I'll be speaking on the basics of colonoscopy, I have no disclosures. I won't get into the technical aspects of the scope, John did a great job doing that on the upper endoscope, and the technical aspects are the same, with the exception that the colonoscope, whether it's a pediatric or adult, is slightly larger in diameter and has a slightly larger working channel, otherwise it really is the same, they are the same technical aspects. I will focus on pre-procedure, intra-procedure, and post-procedure variables. Even though you will not be performing the procedure, it is important that all of us understand the cognitive aspects of endoscopy. You'll be ordering the procedure, you'll have to explain it to the patient, and more importantly you'll have to interpret the results of the procedure, and any therapeutic aspects of the procedure, and make sure you accurately and effectively communicate those to patients in order to provide high-quality care. Some general comments, when we look at pre-procedure, we want to have timely scheduling, appropriate patient preparation and selection, we're performing a targeted HMP, not a whole consult in this particular instance, we need to assess bleeding risk and then an assessment for sedation, so let's take a closer look at some of these topics. Timely scheduling, I think that's pretty self-evident. Someone who presents with bleeding and weight loss is clearly more important from a scheduling and timely scheduling standpoint, as a carcinoma could be in the differential diagnosis, as opposed to someone who's had chronic diarrhea for six or eight months, so we should be smart about choosing who gets the procedure in a timely fashion. Patient selection, I think there are some important questions to ask ourselves. Anytime we order an invasive procedure, there are always risks, as you've seen through John's talk on upper endoscopy, so I always ask myself these important questions. If I'm going to perform a colonoscopy, will the results of that test change patient management? If patients have tried empiric therapy, has treatment failed, and would an endoscopy again change management? Is a therapeutic intervention anticipated? A patient had a screening colonoscopy at a smaller community hospital, a large polyp was found and now they're referred to me or one of my partners to remove this larger polyp, and as an alternative to a radiologic procedure. Some indications for colonoscopy, the most common ones we see now would be for screening colonoscopy, or for surveillance, remember screening is that first exam to look for polyps and continue exam to look for polyps if they did not have any on their first exam, or surveillance is a polyp or malignancy was found, and now we are looking out for the development of future polyps and hopefully not recurrent malignancy. Lower GI bleeding, whether that be rectal bleeding or hematochesia, blood in the stool, lower GI symptoms, abdominal pain, diarrhea, bloody diarrhea. Abnormal imaging, this is one we see a lot, we receive a lot of referrals for abnormal CAT scans, for thickening of the colon or lack of distensibility of the colon that can't be fully interpreted as a collapsed walls of the colon or thickening of the colon, so you'll see a number of referrals for abnormal imaging. Inflammatory bowel disease, whether we are making a new diagnosis based on symptoms or they are in a screening program for dysplasia, which is a change histologically that is the malignant change but not a full-blown malignancy, and are we performing a therapeutic intervention. Contraindication, it's important to know when we want to proceed with endoscopy and understand how to appropriately select patients, but it's equally important to know when we should not proceed or when we can cause harm. Anytime the risks outweigh the benefits. You get a referral for screening colonoscopy in a 75-year-old patient who's 100 pounds on two liters of O2 on anticoagulation and has heart disease, obviously that is not a patient we want to perform the screening colonoscopy on, the risks clearly outweigh the benefits. Unable to obtain consent for a non-urgent procedure. We must have consent in non-urgent procedures. In urgent procedures, when consent is not available, we can proceed if we deem it is a life-saving procedure in an emergent circumstance. If there is a known or suspected perforation, we should not proceed with colonoscopy. If there are acute changes or acute abnormalities in electrolytes, a potassium of 1.8, a low magnesium, a sodium of 120, a hemoglobin of 2.5, so any abnormalities that could put the patient at further risk if they have an endoscopic procedure and sedation at analgesia before those are corrected. And fulminant colitis. We would then run the risk of perforation, fulminant colitis, thickening of the colon wall, perhaps pneumatosis coli or air within the wall of the colon, and even microperforations. Pre-procedure patient preparation. Almost all of our patients are on clear liquids. Certain highly motivated patients can go on a low-residue diet. There are plenty of studies that show that patients who consume a low-residue diet the day prior to the procedure, their preps are outstanding, but you really need reliable patients who will stick to a low-residue diet. We need to understand the medications, and you've heard a nice talk on anticoagulants like dianperidine, so I won't comment further. John did a great job on informed consent. His principles that he discussed in informed consent for endoscopy also apply to colonoscopy. And bowel preparation is a separate lecture, but a very important part of the pre-procedure patient preparation. Just a brief comment on preparation. This is the Boston bowel prep scale. It's a very nice scale to use, and it's graded on a total of nine points, and you can see how each of the points are assigned for each of the colon segments, for each of the four – sorry, three colon segments, left colon, transverse colon, right colon, with three being the top and excellent and zero being poor. Very nice visual scale that can help us decide how the prep is. Sedation assessment. We've had a nice talk on sedation. Just a reminder, in the United States right now, the majority of sedation for procedures, specifically colonoscopy, upper endoscopy, is provided under monitored anesthesia care. It's at least 60%. For those who are doing moderate sedation, when you're explaining the procedure to your patients, make sure you understand how Versed and Fentanyl is used, understand the side effects. Moderate sedation is given typically with Fentanyl and Versed. People that should undergo deep sedation or perhaps even general anesthesia, those with difficult prior sedation, they've had previous procedures before, they've become combative, they couldn't tolerate the procedure. Those on chronic narcotics, benzodiazepine use, or a combination of the two, certainly would need monitored anesthesia care. Polypharmacy, narcotics, benzodiazepine, psychiatric medicines can be very, very hard to sedate. And in states where marijuana is legal, those who use marijuana chronically and at high levels, those patients can be very difficult to sedate. Those that are at increased risk for difficult airway management, so perhaps a short, stout neck, may be difficult to manage the airway, so that would be better addressed and managed by the anesthesia team. And those that are at increased risk for cardiopulmonary complications. Let's switch to interim procedure. The goal of the exam is to perform a high-quality exam. Some important markers, quality markers that we use to determine if a high-quality exam has been performed. Cecal intubation rate, current guidelines state that we should reach the cecum in greater than 95% of cases. In high-performing centers, it's typically 98.5% or higher. So we're looking for high levels of cecal intubation rate. Withdrawal times on a normal screening colonoscopy, minimum withdrawal time is nine minutes. So we want to see adequate withdrawal times, allowing us to visualize the mucosa adequately and perform a high-quality exam. I'll come back to adenoma detection rate and complications in a later slide. Intra-procedure, some things to think about when you're seeing the patient in a clinic. Understand that there are different types of scopes. There's an adult scope, there's a pediatric scope, and some units, mostly at academic and tertiary centers, they may have a slim scope, so a thinner diameter scope than pediatrics. Scope choice can be important. Some physicians prefer an adult or some endoscopists prefer an adult scope over a pediatric scope. So if you see that in a note or you know the physician you work with prefers those scopes, perhaps when ordering a colonoscopy, you may want to document that in a note. Body habitus could drive the scope we choose. Men with larger abdomens and perhaps larger abdominal fat may benefit from an adult scope, whereas thinner women who've undergone cholecystectomy, perhaps hysterectomy, or multiple abdominal surgeries may benefit from a pediatric scope where adhesions may be at play. So look at old records, look at the patient's body habitus to decide which scope is best for the patient you're seeing. Devices that we use are very similar in some ways to upper scope for upper endoscopy. Forceps, you saw those nicely exampled in the previous talk. We use snares a lot in colonoscopy. These are essentially small little lassos that are used to remove polyps. We use baskets and nets to capture polyps. We use injection needles to stop bleeding with epinephrine, to perform endoscopic mucosal resection, which is raising a polyp with a solution to minimize cautery effect and reduce immediate bleeding. We use injection needles to mark malignancies and mark large polyps to help us find those and to help guide the surgeons at the time of colon resection. We use hemostatic clips for bleeding and we use electrocautery for polyps. Forceps are used as tissue sample, most commonly to sample the colon to rule out perhaps microscopic colitis or to rule out dysplasia in inflammatory bowel disease surveillance. Polypectomy is typically done with either cold snare technique. That's where we are not using any cauterine. That is the most common type of polypectomy we perform, as opposed to a larger polyp, 10 millimeters or more, which we would more likely use cautery with our snare. As I mentioned, tattoo can be used to mark polyps and mark malignancies. Endoscopic hemostasis is achieved with a couple methods. APCs for arteriovenous malformations that are bleeding or not bleeding. Electrocautery can be used, whether that be a standard electrocauter unit or an ERBE unit, which uses a little different form of thermal therapy and hemostatic clips. Here's a picture of an adenomatous polyp being removed. If you look at the white device at the bottom right of the screen, that's the snare, and you'll see a little rim of white at the end of the snare, and that's the electrocautery being applied to perform a polypectomy. That's an arteriovenous malformation. The catheter you see coming out is for the argon plasma coagulator, which takes argon gas and converts it into a beam of energy, which allows us to ablate the AVM and minimizes tissue damage compared to a traditional laser, which was used in the past. Some other things you might see in reports that are performed in an intraprocedure. You might see dilation of strictures on colonoscopy. That's typically an anastomotic stricture in which we would use a balloon to dilate that stricture. You might see comments for a stent placement for people who have left-sided obstructing colon cancer. That could be used for palliative reasons or perhaps used as a bridge to surgery if chemotherapy or other forms of therapy are indicated. You might see the terms endoscopic mucosal resection, which is where a substance is injected to lift a larger polyp. The polyp is removed, and typically you'll see some type of marking material used for some type of changing of lights on our scope, which can be done. We typically work under white light, but there's something called narrow band imaging, which is a blue light, and some scopes also provide a third color red light to help us identify normal and abnormal tissue. And something you might see in the hospital notes, placement of a colonic decompression tube. Patient comes in with a colonic ileus. It's been determined that they need a colonic decompression, and you might see a tube placed or commented on in that note. Complications for colonoscopy. The risk of serious complications is low. Cardiopulmonary complications are the most common, and they tend to be simple. Hypoxia, hypotension, tachycardia, and sometimes bradycardia if a patient has a vasovagal episode when trying to push through a difficult segment of colon. We look at ways to reduce our risk of sedation complications. That's by identifying those patients who need more than moderate sedation, so we make an appropriate anesthesia risk assessment and determine when anesthesiology should be involved so we can have the appropriate monitoring, the appropriate airway management equipment available, and the clinical expertise of the anesthesia team. Some complications that we see. We see immediate post-polypectomy bleeding. So you remove a polyp. This is typically seen with either cold-snare polypectomy or hot-snare polypectomy. Bleeding persists beyond a few minutes. This is typically controlled with epinephrine injection, hemostatic clips, and less likely thermal therapy, so we can almost 100% of the times control immediate post-polypectomy bleeding pretty easily. Perforation is a dreaded complication and one none of us would prefer to see. It can be due to mechanical trauma due to the force of the scope that's being placed on the wall of the colon. Prior to the use of CO2, almost all endoscopy now is used with CO2, which is absorbed from the colon into the body, so we see less barotrauma, but barotrauma essentially is over-insufflation of the colon that could lead to a perforation at the cecum, and we can see electrocautory injury when performing polypectomy on large polyps that may lead to a perforation. So here's post-polypectomy bleeding. A polyp has been removed. The bleeding persists, and you can see a clip that's been placed at the bottom. It's not the best picture of the clip being placed, and that person is well on their way to having clipping done to stop post-polypectomy bleeding, and unfortunately, this is a site we prefer not to see. That is a perforation. We can attempt to close that defect with certain types of clips and advanced clips, but that is a lecture well beyond today, but that's a site none of us would prefer to see. You can see the normal colon wall outside of the yellow circle and inside of the circle. You can see into the abdominal cavity and likely the external surface or the serosal surface of another part of the bowel. Post-procedure, our job is to disseminate findings to the patients. So again, making sure we understand all aspects of the procedure so that when we explain the procedure, the results of the procedure, and any results of pathology, we come across as knowledgeable, caring, and provide high-quality care. We need to understand the medications that may be used in certain diseases, IBD, complicated medications to simple medications such as medications used for hemorrhoids. We need to transmit the pathology results and what they may mean for patients and what they may mean for surveillance program, specifically polyps. Post-procedure, we do have quality indicators that are important that all of our practices should be documenting. The currently accepted minimum adenoma detection rate for women is 20%, for men, 30%, for an overall adenoma detection rate minimum of 25%. High-performing groups, such as everyone I'm sure on this call, typically see a minimum adenoma detection rate of at least 40%. Sequel intubation rates, I said, again, higher than 95%. Post-polypectomy bleeding is about 1 in 500 to 1 in 1,000. And any time I remove a polyp, I make sure I tell that to the patient. And thankfully, colonic perforation from colonoscopy is very low. Some other post-procedure complications to consider, post-polypectomy bleeding, typically seen with cautery applied and less cold-snare polypectomy. Typical time frame is about five to seven days. That's typically when the S-scar or the scar formation falls off and an exposed vessel may bleed. Perforation, we typically know right away. There is some delayed, there is a risk of delayed perforation that can be seen with barotrauma. But again, that's a diminishing clinical scenario as we use more CO2 and less air to insufflate. Another one you may see is post-polypectomy syndrome. This is when cautery is used and there's injury to the bowel wall. We essentially have a transmural burn or burn through and through of the wall. Sometimes there's an area of focal peritonitis, but there is no perforation. So there's no perforation. The inflammation is contained. Patients present with fever, tenderness, and leukocytosis. The management is simple. IV fluids, antibiotics, and bowel rest. The goal is to prevent infection and to avoid a super infection and provide reassurance to the patient that they typically recover from this very quickly and will do very well. We'll finish up with a few pearls and some polling questions. It's important to think about the phases of colonoscopy. Sorry for the misspelling. We need to understand the cognitive aspect of the procedure so that we can effectively communicate with our patients and provide high quality care. Understand patient selection for our procedures. And equally important, understand when we should not proceed. Understand the complications from immediate complications to the post-polypectomy or post-procedure complications. And most importantly, any time you order a test or an invasive procedure in GI, whether that's upper endoscopy, colonoscopy, ERCP, ask yourself, will the procedure change the management and outcome of the procedure? Thank you. And we'll finish up with two quick poll questions. First question. Post-polypectomy bleeding when a polyp was removed with thermal therapy or corduroy is typically seen at 1 to 3 days, 2 to 4 days, 5 to 7 days. Excellent. Very good. Next question. Sorry, the correct question is 5 to 7 days. Next question, please. Current quality guidelines state minimum overall adenoma detection rate should be 10%, 15%, 20%, 25%. And this would be on a screening colonoscopy. There you go. All right, we have a bit of a split. But the correct answer, the minimum adenoma detection rate overall on a screening colonoscopy should be 25%. And in those units that are high quality units, you'll see numbers above 40% and even approaching 50%. Well, thank you again for allowing me to give this lecture. And I will now pass the baton back to Sarah.

colonoscopy

procedure

indications

contraindications

patient preparation

complications