1. Analgesia and Sedation in Endoscopic Surgery
Marina Yiasemidou
MSc Surgical Skills and Sciences

2. Aims of Sedation and Analgesia in Endoscopic Procedures
Reduce pt’s anxiety and discomfort
Safety
Thorough investigation
Medications of rapid onset, brief duration and fast recovery
Sufficient intra and post procedural monitoring
Cost effective

3. Sedation

4. Sedation Target state: Conscious (Moderate) Sedation
state of depression of the central nervous system which allows for the procedure to take place
verbal contact with the patient is maintained – If verbal contact is lost the pt should be monitored as if they were under general anaesthesia

5. Pre procedural assessment
Assessing Sedation risk
Significant cardiac or pulmonary disease
Neurologic or seizure disorder
Stridor, snoring, or sleep apnea
Adverse reaction to sedation or anesthesia
Current medications, drug and food allergies;
Alcohol or drug abuse
Time of last oral intake
ASA Score

6. ASA Classification
Class Description I The patient is normal and healthy II The patient has mild systemic disease that does not limit their activities (eg, controlled hypertension or controlled diabetes without systemic sequelae) III The patient has moderate or severe systemic disease, which does limit their activities (eg, stable angina or diabetes with systemic sequelae) IV The patient has severe systemic disease that is a constant potential threat to life (eg, severe congestive heart failure, end-stage renal failure) V The patient is morbid and is at substantial risk of death within 24 hours (with or without a procedure) E Emergency status: in addition to indicating underlying ASA status (1–5), any patient undergoing an emergency procedure is indicated by the suffix ”E”

7. Pre procedural assessment
ASA class I–III patients - sedation by an endoscopist.
Anesthesia specialist:
ASA classes IV and V patients
Emergency endoscopic procedures
Complex endoscopic procedures
Retrograde cholangiopancreatography
Endoscopic ultrasound
History of:
Adverse reaction to sedation
Alcohol or substance abuse
Inadequate response to moderate sedation

8. Pre procedural assessment
Fasting strictly for sedation reasons
ASA :clear fluids 6hrs, NBM 2hrs
Physical examination:
Vital signs and weight
Auscultation of heart and lungs
Baseline level of consciousness, and
Assessment of airway
Identify patients with anatomy that may make positive-pressure ventilation more difficult (obesity, short thick neck, cervical spine disease, decreased hyoid-mental distance, and structural abnormalities of the mouth, jaw, and oral cavity)

9. Mallampati Score Picture A - Class 1 Score Picture B - Class 2 Score
Picture C -Class 3 Score
Picture D - Class 4 Score
Class 1: Full visibility of tonsils, uvula and soft palate Class 2: Visibility of hard and soft palate, upper portion of tonsils and uvula Class 3: Soft and hard palate and base of the uvula are visible Class 4: Only Hard Palate visible

10. Sedation Techniques IV route
Exact doses are variable – Min dose were possible
PAIN=ANALGESICS
Fentanyl
Pethidine
Opioids before diazepines (Colonoscopy and ERCP)
Should be able to observe effect
Titrate BZP dose - up to 4 fold decrease
Synergy – Cardiovascular events
Availability of antagonists/resuscitation equipment
Flumazenil takes several min to reverse respiratory depression
Repeated administration may be necessary

11. Sedation Techniques
All pts undergoing IV sedation should have a flexible (not “butterfly”) IV cannula kept in place until recovery.
Other Sedative drugs commonly used
Propofol Should never be used without the presence of
Ketamine a trained anaesthetist
Entonox: 50/50 mixture of nitrous oxide and O2
Good analgesic
Little hypnotic effect
Mask or mouthpiece via a demand mask
Compliance - Stops as sedation begins

12. Sedation Techniques Difficult pts Not safe:
Compromised respiratory function
Pneumothorax
Best suited for colonoscopy or flexible sigmoidoscopy
Rapid recovery: Washout time: 5-10 min
Difficult pts
Restless and Violent pts
GA is the better option if anticipated
Reverse sedation if procedure already begun
Alcoholics
Cannot be sedated with benzodiazepines
Prior administration of opioid

13. Monitoring
For pts under sedation saturation <90% is dangerous and requires immediate intervention.
Endoscopist
Clinical monitoring
Trained nurse
Pre-oxygenation with O2 enriched air (2L/min)
Safe even in COPD
Prevents hypoxaemia
SHOULD BE USED ROUTINELY

14. Monitoring Pulse Oximetry ALWAYS Alarm System Desaturation
Clinical observations should still be employed
High cardiac risk + Continuous ECG monitoring and BP monitoring
Desaturation
Encourage pt to breath deeply with supplemental O2
Termination of procedure
Assisted Ventilation
Pharmacological Reversal of diazepine/opioid

15. Patient Recovery
Clinical monitoring must be continued into the recovery period
Respiratory complications such as aspiration pneumonia may present many hours or even days after the endoscopy.
Endoscopist is still responsible
Day cases should be accompanied home by a responsible adult who should then stay with them for at least 12 hours if they live alone.
Written instructions
Patients who have been sedated with an intravenous benzodiazepine should not drive a car, operate machinery, sign legal documents or drink alcohol for 24 hours.

16. Patient Recovery-Aldrete Scoring
Score ≥ 9: Can be discharged

17. Review of common drug agents
Midazolam is currently the corner stone of endoscopy sedation
Several times more potent than diazepam
Excellent amnesia
Inexpensive
5mg is the recommended max dosage
Elderly pts are given 1-2mg with a considerable pause to observe effects

18. Review of common drug agents
Opioids: Pethidine – Fentanyl
Pethidine has greater synergistic effect on sedation when given in combination with midazolam
Higher rates of postprocedural emesis, nausea and reduced pt functioning
Pethidine and Fentanyl dosage does not usually exceed 50mg and 100mg respectively
Elderly pts will require dose reduction (usually below 50%)

19. Review of common drug agents
Propofol
Anaesthetic agent
Acts via releasing aminobutyric acid in the brain
Fast onset, short action, rapid recovery
Can be titrated so as to produce deep sedation or general anaesthesia
Difficult to use as a single agent for moderate anaesthesia
Colonoscopy: Unpredictable reflex responses to pain
Upper Endoscopy: Oesophageal intubation initiates coughing
Pts that cannot be sedated with opioids and benzodiazepines – small amounts of propofol or droperidol

20. Review of common drug agents
Droperidol
Active alcohol or substance abuse
Produces prolonged QT arrythmias
Pre procedural ECG
Continuous monitoring during the procedure
When contra indicated
Diphenhydramine or
Promethazine (prolonged sedative effect)

21. Review of common drug agents
The antagonists
Naloxone
Opioid antagonist
Ventilatory depression, excessive sedation and analgesia
Dose of mg IV
Onset 1-2 min, half life min
Monitor for up to 2 hours
Caution for drug withdrawal symptoms in chronic opioid drug abusers

22. Review of common drug agents
Flumazenil
GABAA receptor complex BZP antagonist mg
Half life = hrs
Reversal of respiratory depression 2min
BZP has longer time of action – Repeated administration might be necessary

23. References
Implementing and ensuring Safe Sedation Practice for Healthcare Procedures in adults. Report of a Working Party established by the Royal College of Anaesthetists, November 2001
Sedation for Endoscopy. Douglas K. Rex.Division of Gastroenterology, Indiana University Medical Center, Indianapolis, Indiana
&id=6894
AGA Institute Review of Endoscopic Sedation. LAWRENCE B. COHEN, MARK H. DELEGGE, JAMES AISENBERG, JOEL V. BRILL, JOHN M. INADOMI, MICHAEL L. KOCHMAN, and JOSEPH D. PIORKOWSKI JR

24. Thank you