Parallel Parking and Aryepiglottic Folds
by Bobby Redwood, MD, MPH
I am really good at parallel parking; I pride myself on it. I went to medical school in Chicago and used to wedge my Volkswagen Jetta into parking spaces with less than a three inch gap on either bumper (we won't talk about the "love taps"). I recently bought a new car and, for the first time ever, I am now parallel parking with the assistance of a back-up camera. The precision is amazing. If needed, I can shrink that three inch gap down to one or two with no bumper to bumper contact whatsoever. The speed with which I parallel park has increased as well. A one-minute maneuver can reliably be done in 45 seconds with the assistance of the handy back-up camera. Still, some things seem a bit off. I've hit the curb a few times, which never happened before and I notice myself paying less attention to the traffic around me compared to my pre-back-up camera days. Basically, my level of situational awareness has decreased since I've been supplied with the luxury of direct rear bumper visualization. In inclement weather, when my back-up camera is fogged up or otherwise obscured, it feels clunky and awkward to go back to the old rubbernecking method. My once-lauded parallel parking skills are slipping.
As an emergency physician, its hard to look at the little rectangular screen of the back-up camera and not be reminded of another innovation in my life: video laryngoscopy. Video laryngoscopy (VL) is certainly on the rise in U.S. emergency departments. Recent surveys report that about 30% of emergent intubations are performed with VL compared to only 1% a decade ago. In residency, I almost exclusively intubated using direct laryngoscopy (DL), using VL as a rescue method for difficult intubations. In my current practice, I find that I'm clinging to DL in order to keep my skills up, but increasingly reaching for VL first in a variety of scenarios including C-collars, severe kyphosis, trismus, and angioedema. In all honesty, I am inching my way towards a VL-dominated practice, but I want to be sure I don't lose my situational awareness during "inclement weather" (read: blood and vomit). As VL becomes more ubiquitous, I imagine many EPs across the state are experiencing a similar tug-of-war in their practice style, which of course begs the question: which is better?
Like any reasonable emergency physician seeking an answer to a clinical question, I went to the literature...unfortunately, there's just not that much out there. An April 2016 non-blinded, non-randomized controlled trial at Hennepin County Medical Center ED found similar first past success rates between DL (86%) and VL (92%), even with difficult airways [difference was not statistically significant]. Similarly, a March 2017 meta-analysis on the same topic from the critical care literature included four randomized controlled trials and concluded that VL did not improve the rate of successful intubation on first attempt compared to DL. The EMRAP podcast made a statement that VL should be considered standard of care and the comment section exploded with DL supporters expressing a spectrum of emotions ranging from calm composed dissent to shock and righteous indignation. By any measure, the EM jury is still out on DL vs. VL.
In a 2010 report, the Department of Transportation's National Highway Traffic Safety Administration reported that each year 210 people die and 15,000 are injured in light-vehicle backup incidents, with about 31% of the deaths among kids under age 5 and 26% adults over 70. They estimated that 58 to 69 lives will be saved each year (not including injuries prevented) if the entire on-road vehicle fleet had "rear-view visibility systems." Acting on this observational, retrospective evidence, the NHTSA, will soon require that all automobiles sold in the United States (beginning in May 2018) be equipped with back-up cameras.
Government officials are not typically trained in the scientific method. Unlike the house of medicine, the NHTSA doesn't need a randomized controlled trial to make a judgement call. They feel pretty confident that back-up cameras make driving safer and also save lives. While the jury may still out on DL vs. VL for emergent intubations, that doesn't mean we at WACEP can't opine a bit. What has your experience been with VL? Has it become standard of care in your ED? Does a generation gap exist between DL and VL as it does with other forms of technology? Are there pros or cons that we have not discussed here?
Let's get some (admittedly non-scientific) Wisconsin specific data on the subject. Please fill out the following survey and use the last free text field to answer any of the questions posed above. If we get greater than 25 responses, we'll report the data on the WACEP website and hopefully inspire an ongoing conversation about how Wisconsin EPs feel about DL and VL (...not to mention back-up cameras).
Bobby Redwood MD, MPH
Driver, BE et al. Direct versus video laryngoscopy using the C-MAC for tracheal intubation in the emergency department, a randomized controlled trial. Acad Emerg Med. 2016 Apr;23(4):433-9.
Zhao, Bing-Cheng, Tong-Yi Huang, and Ke-Xuan Liu. "Video laryngoscopy for ICU intubation: a meta-analysis of randomised trials." Intensive Care Medicine (2017): 1-2.