Videolaryngoscopy vs. Macintosh laryngoscopy for double‐lumen tube intubation in thoracic surgery: a systematic review and meta‐analysis

Double‐lumen intubation is more difficult than single‐lumen tracheal intubation. Videolaryngoscopes have many advantages in airway management. However, the advantages of videolaryngoscopy for intubation with a double‐lumen tube remain controversial compared with traditional Macintosh laryngoscopy. In this study, we searched MEDLINE, Embase, Cochrane Library and the Web of Science for randomised controlled trials comparing videolaryngoscopy with Macintosh laryngoscopy for double‐lumen tube intubation. We found that videolaryngoscopy provided a higher success rate at first attempt for double‐lumen tube intubation, with an odds ratio (95%CI) of 2.77 (1.92–4.00) (12 studies, 1215 patients, moderate‐quality evidence, p < 0.00001), as well as a lower incidence of oral, mucosal or dental injuries during double‐lumen tube intubation, odds ratio (95%CI) 0.36 (0.15–0.85) (11 studies, 1145 patients, low‐quality evidence, p = 0.02), and for postoperative sore throat, odds ratio (95%CI) 0.54 (0.36–0.81) (7 studies, 561 patients, moderate‐quality evidence, p = 0.003), compared with Macintosh laryngoscopy. There were no significant differences in intubation time, with a standardised mean difference (95%CI) of ?0.10 (?0.62 to 0.42) (14 studies, 1310 patients, very low‐quality evidence, p = 0.71); and the incidence of postoperative voice change, odds ratio (95%CI) 0.53 (0.21–1.31) (7 studies, 535 patients, low‐quality evidence, p = 0.17). Videolaryngoscopy led to a higher incidence of malpositioned double‐lumen tube, with an odds ratio (95%CI) of 2.23 (1.10–4.52) (six studies, 487 patients, moderate‐quality evidence, p = 0.03).     

Videolaryngoscopy vs. fibreoptic bronchoscopy for awake tracheal intubation: a systematic review and meta‐analysis

Awake fibreoptic intubation is often considered the technique of choice when a difficult airway is anticipated. However, videolaryngoscopes are being used more commonly. We searched the current literature and performed a meta‐analysis to compare the use of videolaryngoscopy and fibreoptic bronchoscopy for awake tracheal intubation. Our primary outcome was the time needed to intubate the patient's trachea. Secondary outcomes included: failed intubation; the rate of successful intubation at the first attempt; patient‐reported satisfaction with the technique; and any complications resulting from intubation. Eight studies examining 429 patients were included in this review. The intubation time was shorter when videolaryngoscopy was used instead of fibreoptic bronchoscopy (seven trials, 408 participants, mean difference (95%CI) ?45.7 (?66.0 to ?25.4) s, p < 0.0001, low‐quality evidence). There was no significant difference between the two techniques in the failure rate (six studies, 355 participants, risk ratio (95%CI) 1.01 (0.24–4.35), p = 0.99, low‐quality evidence) or the first‐attempt success rate (six studies, 391 participants, risk ratio (95%CI) 1.01 (0.95–1.06), p = 0.8, moderate quality evidence). The level of patient satisfaction was similar between both groups. No difference was found in two reported adverse events: hoarseness/sore throat (three studies, 167 participants, risk ratio (95%CI) 1.07 (0.62–1.85), p = 0.81, low‐quality evidence), and low oxygen saturation (five studies, 337 participants, risk ratio (95%CI) 0.49 (0.22–1.12), p = 0.09, low‐quality evidence). In summary, videolaryngoscopy for awake tracheal intubation is associated with a shorter intubation time. It also seems to have a success rate and safety profile comparable to fibreoptic bronchoscopy.     

Videolaryngoscopy vs. direct Macintosh laryngoscopy in tracheal intubation in adults: a ranking systematic review and network meta-analysis

Videolaryngoscopes are thought to improve glottic view and facilitate tracheal intubation compared with the Macintosh direct laryngoscope. However, we currently do not know which one would be the best choice in most patients undergoing anaesthesia. We designed this systematic review with network meta-analyses to rank the different videolaryngoscopes and the Macintosh direct laryngoscope. We conducted searches in PubMed and a further five databases on 11 January 2021. We included randomised clinical trials with patients aged ≥16 years, comparing different videolaryngoscopes, or videolaryngoscopes with the Macintosh direct laryngoscope for the outcomes: failed intubation; failed first intubation attempt; failed intubation within two attempts; difficult intubation; percentage of glottic opening seen; difficult laryngoscopy; and time needed for intubation. We assessed the quality of evidence according to GRADE recommendations and included 179 studies in the meta-analyses. The C-MAC and C-MAC D-Blade were top ranked for avoiding failed intubation, but we did not find statistically significant differences between any two distinct videolaryngoscopes for this outcome. Further, the C-MAC D-Blade performed significantly better than the C-MAC Macintosh blade for difficult laryngoscopy. We found statistically significant differences between the laryngoscopes for time to intubation, but these differences were not considered clinically relevant. The evidence was judged as of low or very low quality overall. In conclusion, different videolaryngoscopes have differential intubation performance and some may be currently preferred among the available devices. Furthermore, videolaryngoscopes and the Macintosh direct laryngoscope may be considered clinically equivalent for the time taken for tracheal intubation. However, despite the rankings from our analyses, the current available evidence is not sufficient to ensure significant superiority of one device or a small set of them over the others for our intubation-related outcomes.     

Tracheal intubation of morbidly obese patients: LMA CTrach vs direct laryngoscopy

Background. LMA CTrach^TM (CT), a modified version of the intubatingLMA Fastrach^TM, allows continuous video-endoscopy of the trachealintubation procedure. We tested the hypothesis that the CT isefficient for tracheal intubation of morbidly obese patientswho are at risk of a difficult airway. Methods. After Ethics’ Committee approval, 104 morbidlyobese patients (BMI >35 kg m^–2) scheduled for bariatricsurgery were included in this prospective study. Patients wererandomly assigned in two groups: tracheal intubation using directlaryngoscopy (DL) or the CT. Induction of anaesthesia was standardizedusing sufentanil, propofol and succinylcholine. Characteristicsand consequences of airway management were evaluated. Results. Preoperative characteristics of patients and consequencesof anaesthesia induction on physiological variables were similarin both groups. Difficulty in facemask ventilation was similarin both groups. Tracheal intubation was successfully carriedout with DL and CT. Forty-nine per cent of the patients fromthe CT group required laryngeal mask manipulation (ventilationand view optimization) resulting in increased duration of trachealintubation by 57 s as compared with DL. Oxygenation was of betterquality in the patients managed with CT than with DL. Blindtracheal intubation was mandatory in eight (17%) patients ofthe DL group, while tracheal intubation was seen in all patientsof the CT group. Conclusion. We demonstrated that the CT was an efficient airwaydevice for ventilation and tracheal intubation in case of adifficult airway in morbidly obese patients.      

Videolaryngoscopy vs. flexible fibrescopy for tracheal intubation in patients with cervical spine immobilisation: a randomised controlled trial

In patients with cervical spine immobilisation, tracheal intubation devices other than a direct laryngoscope are frequently used to facilitate tracheal intubation and avoid related complications. In this randomised controlled trial, we compared videolaryngoscopic and fibrescopic tracheal intubation in patients with a cervical collar. Tracheal intubation was performed using either a videolaryngoscope with a non-channelled Macintosh blade (n = 166) or a flexible fibrescope (n = 164) in patients having elective cervical spine surgery whose neck was immobilised with a cervical collar to simulate a difficult airway. The primary outcome was the first attempt success rate of tracheal intubation. Secondary outcomes were the overall success rate of tracheal intubation; time to tracheal intubation; use of additional airway manoeuvres; and incidence and severity of tracheal intubation-related airway complications. First attempt success rate was higher in the videolaryngoscope group than in the fibrescope group (164/166 (98.8%) vs. 149/164 (90.9%), p = 0.003). Tracheal intubation was successful within three attempts in all patients. Median (IQR [range]) time to tracheal intubation was shorter (50.0 (41.0–72.0 [25.0–170.0]) s vs. 81.0 (65.0–107.0 [24.0–178.0]) s, p < 0.001) and additional airway manoeuvres were less frequent (30/166 (18.1%) vs. 91/164 (55.5%), p < 0.001) in the videolaryngoscope group compared with the fibrescope group. The incidence and severity of intubation-related airway complications were not different between the two groups. When performing tracheal intubation in patients with a cervical collar, videolaryngoscopy with a non-channelled Macintosh blade was superior to flexible fibrescopy.     

A comparison of bonfils fiberscope‐assisted laryngoscopy and standard direct laryngoscopy in simulated difficult pediatric intubation: a manikin study

Introduction: Difficult airway management in children is challenging. One alternative device to the gold standard of direct laryngoscopy is the STORZ Bonfils fiberscope (Karl Storz Endoscopy, Tuttlingen, Germany), a rigid fiberoptic stylette‐like scope with a curved tip. Although results in adults have been encouraging, reports regarding its use in children have been conflicting. We compared the effectiveness of a standard laryngoscope to the Bonfils fiberscope in a simulated difficult infant airway. Methods: Ten pediatric anesthesiologists were recruited for this study and asked to perform three sets of tasks. For the first task, each participant intubated an unaltered manikin (SimBaby ^TM, Laerdal, Puchheim, Germany) five times using a styletted 3.5 endotracheal tube (ETT) and a Miller 1 blade (group DL‐Normal). For the second task, a difficult airway configuration simulating a Cormack‐Lehane grade 3B view was created by fixing a Miller‐1 blade into position in the manikin using a laboratory stand. Each participant then intubated the manikin five times with a styletted 3.5 ETT using conventional technique but without touching the laryngoscope (group DL‐Difficult). In the third task, the manikin was kept in the same difficult airway configuration, and each participant intubated the manikin five times using a 3.5‐mm ETT mounted on the Bonfils fiberscope as an adjunct to direct laryngoscopy with the Miller‐1 blade (group BF‐Difficult). Primary outcomes were time to intubate and success rate. Results: A total of 150 intubations were performed. Correct ETT placement was achieved in 100% of attempts in group DL‐Normal, 90% of attempts in group DL‐Difficult and 98% of attempts in BF‐Difficult. Time to intubate averaged 14 s (interquartile range 12–16) in group DL‐Normal; 12 s (10–15) in group DL‐Difficult; and 11 s (10–18) in group BF‐Difficult. The percentage of glottic opening seen (POGO score) was 70% (70–80) in group DL‐Normal; 0% (0–0) in group DL‐Difficult; and 100% (100–100) in group BF‐Difficult. Discussion: The Bonfils fiberscope‐assisted laryngoscopy was easier to use and provided a better view of the larynx than simple direct laryngoscopy in the simulated difficult pediatric airway, but intubation success rate and time to intubate were not improved. Further studies of the Bonfils fibrescope as a pediatric airway adjunct are needed.     

Videolaryngoscopy versus direct laryngoscopy for emergency orotracheal intubation outside the operating room: a systematic review and meta-analysis

Videolaryngoscopy (VL) may improve the success of orotracheal intubation compared with direct laryngoscopy (DL). We performed a systematic search of PubMed, Embase, and CENTRAL databases for studies comparing VL and DL for emergency orotracheal intubations outside the operating room. The primary outcome was rate of first-pass intubation, with subgroup analyses by location, device used, clinician experience, and clinical scenario. The secondary outcome was complication rates. Data are presented as [odds ratio (95% confidence intervals); P-values]. We identified 32 studies with 15 064 emergency intubations. There was no difference in first-pass intubation with VL compared with DL [OR=1.28, (0.99–1.65); P=0.06]. First-pass intubations were increased with VL compared with DL in the intensive care unit (ICU) [2.02 (1.43–2.85); P<0.001], and similar in the emergency department or pre-hospital setting. First-pass intubations were similar with GlideScope^®, but improved with the CMAC^® [1.32 (1.08–1.62); P=0.007] compared with DL. There was greater first-pass intubation with VL compared with DL amongst novice/trainee clinicians [OR=1.95 (1.45–2.64); P<0.001], but not amongst experienced clinicians or paramedics/nurses. There was no difference in first-pass intubation with VL compared with DL during cardiopulmonary resuscitation or trauma. VL compared with DL was associated with fewer oesophageal intubations [OR=0.32 (0.14–0.70); P=0.003], but more arterial hypotension [OR=1.49 (1.00–2.23); P=0.05]. In summary, VL compared with DL is associated with greater first-pass emergency intubation in the ICU and amongst less experienced clinicians, and reduces oesophageal intubations. However, VL is associated with greater incidence of arterial hypotension. Further trials investigating the utility of VL over DL in specific situations are required.     

Impact of direct laryngoscopy vs. videolaryngoscopy on signal quality of recurrent laryngeal nerve monitoring in thyroid surgery: a randomised parallel group trial

In thyroid surgery, intra-operative neuromonitoring signals of the recurrent laryngeal nerve can be detected by surface electrodes on a tracheal tube positioned at the vocal fold level. The incidence of difficult tracheal intubation in patients undergoing thyroidectomy for nodular goitre ranges from 5.3% to 20.5%. The aim of this study was to compare videolaryngoscopy with conventional direct laryngoscopy as methods for proper placement of the surface electrode to prevent insufficient intra-operative nerve signal quality. In this prospective randomised trial, adult patients requiring tracheal intubation during thyroid surgery were randomly allocated to two groups of C-MAC^® (Macintosh style blade) videolaryngoscope or direct laryngoscopy using the Macintosh laryngoscope. Primary outcome was the incidence of insufficient signal electromyogram amplitude level (< 500 μV) after successful tracheal intubation. A total of 260 (130 per group) participants were analysed. An insufficient signal was more frequent with direct laryngoscopy (35/130, 27%), compared with C-MAC (12/130, 9%, p < 0.001). First-pass tracheal intubation success rate was lower with direct laryngoscopy (86/130 (66%)) compared with the C-MAC (125/130 (96%)) (p < 0.0001). Cormack and Lehane grade ≥ 3 was observed more frequently with direct laryngoscopy (16/130 (12%)), compared with the C-MAC (0/130, (0%)) (p < 0.0001). The results suggest that videolaryngoscopy has an impact on the quality of the initial intra-operative neuromonitoring signal in patients undergoing thyroid surgery, and this technique can provide optimised surface electrode positioning.     

An assessment of the tolerability of the Cook staged extubation wire in patients with known or suspected difficult airways extubated in intensive care

The Cook staged extubation set (Cook Medical) has been developed to facilitate management of the difficult airway. A guidewire inserted before tracheal extubation provides access to the subglottic airway should re‐intubation be required. This prospective cohort study examines patients’ tolerance of the guidewire and its impact on clinical status around tracheal extubation in the intensive care unit. Vital signs, incidence of symptoms and patient tolerance of the wire were recorded. Twenty‐three patients were enrolled and 17 (73%) tolerated the wire for 4 h. Nasendoscopy was performed in 11 of these patients and revealed one wire was in the oesophagus. The most common symptom was a mild intermittent cough in 13 patients. There was no impact of the guidewire on nursing care in 16 patients, tolerable impact in five and severe impact necessitating removal of the wire in one patient.     

Effect of palpable vs. impalpable cricothyroid membranes in a simulated emergency front‐of‐neck access scenario

The Difficult Airway Society 2015 guidelines recommend and describe in detail a surgical cricothyroidotomy technique for the can't intubate, can't oxygenate (CICO) scenario, but this can be technically challenging for anaesthetists with no surgical training. Following a structured training session, 104 anaesthetists took part individually in a simulated can't intubate, can't oxygenate event using simulation and airway models to evaluate how well they could perform these front‐of‐neck access techniques. Main outcomes measures were: ability to correctly perform the technical steps; procedural time; and success rate. Outcomes were compared between palpable and impalpable cricothyroid membrane scenarios. Anaesthetists’ technical abilities were good, as assessed by a video analysis checklist score. Mean (SD) procedural time was 44 (16) s and 65 (17) s for the palpable and impalpable cricothyroid membrane models, respectively (p ≤ 0.001). First‐pass tracheal tube placement was obtained in 103 out of the 104 palpable cricothyroidotomies and in 101 out of the 104 impalpable cricothyroidotomies (p = 0.31). We conclude that anaesthetists can be trained to perform surgical front‐of‐neck access to an acceptable level of competence and speed when assessed using a simulator.     

Comparison of the Cobalt Glidescope® video laryngoscope with conventional laryngoscopy in simulated normal and difficult infant airways*

Aim: To evaluate the new pediatric Glidescope^® (Cobalt GVL^® Stat) by assessing the time taken to tracheal intubation under normal and difficult intubation conditions. We hypothesized that the Glidescope^® would perform as well as conventional laryngoscopy. Background: A new pediatric Glidescope^® became available in October 2008. It combines a disposable, sterile laryngoscope blade and a reusable video baton. It is narrower and longer than the previous version and is available in a greater range of sizes more appropriate to pediatric use. Methods: We performed a randomized study of 32 pediatric anesthetists and intensivists to compare the Cobalt GVL^® Stat with the Miller laryngoscope under simulated normal and difficult airway conditions in a pediatric manikin. Results: We found no difference in time taken to tracheal intubation using the Glidescope^® or Miller laryngoscope under normal (29.3 vs 26.2 s, P = 0.36) or difficult (45.8 and 44.4 s, P = 0.84) conditions. Subjective evaluation of devices for field of view (excellent: 59% vs 53%) and ease of use (excellent: 69% vs 63%) was similar for the Miller laryngoscope and Glidescope^®, respectively. However, only 34% of participants said that they would definitely use the Glidescope^® in an emergency compared with 66% who would be willing to use the Miller laryngoscope. Conclusions: The new Glidescope^® performs as well as the Miller laryngoscope under simulated normal and difficult airway conditions.     

Evaluation of three unchannelled videolaryngoscopes and the Macintosh laryngoscope in patients with a simulated difficult airway: a randomised,controlled trial

This prospective randomised, controlled trial compares the performance of three unchannelled videolaryngoscopes (KingVision^?, Airtraq^?, A.P. Advance^? MAC ) and the standard Macintosh laryngoscope. With ethics committee approval and written informed consent, 480 patients were included. A difficult airway was created with a cervical collar, limiting mouth opening and neck movement. Primary outcome was first‐attempt orotracheal intubation success. Overall success, laryngeal view, intubation difficulty scale, handling, intubation times and side‐effects were secondary outcomes. First‐attempt success rates were: KingVision 90% (95% CI 83–94%), Airtraq 82% (74–88%), A.P. Advance MAC 49% (40–58%), Macintosh 44% (35–53%; p < 0.001). The 95% confidence interval of first‐attempt success rate was thus below 90% for all devices, but the KingVision and the Airtraq performed better than the A.P. Advance MAC and the Macintosh laryngoscope. Also, performance was better with the KingVision and the Airtraq in terms of overall success, laryngeal view, intubation difficulty scale and quality of view. Problems with tube advancement were a frequent cause of intubation failure. In summary, the KingVision and the Airtraq performed better than the A.P. Advance MAC and the Macintosh laryngoscope. Success rates of the unchannelled KingVision and Airtraq were similar to those of their channelled versions reported previously, indicating that performance largely depends on blade design rather than the presence of a channel for tube advancement.     

Laparoscopic partial nephrectomy in obese patients: a systematic review and meta‐analysis

What's known on the subject? and What does the study add? The literature yielded only four studies on the subject; however, no clear outcome can be taken from individual studies. This review adds a meta‐analysis of these four studies to make the patient cohort larger and to allow for a greater understanding of the procedure in this select group of patients.

• ? To compare the safety and efficacy of laparoscopic partial nephrectomy (LPN) in obese and non‐obese patients.
• ? We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), CINAHL, Clinicaltrials.gov, Google Scholar, reference lists of articles and abstracts from conference proceedings without language restriction for studies comparing LPN in obese and non‐obese patients.
• ? Four observational cohort studies were included for 256 obese patients compared with 403 non‐obese patients who underwent LPN.
• ? There was no difference in operative duration (mean difference [MD] 5.64, 95% confidence interval [CI]–3.80 to 15.09), warm ischaemic time (MD –1.04, 95% CI –2.68 to 0.59), estimated blood loss (MD 53.73, 95% CI 0.72–106.74) or hospital stay (MD –0.04, 95% CI –0.30 to 0.22).
• ? There was no difference in complications in total (odds ratio [OR] 1.02, 95% CI 0.70–1.49), intraoperative complications (OR 0.68, 95% CI 0.30–1.53), or postoperative complications (OR 1.15, 95% CI 0.75–1.77).
• ? The obese group had significantly more Clavien grade III complications (OR 3.95, 95% CI 1.36–11.42), despite the low absolute incidence, with 4.3% (11/256) in the obese group vs 1.5% (6/403) in the non‐obese group.
• ? Experienced laparoscopic surgeons can safely and efficiently perform PN for obese patients with comparable results to those of non‐obese patients.
• ? The likelihood of major (Clavien Classification ≥ III) complications is higher for the obese patient.