This is a post about how we do most procedures in interventional radiology, with moderate sedation. This is part of the reason it can be quicker, less invasive, and more cost-effective to do certain procedures, like port placement in IR. For trainees and medical students, this is moderate sedation explained, so you can help convey this to patients. 

Some examples of procedures which can be done with moderate sedation include, but aren’t limited to: 

• Organ biopsies: lung, liver, kidney, salivary gland, etc.
• Ablations: lung, liver, kidney, capsular implant, etc. 
• Genitourinary intervention such as nephrostomy, nephroureteral stent placement
• Gastrointestinal intervention such as gastric tube placement
• Biliary intervention such as drainage, cholangioplasty, or stent placement
• Venous intervention such as recanalization, venoplasty, etc. 
• Arterial intervention such as embolization, recanalization, atherectomy, etc. 

Preparing the patient for moderate sedation: 

As a sedation nurse places an IV, he or she can begin to go over the basics of local anesthesia and moderate sedation. It helps to describe the process of injecting local anesthetic, its purpose, and how it will feel. An example I use is to say, “The local anesthetic will feel like a sting and a burn, and then that will go away. That will help to numb the area of access/ where we’re working.”

Some patients are more sensitive than others to the burning sensation associated with lidocaine. It helps to compare it to dental work, since that’s a familiar sensation many will have experienced before. But some patients have a hard time with this part, or are anxious, so it helps to have someone nearby, like a sedation nurse. They can encourage the patient to breathe through the discomfort, and remind them that the initial stinging sensation will be temporary. 

“Will you put me out? I need to be totally out.”

Patients utter these phrases often as I explain moderate sedation. Most patients assume procedures happen under general anesthesia. And sometimes, the referring office makes the mistake of telling the patient they’ll be “put to sleep.” So for the patient, consenting for sedation can be a rude awakening.

It helps to put a positive spin on moderate sedation, in my experience. I use phrases like “less invasive than anesthesia,” and “breathing on your own.” I explain that this kind of sedation relies on a combination of two strong drugs, used in small doses. This allows us to provide a safe level of sedation. We rely on a medicine geared toward pain, called fentanyl, and Versed (midazolam) for relaxation. 

When the patient protests, “But I can’t handle any pain,” I assure them the drugs we use are powerful. And if they jokingly encourage us to use a lot of them, I bring them on board with our approach by saying, “These drugs can decrease your drive to breathe, so we will use just the amount to keep you comfortable, while ensuring you can still breathe on your own.” A win-win, right? 

Amnesia

I warn patients that Versed can cause antegrade amnesia, so they may forget part or all of the procedure. We send them home with a responsible adult, and advise them not to sign any important documents that day. Some patients may know from past experience that they’re particularly sensitive to medications, and alert us before we get started.

For those patients, we can use a smaller dose, or no Versed at all, if the effects were disturbing to the patient. The amnestic affect is usually limited to 24 hours or less, although I’ve had some patients over the years report that the effect lasted up to twice that long for them. And despite the sedation on board, never say anything you might regret, or that might increase patient anxiety. The patient will be guaranteed to remember it!

“But I won’t feel anything?”

Everyone is different in this regard. Some patients sail through difficult procedures like a biliary drainage with hardly a peep. Others react to local anesthetic with a loud yelp, squirming or jumping on the table. So when people ask me if the procedure will hurt, I tell them it varies, and the initial stick is often the worst part. I assure them we will give them the amount of medicine tailored to what they need to feel comfortable while staying safe. 

Anxiety through the roof

Sometimes benadryl IV can be used to potentiate anxiolysis. 

Titrating sedation dose: 

A dedicated nurse or pair of nurses takes care to monitor the vital signs, ECG, patient responsiveness, and pain scale throughout a procedure. Patients who take narcotics or anxiolytics on a regular basis can usually tolerate (and may therefore need) higher doses of meds than patients who are naive to the drugs. This is part of the calculation of how many doses of analgesia (fentanyl) and anxiolysis (Versed) the patient can receive. 

Homeopathic moves

Sometimes just a bit of “social anesthesia,” or chatting with the nurse, can get a patient through the initial stages of a procedure. Sometimes, I lower the lights to make the room more relaxing for everyone. One of my techs plays classical piano on his phone, so it’s always emanating from under his lead. And for the sake of those wearing lead aprons and surgical gowns, we ensure the room is cool enough. This usually means lowering the temperature to the mid-60’s. Sweating under extra layers can make the procedure uncomfortable for the operators, and that doesn’t help anyone.

What if the usual sedation meds aren’t working? 

If the patient has chronic or severe pain, bringing out the big guns like Dilaudid (hydromorphone hydrochloride) can help to get the patient through a procedure. But I reserve this only for patients who have unrelenting pain despite the usual measures. 

It’s OK to bail out of a sedation case if the patient truly can’t tolerate it, provided it’s safe to stop at that particular point. You can alway re-schedule with anesthesia. Depending on your patient population, this only happens a few times per year, on average. Some patients are truly too anxious, or it’s just not their day. 

Overall, most patients leave pleasantly surprised that we were able to get their procedure done without anesthesia. Moderate sedation can be a quicker, less invasive way to get the job done, resulting in a quicker recovery. And for some patients who aren’t fit for anesthesia, moderate sedation may be their only option. 

For an overview of moderate sedation principles, see part one of this article in IR Quarterly. 

And for part two of the moderate sedation article, click here. Enjoy!