|Year : 2017 | Volume
| Issue : 1 | Page : 1-6
Endotracheal intubation using direct laryngoscopy with Macintosh blade versus C-MAC videolaryngoscopy (Macintosh blade and D-blade)
Hossam Eldin Fouad Rida1, Nagwa Mahmoud Elkobbia1, Moustafa Abdel Aziz Moustafa2, Hend Abdel Nasser Aboshanab3
1 Professor of Anaesthesia, Faculty of Medicine, Alexandria, Egypt
2 Assistant Professor of Anaesthesia, Faculty of Medicine, Alexandria, Egypt
3 Specialist of Anaesthesia, Faculty of Medicine, Alexandria, Egypt
|Date of Submission||07-Oct-2015|
|Date of Acceptance||23-Nov-2015|
|Date of Web Publication||22-Mar-2017|
Hend Abdel Nasser Aboshanab
Sidi Beshr, 52 Madent Faisal, Alexandria
Source of Support: None, Conflict of Interest: None
Direct laryngoscopes have been developed to many optical fiberscopes to provide better view of the glottis without alignment of the oral, pharyngeal and tracheal axes. Recently, videolaryngoscopes have become increasingly important devices in difficult airway management.
The aim of the present study was to compare the efficacy of direct laryngoscopy using a conventional Macintosh blade with C-MAC videolaryngoscopy (with a Macintosh blade or D-blade), and to select the device of choice for the best first attempt for laryngoscopy and endotracheal intubation.
Patients and methods
A total of 90 adult patients were randomly categorized into three equal groups (30 patients each): group I, in which patients were subjected to general anaesthesia with endotracheal intubation using direct laryngoscopy with conventional Macintosh blade; group II, in which patients were subjected to general anaesthesia with endotracheal intubation using C-MAC videolaryngoscopy with conventional Macintosh blade; and group III, in which patients were subjected to general anaesthesia with endotracheal intubation using C-MAC videolaryngoscopy with the D-blade. Then, the assessment of the laryngoscopic view and the whole procedure of laryngoscopy and intubation was carried out.
This study validated the efficacy of C-MAC Macintosh blade and D-blade when compared with a direct laryngoscope. D-Blade has been found to be more effective in reducing haemodynamic responses to laryngoscopy and intubation. Its use improves the laryngoscopic view with a high success rate, makes the procedure of laryngoscopy and intubation easier from the first attempt and involves the least usage of assisting manoeuvres while achieving the shortest ETT insertion time without any complications.
Keywords: C-MAC, D-blade, direct laryngoscopy, endotracheal intubation, videolaryngoscopy
|How to cite this article:|
Fouad Rida HE, Elkobbia NM, Aziz Moustafa MA, Nasser Aboshanab HA. Endotracheal intubation using direct laryngoscopy with Macintosh blade versus C-MAC videolaryngoscopy (Macintosh blade and D-blade). Res Opin Anesth Intensive Care 2017;4:1-6
|How to cite this URL:|
Fouad Rida HE, Elkobbia NM, Aziz Moustafa MA, Nasser Aboshanab HA. Endotracheal intubation using direct laryngoscopy with Macintosh blade versus C-MAC videolaryngoscopy (Macintosh blade and D-blade). Res Opin Anesth Intensive Care [serial online] 2017 [cited 2020 May 31];4:1-6. Available from: http://www.roaic.eg.net/text.asp?2017/4/1/1/202697
| Introduction|| |
Direct laryngoscopy has been the standard technique for tracheal intubation for almost a century. However, the last two decades have seen the development of myriad alternative intubating devices.
While developing intubating devices, direct laryngoscope with its two main blades, Macintosh blade and the Miller blade, has been developed to many other optical fibrescopes to provide better view of the glottis without alignment of the oral, pharyngeal and tracheal axes .
Videolaryngoscopy is the most significant development in airway management in this century. In 2001, glidescope was the first generation of direct videolaryngoscopes; then, the development of other videolaryngoscopes followed, including C-MAC videolaryngoscope with its two blades, Macintosh blade and D-blade .
On comparing the C-MAC with the conventional Macintosh blade, the D-blade is half-moon-shaped, with an overall higher angulation. The highly angulated D-blade may be advantageous in the small number of cases of difficult airway that cannot be managed with a conventional C-MAC Macintosh blade. A conventional C-MAC Macintosh blade 3 has a blade angulation of 18°, whereas it is 40° in the D-blade, with an elliptically tapered blade shape rising to distal .
| Aim of the work|| |
The aim of the present study was to compare the efficacy of direct laryngoscopy using the conventional Macintosh blade with C-MAC videolaryngoscopy using the Macintosh or D-blade, and to select the device of choice for the best first attempt for laryngoscopy and endotracheal intubation.
| Patients and methods|| |
The present study was carried out in Alexandria University Hospitals on 90 adult patients belonging to ASA physical status I and II, and scheduled for elective surgery under general anaesthesia through endotracheal intubation.
Patients were randomly allocated into three equal groups (30 patients each) using the closed envelope method:
Group I: Patients were subjected to general anaesthesia with endotracheal intubation using direct laryngoscopy with a conventional Macintosh blade.
Group II: Patients were subjected to general anaesthesia with endotracheal intubation using C-MAC videolaryngoscopy with a conventional Macintosh blade.
Group III: Patients were subjected to general anaesthesia with endotracheal intubation using C-MAC videolaryngoscopy with a D-blade.
After obtaining approval from the local Ethical Committee and an informed consent from all patients, the patients were assessed preoperatively. All patients were premedicated with one tablet of alprazolam 0.25 mg 2 h before the operation.
On arrival in the operating room, patients were subjected to the standard monitoring through ECG, noninvasive arterial blood pressure, and pulse oximeter. They were all subjected to the same anaesthetic protocol. Induction was carried out with fentanyl 1 μg/kg and propofol 1.5–2 mg/kg. Orotracheal intubation was facilitated with rocuronium 0.6 mg/kg. Orotracheal intubation was carried out using the selected intubation device for each group with the endotracheal tube loaded over a stylet, and after ensuring full muscle relaxation, as assessed by using a nerve stimulator.
- Haemodynamic parameters, including heart rate (beats/min), mean arterial blood pressure and peripheral oxygen saturation (SpO2%), were measured. They were measured continuously and recorded before induction, before laryngoscopy, immediately after endotracheal intubation and then 3, 6 and 9 min after endotracheal intubation.
- End-tidal CO2 (ETCO2) was recorded immediately after endotracheal intubation, and then 3, 6 and 9 min after endotracheal intubation.
- Laryngoscopic view was assessed using the modified Cormack–Lehane scoring system .
- Extent of the laryngoscopic view . Description of the anatomical boundaries of the glottis seen via laryngoscopy.
- Assessment of laryngoscopy and intubation procedure included the following:
- Number of trials to successful intubation.
- Following manoeuvres were used during laryngoscopy:
- BURP (Backward, Upward, Rightward, Posterior) external laryngeal maneuver.Changing the blade size in the second trial of laryngoscopy.
- Endotracheal tube insertion time was calculated from introducing the laryngoscope blade through the patient’s mouth till successful intubation was confirmed by the normal capnogram waveform.
- Success/failure rate.
- Ease of laryngoscopy and endotracheal tube insertion .
- Complications, such as possible traumatization, were assessed.
Data were tested for normal distribution, and analysed by using the independent t-test for three independent groups, the paired t-test for paired samples and the χ2-test and Fisher’s exact test for qualitative data.
Results were presented in the form of range, percentage (%), arithmetic mean (χ2) and SD. A P value of less than 0.05 was considered statistically significant.
| Results|| |
Regarding haemodynamic changes, comparison between the three studied groups showed that heart rate was significantly lower in group II and III relative to group I immediately after intubation with a P value of 0.029 and 0.002, respectively, and was significantly higher in group II and III relative to group I 9 min after intubation with a P value of 0.001 and 0.002 ([Figure 1]).
Mean arterial blood pressure was significantly lower in group II and III compared with group I, immediately after intubation with a P value of less than 0.001 and 0.007, respectively, 3 min after intubation with a P value of less than 0.001 and 0.013, respectively, 6 min after intubation with a P value of less than 0.001 and 0.001, respectively, and then 9 min after intubation with a P value of less than 0.001 and 0.001, respectively ([Figure 2]).
|Figure 2 Comparison between the studied groups according to mean arterial blood pressure (MBP).|
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ETCO2 was significantly lower in group II and III compared with group I, immediately after intubation with a P value of less than 0.001 and 0.001, respectively ([Figure 3]).
As regards the laryngoscopic view, described by the modified Cormack–Lehane (C–L) scoring system , in group I (DL), 50% of the patients were found to be grade I C–L, 36.7% were grade IIa C–L and 13.3% were grade IIb C–L.
In group II (C-MAC), 80% of the patients were found to be grade I C–L, 16.7% were grade IIa C–L and 3.3% were grade IIb C–L, whereas in group III (D-blade) 93.3% were found to be grade I C–L and 6.7% were grade IIa C–L. There was a statistically significant difference between the three groups as regards their Cormack–Lehane score ([Figure 4]).
|Figure 4 Comparison between the studied groups according to modified Cormack–Lehane scoring.|
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Three patients in group I (DL) had successful intubation from the second trial, in which we had to change the laryngoscopic blade size from 4 to 5. In group II (C-MAC), only one patient had successful intubation from the second trial, in which we had to change the blade size from 3 to 4. In group III (D-blade), all patients were successfully intubated from the first trial ([Figure 5] and [Figure 6]).
|Figure 5 Comparison between the studied groups according to the number of trials to successful intubation.|
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|Figure 6 Comparison between the studied groups according to the change in the blade size in the second trial of laryngoscopy.|
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BURP manoeuvre was used for 56.7% of the patients in group I (C-MAC), for 20% of patients in group II and for one patient in group III (D-blade) ([Figure 7]).
|Figure 7 Comparison between the studied groups according to BURP manoeuvre during laryngoscopy.|
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There was no statistical significant difference among the three groups regarding the success rate of intubation.
The total endotracheal tube insertion time was found to be significantly longer in group I (DL) with a mean of 41.53±27.63 s, whereas in group II (C-MAC), it was 22.07±15.26 s and in group III (D-blade) it was 17.43±3.69 s ([Figure 8]).
|Figure 8 Comparison between the studied groups according to endotracheal tube insertion time in seconds.|
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| Discussion|| |
The present study demonstrated that the C-MAC D-blade maintains haemodynamic stability during endotracheal intubation.
This is in agreement with a study by Ralph et al. , who conducted his study on cardiac patients of ASA physical status III and IV.
In addition, a study by Nishikawa et al.  found that stress response of intubation is reduced with ‘glidescope’ videolaryngoscope when compared with the conventional laryngoscope.
In contrast, in their study, Tsai and Chen  found that there was a significant increase in the haemodynamic parameters in the glidescope group (GS) and the airway scope group (AWS) compared with the direct laryngoscopy group (DL), which was attributed to the long intubation time.
The glottis view was found to be best achieved with the highly angulated D-blade through looking around the curve of the tongue and seeing the whole relations anterior, posterior, right and left lateral in 100% of the patients.
A study by Cavus et al.  demonstrated significant difference in the laryngoscopic view extents, which had been achieved by using D-blade videolaryngoscope with an improvement in the Cormack–Lehane score during the first clinical evaluation of C-MAC D-blade.
A study by Kaplan et al.  also demonstrated significant improvement in the Cormack–Lehane score while using videolaryngoscope to obtain a direct naked eye view with external laryngeal manoeuvres and a video monitor view within the same attempt.
In addition, these findings were in line with those reported in the studies by Serocki et al. , Sakles et al.  and Noppens et al. , who compared C-MAC D-blade and conventional direct laryngoscope in patients with suspected difficult airways, in emergency department and in the ICU, respectively.
However, in their study, Carsten et al. , on the basis of an assessment of the glottic view during routine induction of anaesthesia, reported that there was no significant difference on comparing direct laryngoscope with C-MAC videolaryngoscope.
On assessment of the whole procedure of laryngoscopy and intubation, it was found that C-MAC D-blade in group III had the best outcome as regards the number of trials to successful intubation with 100% of patients successfully intubated from the first trial.
Success rate of intubation was not statistically significant among patients of the three groups.
On the other hand, a study by Serocki et al.  showed higher success rate of intubation on comparing D-blade, glidescope and direct laryngoscope, which was 100% for both D-blade and GS, while four patients could not be intubated using a conventional direct laryngoscopy.
In addition, a study by Sakles et al.  showed a success rate of 97.3% for C-MAC videolaryngoscope compared with 84.4% for conventional direct laryngoscope.
A study by Jungbauer et al.  also showed a high success rate of 92% during direct laryngoscopy compared with 99% during videolaryngoscopy in 200 patients with expected difficult intubation. The study also showed significant decrease in the numbers of optimizing manoeuvres to the process of laryngoscopy and intubation.
In contrast to the findings of the present study, Cavus et al.  in their study demonstrated the difficult procedure of laryngoscopy and intubation while using the D-blade, where three or four attempts were needed until successful intubation was achieved for five out of 20 patients when the blade was used as a rescue device after encountering failure during direct laryngoscopy.
The present study showed that the endotracheal tube’s total insertion time was least among patients in group III (D-blade), which may be attributed to a better view of the glottis and less optimizing manoeuvres needed.
Similar to the present study, in their respective studies, Sulser et al.  and Jungbauer et al.  reported a significantly shorter insertion time with C-MAC videolaryngoscope when compared with the conventional laryngoscope in the emergency department and during routine induction of anaesthesia, respectively.
In contrast, a study by Tsai and Chen  reported a significantly longer insertion time, which was associated with increased cardiovascular responses to laryngoscopy and intubation; insertion time was highest in the AWS group, followed by the GS and DL groups.
In their respective studies, Serocki et al.  and Carsten et al.  showed that there was no significant difference between the time needed to achieve laryngeal view and successful intubation between the videolaryngoscope group and the direct laryngoscope group.
D-Blade has been found to be more effective in reducing haemodynamic responses to laryngoscopy and intubation. Its usage improves the laryngoscopic view with a high success rate, makes the procedure of laryngoscopy and intubation easier from the first attempt, and involves the least usage of assisting manoeuvres while achieving the shortest ETT insertion time.
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Conflicts of interest
There are no conflicts of interest.
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