Sedation and Monitoring of Patients Undergoing Gastrointestinal
Endoscopic Procedures
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 in
common clinical situations. The Standard of Practice Committee Of the American Society for
Gastrointestinal Endoscopy prepared the text. An initial draft was distributed to all ASGE
members for comment. Each comment was considered by the Committee, and a final document
produced. In addition, the text was submitted for review and endorsement by the Governing
Boards of the American Gastroenterological Association, the American College of
Gastroenterology and the Society of American Gastrointestinal Endoscopic Surgeons.
Guidelines for the appropriate practice of endoscopy are based upon a critical review of the
available data and expert consensus. Controlled clinical studies are needed to clarify aspects of
this statement, and revision may be necessary as new data appear. Clinical considerations may
justify a course of action at variance from these recommendations."
It is the responsibility of every practitioner engaged in the performance of endoscopic
procedures to maximize benefit and safety to the patient. In endoscopy, better understanding of
the 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 patient
safety. This guideline is intended to review monitoring objectives and to recommend methods of
monitoring patients who receive endoscopic procedures.
Background
Gastrointestinal endoscopy with sedatives and analgesics by a trained endoscopist has proved
to be a safe procedure. Significant complications can occur as a result of instrumentation, such
as bleeding, perforation and infection, with a frequency that approximates 0.1% for upper
endoscopy and 0.2% for colonoscopy1,2,3. The risk for therapeutic procedures, endoscopic
retrograde cholangiopancreatography (ERCP) and emergency procedures may be considerably
higher 4. Cardiopulmonary complications may account for over 50% of the reported
complications, with the majority due to aspiration, over-sedation, hypoventilation, vasovagal
episodes, 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 at
increased risk from sedation6,7. These patients may require more complex or intensive
monitoring during endoscopic procedures. Patients who are taking sedative or anxiolytic
medications, opiates and a variety of other medications may also be at a greater risk for oversedation.
The safe use of sedation for endoscopic procedures in children requires special training and
attention and is beyond the scope of this document.
The use of monitoring personnel and equipment does not replace clinical evaluation and
assessment prior to the administration of sedatives and/or analgesics. In general, the lowest
possible dose of medication needed to achieve adequate patient comfort is to be used.
Definitions
For the purposes of this guideline, endoscopic procedures include any endoscopic procedure
employing medications for sedation and/or analgesia. Procedures that require general
anesthesia are beyond the scope of this monograph. For procedures performed without
medications, 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 to
the 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 that
their health permits safe use of these medications. In general, the most intense monitoring is
performed in the highest risk patients
Adverse reactions increase in frequency with the complexity of the procedure. Endoscopic
retrograde cholangiopancreatography (ERCP), emergency and therapeutic procedures (control
of bleeding, polypectomy, laser treatment, stent placement) all confer higher risk to the
patient1,5,8. 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 that
appropriate resuscitive measures can be instituted.
Sedation is defined as a reduction in the level of consciousness induced by medications used to
facilitate acceptance of endoscopic procedures. Sedation may range from minimal or no visible
change in patient status to loss of consciousness and protective reflexes. For some patients, no
sedation may be required, and topical anesthesia may suffice for upper endoscopic procedures.
Most endoscopists prefer to perform endoscopic procedures with the aid of intravenous
sedatives8.
Analgesia is the reduction in pain or perception of nociceptive stimuli induced by the use of
medication, primarily opiates, Analgesics are commonly used in low or moderate doses to
reduce discomfort without impairment in consciousness, but in higher doses can depress
respiration and induce sedation. Patients who are given analgesics in doses that suppress
ventilatory drive or impair protective reflexes achieve a state of consciousness equivalent to that
of general anaesthesia.
Good patient care includes assessment of patient well-being before, during and after
endoscopic procedures. By necessity, patient safety assumes that adequate facilities, as well as
endoscopic and resuscitation equipment, are available. It is also assumed that the procedure
will 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 readily
available.
Monitoring is the continuous assessment of the patient's status before, during and after the
administration of sedatives for the purpose of endoscopic procedures. Monitoring should detect
early signs of patient distress before compromise to vital functions occurs. This may include
significant changes in pulse, blood pressure, ventilatory status, cardiac electrical activity, clinical
and neurologic status.
Many components of patient well-being can be monitored by the endoscopist or assistant, but
assessment of ventilatory status has been shown to be enhanced by determination of the
patient's oxygenation status. Pulse oximetry provides the most commonly used method to
determine oxygen saturation.
While electronic monitoring equipment often facilitates assessment of patient status, it does not
replace a well-trained and vigilant assistant.
Pre-procedural Assessment
All patients undergoing endoscopic procedures require pre-procedural evaluation to determine
relative risk, to optimally manage problems related to pre-existing medical conditions, and to
allow 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 at
the time of the procedure are necessary to adequately provide for the safety of the patient. Such
information must be readily available to the endoscopist and those providing post-procedural
care.
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 reduced
anxiety. Substantial changes, however, and reductions below the range of normal require
assessment, and intervention if the patient is judged to be in distress.
The use of intravenous sedatives and/or analgesics for endoscopy requires continuous
intravenous access until the patient has recovered. This can be accomplished with an indwelling
catheter with or without intravenous fluid administration. Placement should be accomplished in
such a manner to allow operator access, but also to minimize the danger of accidentally
dislodging the cannula during the procedure.
Sedation
Studies have demonstrated improvement in patient satisfaction and comfort when intravenous
sedation is used during endoscopic procedures6. The choice of sedative is largely operator
dependent, but generally consists of benzodiazepines used either alone or in combination with
an opiate. Topical anesthesia may also be used to reduce gagging in cases involving peroral
esophageal intubation.
Benzodiazepines are used in the majority ot endoscopic procedures. They can induce
relaxation, cooperation and occasionally provide an amnestic response. Doses are titrated to
patient tolerance depending upon age, other illnesses, use of additional medications, and the
level of complexity of the procedure. In addition to the desired effects, significant respiratory
depression can occur. This effect is synergistically increased with the use of intravenous
opiates10.
Opiates administered intravenously provide both analgesia and sedation. As with
benzodiazepines, doses require titration to patient tolerance which can be affected by patient
factors. Respiratory depression occurs with opiates whether they are used alone or in
combination with other sedatives.
Opiates and benzodiazepines should be administered slowly and in small increments with
adequate time for the sedative effects of the injected dose to be apparent before additional
medications are given.
Specific antagonists of opiates (naloxone) and benzodiazepines (flumazenil) are available and
should be present in every endoscopy unit. The effect is not instantaneous and often of shorter
duration than the sedative drug, so that repeat injections may be necessary It is not prudent to
rely on the antagonists to compensate for over-sedation, as the risks of hypoventilation and
injury may be increased. The most appropriate use for these medications in the setting of
endoscopic practice appears to be for those patients who experience greater than expected
effect from the administered sedative. Administration of antagonists following endoscopic
procedures will not obviate the need for appropriate post-procedure observation and safe
discharge planning.
Assistants
It is impossible for the endoscopist to be fully cognizant of the patient's status while performing
endoscopic procedures. The use of a well-trained assistant is mandatory to continuously assess
patient well-being and often can facilitate improved patient comfort through reassurance. When
the complexity of the procedure demands that the attention of both the endoscopist and the
assistant be diverted from monitoring, a second assistant should be employed.
Automated Monitoring Devices
Most endoscopists are currently employing electronic monitoring equipment. Devices are
available that can monitor and display pulse, blood pressure, oxygen saturation and continuous
electrocardiographic (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 during
endoscopic procedures. However, they are not to be relied upon to provide complete
assessment of patient's well-being and cannot replace direct assessment by a qualified
assistant
Ventilatory status, however, cannot be reliably monitored by observation, particularly in a
darkened endoscopy room. A pulse oximeter or oxygen saturation monitor enhances the
assessment of ventilatory status in patients under sedation and/or analgesia.11
Monitoring oxygen saturation is prudent in high risk patients or procedures even if sedation is
not given, such as elderly or frail patients in whom a large caliber endoscope is used, and
patients with severe compromise of pulmonary function. The use of available monitoring
devices to help insure patient safety is encouraged and supported.
Procedural Monitoring
Standard monitoring of sedated patients undergoing gastrointestinal endoscopic procedures
includes recording the heart rate, blood pressure, respiratory rate, and oxygen saturation before
sedation. The heart rate and blood pressure should be monitored during the procedure, as well
as after it, until the patient is stable. Oxygen saturation is to be monitored continuously during
the procedure and until the patient is stable after the procedure.
Continuous EKG monitoring is reasonable in high-risk patients, although the necessity for such
monitoring has not been show conclusively in controlled trials. Patients who may benefit from
EKG monitoring include those who have a history of significant arrhythmia or cardiac
dysfunction, elderly patients and those in whom extensive procedures are anticipated.
Supplemental oxygen administration has been shown to reduce the magnitude of oxygen
desaturation when given during endoscopic procedures utilizing sedation 12,13. Its use should be
considered in high-risk patients, those with impairment of pulmonary function or significant presedation desaturation, and those in whom prolonged or complex procedures is anticipated.
Care must be taken to avoid suppression of hypoxic ventilatory drive, which can lead to
profound hypercapnea, as one recent study has reaffirmed. 14
The endoscopy record should reflect any technical problems during the procedure, and any
significant patient events such as emesis, respiratory distress, vagal reaction or diaphoresis, as
well as any intervention taken.
Post-procedure Monitoring
Following completion of endoscopic procedures, patients are to be observed for adverse effects
from either instrumentation or sedation. The length of the follow-up observation is dependent
upon the perceived risk to the patient. The duration of hypoxia may be prolonged well beyond
the completion of the procedure.15
Patients may be discharged from the endoscopy unit or post-procedure recovery area once vital
signs are stable and the patient has reached an appropriate level of consciousness. Despite the
appearance of appropriate recovery, it is well recognized that patients may have a prolonged
period of amnesia and / or impaired judgment and reflexes following intravenous medications
administered to induce sedation.
Patients should be advised prior to the administration of sedatives that a prolonged period of
impaired cognition may occur. They should be instructed to make plans not to drive, operate
heavy or potentially harmful machinery, or make legally binding decisions. When sedatives are
administered, patients must be accompanied by a competent companion for discharge from the
recovery area.
Written instructions upon discharge are necessary as the amnestic period following sedation is
variable. Post-procedure instruction on the signs and symptoms of potential adverse outcomes
and complications is also advisable. Patients should be given written instructions on steps to
follow in the event of a complication, including a phone number where 24-hour-a-day coverage
is available in the event of an emergency.
Summary
Every available means to insure the safety of patients during endoscopic procedures is
mandatory. This begins with a fully trained and knowledgeable endoscopist, thorough
preparation of the unit to handle endoscopic procedures and potential adverse outcomes,
appropriate patient preparation, skilled assistants, and monitoring of the patient's well-being
before, during and after the procedure.
The relative risks involved can be estimated from patient and procedural factors and should be
determined for each procedure. The level and type of monitoring during endoscopic procedures
is dependent upon a thorough understanding and assessment of the risk to the patient.
Monitoring of patients undergoing endoscopic procedures is mandatory and prudent. The
ultimate responsibility for protecting patients lies with the endoscopist and cannot be assigned
to an assistant or electronic monitoring device. However, both may greatly improve the ability to
detect 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.
13. Griffin SM, Chung SCS, Leung JWC et al: Effect of intranasal oxygen on
hypoxia and tachycardia during endoscopic cholangiopancreatography. Br Med
J 1990;300:83-4.
14. Freeman ML, Hennessy JT, Cass OWand Pheley AM: Carbon dioxide retention
and oxygen desaturation during gastrointestinal endoscopy. Gastroenterology
1993;105:3319.
15. Murray AK Morran CG, Kenny GNC et al: Arterial oxygen saturation during
upper gastrointestinal endoscopy: the effects of a midazolam/pethidine
combination. Gut 1990;31:270-3.
ASGE Publication No.1022
8/89
Revised 9/02
IMPORTANT REMINDER:
The preceding information is intended only to provide general information and not as a
definitive basis for diagnosis or treatment in any particular case. It is very important that
you consult your doctor about your specific condition.
© ASGE, 2005. For reprint information please contact info@asge.org
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