Contending with Sedation Challenges

Effective sedation is usually a vital precursor to any successful endoscopic procedure. With the advanced techniques and medications available today, in the hands of a skilled provider, this component of the procedure can generally be dealt with safely, and in a highly efficient manner. Circumstances do arise, however, in which sedation can be difficult. Overcoming challenges in this respect can keep things running smoothly in the endoscopy suite.

“If patients are on narcotics at home, they can be difficult to sedate,” says Gail Spence, RN, BSN, staff nurse and rotation charge nurse in the endoscopy unit at the Hospital of the University of Pennsylvania. “Chronic pain medications, not necessarily narcotics, can make it more challenging as well.” Spence also notes patients who have recently had surgery and may have devices such as a patient-controlled analgesia (PCA) pump can be problematic in terms of sedation.

“If somebody’s a chronic pain patient and on narcotics, as you treat them it may be wiser to stick with agents such as propofol, which acts in ways that are independent of narcotics,” says Marc Koch, MD, MBA, president and chief executive officer of Somnia, Inc. “They really cause a patient to be more deeply asleep using a whole different mechanism. What you want to avoid with chronic narcotic patients is a situation where someone who’s on narcotics doesn’t take them for 24 hours, and then they start having withdrawal when they come into the office. That’s my biggest concern. I’m less concerned about a patient who I know is on chronic narcotics, because I can advise them to take the narcotic either in a lesser or greater amount, and during the surgery I can give them additional narcotics to meet their daily requirements, if you will.” This example illustrates the need for a thorough preprocedure evaluation, particularly with regard to drug history, including any illicit, herbal, or prescribed medications. “In each of these cases there are anesthetic implications, and you need to ask those tough questions, when, at the judgment and discretion of the anesthesia provider, that makes the most sense.”

Spence notes that contending with patients on potentially problematic medications such as narcotics usually involves getting help from anesthesiologists at her facility. “We generally use Versed® and fentanyl, but they can push propofol, which tends to put them down a little faster and for a little longer than the Versed and fentanyl might, especially if they’re resistant,” she says. “If we think we can sedate with the Versed and fentanyl and they’re still a little too awake, we can use Benadryl® to help put them to sleep. We use Benadryl on a fairly routine basis. It helps them sleep a little bit faster if it’s used earlier in the procedure, and it tends to work better than if you wait until later in the procedure.”

Benadryl (diphenhydramine) has the ability to depress the central nervous system, which may provide a synergistic effect for sedating patients. One recent study sought to assess the efficacy of adding diphenhydramine hydrochloride as an adjunct to improve sedation and to decrease the amount of standard sedatives used during colonoscopy.¹ The prospective, randomized, double-blind, placebocontrolled study comprised 270 patients undergoing colonoscopy. Patients were randomized to receive either 50 mg of diphenhydramine or placebo, given intravenously three minutes before starting conscious sedation with intravenous midazolam and meperidine. Of the 270 patients, data were analyzed for 258 patients, with 130 patients in the diphenhydramine group and 128 patients in the placebo group. There was a 10.1 percent reduction in meperidine usage and a 13.7 percent reduction in midazolam usage in favor of the diphenhydramine group. Additionally, patient scores for overall sedation and pain level were better in the group that received diphenhydramine. The authors concluded that diphenhydramine given before initiation of standard sedation offers a significant benefit to conscious sedation for patients undergoing colonoscopy.

At Spence’s facility, Benadryl is sometimes added to the medication list if doctors are familiar with a patient and know it’s taken a lot to sedate them in the past. “When they get the initial versed and fentanyl orders, they may start with Benadryl in addition.”

The use of droperidol may also be an option for patients who are difficult to sedate in some circumstances. Droperidol is a tranquilizer with some sedative and antiemetic effects; use of droperidol alone for sedation is not recommended. The drug is rapidly absorbed, and the therapeutic effect commences in three minutes to 10 minutes. Peak effect of the drug is not achieved until 30 minutes or more after either intramuscular or intravenous administration, however. Sedative effects following a single injected dose typically last from two hours to four hours. The most common adverse effects are hypotension and tachycardia, which tend to be minor.²

A randomized, double-blind study of droperidol in patients at risk for difficult sedation undergoing therapeutic endoscopy found the drug to be a useful adjunct to usual conscious sedation procedures.³ In this case, 120 patients with regular ethanol, narcotic, or benzodiazepine usage, suspected sphincter of Oddi dysfunction, or a history of difficult sedation were randomized to receive either droperidol or placebo along with midazolam and meperidine for sedation prior to the procedure. Time to achieve sedation, interruptions due to under-sedation, medication dosages, recovery time, and subjective assessments of sedation were evaluated and measured. The droperidol group had significantly fewer procedure interruptions and less difficulty with sedation, and required less midazolam (23 percent) and meperidine (16 percent) than the placebo group. There were no significant differences in time to achieve sedation, incomplete procedures, procedure length, recovery room time, or complications. There were significantly higher observer ratings of the quality of sedation for patients who received droperidol.

Another study showed that use of droperidol with a conscious sedation regimen of midazolam and meperidine resulted in a 10 percent reduction in the time required to start the endoscopic procedure, and reductions in drug requirements (23 percent less midazolam and 15.6 percent less meperidine) were observed in the droperidol group.⁴ Blinded participants noted that sedation appeared to be clearly improved by the addition of droperidol. Overall ratings of sedation quality by the endoscopy staff were also higher in the droperidol group. Time for recovery and frequency of complications of sedation were not significantly different between the placebo and droperidol groups.

Droperidol, however, does have the potential to cause adverse cardiac events.⁵ For this reason, the American Society for Gastrointestinal Endoscopy (ASGE) recommends that its use should be limited to patients with anticipated intolerance of standard sedatives, or for procedures that are anticipated to be longer than usual.

The possibility of apnea is always a serious concern in terms of sedation and anesthesia as well. “Considerations for anesthesia remain true no matter what agents you’re using,” says Koch. When apnea may be probable, the anesthesia team can fine-tune which medications they use with an eye toward reversal. “For example, let’s say you’re dealing with someone who’s five feet and 300 pounds; based on their pulmonary compliance and their cardiac issues, etc., you’re concerned that they may have an adverse outcome if their anesthetic depth is too deep. You can conceivably use agents such as fentanyl, Demerol®, Valium®, and midazolam, all of which have reversal agents. That means you can give a medication such as flumazenil, otherwise known as Romazicon®, and those medications will reverse Valium and Valium-like medications. For narcotics, like fentanyl and Demerol, there’s a medication called Narcan® that can be used. Some of the newer agents that have a better outcome for patients, that patients and GI doctors are clamoring for, don’t have reversal agents, so it underscores the need to have the right providers on-site when these agents are given more than anything else. I don’t think it’s an issue of picking the right or wrong medications; I think it’s an issue of anesthesia skill set.”

Certain neurological or psychiatric issues may play into sedation as well. For example, Koch notes that a patient with Alzheimer’s might get disoriented more quickly, and they may have particular problems during the wake-up and induction phases of anesthesia. “For patients who have a condition involving paranoia or anxiety, many anesthetic agents would not necessarily exacerbate that or make it worse; however they may lead to disinhibition,” Koch continues. “If you’re giving medications to patients and they get disinhibited, their psychiatric condition can manifest itself more boldly than it might otherwise. The medications that you use to treat psychiatric illnesses can also have profound effects, so I think one of the issues we look at in terms of our anesthetic is how these medications can influence the anesthetic care of patients, and that should not be forgotten.”

Pediatric patients may also have inherent characteristics that can make sedation for endoscopy challenging. According to the ASGE, preparation for endoscopy in children requires attention to physiologic, emotional, and psychosocial issues for both the patient and his or her parent or guardian.⁶ Pediatric patients may experience increased anxiety due to things like IV placement and parent separation. One study showed that psychological preparation before endoscopy significantly reduced patient and parental anxiety about the procedure.⁷ The study theorized that preparation may allow for a reduction in sedative medications and thereby enhance procedural safety.

Oral, nasal, and rectal administration of benzodiazepines have each been described as useful means of pre-medicating pediatric patients before intravenous conscious sedation or anesthesia.⁸ In terms of the actual procedure, physiologic differences between pediatric and adult patients make the risks for potentially serious complications during sedation and analgesia quite different.⁹ Compared to adults, small and compliant pediatric airways yield much greater airflow resistance, which can be exacerbated by the addition of even small amounts of mucous or edema. Additionally, in children, the tongue fills the upper airway to a greater extent than in adults.

“It’s hard to get a good prep for pediatric patients, and as a result, procedures can take a whole lot longer,” Koch points out. “From an anesthesia point of view, it’s not uncommon for these patients to be intubated and under general anesthesia, because they frankly cannot tolerate the procedure and the anesthesia in any other way. Pediatric patients also may have specific pediatric-related aspiration issues, and the depth of anesthesia they sometimes must be at for the entire procedure is significantly deeper, especially in the beginning and the end, than it would be for an adult.”

General anesthesia is commonly employed for pediatric endoscopy, usually based upon age or anticipated patient intolerance for the procedure.¹⁰ Other indications for general anesthesia can include the complexity of the procedure, physician preference, any patient co-morbidities, or institutional guidelines.

Conscious sedation may also be an option for pediatric patients. One study investigated sedation in children using propofol alone or combined with fentanyl or midazolam.¹¹ Factors such as efficacy, drug-related adverse reactions or side effects, ease of operation for the endoscopist, and time to discharge from the post-anesthesia care unit were measured in 240 children from one to 12 years of age undergoing endoscopic procedures of the upper gastrointestinal tract. The patients were given oral midazolam for a pre-medication and were then randomly assigned to one of the three study groups: propofol alone (Group P), propofol with fentanyl (Group PF), or propofol with midazolam (Group PM). Adequacy of sedation and ease of procedure were evaluated by the endoscopist, who did not know which drugs were used. The number of patients requiring supplemental doses of propofol to permit safe completion of the procedure was 31 in Group P (39 percent), 14 in Group PM (18 percent), and 11 in Group PF (13 percent). A lower incidence of adverse events was observed in Group PM and in Group PF than in Group P. The authors concluded that propofol in combination with fentanyl or midazolam gives better sedation and ease of endoscopy than propofol alone.

ASGE recommends that an individual trained in pediatric monitoring and, minimally, basic pediatric life support, should be present for procedures involving pediatric patients, in addition to the endoscopist, for the entire duration of sedated procedures. The presence of someone trained in advanced life support skills is preferable. Due to the depth of sedation commonly required in these procedures and the frequency of progression to deep sedation, some centers have instituted multi-specialty pediatric sedation units, which allows intensivists, specialty nurses, or anesthetists to provide uniform and consistent sedation and monitoring.¹²

In terms of monitoring, ASGE states that pulse oximetry and hemodynamic monitoring should be routinely used during pediatric endoscopy. Routine oxygen administration and rhythm monitoring have also been advocated, since data suggest that a significant proportion of children develop oxygen desaturation and/or arrhythmias during conscious sedation for endoscopy.

When considering the questions that should be asked of patients before a procedure from an anesthesia prospective, Koch suggests referring to the American Society of Anesthesiologists’ (ASA’s) “Anesthesia & Me”© checklist.13

I: Immune system (deficiencies, hepatitis, immunizations) or inadequate clotting (excessive bleeding)?

E: Endocrine system disorders (such as diabetes or thyroid conditions)?

“It’s very important to underscore that during the pre-operative evaluation, those questions that are asked should really be at the discretion of the anesthesiologist or the CRNA (certified registered nurse anesthetist),” Koch explains. “There’s no one question that should always be asked, and there’s no need to ask every question for every patient. What should be asked, how it should be asked, and when it should be asked should really be left up to the discretion of the anesthesiologist or CRNA. These people have the schooling and expertise with anesthesia to really make the judgment calls.”

Koch concludes by noting that when a patient undergoes surgery, no matter how minor it is, the anesthetics involved must not be taken lightly. “There is minor surgery, but there’s no such thing as a minor anesthetic,” he says. “Any time you’re giving potent anesthetics that can cause you to slip into general anesthesia, or that may lead to cardiorespiratory depression, that’s not minor no matter how you look at it; that’s something that is very serious.”

For references, visit www.endonurse.com. 

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