Table 1

 In the adult with potential cervical spine injury requiring emergency intubation in the resuscitation room, what is the optimal method to achieve a secure airway? Evidence from systematic reviews of the literature

Author/yearLevel of evidence (bias code)Study designSummary
c-spine, cervical spine; ED, emergency department; ETT, endotracheal tube; iLMA, intubating laryngeal mask airway; LMA, laryngeal mask airway; MILS, manual in-line stabilisation; RSI, rapid sequence induction and intubation.
Brimacombe 199527I (a)Meta analysis of studies studying risk of aspiration with LMA. Not specific to trauma, most studies are elective patient studies with data collected up to 1993LMA adequate for low risk patients treated with caution
Asai 200084II (a)Randomised clinical trial; 124 elective patients. 40 had MILS and cricoid and 84 patients had no spinal precautions. They underwent fibreoptic intubation +/− iLMA. Faster and easier intubation when iLMA used with fibrescope. Excluded Mallampati 3&4Fibreoptic intubation facilitated by iLMA when MILS and cricoid employed better than fibreoptic alone
Brimacombe 199356II (a)Randomised clinical trial; 80 elective pts LMA +/− MILSLMA with MILS 95% correct placement v 100% without MILS
Brimacombe 200082II (a)Randomised crossover on 10 cadavers with destabilised C3 and MILS. Tested for degree of c-spine movement with face mask ventilation, orotracheal intubation, fibreoptic nasal ETT, combitube, iLMA, LMA. But how much c-spine movement is significant? Extrapolation of simulated views to trauma is unknownFibrescope nasal ETT causes least displacement of the c-spine. Face mask ventilation displaced c-spine the same as LMA/iLMA. LMA causes less movement than combitube
Gerling 200043II (a)Randomised crossover on 14 cadavers with C5–6 transection intubated with either MILS or hard cervical collar, sandbags, and tape. Movement of c-spine recordedMILS better than sandbags and tape
Keller 199988II (a)Randomised crossover trial on 20 cadavers comparing iLMA & LMA with ETT. Pharyngeal pressures and c-spine movement measured. No neck stabilisation employedLMA and iLMA exert more pressure and displacement than ETT on c-spine. Laryngeal mask only recommended if difficulties are expected or encountered with ETT
Nolan 199349II (a)Randomised clinical trial; 157 elective patients compared using ETT alone or with bougie when MILS/cricoid in place. Laryngoscopy view reduced in 45% pts when MILS and cricoid applied. Bougie increased rate of successful intubationsGum elastic bougie recommended as aid to intubation
Pennant 199341II (a)Randomised crossover trial; 28 elective patients comparing ETT and LMA. Hard cervical collar in situ. No MILS applied. Not trauma patientsHard collar reduces mouth opening by 60%. LMA faster and easier than ETT but does not protect against aspiration so recommended only when ETT fails
Smith 199983II (a)Randomised clinical trial; 87 elective patients comparing fibrescope and direct laryngoscopy. MILS in situ. Excluded Mallampati 3&4Fibrescope gave comparable rates of successful intubations to direct laryngoscopy. Fibrescope needs training and not commonly available
Waltl 200157II (a)Randomised clinical trial; 40 elective patients comparing direct laryngoscopy and iLMA. C-spine not immobilised. x Rays used to assess c-spine movement. Success rate with ETT 100%, iLMA 92%. iLMA slower but caused less movement at C1,2Direct laryngoscopy was the fastest way to secure an uncomplicated airway. iLMA is a viable alternative
Watts 199752II (a)Randomised crossover; 29 elective patients intubated with Bullard and Macintosh scopes, with and without MILS/cricoid. Bullard resulted in less cervical extension but had prolonged time to intubation. Bullard scope not commonly availableMacintosh faster but slightly poorer views. Rate of first intubations comparable with Bullard scope
Gataure 199648II (b1)Randomised clinical trial; 100 elective pts with simulated grade 3 views glottis intubated with aid of stylet or flexible bougieBougie got higher success rates intubation than stylet (96% v 66% in 2 attempts)
Carley 200053II (b2)Short cut review; McCoy v Macintosh for best view of cords; McCoy better views of cords. Medline search onlyMcCoy better than MacIntosh to view cords when C-spine is immobile
Carley 200150II (b2)Short cut review finding one relevant paper about the Gum elastic bougie in difficult intubation (Nolan 1993).49 Medline search onlyGum elastic bougie facilitates intubation
Inoue 200285II (b2)Randomised clinical trial; 148 patients for c-spine surgery light wand or iLMA with neck in neutral position. Bias possible as 7.5% patients excluded. Why?Light wand success 97.3% and faster, iLMA 73% success (using fibrescope when needed)
Jones 200251II (b2)Short cut review; Bougie or stylet in simulated grade 3 intubations. Medline search onlyBougie faster and higher success rate than stylet
MacIntyre 199954III-1 (a)Randomised crossover; 10 elective pts. MacIntosh compared with McCoy laryngoscope, hard collar in situ. C-spine movement assessed on x ray. Unable to blind staff and 4/10 cases had problems with x raysGreatest movement at C1–2 with no significant difference between laryngoscopes
Donaldson 199747III-2 (a)Non-randomised crossover cadaver study. 6 cadavers assessed for c-spine movement on simple airway manoeuvres, intubation orally and nasally with MILS in situ—pre and post C1–2 osteotomyc-spine movement with chin lift and jaw thrust noted. No advantage for nasal intubation shown on amount of c-spine movement
Lennarson 200144III-2 (a)Non-randomised crossover on 10 cadavers +/− C4,5 destabilisation. Movement examined with no c-spine stabilisation, MILS, or Gardner-Wells tractionMILS shown as the best method to minimise c-spine movement for ETT. Traction caused excess distraction
Majernick 198645III-2 (a)Non-randomised clinical trial; 16 elective patients comparing c-spine movement at intubation with either no c-spine immobilisation or hard cervical collar or MILS. Unable to blind staff. Not randomised into groups. Small numbersMILS gives least movement during intubation
Heath 199446III-2 (b1)Non-randomised crossover; 50 elective patients intubated with no immobilisation, MILS, or sandbags and tape. Mallampatti grade 3/4 in 64% with sandbags v 22% using MILS66% had better scope views with MILS rather than sandbags/tape. Poor mouth opening noted when wearing collar
Donaldson 199389III-2 (b2)Non-randomised crossover trial on 5 cadavers with and without destabilisation at C5–6. Assessed for c-spine movement with chin lift/jaw thrust, cricoid pressure, ETT +/− MILS, nasal ETT, and tracheostomy. MILS not employed throughoutAll techniques move c-spine including simple airway manoeuvres
Sakles 199821IV (b1)Prospective review of tracheal intubations in the ED (47.7% trauma); RSI used in 89.9% with success in 99.2%. Success rate in those intubated without neuromuscular blockade was 91.5%RSI preferred technique for intubation
Criswell 19944IV (b2)Retrospective review of patients with spinal injuries requiring intubation at trauma centre. 73 patients intubated using RSI, cricoid, and MILS with no neurological sequelaeRSI safe and preferred method with potential spinal injuries
Konishi 199790 abstract onlyComparison of c-spine movement using McCoy, Macintosh, and Miller laryngoscopes at intubationMcCoy caused least c-spine movement