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Intubation with cervical spine immobilisation

2018; Lippincott Williams & Wilkins; Volume: 35; Issue: 5 Linguagem: Inglês

10.1097/eja.0000000000000693

1365-2346

Dawid Aleksandrowicz, Andrzej Wieczorek, Tomasz Gaszyński,

Respiratory Support and Mechanisms

Editor, The management of acute spinal cord injury is a multidisciplinary effort.1 Therefore, the care pathway of trauma patients should emphasise prevention of secondary injuries to the cervical spine in particular. Tracheal intubation with simultaneous immobilisation of the cervical spine is the recommended airway management strategy in cases of respiratory failure in trauma patients.2 Inadequate immobilisation of the neck during intubation may result in a poor neurological outcome. But it should be appreciated that application of manual in-line stabilisation (MILS) may significantly worsen laryngoscopic conditions and make intubation with the standard Macintosh laryngoscope difficult. New airway management devices may be of benefit in such conditions, although more studies are required to fully evaluate their real value and performance. The KingVision is a new videolaryngoscope that incorporates a series of lenses, a camera with a source of light, and a small monitor. It has single-use blades with or without a guiding channel for the tracheal tube. Current reports provide limited information on its performance during intubation with cervical spine immobilisation. We hypothesised that the KingVision may shorten intubation time and improve the success rate of intubation of patients with reduced cervical spine mobility. The aim of this study was to assess the performance of the KingVision videolaryngoscope with a channelled blade in a clinical scenario. The current study was approved by the Medical University of Łódź Ethics Committee (Protocol number: RNN/363/13/KB; 21 May 2013). Ten senior (consultant) anaesthetists participated in this study. Their experience varied between 6 and 10 years of clinical practice after completion of anaesthetic training. All patients who took part in the study were undergoing elective surgical procedures. Written informed consent was obtained from all patients before the study. Our study included patients with grades 1 and 2 of the American Society of Anesthesiologists physical status. The semi-rigid cervical collar (Össur hf., Reykjavik, Iceland) was correctly sized and fitted according to the manufacturer instructions in all patients before induction of anaesthesia.3 None of the patients had predictors of a difficult airway. A total of 40 patients were randomised into two groups with 20 patients in each group: Group I (the Macintosh laryngoscope) and Group II (the KingVision videolaryngoscope). Standard monitoring in the operating theatre consisted of electrocardiography, non-invasive blood pressure, pulse-oxymetry, capnography, volatile anaesthetic concentration and the depth of the neuromuscular block. Anaesthesia was induced with fentanyl 1 to 2 μg kg−1 and propofol 2 to 3 mg kg−1. Neuromuscular block was achieved with rocuronium 0.6 mg kg−1. The tracheal tube size used for intubation was 7.5 mm for women and 8.0 mm for men. Both the pillow and the anterior part of the cervical collar were removed just before laryngoscopy and MILS was applied by a trained assistant and maintained during the intubation attempts. The two intubation devices compared were the Macintosh laryngoscope (New Waseem Trading, Sialkot, Pakistan) and the KingVision videolaryngoscope with a channelled blade (King Systems, Noblesville, Indiana, USA). The randomisation scheme involved the use of 10 variable digit tables prepared before the study with a 50% chance of selecting either device as the first one for study. A maximum of two intubation attempts with the evaluated devices was permitted. The time of intubation was measured from the beginning of the procedure until the tube was placed in the trachea and the intubation device was removed. Data were subjected to statistical analysis with Microsoft Office Excel 2010 spreadsheet (Microsoft Corporation, Redmond, WA, USA) and Statistica 10 software (StatSoft Inc, Tulsa, OK, USA). The mean (SD) intubation time for the KingVision videolaryngoscope was 9.8 (2.68) and 12.2 (3.71) s for the Macintosh, respectively, P = 0.0001. There was a 100% intubation success rate with the KingVision videolaryngoscope compared with 75% for the Macintosh, P = 0.0004, and no additional manoeuvres were required in the KingVision group. The Backward, Upward, Rightward Pressure manoeuvre was required in 40% (eight out of 20) of intubation attempts with the Macintosh (P < 0.0001 compared with the KingVision). Adequate airway management in patients with life-threatening injuries in out-of-hospital settings is associated with an increased survival rate and reduction in complications such as hypoxia.4 There are many current studies that show that the new airway devices such as videolaryngoscopes enable faster and safer intubation when compared with the classic Macintosh laryngoscope.5 The one exception may be a study by Wetsch et al.6 who showed that the Macintosh outperformed videolaryngoscopes when used by experienced anaesthetists in a scenario involving entrapped patients. In contrast, Jain et al.7, in their manikin study, noted that the use of the Camera-Macintosh (C-MAC) videolaryngoscope was associated with better glottic visualisation compared with the Macintosh and McCoy laryngoscopes in simulated difficult airways. Furthermore, the C-MAC videolaryngoscope enabled faster intubation with an increased success rate at the first attempt. This was also noted in our study. Shravanalakshmi et al.8 evaluated various videolaryngoscopes in patients with cervical spine injury. The intubation times were faster with the C-MAC device when compared with the KingVision. The results of this study support the use of videolaryngoscopes in patients with cervical spine injury. The results of a manikin study by Murphy et al. showed that intubation performed by paramedics was 3.4 s faster with the KingVision when compared with the Macintosh and 11.3 s faster in a difficult airway scenario in cadavers. Furthermore, in that scenario, there were no failed intubation attempts when the KingVision was used.9 Similar results were observed in our study. The ability to visualise the laryngeal inlet plays an important role and a better glottic view is associated with a shorter mean intubation time when cervical spine mobility is reduced. The results of our study show that the use of the KingVision is associated with a shorter intubation time. Furthermore, during its use for intubation, no additional manoeuvres were required to facilitate tracheal tube placement. Acknowledgements relating to this article Assistance with the study: none. Financial support and sponsorship: none. Conflicts of interest: none.