I would split possible EM procedures into several categories:
1) Procedures I commonly let students do. While I wouldn't expect a sub-I to know all the nuances or necessarily be completely profficient in these by the time the sub-I begins, I would expect them to have a significant amount of familiarity with them so that my teaching/supervision can focus on the finer points. If the student has never done one by the time they start their sub-I, I would be very surprised. If they were very bad at these (ie: required explanation of basic technique/concept, unable to satisfactorily perform the procedure in a straightforward situation, etc) I would be a little disappointed.
- Basic laceration repair
- Abscess incision and drainage
- Peripheral IV placement
- ABG collection and analysis
2) Procedures I sometimes let students do. These would be procedures that students may have had a chance to perform or at least observe before, but not necessarily. I would not expect a student to necessarily be familiar with the technique, but I would expect the student to have read up on the concept and be able to explain the technique, indications, and complications in broad strokes. In the right setting (appropriate patient, department isn't going to hell, student is making a good impression otherwise) I would let a student perform this procedure under close supervision. I would expect most of the teaching to focus on the bread and butter of the technique. If the student had the bread and butter technique down already and this allowed me to offer some advanced tips, I would be impressed.
- Lumbar puncture
- Joint dislocation reduction
- Paracentesis
- Arterial line placement
- IO placement
- Splinting
3) Procedures I rarely let students do. The stars would have to align just right for these. It would have to be the combination of a rock star student, well suited patient, my availability, generous junior residents who would not give me the evil eye for giving these to a med student, lack of nursing supervisors (ie: night shift). If the student knew the technique, indications, contraindications, and complications, I might let them try. If they did not, I would not judge them for it, but probably not let them try.
- Endotracheal intubation
- Central line placement
- Chest tube placement
4) Procedures I would not let any student perform under any circumstances. My expectation would be for students starting a sub-I to know that these procedures happen and why, but that's about it.
- Resuscitative thoracotomy
- Cricothyroidotomy
- Lateral canthotomy
- Transvenous pacing
- Any of the group 3 procedures on children
In general, I would require a student to have at least some grasp of technique, indications, contraindications, and complications of a procedure, and ideally have observed at least one before I let them perform one. Based on that, and the categories I outlined above, I would recommend familiarizing yourself with those aspects, starting with category 1, then working your way down to categories 2 and 3.
By the end of a sub-I my expectation would be that they would be able to describe the basic technique, indications, contraindications, and complications for all of these procedures.