Video Laryngoscopy versus Direct Laryngoscopy

Patient Presentation and Clinical Question

• Patient was a 54 yr old morbidly obese nursing home resident who was bedbound and hemiplegic due to a massive ischemic stroke secondary to Factor V Leiden 8 years prior.

• She presented to the ED with a cc of “fast heart rate”• Upon entering the room I noticed that she was extremely diaphoretic,

tachycardic to the 150s and her blood pressure was now 70s/30s.• The resident was immediately notified and we began goal directed therapy for

treatment of sepsis including placement of a central line. • During line placement the patient had two episodes of feculent emesis and it

was determined that she could no longer protect her airway.• Airway cart was obtained with various direct laryngoscope blades in addition to

the GlideScope. Direct laryngoscopy with endotracheal intubation was performed on first attempt with a 4.0 Macintosh blade.

• Is Video Laryngoscopy (VL) assisted intubation superior to Direct Laryngoscopy (DL) intubation? And if so, in what clinical settings?

Pre-hospital intubation

• Wayne, M. A., and M. McDonnell (2010) comparing DL with GlideScopre Ranger VL intubation in pre-hospital setting

• Retrospective chart review of 300 DL and 315 VL intubations of children and adults > 6yrs of age in EMS system with a 95% intubation success rate historically. – Study conclusion: There was no statistical difference in overall success rate btwn two groups;

VL was on average 21 seconds faster and resulted in average of 1.2 attempts less than DL to successful intubation; both statistically significant. This system also allowed for recording of intubation to be viewed at a later time to verify placement.

– Study flaws: Not RCT (selection bias), very experienced EMS provider population used in study with extensive intubation training (may not translate to other EMS systems), airway difficulty not assessed in study.

Table 1: Pt characteristics and study outcomes

Pre-hospital intubation

• Trimmel, H., et al (2011) comparing DL with Airtraq Laryngoscope (fiberoptic imaging of airway) in pre-hospital setting

• RCT study of 212 adults needing emergency intubation in pre-hospital setting by EMS staffed with physicians who were either board certified in emergency medicine or anesthesiology. – Study conclusion: Airtraq success rate was only

47% versus 99% for DL in pre-hospital setting by trained physicians. Previous non-RCT studies had shown Airtraq to be superior to DL.

– Importance of this study as relates to the clinical question: Well designed large RCT’s are necessary to validate new intubation technology, including those that provide direct imaging of the airway.

• Albrecht and Wiener-Kronish (2011) also point out that there is a paucity of RCT’s regarding DL vs VL and that the literature remains confusing on this topic in general.

RCT Flow Chart:

Emergency room intubation

• Platts-Mills, T. F., et al. (2009) comparing GlideScope VL to DL in ED setting• Prospective observational study in Level 1 trauma center ED with residents

intubating 280 adult patients with either GlideScope (22%) or direct laryngoscopy (78%) (physician’s choice). Primary outcome was first attempt success.– Study conclusion: 83% overall first attempt success rate, 81% first attempt success with VL and

84% with DL. No significant difference, “however, intubation using VL required significantly more time to complete.”

– Study flaws: Not RCT (selection bias), significantly lower number of VL to DL, upper level residents more likely to use VL (difference in intubation experience), airway difficulty not assessed in study, ED residents had all performed at least 50 DL intubations prior to study but had limited VL experience.

Table 2: Study outcome measures:

Take Home Points

1) Inadequate randomized control trials exist comparing DL and VL intubation.-There is no clear answer to my clinical question; if there was a clear winner, everyone would be

using is over the other.-Future trials would need to answer a number of questions regarding: Specific video laryngoscopy

systems, various levels of clinical experience, different training regimens, differing levels of airway difficulty and different clinical settings

2) The best method to intubate is likely the one that you are most experienced using.

-Although this is not the question asked by most studies, most of the data seems to show that providers had significantly more experience in DL which likely resulted in quicker intubation times and high success rates of both methods and clouded the results of theses studies.

3) Video Laryngoscopy is increasingly available in EDs and is likely to be increasingly used; opportunities should be sought out to become more proficient in its use.

-Raja et al showed that the availability of VL devices in EDs across Massachusetts has increased from less than 4% of ED rooms 5 years ago, to more than 40% today. With an even greater increase in large emergency departments. Half of EDs with associated Emergency Medicine residency programs had VL devices available.

References

Albrecht, M., and J. P. Wiener-Kronish. "Newer Technology is Not always Better." Critical Care Medicine 39.3 (2011): 591-2.

Platts-Mills, T. F., et al. "A Comparison of GlideScope Video Laryngoscopy Versus Direct Laryngoscopy Intubation in the Emergency Department." Academic Emergency Medicine 16.9 (2009): 866-71.

Raja, A. S., et al. "Adoption of Video Laryngoscopy in Massachusetts Emergency Departments." Journal of Emergency Medicine (2011)

Trimmel, H., et al. "Use of the Airtraq Laryngoscope for Emergency Intubation in the Prehospital Setting: A Randomized Control Trial." Critical Care Medicine 39.3 (2011): 489-93.

Wayne, M. A., and M. McDonnell. "Comparison of Traditional Versus Video Laryngoscopy in Out-of-Hospital Tracheal Intubation." Prehospital Emergency Care 14.2 (2010): 278-82.