Pedi Nurse here! Right now I work at a clinic and we do plenty of straight caths in our pedi department. I just had a particularly stressful cath last week because the poor parents were balls of anxiety and I didn't have the best holding help at first (not my help's fault- it was her first time holding for a cath and the baby was crazy strong). So while it's fresh in my mind, here's my tips:
1. Start from the top and work your way down. When you're prepping the area with the betadine swabs, be focused towards the top of the pt's anatomy and look for where the betadine pools in the nook of the urethra.
2. When you're going in with the catheter, aim higher rather than lower. Sometimes, if you're just above the urethra, the lube will help the catheter slide right into the urethra. Working your way down the peri area, versus up, definitely reduces the chances of you winding up in the vagina. While it's not always a huge deal if you wind up in the vagina, if it's a little baby with a very intact hymen, there could be bleeding and some very angry parents to deal with.
3. Don't get too much lube on your catheter. Nothing's worse than trying to look through a big blob of goop at all the wonderful anatomy landmarks you just found while prepping with the betadine, or getting some of that goop on your "dirty" hand and then having it slide all over the pt's skin instead of holding the labia open. For that reason, I actually always make sure to add some sterile gauze to my prep table just in case I need to wipe off extra lube from the pt.
4. Make sure you're standing in the right position! If you're right handed like me, you should be standing next to the exam table so that you're leaning to your right to do the cath/ your left hand is the closest one to the patient. Standing the opposite way can make it a lot harder to see what you're doing and control the cath.
5. When you finally get the catheter in (woohoo!), you might feel some resistance from the baby as she cries/ scream and bears down. Wait until she pauses to breathe, then get that catheter in the rest of the way past those pesky sphincters! Don't rush it, don't force it- sometimes that's actually made my catheter fall right back out. Just wait for her to breathe.
6. I personally would never do a completely blind cath, again out of concern for hurting my patient. Make the best educated guess possible, aim high, but if after one or two tries you're getting nowhere just stop. The parents will definitely appreciate that you're not doing more than that to their child, and besides there's always bagging the baby for urine as a last resort.
7. Having really good holding help is always great too, but I know that's not always within your control. Luckliy I have lots of back-up to turn to for holding help, so if I'm with someone who just can't hold a kid down at all, I will stop, take my gloves off, and go get somebody else. There's no point risking injury to the patient because somebody else isn't doing what they're supposed to do (and it also makes the parents more anxious too, I think, to see poor holding technique).
8. As reassurance to my parents, I also make sure to let them know that any red, yellow, or orange in the baby's diaper is from the betadine and NOT from what I just did.
Hope this helps!