This German study, published in Resuscitation in 2011, collected data regarding prehospital endotracheal intubations performed by physicians from a variety of specialties in both helicopter and ground EMS.
Of 276 patients analyzed, 86.9% were intubated on the first pass, 9.8% required 2 attempts, 1.1% required 3 attempts, and 1.4% could not be intubated.
The factors most commonly associated with difficult intubation were obesity, short neck, and limited space on scene. Limited space on scene more than doubled the probability of difficult intubation.
Full-text pdf for this article is available here (secure area limited to ADHB staff only – ADHB has online subscription access to this journal via the Philson Library at The University of Auckland School of Medicine)
To date, the most significant procedural capability the the addition of doctors to the ARHT Westpac Rescue Helicopter has provided has been RSI capability. Of the RSIs performed so far, a significant proportion have been for severe traumatic brain injury (TBI).
With the exception of surgical intervention (which is required in a minority of cases of severe TBI), most other essential elements of severe TBI management can be provided in the prehospital setting – airway protection, optimisation of oxygenation, prevention of hyper- or hypo-carbia, support of cerebral perfusion pressure, and ICP control.
This paper, published in the Journal of Neurosurgery in 2008, reviews the evidence around the various elements of the pre-hospital severe TBI care ‘package’.
- a period of hypoxia (PaO2<60mmHg) is associated with a 50% mortality rate and a 50% severe disability among survivors
- in previous studies hypoxia has been a common complication of prehospital intubation for severe TBI, with up to 57% of patients experiencing transient hypoxia lasting a mean of 2.3 minutes (note – these studies frequently involved neither an RSI as we know it nor personnel who were appropriately trained and qualified; more recent evidence points to a benefit for prehospital RSI for severe TBI provided it is done well by appropriate people)
- Tight control of CO2 after intubation has a significant effect on survival – in one large series patients with normal CO2 on arrival to ED had a 21% mortality, those with CO2 outside the normal range had a 34% mortality
- Manual ventilation is associated with hypocarbia
- A single episode of hypotension (systolic BP less than 90mmHG) doubles mortality
- Management of hypotension in the field improves outcome
- Transport by helicopter for patients with severe TBI improves odds of survival compared with ground transport (OR 1.6-2.25) – this may reflect the presence of more skilled personnel on the helicopter, careful attention to post-intubation ventilatory parameters, and transport to a trauma centre.