681 likes | 1.36k Views
Emergency Rapid Sequence Intubation: A “How and When To” Guide. Pat Melanson, MD, FRCPC Department of Emergency Medicine Division of Critical Care Medicine Royal Victoria Hospital. Rapid Sequence Intubation : Definition.
E N D
Emergency Rapid Sequence Intubation:A “How and When To” Guide Pat Melanson, MD, FRCPC Department of Emergency Medicine Division of Critical Care Medicine Royal Victoria Hospital
Rapid Sequence Intubation :Definition • The near simultaneous administration of a sedative-hypnotic agent and a neuromuscular blocker in the presence of continuous cricoid pressure to facilitate endotracheal intubation and minimize risk of aspiration • modifications are made depending upon the clinical scenario
A Brief History of Emergency RSI • intubation of the newly/nearly dead (prehistoric) • techniques adapted from anesthetists in Case Room and “crash” full-stomach induction's (exploration) • rapid dissemination of RSI teaching to emergency physicians (proselytism) • evidence-based research supporting safety and advantages of emergency RSI (enlightenment) • increasingly sophisticated techniques and methodology critically evaluated (postmodern)
Intubation Dilemmas: • Intubate Awake or Asleep • Oral or Nasal • Laryngoscopy or Blind Intubation • To Paralyze or Not
Oral Intubation Without Drugs • Reserved for the completely unconscious, unresponsive, pulseless and apneic • Arrest situations only • The “ CRASH AIRWAY”
Oral Intubation with Sedation • proponents argue use of BZ or opioids • improves airway access • decreases patient resistance • avoids risks of NMB • Generally obtunds patient to point of loss of protective reflexes and respiratory drive • lower success rate, higher complications compared with RSI
Oral Intubation with Sedation • “ In general, the technique of administering a potent sedative agent to obtund the patient’s responses and permit intubation in the absence of NMB is hazardous and to be discouraged… is not an appropriate alternative to properly conducted RSI and affords neither the success rate or the minimal complication rate of RSI.” • RM Walls, page 4, Chapter 1, Rosen
Oral Intubation with Sedation • “ The avoidance of NMB actually creates a more hazardous situation for the patient and this practice should no longer be considered an appropriate method for emergency department ET intubation.” • RM Walls, page 8, Chapter 1, Rosen
Oral Intubation with Sedation:Use for the Anticipated Difficult Airway • if time permits • topical anesthesia • careful titrated sedation • avoid obtundation • ‘Awake” intubation technique
Blind Nasal Intubation • success rates 65 - 80 % in most series • high complication rates • epistaxis • pharyngeal/ esophageal perforations • increased incidence of O2 desats • Considered second line approach only • reserved for when RSI contraindicated • The “ DIFFICULT AIRWAY”
Approach to Airway Management: Algorithms • Is intubation indicated ? • Is this a Crash Airway situation ? • Is this a potentially Difficult Airway? • Difficult laryngoscopy ? • Difficult Bag -Mask Ventilation? • Is RSI appropriate ? • Is this a Failed Airway?
Emergency Airway Concerns • “full” stomach • minimal respiratory reserve • hemodynamic instability • acute myocardial ischemia • increased intracranial pressure • C-spine injury • The “Difficult” Airway • Laryngoscopy • bag-mask difficulty
Advantages of RSI • facilitates and expedites endotracheal intubation • increased success rate • decreased time to intubation • minimizes trauma during laryngoscopy • minimizes hypoxia and hypercapnia • minimizes risk of aspiration • minimizes hemodynamic effects of intubation
Disadvantages of RSI • operator assumes complete responsibility for oxygenation, ventilation and airway patency • irreversible commitment • (burnt bridges) • adverse effects of medications • ?? increases surgical airway rate • no evidence
Rapid Sequence Intubation: Principles • Emergency intubation is indicated • The patient has a “full” stomach • Intubation is predicted to be successful • If intubation fails, ventilation is predicted to be successful • Consists of a series of planned discrete steps
Principles of RSI • Competing demands: • Minimizing risk of aspiration vs. risk of hypoxia • Preoxygenation: • ideally avoid BMV-PPV to minimize aspiration • adequate N2 washout (5 min 100% O2 ) gives oxygen reservoir providing several minutes of O2 supply despite apnea • 4 assisted PPV breaths prior to paralysis • pulse oximetry essential • ANTICIPATE the O2 trend!
Principles of RSI (cont) • Minimizing gastric distention • avoidance of BMV-PPV • cricoid pressure • caudal to thyroid cartilage • complete ring esophageal occlusion • release if vomiting occurs • maintain until ETT position confirmed • minimize peak pressures if BMV-PPV • immediate ID of esophageal intubation
time 0:00 2:00 2:15 3:00 3:20 5:00 100% O2, iv access, monitor, oximetry assemble equipment, meds and team thiopental 3mg/kg iv succinylcholine 1.5mg/kg iv cricoid pressure with LOC; no bagging laryngoscopy after fasciculations tube position confirmed and secured positive pressure ventilation begins To CT/lavage/OR/etc. O2 sat 100% throughout Typical Emergency RSI: Time Course
Drugs used for RSI: Overview • Essential: • Paralytic • Sedative/ Induction agent • Optional: • Defasciculant • Modulators of hemodynamics/ICP/etc.
Emergency RSI: Selecting the Patient Is RSI contraindicated? • Absolute: • Cardiopulmonary arrest present/imminent • Operator inexperience • Relative: • Anticipated technical difficulties with laryngoscopy and/or intubation • Anticipated difficulty with BVM
Emergency RSI: Selecting the Paralytic Neuromuscular blocking agents • Depolarizing: • Succinylcholine • Non-depolarizing: • Vecuronium • Rocuronium
Emergency RSI: Selecting the Paralytic • Is succinylcholine contraindicated? NO: choose succinylcholine YES: choose rocuronium (or vecuronium) • If using SUX, is atropine needed? atropine 0.02mg/kg (.15mg-.5mg) 2min before • If using SUX, is a defasciculant desired? 10% dose of non-depolarizing agent 2 min prior
Succinylcholine ( Anectine) • dose: 1.5 mg/kg • onset : 45 - 60 seconds • duration : 6 to 10 min (3 to 15) • disadvantages : • ACh analog - bradycardia • fasciculations • hyperkalemia ( K+ release) • malignant hyperthermia
Succinylcholine : Contraindications • Hyperkalemia - renal failure • Active neuromuscular disease with functional denervation • ( 6 days to 6 months) • Extensive burns, crush injuries • Malignant hyperthermia • Pseudocholinesterase deficiency • Organophosphate poisoning
Succinylcholine : Complications • Inability to secure airway • Increased vagal tone ( second dose ) • Histamine release ( rare ) • Increased ICP/ IOP/ gastric pressure • Myalgias • Hyperkalemia with burns, NM disease • Malignant hyperthermia
Vecuronium ( Norcuron ) • dose : 0.1 - 0.2 mg/kg • action : 120 secs to 60 minutes • “prime” with 1/10 dose 2 min prior • onset in 90 secs • advantages : • non-depolarizing • neutral hemodynamics • hepatic clearance
Rocuronium ( Zemuron ) • dose : 0.6 - 1.2 mg/kg • onset : 60 -90 secs • advantages : • almost as rapid as SUX • disadvantages • less rapid in elderly • long duration
Emergency RSI: Selecting the Sedative ? Thiopental Ketamine Midazolam Propofol Etomidate (nothing) ? ? ?
Thiopental ( Pentothal ) • dose : 1- 5 mg/kg • action : 20 sec to 5 minutes • advantages • ultrafast, short duration • neuroprotective, anticonvulsant • familiar • disadvantages • hypotension ( myocardial depression, vd) • ultrashort duration ( 3 - 5 minutes ) • demyelination in porphyria • chemical endarteritis, thrombosis
Midazolam ( Versed ) • dose : 0.1 - 0.4 mg/kg • action : 2 min to 120 minutes • advantages: • wide therapeutic index • amnesia • disadvantages • variable dose response • slower onset • suboptimal effect at lower doses • negative inotrope, vasodilation
Ketamine ( Ketalar ) • dose : 1 - 2 mg/kg • action : 30 secs to 15 minutes • advantages : • bronchodilation • supports BP • disadvantages : • increases ICP and IOP • salivation • emergence reactions
Propofol ( Diprivan ) • dose : 0.5 - 2.5 mg/kg (20-40mg q10 s) • action : 20 sec to 5 minutes • advantages : • ultrarapid • neuroprotective • disadvantages • hypotension, bradycardia • ultrashort duration
Etomidate ( Amidate ) • dose ; 0.3 mg/kg • action : 1 minute to 10 minutes • advantages : • hemodynamically neutral • neuroprotective • disadvantages : • unfamiliar • vomiting • cortisol suppression
Emergency RSI: Selecting the Sedative Identify Primary Concern: • Hemodynamics: fentanyl, ketamine, etomidate • Neuroprotection: thiopental, propofol (midazolam) • Bronchodilation: ketamine • Speed: thiopental, propofol (ketamine)
Emergency RSI: Selecting the Sedative Identify any Secondary Concerns: • Hemodynamics: beware thiopental, propofol (midazolam) • Neuroprotection: avoid ketamine (??) • Speed: beware midazolam • Patient given naloxone: avoid fentanyl • Specific contraindications (e.g. porphyria): avoid drug
The “Intubation Reflex “ • Catecholamine release in response to laryngeal manipulation • Tachycardia, hypertension, raised ICP • Attenuated by beta-blockers, fentanyl • ICP rise possibly attenuated by lidocaine • Midazolam and thiopental have no effect
Emergency RSI: Selecting optional medications • Increased ICP: Lidocaine • Bronchospasm : Lidocaine • Tachycardia harmful: fentanyl (esmolol) 3 min before • atropine if child receiving Sux • defasciculant • “priming” dose of neuromuscular blocking agent • topical/regional anesthetics
Emergency RSI Checklist: Flight planning • Move patient to resuscitation suite • Assemble personnel • 100% O2 • Patient too unstable for RSI => intubate ASAP • Inadequate ventilation/sat <90% => BMV • Select drugs and doses, delegate “Drug Nurse” • Cardiac monitor, BP cuff, O2 sat continuously • IV running in limb contralateral to BP cuff • Cleared to taxi
Emergency RSI Checklist: Taxiing • C-Spine? OK: pillow/folded sheet under head ?: designate assistant in-line stabilization • Check ETT and lubricate (+/- stylet) • Check laryngoscope (and other airway device prn) • Yankauer suction on and under mattress (to right) • Final neuro assessment (AVPU, posturing, pupils) • Baseline HR, BP, O2 sat • Review drugs, doses and sequence with Drug Nurse • Cleared for take-off
0:00 3:00 3:15 4:00 4:30 5:00-15:00 administer optional drugs administer sedative administer paralytic cricoid pressure with loss of ciliary reflex BMV if hypercapnia deleterious/sat <90% laryngoscopy once fully relaxed BURP to visualize larynx Confirm ETT placement and secure Ventilator settings Treat fluctuations in VS as indicated CXR Emergency RSI Checklist: Take-off time (mm:ss)
Rapid Sequence Intubation :Procedure • Pre-intubation assessment • Pre-oxygenate • Prepare • Premedicate • Paralyze with Induction • Pressure on cricoid • Place the tube • Post intubation assessment
Pre-oxygenate ( Time - 5 Minutes) • 100 % oxygen for 5 minutes • 4 conscious deep breaths of 100 % O2 • Fill FRC with reservoir of 100 % O2 • Allows 3 to 5 minutes of apnea • Essential to allow avoidance of bagging • If necessary bag with cricoid pressure
Preparation ( Time - 5 Minutes ) • ETT, stylet, blades, suction, BVM • Cardiac monitor, pulse oximeter, ETCO2 • One ( preferably two ) iv lines • Drugs • Difficult airway kit including cric kit • Patient positioning
Pre-treatment/ Prime ( Time - 2 Minutes ) • Lidocaine 1.5 mg/kg iv • Defasciculating dose of non-depolarizing NMB • Fentanyl 3- 5 mcg/kg • Atropine 0.02 mg/kg • ( The above agents are optional and given if there is a specific indication and time permits)
Induction agent • Thiopental 3 - 5 mg/kg • Midazolam 0.1 - 0.4mg/kg • Ketamine 1.5 - 2.0 mg/kg • Propafol 0.5 - 2.0 mg/kg • Etomidate 0.2 - 0.3 mg/kg
Paralyze ( Time Zero ) • Succinylcholine 1.5 mg/kg iv • Allow 45 - 60 seconds for complete muscle relaxation • Alternatives • Vecuromium 0.1 - 0.2 mg/kg • Rocuronium 0.6 - 1.2 mg/kg
Pressure • Sellick maneuver • initiate upon loss of consciousness • continue until ETT balloon inflation • release if active vomiting
Place the Tube ( Time Zero + 45 Secs ) • Wait for optimal paralysis • Confirm tube placement with ETCO2
Post-intubation Hypotension • Loss of sympathetic drive • Myocardial infarction • Tension pneumothorax • Auto-peep
Difficult Airway Kit • Multiple blades and ETTs • ETT guides ( stylets, bougé, light wand) • Emergency nonsurgical ventilation ( LMA, Combitube, TTJV ) • Emergency surgical airway access ( cricothyroidotomy kit, cricotomes ) • ETT placement verification • Fiberoptic and retrograde intubation