Hey all,
Doczilla asked I join the discussion. We both have been posting on the ACEP listserver about this topic, so this is what I posted:
A few points:
1. All agencies should be using waveform capnography as the "gold standard" to determine tube placement. With properly used waveform capnography there should be an almost zero percent missed esophageal intubation rate. This method of tube verification was advocated by a position paper from the National Association of EMS Physicians in 1999. ( http://www.naemsp.org/pdf/verificationtubeplacement.pdf ) It is a rapid and very reliable method of determining tube placement, much better than auscultation, tube fogging, colorometric CO2 detectors, etc. Why this has not become the standard of care in both the pre-hospital and ED settings is surprising, as if you ask our colleagues in anesthesia, no one is intubated without waveform capnography and it has been the standard of care in the OR for many years.
2. I believe that the current system by which we train paramedics to perform intubation is set up with the deck stacked against them. I worked as an EMT for many years before becoming a physician, and all my initial intubations were in either the OR or the ED. The first time I had to place a tube as the physician on an ambulance I was face down in a field with an anaphylactic patient deep in the woods on a very bright sunny day. It was an eye opener for me how much more difficult this was than placing a tube in the ED. Think about it -- as physicians we are accustomed to a well lit exam room, with an adjustable bed, staff to assist us, maybe anesthesia backup. Being in the middle of a field face down in the dirt without support staff is a very different experience. There is an interesting article from the Anesthesia literature in 2007 that shows that physicians that normally work in a hospital setting, when placed with a helicopter service, often had unrecognized esophageal intubations (no capnography was available) http://www.anesthesia-analgesia.org/cgi/co...tract/104/3/619
Flash to how we train our EMS providers: we place them in a sterile OR or ED, then once they get the "right number" of tubes send them out into the field to get a couple of "field tubes" and then that's it. Most never have the opportunity to come back to the ED/OR to practice, nor do we actually train them in the environment in which they work. Paramedic students should be getting many intubations using airway mannequins in real field conditions (dark rooms, bathrooms, dusty fields, etc.), and all practicing paramedics should have the opportunity (and be mandated) to continue to practice intubations both on airway mannequins, and back in the ED/OR to maintain their skills.
The combination of training the medics in our controlled ED environment and then sending them into a very different field environment, coupled with the lack of continuing education/practice, I feel is the source of many of the issues that have been raised within this discussion. Then, factor in the lack of waveform capnogrpahy in many places, and this just compounds the issue.
A recent article from the British Journal of Anesthesia shows intubation to be safe and beneficial for head injured patients with well trained providers: http://bja.oxfordjournals.org/cgi/content/full/96/1/67 Again training and education -- coupled with practice and good monitoring equipment -- is the key.
3. In the San Diego study that is often quoted (The effect of paramedic rapid sequence intubation on outcome in patients with severe traumatic brain injury. J Trauma. 2003 Mar;54(3):444-53.), the authors themselves noted that RSI improved paramedic success rates: "Paramedic RSI improves intubation success rates but is associated with an increase in mortality and decrease in 'good outcomes' when compared with hand-matched controls. These differences may reflect inherent inequities between the two groups, although they appeared similar on all parameters we measured. Alternatively, the increase in mortality may be related to inadvertent hyperventilation, transient hypoxic episodes, and prolonged scene times associated with the RSI procedure."
As the authors noted in their last sentence, further analysis of the data showed that hypertventilation and hypoxia was a large factor in the poor outcome of the patients, not the RSI procedure itself. (http://www.ncbi.nlm.nih.gov/pubmed/15284540 ) Well trained EMS providers with appropriate monitoring (continous ETCO2 and SPO2) and all available airway tools (including intubation/RSI when necessary) is the best way to minimize these complications. In fact, if you look at the literature from Europe (i.e. Acta Anaesthesiologica Scandinavica. 50(10):1250-4, 2006 Nov. "Effect of pre-hospital advanced life support with rapid sequence intubation on outcome of severe traumatic brain injury.") many trauma patients were dying from hypoxia from lack of airway control in BLS only systems, and the introduction of ALS showed a decrease in mortality for TBI patients.
A follow up study in the Journal of Trauma in 2007 showed that if TBI patients maintained normocapnea after intubation by medics, they did not have an increased mortality. ( http://www.ncbi.nlm.nih.gov/pubmed/17563643 )
In addition, a study from Journal of Trauma in 2005 showed that the use of a neuromuscular blocking agents by medics, when adjusted for confounding variables, actually improves outcomes for patients with TBI. ( http://www.ncbi.nlm.nih.gov/pubmed/15824647 )
Interestingly enough, there is an article in Archives of Surgery from San Diego pre-RSI that actually shows an improvement in patient outcome with pre-hospital intubation of head injuries ( http://archsurg.ama-assn.org/cgi/content/abstract/132/6/592 ). This further suggests that it is not the intubation that was the issue, but unrecognized hypoxia/hyperventilation/hypocapnea as noted.
A recent expert panel summarized this best:
"The Brain Trauma Foundation assembled a panel of experts to interpret the existing literature regarding paramedic RSI for severe TBI and offer guidance for EMS systems considering adding this skill to the paramedic scope of practice. The interpretation of this panel can be summarized as follows: (1) the existing literature regarding paramedic RSI is inconclusive, and apparent differences in outcome can be explained by use of different methodologies and variability in comparison groups; (2) the use of Glasgow Coma Scale score alone to identify TBI patients requiring RSI is limited, with additional research needed to refine our screening criteria; (3) suboptimal RSI technique as well as subsequent hyperventilation may account for some of the mortality increase reported with the procedure; (4) initial and ongoing training as well as experience with RSI appear to affect performance; and (5) the success of a paramedic RSI program is dependent on particular EMS and trauma system characteristics. (link: http://www.ncbi.nlm.nih.gov/pubmed/17169868 )
4. My opinion -- backed by a recent article in Journal of Trauma-Injury Infection & Critical Care [ "Prehospital Rapid Sequence Intubation for Head Trauma: Conditions for a Successful Program" 60(5):997-1001, 2006 May. ] -- is that RSI should be reserved for a small cadre of well trained paramedics that are available for the right cases and the sickest patients. It should not be every medic, every patient with a GCS < 8, or every CHF'er. The conclusion from their article is the same: "Prehospital RSI for trauma patients can be safely and effectively performed with low rates of complication and without significant delay in transport. This study suggests that resources for prehospital airway management should be focused on training, regular experience, and close monitoring of a limited group of providers, thereby maximizing their exposure and experience with this procedure."
Best regards,
EMSDoc 8)