Among lecture series of the Conscious Sedation Course at KFH, Al-Baha

1. Decreasing the
Risks Associated
with Conscious
Sedation
Wael Galal; M.D.
Anesthesia Consultant
KFH Al-Baha

2. Risk of Oversedation &
Cardiopulmonary
complications
Risk of patient
discomfort and distress
Safety

3. STATISTICS
(large observational studies)
• > 14,000,000 EGDs are performed
annually in the US alone
• Most of these done under conscious
sedation
• Many states in the US as well as other
countries forbid the use of propofol by
non-anesthesiologists
• The overall complication rate was 13.5
events per 1,000 procedures

4. • The rate of serious cardiacor-
respiratory complications was 5.4 per
1000
• Death was reported in 0.3 per 1,000
procedures
• There was no significant difference in the
rate of complications between patients
receiving midazolam and those receiving
diazepam

5. Data evaluating the safety and efficacy of
meperidine and diazepam or meperidine
and midazolam, when used for moderate
sedation during upper and lower GI
endoscopic procedures performed over 2-
year period:-
•Revealed no deaths
•There were no episodes of
cardiopulmonary arrest or pulmonary
aspiration reported in this series

6. A study using sedation-trained nurses
administering propofol to 36,743 patients
at three centers with a limited selection of
busy endoscopists reported:-
- No fatalities or intubations
- Only 0.1% to 0.2% needing assisted
ventilation
-----------------------------------------------------------
Other studies showed:-
- Greater risk of apnoea & hypotension
- Maladjustment of sedation easier
(Narrow therapeutic window)
- Airway manipulations more required

7. • Oxygen desaturation:
• Range around 45% with meperidine +
midazolam/diazepam
• Propofol < narcotic+opioid

8. • The use of combinations regimes or
opioid use increase the risks of:
- Oversedation
- Cardio-respiratory complications
(particularly hypoxemia respiratory and airway complications)
___________________________________
Morbid obesity
Older age
Underlying cardiovascular disease
Pulmonary disease
Renal, hepatic, metabolic disease
Neurologic disease

9. FACTS
• Any medical procedure imply a certain amount
of risk. It is the human nature which has the
tendency to look for “everything” in life as figures
of chances and odds.
• This risk can be attenuated to a minimum by
building experience, judicious steps, patient
selection, safety measures, careful monitoring
and good preparation
• Our target is to prevent the occurrence of these
risks and their progression to life-threatening
events

10. • Pulse oximetry is a monitor of oxygenation
and not ventilation
• Supplemental oxygen can mask apnea or
hypoventilation
• Reflex withdrawal from a painful stimulus
is not considered a purposeful response
• Medico-legal claims about conscious
sedation :
– Complications were caused by respiratory
depression (45%)
– Oversedation (> 1/3 of cases)
– Polypharmacy with another(s) drug with
propofol (> 1/3 of cases)

11. General life-associated Risks Incidence Rate
To be hit by a Tsunami 1 per 50,000-500,000
To be killed by an asteroid 1 per 200,000 - 500,000
Having a heart disease 1 every 5
Having cancer 1 every 7
Stroke 1 in 23
Accidental injury 1 in 36
MVA 1 in 100
Commit suicide 1 in 121
Assault by a firearm 1 in 325
Electrocution 1 every 5000
Drowning 1 in 8,942
Airplane crash 1 in 20,000 individuals or 1 plane
every 8 Million flights
Sting by a snake, bee or others 1 in 100,000
Being hit by lightening strike 1 in 83,930
Death from a car accident 1.7 in 10000 drivers

12. Medical Risk Incidence Rate
Cardiac arrest from administration of
anesthesia
4.6-19.7 per 10,000 anesthetics
Cardiac arrest during monitored anesthesia
care
0.7 per 10,000 procedures
Cardiac arrest during neuraxial anesthesia 1.8 per 10,000 cases
Cardiac arrest during regional anesthesia 1.5 per 10,000 cases
In-hospital mortality related to anesthesia Was 1:10,000-20,000
anesthetics 20 years ago to 0.5-
1.0 per 100,000 anesthetics
now!
Death during low-risk anesthesia 1 per 500,000 anesthetics
Mortality from two operator dependent
anesthesia
the risk went from 1:248,000 to
1:598,000
Death from conscious sedation* 1:500,000 - 1:1,000,000

13. Classification of Risk:-
“How to interpret different odds”
• 1 in 10 – Extremely High
• 1 in 100 – Very High
• 1 in 1,000 – Quite High
• 1 in 10,000 – Medium
• 1 in 100,000 – Quite Low
• 1 in 1 million – Very Low
• 1 in 10 million – Extremely Low
• 1 in 100 million – Minimal

14. Risks, Risks, Risks, …

15. Risks of Conscious Sedation
• Respiratory Depression
First sign is lack of response to verbal stimulation
• Cardiovascular Depression
• Oversedation
• Paradoxical Reactions
• Wrong patient, site and procedure
75%
25%

16. Primum non nocere
(primum nil nocere)
Latin phrase originated from the Hippocratic
oath that means:
"first, do no harm"
The Essence of Prediction and
Measuring Chances??
• Smith CM. Origin and uses of primum non nocere--above all, do no harm! J Clin Pharmacol.
2005 Apr;45(4):371-7.
• Oath (Primum non nocere): http://www.youtube.com/watch?v=94H0IlQnYa0

17. The rate of complications associated with
conscious sedation are increased
significantly with the combination of > 1
agent, with use of opioids and with the use
of advanced sedation techniques/agents
(e.g. involving propofol, dexmedetomidine,
… etc.)

18. • MAC: Monitored Anesthesia Care
• MAC: Maximal “Anesthetist”
Consumption
• MAC: Minimal Alveolar Concentration
• MAC: Maximal Anesthesia Caution!!

20. Procedural Sedation Risk Sources
1. Patients at risk (physician function)
2. Who administer sedation
3. Equipment failure (nurse function)
4. Monitoring failure
5. Unpredicted drug response
6. Wrong patient, wrong site, wrong
procedure

21. “At Risk” Patients Categories
• ASA status classification ≥ 3
• Critical care patients
• Extremes in age (<1 or >70 years of age)
• Patients with chronic respiratory disease, chronic
obstructive pulmonary disease, emphysema
• History of sleep apnea syndrome
• Mentally and neurologically disabled patients
• Patients at risk for aspiration (i.e. hiatal hernia with
regurgitation, diabetes with gastroparesis
• Altered mental status
• Obesity

22. Prevent Patient Risks

23. Prevent Risks
Prevent Complications
Timing: Pre-procedural
By: (A) Careful Patient Selection
(B) Completing patient, drugs & Equipment checlists
Timing: Intra-procedural
By: (A) Proper Patient Monitoring
(B) Proper Timley Intervention
(C) Use of Reversal Agents
(D) Fulfilling Discharge Criteria
1
2

24. Predictors of Conscious Sedation-
Related Complications*
• ASA Classification ≥ III
• Inpatient procedures
• Involvement of trainees
• Use of supplemental oxygen
* This is studied in relation to cardiopulmonary events
•Number of studied subjects 324,737 endoscopic procedures

25. How to Identify them?
Easy … Never hesitate!
Physician’s pre-sedation patient evaluation should utilize a checklist
function to identify patients at risk.

26. Patient Selection for Conscious Sedation
• History:
- Any poor anesthetic or Sedational history
- Documented difficult airway
- History of snoring/obstruction/cynosis
during sleep
- Full stomach or upper GI bleeding

27. • Physical Examination
– Respiratory distress (wheezing, stridor, etc.)
– Hypotension
– Morbid obesity
– Craniofacial abnormalities
– Short neck
– Decreased hyoid-mental distance (<3cm in
adult)
– Distorted landmarks on anterior surface of
neck

28. – Limited mouth opening
– Receding chin
– Large tongue
– Unable to view base of uvula with mouth open
and tongue protruding

29. Now we can
figure out the
ASA class??

30. Modifying Fasting Guidelines
Intake Category Fasting Period for Low
Risk Patients
Fasting Period for High
Risk Patients
Clear Liquids 2 hours 8 hours
Breast Milk 4 hours 8 hours
Infant Formula 6 hours 8 hours
Non-human Milk 6 hours 8 hours
Regular Meal 8 hours 8 hours

31. Who Administers Sedation?
1) Minimum one physician and one nurse
2) Certified in BLS. It should be periodically
updated according to the SCFHS standards.
3) Should have certified basic training in
sedation obtained from approved courses.
including training in managing crises and
complications.
4) The certification is valid for only two years
and should be periodically renewed.

32. Proper Monitoring of Risks
Respiratory Cardiovascular
ParadoxesOversedation
Observation, RR,
SpO2, EtCO2
ECG, BP, HR
Observe Level of
Consciousness
Observe
Behavioral
Response

33. Prevent Equipment Failure
• Check ALL EQUIPMENT before
beginning any procedure.
• USE CHECKLISTS (nursing checklist will
target all equipment and drugs)

35. • General
Description
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
The Risk of Oversedation

36. Minimal
• General
Description
“Anxiolysis”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
unaffected
unaffected
unaffected
SEDATION LEVELS
Risk
of
Adverse
Event
No
Sedation
Mild
Sedation
The Risk of Oversedation

37. Minimal Moderate
• General
Description
“Anxiolysis” “Conscious”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
unaffected
unaffected
unaffected
“Purposeful” to light
stimulation
No intervention
Adequate
Maintained
SEDATION LEVELS
Risk
of
Adverse
Event
No
Sedation
Mild
Sedation
Moderate
Sedation
The Risk of Oversedation

38. Minimal Moderate Deep
• General
Description
“Anxiolysis” “Conscious” “Deep sleep”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
Unaffected
Unaffected
Unaffected
“Purposeful” to light
stimulation
No intervention
Adequate
Maintained
“Purposeful” to pain
stimulation
(±) Intervention
(±) Inadequate
(±) Maintained
SEDATION LEVELS
Risk
of
Adverse
Event
No
Sedation
Mild
Sedation
Moderate
Sedation
Deep
Sedation
The Risk of Oversedation

39. • Use agents with wide therapeutic window
• Minimize combination regimes
• Minimize use of unrequired narcotics
• TALK to YOUR PATIENT
Oversedation

40. Management of Sedational
Complications:
Active Interventions

41. • Stimulate the patient to wake up and take deep breaths. It
is not sufficient to simply turn up the rate of oxygen delivery.
• If the patient does not respond, chin lift and jaw thrust is
appropriate to provide a patent airway.
• Administer the appropriate antagonist (flumazenil for
benzodiazepines; naloxone for opioids).
• If there is still no response to these measures, consider the
use of bag mask ventilation as the next measure. Insertion
of a nasopharyngeal of oropharyngeal airway may augment
ventilation at this stage.
• The use of laryngeal mask airway or ET tube insertion as
appropriate should then be considered.
Respiratory Depression

42. • Intravenous fluids
• Atropine sulphate
• Vasopressor agents
– Ephedrine
• Antidysrhythmic agents (Consult!!)
Cardiovascular Depression

43. • Increasing sedation
• Adding an opioid agent to relief possible pain
Vasopressor Response

44. • Stop administering sedating agents
• Maintain A …. B …. C
• Use the specific reversal agents
• Consult!!
Oversedation

45. • A state of excitement can occur in some patients as a
reaction to sedation agent(s) which can prevent the
performance of the targeted procedure.
• These reactions can include excessive talkativeness,
movement, and emotional release.
• Relatively uncommon, occurring in less than 1% of cases.
Paradoxical Reactions

46. Predisposing Factors for
Paradoxical Responses
Predisposing Patient Characteristics:
•Young and advanced age
•Genetic predisposition
•Alcoholism or drug abuse
•Psychiatric and/or personality disorders
Predisposing Pharmacologic
Agents:
•Diazepam > Midazolam
•Sole ketamine sedation

47. Management of Paradoxical
Reactions
• STOP the culprit agent. Additional doses of
benzodiazepines and opioids usually worsen the
problem.
• Flumazenil, a benzodiazepine antagonist, has
been shown to be effective in managing these
reactions with a minimum of side effects.
• In some cases, the addition of droperidol may
resolve the problem, but often propofol will need
to be administered for better control

48. • Lidocaine is commonly used to suppress the
gag reflex during upper GI endoscopic
procedures via spray or gargling.
• This use was associated with severe adverse
reactions including rare cases of fatal
methemoglobinemia, causing cyto-toxic hypoxia.
• Methemoglobinemia should be suspected if
clinical “cyanosis” is observed in the presence of
normal arterial oxygen saturation.
Complications of LA agents

49. • Blood color ranges from dark red or
brownish to blue. Pulse oximetry is not
effective in measuring oxygen saturation
in the presence of methemoglobinemia.
High flow oxygen and possibly the use of
IV methylene blue (2mg/kg) can be used
to treat methemoglobinemia.

50. • The ASGE Guidelines for Conscious
Sedation and Monitoring During
Gastroenterology recommends against
the routine use of topical pharyngeal
anesthetics in most patients. However,
pharyngeal anesthesia before upper
endoscopy improves ease of endoscopy
and also improves patient tolerance, so
may be acceptable under certain
conditions, especially if light or no
sedation is administered.

51. Development of Conscious Sedation
Clinical Pathway
An evidence-based conscious sedation clinical pathway

54. The 10 Unaccepted Safety Breeching
Situations
1. Unfamiliarity of the physician about any
patient’s related comorbid condition or drug
allergy
2. Breaking the NPO guidelines
3. Unfamiliarity of all sedation parties with
drug dosing and concentrations
4. Once started, all parties must remain at the
patient’s bed-side
5. Unavailability of emergency drug or
reversal agent

55. 6. Pushing advanced use agents like propofol
or dexmedetomidine by syringe
7. Last moment decision change particularly
omitting procedural sedation based on wrong
suggestion
8. Ignoring the ASA status implications
9. Treating “reversed sedation” patients like
regular cases
10. Assuming conscious sedation necessarily
implicates amnesia

56. Any Questions
?

57. Summary
• Choose your patient carefully, learn about his/her
body weight and comorbidities.
• Check and understand your drugs, monitoring and
resuscitation equipment
• Use medication judiciously, remember you can’t
take it out but you can always give more!
• Have reversal agents available but always
remember basic resuscitation techniques.
• Be vigilant and prepare for the unexpected.

58. Measures for
Risk Reduction Associated with
Conscious Sedation

59. Causes of complications
Associated with Conscious Sedation Agents
• Inappropriate patient selection
• Unanticipated response
• Inappropriate monitoring of
pharmacological effects
• Equipment failure
• Over-medication (or over-sedation)

60. Improve Patient Selection
• Use the ASA classification
• Assess airway
• Assess neurologic, psychological, and
cardiorespiratory fitness
• Follow NPO guidelines

61. Prepare for Unexpected Events
• Anticipate for known abnormal
reactions
• Adequate preparation & checkup of all
necessary equipment
• Call for help
• Basic/Advanced life support

62. Adequate Monitoring of Drug Effects
• Establish standard monitoring for ALL
CASES
• Maintain continual patient contact and
observation
• Never forget: First monitor is
Continual Monitoring/Observation of
the Level of Consciousness ?
(maintain verbal contact with your

63. • Use conscious sedation equipment
checklist prior to every single procedure
• Record the checklist in each patient
record
Prevention of Equipment Failure

64. Prevention of Oversedation
• Use standard drug dosage and precautions
(use distributed leaflets)
• Titrate dosage to response
• Allow enough time to a drug to appear
• Get reversal agents as well as other
emergency drugs in reach of your hand
• Basic/Advanced life support

65. Prevention of Risks
Respiratory Cardiovascular
ParadoxesOversedation
- Proper patient selection & monitoring
- Proper checkup of all necessary equipment and drugs
- Skill &Tools in opening the airway, assisting ventilation & supporting
hemodynamics (i.e. valid BLS/ACLS certification)
- Periodic Mock codes
- Secure Method for calling for help prior to each procedure
- Use dosing guidelines and strategies
- Minimize the use of multiple agents
- Minimize the use of opioids
- Discontinue sedation agents & use
reversal
- Prevent re-sedation following reversal
- Identify possible candidates
- Select proper agents
- Discontinue the culprit drug(s)
- Use reversal agent(s)