Researchers from the London Helicopter Emergency Medical Service describe the success of pre-hospital laryngoscopy according to the grade and specialty of the HEMS physician…
There is conflicting evidence concerning the role and safety of prehospital intubation, and which providers should deliver it. Success rates for physician-performed rapid sequence induction are reported to be 97-100%, with limited evidence of improved survival in some patient groups. However, there is also evidence that prehospital intubation and ventilation can do harm. Prospective data were recorded on the success of intubation, the quality of the laryngeal view obtained and the number of attempts at intubation. These data were then analysed by the grade of intubating doctor and whether the intubating doctor had a background in anaesthesia or emergency medicine. All groups had a similar success rate after two attempts at intubation. Doctors with a background in anaesthesia and consultant emergency physicians had a significantly better first-pass intubation rate than emergency medicine trainees. The quality of laryngeal view was significantly better in doctors with an anaesthetics background.
Success in physician prehospital rapid sequence intubation: what is the effect of base speciality and length of anaesthetic training? Emerg Med J. 2011 Mar;28(3):225-9
Pre-hospital non-invasive ventilation for patients with acute dyspnoea features in two journals this month. Researchers at the Ambulance Service New South Wales published an evidence-based review of pre-hospital NIV for acute cardiogenic pulmonary oedema, concluding that there are probable benefits.
Background Non-invasive ventilation (NIV) is increasingly being implemented by many ambulance jurisdictions as a standard of care in the out-of-hospital management of acute cardiogenic pulmonary oedema (ACPO). This implementation appears to be based on the body of evidence from the emergency department (ED) setting, with the assumption that earlier administration by paramedics would give benefits with regard to inhospital mortality and the rate of endotracheal intubation beyond those seen when initiated in the ED. This paper sought to identify and review the current level of evidence supporting NIV in the prehospital setting.
Methods Electronic searches of Medline, EMBASE, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Database of Controlled Trials were conducted and reference lists of relevant articles were hand searched.
Results The search identified 12 primary studies documenting the use of NIV, either continuous positive airway pressure or bi-level non-invasive ventilation, for ACPO in the out-of-hospital setting. Only three studies were randomised controlled trials, with none addressing inhospital mortality as a primary outcome measure. The majority of articles were non-comparative descriptive studies.
Conclusion Early prehospital NIV appears to be a safe and feasible therapy that results in faster improvement in physiological status and may decrease the need for intubation when compared with delayed administration in the ED. There is weak evidence that is may decrease mortality. The cost versus benefit equation of system-wide prehospital implementation of NIV is unclear and, based on the current evidence, should be considered with caution.
At the same time, the National Association of EMS Physicians has published a position statement on noninvasive positive pressure ventilation, for the general indication of acute dyspnoea. It states:
The general indication for NIPPV is dyspnea accompanied by early respiratory failure in patients with intact protective airway reflexes and mental status. The majority of NIPPV studies have focused on patients with acute pulmonary edema.
However, NIPPV may prove useful with other reversible disease processes such as chronic obstructive pulmonary disease or asthma exacerbations. While utilized in in-hospital practice, the role of NIPPV for pneumonia-associated respiratory failure is less clear. While some clinicians advocate the use of NIPPV to augment oxygenation prior to ETI in the in- hospital setting, there are no studies evaluating this strategy in the prehospital setting.
The CRASH 2 trial showed improved outcomes in trauma from the administration of the antifibrinolytic drug tranexamic acid. A further analysis of the data has shown that benefit was only seen in CRASH-2 when tranexamic acid was administered within 3 hours of injury1.
An accompanying editorial2 makes the following interesting points:
Acute traumatic coagulopathy is a hyperacute process in which systemic fibrinolysis releases D-dimers that are detectable within 30 min of injury.
Those severely injured patients who develop acute coagulopathy are much more likely to die and to die early.
Once fully activated, fibrinolysis has been shown to continue unabated until endogenous antifibrinolytic elements are restored.
The earlier that tranexamic acid is administered, the more likely it might be to prevent full activation of fibrinolysis.
Hospital massive transfusion protocols incorporate fresh frozen plasma that contains all the endogenous antifibrinolytic elements in plasma and so the place for tranexamic acid in high income countries with such protocols is unclear.
The best place for tranexamic acid in developed trauma systems might actually be in the prehospital environment, where trauma bypass policies have extended prehospital times and the administration of plasma is uncommon and often impractical.
BACKGROUND: The aim of the CRASH-2 trial was to assess the effects of early administration of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage. Tranexamic acid significantly reduced all-cause mortality. Because tranexamic acid is thought to exert its effect through inhibition of fibrinolysis, we undertook exploratory analyses of its effect on death due to bleeding.
METHODS: The CRASH-2 trial was undertaken in 274 hospitals in 40 countries. 20,211 adult trauma patients with, or at risk of, significant bleeding were randomly assigned within 8 h of injury to either tranexamic acid (loading dose 1 g over 10 min followed by infusion of 1 g over 8 h) or placebo. Patients were randomly assigned by selection of the lowest numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Both participants and study staff (site investigators and trial coordinating centre staff ) were masked to treatment allocation. We examined the effect of tranexamic acid on death due to bleeding according to time to treatment, severity of haemorrhage as assessed by systolic blood pressure, Glasgow coma score (GCS), and type of injury. All analyses were by intention to treat. The trial is registered as ISRCTN86750102, ClinicalTrials.gov NCT00375258, and South African Clinical Trial Register/Department of Health DOH-27-0607-1919.
FINDINGS: 10,096 patients were allocated to tranexamic acid and 10,115 to placebo, of whom 10,060 and 10,067, respectively, were analysed. 1063 deaths (35%) were due to bleeding. We recorded strong evidence that the effect of tranexamic acid on death due to bleeding varied according to the time from injury to treatment (test for interaction p<0.0001). Early treatment (≤1 h from injury) significantly reduced the risk of death due to bleeding (198/3747 [5.3%] events in tranexamic acid group vs 286/3704 [7.7%] in placebo group; relative risk [RR] 0.68, 95% CI 0.57-0.82; p<0.0001). Treatment given between 1 and 3 h also reduced the risk of death due to bleeding (147/3037 [4.8%] vs 184/2996 [6.1%]; RR 0.79, 0.64-0.97; p=0.03). Treatment given after 3 h seemed to increase the risk of death due to bleeding (144/3272 [4.4%] vs 103/3362 [3.1%]; RR 1.44, 1.12-1.84; p=0.004). We recorded no evidence that the effect of tranexamic acid on death due to bleeding varied by systolic blood pressure, Glasgow coma score, or type of injury.
INTERPRETATION: Tranexamic acid should be given as early as possible to bleeding trauma patients. For trauma patients admitted late after injury, tranexamic acid is less effective and could be harmful.
1. The importance of early treatment with tranexamic acid in bleeding trauma patients: an exploratory analysis of the CRASH-2 randomised controlled trial Lancet. 2011 Mar 26;377(9771):1096-101
OBJECTIVE: To determine whether out-of-hospital administration of hypertonic fluids would improve survival after severe injury with hemorrhagic shock.
BACKGROUND: Hypertonic fluids have potential benefit in the resuscitation of severely injured patients because of rapid restoration of tissue perfusion, with a smaller volume, and modulation of the inflammatory response, to reduce subsequent organ injury.
METHODS: Multicenter, randomized, blinded clinical trial, May 2006 to August 2008, 114 emergency medical services agencies in North America within the Resuscitation Outcomes Consortium. Inclusion criteria: injured patients, age ≥ 15 years with hypovolemic shock (systolic blood pressure ≤ 70 mm Hg or systolic blood pressure 71-90 mm Hg with heart rate ≥ 108 beats per minute). Initial resuscitation fluid, 250 mL of either 7.5% saline per 6% dextran 70 (hypertonic saline/dextran, HSD), 7.5% saline (hypertonic saline, HS), or 0.9% saline (normal saline, NS) administered by out-of-hospital providers. Primary outcome was 28-day survival. On the recommendation of the data and safety monitoring board, the study was stopped early (23% of proposed sample size) for futility and potential safety concern.
RESULTS: A total of 853 treated patients were enrolled, among whom 62% were with blunt trauma, 38% with penetrating. There was no difference in 28-day survival-HSD: 74.5% (0.1; 95% confidence interval [CI], -7.5 to 7.8); HS: 73.0% (-1.4; 95% CI, -8.7-6.0); and NS: 74.4%, P = 0.91. There was a higher mortality for the postrandomization subgroup of patients who did not receive blood transfusions in the first 24 hours, who received hypertonic fluids compared to NS [28-day mortality-HSD: 10% (5.2; 95% CI, 0.4-10.1); HS: 12.2% (7.4; 95% CI, 2.5-12.2); and NS: 4.8%, P < 0.01].
CONCLUSION: Among injured patients with hypovolemic shock, initial resuscitation fluid treatment with either HS or HSD compared with NS, did not result in superior 28-day survival. However, interpretation of these findings is limited by the early stopping of the trial.
A substudy of a large randomised controlled trial comparing etomidate with ketamine for RSI in the pre-hospital environment, emergency department, and intensive care unit examined immediate complication rates in relation to the intubation difficulty scale score (IDS).
the Cormack grade (0–3 points, grade 1 giving no IDS points);
the intensity of lifting force required (0 points if normal, 1 point if increased);
the need to apply external laryngeal pressure (0 or 1 point, application of cricoid pressure (Sellick manoeuvre) does not alter the score)
vocal cord position (abduction, 0 points; adduction, 1 point). Each criterion was scored and recorded by the physician who performed the procedure.
The sum gives the IDS score, and a score of 0 indicates an easy tracheal intubation at the first attempt by a single operator using a single technique, with a good view of the glottis and abducted vocal cords. Intubation was considered difficult if the score was greater than 5.
There was a positive linear relationship between IDS score and complication rate, and difficult intubation appeared to be a significant independent predictor of death.
OBJECTIVES: To evaluate the association between emergency tracheal intubation difficulty and the occurrence of immediate complications and mortality, when standardised airway management is performed by emergency physicians.
METHODS: The present study was a substudy of the KETAmine SEDation (KETASED) trial, which compared morbidity and mortality after randomisation to one of two techniques for rapid sequence intubation in an emergency setting. Intubation difficulty was measured using the intubation difficulty scale (IDS) score. Complications recognised within 5min of endotracheal intubation were recorded. We used multivariate logistic regression analysis to determine the factors associated with the occurrence of complications. Finally, a Cox proportional hazards regression model was used to examine the association of difficult intubation with survival until 28 days.
RESULTS: A total of 650 patients were included, with mean age of 55±19 years. Difficult intubation (IDS >5) was recorded in 73 (11%) patients and a total of 248 complications occurred in 192 patients (30%). Patients with at least one complication had a significantly higher median IDS score than those without any complications. The occurrence of a complication was independently associated with intubation difficulty (odds ratio 5.9; 95% confidence interval (CI) [3.5;10.1], p<0.0001) after adjustment on other significant factors. There was a positive linear relationship between IDS score and complication rate (R(2)=0.83; p<0.001). The Cox model for 28-day mortality indicated that difficult intubation (hazard ratio 1.59; 95%CI [1.04;2.42], p=0.03) was a significant independent predictor of death.
CONCLUSION: Difficult intubation, measured by the IDS score, is associated with increased morbidity and mortality in patients managed under emergent conditions.
The Airtraq seems nifty when you try it on a manikin, but until now the question of whether it would be a useful pre-hospital tool was unanswered. This Austrian study provides helpful data:
OBJECTIVES: The optical Airtraq laryngoscope (Prodol Meditec, Vizcaya, Spain) has been shown to have advantages when compared with direct laryngoscopy in difficult airway patients. Furthermore, it has been suggested that it is easy to use and handle even for inexperienced advanced life support providers. As such, we sought to assess whether the Airtraq may be a reliable alternative to conventional intubation when used in the prehospital setting.
DESIGN, SETTING, AND PATIENTS: Prospective, randomized control trial in emergency patients requiring endotracheal intubation provided by anesthesiologists or emergency physicians responding with an emergency medical service helicopter or ground unit associated with the Department of Anesthesiology, General Hospital, Wiener Neustadt, Austria.
MEASUREMENTS AND MAIN RESULTS: During the 18-month study period, 212 patients were enrolled. When the Airtraq was used as first-line airway device (n=106) vs. direct laryngoscopy (n=106), success rate was 47% vs. 99%, respectively (p<.001). Reasons for failed Airtraq intubation were related to the fiber-optic characteristic of this device (i.e., impaired sight due to blood and vomitus, n=11) or to assumed handling problems (i.e., cuff damage, tube misplacement, or inappropriate visualization of the glottis, n=24). In 54 of 56 patients where Airtraq intubation failed, direct laryngoscopy was successful on the first attempt; in the remaining two and in one additional case of failed direct laryngoscopy, the airway was finally secured employing the Fastrach laryngeal mask. There was no correlation between success rates and body mass index, age, indication for airway management, emergency medical service unit, or experience of the physicians.
CONCLUSIONS: Based on these results, the use of the Airtraq laryngoscope as a primary airway device cannot be recommended in the prehospital setting without significant clinical experience obtained in the operation room. We conclude that the clinical learning process of the Airtraq laryngoscope is much longer than reported in the anesthesia literature.
The SAMU (Service d’aide médicale urgente) guys have had a run of interesting pre-hospital publications lately. In this study, one of their ultrasound-wielding physicians travelled in a car to meet comatose head injured patients in a large semi-rural territory area with up to a 120–160-min transport time to a hospital with emergency neurosurgical capability. Pre-hospital transcranial Doppler was done, the results of which appear to have influenced treatment decisions, including the pre-hospital administration of noradrenaline (norepinephrine). I think this study has answered the ‘can it be done?’ question, but further work is needed to determine whether it really makes a difference to outcome.
Background: Investigation of the feasibility and usefulness of pre-hospital transcranial Doppler (TCD) to guide early goal-directed therapy following severe traumatic brain injury (TBI). Methods: Prospective, observational study of 18 severe TBI patients during pre-hospital medical care. TCD was performed to estimate cerebral perfusion in the field and upon arrival at the Level 1 trauma centre. Specific therapy (mannitol, noradrenaline) aimed at improving cerebral perfusion was initiated if the initial TCD was abnormal (defined by a pulsatility index >1.4 and low diastolic velocity). Results: Nine patients had a normal initial TCD and nine an abnormal one, without a significant difference between groups in terms of the Glasgow Coma Scale or the mean arterial pressure. Among patients with an abnormal TCD, four presented with an initial areactive bilateral mydriasis. Therapy normalized TCD in five patients, with reversal of the initial mydriasis in two cases. Among these five patients for whom TCD was corrected, only two died within the first 48 h. All four patients for whom the TCD could not be corrected during transport died within 48 h. Only patients with an initial abnormal TCD required emergent neurosurgery (3/9). Mortality at 48 h was significantly higher for patients with an initial abnormal TCD. Conclusions: Our preliminary study suggests that TCD could be used in pre-hospital care to detect patients whose cerebral perfusion may be impaired.
British military physicians at the UK military field hospital, Camp Bastion, Helmand Province, Afghanistan, evaluated their trauma cases against these standards. It is apparent that the trauma care provided to some people in Afghanistan outclasses that delivered within much of the UK.
Background The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report on trauma management, published in 2007, defined standards for United Kingdom (UK) hospitals dealing with trauma. This study compared the NCEPOD standards with the performance of a UK military field hospital in Afghanistan. Setting UK military field hospital, Camp Bastion, Helmand Province, Afghanistan. Materials and methods Data were collected prospectively for all patients fulfilling the trauma team activation criteria during the 3 months of Operation Herrick IXa (from mid October 2008 to mid January 2009) and combined with a retrospective review of prehospital documentation, trauma resuscitation notes, operations notes and transfer notes for these patients. Results During the study period, there were 226 trauma team activations. Of those patients brought to the medical facility at Camp Bastion by UK assets, 93.7% were accompanied by a doctor with advanced airway skills, although only 6.2% of the patients required such an intervention. Consultants in emergency medicine and anaesthesia were present in 100% of cases and were directly involved (in either leading the team or performing airway management) in 63.5% and 77.6% of cases respectively. Of those patients requiring operative intervention, 98.1% had this performed by a consultant surgeon. Of those patients requiring CT, 93.6% of cases had this performed within 1 h of arrival. Conclusions Trauma patients presenting to the medical facility at Camp Bastion during Operation Herrick IXa, irrespective of their nationality or background, received a high standard of medical care when compared with the NCEPOD standards
National Confidential Enquiry into Patient Outcome and Death recommendations Pre-hospital care
All agencies involved in trauma management, including emergency medical services, should be integrated into the clinical governance programmes of a regional trauma service. Airway management in trauma patients is often challenging, and the pre-hospital response for these patients should include someone with the skill to secure the airway, (including the use of rapid sequence intubation), and maintain adequate ventilation.
A trauma team should be available 24 h a day, 7 days a week. This is an essential part of an organised trauma response system. A consultant must be the team leader for the management of the severely injured patient.
Airway and breathing
The current structure of prehospital management is insufficient. There is a high incidence of failed intubation and a high incidence of patients arriving at hospital with a partially or completely obstructed airway. Change is urgently required to provide a system that reliably provides a clear airway with good oxygenation and control of ventilation. This may be through the provision of personnel with the ability to provide anaesthesia and intubation in the prehospital phase or through the use of alternative airway devices.
Trauma laparotomy is extremely challenging and requires consultant presence within the operating theatre. If CT is to be performed, all necessary images should be obtained at the same time, and routine use of head-to-toe scanning is recommended in the adult trauma patient if no indication for immediate intervention exists.
Patients with severe head injury should have a CT of the head performed as soon as possible after admission and within 1 hour of arrival at the hospital. All patients with severe head injury should be transferred to a neurosurgical critical care centre irrespective of the requirement for surgical intervention.
There should be standardised transfer documentation of patient details, injuries, results of investigations and management, with records kept at the dispatching and receiving hospitals.
A comparison of civilian (National Confidential Enquiry into Patient Outcome and Death) trauma standards with current practice in a deployed field hospital in Afghanistan. Emerg Med J 2011;28:310-312
I published a case report in the EMJ highlighting the use of intranasal ketamine in a pre-hospital paediatric burns case.
The lad had nasty scalds but did not need iv fluids and had no other indications for an iv line. The vigorous first aid had rendered him cold and veinless and an intraosseous would have been overkill. Ketamine was perfect for the job and Ambulance Service New South Wales paramedics carry a mucosal atomisation device (MAD) for the administration of i.n. fentanyl. I used the MAD to adminster 0.5 mg/kg ketamine, but there is a dead space in the device (0.1 ml) that probably resulted in actual delivery of 0.25mg/kg. This gave great analgesia and compliance enabling us to painlessly apply polyethylene film to the burns.
I received the following email from TIm Wolfe, the inventor of the MAD nasal (reproduced with permission):
Nice contribution to the literature. There is a lot of interest in IN ketamine in these lower doses to treat pain but not cause sedation. You eluded to the military interest and the hospice interest. I think your insights for EMS are also cutting edge – hopefully this will lead others to design a larger trial.
Tim Wolfe, MD
More information on the use of intranasal medication is available at www.intranasal.net. I have no conflicts of interest to declare.
In contrast to numerous other European nations, physicians with critical care skills do not consistently form part of the emergency pre-hospital system in the UK. My colleagues and I described the level of cover provided to patients in England, Wales and Northern Ireland, now available as an open access article online.
Background Every day throughout the UK, ambulance services seek medical assistance in providing critically ill or injured patients with pre-hospital care.
Objective To identify the current availability and utilisation of physician-based pre-hospital critical care capability across England, Wales and Northern Ireland.
Design A postal and telephone survey was undertaken between April and December 2009 of all 13 regional NHS ambulance services, 17 air ambulance charities, 34 organisations affiliated to the British Association for Immediate Care and 215 type 1 emergency departments in England, Wales and Northern Ireland. The survey focused on the availability and use of physician-based pre-hospital critical care support.
Results The response rate was 100%. Although nine NHS ambulance services recorded physician attendance at 6155 incidents, few could quantify doctor availability and utilisation. All but one of the British Association for Immediate Care organisations deployed ‘only when available’ and only 45% of active doctors could provide critical care support. Eleven air ambulance services (65%) operated with a doctor but only 5 (29%) operated 7 days a week. Fifty-nine EDs (27%) had a pre-hospital team but only 5 (2%) had 24 h deployable critical care capability and none were used regularly.
Conclusion There is wide geographical and diurnal variability in availability and utilisation of physician-based pre-hospital critical care support. Only London ambulance service has access to NHS-commissioned 24 h physician-based pre-hospital critical care support. Throughout the rest of the UK, extensive use is made of volunteer doctors and charity sector providers of varying availability and capability.