, HOW MANY FISH YOU HAVE, THEIR SIZE, ETC., ETC. MAKE SURE THE H2O2 IS 3% SOLUTION. IF IT’S 6%, USE HALF AS MUCH. 9%, ONE THIRD AS MUCH, ETC. BETTER TO START WITH A LESSOR DOSE AND OBSERVE THE FISH FOR SIGNS OF DISTRESS, BEFORE USING A FULL DOSE. (DISCLAIMER: WE ARE NOT RESPONSIBLE FOR ANY NEGATIVE AFFECTS THAT THE ABOVE REGIMEN MAY CAUSE.)