CLASSIFICATION AND ASSESSMENT OF THE DIFFICULT PEDIATRIC AIRWAY

Comparative evaluation of CMAC and Truview picture capture device for endotracheal intubation in neonates and infants undergoing elective surgeries: A prospective randomized control trial

BACKGROUND

Videolaryngoscopy has an established role in difficult airway management in adults. However, there is limited literature to support their efficacy in children. The Truview Picture Capture Device has shown promising results for endotracheal intubation in infants in the past. The CMAC videolaryngoscope has launched its novel infant Miller blade, but its performance has not been assessed clinically for routine intubation in infants and neonates. We hypothesized that the CMAC videolaryngoscope would reduce the total time to intubation as compared to the Truview Picture Capture Device in neonates and infants.

METHODS

After parental informed consent, 80 prospective infants posted for surgical procedures under general anesthesia were randomized to undergo intubation with either of the two. The two videolaryngoscopes were also compared in terms of time required for glottis view and intubation (primary outcome), modified Cormack and Lehane grade, first attempt and overall success rate, ease of intubation, number of attempts, and any complications.

RESULTS

The CMAC significantly reduced the time required for glottic view [8 s (5.25-9) vs 9 s (6.5-12); P = 0.02] and intubation [22 s (18-26) vs 26 s (21.5-32); P = 0.003]. The median difference (95% CI) for time to tracheal intubation and time to glottic view was 4 s (1-7) and 1 (0-4). It also improved the ease of intubation, the Cormack-Lehane grades, and first attempt success rate. Intubation with the CMAC was possible in 100% cases, whereas only 92.5% of patients could be intubated with the Truview. The failed intubations with the Truview could be successfully intubated with the CMAC.

CONCLUSION

The CMAC Miller blade reduced the total time taken for tracheal intubation and intubation difficulty as compared to the Truview Picture Capture Device and may be a better tool for intubation in infants.

Comparison of the TruView infant EVO2 PCD™ and C-MAC video laryngoscopes with direct Macintosh laryngoscopy for routine tracheal intubation in infants with normal airways

OBJECTIVE

Videolaryngoscopy has mainly been developed to facilitate difficult airway intubation. However, there is a lack of studies demonstrating this method's efficacy in pediatric patients. The aim of the present study was to compare the TruView infant EVO2 and the C-MAC videolaryngoscope with conventional direct Macintosh laryngoscopy in children with a bodyweight ≤10 kg in terms of intubation conditions and the time to intubation.

METHODS

In total, 65 children with a bodyweight ≤10 kg (0-22 months) who had undergone elective surgery requiring endotracheal intubation were retrospectively analyzed. Our database was screened for intubations with the TruView infant EVO2, the C-MAC videolaryngoscope, and conventional direct Macintosh laryngoscopy. The intubation conditions, the time to intubation, and the oxygen saturation before and after intubation were monitored, and demographic data were recorded. Only children with a bodyweight ≤10 kg were included in the analysis.

RESULTS

A total of 23 children were intubated using the C-MAC videolaryngoscope, and 22 children were intubated using the TruView EVO2. Additionally, 20 children were intubated using a standard Macintosh blade. The time required for tracheal intubation was significantly longer using the TruView EVO2 (52 sec vs. 28 sec for C-MAC vs. 26 sec for direct LG). However, no significant difference in oxygen saturation was found after intubation.

CONCLUSION

All devices allowed excellent visualization of the vocal cords, but the time to intubation was prolonged when the TruView EVO2 was used. The absence of a decline in oxygen saturation may be due to apneic oxygenation via the TruView scope and may provide a margin of safety. In sum, the use of the TruView by a well-trained anesthetist may be an alternative for difficult airway management in pediatric patients.

Incidence of difficult bag-mask ventilation in children: a prospective observational study

BACKGROUND

Difficult airway (DA), including difficult bag-mask ventilation (DBMV), and difficult intubation (DI) is an important challenge for the pediatric anesthesiologist. While expected DBMV can be successfully managed with appropriate equipment and personnel, unexpected DBMV relies on the resources available and the experience of the anesthesiologist at the time of the emergency. The incidence and risk factors of unexpected DA in otherwise healthy children, including DBMV among pediatric patients are not known. The aim of this study was to expand the scientific knowledge of unexpected DBMV among pediatric patients.

METHODS

Patients between the ages of 0 and 8 years, undergoing elective surgery requiring bag-mask ventilation BMV and intubation at the Montreal Children's Hospital were recruited in this prospective observational study. Data on the incidence of DBMV and risk factors were collected over a 3-year period.

RESULTS

In a sample of 484 children, the incidence of unexpected difficult BMV was 6.6% (95% CI [4.6, 9.2]). The incidence of expected DA among the screened patients (N = 4865) was 0.5% (95% CI [0.3, 0.7]). In a logistic regression analysis, age (OR 0.98; 95%CI [0.97, 0.99]), undergoing otolaryngology (ENT) surgery (OR 2.92; 95% CI [1.08, 7.95]) and use of neuromuscular blocking agents (OR 3.49; 95%CI [1.50-8.11]) were independently associated with DBMV. The incidence of DI was 1.2%. No association between DBMV and DI was found (Fisher's exact test, P = 1.0).

CONCLUSIONS

This is the first published report of the incidence of unexpected DBMV among healthy pediatric patients.

A comparison of the GlideScope video laryngoscope and standard direct laryngoscopy in children with immobilized cervical spine

OBJECTIVES

Airway management in children with cervical spine may make direct laryngoscopy difficult. Video laryngoscopy is an alternative to direct laryngoscopy. The GlideScope video laryngoscope, successfully used in expected and unexpected difficult pediatric airway situations, has not been studied so far in children with cervical spine immobilization.

METHODS

A total of 23 children underwent laryngoscopy with manual cervical spine immobilization using the GlideScope and a direct laryngoscope (Miller 1 or Macintosh 2 blade). Percentage of glottis opening score, Cormack-Lehane score, and time to best view were recorded.

RESULTS

Percentage of glottis opening score using the GlideScope was 50% (1%-87%) and 90% (60%-100%) using direct laryngoscopy (P < 0.001). Cormack-Lehane score using the GlideScope was 1 (1-2.7) and 1 (1-1) in direct laryngoscopy (P < 0.001). Time to best view with the GlideScope was 21 seconds (12.2-28 seconds) and 7 seconds (6-8.7 seconds) in direct laryngoscopy (P < 0.05). Data are presented as median and interquartile range and analyzed using paired t test.

CONCLUSIONS

In simulated difficult pediatric airway, using the GlideScope resulted in a significantly declined view to the glottic entrance. This result is in contrast to studies in children with difficult airway anatomy due to an anterior larynx, where the GlideScope resulted in improved views.

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.

A comparison of the STORZ video laryngoscope and standard direct laryngoscopy for intubation in the Pediatric airway--a randomized clinical trial

INTRODUCTION

Direct laryngoscopy can be challenging in infants and neonates. Even with an optimal line of sight to the glottic opening, the viewing angle has been measured at 15 degrees . The STORZ DCI video laryngoscope (Karl Storz, Tuttlingen, Germany) incorporates a fiberoptic camera in the light source of a standard laryngoscope of variable sizes. The image is displayed on a screen with a viewing angle of 80 degrees . We studied the effectiveness of the STORZ DCI as an airway tool compared to standard direct laryngoscopy in children with normal airway.

METHODS

In this prospective, randomized study, 56 children (ages 4 years or younger) undergoing elective surgery with the need for endotracheal intubation were divided into two groups: children who underwent standard direct laryngoscopy using a Miller 1 or Macintosh 2 blade (DL) and children who underwent video laryngoscopy using the STORZ DCI video laryngoscope with a Miller 1 blade (VL). Time to best view (TTBV), time to intubate (TTI), Cormack-Lehane (CL), and percentage of glottis opening seen (POGO) score were recorded.

RESULTS

TTBV in DL was 5.5 (4-8) s and 7 (4.2-9) s in VL. TTI in DL was 21 (17-29) s and in VL 27 (22-37) s (P = 0.006). The view as assessed by POGO score was 97.5% (60-100%) in DL and 100% (100-100%) in the VL (P = 0.003). Data are presented as median and interquartile range and analyzed using t-test.

DISCUSSION

This study demonstrates that the STORZ DCI video laryngoscope provides an improved view to the glottis in children with normal airway anatomy, but requires a longer time for intubation.