Procedural Sedation in the Pre-Hospital Setting

1. Procedural Sedation in the Pre-Hospital Setting Antoinette Eng, MD Albany Medical Center December 20, 2006

2. EMS Procedural Sedation: Overview • Definition • Indications • Medications • Recent Research • Summary

3. Sedation Controlled reduction of environmental awareness

4. Sedation Dynamic

5. Moderate Sedation & Analgesia Anxiolysis Deep Sedation & Analgesia Anesthesia A Clinical Spectrum

6. Minimal Sedation • Drug-induced state • Impaired cognitive function & coordination • Responds to verbal commands • Ventilatory and cardiovascular functions intact Anxiolysis

7. Previously known as “conscious sedation” • Depression of consciousness • Respond purposefully to verbal commands alone or with light tactile stimulation • Ventilation and cardiovascular function intact Anxiolysis Moderate Sedation & Analgesia

8. Depression of consciousness • Not easily aroused, but responds purposefully after repeated or painful stimulation • May require airway and ventilatory support • Cardiovascular function maintained Anxiolysis Moderate Sedation & Analgesia Deep Sedation & Analgesia

9. Loss of consciousness • Patient cannot be aroused by painful stimuli • Requires airway and ventilatory support • Cardiovascular function may be impaired Anxiolysis Moderate Sedation & Analgesia Deep Sedation & Analgesia Anesthesia

10. Indications • Procedures Cardioversion Transcutaneous Pacing Pre/Post-Intubation Transport Extrication • Primary Treatment Anxiety Sympathomimetic Overdose Alcohol Withdrawal • Patient Restraint • Pain Management Adjunct Trauma Acute Abdomen ACS

11. Indications • Procedures Cardioversion Transcutaneous Pacing Pre/Post-Intubation Transport Extrication • Primary Treatment Anxiety Sympathomimetic Overdose Alcohol Withdrawal • Patient Restraint • Pain Management Adjunct Trauma Acute Abdomen ACS

13. Procedural Sedation: Medications • Benzodiazepines • Etomidate • Opiates • Nitrous Oxide

14. Benzodiazepines

15. Benzodiazepines • GABA is major inhibitory neurotransmitter in CNS • 3 types of receptors: GABA-A, GABA-B, GABA-C • GABA-A overwhelmingly numerically dominant receptor in CNS • BZO bind and allosterically modify receptor • Potentiate GABA response • Increase hyperpolarization • Increase neuronal inhibition at all levels of the neuraxis, including the spinal cord, hypothalamus, hippocampus, substantia nigra, cerebellar cortex, and cerebral cortex • Sedation, amnesia, muscle relaxation, anesthesia, anti-convulsant, anxiolytic

16. Midazolam • lipid soluble in blood • Rapid GI absorption, • Lipid solubility = prompt passage across blood-brain barrier, rapid redistribution and short duration of action • Large first-pass hepatic effect • Metabolism slowed in patients on cimetidine, erythromycin, calcium channel blockers, antifungal medications, fentanyl since they also use P450 cytochrome system • 1.0-2.5 mg IV • Onset 30-60 seconds • Time to Peak Effect 3-5 minutes • Duration of Sedation 15-80 minutes

17. Midazolam • Indications: • Sedation prior to cardioversion and intubation • Maintenance of sedation in mechanically ventilated patients • Pediatric seizure control

18. Midazolam Adults • Intubation adjunct: • 0.5-5mg IV/IM • may repeat every 5-10 minutes • max 10 mg • Status, cardioversion, pacing, inner ear problems, sedation, muscular spasms: • 0.5-2.5 mg IV, 5mg IM • may repeat every 5-10 mins • max 5mg

19. Midazolam Pediatric • Intubation: • 0.1-0.2 mg/kg • max 5 mg/dose, repeat PRN for sedation to max of 10 mg • Seizures: • 0.2-0.4 mg/kg IN/PR • IV/IM 0.05-0.2 mg/kg • repeat every 5 mins PRN • Sedation for painful procedures, cardioversion, pacing, muscular spasms, hyperdynamic drug ingestion/exposure: • 0.05-0.1 mg/kg IV/IM/IO • every 5-10 min (2-5 mins if IV) max 2.5 mg

20. Midazolam Side Effects • Ventilatory Depression caused by decrease in hypoxic drive • Effects greater than for Lorazepam and Diazepam • Exaggerated in presence of other opioids and CNS depressants, COPD, increasing age

21. Diazepam • Indications: • Seizures/status epilepticus • Sedation pre-cardioversion • Acute anxiety • Skeletal muscle relaxant • Alcohol withdrawal • Vertigo

22. Diazepam • Seizures: • 2-10 mg slow IV • 5-10 mg PR • max 20 mg • Sedation/cardioversion/pacing/muscle spasm/labyrinthitis/vertigo: • 2-5 mg slow IV every 5-10 mins • max 10mg

23. Midazolam vs Diazepam • More rapid onset • Greater amnesia • 2 to 3 times as potent • Twice the affinity for benzodiazepine receptor • Greater decrease in blood pressure and heart rate • Systemic vascular resistance • Less post-procedural sedation • Same time to complete recovery

24. Benzodiazepines

25. Benzodiazepines

26. Etomidate: Properties • Anesthetic • Non-narcotic sedative hypnotic • Increases GABA receptors, enhancing inhibitory neurotransmission • Reticular activating system depression • Short acting • Induces sedation & amnesia • No histamine release • Minimal cardiac & respiratory depressive effects

27. Etomidate: Adverse Effects • ? Decreased ICP • Nausea and vomiting • Myoclonus • Adrenocortical Suppression

28. Etomidate Indications: • Induction agent for intubation • Pre-medication for cardioversion

29. Etomidate • Adults & Pediatrics • Intubation: 0.3 mg/kg slow IV over 30-60 seconds, repeat as needed, maximum 0.6mg/kg • Short painful procedures: 0.15 mg/kg slow IV over 30-60 seconds

30. Etomidate vs Midazolam for Out-of-Hospital Intubation: A Prospective, Randomized TrialAnn Emerg Med. 47(6):525-30, 2006 Jun • Prospective, double blind, randomized • 55 Versed, 55 Etomidate • 75% success rate versed, 76% etomidate • No difference in success rates, incidence of hypotension, number of attempts, perceived difficulty

31. Opiates

32. Morphine • Central nervous system depressant • Acts at mu receptors above and at spinal cord • Decrease cardiac preload/afterload • Decreases myocardial oxygen demand • Releases histamine  can cause hypotension

33. Morphine • Dose: 0.05-0.1 mg/kg IV • Peak: 10-30 minutes • Duration: 2-4 hours

34. Morphine • Adverse Reactions & Side Effects • CNS: Euphoria, sedation, respiratory depression • Cardiovascular: bradycardia, hypotension • GI: decreased motility, nausea, vomiting • GU: urinary retention • Respiratory: bronchoconstriction, antitussive

35. Fentanyl • Synthetic opioid derivative • 100x potency of morphine • Highly lipid soluble • Stored in adipose tissue to create a “reservoir” • Low complication rate • Doesn’t release histamine, rarely produces hypotension

36. Fentanyl • Dose: 1 mcg/kg IV • Onset: Fast • Peak: 2.5-10 minutes • Duration: 30-90 minutes

37. Fentanyl • Respiratory depression with alcohol or versed • Chest wall rigidity • dose dependent • not reliably antagonized by naloxone

38. Nitrous Oxide

39. Nitrous Oxide • Colorless gas • Mixed with 50% oxygen and inhaled • Self-administered by patient • Mild intoxicant, potent analgesic • Disspiates within 2-5 minutes after stopping

40. Nitrous Oxide • Adverse Reactions • Light-headed • Confusion • Drowsiness • Nausea/vomiting

41. Nitrous Oxide • Contraindicated: • Altered state of consciousness • Head injury, alcohol ingestion, drug OD • COPD • Pneumothorax • Decompression sickness • Air embolus • Abdominal pain with distension • Pregnancy, except during delivery • Unable to self-administer

42. Nitrous Oxide • Considerations • Currently not on REMO protocol, but a good drug to know about • Heavier than air, can accumulate at ambulance floor and affect EMS personnel

43. Patient Restraint • No standing orders • Available through Medical Control: • Age < 70: Haloperidol 5mg mixed with Midazolam 2mg IM • Age > 70: Haloperidol 5mg IM • Repeat

44. Patient Restraint In 1998 California survey of 490 EMS providers: • 61% recounted assault on the job • 25% reported injury • 37% of injured required medical attention • 95% recounted restraining patient “Exposure of prehospital care providers to violence.” Prehospital Emergency Care. 2(2):127-31, 1998 Apr-Jun.

45. Dangers to Patients • “Positional Asphyxia During Law Enforcement Transport.” • Am Jrnl of Forensic Med and Path. Reay DR. 13(2):90-7, 1992. • “Met Acidosis in Restraint-Associated Cardiac Arrest: A Case Series.” • Acad Emerg Med. Hick, et al. 6(3):239-44, 1999. • “Sudden Death in Individuals in Hobble Restraints During Paramedic Transport.” • Ann of Emerg Med. Stratton SJ, et al. 25(5):710-12, May 1995.

46. Patient Restraint • Indications: • Patients at risk of causing physical harm to emergency responders, the public, and/or themselves • Considerations: • Cannot be transported face down • If in police custody with handcuffs on, must beaccompanied by police officer in ambulance to hospital • EMS may only apply “soft restraints”

47. Haldol • Dopamine blockade in mesocortex and limbic system inhibits psychoses • Extrapyramidal effects (akathisia, dystonia, pseudoparkinsonism) due to dopamine blockade in niagrostriatal pathways • Sedative for psychomotor agitation • Minor anticholinergic and antihistaminic actions rarely cardiovascular, anticholinergic effects • May cause QT prolongation, lower seizure thresholds

48. Haldol • Indications: • Acute and chronic psychoses • Agitation, aggression • Contraindications: • Parkinson’s • Seizure • Cocaine overdose • Alcoholism • Severe mental/CNS depression • thyrotoxicosis

49. Haldol • Dosage 5-10mg IM

50. Summary • Sedation is a dynamic spectrum • Main EMS uses: • Procedures • Restraint • Primary Treatment • Pain management adjunct