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/year | Level of evidence (bias code) | Study design | Summary |
|---|---|---|---|
| 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 199527 | I (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 1993 | LMA adequate for low risk patients treated with caution |
| Asai 200084 | II (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&4 | Fibreoptic intubation facilitated by iLMA when MILS and cricoid employed better than fibreoptic alone |
| Brimacombe 199356 | II (a) | Randomised clinical trial; 80 elective pts LMA +/− MILS | LMA with MILS 95% correct placement v 100% without MILS |
| Brimacombe 200082 | II (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 unknown | Fibrescope 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 200043 | II (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 recorded | MILS better than sandbags and tape |
| Keller 199988 | II (a) | Randomised crossover trial on 20 cadavers comparing iLMA & LMA with ETT. Pharyngeal pressures and c-spine movement measured. No neck stabilisation employed | LMA 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 199349 | II (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 intubations | Gum elastic bougie recommended as aid to intubation |
| Pennant 199341 | II (a) | Randomised crossover trial; 28 elective patients comparing ETT and LMA. Hard cervical collar in situ. No MILS applied. Not trauma patients | Hard 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 199983 | II (a) | Randomised clinical trial; 87 elective patients comparing fibrescope and direct laryngoscopy. MILS in situ. Excluded Mallampati 3&4 | Fibrescope gave comparable rates of successful intubations to direct laryngoscopy. Fibrescope needs training and not commonly available |
| Waltl 200157 | II (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 C1,2 | Direct laryngoscopy was the fastest way to secure an uncomplicated airway. iLMA is a viable alternative |
| Watts 199752 | II (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 available | Macintosh faster but slightly poorer views. Rate of first intubations comparable with Bullard scope |
| Gataure 199648 | II (b1) | Randomised clinical trial; 100 elective pts with simulated grade 3 views glottis intubated with aid of stylet or flexible bougie | Bougie got higher success rates intubation than stylet (96% v 66% in 2 attempts) |
| Carley 200053 | II (b2) | Short cut review; McCoy v Macintosh for best view of cords; McCoy better views of cords. Medline search only | McCoy better than MacIntosh to view cords when C-spine is immobile |
| Carley 200150 | II (b2) | Short cut review finding one relevant paper about the Gum elastic bougie in difficult intubation (Nolan 1993).49 Medline search only | Gum elastic bougie facilitates intubation |
| Inoue 200285 | II (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 200251 | II (b2) | Short cut review; Bougie or stylet in simulated grade 3 intubations. Medline search only | Bougie faster and higher success rate than stylet |
| MacIntyre 199954 | III-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 rays | Greatest movement at C1–2 with no significant difference between laryngoscopes |
| Donaldson 199747 | III-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 osteotomy | c-spine movement with chin lift and jaw thrust noted. No advantage for nasal intubation shown on amount of c-spine movement |
| Lennarson 200144 | III-2 (a) | Non-randomised crossover on 10 cadavers +/− C4,5 destabilisation. Movement examined with no c-spine stabilisation, MILS, or Gardner-Wells traction | MILS shown as the best method to minimise c-spine movement for ETT. Traction caused excess distraction |
| Majernick 198645 | III-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 numbers | MILS gives least movement during intubation |
| Heath 199446 | III-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 MILS | 66% had better scope views with MILS rather than sandbags/tape. Poor mouth opening noted when wearing collar |
| Donaldson 199389 | III-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 throughout | All techniques move c-spine including simple airway manoeuvres |
| Sakles 199821 | IV (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 19944 | IV (b2) | Retrospective review of patients with spinal injuries requiring intubation at trauma centre. 73 patients intubated using RSI, cricoid, and MILS with no neurological sequelae | RSI safe and preferred method with potential spinal injuries |
| Konishi 199790 abstract only | Comparison of c-spine movement using McCoy, Macintosh, and Miller laryngoscopes at intubation | McCoy caused least c-spine movement | |