"Using the constraints of the pouch size"
Aspirin:
For heart attack victims(Myocardial infarction), have them chew 1 tablet for about half a minute and then swallow it. Aspirin prevents blood clotting and can help a heart attack victim. Don't give aspirin if you are trying to control a bleed.
It is unlikely to do any harm if you are wrong.

Sweets:
For diabetics, if they are short of sugar it helps and if they have to much sugar it does no harm to them in first aid.
The sugar can be in candy, granular or liquid form. Syrups or juices are the safest because they are hard to choke on, but
restaurant size packages of granulated sugar or jams are convenient.
(Never even think about giving insulin because it could be lethal, especially if they are slipping into coma. If they have insulin, are concious and need it you may assist them but this is one thing that implied consent does not cover.)
A cheap small watch for timing their pulse and a small pencil+notebook for writing down the time when you checked their vital signs.
(you might want to know how they are changing over time, so you can tell if their condition is getting better or worse.)

Special items for yourself or other people in your party:
This depends upon the medical conditions of your traveling companions. For example a person with serious allergic responses might need an EpiPen.
Related to this are special items for location. You might want a suction cup type snakebite kit in the desert areas. They make pretty small versions of them now.

You might be able to fit a small magnifying glass for splinter hunting, a better set of tweezers and some small bandage scissors in that small bag too.