10/20/2009. Ann Emerg Med, Feb 2005

Transcription

1 Critical Decisions in ED Procedural Sedation and Analgesia Why is ED procedural sedation important? Susan Lambe, MD Assistant Clinical Professor UCSF Department of Emergency Medicine Why is procedural sedation important? The greatest evil is physical pain. -Saint Augustine ( AD) Philospher and theologian Why is procedural sedation important? House: If I'm in a buttload of pain, I need a buttload of pills. (Television) House M.D.,

2 Physician Why is procedural sedation important? Control of pain, anxiety and motion to optimize conditions for procedure Patient Provide decreased awareness and memory loss for the patient to tolerate the procedure Four Critical Decisions 1. Patient selection 2. Pre-sedation preparation 3. Choosing the best agent 4. Understanding advances in procedural sedation Decision #1: Is my patient a candidate for procedural sedation? 1. Patient selection 2. Pre-Sedation preparation 3. Choosing the best agent 4. Advances in procedural sedation 2

3 3 Components Patient Selection NPO status Targeted Pre-sedation History Targeted Pre-sedation Physical Patient Selection - NPO NPO guidelines ASA guidelines: 2 hours for clear liquids 8 hours for solids NPO Guidelines Patient Selection Application of ASA guidelines to ED patients controversial Consensus guidelines, not evidence-based Extrapolated from OR patients ED patients are different Generally healthier Lower doses of agents Airway is not manipulated (no intubation/extubation) ACEP Guidelines Patient Selection Recent food intake is not a contraindication for administering procedural sedation and analgesia, but should be considered in choosing the timing and target level of sedation Ann Emerg Med, Feb

4 Patient Selection NPO Guidelines Prospective pediatric case series, ED sedation (n=1,014) 509 (56%) did not meet ASA fasting guidelines Adverse events occurred 35/509 (6.9%) non-fasted patients 32/396 (8.1%) fasted patients No sig difference in median fasting duration between patients with and without emesis/adverse events Agarwal, et al, Ann Emerg Med, 2003 Patient Selection NPO Critical Message: Use common sense! If feasible, make pts NPO according to ASA guidelines If not feasible or pt has emergent indication, data suggests sedation may be safe even when not fasted to ASA guidelines Targeted History Patient Selection Alcohol/Drug History Drugs given in ED PMHx Meds Allergies Prior anesthesia or sedation History of difficult intubation Targeted Exam Mental status HEENT Oropharynx Jaw mobility Neck mobility Heart Lungs Patient Selection 4

5 Patient Selection ASA Status Most ED sedation done on ASA Class 1 healthy patients ASA Class 2 mild systemic disease Mild asthma Seizures controlled Mild DM controlled Critical Decision #2: How do I prepare? 1. Patient selection 2. Pre-Sedation preparation 3. Choosing the best agent 4. Understanding advances Be Prepared: Consent Critical Decision #2: Be Prepared! 5

6 Consent Be Prepared! Risks Benefits Limitations Potential Side Effects Alternatives Verbal or written consent obtained Personnel Be Prepared! Two experienced providers One monitoring patient s ABCs One performing procedure Most adverse events occur in first 1-5 minutes, or end of procedure when stimulus is removed Be Prepared! Continuous Monitoring Capnography study Be Prepared! 60 sedation encounters 20 acute respiratory events Capnography detected 14/20 acute respiratory events BEFORE desaturation or clinically observed hypoventilation Pulseoximetry Capnography ECG/BP Monitoring Burton, et al, Acad Emerg Med,

7 Be Prepared! Be Prepared to intubate! IV access Oxygen Airway equipment/suction Be Prepared! Critical Decision #3: How do I select the best agent? 1. Patient selection 2. Pre-Sedation preparation 3. Choosing the best agent 4. Understanding advances 7

8 Selecting the best agent Critical Decision #3: How do I select the best agent? Midazolam (Benzodiazepine) Fentanyl (Opiate) Methohexital (Barbiturate) Propofol (Isopropylphenol) Etomidate (Imidazole) Ketamine (Cyclohexanone) Midazolam Old school Midazolam (Versed) Midazolam Shortest acting benzo Sedation/amnesia/anxiolysis No analgesia Adverse effects Hypoventilation Hypotension Paradoxical hyperactivity 8

9 Midazolam Onset of action iv 2-3 minutes Duration minutes Dose IV 0.1 mg/kg Can be given im, po, intranasal and pr erratic absorption delayed onset, dose is difficult to titrate Careful iv titration of midazolam is best Fentanyl Fentanyl Short-acting opiod analgesic No anxiolytic or amnestic properties Must combine with a sedative agent Fentanyl has no histamine release Less nausea/vomiting Less hypotension Dose 1-2 mcg/kg iv Onset <30 seconds Fentanyl Peak effect 2-3 minutes Duration minutes 9

10 Fentanyl Methohexital Adverse effects Respiratory depression Pruritis Rarely rigid chest syndrome (dose >15 mcg/kg) Reverse with naloxone Methohexital (Brevital) Ultra-short acting barbiturate Sedation/amnesia/anxiolysis No analgesic properties Can give iv, pr Methohexital Dose 0.75 to 1 mg/kg iv Onset 5-15 seconds Offset <10 minutes Outstanding for short procedures 10

11 Disadvantages Methohexital Transient, self limited Respiratory depression Hypotension No reversal agent Relatively contraindicated for patients with Bronchospasm Seizure Disorder Milk of Amnesia Propofol Propofol Ultra-short acting sedative hypnotic No significant analgesia Extremely rapid onset and recovery Inherent anti-emetic & euphoric effect 11

12 Propofol Onset <60sec Recovery 5-15 min Initial bolus 0.1 mg/kg provider re-doses at 0.05 mg/kg up to every 60 seconds. Use lower doses In the elderly, because volume of distribution decreases with age If using with opiates Disadvantages Propofol Transient, self limited Hypotension Respiratory depression Pain at injection site Contraindicated in patients with egg/soy allergies Etomidate Etomidate Ultra-short acting sedative hypnotic agent Sedation, anxiolysis and amnesia No analgesia Extremely rapid onset and recovery Unique because does not cause hypotension 12

13 Etomidate Dose: mg/kg iv, repeat if inadequate response Onset 5-30 seconds Duration 5-15 minutes Etomidate disadvantages Myoclonus (20-45%) Pain at injection site (50%) 2/2 propylene glycol Rare Emergence delirium Transient adrenal suppression Etomidate vs. Propofol Propofol vs. Etomidate Etomidate vs. Propofol RCT (n=214) Etomidate Less hypotension 3.8% (etomidate) vs. 7.9% (propofol) More myoclonus 20% (etomidate) vs. 1.8% (propofol) Lower rate of procedure success 93/105 successful with etomidate 106/109 successful with propofol Miner, et al, Ann Emerg Med, 2007 Propofol Hypotension, transient self-limitedlimited No myoclonus Generally better, especially if lack of movement is a priority Etomidate Maintains hemodynamics Causes myoclonus Better if maintaining hemodynamics is a priority 13

14 Ketamine Ketamine Ketamine A phencyclidine (PCP) derivative Ketamine Pharmacology Ketamine binds phencyclidine receptor in the NMDA channel inhibits glutamate activation of the channel in a noncompetitive way Sympathomimetic Inhibits catecholamine re-uptake ketamine phencyclidine 14

15 Ketamine is unique Dissociative anesthetic blocks communication between the thalamic and limbic regions of the brain prevents brain from processing external stimuli Preserves cardiopulmonary stability No dose-response continuum Emergence phenomenon Ketamine Two main pharmacologic effects Neurologic - depresses the limbic system Anesthesia, analgesia, amnesia Hallucinations Cardiopulmonary Hypertension Tachycardia Bronchodilation Thought to increase intracranial pressure and intraocular pressure Ketamine Dose IV 1-2 mg/kg IM 4 mg/kg Onset IV 1-5 min, over 60 sec IM 5-10 min Duration IV 5-15 min IM min Ketamine Adverse effects (n=1,022) Increased salivation Post-procedure vomiting (12%) Respiratory depression (0.3%) Associated with rapid iv push Green, Ann Emerg Med,

16 Adverse effects (cont.) Ketamine Laryngospasm (0.4%) Rare, Self-limitedlimited Associated with procedures that stimulate the larynx Green, Ann Emerg Med, 1998 Adverse effects (cont.) Emergence phenomenon Ketamine Nightmares, hallucinations Children (1.6%) Adults variable (5-30%) Risk factors Age >16 Larger dose More rapid administration Mitigated by Quiet room Benzos Ketamine Contraindications Absolute - risks always outweigh benefits Age <3 months Anecdotal evidence Airway obstruction, laryngospasm, apnea Psychosis Exacerbates established psychosis Ketamine Contraindications Relative Age <12 months Procedures on posterior pharynx Abnormal tracheal/laryngeal anatomy URI/pulmonary disease CAD/CHF/HTN 16

17 Ketamine Contraindications (cont.) Relative CNS mass, structural abnormality, hydrocephalous Open globe/glaucoma Porphyria/thyroid dz Ketamine Summary Extremely safe, especially in children Very useful for longer procedures if given IM Be familiar with pharmacology and contraindications Choosing the best agent Become expert with a few agents Midazolam (Benzodiazepine) Fentanyl (Opiate) Methohexital (Barbiturate) Propofol (Isopropylphenol) Etomidate (Imidazole) Ketamine (Cyclohexanone) Critical Decision #4: 1. Patient selection 2. Pre-Sedation preparation 3. Choosing the best agent 4. Understanding advances in procedural sedation 17

18 Critical Decision #4: Understanding Advances in Procedural Sedation Ketamine + Propofol = Ketofol Reducing myoclonus from etomidate Ketamine for head injury Ketofol = propofol + ketamine Add subdissociative dose ketamine to propofol Agents are synergistic Ketamine s sympathomimetic effects should mitigate propofol-induced hypotension Propofol should counteract nausea and psychic effect of ketamine Ketofol: Two small ED studies One descriptive study in ED patients (n=114) 1:1 mixture of ketamine (10 mg/ml) and propofol (10mg/ml) was titrated iv Median dose 0.75mg/kg of propofol, 0.75 mg/kg iv of ketamine subdissociative dose for ketamine Willman, Ann Emerg Med,

19 Ketofol adverse events (n=114) 4 required additional agents 3 had transient hypoxia 1 required BVM 4 required airway repositioning 3 had emergence reaction 1 required midazolam Ketofol RCT Propofol-Ketamine vs. Propofol-Fentanyl (n=63) Investigators randomized to Ketamine 0.3 mg/kg iv OR Fentanyl 1.5 mcg/kg iv Waited 2 minutes, then infused propofol, titrated to effect Fentanyl group had 5.1 times odds of having an intrasedation event compared with ketamine group Messenger, Acad Emerg Med, 2008 Ketofol: Pediatric IR procedures Propofol/fentanyl vs. propofol/fentanyl/ketamine Used subdissociative dose of ketamine (0.5 mg/kg) Less desaturation in children who received ketamine (10% vs. 30%) Ketamine + propofol = Ketofol Very promising Few small ED studies Watch for more data in the ED literature Erden, et al, Pediatr Anesthesia,

20 Etomidate - reducing myoclonus High dose etomidate (0.3 mg/kg) vs. pentobarb (4 mg/kg) Etomidate had fewer adverse events (0.9% vs. 4.5%) Baxter, Pediatr Emerg Care, 2007 (n=842 at 22 institutions) Midazolam (0.015 mg/kg) 90 sec before etomidate Midazolam (0.015 mg/kg) 90 sec before etomidate Myoclonus in 10% vs. 50% in etomidate only group Myoclonus in 10% vs. 50% in etomidate only group Huter, Anesth Analg, 2007 (n=40) Ketamine Safe in head injury? All the textbooks tell you not to use it Tintanelli, Rosen In theory, should be protective Unlike other sedating agents, ketamine maintains BP/HR, desirable in head injury Antagonism of NMDA receptor protects from cellular mechanisms of neuronal death in vitro Ketamine Safe in head injury? Case against ketamine for head injury 3 early studies circa 1972 Found increased CSF pressure measured at the lumbar spine, and lateral ventricle after ketamine Small numbers Many with abnormal CSF pathways (e.g., shunts, anatomic abnormalities) Case for Ketamine for head injury Recent, small studies in intubated ICU patients suggest ketamine may be protective in patients with head injury 20

21 Ketamine Adult ICU patients with TBI Ketamine vs. sufentanil in SAH/TBI (n=24) No difference in ICP/CPP Schmittner, 2007 Ketamine/midazolam vs. sufentanil/midazolam in severe TBI (n=33) No difference in ICP/CPP Bourgin, 2005 Small numbers, not in ED patients Ketamine in pediatric TBI Gave iv ketamine to intubated children (age 1-16) 16) with severe TBI/ICH 82 ketamine administrations in 30 children Dose mg/kg Observed x 10 minutes Measured ICP with ventriculostomy ICP decreased by 30% post-ketamine Bar-Joseph, J. Neurosurg Pediatr, 2009 Ketamine Safe in head injury? No large studies yet in ED literature Few small studies in ICU patients suggest ketamine may not increase ICP as previously thought Stay tuned! Watch for ED studies Critical Points Use a targeted H&P to determine if your patient is a candidate Be prepared Have a dedicated airway provider Be prepared to intubate Choosing the best agent Get comfortable with a few key agents Stay up to date with the advances in sedation 21

22 Case 1 Audience Response Questions 4 yo F presents after fall from monkey bars with forehead contusion and angulated R forearm fracture. You are asked to provide sedation for reduction. Which agent do you choose? What do you want? Which agent? Short acting Skeletal muscle relaxation 1. Fentanyl/Midazolam 2. Ketamine 3. Propofol 4. Etomidate 5. Methohexital 25% 38% 24% 10% 4%

23 Case 2 Which agent? 56 yo with no PMHx with acute onset palpitations 1 hour ago. Cardiac monitor shows atrial fibrillation with HR=160, BP 85/50. EKG confirms atrial fibrillation. You decide to use electrical cardioversion. Which agent will you use for the procedure? 1. Methohexital 2. Propofol 3. Etomidate 4. Ketamine 5. Midazolam 32% 45% 12% 7% 4% Case 3 Which agent? 2 yo M with complex facial laceration. Needs sedation for repair. Which agent should you use? 1. Fentanyl/Midazolam 2. Ketamine 3. Propofol 4. Etomidate 5. Methohexital 100% 0% 0% 0% 0%

24 Thank you! 24