Selected Controversies in Selected Controversies in Pre-Hospital Emergency CarePre-Hospital Emergency Care

Moritz Haager PGY-2Moritz Haager PGY-2Dr. Ian WishartDr. Ian WishartApril 24, 2003April 24, 2003

ObjectivesObjectives Does pre-hospital intubation improve Does pre-hospital intubation improve

patient outcomes?patient outcomes? Are ALS trained crews superior to Are ALS trained crews superior to

BLS only systems?BLS only systems? Are current fluid resuscitation Are current fluid resuscitation

protocols appropriate?protocols appropriate?

More is Better. Right?More is Better. Right? Development of ALS-capable EMS Development of ALS-capable EMS

systems based on assumption that systems based on assumption that earlier provision of advanced earlier provision of advanced interventions will improve outcomesinterventions will improve outcomes

““The entire basis of prehospital care The entire basis of prehospital care is directed toward straightforward is directed toward straightforward treatments that make sense based treatments that make sense based on probable cause of early death”on probable cause of early death”

Hoyt. Ann Surg. 2003; 237: 161-2Hoyt. Ann Surg. 2003; 237: 161-2

Multicenter Canadian Study of Multicenter Canadian Study of Prehospital Trauma CarePrehospital Trauma Care

Prospective cohort study of EMS systems Prospective cohort study of EMS systems in 3 major trauma centresin 3 major trauma centres

9045 pts treated by BLS-EMT, PMD-ALS, or 9045 pts treated by BLS-EMT, PMD-ALS, or MD-ALSMD-ALS• 36% inc in odds of dying for MD-ALS36% inc in odds of dying for MD-ALS• 21% inc in odds of dying for ALS vs BLS21% inc in odds of dying for ALS vs BLS• Differences significant even when stratified by Differences significant even when stratified by

Injury Severity ScoreInjury Severity Score Conclude that EMS-ALS crews have no Conclude that EMS-ALS crews have no

benefit in trauma victims in urban centersbenefit in trauma victims in urban centers

Multicenter Canadian Study of Multicenter Canadian Study of Prehospital Trauma CarePrehospital Trauma Care

LimitationsLimitations• MD’s & PMD-ALS crews saw sicker ptsMD’s & PMD-ALS crews saw sicker pts• Significant differences in patient Significant differences in patient

population b/w cities involvedpopulation b/w cities involved• Not a randomized studyNot a randomized study

The BottomlineThe Bottomline None of the ALS interventions has None of the ALS interventions has

been shown to be beneficial in been shown to be beneficial in sufficiently rigorous studiessufficiently rigorous studies

Some (e.g. PASG, IV fluids, pediatric Some (e.g. PASG, IV fluids, pediatric RSI) appear to worsen mortality RSI) appear to worsen mortality

Lots of money, training, and ongoing Lots of money, training, and ongoing experience required to aquire and experience required to aquire and maintain skillsmaintain skills

The BottomlineThe Bottomline ““it will be difficult for us to accept it will be difficult for us to accept

since we have so much invested in since we have so much invested in training ALS skills & because of the training ALS skills & because of the intuitive nature of these practices for intuitive nature of these practices for improving outcome”improving outcome”

Hoyt. Ann Surg. 2003; 237: 161-2Hoyt. Ann Surg. 2003; 237: 161-2

AIRWAYAIRWAY 1950’s – landmark studies by Elam & 1950’s – landmark studies by Elam &

Safar demonstrate efficacy of rescue Safar demonstrate efficacy of rescue breathing in maintaining Obreathing in maintaining O22 sats @ sats @ 90%90%

Methods for Airway ControlMethods for Airway Control BVMBVM LMA / intubating LMALMA / intubating LMA Combi-tubeCombi-tube ETTETT

• Definitive, but also most complicated Definitive, but also most complicated Surgical airwaySurgical airway Where does the balance of risking Where does the balance of risking

aspiration vs. failed airway capture lie? aspiration vs. failed airway capture lie? Which method is most expedient?Which method is most expedient?

Evaluating Airway MethodsEvaluating Airway Methods

Variables to considerVariables to consider• Time spent capturing airwayTime spent capturing airway• Success rate of capturing airwaySuccess rate of capturing airway• Complications particular to that methodComplications particular to that method

AspirationAspiration Failed airwayFailed airway Surgical airwaySurgical airway

• Training & experience requiredTraining & experience required• Practicality in anticipated environmentPracticality in anticipated environment

Airway ProtectionAirway Protection Non-invasive ventilation predisposes to Non-invasive ventilation predisposes to

gastric insufflationgastric insufflation• Increased risk of aspirationIncreased risk of aspiration• Decreased pulmonary complianceDecreased pulmonary compliance

Risk of insufflation increases with Risk of insufflation increases with decreasing pulmonary compliance & LES decreasing pulmonary compliance & LES tonetone• Ongoing cardiac arrest + CPROngoing cardiac arrest + CPR• Asthma, COPDAsthma, COPD• Obesity, supine positionObesity, supine position

Airway ProtectionAirway Protection 35% of arrest survivors aspirated35% of arrest survivors aspirated How does aspiration kill?How does aspiration kill?

• Mechanical airway obstructionMechanical airway obstruction• Irritant laryngo- or bronchospasmIrritant laryngo- or bronchospasm• Hemorrhagic pneumonia (~6 hrs)Hemorrhagic pneumonia (~6 hrs)• ARDSARDS

Hypoxemic respiratory failureHypoxemic respiratory failure

Complications of ETIComplications of ETI Low success rates in absence of RSILow success rates in absence of RSI Risk of aspiration w/ RSIRisk of aspiration w/ RSI Delayed transport to hospitalDelayed transport to hospital Raised ICPRaised ICP Unrecognized esphageal intubationUnrecognized esphageal intubation Displacement or obstruction of ETTDisplacement or obstruction of ETT Pneumothorax Pneumothorax tension PTX tension PTX

A Slippery Slope?A Slippery Slope?

Perceived Risk of Aspiration

Pre-hospital RSI

Failed Intubations

RSI w/Paralytics

Failed Intubation

Alternative Airwayor Cricothyrotomy

Death, Delayed Transport, Other Complications

Airway Control

Perceived Risk of AspirationETI

Failure to Intubate RSI / paralyticsEsophageal

IntubationLoss of airway

Underutilization of alternative airway techniques

Cricothyrotomy

Death

Other complicatins

AspirationNeed for End-tidal

CO2 detectors, EDD, Etc

Extensive Training &Experience

Cricothyrotomytraining as truerescue airwayonly

Paralytics only in select cases under strict medical control

BVM + OPA

CombitubeUse of LMA +/- ILMA

Adequate ventilation &oxygenation + quick transportto definitive care facility

Should we just keep it simple?Should we just keep it simple?

BVMBVM ““there needs to be some alternatives to there needs to be some alternatives to

BVM. Although its use has been BVM. Although its use has been encouraged for many years, most encouraged for many years, most providers do not perform this skill well”providers do not perform this skill well”

Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6 ““In unskilled hands, maintaining a patent In unskilled hands, maintaining a patent

airway whilst at the same time attempting airway whilst at the same time attempting to ventilate the patient is not easy and is to ventilate the patient is not easy and is performed badly….alternative airway performed badly….alternative airway devices..may be better than an OPA and devices..may be better than an OPA and BVM”BVM”

Nolan. Curr Opinion Crit Care. 2001; 7:413-21Nolan. Curr Opinion Crit Care. 2001; 7:413-21

Tidal VolumeTidal Volume Balance b/w risk of gastric inflation Balance b/w risk of gastric inflation

and benefit of pulmonary ventilationand benefit of pulmonary ventilation Several studies demonstrate that Several studies demonstrate that

smaller TV’s decrease gastric smaller TV’s decrease gastric distention, but may not achieve distention, but may not achieve adequate P0adequate P022 unless suppl O unless suppl O2 2 is usedis used

ACLS 2000: ACLS 2000: • W/ OW/ O22 use TV 6-7 ml/kg over 2 sec use TV 6-7 ml/kg over 2 sec• W/O OW/O O22 use TV 10 ml/kg over 2 sec use TV 10 ml/kg over 2 sec

Pre-hospital RSIPre-hospital RSI Widespread use US; less in CanadaWidespread use US; less in Canada Locally EMS RSI introduced 2000Locally EMS RSI introduced 2000 Reported success rate 75-96.6%Reported success rate 75-96.6% Complication rates 5 – 13%Complication rates 5 – 13% Cricothyrotomy rates 1.1 – 14.9%Cricothyrotomy rates 1.1 – 14.9%

• Bulger et al. J Emerg Med 2002; 23: 181-9Bulger et al. J Emerg Med 2002; 23: 181-9 Local success rate ~84%Local success rate ~84% Calgary EMS 2-10 tubes/yrCalgary EMS 2-10 tubes/yr Local cricothyrotomy rate ~3%Local cricothyrotomy rate ~3%

Components of EMS RSI SystemComponents of EMS RSI System NAEMSP Position PaperNAEMSP Position Paper

• Medical direction & supervisonMedical direction & supervison• Intensive training including OR-based Intensive training including OR-based

experience & continuing education programsexperience & continuing education programs• Tools for placement confirmation & continous Tools for placement confirmation & continous

monitoringmonitoring• Drug delivery & storage provisionsDrug delivery & storage provisions• Standardized RSI protocolsStandardized RSI protocols• Rescue methods & devicesRescue methods & devices• QI / QA programs & performance reviewsQI / QA programs & performance reviews

Wang et al. Prehosp Emerg Care. 2001; 5: 40-8Wang et al. Prehosp Emerg Care. 2001; 5: 40-8

Intubation ConditionsIntubation Conditions The FieldThe Field

• Fewest helpers & equipmentFewest helpers & equipment• Least trained & experienced personnelLeast trained & experienced personnel• Awkward positioning & access to ptAwkward positioning & access to pt• Difficulty maintaining calm environmentDifficulty maintaining calm environment

Intubation ConditionsIntubation Conditions The EDThe ED

• More helpMore help• More equipmentMore equipment• Better trained & more experienced Better trained & more experienced

personnelpersonnel• Better monitoring of patientBetter monitoring of patient• Calmer conditionsCalmer conditions• Ability to carry out advanced Ability to carry out advanced

interventions under sterile conditonsinterventions under sterile conditons

ETT TrainingETT Training 20 year review of Pre-hospital ETI in 20 year review of Pre-hospital ETI in

Whatcom County, WashingtonWhatcom County, Washington 1657 adults underwent RSI w/ sux1657 adults underwent RSI w/ sux 210 (13%) aspirated (1.2% after sux)210 (13%) aspirated (1.2% after sux) 96.2% successfully intubated w/ sux96.2% successfully intubated w/ sux

• 3 cricothyrotomies3 cricothyrotomies• 6 esophageal intubations6 esophageal intubations

• 131 pediatric pts131 pediatric pts 97.6% successfully intubated w/ sux97.6% successfully intubated w/ sux

Wayne et al. Prehosp Emerg Care 1999; 13: 107-9Wayne et al. Prehosp Emerg Care 1999; 13: 107-9

ETT TrainingETT Training• Pre-hospital ETI Training in Whatcom County, Pre-hospital ETI Training in Whatcom County,

WashingtonWashington 2500 hrs to achieve certification2500 hrs to achieve certification >> 20 intubations in OR 20 intubations in OR >> 1 ETI /month & 1/yr in OR to maintain certification 1 ETI /month & 1/yr in OR to maintain certification

in first 3 yrsin first 3 yrs Subsequently > 1 ETI q3mo & 1 in ORSubsequently > 1 ETI q3mo & 1 in OR

Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6• SeattleSeattle

Similar training requirementsSimilar training requirements Animal lab q2yrs for surgical airway skillsAnimal lab q2yrs for surgical airway skills

Bulger et al. J Emerg Med 2002; 23: 183-9Bulger et al. J Emerg Med 2002; 23: 183-9

TrainingTraining ““no clear consensus on the number of no clear consensus on the number of

intubations required to train prehospital intubations required to train prehospital personnel adequately or on the number personnel adequately or on the number they need to undertake to maintain their they need to undertake to maintain their skills. In comparison with anesthesiology skills. In comparison with anesthesiology trainees, all these paramedic students are trainees, all these paramedic students are undertaking far fewer intubations.”undertaking far fewer intubations.”

Nolan. Curr Opinion Crit Care. 2001; 7:413-21Nolan. Curr Opinion Crit Care. 2001; 7:413-21 Experience & success rate in anesthesia Experience & success rate in anesthesia

residentsresidents• >58 intubations req’d for >90% success rate>58 intubations req’d for >90% success rate• >90 intubations req’d for >95% success rate>90 intubations req’d for >95% success rate

Konrad et al. Anesth Analg. 1998; 86: 635-9Konrad et al. Anesth Analg. 1998; 86: 635-9

Success Rate Success Rate Pre-hospital intubation 75-98.4%Pre-hospital intubation 75-98.4% Paramedic students in OR settingParamedic students in OR setting

• 94% 194% 1stst try LMA vs. 69% ETT try LMA vs. 69% ETT• 10% failed ETT vs 0% LMA10% failed ETT vs 0% LMA

Pennant & Walker. Anest Analg 1992. 74: 531-Pennant & Walker. Anest Analg 1992. 74: 531-3434

Novices trained on 110 pts in ORNovices trained on 110 pts in OR• 94% success with LMA vs. 51% w/ ETT94% success with LMA vs. 51% w/ ETT

Davies et al. Lancet. 1990. 336: 977Davies et al. Lancet. 1990. 336: 977

Failed IntubationsFailed Intubations 56/592 (9.5%) failed PH-ETI’s56/592 (9.5%) failed PH-ETI’s Various factorsVarious factors

• Inadequate relaxation (no RSI) 49%Inadequate relaxation (no RSI) 49%• Difficult anatomy 20%Difficult anatomy 20%• Obstruction 10%Obstruction 10%• 86% of failed pre-hospital intubations had their 86% of failed pre-hospital intubations had their

airway captured successfully in the EDairway captured successfully in the ED• Predict only 3.7% of prehospital ETI would Predict only 3.7% of prehospital ETI would

benefit from RSI drugsbenefit from RSI drugs• Wang et al. Prehosp Emerg Care. 2001; 5: 314-141Wang et al. Prehosp Emerg Care. 2001; 5: 314-141

How Do EP’s Compare?How Do EP’s Compare? NEAR NEAR (National Emergency Airway Registry)(National Emergency Airway Registry)

• 6294 ED intubations by EP’s6294 ED intubations by EP’s• 99% success rate99% success rate• Cricothyrotomy <1%Cricothyrotomy <1%

RSI in SeattleRSI in Seattle Retrospective study of 2614 pts who Retrospective study of 2614 pts who

underwent intubationunderwent intubation• 5.4% intubation rate5.4% intubation rate• 50% underwent RSI w/ Sux50% underwent RSI w/ Sux• 98.4% success rate98.4% success rate• 1.1% surgical airway rate1.1% surgical airway rate• 0.6% unabale to achieve airway – BVM0.6% unabale to achieve airway – BVM• No long-term outcome, # of intubation No long-term outcome, # of intubation

attempts, or scene time dataattempts, or scene time data Bulger et al. J Emerg Med 2002; 23: 183-9Bulger et al. J Emerg Med 2002; 23: 183-9

Does Sux Improve Outcome?Does Sux Improve Outcome? “…“…whether succinylcholine-assisted whether succinylcholine-assisted

ventilation makes a real difference, but ventilation makes a real difference, but not enough data are available to answer not enough data are available to answer it…”it…”

““..personal observation suggest the ..personal observation suggest the outcome is noticeably improved..”outcome is noticeably improved..”

““A problem with obtaining valid outcomes A problem with obtaining valid outcomes data is that the use of a direct control data is that the use of a direct control group would negate the standard of care”group would negate the standard of care”

Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6

Does Sux Improve Outcome?Does Sux Improve Outcome? There really seems little doubt that use of There really seems little doubt that use of

drugs increases success rates especially in drugs increases success rates especially in trauma ptstrauma pts

4 studies totalling 2446 pts of paramedics 4 studies totalling 2446 pts of paramedics using drugs for ETI w/ success rates of using drugs for ETI w/ success rates of 90.5% for midaz only – 97.9% for midaz + 90.5% for midaz only – 97.9% for midaz + suxsux

Rates for PH-ETI w/o drugs range from Rates for PH-ETI w/o drugs range from 49%-96%49%-96%

Nolan. Curr Opinion Crit Care. 2001; 7:413-21Nolan. Curr Opinion Crit Care. 2001; 7:413-21

Prehospital RSI in CHIPrehospital RSI in CHI Prospective case-control study of 209 Prospective case-control study of 209

head-injured adult trauma victims head-injured adult trauma victims compared to 627 hand-matched controlscompared to 627 hand-matched controls

excluded pts intubated w/o RSI from both excluded pts intubated w/o RSI from both groupsgroups

all pts first had non-RSI attempts at ETIall pts first had non-RSI attempts at ETI paramedics had 8 hr training course in RSIparamedics had 8 hr training course in RSI

Davis et al. J Trauma. 2003; 54: 444-53Davis et al. J Trauma. 2003; 54: 444-53

Inclusion CriteriaInclusion Criteria >18yo>18yo major trauma (county protoclos)major trauma (county protoclos) suspected CHIsuspected CHI GCS 3-8GCS 3-8 estimated transport to ED > 10 minestimated transport to ED > 10 min unsuccessful non-RSI intubation unsuccessful non-RSI intubation

attemptattempt

Exclusion CriteriaExclusion Criteria Inabilty to capture airway (ETI or CTI) Inabilty to capture airway (ETI or CTI)

following RSIfollowing RSI no head injury (H + N AIS < 2)no head injury (H + N AIS < 2) H & N AIS defined by neck injuryH & N AIS defined by neck injury failure to fulfill MTOS criteriafailure to fulfill MTOS criteria death in field or ED w/in 30 min of arrivaldeath in field or ED w/in 30 min of arrival any patient intubated w/o RSIany patient intubated w/o RSI unable to start IV or CPR before RSI unable to start IV or CPR before RSI

OutcomesOutcomes DeathDeath ““good outcome”good outcome”

• discharge todischarge to homehome rehabilitation (not for long term care)rehabilitation (not for long term care) psychiatrypsychiatry jailjail LAMALAMA

ResultsResults RSI increased successful intubations but also RSI increased successful intubations but also

increased mortality (33% vs 24.2% OR 1.6 increased mortality (33% vs 24.2% OR 1.6 [1.2-2.2]) and decreased “good” outcomes [1.2-2.2]) and decreased “good” outcomes (45.5% vs. 57.9%, OR 1.6 [1.2-2.3])(45.5% vs. 57.9%, OR 1.6 [1.2-2.3])

largest difference noted for most severely largest difference noted for most severely injured ptsinjured pts

longer scene times w/ RSIlonger scene times w/ RSI more inadvertent hyperventilation w/ RSImore inadvertent hyperventilation w/ RSI inc’d mortality w/ single (37.4%) vs. multiple inc’d mortality w/ single (37.4%) vs. multiple

(26.7%) intubation attempts (no P value given)(26.7%) intubation attempts (no P value given)

Study ConclusionsStudy Conclusions Prehospital RSI causes increased Prehospital RSI causes increased

mortality and morbiditymortality and morbidity Trial suspended until cause for Trial suspended until cause for

increased mortality can be increased mortality can be determineddetermined

CriticismsCriticisms Did not compare RSI-intubated pts w/ Did not compare RSI-intubated pts w/

non-RSI intubated ptsnon-RSI intubated pts by inclusion criteria, all pts had at least 2 by inclusion criteria, all pts had at least 2

attempts at intubationattempts at intubation minimal training & experience in RSIminimal training & experience in RSI 67 / 209 pts ultimately had minor or no 67 / 209 pts ultimately had minor or no

head injury head injury no power calculationno power calculation not randomizednot randomized

My ConclusionsMy Conclusions Methodologic flaws make drawing Methodologic flaws make drawing

conclusions difficultconclusions difficult Taken together with other recent Taken together with other recent

studies suggests that prehospital RSI studies suggests that prehospital RSI intubation may be harmfulintubation may be harmful

RSIRSI Consensus meeting failed to Consensus meeting failed to

embrace pre-hospital RSIembrace pre-hospital RSI Lack of evidence for its benefit Lack of evidence for its benefit

Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6

ComplicationsComplications Surgical airwaySurgical airway

• 1.1 – 14.9%1.1 – 14.9% A review of failed pre-hospital airway A review of failed pre-hospital airway

mgmt cases demonstratedmgmt cases demonstrated• Questionable indications for intubationQuestionable indications for intubation• Lack of alternative rescue techniques Lack of alternative rescue techniques

employed prior to cricothyrotomyemployed prior to cricothyrotomy• Extensive complicationsExtensive complications

Mizelle et al. Prehosp Emerg Care. 2002; 6:472-75Mizelle et al. Prehosp Emerg Care. 2002; 6:472-75

Unrecognized Esophageal IntubationUnrecognized Esophageal Intubation PH-ETI with drugsPH-ETI with drugs

• 0.4% rate in 2 retrospective studies0.4% rate in 2 retrospective studies Wang et al. Prehosp Emerg Care. 2001; 5: 134-41Wang et al. Prehosp Emerg Care. 2001; 5: 134-41 Wang et al. Prehosp Emerg Care. 1999; 3: 377-78Wang et al. Prehosp Emerg Care. 1999; 3: 377-78

PH-ETI without drugsPH-ETI without drugs• Prospective observational study in urban EMSProspective observational study in urban EMS• 108 pts had ETT placement checked upon arrival in ED:108 pts had ETT placement checked upon arrival in ED:

““Clearly misplaced” (epigastric sounds, vomitus per tube) – only in Clearly misplaced” (epigastric sounds, vomitus per tube) – only in 4 / 27 pts not confirmed by direct laryngoscopy4 / 27 pts not confirmed by direct laryngoscopy

ETCOETCO33 for all pts for all pts Auscaultation & direct laryngoscopyAuscaultation & direct laryngoscopy

• 25% misplaced (18/27 in esophagus)25% misplaced (18/27 in esophagus)• ETCOETCO22 use in field purposely not recorded use in field purposely not recorded• No central direct medical oversight of EMSNo central direct medical oversight of EMS• Concluded rate of misplacement much higher than thoughtConcluded rate of misplacement much higher than thought

Katz & Falk. Ann Emerg Med. 2001; 37: 62-4Katz & Falk. Ann Emerg Med. 2001; 37: 62-4

Verifying Tube PositionVerifying Tube Position ETCOETCO22 is the recommended gold standard in all is the recommended gold standard in all

locationslocations Prospective study of self-inflating bulb EDD in 65 Prospective study of self-inflating bulb EDD in 65

pts intubated in ED for cardiac arrestpts intubated in ED for cardiac arrest EDD 100% (5/5) sens for esophageal placement, EDD 100% (5/5) sens for esophageal placement,

but 18 false +ve’s (poor spec)but 18 false +ve’s (poor spec) ETCOETCO22 100% sens for esophageal placement, but 100% sens for esophageal placement, but

also no ETCOalso no ETCO22 in 26/60 tracheal intubations in 26/60 tracheal intubations EDD & ETCOEDD & ETCO22 together only have 90.8% sensitivity together only have 90.8% sensitivity

for tracheal placementfor tracheal placement Tanigawa et al. Anesthesiology. 2000; 93: 1432-6 Tanigawa et al. Anesthesiology. 2000; 93: 1432-6

Other studies suggest the syringe EDD is 99% Other studies suggest the syringe EDD is 99% sensitive for tracheal intubationsensitive for tracheal intubation

Bozeman et al. Ann Emerg Med 1996; 27: 595-9Bozeman et al. Ann Emerg Med 1996; 27: 595-9

Verifying Tube PositionVerifying Tube Position Other studies suggest the syringe EDD is 99% Other studies suggest the syringe EDD is 99%

sensitive for tracheal intubationsensitive for tracheal intubation Bozeman et al. Ann Emerg Med 1996; 27: 595-9Bozeman et al. Ann Emerg Med 1996; 27: 595-9

Prospective randomized X-over studyProspective randomized X-over study 48 cardiac arrest pts intubated in ED48 cardiac arrest pts intubated in ED SIB, Syringe ETT, & ETCOSIB, Syringe ETT, & ETCO22 No sig differences b/w the 2 EDD’sNo sig differences b/w the 2 EDD’s Similar sensitivity for tracheal intubation (70.8-Similar sensitivity for tracheal intubation (70.8-

72.9%) as previous study72.9%) as previous study 100% sens (8) for esophageal intubation100% sens (8) for esophageal intubation

Tanigawa et al. Anesth Analg 2001; 92: 375-8Tanigawa et al. Anesth Analg 2001; 92: 375-8 All studies hampered by small sample size & lack All studies hampered by small sample size & lack

of a consistent gold-standardof a consistent gold-standard

Outcome Data for ETIOutcome Data for ETI ““there are no well-controlled, there are no well-controlled,

prospective studies showing that prospective studies showing that outcome is influenced by tracheal outcome is influenced by tracheal intubation by paramedics”intubation by paramedics”

Nolan. Curr Opinion Crit Care. 2001; 7:413-21Nolan. Curr Opinion Crit Care. 2001; 7:413-21

Outcome Data for ETIOutcome Data for ETI Anti-ETIAnti-ETI

• Prospective, odd-even day randomized BVM vs. ETI analyzed as ITT analysisProspective, odd-even day randomized BVM vs. ETI analyzed as ITT analysis• 820 pts < 12 yo820 pts < 12 yo• 57% success rate for ETI days (174/305)57% success rate for ETI days (174/305)• No difference in survival (OR 0.82; 95%CI 0.61-1.11) or neurological outcome (OR 0.87; 95%CI 0.62-1.22)No difference in survival (OR 0.82; 95%CI 0.61-1.11) or neurological outcome (OR 0.87; 95%CI 0.62-1.22)• significantly better outcome w/ BVM in 3 subgroupssignificantly better outcome w/ BVM in 3 subgroups

Foreign body aspiration (neuro OR 0.13; 95%CI 0.02-0.76)Foreign body aspiration (neuro OR 0.13; 95%CI 0.02-0.76) Respiratory arrest b( mortalitly OR 0.27; 95%CI 0.11-0.69)Respiratory arrest b( mortalitly OR 0.27; 95%CI 0.11-0.69) Child maltreatment (mortality OR OR 0.07; 95%CI 0.01-0.58)Child maltreatment (mortality OR OR 0.07; 95%CI 0.01-0.58)

• no differendes in pulse oximetryno differendes in pulse oximetry• Complications:Complications:

3 (2%) esophageal intubations3 (2%) esophageal intubations 12 (6%) unrecognized dislodgement12 (6%) unrecognized dislodgement 33 (18%) mainstem bronchus intubation33 (18%) mainstem bronchus intubation 44 (24%) wrong tube size44 (24%) wrong tube size 14/15 died due to esophageal intubation or dislodgement14/15 died due to esophageal intubation or dislodgement equal rate of vomiting and aspiration in both groupsequal rate of vomiting and aspiration in both groups

• Signifantly longer scene & total transport times for ETISignifantly longer scene & total transport times for ETI• Paramedics w/ adult ETI experience but only 6 hrs of classroom training in pediatric airway; no paralyticsParamedics w/ adult ETI experience but only 6 hrs of classroom training in pediatric airway; no paralytics• Conclude that pre-hospital ETI does not improve outcome over BVM and should not be incorporated into EMS careConclude that pre-hospital ETI does not improve outcome over BVM and should not be incorporated into EMS care

Gaushe et al. JAMA 2000; 283: 783-90 Gaushe et al. JAMA 2000; 283: 783-90

Outcome Data for ETIOutcome Data for ETI Pro ETIPro ETI

• Retrospective case-control studyRetrospective case-control study• 1092 blunt trauma pts w/ GCS 1092 blunt trauma pts w/ GCS << 8 8 • ALS crews, no paralytics or sedationALS crews, no paralytics or sedation• 51.7% intubated51.7% intubated

• Significantly less mortality in ETI group (26%) vs non-Significantly less mortality in ETI group (26%) vs non-ETI group (36%) for all comers, BUT more people able ETI group (36%) for all comers, BUT more people able to be discharged home in non ETI group (63.1% vs. to be discharged home in non ETI group (63.1% vs. 54.8%)54.8%)

• odds ratio for mortality 1.6 for all ptsodds ratio for mortality 1.6 for all pts• odds ratio for mortality 3.0 for isolated severe CHI odds ratio for mortality 3.0 for isolated severe CHI

subgroup (but no difference in morbidity)subgroup (but no difference in morbidity)• also separately calculated Aeromedical data found sig also separately calculated Aeromedical data found sig

increase in mortality for ETI pts (35%) vs non-increase in mortality for ETI pts (35%) vs non-intubated pts (21%) all comers -- attributed to sicker intubated pts (21%) all comers -- attributed to sicker ptspts

• Concluded PH-ETI saves livesConcluded PH-ETI saves lives Winchell & Hoyt. Arch Surg. 1997; 132: 592-97Winchell & Hoyt. Arch Surg. 1997; 132: 592-97

CriticismsCriticisms• no comparison of intubation attempts b/w no comparison of intubation attempts b/w

groups groups • no data on why the non-ETI pts were not no data on why the non-ETI pts were not

intubatedintubated• no scene time datano scene time data• not randomized or prospectivenot randomized or prospective• don’t comment on discrepancies, and ignore don’t comment on discrepancies, and ignore

other dataother data• no sample size estimate / power calc’nno sample size estimate / power calc’n

My ConclusionsMy Conclusions At best this study fails to show a At best this study fails to show a

difference in functional outcomedifference in functional outcome At worst it suggest that functional At worst it suggest that functional

outcome is actually better in the non-outcome is actually better in the non-ETI group, and that mortality is ETI group, and that mortality is increased by ETI by aeromedical increased by ETI by aeromedical crewscrews

Anti Prehospital ETIAnti Prehospital ETI Grant et al. J Trauma. 2003; 54: 307-Grant et al. J Trauma. 2003; 54: 307-

1111• Prospective cohort study on 191 adult Prospective cohort study on 191 adult

trauma ptstrauma pts• 41% intubated in field, 59% in ED41% intubated in field, 59% in ED• 92% blunt trauma92% blunt trauma

Inclusion & Exclusion CriteriaInclusion & Exclusion Criteria InclusionInclusion

• GCS GCS << 8 + HAIS 8 + HAIS >> 3 3• intubated in field or in EDintubated in field or in ED

ExclusionExclusion• death w/in 48 hrs death w/in 48 hrs • failed field intubationsfailed field intubations• extrication >30 minextrication >30 min• on-site physicianson-site physicians• transferstransfers

ResultsResults Sig increase in prehospital group of:Sig increase in prehospital group of:

• mortality (23% vs 12.4%, OR 1.85)mortality (23% vs 12.4%, OR 1.85)• Pneumonia (49% vs 32%)Pneumonia (49% vs 32%)• ICU days (15.2+/-9.3 vs 11.7+-7.8)ICU days (15.2+/-9.3 vs 11.7+-7.8)• Hospital days (20.2+/-12.6 vs 16.7+/-Hospital days (20.2+/-12.6 vs 16.7+/-

10.9)10.9)• ventilator days (14.7+/-11 vs 10.4+/-8.7)ventilator days (14.7+/-11 vs 10.4+/-8.7)

longer scene times for PH-ETIlonger scene times for PH-ETI

ConclusionsConclusions Field intubation associated with Field intubation associated with

higher mortality & morbidity than higher mortality & morbidity than intubation in the EDintubation in the ED

recommend RCT to define more recommend RCT to define more clearly which pts may benefit fclearly which pts may benefit f

CriticismsCriticisms ED intubation by trauma anesthetistED intubation by trauma anesthetist non-significant trend towards higher non-significant trend towards higher

incidence of ICH in ED groupincidence of ICH in ED group sig higher rate of neurosurgical sig higher rate of neurosurgical

intervention in ED groupintervention in ED group heterogeneity in EMS training heterogeneity in EMS training exclusion of acute fatalities exclusion of acute fatalities no long-term datano long-term data

““While the potential benefits of While the potential benefits of successful prehospital tracheal successful prehospital tracheal intubation remain controversial, the intubation remain controversial, the harm caused by unrecognized harm caused by unrecognized esophageal intubation is esophageal intubation is indisputable”indisputable”

Nolan. Curr Opinion Crit Care. 2001; 7: 413-21Nolan. Curr Opinion Crit Care. 2001; 7: 413-21

LMALMA

Types of LMATypes of LMA Standard LMAStandard LMA ProSeal™ LMAProSeal™ LMA

• gastric drainage channelgastric drainage channel• Deeper bowlDeeper bowl• Additional cuff on dorsumAdditional cuff on dorsum

(ILMA)(ILMA)• Metal tubingMetal tubing• Specific silicone ETTSpecific silicone ETT

Quoted Pro’s & Con’s of LMAQuoted Pro’s & Con’s of LMA CON’sCON’s

• Does not protect against aspirationDoes not protect against aspiration• Appears to promote LES relaxationAppears to promote LES relaxation• Not as suitable for PPVNot as suitable for PPV

PRO’sPRO’s• Easy & fast to insert w/ minimal training Easy & fast to insert w/ minimal training • Single operatorSingle operator• Less gastric insufflation than BVMLess gastric insufflation than BVM• Minimal C-spine manipulationMinimal C-spine manipulation• Less traumaticLess traumatic• Minor cardiovascular responseMinor cardiovascular response

Time to Airway controlTime to Airway control Prevailing doctrine = “scoop-and-run” – time is clearly criticalPrevailing doctrine = “scoop-and-run” – time is clearly critical LMA insertion 22.3 sec vs 36.5 for ETT vs 40 sec for ETC under LMA insertion 22.3 sec vs 36.5 for ETT vs 40 sec for ETC under

combat conditions on mannequinscombat conditions on mannequins Calkins et al. J Trauma. 1999. 46: 927-32Calkins et al. J Trauma. 1999. 46: 927-32

Paramedics & RT’s in OR settingParamedics & RT’s in OR setting• Mean time to ventilate w/ LMA 38.9+/-1.9 sec vs 206.1+/-31.9 sec w Mean time to ventilate w/ LMA 38.9+/-1.9 sec vs 206.1+/-31.9 sec w

ETTETT Reinhart. Ann Emerg Med. 1994; 24: 260-3Reinhart. Ann Emerg Med. 1994; 24: 260-3

Trainees in OR setting:Trainees in OR setting:• 20 sec w/ LMA vs. 35 sec w/ ETT20 sec w/ LMA vs. 35 sec w/ ETT

Davies et al. Lancet. 1990. 336: 977Davies et al. Lancet. 1990. 336: 977 Air rescue crewmembers for failed intubationAir rescue crewmembers for failed intubation

• 5 min spent attempting intubation5 min spent attempting intubation• Avg 10 sec to placement of LMAAvg 10 sec to placement of LMA

Martin et al. J Trauma; 47: 352-57Martin et al. J Trauma; 47: 352-57 Paramedic students in OR settingParamedic students in OR setting

• 38.6 sec LMA vs 88.3 sec ETT38.6 sec LMA vs 88.3 sec ETT Pennant & Walker. Anest Analg 1992. 74: 531-34Pennant & Walker. Anest Analg 1992. 74: 531-34

TrainingTraining Novice success w/ minimal training suggests Novice success w/ minimal training suggests

minimal deterioration of skill over timeminimal deterioration of skill over time• Davies et al. Lancet. 1990. 336: 977Davies et al. Lancet. 1990. 336: 977

Significantly more instruction required for ETT Significantly more instruction required for ETT than LMA than LMA

• Pennant & Walker. Anest Analg 1992. 74: 531-34Pennant & Walker. Anest Analg 1992. 74: 531-34 Paramedics & RT’s previously trained in Paramedics & RT’s previously trained in

intubation but not LMA inserion in OR settingintubation but not LMA inserion in OR setting• Attempts 1 for LMA vs 2.22+/-0.21 for ETTAttempts 1 for LMA vs 2.22+/-0.21 for ETT• VA score of difficulty 8.64 for LMA vs 67.3 for ETTVA score of difficulty 8.64 for LMA vs 67.3 for ETT

Reinhart. Ann Emerg Med. 1994; 24: 260-3Reinhart. Ann Emerg Med. 1994; 24: 260-3

Aspiration + the LMAAspiration + the LMA Theoretical concern; min evidenceTheoretical concern; min evidence Incidence of aspiration unknown in Incidence of aspiration unknown in

prehospital setting for both ETT + prehospital setting for both ETT + LMALMA

““In the prehospital setting, the In the prehospital setting, the theoretical possibility of gastric theoretical possibility of gastric aspiration has been suggested but aspiration has been suggested but not proven.”not proven.”

Martin et al. 1999 J Trauma; 47: 352-57Martin et al. 1999 J Trauma; 47: 352-57

Regurgitation: LMA vs BVMRegurgitation: LMA vs BVM Prospective analysis of 797 in-Prospective analysis of 797 in-

hospital resuscitationshospital resuscitations• Regurgitation in 180 pts totalRegurgitation in 180 pts total• 96 cases after starting airway mgmt96 cases after starting airway mgmt

3/96 (3.5%) w/ LMA only (n=86)3/96 (3.5%) w/ LMA only (n=86) 58/96 (12.4%) w/ BVM only (n=466)58/96 (12.4%) w/ BVM only (n=466) Statistically significant difference P <0.05Statistically significant difference P <0.05

• No data on aspiration or mortalityNo data on aspiration or mortality• Not randomizedNot randomized

Stone et al. Resuscitation. 1998; 3: 3-6Stone et al. Resuscitation. 1998; 3: 3-6

Aspiration + LMAAspiration + LMA Prospective cohort study of 17 Prospective cohort study of 17

trauma pts ventilated via LMA during trauma pts ventilated via LMA during air transport after failing intubationair transport after failing intubation• Avg GCS 6 / ISS 28Avg GCS 6 / ISS 28• 5 min spent attempting intubation5 min spent attempting intubation• 94% 194% 1stst try placement try placement• Avg 10 sec to placementAvg 10 sec to placement• No evidence of aspirationNo evidence of aspiration

Martin et al. 1999. J Trauma; 47: 352-57Martin et al. 1999. J Trauma; 47: 352-57

Aspiration + the LMAAspiration + the LMA Retrospective review of surgical ptsRetrospective review of surgical pts

• Aspiration 1/11960 (0.009%)Aspiration 1/11960 (0.009%)• Regurgitation 4/11960 (0.03%)Regurgitation 4/11960 (0.03%)• 83.5% elective, only 1.36% 83.5% elective, only 1.36% >> ASA III ASA III

Verghese et al. Anesth Analg. 1996; 82: 129-133Verghese et al. Anesth Analg. 1996; 82: 129-133 w/ ILMA risk is 2.6/10000 elective + w/ ILMA risk is 2.6/10000 elective +

11/10000 emergency cases11/10000 emergency cases Dries et al. Air Med J. 2001. 20: 35-37Dries et al. Air Med J. 2001. 20: 35-37

3/146 cases of vomitus in airway at time of 3/146 cases of vomitus in airway at time of replacement of LMA by ETT in ED in replacement of LMA by ETT in ED in prospective analysisprospective analysis

Rumball & MacDonald. Prehosp Emerg Care. 1997; Rumball & MacDonald. Prehosp Emerg Care. 1997; 1: 1-101: 1-10

Aspiration + the LMAAspiration + the LMA ““..the inability to successfully ..the inability to successfully

manage difficult airways is manage difficult airways is responsible for 30% of deaths totally responsible for 30% of deaths totally attributable to anesthesia, whereas attributable to anesthesia, whereas aspiration pneumonitis per se is an aspiration pneumonitis per se is an infrequent cause of anesthesia infrequent cause of anesthesia related mortality”related mortality”

Brimacombe et al. J Clin Anesth. 1995; 7:297-Brimacombe et al. J Clin Anesth. 1995; 7:297-305305

Aspiration + the LMAAspiration + the LMA Meta-analysis of 12,901 ASA I-III pts revealed 3 Meta-analysis of 12,901 ASA I-III pts revealed 3

cases (2.3/10,000)cases (2.3/10,000) Only 1 was related to emergency anesthesiaOnly 1 was related to emergency anesthesia 18 case reports of aspiration w/ LMA18 case reports of aspiration w/ LMA

• 2 were related to emergency anesthesia2 were related to emergency anesthesia• none had long-term disabilitynone had long-term disability

Aspiration rate w/ ETT of 2.6/10,000 in elective Aspiration rate w/ ETT of 2.6/10,000 in elective surgery and 11/10,000 in emergency surgerysurgery and 11/10,000 in emergency surgery

Recommend AGAINST use of LMA in multi-trauma Recommend AGAINST use of LMA in multi-trauma pts based on case reportspts based on case reports

Brimacombe et al. J Clin Anesth. 1995; 7:297-305Brimacombe et al. J Clin Anesth. 1995; 7:297-305

LMALMA Insufficient data on LMA to make Insufficient data on LMA to make

recommendations regarding its use recommendations regarding its use in pre-hospital settingin pre-hospital setting

““the group was concerned about the the group was concerned about the learning curve required for its use”learning curve required for its use”

LMA provides some airway protection LMA provides some airway protection but is felt to be inferior to the ETTbut is felt to be inferior to the ETT

Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6Wayne et al. Prehosp Emerg Care. 1999; 3: 290-6

CombitubeCombitube

ComitubeComitube Double lumen Double lumen

airwayairway Distal & proximal Distal & proximal

cuffscuffs Blind placementBlind placement Provides some Provides some

protection against protection against aspirationaspiration

CombitubeCombitube ProsPros

ConsCons• Bulky, no pediatric sizesBulky, no pediatric sizes• ExpensiveExpensive• Esophageal rupture (> 3 cases reported)Esophageal rupture (> 3 cases reported)• May ventilate through wrong lumenMay ventilate through wrong lumen

Which Airway Device?Which Airway Device? Prospective pseudo-randomized crossover Prospective pseudo-randomized crossover

study of rural BLS crews comparing PTL, study of rural BLS crews comparing PTL, Combitube, LMA, + OA/BVMCombitube, LMA, + OA/BVM

Some were OR-trained, others were Some were OR-trained, others were manniquin-trainedmanniquin-trained

OR-trained EMT’s did better w/ LMA insertion OR-trained EMT’s did better w/ LMA insertion than manniquin-trained crewsthan manniquin-trained crews

All rated subjectively & objectively better All rated subjectively & objectively better than OA/BVMthan OA/BVM

Combitube rated best for ventilation + Combitube rated best for ventilation + preference by EMT’s but worst for ventilation preference by EMT’s but worst for ventilation when assessed by EPwhen assessed by EP

LMA best for ventilation in OR-trained groupLMA best for ventilation in OR-trained group Aimilar rates of aspiration (1.14 – 2.05%)Aimilar rates of aspiration (1.14 – 2.05%) 4/57 autopsies had aspiration:4/57 autopsies had aspiration:

3 in PTLA3 in PTLA 1 in LMA1 in LMA

No differences in survival-to-dischargeNo differences in survival-to-discharge No differences in On-scene – hospital timesNo differences in On-scene – hospital times LMA has highest training costs but lowest LMA has highest training costs but lowest

operating costs and operational cost / life operating costs and operational cost / life saved $417 vs $1650.37 for combitubesaved $417 vs $1650.37 for combitube

• Rumball & MacDonald. Prehosp Emerg Care. 1997; 1: 1-10Rumball & MacDonald. Prehosp Emerg Care. 1997; 1: 1-10

12200 non-traumatic cardiac arrest 12200 non-traumatic cardiac arrest pts in Japan managed by EMT’spts in Japan managed by EMT’s• Combitube failure to insert 6.9%Combitube failure to insert 6.9%• LMA failure to insert 10.5%LMA failure to insert 10.5%

Tanigawa & Shigematsu. Prehosp Emerg Care. Tanigawa & Shigematsu. Prehosp Emerg Care. 1998; 2: 96-1001998; 2: 96-100