Patient Positioning, Preoperative Evaluation, Patient Selection for ERCP
It is wrong to assume that all patients for endoscopic retrograde cholangiopancreatography (ERCP) can be sedated for their procedure. Numerous factors make deep sedation problematic for some patients. For example, ERCP is commonly performed with the patient in the prone position, occasionally with the patient’s head away from the anesthesia provider.1,2 Many ERCP procedures are performed in patients with a history of substance abuse, and some have suggested that general anesthesia may be better tolerated (and safer) than moderate sedation.3
This position makes ventilatory support via mask or tracheal intubation very difficult should the need arise. Additionally, the difficulty of a shared airway between the anesthesiologist and the surgical operator has significant implications for the use of sedation and impacts on airway management.
Sedation must be titrated very carefully to maintain adequate spontaneous respiration, and this can be difficult in an obese patient in the prone position.2 ERCP entails the placement of the endoscope into the esophagus, which makes mask ventilation and intubation nearly impossible should ventilatory support become necessary, and precludes the use of the laryngeal mask airway (LMA) entirely.
Given the above considerations, it would seem prudent to utilize general anesthesia for any patient whose airway, body habitus, or need for profound sedation increase the likelihood of requiring ventilatory support under deep sedation.
ERCP procedures are often performed on patients with multiple medical problems. In fact, the use of an anesthesiologist or an anesthesia provider to manage the ERCP patient is often determined by the severity of the patient’s illness. In some practices, only the sickest patients are referred to the anesthesiologist for evaluation and management, and their coexisting diseases often will impact the choice of anesthetic technique for ERCP.
In general, recommendations for the preoperative evaluation of patients exist: "Clinicians administering sedation/analgesia should be familiar with sedation oriented aspects of the patient’s medical history and how these might alter the patient’s response to sedation/ analgesia.
- abnormalities of the major organ systems;
- previous adverse experience with sedation/analgesia as well as regional and general anesthesia;
- drug allergies, current medications, and potential drug interactions;
- time and nature of last oral intake;
- history of tobacco, alcohol, or substance use or abuse." (Practice Guidelines for Sedation and Analgesia by Non-Anesthesiologists, www.asahq.org)4
Additionally, all patients should be examined with particular attention to airway assessment. These assessments are recommended for all patients expected to undergo ERCP, whether moderate or deep sedation techniques are planned. Again, for all patients, the possibility exists that general anesthesia may be needed, and airway management and maintenance may be necessary.5
For some other patients, medical problems discourage the use of deep sedation for ERCP. For example, a patient with severe gastroesophageal reflux is a poor candidate for a long procedure with an unprotected airway, as this represents a significant risk. In these patients, it may be safer to provide general anesthesia with endotracheal intubation (and the protection from pulmonary aspiration that the cuffed endotracheal tube provides) rather than risk aspiration or compromised ventilation.
It can be argued that the more precise control of a patient’s homeostasis afforded by general anesthesia makes it a better choice in the severely debilitated patient. For instance, patients with significant pulmonary or cardiac disease may not tolerate the reduced ventilation and hypercarbia sometimes induced by deep sedation techniques.6
The option of utilizing general anesthesia with controlled ventilation for ERCP is important and should not be dismissed if the patient is to receive optimal treatment. Moreover, the potential for inadvertent oversedation cannot be ignored, and the capability of providing general anesthesia (or rescue from it) should be available to ensure patient safety.
Inevitably, the anesthetic choice for ERCP depends on whether the patient will require general anesthesia rather than deep sedation to perform the procedure safely. The ultimate goal should be maintaining the greatest flexibility of anesthetic technique with the highest level of patient safety. A reasonable approach to the patient for ERCP is to treat every patient as if they were going to have a general anesthetic. Practice guidelines for sedation/analgesia by nonanesthesiologists have been proposed by the ASA1 and have been officially endorsed by the governing board of the American Society for Gastrointestinal Endoscopy.5 The preoperative evaluation should be as rigorous as that which is utilized for patients undergoing general anesthesia, and the precautions taken regarding evaluation of coexisting disease should be the same.
For moderate sedation, deep sedation, or general anesthesia, the standards from the Joint Commission on Accreditation of Healthcare Organizations require that a pre-sedation or preanesthesia assessment be performed for each patient. Additional patient assessments should include: a preprocedural medical assessment; history of prior anesthetic complications (patient and family); airway exam; review of type, location, duration, and degree of painful stimulation of anticipated procedure; and a discussion of the patient’s expectations from the procedure.5
As discussed above, particular attention should be paid to the patient’s airway, because access to the airway will be limited once the procedure begins. Based upon the preoperative assessment of the patient, the decision then can be made concerning moderate or deep sedation vs. general anesthesia.
1. Rigg JD, Watt TC, Tweedle DE, et al. Oxygen saturation during endoscopic retrograde cholangiopancreatography: A comparison of two protocols of oxygen administration. Gut 1994; 35:408-411.
2. Harloff M, Weber J, Kohler B, et al. Importance of cardiocirculatory and pulmonary monitoring in endoscopic retrograde cholangiopancreatography (ERCP). Z Gastroenterol 1991; 29:387-391.
3. Etzkorn KP, Diab F, Brown RD, et al. Endoscopic retrograde cholangiopancreatography under general anesthesia: Indications and results. Gastrointest Endosc 1998; 47:363-367.
4. Joint Commission on Accreditation of Healthcare Organizations. Care of Patients (TX): Standards, Intent Statements, and Examples for Sedation and Anesthesia Care. Comprehensive Accreditation Manual for Hospitals (CAMH): The Official Handbook. Oakbrook Terrace, IL: Joint Commission Resources; August 2000.
5. Wong RC. The menu of endoscopic sedation: All-you-can-eat, combination set, a la carte, alternative cuisine, or go hungry. Gastrointest Endosc 2001; 54:122-126.
6. Iber FL, Sutberry M, Gupta R, et al. Evaluation of complications during and after conscious sedation for endoscopy using pulse oximetry. Gastrointest Endosc 1993; 39:620-625.
After participating in this CME activity, the participant should be able to:
• identify the emergency medical equipment that should be immediately available when performing ERCP procedures;
• identify when airway assessment should be performed for ERCP patients;
• list the properties that make propofol an ideal agent for ERCP, and identify the settings in which it should be used;
• identify potential complications in the postoperative period.
1. When providing anesthesia for ERCP, the following emergency equipment should be available to ensure the patients’ safety:
A. a defibrillator, especially during deep sedation procedures
B. means of providing positive pressure ventilation and supplemental oxygen
C. means of suctioning the patient’s airway to prevent pulmonary aspiration
D. means of placing the patient in Trendelenburg position
E. all of the above
2. Airway assessment for all patients scheduled for ERCP should be performed:
A. to adequately anticipate potential difficulties in gaining access and/or managing the airway in an emergency
B. only in patients scheduled for ERCP under deep sedation technique
C. only if general anesthesia is planned
D. only if the patient describes a history of sleep apnea
E. to assess whether the use of laryngeal mask airway (LMA) is indicated
3. The use of propofol for ERCP:
A. is ideal because of its ease of titration and reversal
B. is ideal for deep sedation by nonanesthesiologists because of its short duration of action
C. is always used in combination with midazolam because of its lack of amnestic properties
D. is ideal because of its rapid recovery and anti-emetic properties
E. is ideal because unlike opioids, it has no effect on respiratory drive
4. Potential complications in the postoperative period include:
A. airway obstruction in patients whose intraoperative administration of midazolam for moderate sedation was reversed with flumazenil
B. agitation in patients who received ketamine intraoperatively
C. pressure necrosis in patients who underwent ERCP in the prone position
D. immediate oversedation upon entering the recovery room in patients who received moderate sedation
E. all of the above