Estudo comparativo randomizado do efeito do laringoscópio óptico Airtraq vs. laringoscópio Macintosh sobre a pressão intraocular em cirurgia não oftálmica

Videolaryngoscopy versus direct laryngoscopy for adults undergoing tracheal intubation

BACKGROUND

Tracheal intubation is a common procedure performed to secure the airway in adults undergoing surgery or those who are critically ill. Intubation is sometimes associated with difficulties and complications that may result in patient harm. While it is traditionally achieved by performing direct laryngoscopy, the past three decades have seen the advent of rigid indirect videolaryngoscopes (VLs). A mounting body of evidence comparing the two approaches to tracheal intubation has been acquired over this period of time. This is an update of a Cochrane Review first published in 2016.

OBJECTIVES

To assess whether use of different designs of VLs in adults requiring tracheal intubation reduces the failure rate compared with direct laryngoscopy, and assess the benefits and risks of these devices in selected population groups, users and settings.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and Web of Science on 27 February 2021. We also searched clinical trials databases, conference proceedings and conducted forward and backward citation searches.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs with adults undergoing laryngoscopy performed with either a VL or a Macintosh direct laryngoscope (DL) in any clinical setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We collected data for the following outcomes: failed intubation, hypoxaemia, successful first attempt at tracheal intubation, oesophageal intubation, dental trauma, Cormack-Lehane grade, and time for tracheal intubation.

MAIN RESULTS

We included 222 studies (219 RCTs, three quasi-RCTs) with 26,149 participants undergoing tracheal intubation. Most studies recruited adults undergoing elective surgery requiring tracheal intubation. Twenty-one studies recruited participants with a known or predicted difficult airway, and an additional 25 studies simulated a difficult airway. Twenty-one studies were conducted outside the operating theatre environment; of these, six were in the prehospital setting, seven in the emergency department and eight in the intensive care unit.  We report here the findings of the three main comparisons according to videolaryngoscopy device type. We downgraded the certainty of the outcomes for imprecision, study limitations (e.g. high or unclear risks of bias), inconsistency when we noted substantial levels of statistical heterogeneity and publication bias. Macintosh-style videolaryngoscopy versus direct laryngoscopy (61 studies, 9883 participants) We found moderate-certainty evidence that a Macintosh-style VL probably reduces rates of failed intubation (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.26 to 0.65; 41 studies, 4615 participants) and hypoxaemia (RR 0.72, 95% CI 0.52 to 0.99; 16 studies, 2127 participants). These devices may also increase rates of success on the first intubation attempt (RR 1.05, 95% CI 1.02 to 1.09; 42 studies, 7311 participants; low-certainty evidence) and probably improve glottic view when assessed as Cormack-Lehane grade 3 and 4 (RR 0.38, 95% CI 0.29 to 0.48; 38 studies, 4368 participants; moderate-certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.51, 95% CI 0.22 to 1.21; 14 studies, 2404 participants) but this finding was supported by low-certainty evidence. We were unsure of the findings for dental trauma because the certainty of this evidence was very low (RR 0.68, 95% CI 0.16 to 2.89; 18 studies, 2297 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 96%). Hyperangulated videolaryngoscopy versus direct laryngoscopy (96 studies, 11,438 participants) We found moderate-certainty evidence that hyperangulated VLs probably reduce rates of failed intubation (RR 0.51, 95% CI 0.34 to 0.76; 63 studies, 7146 participants) and oesophageal intubation (RR 0.39, 95% CI 0.18 to 0.81; 14 studies, 1968 participants). In subgroup analysis, we noted that hyperangulated VLs were more likely to reduce failed intubation when used on known or predicted difficult airways (RR 0.29, 95% CI 0.17 to 0.48; P = 0.03 for subgroup differences; 15 studies, 1520 participants). We also found that these devices may increase rates of success on the first intubation attempt (RR 1.03, 95% CI 1.00 to 1.05; 66 studies, 8086 participants; low-certainty evidence) and the glottic view is probably also improved (RR 0.15, 95% CI 0.10 to 0.24; 54 studies, 6058 participants; data for Cormack-Lehane grade 3/4 views; moderate-certainty evidence). However, we found low-certainty evidence of little or no clear difference in rates of hypoxaemia (RR 0.49, 95% CI 0.22 to 1.11; 15 studies, 1691 participants), and the findings for dental trauma were unclear because the certainty of this evidence was very low (RR 0.51, 95% CI 0.16 to 1.59; 30 studies, 3497 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 99%). Channelled videolaryngoscopy versus direct laryngoscopy (73 studies, 7165 participants) We found moderate-certainty evidence that channelled VLs probably reduce rates of failed intubation (RR 0.43, 95% CI 0.30 to 0.61; 53 studies, 5367 participants) and hypoxaemia (RR 0.25, 95% CI 0.12 to 0.50; 15 studies, 1966 participants). They may also increase rates of success on the first intubation attempt (RR 1.10, 95% CI 1.05 to 1.15; 47 studies, 5210 participants; very low-certainty evidence) and probably improve glottic view (RR 0.14, 95% CI 0.09 to 0.21; 40 studies, 3955 participants; data for Cormack-Lehane grade 3/4 views; moderate-certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.54, 95% CI 0.17 to 1.75; 16 studies, 1756 participants) but this was supported by low-certainty evidence. We were unsure of the findings for dental trauma because the certainty of the evidence was very low (RR 0.52, 95% CI 0.13 to 2.12; 29 studies, 2375 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 98%).

AUTHORS' CONCLUSIONS

VLs of all designs likely reduce rates of failed intubation and result in higher rates of successful intubation on the first attempt with improved glottic views. Macintosh-style and channelled VLs likely reduce rates of hypoxaemic events, while hyperangulated VLs probably reduce rates of oesophageal intubation. We conclude that videolaryngoscopy likely provides a safer risk profile compared to direct laryngoscopy for all adults undergoing tracheal intubation.

Comparison of the effects of the McGRATH MAC, C-MAC, and Macintosh laryngoscopes on the intraocular pressures of non-ophthalmic patients: A prospective, randomised, clinical trial

INTRODUCTION

In this prospective, randomised study, we compared the effects of the Macintosh, McGRATH MAC, and C-MAC laryngoscopes on intraocular pressure (IOP) and haemodynamics of non-ophthalmic patients during endotracheal intubation.

METHODS

One hundred and twenty adult patients undergoing non-ophthalmic surgeries performed in the supine position under general anaesthesia requiring orotracheal intubation were included in this study. The patients were separated randomly and prospectively into 3 groups: Macintosh group (n = 40), McGRATH MAC group (n = 40), and C-MAC group (n = 40). Mean arterial pressure (MAP), heart rate (HR) and IOP of left and right eye were measured at specified times.

RESULTS

There were no significant differences with regard to patients characteristics. After intubation, the HR increased significantly in the Macintosh group when compared to the other groups (p = 0.001) and the MAP increased significantly in the Macintosh group when compared to the McGRATH MAC group (p = 0.001) and the C-MAC group (p < 0.001). The IOP values increased in the Macintosh group when compared to the McGRATH MAC group (p < 0.001) and the C-MAC group (p < 0.001) after intubation. Additionally, there was a significant difference between the McGRATH MAC group and C-MAC group in the IOP values of the eyes after intubation (p < 0.001). According to the evaluation within the groups, there were significant differences in all of the groups at all times when compared with the baseline values (p < 0.001).

CONCLUSIONS

In this study, we concluded that the C-MAC VL may be preferable when compared to the Macintosh and McGRATH MAC laryngoscopes for use in ophthalmic patients in whom a rise in the IOP is undesirable.

Endotracheal Intubation Criteria and Stress Response: Airtraq versus Macintosh Laryngoscopes - A Prospective Randomized Controlled Trial

Background:

Airtraq^® is a single-use video laryngoscope used to facilitate tracheal intubation in both expected and unexpected difficult airways.

Aims:

We hypothesized that Airtraq laryngoscope would facilitate better intubation criteria and lower stress response to laryngoscopy in comparison to the Macintosh laryngoscope.

Materials and Methods:

In this randomized, single-blinded, prospective study, 70 adult patients were randomly assigned to be intubated with either Airtraq (Group AT) or Macintosh (Group M) laryngoscope (35 patients in each). The primary outcomes involved intubation time, first-attempt success rate, time to best laryngoscopic view, and percentage of glottic opening (POGO) score. Other recorded parameters involved the hemodynamic and intraocular pressure (IOP) responses to laryngoscopy and intubation and complications during and after laryngoscopy and after extubation. Serum samples were collected before anesthesia induction and 2 min after intubation and analyzed for epinephrine, cortisol, and glucose.

Results:

Group AT had significantly higher POGO score and significantly shorter intubation time and time to best laryngoscopic view than Group M (P < 0.001). The first-attempt success rate was 97.1% in Group AT and 94.3% in Group M (P = 0.55). Postoperatively, laryngospasm and sore throat were encountered in 2.9% of Group M patients compared to 0% in Group AT (P = 1.00). The heart rate, mean arterial pressure, IOP, serum epinephrine, and cortisol were significantly increased in Group M than Group AT.

Conclusion:

In comparison to the Macintosh laryngoscope, Airtraq conferred significantly better intubation criteria and lesser stress response to laryngoscopy and intubation.

Airtraq® reduces the hemodynamic response to tracheal intubation using single-lumen tubes in adults compared with the Macintosh laryngoscope: A systematic review and meta-analysis of randomized control trials

STUDY OBJECTIVE

To investigate whether Airtraq® attenuate the hemodynamic responses to tracheal intubation using single-lumen tubes in adults as compared with the Macintosh laryngoscope.

DESIGN

Meta-analysis.

SETTING

Operating room.

MEASUREMENTS

The primary outcome of this meta-analysis was to determine whether laryngoscopy using the Airtraq® reduced hemodynamic responses-heart rate (HR) and mean blood pressure (MBP)-at 60 s (s) after tracheal intubation compared to laryngoscopy with the Macintosh laryngoscope. Pooled differences in these hemodynamic responses between the two devices were expressed as weighted mean difference with 95% confidence intervals. We then conducted trial sequential analysis (TSA). The secondary outcome was to investigate whether the Airtraq® reduce the hemodynamic response at 120 s, 180 s, and 300 s after tracheal intubation compared to the Macintosh laryngoscope. We also conducted sensitivity analysis of the hemodynamic responses to tracheal intubation with the laryngoscopes using a multivariate random effects model accounting for within-study correlation of the longitudinal data.

MAIN RESULTS

From electronic databases, we selected 11 randomized controlled trials for studies that enrolled subjects satisfying our inclusion criteria. Compared with the Macintosh laryngoscope, the Airtraq® significantly reduced both HR and MBP at 60 s after tracheal intubation. In secondary outcome, the Airtraq® significantly reduced both HR and MBP at all measurement points, excluding HR at 300 s after tracheal intubation. TSA showed that total sample size reached the required information size for both HR and MBP. The sensitivity analysis revealed that the Airtraq® reduced both HR and MBP at all measurement points, excluding HR at 300 s after tracheal intubation.

CONCLUSIONS

The Airtraq® attenuates the hemodynamic response at 60 s after tracheal intubation compared with the Macintosh laryngoscope. (GRADE: Low) These results were supported by the sensitivity analysis. TSA suggested that the total sample size was exceeded TSA monitoring boundary both HR and MBP.