How to locate root canals in bleeding pulp chamber

Hyperemic pulps pose a challenge to the treating dentist at the first two stages of root canal treatment - anesthesia and access. While I have already discussed local anesthesia for acute irreversible pulpitis, locating root canal orifices with a bleeding pulp chamber requires extra time and attention of the dentist. 

• Know the proper access cavity preparation for the tooth you are treating. The proper shape and location of the access cavity will encompass all orifices of the root canals. Initially, there is no other way to know if you have uncovered the root canal orifice or no. 

Root Canal Access Cavity Preparations - Location and Shapes

• Flare the walls of the access cavity sufficiently. I find this to be the most helpful step. Flaring the walls of the access cavity helps in three ways. Firstly, it allows access to the root canals whose orifices have been uncovered. Many times, walls converging occlusally prevent the endodontic instrument from reaching the corner of the pulp chamber floor where the orifice is located. Secondly, it removes the bleeding pulp horns or attached tissue in the pulp chamber hindering our view. Thirdly, it facilitates removal of pulp stones which partially occlude the root canal orifice preventing complete pulp extirpation from the root canals.
• Extirpate pulp from the largest canal first using a broach. Locating the largest canal (distal for mandibular molars and palatal for maxillary molars) is the easiest with any endodontic instrument. The broach is the best instrument to be used here, how it should be used though, is debatable. While most endodontic texts recommend using the broach only up to the middle third of the canal to prevent instrument fracture, Richard Ten Cate in his dental histology text recommends using a broach apically as "The greatest concentration of collagen ....in the most apical portion of the pulp....affords a better opportunity to remove the tissue intact than does engaging the broach more coronally". In the clinical situation being discussed here, I take the broach as apically as I can because the broach is unlikely to bind and fracture in the straight and wide canals I am utilizing it for. 
• "You can never irrigate more". This advice from Dr. Stephen Cohen has stayed with me over the years and has proved immensely helpful. For those using sodium hypochlorite as the irrigant, it will help dissolve the pulp and aid more rapid and thorough debridement of the hyperemic root canal. For those using any other irrigant also, irrigation debrides the canal and provides a clearer field of view. The best time to peek into the pulp chamber to locate additional bleeding canals is immediately after irrigation of the located canals and pulp chamber. 
• Smaller root canals (mesial in mandibular molars and buccal in maxillary molars) can now be attempted using smaller files in their textbook locations. A #10 file best provides smallest tip with sufficient rigidity to canvass the pulp chamber floor without bending; but a #15 file usually suffices. 
• Extending the access cavity. If you have been unable to locate the bleeding root canals still, you might consider extending the access cavity minimally, and repeating flaring, irrigation and using smaller files.
• Thoroughly prepare the root canals found. Do not fret to locate all root canals before cleaning and shaping is begun. There is a subtle time when letting go precedes giving up. Determine the working length of the root canal(s) found, clean and shape them thoroughly and then re-attempt locating your other canals. If all else has failed, this is the road to success. You are in better control of the situation, there is no bleeding from the root canals prepared, you are better aware of the access cavity and you have given the hyperemic root canal more time for bleeding to arrest.
• Control the bleeding. A cotton pellet dipped in hypochlorite, local anesthetic solution containing epinephrine, a hemostatic agent or even normal saline may be tightly packed to the pulp chamber floor for a couple of minutes to arrest the bleeding and aid visualization. 
• Locating canals with rotary instruments. A rotary nickel titanium instrument with a non-cutting, fine tip but sufficient rigidity, such as Protaper S1 or SX (Dentsply Maillefer) also sometimes helps "catch" the root canal orifice when it eludes everything else. 

Additional Reading: Ingle's Endodontics 6. John I. Ingle, Leif K. Bakland, J. Craig Baumgartner. 6th ed. BC Decker Inc, 2008. (Pages 881-916)