Sedation Issues for Endoscopy

1. Sedation Issues for Endoscopy Dr. Stephen Brown Past Chair - OMA Section on Anesthesiology Chief – North York General Hospital Department of Anesthesia Assistant Professor – U of T

2. Agenda • Desired outcomes • Bigger picture • Current practice • Sedation levels • Ideal drug • Pharmacology overview • Models of care

3. Desired Outcomes • Patient safety • Completion of endoscopic procedure • Patient cooperation • Rapid recovery • Patient satisfaction • “painless” procedure?

4. Bigger Picture • Patient Evaluation • Patient preparation • Monitoring • Recording parameters • Personnel, training • Emergency equipment

5. Bigger Picture • Supplemental Oxygen • Intravenous access • Drugs and reversal agents • Recovery and discharge

6. Current practice • Sedation is routinely provided to patients during colonoscopy • considered the standard of practice in the US and Canada • 98% of endoscopists routinely use Vicari JJ. Sedation and analgesia. Gastrointest Endosc Clin N Am 2002;12:297-311

7. Current practice • more likely to achieve cecal intubation with sedation • Up to 50% of procedures terminated because of pain when no sedation is used

8. Drawbacks to Sedation • Unintended deeper sedation level than intended • Cardiopulmonary complications • Delayed recovery and discharge • Increased cost

9. Continuum of Sedation • Minimal Sedation (Anxiolysis) • Light Sedation/Analgesia (Conscious Sedation) • Deep Sedation/Analgesia • General Anesthesia

10. Minimal Sedation • Minimal Sedation (Anxiolysis) is a drug-induced state during which patients respond normally to verbal commands. Although cognitive function and coordination may be impaired, ventilatory and cardiovascular functions are unaffected

11. Moderate Sedation • Moderate Sedation/Analgesia ("Conscious Sedation") is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.

12. Deep Sedation • Deep Sedation/Analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained

13. General Anesthesia • General Anesthesia is a drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation. The ability to independently maintain ventilatory function is often impaired. Patients often require assistance in maintaining a patent airway, and positive pressure ventilation may be required because of depressed spontaneous ventilation or drug-induced depression of neuromuscular function. Cardiovascular function may be impaired

14. Managing the Continuum • Not always possible to predict how an individual will respond • Practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended

15. Ideal Drug • Consistent action • Rapid onset, offset • Analgesic, amnestic, anxiolytic effects • reversible • Minimal risks or adverse events • Anesthesiologist not required

16. The Ideal Drug… DOESN’T EXIST Sedation and Anesthesia in GI Endoscopy (Guideline) Gastrointest Endosc 2008; 68:815-826

17. Medications

18. Fentanyl • Potent narcotic • Adult: 0.5 µg/kg IV up to 2µg/kg • Onset 1-2 min • Duration 30-60 minutes • Profound respiratory depression • Synergistic effect with benzos • nausea

19. Naloxone • 0.1 – 0.8 mg IV (1-4mcg/kg) • Duration 30 min • Cardiovascular stimulation

20. Midazolam • Benzodiazapine • Antero- and retrograde amnesia • Titrate 0.5-1.0 mg IV, 2 min between • Onset 2-4 min, max effect 5 min • Duration 15-80 minutes • Clearance reduced in elderly, obese, hepatic or renal impairment

21. Flumazenil • 0.2 mg IV over 15 seconds • Repeat if necessary every 60s – max 1mg • Caution in chronic benzo users • May not last as long as benzo – watch for re-sedation

22. Propofol • 1-2 mg/kg – GA • Sedation 0.5 mg/kg bolus or infusion 25-75 µg/kg/min • Onset: 20-30 seconds • Rapid redistribution • Exaggerated effects in hypovolemia, elderly, impaired LV function

23. Propofol • Duration of effect 4-8 minutes • No reversal agent

24. Choice of Medications • Versed/Fentanyl combination • Most appropriate mixture of benzos and opioids • No place for longer acting agents in outpatient facilities • Well-studied • Effects last longer than the procedure

25. Choice of Medications • Adjuncts such as Droperidol, diphenhydramine, ketamine, nitrous, promethazine not advisable • Highly variable response • Important adverse reactions • Please avoid

26. Choice of Medications • Propofol • Closest to ideal drug • Narrow therapeutic window • Used for 25% of endoscopies in US • 7.7% use without an anesthesiologist Cohen LB et al. Endoscopic sedation in the United States: results from a Nation-wide survey. Am J Gastroenterol 2006; 101:967-74

27. Propofol • Quickest time to sedation (1-2 min vs 7 min) • Quickest time to recovery (14.2 min vs 30.2 min) Sipe BW, Rex DK, Latinovich D, et al. Propofol versus midazolam/meperidine for outpatient colonoscopy: administration by nurses supervised by endoscopists. Gastrointest Endosc 2002;56:815-25.

28. Propofol • Quickest time to discharge (18 min vs 40 min) Walker JA, McIntyre RD, Schleinitz PF, et al. Nurse administered propofol sedation without anesthesia specialists in 9152 endoscopic cases in an ambulatory surgery center. Am J Gastroenterol 2003; 98:1744-50.

29. Propofol • Higher patient satisfaction Koshy G, et al. Propofol vs Midazolam and Meperidine for Conscious Sedation in GI Endoscopy. Am J Gastroenterol 2000;95:1476-9

30. Propofol • Less nausea and vomiting

31. Propofol - caveats • A sedation team with appropriate education and training in advanced airway skills, defibrillation, and the use of resuscitative medications Chutkan R, et al. Training Guidelines for use of Propofol in Gastrointestinal Endoscopy. Gastrointest Endosc 2004: 60;167-72

32. Propofol - caveats • Trained personnel dedicated to the uninterrupted monitoring of the patient’s clinical and physiologic parameters throughout the procedure

33. Propofol - caveats • Monitoring pulse oximetry, ECG, NIBP, consider capnography • Ability to rescue from general anesthesia

34. Who can use Propofol? • 68% of US endoscopists using conventional sedation indicate that they would like to use propofol, but are reluctant because of the additional risks, FDA recommendations, and medico-legal Cohen LB et al. Endoscopic sedation in the United States: results from a Nation-wide survey. Am J Gastroenterol 2006; 101:967-74

35. GD-P • Administered directly by GI doc • Administered by a specially-trained Nurse (NAPS) • Patient-controlled systems (PCS) • US only – presence of CRNA’s

36. Anesthesia Care Team Model • Team of Anesthesiologist, anesthesia assistants • Specially-trained RT or Nurse • In-house training or Michener AA Course • Safely cover multiple locations • Anesthesiologist is immediately available

37. Anesthesia as a Resource • Patient selection, evaluation • Protocols, monitoring, d/c criteria • Drug selection, emergency equipment • Staff training • Supervisory role • Direct patient care