Post is coauthored by Ashley Keiler-Green MD, EM/Critical Care Attending, University of New Mexico School of Medicine

This post is part of the COMM CHECK series on communication during resuscitation.

Silence is a source of great strength -Lao Tzu

The Sterile Cockpit

Communication is a key aspect of safe and efficient task execution in all high-risk environments. However, too much communication, communicating at the wrong time, or sharing inappropriate information can be dangerous. Nowhere has this become more evident than the aerospace community.

In 1974, Eastern Air Lines Flight 212 was on approach to land in Charlotte, NC. There was significant fog at the airport and the crew engaged in a challenging instrument approach. Despite the difficulty and danger involved, the “experienced” crew were recorded talking about politics, the economy, and personal hobbies. During the course of their conversation, the pilots were unaware of their low altitude and crashed into the terrain approximately 3.3 miles short of the runway. 72 people lost their lives.1

Following this sentinel event, as well as several other unfortunate accidents2, the Federal Aviation Administration (FAA) enacted Federal Aviation Regulation (FAR) 121.542 and FAR 135.100 “Flight Crew Member Duties”3which established the policy colloquially known as the “Sterile Cockpit Rule”. The rule essentially banned non-essential communication during the “critical” phases of flight. The regulation reads:

a) No certificate holder shall require, nor may any flight crew member perform any duties during a critical phase of flight except those duties required for the safe operation of the aircraft. Duties such as company required calls made for non-safety related purposes as ordering galley supplies and confirming passenger connections, announcements made to passengers promoting the air carrier or pointing out sights of interest and filling out company payroll and related records are not required for the safe operation of the aircraft.

(b) No flight crew member may engage in, nor may any pilot in command permit, any activity during a critical phase of flight which could distract any flight crew member from the performance of his or her duties or which could interfere in any way with the proper conduct of those duties. Activities such as eating meals, engaging in non-essential conversations within the cockpit and non-essential communications between the cabin and cockpit crews, and reading publications not related to the proper conduct of the flight are not required for the safe operation of the aircraft.

(c) For the purposes of this section, critical phase of flight involves all ground operations involving taxi, takeoff and landing, and all other flight operations conducted below 10,000 feet, except cruise flight.

Since establishing the Sterile Cockpit Rule, on-going research has revealed some interesting findings. Violation of the Sterile cockpit has continued to contribute to untoward events.4,5,6,7 A review of NASA’s Aviation Safety Reporting System found that unnecessary communication during key aspects of flight led to major issues. 63 major incidents were analyzed where violation of Sterile Cockpit was determined to be a major contributing factor to the accident. The violations consisted of extraneous conversations, distractions by flight attendants, non-pertinent radio calls (e.g. checking on connecting flights), non-critical public addresses (e.g. advertising for the airline) and even sight-seeing communications! In these events, the violations led to 30 altitude deviations, 9 course deviations, and 1 near mid-air collision.8

Distraction and Disruption

These results shouldn’t be surprising in the context of other Human Factors research regarding communication. In general, the timing and content of verbal communication in high-risk situations is critical.9,10,11 The same seems to hold true in the clinical environment.12,13,14

The Sterile Cockpit is designed, as mentioned earlier, to eliminate non-critical communication and focus on critical aspects of communication. This is important because distractions and loss of attention tend to lead to error and/or failure to successfully complete objectives.15,16,17,18,19 Difficulty with attention control and distraction are even more pronounced in stressful situations.20,21,22

In the clinical setting, Gaba et al have explored these concepts extensively in their anesthesia and Crisis Resource Management research.23,24 Their findings were shockingly similar to other high-stress and high-risk industries. While no outcomes were measured regarding performance or patient outcomes, Healy et al found that distractions during surgical procedures are quite common.25 Likewise in the emergency department, Berg et al catalogued and quantified interruptions and found that the average provider experienced more than 5 interruptions per hour to tasks requiring concentration and mental effort.26 This might be significant considering that, on average, providers make more than 5 medical errors (ordering wrong studies, prescribing wrong medications, documenting incorrectly, etc.) for every 100 hrs worked.27 In fact, some literature suggests that there is a strong, direct relationship between interruption and errors. 28,29,30

Silence is Golden

Limiting communication to only task-essential information seems to have improved safety in aviation5,7,31and has become a ubiquitous in Crisis Resource Management communication training32,33,34(required education in the commercial aviation industry).

There is a growing body of evidence that implementing a similar strategy in certain areas of medicine might also be effective.35 For example, the nursing literature has demonstrated improved safety during medication procurement and administration when the sterile cockpit concept was applied.36,37 While, to date, there is no data that demonstrates improved outcomes when the concept is applied in scheduled anesthesia cases, the specialty has recognized that noise and distractions can be dangerous during induction and embraces the idea.38 In fact, sterile cockpit is taught as part of Anesthesia Crisis Resource Management training.39,40

Wadhera et al attempted to apply the sterile cockpit concept during cardiac surgery. They performed a before and after study looking at the effects of structured communication protocol (including the sterile cockpit). In their investigation, they looked at critical stages of cardiac surgical procedures (e.g. initiating bypass) and used a validated communication tool to see the effect of the implementation of their protocol. They noticed a significant decrease in communications breakdowns and concluded the protocol helped them improve safety.41

Application to Resuscitation

As with any concepts from an outside industry, the concept of sterile cockpit has to be carefully and thoughtfully applied to resuscitation. The chaotic environments in the ED and ICU, where many different tasks are happening in parallel and not on a clearly delineated schedule, is different from the departure and take off of a commercial airliner. Wadhera et al actually commented on this in their study, mentioned above. Instead of applying the sterile cockpit for a particular length of time or until a discrete endpoint (e.g. surgery start until the patient was on bypass), they wisely applied it only at critical action sequences (e.g. just the transition on or off bypass). This seems like a very reasonable adaptation of the concept.

In resuscitation it may be more challenging, but certainly possible to apply the concept. For example, while resuscitating a polytrauma patient it might be difficult to have the entire trauma bay silent for each critical procedure (IV placement, intubation, chest tube placement…even central access or arterial line placement if indicated). Often, there is a lot that needs to happen in rapid succession and even multiple critical procedures that need to be performed simultaneously. Although keeping extraneous conversation to a minimum may be warranted, it would be impractical to force silence and/or force procedures to occur in series. That said, for certain critical procedures across the spectrum of resuscitation this may be more reasonable. Take, for instance, a patient that needs emergent intubation due to acute hypoxic respiratory failure or inability to protect their airway. As this might be the clinical bottleneck, the primary or key procedure upon which all else is predicated, enacting sterile cockpit may be prudent.

The evidence presented above regarding distraction and error also applies to non-emergent situations. There are plenty of tasks and procedures performed in the ED and ICU that are urgent or routine: from chest tube placement, to central line insertion, to procedural sedation. Having a quiet room and minimizing distraction might also be beneficial in these circumstances.

In terms of when to initiate and terminate the sterile cockpit, it may be best to isolate it to the periods of highest risk or when provider concentration/cognitive load is highest. Referring to the example of intubation, one might initiate the sterile cockpit at the end of the checklist or after the medications have been administered. The sterile cockpit might end once the tube placement is confirmed and everything is secured. The precise verbiage may be less important: “…sterile cockpit, please” or “…all quiet for the procedure, please” would be reasonable.

Let me know what you think. Do you use the sterile cockpit rule in the OR, ED, or ICU? How do you apply the concept? How do you decide when to use it or what procedures you deem to be “critical” aspects of resuscitation?

References

US National Transportation Safety Board (NTSB). Eastern Air Lines, Douglas DC 9-31, N8984E. Charlotte, NC. September 11, 1974. Aircraft Accident Report, NTSB/AAR-89/04. National Transportation Safety Board. September 1989. US National Transportation Safety Board (NTSB). Pacific Southwest Airlines B-727, N533PS and Gibbs Flight Center Cessna 172, N7711G. San Diego, CA. September 15, 1978.Aircraft Accident Report, NTSB/AAR-79/5. April 1979. S. FAR 121.542/135.100, “Flight Crewmember Duties”.Federal Aviation Administration. 19 January 1981. US National Transportation Safety Board (NTSB).Loss of control on approach Colgan Air, Inc. operating as Continental Connection Flight 3407 Bombardier DHC-8-400, N200WQ Clarence Center. Aircraft Accident Report, NTSB/AAR-10/01. February 2009. Chute RD, Wiener EL, Dunbar MG, Hoang VR. Cockpit/Cabin Crew Performance: Recent Research. Proceedings of the 48thInternational Air Safety Seminar. Seattle, WA. 7 November 1995. US National Transportation Safety Board (NTSB). Delta Air Lines, Boeing 727-232, N473DA. Dallas-Fort Worth International Airport, Texas. August 31, 1988.Aircraft Accident Report, NTSB/AAR-89/04. September 1989. Sumwalt RL. Accident and Incident Reports Show Importance of ‘Sterile Cockpit’ Compliance. Flight Safety Digest. 1994; 7: 1-10. Sumwalt RL. The Sterile Cockpit. Aviation Safety Reporting System Directline. https://asrs.arc.nasa.gov/publications/directline/dl4_sterile.htm. Accessed 4 November 2018. Goguen J, Linde C, Murphy M.Crew Communication as a Factor in Aviation Accidents.NASA Technical Report 88254. Moffett Field, CA: NASA-Ames Research Center. 1986. Predmore SC. Microcoding of Communications in Accident Investigation: Crew Coordination in United 811 and United 232. Proceedings of the Sixth International Symposium on Aviation Psychology. Columbus, OH: The Ohio State University; 1991. Ruffell Smith HP. 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