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Three Part Question

In [patients with major trauma and head injury needing airway management in prehospital setting] is [endotracheal intubation better than bag and mask ventilation] for [improved outcomes]

Clinical Scenario

A 41 year old car driver was involved in a major road traffic accident, sustaining injuries to his head, a fracture of his right femur and multiple bruises on his chest. On scene he had altered sensorium and his GCS was estimated to be 5. He was intubated by the paramedics and brought to the Emergency Department. You wonder about the evidence in favour of endotracheal intubation as compared to bag and mask ventilation in trauma patients.

Search Strategy

Medline 1966-Week 4 August 2005 using the OVID interface
Embase 1980-2005 week 37
The Cochrane Library Issue 3 2005
Medline 1966-Week 4 August 2005 using the OVID interface, {Cochrane Prehospital Search filter} AND {exp Intubation, Intratracheal/ or endotracheal intubation.mp. OR ETI.mp. OR RSI.mp OR rapid sequence intubation.mp}
Embase 1980-2005 week 37, [exp Emergency Health Service/ OR exp Rescue Personnel/ OR exp Emergency Treatment/ OR exp Emergency Medicine/ OR exp Ambulance/ OR exp First Aid/ OR exp Military Medicine/] AND [intratracheal intubation.mp. OR exp Endotracheal Intubation/ OR ETI.mp. OR RSI.mp. OR rapid sequence intubation.mp. OR rapid sequence induction.mp.] LIMIT to Human, English Language, Abstracts, (adult <18 to 64 years> or aged <65+ years>) and Clinical Queries Prognosis filter – sensitive
The Cochrane Library Issue 3 2005, exp intubation, intratracheal [MeSH] AND exp Emergency Medical Services [ MeSH]

Search Outcome

4360 papers found, of which nine were relevant and of sufficient quality for inclusion. These are summarised in the table:

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Wang et al Nov 2004 USA	All trauma patients > 18 years sustaining severe traumatic brain injury who were intubated in prehospital or hospital setting	Retrospective cohort study	Prehospital versus hospital intubation mortality	OR of 3.99 (CI 3.21 to 4.93)	Non-randomised study, use of pre-existing and unvalidated registry, unvalidated functional impairment score, adjustment not done for some factors that could affect prehospital intubation, no information of course of ED airway care, Could not identify failed prehospital intubation efforts and analysis, propensity score used but matching techniques not used
			Prehospital versus hospital intubation poor neurologic outcomes	OR of 1.61 ( CI 1.15 to 2.26)
			Prehospital versus hospital intubation functional impairment	OR of 1.92 (CI 1.40 to 2.64) for moderate or severe
Stockinger ZT, McSwain NE 2004 USA	Review of records from Dec 1999 to sept 2002 who met level 1 trauma criteria and who received ETI or BVM ventilation	Retrospective cohort study	Overall mortality	65.3%	Retrospective design, record review, not controlled, small number of ETI survivors to compare functional outcomes or prehospital transit time, inadequately matched groups
			Penetrating injury mortality	OR 1.78 (CI 1.54 to 2.05)
			Patients receiving ETI mortality	OR 2.88 (CI 2.36 to 3.54)
			Penetrating injury and ETI mortality versus blunt injury and ETI mortality	95.8% and 78.4%, p<0.0001
			Penetrating injury and BVM mortality	53.5% p<0.0001
			Different ISS,ETI versus BVM	ETI worse than BVM p<0.0001
			Prehospital time ETI versus BVM	Longer time on ETI but only by 1.9 minutes
			Increasing RTS ETI versus BVM mortality	Mortality worse in ETI patients p>0.05
			TRISS model actual deaths vs predicted deaths	ETI mortality worse than BVM p<0.05
Davis et al 2003 USA	Adult major Trauma victims with severe head injuries >18 yrs, suspected head injury by mechanism or physical findings, GCS 3-8, estimated time for transport >10 minutes, exclusion if unable to achieve IV access or needed PR before RSI	Prospective cohort study 209 patients who received ETI matched to 627 historical controls who did not	Mortality in ETI versus BVM ventilation	33% VERSUS 24.2%, OR 1.6(CI 1.1 to 2.2)	Cohort sudy with historical controls though matched well, GCS not used for matching as they were not consistently calculated pre-trial cohort and omitted from trial cohort as they were paralysed and intubated, higher mortality in RSI cohorts who had low pCO2, possibility of hyperventilation contributing to increased mortality, other parameters may have been present which were unmatched in the two groups
			Good outcome ETI versus BVM	45.5% versus 57.9% OR 1.6(1.2-2.3 CI)
			Total days in ICU ETI versus BVM	7.1% versus 6%, non-significant
			Total days in hospital ETI versus BVM	12.2% versus 14.5% non-significant
Bochichhio et al 2003 USA	Data collected on 191 patients admitted to a trauma centre with field GCS <=8, head Abbreviated Injury Scale >=3 who were intubated (78) in the field or intubated on arrival to hospital (113), patients who died within 48 hrs excluded	Prospective cohort study	Dispatch time field ETI versus hospital ETI	p<0.05	Cohort study, death within 48 hrs excluded, individual paramedic bais in intubation, difference between ground and state patrol flight paramedics, lack of longterm data or functional outcomes, bias on the practice of neurosurgeon
			Field ETI versus hospital ETI	23% versus 12.4% (p=0.05), OR 1.85
			Field ETI versus hospital ETI respiratory complications	61% versus 29%, p<0.05
			Field ETI versus hospital ETI ICU stay	Longer in field ETI p<0.005
Sloane et al 2000 USA	All adult trauma patients who underwent prehospital RSI 1988 to 1995 (47 patients) compared with those who had RSI upon arrival to trauma resuscitation suite 1992-1995 (537 patients) as per RSI protocol	Retrospective study	Field intubation versus hospital intubation success rates	97.9% versus 98.5%	Retrospective study, small sample of field intubation, matching not adequate esp. related to age, retrospective definition of number of attempts at intubation and record review, field patients had worse trauma severity scores, no blinding of data collector
			Attempts to reach successful intubation	No significant difference
			Field intubation time versus hospital intubation time in transit	25.7 mins versus 14.2 mins, p<0.01
			Field and hospital intubation immediate and long term complication	No difference
			Field and hospital intubation pneumonia	28% versus 6% p<0.001
			Length of stay ICU and hospital field and hospital intubation	No significant difference
			Mortality in field and hospital intubations in head injured subgroups	14% in field and 22% in hospital subgroups p=0.54
Eckstein et al 2000 USA	All adult patients from 1993 to 1995 who met trauma centre criteria, had airway intervention performed by paramedics and transprted to medical centre, ETI or BVM done as per hospital policy, 93 patients had ETI and 403 BVM	Retrospective cohort study	Prehospital transit time for ETI versus BVM	12.8 mins versus 11 mins p=0.09	Data obtained from paramedic field reports, retrospective study, groups compared by covariates and not true controls, effect of hyperventilation not studied, small number of patients with ETI, despite adjustment for ISS through logistic regression, ETI group had a very high mortality based on ISS, limitations of ISS, RSI not used
			Mortality in ETI versus BVM after adjustment for sex, mechanism and ISS,	93% versus 67%, OR 5.3 (CI 2.3 to 14.2)
			Patients not receiving IV fluids mortality	OR 3.9 (CI 1.0 to 26.7)
Murray et al 2000 USA	All adult patients with severe head injury GCS <=8, head AIS score >=3 over a 3 yr period 1995-1997 who were intubated (81) in the field or non-intubated (714) or unsuccessfully intubated (57)	Retrospective study, review of trauma registry	Crude mortality figures in intubated versus non-intubated group	82% versus 43%, OR 1.88 (CI 1.65 to 2.15)	Retrospective design, matching done but certain critical parameters missed out, selection bias, only patients with more severe injuries selected for intubation
			Mortality in matched groups intubated in field or non-intubated	OR 1.74 (CI 1.41-2.00)
			Adjusted unsuccessful intubation vs nonintubated patients	OR 1.53 (CI 1.15 to 1.86)
Winchell RJ, Hoyt DB 1997 USA	All trauma patients admitted to trauma centres in San Diego county from 1991-1995 who underwent field intubation when GCS <=8(565 were intubated and 527 were not intubated in field)	Retrospective registry based review	Scene GCS scores in intubated and non-intubated groups	No difference	Retrospective design, matching may have have left out several critical parameters, multivariate analysis not done, functional outcomes not compared
			Mortality in patients who were not intubated for whole group	36% versus 26% OR 1.6
			Mortality in patients not intubated with isolated severe head injruy	49.6% versus 22.8% OR 3
Davis DP et al, 2005 USA	13, 625 patients with moderate to severe traumatic brain injury included on a country trauma registry of whom 19.3% were intubated in the prehospital environment	Observational	Mortality	Increased with prehospital intubation (OR 0.36 p<0.001)

Comment(s)

Quite a few studies have been conducted to address the question of prehospital endotracheal intubation in major trauma victims needing airway management. All of them are of retrospective design and most of them show that there is increased mortality, longer transit times with prehospital endotracheal intubation. The reasons could be difficulty in ascertaining tube position, paramedic experience, hyperventilation, transient hypoxia, or lack of sufficient pre-oxygenation prior to RSI. Prospective multi-centre randomised trials are needed to avoid the inherent problems associated with the study designs.

Clinical Bottom Line

Prehospital endotracheal intubation is associated with increased mortality in patients with moderate to severe traumatic brain injury

References

1. Wang HE, Peitzman AB, Cassidy LD, Adelson PD, Yealy DM. Out-of-hospital Endotracheal Intubation and outcome after traumatic brain injury. Annals of Emergency Medicine 44(5):439-50, 2004 Nov.
2. Stockinger ZT, McSwain NE Jr. Prehospital Endotracheal intubation for trauma does not improve survival over bag-valve-mask ventilation. Journal of Trauma, Injury Infection & Critical Care 56(3):531-6, 2004 Mar.
3. Davis DP, Hoyt DB, Ochs M, Fortlage D, Holbrook T, Marshall LK, Rosen P. The effect of paramedic rapid sequence intubation on outcome in patients with severe traumatic head injury. Journal of Trauma, Injury, Infection and Critical Care 54(3):444-53, 2003 Mar.
4. Bochichhio GV, Ilahi O, Joshi M, Bochicchio K, Scalea TM. Endotracheal Intubation in the field does not improve outcome in trauma patients who present without an acutely lethal traumatic brain injury. Journal of Trauma, Injury, Infection and Critical Care 2003;54:307-311.
5. Sloane C, Vilke GM, Chan TC, Hayden SR, Hoyt DB, Rosen P. Rapid Sequence Intubation in the field versus hospital in trauma patients. Journal of Emergency Medicine 2000:vol 19;3:259-264.
6. Eckstein M, Chan L, Schneir A, Palmer R. Effect of prehospital advanced life support on outcomes of major trauma patients. Journal of Trauma, Injury, Infection and Critical Care 48(4):643-8, 2000 Apr.
7. Murray JA, Demetriades D, Berne TV, Stratton Sj, Cryer HG, Bongard F, Fleming A, Gaspard D. Prehospital intubation in patients with severe head injury. Journal of Trauma,Injury,Infection and Critical Care 2000;49:1065-1070.
8. Winchell RJ, Hoyt DB. Endotracheal intubation in the field improves survival in patients with severe head injury. Archives of Surgery 1997;132:592-597.
9. Davis DP, Peay J, Sise MJ. et al. The impact of prehospital endotgracheal intubation on outcome in moderate to severe traumatic brain injury. J Trauma Infect Crit Care 2005;58:933–9.