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/year | Level of evidence (bias code) | Study design | Summary |
|---|---|---|---|
| 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 |
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.