ASGE- SEDATION AND MONITORING OF PATIENTS.doc.doc.doc
Sedation and Monitoring of Patients Undergoing Gastrointestinal EndoscopicProcedures Background Definitions Pre-procedural Assessment Sedation Assistants Automated Monitoring Devices Procedural Monitoring Post-procedure Monitoring Summary References"This is one of a series of statements discussing the practice of gastrointestinal endoscopy incommon clinical situations. The Standard of Practice Committee Of the American Society forGastrointestinal Endoscopy prepared the text. An initial draft was distributed to all ASGEmembers for comment. Each comment was considered by the Committee, and a final documentproduced. In addition, the text was submitted for review and endorsement by the GoverningBoards of the American Gastroenterological Association, the American College ofGastroenterology and the Society of American Gastrointestinal Endoscopic Surgeons.Guidelines for the appropriate practice of endoscopy are based upon a critical review of theavailable data and expert consensus. Controlled clinical studies are needed to clarify aspects ofthis statement, and revision may be necessary as new data appear. Clinical considerations mayjustify a course of action at variance from these recommendations."It is the responsibility of every practitioner engaged in the performance of endoscopicprocedures to maximize benefit and safety to the patient. In endoscopy, better understanding ofthe risks and potential adverse outcomes has led to substantial advances in patient monitoring.However, monitoring of patients during endoscopic procedures is only part of optimizing patientsafety. This guideline is intended to review monitoring objectives and to recommend methods ofmonitoring patients who receive endoscopic procedures.BackgroundGastrointestinal endoscopy with sedatives and analgesics by a trained endoscopist has provedto be a safe procedure. Significant complications can occur as a result of instrumentation, suchas bleeding, perforation and infection, with a frequency that approximates 0.1% for upperendoscopy and 0.2% for colonoscopy1,2,3. The risk for therapeutic procedures, endoscopicretrograde cholangiopancreatography (ERCP) and emergency procedures may be considerablyhigher 4. Cardiopulmonary complications may account for over 50% of the reportedcomplications, with the majority due to aspiration, over-sedation, hypoventilation, vasovagalepisodes, and airway obstruction 5,6.Patients who are elderly or who have concomitant medical problems, including cardiovascular,pulmonary, renal, hepatic, metabolic and neurologic disorders, and morbid obesity, may be atincreased risk from sedation6,7. These patients may require more complex or intensivemonitoring during endoscopic procedures. Patients who are taking sedative or anxiolyticmedications, opiates and a variety of other medications may also be at a greater risk for over-sedation.The safe use of sedation for endoscopic procedures in children requires special training andattention and is beyond the scope of this document.The use of monitoring personnel and equipment does not replace clinical evaluation andassessment prior to the administration of sedatives and/or analgesics. In general, the lowestpossible dose of medication needed to achieve adequate patient comfort is to be used.
DefinitionsFor the purposes of this guideline, endoscopic procedures include any endoscopic procedureemploying medications for sedation and/or analgesia. Procedures that require generalanesthesia are beyond the scope of this monograph. For procedures performed withoutmedications, it is still prudent to utilize varying levels of monitoring as the situation demands.The risk to the patient of an adverse event during endoscopic procedures can be attributed tothe medication employed and to the procedure itself. While the risk of adverse events is low,patients should be assessed prior to administration of sedatives or analgesics to be certain thattheir health permits safe use of these medications. In general, the most intense monitoring isperformed in the highest risk patientsAdverse reactions increase in frequency with the complexity of the procedure. Endoscopicretrograde cholangiopancreatography (ERCP), emergency and therapeutic procedures (controlof bleeding, polypectomy, laser treatment, stent placement) all confer higher risk to thepatient1,5,8. Appropriate attention to patient monitoring before, during and after the procedure,will help to minimize complications as well as recognize early signs of distress, so thatappropriate resuscitive measures can be instituted.Sedation is defined as a reduction in the level of consciousness induced by medications used tofacilitate acceptance of endoscopic procedures. Sedation may range from minimal or no visiblechange in patient status to loss of consciousness and protective reflexes. For some patients, nosedation may be required, and topical anesthesia may suffice for upper endoscopic procedures.Most endoscopists prefer to perform endoscopic procedures with the aid of intravenoussedatives8.Analgesia is the reduction in pain or perception of nociceptive stimuli induced by the use ofmedication, primarily opiates, Analgesics are commonly used in low or moderate doses toreduce discomfort without impairment in consciousness, but in higher doses can depressrespiration and induce sedation. Patients who are given analgesics in doses that suppressventilatory drive or impair protective reflexes achieve a state of consciousness equivalent to thatof general anaesthesia.Good patient care includes assessment of patient well-being before, during and afterendoscopic procedures. By necessity, patient safety assumes that adequate facilities, as well asendoscopic and resuscitation equipment, are available. It is also assumed that the procedurewill be performed in the presence of appropriately trained and competent assisting staff.Emergency assistance as well as transport to local intensive care units should also be readilyavailable.Monitoring is the continuous assessment of the patients status before, during and after theadministration of sedatives for the purpose of endoscopic procedures. Monitoring should detectearly signs of patient distress before compromise to vital functions occurs. This may includesignificant changes in pulse, blood pressure, ventilatory status, cardiac electrical activity, clinicaland neurologic status.Many components of patient well-being can be monitored by the endoscopist or assistant, butassessment of ventilatory status has been shown to be enhanced by determination of thepatients oxygenation status. Pulse oximetry provides the most commonly used method todetermine oxygen saturation.While electronic monitoring equipment often facilitates assessment of patient status, it does notreplace a well-trained and vigilant assistant.Pre-procedural AssessmentAll patients undergoing endoscopic procedures require pre-procedural evaluation to determinerelative risk, to optimally manage problems related to pre-existing medical conditions, and toallow appropriate post-procedural care in the event of an adverse reaction. A brief history,
current rnedications and drug allergies, as well as an assessment of cardiopulmonary status atthe time of the procedure are necessary to adequately provide for the safety of the patient. Suchinformation must be readily available to the endoscopist and those providing post-proceduralcare.Pre-sedation vital signs and oxygen saturation are to be recorded and available for comparison.Sedation may lower pre-procedural blood pressure and pulse, often as a result of reducedanxiety. Substantial changes, however, and reductions below the range of normal requireassessment, and intervention if the patient is judged to be in distress.The use of intravenous sedatives and/or analgesics for endoscopy requires continuousintravenous access until the patient has recovered. This can be accomplished with an indwellingcatheter with or without intravenous fluid administration. Placement should be accomplished insuch a manner to allow operator access, but also to minimize the danger of accidentallydislodging the cannula during the procedure.SedationStudies have demonstrated improvement in patient satisfaction and comfort when intravenoussedation is used during endoscopic procedures6. The choice of sedative is largely operatordependent, but generally consists of benzodiazepines used either alone or in combination withan opiate. Topical anesthesia may also be used to reduce gagging in cases involving peroralesophageal intubation.Benzodiazepines are used in the majority ot endoscopic procedures. They can inducerelaxation, cooperation and occasionally provide an amnestic response. Doses are titrated topatient tolerance depending upon age, other illnesses, use of additional medications, and thelevel of complexity of the procedure. In addition to the desired effects, significant respiratorydepression can occur. This effect is synergistically increased with the use of intravenousopiates10.Opiates administered intravenously provide both analgesia and sedation. As withbenzodiazepines, doses require titration to patient tolerance which can be affected by patientfactors. Respiratory depression occurs with opiates whether they are used alone or incombination with other sedatives.Opiates and benzodiazepines should be administered slowly and in small increments withadequate time for the sedative effects of the injected dose to be apparent before additionalmedications are given.Specific antagonists of opiates (naloxone) and benzodiazepines (flumazenil) are available andshould be present in every endoscopy unit. The effect is not instantaneous and often of shorterduration than the sedative drug, so that repeat injections may be necessary It is not prudent torely on the antagonists to compensate for over-sedation, as the risks of hypoventilation andinjury may be increased. The most appropriate use for these medications in the setting ofendoscopic practice appears to be for those patients who experience greater than expectedeffect from the administered sedative. Administration of antagonists following endoscopicprocedures will not obviate the need for appropriate post-procedure observation and safedischarge planning.AssistantsIt is impossible for the endoscopist to be fully cognizant of the patients status while performingendoscopic procedures. The use of a well-trained assistant is mandatory to continuously assesspatient well-being and often can facilitate improved patient comfort through reassurance. Whenthe complexity of the procedure demands that the attention of both the endoscopist and theassistant be diverted from monitoring, a second assistant should be employed.Automated Monitoring DevicesMost endoscopists are currently employing electronic monitoring equipment. Devices are
available that can monitor and display pulse, blood pressure, oxygen saturation and continuouselectrocardiographic (EKG) rhythm assessment. The frequency of testing can be individualized,and most devices have alarms that alert the observer to changes outside the established range.The use of these devices does reduce the manual labor associated with monitoring duringendoscopic procedures. However, they are not to be relied upon to provide completeassessment of patients well-being and cannot replace direct assessment by a qualifiedassistantVentilatory status, however, cannot be reliably monitored by observation, particularly in adarkened endoscopy room. A pulse oximeter or oxygen saturation monitor enhances theassessment of ventilatory status in patients under sedation and/or analgesia.11Monitoring oxygen saturation is prudent in high risk patients or procedures even if sedation isnot given, such as elderly or frail patients in whom a large caliber endoscope is used, andpatients with severe compromise of pulmonary function. The use of available monitoring devicesto help insure patient safety is encouraged and supported.Procedural MonitoringStandard monitoring of sedated patients undergoing gastrointestinal endoscopic proceduresincludes recording the heart rate, blood pressure, respiratory rate, and oxygen saturation beforesedation. The heart rate and blood pressure should be monitored during the procedure, as wellas after it, until the patient is stable. Oxygen saturation is to be monitored continuously duringthe procedure and until the patient is stable after the procedure.Continuous EKG monitoring is reasonable in high-risk patients, although the necessity for suchmonitoring has not been show conclusively in controlled trials. Patients who may benefit fromEKG monitoring include those who have a history of significant arrhythmia or cardiacdysfunction, elderly patients and those in whom extensive procedures are anticipated.Supplemental oxygen administration has been shown to reduce the magnitude of oxygendesaturation when given during endoscopic procedures utilizing sedation 12,13. Its use should beconsidered in high-risk patients, those with impairment of pulmonary function or significant pre-sedation desaturation, and those in whom prolonged or complex procedures is anticipated. Caremust be taken to avoid suppression of hypoxic ventilatory drive, which can lead to profoundhypercapnea, as one recent study has reaffirmed.14The endoscopy record should reflect any technical problems during the procedure, and anysignificant patient events such as emesis, respiratory distress, vagal reaction or diaphoresis, aswell as any intervention taken.Post-procedure MonitoringFollowing completion of endoscopic procedures, patients are to be observed for adverse effectsfrom either instrumentation or sedation. The length of the follow-up observation is dependentupon the perceived risk to the patient. The duration of hypoxia may be prolonged well beyondthe completion of the procedure.15Patients may be discharged from the endoscopy unit or post-procedure recovery area once vitalsigns are stable and the patient has reached an appropriate level of consciousness. Despite theappearance of appropriate recovery, it is well recognized that patients may have a prolongedperiod of amnesia and / or impaired judgment and reflexes following intravenous medicationsadministered to induce sedation.Patients should be advised prior to the administration of sedatives that a prolonged period ofimpaired cognition may occur. They should be instructed to make plans not to drive, operateheavy or potentially harmful machinery, or make legally binding decisions. When sedatives areadministered, patients must be accompanied by a competent companion for discharge from therecovery area.
Written instructions upon discharge are necessary as the amnestic period following sedation isvariable. Post-procedure instruction on the signs and symptoms of potential adverse outcomesand complications is also advisable. Patients should be given written instructions on steps tofollow in the event of a complication, including a phone number where 24-hour-a-day coverageis available in the event of an emergency.SummaryEvery available means to insure the safety of patients during endoscopic procedures ismandatory. This begins with a fully trained and knowledgeable endoscopist, thoroughpreparation of the unit to handle endoscopic procedures and potential adverse outcomes,appropriate patient preparation, skilled assistants, and monitoring of the patients well-beingbefore, during and after the procedure.The relative risks involved can be estimated from patient and procedural factors and should bedetermined for each procedure. The level and type of monitoring during endoscopic proceduresis dependent upon a thorough understanding and assessment of the risk to the patient.Monitoring of patients undergoing endoscopic procedures is mandatory and prudent. Theultimate responsibility for protecting patients lies with the endoscopist and cannot be assignedto an assistant or electronic monitoring device. However, both may greatly improve the ability todetect patient distress at a time when intervention will prevent an otherwise adverse outcome.References 1. Keeffe EB: Complications of gastrointestinal endoscopy. In Gastrointestinal Disease, 5th Edition. Sleisenger MH and Fordtran JS, eds. WB Saunders Co., Philadelphia; 1993:301-8. 2. Carey WD: Indications, contraindications and complications of upper gastrointestinal endoscopy. In Gastroenterologic Endoscopy, Sivak Jr MV, ed. WB Saunders Co., Philadelphia; 1987:296-306. 3. Rankin GB. Indications, contraindications and complications of colonoscopy. In Gastroenterologic Endoscopy Sivak Jr MV, ed. WB Saunders Co., Philadelphia; 1987:868-80. 4. Gilbert DA, Silverstein FE, Tedesco FJ et al: National ASGE survey on upper gastrointestinal bleeding; complications of endoscopy. Dig Dis Sci 1981;26(suppl):55-9. 5. Silvis SE, Nebel O, Rogers G et al: Cardiopulmonary complications are more common than bleeding or perforation during diagnostic procedures. JAMA 1976;235:928-30. 6. Lieberman DA, Wuerker CK, Katon RM: Cardiopulmonary risk of esophagogastroduodenoscopy: role of endoscope diameter and systemic sedation. Gastroenterology 1985;88:468-72. 7. Bell GD, Spickett GP, Reeve PA et al: Intravenous midazolam for upper gastrointestinal endoscopy: a study of 800 consecutive cases relating dose to age and sex of patient. Br j Clin Pharinacol 1987;23:241-3. 8. Reiertsen O, Skjoto J, Jacobsen CD et al: Complications of fiberoptic gastrointestinal endoscopy-five years experience in a central hospital. Endoscopy 1987;19:1-6. 9. Daneshmind TK, Bell GD, Logan RFA: Sedation for upper gastrointestinal endoscopy: results of a nationwide survey. Gut 1991;32:12-5. 10. Ben-Shlomo J, Abd-El-Khalim H, Ezry J et al: Midazolam acts synergistically with fentanyl for induction of anaesthesia. Br J Anaesth 1990;64:45-7. 11. Council on Scientific Affairs, American Medical Association. The use of pulse oximetry during conscious sedation. JAMA 1993;270(12):1463-8. 12. Bell GD, Bown S, Morden A et al: Prevention of hypoxaemia during upper gastrointestinal endoscopy by means of oxygen via nasal cannulae. Lancet 1987;i:1022-4.