Anesthesia, Analgesia, Anxiolysis, Amnesia, And so on…

1. Anesthesia, Analgesia, Anxiolysis, Amnesia, And so on… Ivy Pointer, M.D Pediatric Critical Care Fellow UNC Department of Anesthesiology

2. Overview • Role of sedation in critical care • Elements of sedation • Levels of sedation • Choosing a sedation plan • Choosing the right drug • Preventative medicine

3. Sedation in Critical Care • Medical illness • Post-operative care • Diagnostic imaging • Invasive procedures • Mechanical ventilation

4. Elements of Sedation • Anesthesia • Analgesia • Anxiolysis • Amnesia

5. Anesthesia • Definition • Loss of sensation & loss of consciousness • Examples (Intravenous anesthetics) • Etomidate • Ketamine • Propofol • Thiopental

6. Analgesia • Definition • Inability to sense pain • Examples • Non-sedating Analgesics • Lidocaine/L.M.X. 4 • Acetaminophen • NSAIDs (Ibuprofen, Ketorolac) • Sedating Analgesics • Narcotics (Fentanyl, Morphine, Oxycodone, Methadone) • Ketamine

7. Anxiolytics • Definition • Relief of apprehension, fear, and/or agitation • Examples • Benzodiazepines (Midazolam, Lorazepam, Diazepam) • Chloral Hydrate

8. Amnestics • Definition • Loss of memory, inability to recall events • Examples • Benzodiazepine • Ketamine

9. Awake Levels of Sedation Moderate Sedation Deep Sedation General Anesthesia

10. Moderate Sedation • Purposeful response to verbal stimulation • Airway patent • Spontaneous ventilation adequate • Cardiovascular function unaffected

11. Deep Sedation • Difficult to arouse • Purposeful response only to painful stimulation • Airway may be obstructed • Spontaneous ventilation may be impaired • Cardiovascular function usually unaffected

12. General Anesthesia • Loss of consciousness • Positive pressure ventilation • Cardiovascular function may be affected

13. Choosing a Sedation Plan • Remember mnemonic AMPLE!! • A llergies • Medications • Past Medical History • L ast Meal • E vents leading to sedation

14. Allergies • Drug allergies • Environmental allergies • Egg & soy allergy no Propofol • Contrast allergies

15. Medications • Knowing current medications & therapeutic interventions can help tailor your sedation plan… • Sedatives already being used • Vasoactive medications • Neuromuscular blockers • Respiratory medications • Hemofiltration/dialysis • And so on…

16. Past Medical History • Know current patient problem list and significant past medical/surgical history • Respiratory (hypoxia, pneumothorax) • Cardiovascular (hypotension, myocardial dysfunction) • Neurologic (increased ICP, seizure disorder) • Hepatic/Renal failure

17. Past Medical History • Past history of sedation • Medications used in the past • Prior adverse events with sedation • Ability to manage airway (Pierre Robin, croup, mediastinal mass, prior radiation, asthma) • Family history of problems with sedation

18. Past Medical History • ASA Physical Status Score • ASA I : normally healthy patient • ASA II: mild systemic disease • ASA III: severe systemic disease • ASA IV: severe systemic disease that is a constant threat to life • ASA V: moribund patient not expected to survive without operation

19. Physical Exam • Mallampati/Samsoon Classification • Class I: soft palate, uvula, pillars • Class II: soft palate, portion of uvula • Class III: soft palate, base of uvula • Class IV: hard palate only • Other predictors of difficult airway • Obesity with short neck • Reduced neck movement • Inability to protrude the lower teeth • Reduced mouth opening • Receding mandible • Thyromental distance of less than 3 fingers

20. Last Meal • Full stomach is a risk of aspiration during sedation!!! • NPO status • Last solid intake > 6 to 8 hours • Last opaque liquid/formula intake > 4 hours • Last clear liquid/breastmilk intake > 2 hours • These guidelines do not apply for patients with GI disturbances

21. Last Meal • Full stomachs include the following… • Any patient with material in their stomach • Food • Medications • Contrast • Charcoal • Blood • Any patient with delayed gastric emptying • Morbid obesity • Small bowel obstruction • Pyloric stenosis • GI dysmotility • And so on…

22. Events leading to sedation… • Know why your patient needs sedation!! • Is it safe to sedate your patient?? • What kind of sedation are you trying to achieve?? • Analgesia, anxiolysis, amnesia, or a combination • Anticipated duration of therapy

23. Choosing the Right Drug • There is no magic cocktail…all drugs have potential complications • Drugs to consider should fit your goals for sedation with minimum risk to the patient • Considerations when choosing a drug • Route of administration • Onset of action • Duration of action • Contraindications • Therapeutic advantages

24. Our favorite PICU drugs • Anesthetics: • Propofol, Ketamine, Pentobarbital • Analgesics: • Fentanyl, Morphine • Anxiolytics: • Midazolam, Lorazepam, Diazepam • Other: • Dexmedetomidine, Clonidine

25. Propofol • Onset: 30 sec • Duration: 3-10 min • Dose: 1 mg/kg • Infusion: 50-150 mcg/kg/min • Disadvantages: respiratory depression, hypotension, bradycardia, NO analgesia, metabolic acidosis with prolonged infusion

26. Ketamine • Onset: 30 sec (IV), 3-4 min (IM) • Duration: 5-10 min (IV), 12-25 min (IM) • Dose: 0.5-1 mg/kg (IV), 4-5 mg/kg (IM) • Infusion: 5-20 mcg/kg/min • Analgesia and amnesia • preserves upper airway tone and reflexes • Disadvantages: excess secretions, increased ICP, emergence reaction

27. Pentobarbital • Onset: 3-5 min (IV) • Duration: 15-45 min • Dose: 1-2 mg/kg • Disadvantages: NO reversal agent, no analgesia (enhances pain perception)

28. Fentanyl • Onset: 2-3 min • Duration: 30-60 min • Dose: 1 mcg/kg • 100x more potent than morphine • Available reversal agent • Naloxone • Disadvantages: no amnesia/ anxiolysis, “steel chest”

29. Morphine • Onset: 5-10 min (IV) • Duration: 4-6 hours • Dose: 0.05-0.1 mg/kg • Available reversal agent: • Naloxone • Disadvantages: no amnesia/ anxiolysis, histamine release

30. Midazolam (Versed) • Onset: 2-6 min • Duration: 45-60 min • Dose: 0.05-0.1 mg/kg • Available reversal agent • Flumazenil • Retrograde amnesia • Disadvantages: NO analgesia, paradoxical reactions

31. Diazepam (Valium) • Onset: 1-1.5 hours (oral) • Duration: variable but LONG (oral) • Dose: 0.1-0.8 mg/kg/day (oral) • Useful for tapering • Disadvantages: accumulation, long half-life, avoid rapid IV push

32. Lorazepam (Ativan) • Onset:15-30 min (IV) • Duration: 3-4 hours (up to 12 hrs) • Dose: 0.05-0.1 mg/kg • Disadvantages: mixed with propylene glycol • Anion gap metabolic acidosis, osmolar gap • Avoid infusions

33. Dexmedetomidine (Precedex) • IV alpha-2 agonist • 1700x more selective for alpha 2 • Onset: 15-30 min • Duration: 60-120 min • Dose: load with 0.5-1 mcg/kg • Infusion of 0.3 – 1.5 mcg/kg/hr • Disadvantages: bradycardia, only approved for 24 hr infusions

34. Clonidine • Centrally acting alpha-2 agonist • Onset: 30-60 min (oral) • Duration: 6-10 hours • Dose: 0.05 mg/day (oral) • Can convert to transdermal patch • Eases withdrawal & decreases anesthetic requirements

35. Contraindications • All drugs should be used judiciously!!! • Commonly seen relative contraindications and adverse effects • Ketamine  increased ICP, excess salivation, emergence reaction • Propofol  hypotension, acidosis • Dexmedetomidine  bradycardia, arrhythmia • Benzodiazepine  hypotension

36. Therapeutic Advantages • Not all side effects are harmful • Considerations for choice of drug • Ketamine  bronchodilator • Pentobarbital or Midazolam  anti-convulsant • Diazepam  muscle relaxation

37. Cases

38. Case #1 • An 8 year old known asthmatic is in the ED having received continuous albuterol nebs, steroids, and subcutaneous epinephrine. You check on him and find him unresponsive with a RR of 6 and very poor air movement. An RT runs in with a ABG showing pH 6.9, pCO2 190. What medications do you consider for intubation & sedation?

39. Case # 2 • A transport team has just arrived to pick up a 4 year old child with severe stridor. On exam she is alert, sitting in Mom’s lap & maintaining her sats, but has severe retractions with every breath and drooling. She appears frightened, and the paramedic asks you to order something to sedate her so that she can be strapped to the gurney. What is your response?

40. Case # 3 • You consult in the ED on a 7 year old who has presented with sore throat and noisy breathing. He has received 2 gm of chloral hydrate 1/2 hour before for an attempted CT scan of the neck. In the ED you find him in the back room with his mother, with a sat probe on his finger not attached to a monitor. He has retractions and poor air movement with every breath. What happened and what would you do?

41. Case # 4 • You are taking care of a 9 mo post-op cardiac patient who is intubated and requiring sedation. She initially had issues with heart block and required pacing but is now in a sinus rhythm of 110. She has been difficult to sedate with Fentanyl & Midazolam and the nurses ask you if you can add a 3rd agent. What agents would you want to avoid in this patient and what do you need to consider?

42. Case # 5 • You are called to the ED to see a 6 year old trauma patient who luckily has a normal head CT but unfortunately has a severely displaced tib-fib fracture. The orthopedic surgeons are gathering equipment to reduce and splint the fracture. What drugs do you think about using and what else do you consider?

43. Preventative Medicine is Key!! • Optimize your patient prior to sedation • Correct acidosis • Keep euvolemic • Know “AMPLE” • Anticipate difficulties and be prepared • Bag, mask, oxygen, +/- airway box • Suction • Normal saline/Lactated Ringer’s • Monitors – O2, CO2, CR monitor, BP • Titrate medications to effect…it is easier to give more drug than it is to remove it!!!

44. Summary • Many situations require sedation in the ICU • Components of sedation include anesthesia, analgesia, anxiolysis, & amnesia • There are several levels of sedation • Remember mnemonic “AMPLE” when evaluating a patient for sedation • Choosing the right drug involves knowing the goals of sedation alongside drug profile for sedatives • Always anticipate possible complications & be prepared to deal with them