© Springer International Publishing Switzerland 2017Basavana G. Goudra and Preet Mohinder Singh (eds.)Out of Operating Room Anesthesia10.1007/978-3-319-39150-2_9
9. Anesthesia for ERCP
Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, 330 Brookline Ave, Boston, MA 02215, USA
Rajiv R. Doshi
Anesthesia for endoscopic retrograde cholangiopancreatography (ERCP) continues to challenge even the most experienced anesthesiologist. The need for patient comfort and optimal procedural conditions has changed the anesthesia for these procedures from conscious sedation to deep sedation or even general anesthesia. The ongoing debate about deep sedation versus general anesthesia is dependent on a number of variables including severity of patient illness, availability of space and ancillary personnel, and positioning needs of the patient. A detailed discussion of the assessment and medical optimization of the patient, positioning of the patient, and utilization of anesthetic agents and airway adjuncts will aid the anesthesia provider to deliver a safe and comfortable anesthetic.
KeywordsERCPEndoscopic retrograde cholangiopancreatographyDeep sedationMonitored anesthesia careGeneral anesthesiaCapnographyPropofolProne positionAspirationObstructive sleep apnea
Endoscopic retrograde cholangiopancreatography (ERCP) is a complex and invasive endoscopic procedure requiring highly specialized equipment and instrumentation combined with live fluoroscopic imaging.
ERCP has been integral in the treatment of disorders of the pancreaticobiliary tree, sometimes supplanting to the need for surgical intervention.
While diagnostic ERCP has primarily been replaced with better noninvasive radiologic imaging, therapeutic ERCP indications continue to increase in number. Additionally, with better training and significant advances in technology, therapeutic procedures can be offered to patients that are sicker and with more complex anatomy. Patients with biliary sepsis present for urgent therapeutic ERCP to relieve obstructions and drain infected material.
The need for patient comfort while maximizing patient safety and optimizing procedural conditions for ERCP success has made anesthetic considerations critical to the success of these complex procedures.
Current indications for ERCP fall into three broad categories :
Stone disease (jaundice, biliary pain, cholangitis, biliary pancreatitis, pancreatic duct stones)
Ampullary/papillary abnormalities (Sphincter of Oddi dysfunction (SOD), ampullary cancer)
Biliary and pancreatic ductal abnormalities (leaks, strictures, malignancies)
It is important to discuss the unique space constraint issues and patient positioning issues prior to determining the suitability of delivering an anesthetic to a patient undergoing ERCP procedures.
Specific Procedural Issues Unique to ERCP Procedures
ERCP Procedure Room Layout
Most ERCP procedures in high volume centers are performed in dedicated fluoroscopic procedure rooms with a compact layout. Anesthesia providers are positioned at the patient’s head.
ERCP procedures in low-volume centers may be performed in a radiology suite or in the operating room using a portable C-arm fluoroscopy machine.
Rooms are compact but must accommodate the one or two endoscopists, a technician, 1–2 nurses, and an anesthesia provider. Additionally, the rooms have fixed radiographic equipment and video imaging equipment. Anesthesia personnel usually have an anesthesia machine as well as an anesthesia cart. ERCP equipment is stored in the procedure room; mobile units are rolled into procedure rooms that contain low-use equipment needed for procedures.
Space constraints with personnel and equipment need to be taken into account prior to administration of any anesthetic as removal of additional personnel or equipment may be required for further intervention.
Positioning for ERCP
ERCP can be performed in three positions: prone (most common), supine, and left lateral decubitus.
ERCP: Prone Position
This is the most common position for ERCP since it allows the endoscopist optimal visualization and access to anatomical structures.
Contraindications for prone position for ERCP include significant aspiration risk, advanced pregnancy, tense ascites, severe immobilizing cervical spine disease, and critically ill patients who cannot be turned prone due to lines/infusions/ongoing treatments. Patients who have marginal cardiopulmonary status are also not appropriate candidates for the prone position.
Prone positioning in conscious patients requires a cooperative patient who can lie on their abdomen for at least 5–10 min until adequate sedation is achieved.
Frail, elderly patients may have limited mobility and may require significant assistance to achieve the correct position. Additionally, arthritic changes in the cervical spine may make turning of the head difficult to facilitate passage of the endoscope. Pressure and skin injuries are also more common in frail elderly patients, so extra care must be taken in moving and positioning.
Post-cholecystectomy patients or patients with any intervention of the anterior abdomen (e.g. percutaneous transhepatic biliary drain) may require analgesia prior to positioning.
Anesthesia providers should ensure IV lines are not inadvertently displaced during movement and positioning. If analgesia or sedation is administered prior to movement, monitoring should be initiated prior to transfer. There should be minimal interruption of monitoring after assuming the prone position.
ERCP: Supine Position
Reserved for patients who are critically ill where position changes may lead to unacceptable changes in ventilation or cardiovascular status. Patients who are actively vomiting, known gastric outlet obstruction (physical or functional), and patients at high aspiration risk have their procedure performed in the supine position (e.g. active severe pancreatitis).
Patients with cervical spine disorders, altered airway anatomy, or patients at high risk for airway obstruction may benefit from the supine position.
Facilities performing general anesthesia for ERCP will often maintain their patients in the supine position to secure the airway.
Advanced pregnancy and patients with increased intra-abdominal pressure due to pathology (tumor, ascites) may benefit from the supine with left lateral tilt position to prevent aortocaval compression.
ERCP: Left Lateral Decubitus Position
This position is only possible in rooms where the fluoroscope can be rotated to obtain anterior-posterior views.
This is a potential alternative position for patients who cannot or will not assume the prone position.
Endoscopists may find this position less favorable in terms of visualizing the ampulla and cannulating the bile ducts. The literature does not seem to support this finding in deeply sedated patients .
Focused History and Physical Findings in Patients Presenting for ERCP
Prior to anesthesia consultation, the endoscopist has evaluated the patient and has deemed the patient a candidate for ERCP. The endoscopist needs to determine the case urgency based in patient’s clinical condition (semi-elective, urgent, emergent).
A complete and uninterrupted assessment of the patient should occur prior to administration of anesthesia by an appropriate anesthesia provider. Ideally, the person performing the anesthetic should perform the preanesthetic assessment.
The patient’s height and weight and body mass index should be obtained. Morbid obesity presents a multitude of management difficulties for both the anesthesia provider and the endoscopist.
Previous medication allergy history and specifically iodinated contrast allergy should be obtained.
A current list of medications should be obtained prior to initiation of the procedure. If patient is an inpatient, a current home medication list is also important. Many patients are on antiplatelet agents, direct thrombin inhibitors, or oral or intravenous anticoagulants that can lead to excessive bleeding with specific ERCP procedures.
Previous procedural/surgical history and issues with anesthesia should be obtained. Any history of difficult mask airway or intubation should be clarified and previous records should be obtained. This is especially true for patients with history of sleep apnea.
Patients with family members with anesthetic histories suggestive of malignant hyperthermia or prolonged neuromuscular blockade with succinylcholine should be identified.
The patient’s current cardiopulmonary status and current medical conditions should be obtained and documented.
Organ system dysfunction related to the hepatic or pancreaticobiliary systems should be fully characterized with imaging and appropriate laboratory values.
Patients with serious organ system dysfunction may have concomitant bleeding disorders. Patients on anticoagulants/antiplatelet drugs should be identified. If sphincterotomy or biopsy is planned, timely assessment of coagulation or platelet function should be conducted prior to such intervention.
Family history, social history and review of systems should be obtained. Patients with chronic opioid abuse or significant opioid use secondary to pain management should be identified, as there can be difficulty in sedating these patients appropriately.
Pathophysiologic Considerations (by Organ System) Prior to ERCP
A previous history of intestinal diversion surgery (e.g. Roux-en-Y gastric bypass or gastrojejunostomy) can potentially prolong an otherwise routine ERCP and necessitate alterations in the anesthetic plan. Tumor burden, especially if extending to the gastric outlet or within the abdomen increasing intra-abdominal pressure may place the patient at high risk for aspiration.
Significant liver dysfunction may increase the risk of variceal bleeding on insertion of the ERCP scope. Additionally, large-volume ascites without paracentesis significantly increases risk of aspiration due to increased intra-abdominal pressure.
Patients with uncontrolled hypertension or unexplained hypotension should be evaluated and treated prior to ERCP if possible. Adjustments to chronic cardiac medications may need to occur due to malabsorption and/or hypoalbuminemia from the current disease process.
Older patients undergoing ERCP may have a history of myocardial infarction with cardiac stents requiring potent antiplatelet agents that can cause significant bleeding during ERCP, particularly sphincterotomy. The most commonly used agents are clopidogrel, prasugrel, and ticagrelor. These agents should be discontinued only after direct interaction with a cardiology specialist; ERCP procedures can be performed without discontinuation but must be discussed in advanced with all team members.
Congestive heart failure can present acutely or as an acute exacerbation of a chronic condition. Acute decompensated heart failure should be treated aggressively prior to ERCP. Patients with significant oxygen requirements from chronic CHF may require general and mechanical ventilation.
Cardiac arrhythmias, particularly atrial fibrillation, usually require systemic anticoagulation. Discontinuation of anticoagulation must be done under the direction of the prescribing physician (outpatient) or medical service (inpatient). Bridging anticoagulation should be performed by the prescribing physician in consultation with the patient’s cardiologist. Laboratory values to ensure no residual anticoagulation should be performed prior to ERCP.
Anesthetic management of patients with implantable cardiac devices such as permanent pacemakers, automated implantable cardiac defibrillators, and cardiac resynchronization therapy devices should be managed per local, national, and international guidelines . Patients with left ventricular assist devices (LVAD) that require ERCP intervention should be managed by cardiac anesthesiologists or anesthesiologists familiar with these devices in consultation with cardiac anesthesia. If cardiac anesthesiologists are not available, these patients should be transferred to facilities where cardiac anesthesiologists or heart failure support can be obtained.
Patients on supplemental oxygen at home may require higher oxygen supplementation during sedation for ERCP. Additionally, they may also be candidates for intubation and general anesthesia in order to maintain proper oxygenation.
A history of obstructive sleep apnea can make deep sedation more difficult in patients in the prone position. Risk scoring scales such as STOP-BANG scoring system can identify patients at higher risk of adverse events during ERCP procedures . Risk factors include age >50 years, body mass Index >35 kg/m2, male gender, neck circumference >40 cm, hypertension, and history of snoring, tiredness/sleepiness, and observed apneas .
Severe liver dysfunction can impair coagulation factor synthesis and increase bleeding risk during ERCP. Moderate pancreatitis that has required fluid resuscitation may cause mild to moderate derangements in coagulation. Pancreatitis patients or patients with cholangitis may develop renal dysfunction which may lead to acute uremia and qualitative platelet dysfunction, further impairing coagulation.
Dosage and administration of oral or intravenous anticoagulants, antiplatelet agents, and direct thrombin inhibitors need to be confirmed prior to proceeding with ERCP.
A history of dementia or delirium related to the patient’s current medical conditions might make informed consent difficult or even impossible. Depressed or altered sensorium may place the patient at higher risk for aspiration and may necessitate utilization of general anesthesia
Frail, elderly patients are at higher risk for injury due to degenerative arthritis and osteoporosis. Patients may not be able to move themselves and moving them inappropriately may lead to injury. Arthritis of the neck may make oral cannulation difficult or even impossible in the prone position due to limited neck mobility.
Identification of hardware/scarring of the lower extremity is important for avoidance of placement of the dispersive pad for the electrosurgical unit required for sphincterotomy.
Patients with diabetes are at higher risk for cardiovascular complications. Hyperglycemia can occur in patients with pancreatic disorders due to injury to beta cells and decreased insulin production.
Non-diabetic patients who are bacteremic or septic may have glucose dysregulation and may be hyper- or hypoglycemic.
If patient suspects pregnancy, this should be investigated promptly prior to procedure initiation.
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An assessment of baseline neurologic function and level of consciousness is mandatory prior to proceeding with anesthesia for ERCP.
Vitals signs should be checked and recorded including measurements of blood pressure, heart rate, respiratory rate, and oxygen saturation in the presence and absence (if possible) of supplemental oxygen. Blood glucose should also be checked.
A directed physical examination based on the patient’s known active medical issues should be performed before the procedure.
Physical examination of the heart and lungs
Bronchospasm should be treated with beta-agonists prior to the procedure
The cause of rales on examination should be aggressively pursued prior to procedure (e.g. cardiac or non-cardiac causes)
Evidence of a consolidative process (pneumonia) warrants a discussion of risk/benefit of proceeding versus delaying procedure after initiating treatment for the consolidative process.
Significant cardiac abnormalities on exam such as the presence of a new systolic or diastolic murmur require further investigation.
A complete airway examination should be performed with documentation of the patient’s Mallampati score. This should be performed in conjunction with assessment for risk factors for obstructive sleep apnea. Additionally, patency of the nares is important in case placement of a nasopharyngeal airway is necessary.