Endotracheal Intubation in a Prehospital Setting - Research Paper Example

 Aims and objectives The aim of this study is to identify literature pertaining to prehospital endotracheal intubation and produce an evidence-based argument whether it is a gold standard for paramedics in an Emergency Service System. The objectives of the study are to evaluate the risks and benefits of endotracheal intubation in a prehospital setting and arrive at a conclusion weighing the pros and cons of the procedure. Material and methods Pubmed search was used to retrieve articles pertaining to this controversial topic. The MESH words used were prehospital and intubation. There were 580 results pertaining to this topic. Of these 231 papers pertained to English articles in the last ten years. Of these 228 articles, only 74 looked at intubation by paramedic personnel. 14 articles looked at the outcomes. Of these 14 articles, 13 of them mentioned about mortality in the intubated group versus non-intubated group. 9 of these demonstrated raised mortality in the intubated group and one demonstrated decreased mortality in the intubated group. 3 articles showed no difference in mortality. Also, only one paper was randomised and only 2 were prospective studies. Rest all were retrospective studies. Introduction Adequate airway management is the core of any emergency medical service, be it for trauma, or cardiac arrest, or stroke. While there are many methods to gain access to airway, endotracheal intubation allows perfect control of the breathing and respiration of a casualty. For years, prehospital intubation has been practiced by many systems of emergency medical services all over the world. Both physicians and paramedics have been performing this procedure liberally. However, recent studies have raised concerns about the safety of the procedure when performed by paramedics. Many studies have proved that endotracheal intubation, in the first place, is not the best way to gain control of airway in a prehospital setting. And, secondly, paramedics are not the best people to perform it. There is increasing evidence that intubation either offers no advantage to the outcome or may even worsen the outcome. In UK, the Joint Royal Colleges Ambulance Liaison Committee (JRCALC), which is the clinical governing body for Ambulance Service has proposed that intubation is no longer taught to paramedics and that they use supraglottic airway devices to gain control of airway in a prehospital setting (JRCALC, 2008). These recommendations have not been taken well by the paramedics associations because of lack of evidence-base for the proposal. This literature review aims at critical analysis of the recommendations set by the JRCALC on the platform of evidence-based practice. Indications for airway control in a prehospital setting Endotracheal intubation is the core of advanced trauma life support. Hypoxemia and asphyxia can result in secondary organ damage to any organ and more specifically to the cardiovascular and the central nervous systems. Hence adequate oxygenation is critical in a seriously ill patient. Most of the trauma patients are at risk for pulmonary aspiration of blood or stomach contents and hence airway control must be achieved as soon as possible. Many studies have shown that early airway control by means of endotracheal intubation improves the outcome of critically ill patients. Also intubation is promulgated as a good thing because it allows control and protection of the airway, control of breathing, delivery of 100% oxygen and prevention of hypercarbia. Methods of airway control in a prehospital setting There are many methods of gaining airway control in a prehospital setting. The easiest method is bag and mask ventilation. Other methods include supraglottic devices and endotracheal intubation. Endotracheal intubation (ETI) is a method by which a flexible plastic tube is placed into the trachea to protect the airway of the patient and to provide a means of mechanical ventilation. ETI is an invasive procedure. The trachea can be gained access though two methods namely oropharyngeal and nasopharyngeal methods. Oropharyngeal intubation is the most common method of ETI. In this procedure, the ET tube is passed through the mouth, larynx and vocal cords into the trachea. It is done with the assistance of a laryngoscope. The ET tube is secured in position by inflating the bulb. In nasopharyngeal intubation, the ET tube is passed though the nose, larynx and vocal cords into the trachea. ETI permits air to pass freely in and out of the lungs, thus ventilating them. Air can be pushed through ET either by bagging or by connecting to a ventilator. Supraglottic devices are non-invasive, in the sense they are not inserted beyond the vocal cords. There are many such devices. The commonly used ones are laryngeal tube, laryngeal masks and esophageo-tracheal bitube. Of these, laryngeal mask airway or LMA is the commonest. Other supraglottic devices are pharyngeal airway xpress, airway management device, streamlined liner of the pharyngeal airway, cobra perilaryngeal airway and iGel (Erlac et al, 2008). The platform for all airway procedures is bag and mask ventilation. It is a basic skill and involves usage of a self-inflating bag and a non-return valve attached to a mask. Risks involved in ETI ETI is a potentially dangerous invasive procedure. Inadvertent placement of the ET tube into the esophagus which is right behind the trachea can lead to inadequate respirations contributing to hypoxic brain damage, cardiac arrest and death. Stomach contents may be aspirated which can result in pneumonia, aspiration pneumonitis and acute respiratory distress syndrome. During the procedure, damage can occur to the vocal cords, cervical spine, soft tissues of the throat and even teeth. Invasive control of airway demands expertise, availability of salvage devices and appropriate monitoring. Intubation also prolongs the time spent before reaching the hospital. According to Bocchicchio et al (2003), prehospital endotracheal intubation in trauma patients without acute lethal injury only prolongs the prehospital duration and does not improve the long term outcome. Difficulties involved in prehospital ETI Pre-hospital intubation is a common life-saving procedure that is performed by the emergency medical services team. This procedure is a core skill required for effective pre-hospital trauma care. It may be carried out by paramedics or physicians. The procedure is performed in different forms by different service systems. Some perform it under good sedative and anesthetic coverage, while others, mainly paramedics perform it without drugs. It is difficult to intubate patients with intact airway reflexes without sedation, anesthetic or muscle relaxant. Prehospital airway management is difficult because of many factors. Unlike in a hospital set up, there is limited equipment, monitoring, lack of skilled help, inadequate lightening or bright lightening making laryngoscopy difficult, impaired patient access due to entrapment, anatomical reasons, hypersalivation and excessive noise. In addition to these, access to airway may be difficult because of debris, blood and vomitus (Dean, 2000). Due to these factors, prehospital intubation is difficult even for anesthetists (Dean, 2000). When this is the situation with experts, many researchers raise doubts about the effectiveness of this procedure when performed by less skilled people like paramedics. Improper attempt of intubation worsens the condition of the patient and contributes to mortality and morbidity. Errors in endotracheal intubation in a prehospital setting Common errors which can occur in endotracheal intubation are multiple attempts (4 and more than 4), ET tube misplacement or dislodgment and failed intubation on hospital arrival. These errors are affected by many clinical factors like age and sex of the patient, cardiac status of the patient, medical condition and also the extent of trauma in the patient. The estimated per service error rates are anywhere between 0% to 40%. The error rates are higher in children less than 6 years of age, in those who do not have cardiac arrest, in those who have suffered extensive trauma and in those receiving sedation-facilitated or conventional intubation (Wang et al, 2005). Factors which influence the outcome 1. Expertise: Expertise does not necessarily depend on whether the person is a physician or a paramedic. The physician may be a fully trained anesthetist, who is performing intubation on a day-to-day basis, or is an anesthetist trainee with 1, 2 or 5 years experience, or is an emergency physician with limited knowledge and experience about intubation or may even be a general practitioner who has not performed intubations for years. On the other hand, the paramedic may be a nurse who has worked in critical care units for several years with good skills and expertise to intubate properly. Or, the paramedic may be a technician or a trainee nurse with limited exposure to intubation. Thus, even in the two groups, expertise may very significantly. Competency in clinical practice is dependent on the standard and content of the training imparted in clinical skills. It is obvious that poor training and insufficient knowledge will result in improper and erratic clinical practice. 2. Indications for intubation: Hypotension, hypoxia and hypercarbia are common in any emergency setting like trauma, stroke and cardiac arrest. These factors contribute to secondary organ damage when not handled properly. Indication for intubation in trauma patients varies from system to system. While some follow the protocol of intubating all patients with Glascow Coma Scale (GCS) 8 or less, others intubate when the score is 8 or more in combative patients. These indications contribute to the outcome. Studies have shown that unnecessary interventions like ETI and positive pressure ventilation can cause damage to other organs like heart and kidney and worsen the prognosis. 3. Hospital- based care: The standard of care that is provided after the patient is admitted into the hospital also influences the outcome of prehospital intubation. Controversy involved in prehospital intubation Prehospital ETI is a controversial topic with many studies pouring in information either supporting this procedure or condemning it. This is mainly because recent evidence has shown the futility of this invasive procedure when performed in the rugged conditions of prehospital setting. The controversy also evokes some territorial conflict between the physicians and the paramedics as to who is the best person to perform the procedure. Because this procedure for a long time was used as a life-saving stunt by both paramedics and physicians, preventing the paramedics from doing it from now on can make emotions run high and create strong feelings. The controversy involves not only in those who are traumatized but also in cardiac arrest cases. This is because; many observational studies have confirmed lack of survival benefit from intubation in these cases. And infact, many EMS systems have seen decrease in cardiac arrest survivals after widespread introduction of endotracheal intubations. There are no clear reasons behind these observations. The most probable reason is fall of blood flow during cardio-pulmonary resuscitation when there is positive pressure in chest. Studies which prove that prehospital ETI has worse outcomes One of the major causes of prehospital morbidity and mortality is inadequate management of airway. It has been estimated that upto 85% of deaths in major trauma cases are because of airway obstruction (Helm et al, 2006). There are quite a few studies which have been conducted to evaluate the need for prehospital endotracheal intubation in major trauma cases needing airway control. Wang et al (2004) conducted a retrospective cohort study in USA. The group studied all trauma patients with severe traumatic brain injury beyond 18 years of age retrospectively and compared the outcomes of prehospital intubation versus hospital intubation in terms of mortality, neurologic outcome and functional impairment. Their study concluded that outcomes in prehospital intubated cases were worse when compared to hospital-intubated cases. This study however had many flaws. First of all, it was a non-randomized study. It used pre-existing and invalidated registry and functional impairment score. There was no information of the course of emergency department airway care. Confounding factors that could affect prehospital intubation were not adjusted. The study also did not attempt to identify the failed efforts of prehospital intubation. Though analysis and propensity scores were used, matching techniques were not applied properly. Stockinger and McSwain (2004) study also was a retrospective one conducted in the US. They reviewed records about patients who met with level1 trauma criteria and who received ETI or bag and mask ventilation. Their study concluded that the mortality rates in patients receiving ETI and bag and mask ventilation was high (68%). Also the mortality in those with ETI was much higher than compared to mortality in those who received bag and mask ventilation. The limitations of this study were that the study was an uncontrolled study with retrospective design. Also, the number of survivals in ETI group was so small that it was difficult to compare the outcomes. Davis et al (2003) also conducted a similar study but with prospective design. They studied 209 patients who received prehospital intubation and matched them with historical controls who did not. Their study showed a high mortality rate of 33% in those who were intubated in a prehospital setting when compared to the mortality rate of 24.2% in those who received bag and mask until they reached hospital. Also, the good outcomes in ETI were much lower when compared to the outcomes in bag and mask ventilation cases. However, after arrival to the hospital, the total days in hospital and ICU were similar in both the groups. This study has significant points to contribute for discussion. First of all, it is a cohort study with good matching of controls and cohorts. Rapid sequence intubation cohorts had significantly low pCO2, probably because of hyperventilation, and this might have contributed to increased mortality. Study by Bochicchio et al (2003) was a prospective study with data collected on 191 patients who had a GCS score of 8 or less than 8 and a head Abbreviated Injury Scale of 3 or more than 3. Of these, 78 were intubated in a prehospital setting and 113 were intubated after arrival to the hospital. The prospective cohort study compared these 2 groups. The study concluded that the dispatch time in prehospital ETI was much higher than the controls. Also, poor outcomes and other complications like respiratory complications and longer stay in ICU were seen in the field ETI group. Christensen and Hoyer (2003) conducted a retrospective study in Denmark and evaluated the mortality rates in those who underwent prehospital ETI. Their study concluded that this group had higher mortality rates and poorer neurological outcomes. Similar study was conducted by Sloane et al (2000) in the US. This study was a retrospective study. The researchers reviewed all adult trauma patients who underwent rapid sequence intubation in a prehospital setting and compared them to those who underwent the same procedure after arrival at the hospital. The success rates of intubation and the number of attempts in both groups were similar. However, transit time increased because of field ETI, thus taking away valuable time of quality resuscitation. The respiratory complications in prehospital intubations were much higher when compared to the control group. However, there were no significant differences in the length of stay in the ICU and hospital in both the groups. The limitations of this study were that there was no blinding of the data collector, the sample of prehospital ETI patients was small and those who underwent prehospital intubation had worse trauma score. Hence the outcomes in both the groups cannot be compared. According to the study by Eckstein et al (2000) which is also a retrospective study, the mortality in ETI when compared to bag-mask ventilation is higher and the transit time also is longer in the first group. Murray et al (2000) and Davis et al (2005) also reported increased mortality in those who underwent prehospital ETI when compared to those who were not intubated. In about one fouth of the patients intubation failure is most likely due to combative patients or gagging (Karch et al, 2001). After reviewing all these studies it can be said that prehospital intubation is associated with increased mortality, longer transit times, increased respiratory complications and probably less good outcome. However these studies have their own limitations and hence don’t add much value for evidence based practice. All these studies are either prospective or retrospective studies. To consider what articles must be included in the review to make the review more authentic and reliable, knowledge on the different levels of accorded studies is essential. The different levels of studies are called hierarchy. Hierarchy provides a confidence measure to the end-user (Evans, 2003). According to Evans (2003), random control trials can be considered of good standard and they are infact labeled as the gold standard of research for providing optimal research designs to answer pertinent questions. However, systemic reviews and meta-analysis have topped the hierarchy list. The various studies which have proved the inefficiency of prehospital intubation are not comparable to each other. First of all, none of the studies are randomized control studies. Secondly, the studies are of small size. Thirdly, the clinical skills of the persons performing the procedure is variable. Fourthly, the protocols and indications for intubation are different for different systems. Also, some intubations are drug-assisted and some others are not. It is difficult to design controlled trials in this case both due to practical reasons and ethical issues. Also, those who were intubated were probably more serious than who could reach the hospital and got intubated there. As such, intubation does not change the inherent mortality rate and ability to intubate without drugs is a marker of mortality. It is actually not yet clear whether the rise in mortality due to prehospital intubation represents a form of selection bias or is a result of true detrimental effect of early intubation on the outcome. There is no proper evidence-based practice applied for prehospital intubation. This is because there are not many studies pertaining to this field. Whatever few available are either of variable quality or difficult to interpret. It is not practical and cannot be approved ethically to perform studies on patients with severe injuries about the deleterious effects of hypoxemia when left unintubated and compared with those who were intubated in a timely manner. Key issues which are a matter of concern in prehospital intubation are: 1. Were any drugs used to sedate, anesthetize and paralyze the patient prior to intubation and if so what drugs were used? 2. Who performed the intubation? What are his/her qualifications, experience, skills, background and expertise? 3. Whether the procedure was performed in the aeromedical system or ground base? 4. What were the indications for intubations and how nay attempts were made to gain success? 5. What was the patient case mix? 6. What level of care was provided to the patient once he was admiitted? Detrimental effects of positive pressure ventilation (PPV) Many studies are now pointing out to the detrimental effects of PPV as a causative factor for poor outcome associated with some prehospital intubations. Outside the hospital, it is difficult to monitor how much pressure is being given by bag and mask. The bad effects of PPV are (Suter and Wolff, 1982): 1. High endotracheal pressure in turn causes increased pressure in the pleural space, thus opposing venous return and decreasing cardiac filling and output. 2. Continuous PPV impairs venous return, indicating that high intrathoracic pressure is detrimental to renal function. 3. Positive End Expiratory Pressure or PEEP alters blood flow distribution and tissue oxygenation. Is bag and mask ventilation superior to ETI? ETI is an advanced procedure demanding skilled personnel to perform it. Failed intubation and misplaced tubes can result in significant morbidity and mortality. At this juncture, one must note that what patients need is oxygenation. Common sense tells that adequate bag and mask ventilation is clearly more superior to failed or misplaced intubation. What about Rapid Sequence Intubation or RSI in a Prehospital Setting? RSI has been in vogue for almost 20 years. There is not much concrete data on RSI to comment on it in a prehospital setting. Whatever studies have been performed on it are scattered in many specialty journals. RSI has many theoretical benefits. It improves oxygenation and ventilation; it protects the airway from aspiration and decompensation and also protects the spine through sedation and paralysis. It decreases the number of failed intubations. A recent study by Wang et al (2005) identified 2 important factors associated with intubation: trismus and intact gag reflex. Both these factors can be taken care of in RSI. The main risks associated with this procedure are inability to intubate and ventilate after administration of neuromuscular agent, and prolongation of the transit time. Neuromuscular blockade removes whatever little respiratory effort and hence after this is achieved, intubation and ventilation is a must. Bernard et al (2006) added that use in inappropriate situations and also costs of training to the providers are other disadvantages of this procedure. Most of the studies pertaining to RSI are on aeromedical crews. This is because, the personnel operating these systems are highly qualified and are in a position to apply such complex and advanced procedures. In majority of the cases RSI was successful with minimal intubation efforts. Reports from the crew members suggest that RSI was inevitable in majority of the cases to gain chemical control of the persons so that the journey to the hospital was safe. RSI is associated with some short term complications like esophageal intubation, multiple attempts, aspiration and also cardiac rhythm changes including arrhythmias. The patient can also suffer from adverse effects of the drugs used. Studies favoring prehospital intubation There are very few studies which have demonstrated the benefits of prehospital intubation in trauma cases. Winchell and Hoyt (1997) conducted a retrospective analysis and reported that prehospital intubation decreased the mortality rate in patients with multiple trauma from 36% to 26%. In those with severe trauma of the brain, prehospital intubation decreased the mortality rate from a whopping 49% to 23%. The limitations of this study are that though the patients were stratified by GCS score, they were not adjusted for some potentially important factors like Abbreviated Injury Scale of head and neck, Injury Severity Score and hypotension. Another limiting factor in this study is that the rate of intubation was higher in those with GCS scores 4 to 8 than GCS scores 3, pointing towards some bias factor. Why target paramedics for poor success of prehospital intubation? Most of the studies conducted on prehospital intubation are from US. In the US, the emergency systems are mainly paramedic-based. Paramedics are not in a position to administer dangerous drugs like sedatives, anesthetics and smooth muscle relaxants. The success rate of intubation depends a lot on the relaxed condition of the patient. This is because, anybody with GCS more than 3 is likely to have laryngeal reflexes that fight intubation and considering the adverse conditions in a prehospital setting, the chances of correct intubation and proper positioning is difficult. Drugs diminish these reflexes and allow easy intubation. As per available data through studies, the success rates for tracheal intubation of trauma patients without drugs varies between 49- 71% and the success depends on the expertise of the person performing the procedure. The success rate increases to about 90% when benzodiazepine is given to the patient just prior to intubation and this rate almost touches 100% when neuromuscular blocking agent is given (Lockey et al, 2004). Should prehospital intubation procedure be withdrawn from paramedic- ambulance services? As discussed before, there is no evidence-based practice for such a proposal. Most of the studies which have concluded higher mortality rates are indeed paramedic based. But the studies are small and mostly non-randomized and hence don’t add much value to evidence-based practice. There are no studies which compare the efficiencies of physician intubation and paramedic intubation. Ideally such a study would give good platform for evidence based practice. Also, the intubated patients are probably destined to have high mortality by virtue of serious damage that has already occurred before the paramedic has taken over the patient. There are no studies which show that paramedics err more during intubations. The only reason why paramedics are cornered in this topic are because cannot give drugs for intubation. As discussed before, expertise does not necessarily depend on whether the performer is paramedic or physician. Helm et al (2005) evaluated the success rate of prehospital endotracheal intubation in physician- based EMS system. They conducted the study on German Helicopter Emergency Medical Service (HEMS) system. The study reported that the overall success rate of endotracheal intubation was 100% with first attempt being successful in 87.4% cases. However, this study cannot be used as a model for all physician based emergency systems. This is because, the study was conducted on a aero-emergency system which is mainly used for very serious patients and because of the nature of emergency, anesthetists were employed for resuscitation. Naturally, by virtue of their day-to-day job, anesthetists are experts in intubation and they do it by giving drugs. Hence quoting Helm et al study makes no sense. Keeping all the above facts in mind, it can be said that withdrawing an intervention is not the way to address deficiencies in performance. Deficiencies in practice occur due to improper or inadequate training methods. Imparting proper education and giving adequate scope to practice can improve the quality of performance. As far as intubation is concerned, there are not many opportunities for prehospital practitioners for initial and ongoing training in anesthetic departments. However, recent sophisticated manikins give ample opportunity to learn and become an expert in intubation. Infact, experts feel that these manikins are more of experience value that relaxed anesthetic patients in the hospital. The equipment given to paramedics is different when compared to physicians. Many paramedics in UK do not have access to certain intubation adjuncts like gum-elastic bougie, McCoy laryngoscope and stylet. These adjuncts help in better visualization of the glottis which is very important for proper positioning of the endotracheal tube, more so in adverse situations as might be the case in prehospital setting. These instruments are used by most of the anesthetists but many paramedics are either not supplied with these adjuncts or are not trained in using them. Clinical competence can be achieved by practice. Since intubation is a complex intervention, especially in an out of hospital set up, quality of this intervention can be improved by limiting the procedure to practitioners who meet minimum experience standards as far as the procedure is concerned. This was demonstrated by an interesting study by Wang et al (2007). These authors extracted data on 11,771 intubations from a Pennysylvia database and determined the effects of imposing minimum experience standards for performance of intubation. According to the authors "if performance of intubation were limited to providers with a minimum of 3, 5, 10, and 15 intubations per year, the number of intubations performed would be reduced by 12%, 32%, 79%, and 98%, respectively. If performance were limited to emergency medical services agencies with a minimum of 20, 30, 50, 100, and 150 intubations per year, then the number of intubations would be reduced by 15%, 27%, 41%, 65%, and 73%, respectively." Since the success of intubation largely depends on the administration of drugs, training paramedics in rapid sequence intubation may improve the success rates. Wayne and Friedman (1999) conducted a retrospective study over a 20 year period and demonstrated high success rates of RSI. The procedure was performed by paramedics who were extensively trained in a class room followed by practical experience of atleast 20 intubations in the operating room under the expert supervision of an experienced anesthesiologist before they received certification. Post-certification, the paramedics needed to intubate atleast one patient monthly for 3 years followed by one patient a quarter. The success rate of RSI in this study was 95.5%. The paramedics were also taught how to mange failed intubations with surgical airway, bag-valve-mask and combitube. Similar reports were presented by Pace et al (2000). In this prospective study, the paramedics received a 7 hour course on RSI and 3 attempts were allowed before the insertion of combitube. The success rate of intubation was 84%. All the esophageal intubations were identified and removed in the prehospital setting itself. Though RSI plays a critical role in prehospital airway management, the precise fit of this procedure in the protocol of management of prehospital airway control is yet unclear Clinical incompetence or unaided competence? An important aspect of training is the methods paramedics have been taught to position and confirm the place of endotracheal tube. Many UK paramedics do not have access to many useful adjuncts to assist larynoscope. Light needs to be thorwn on this fact because visualization is more difficult in a prehospital setting than in a hospital. Misplacement of tubes can be avoided by allowing paramedics to access quantitative end-tidal CO2 monitors and encouraging them to use them regularly. Both anesthetists and physicians use these aids, but paramedics are not allowed to use It is important to recognize esophageal intubation as early as possible to prevent adverse effects of erratic intubation. Though proper positioning of ET tube can be confirmed with direct visualisation, auscultation of breath sounds, chest rise response to bagging and tube condensation, these clinical methods are not always reliable. Common sense says that not allowing to use the aids and faltered results because of it cannot be called clinical incompetence. This is because; use of these aids drops the misplacement rates to 0%. Jemmet et al (2003) and Katz and Falk (2001) reported endorsement of end-tidal carbon-di-oxide detectors, by most major emergency medical systems involved in the management of airway. At this juncture, it is worth mentioning that waveform ETCO2 monitors are better than CO2 detector devices. In addition to CO2 monitors, in cardiac arrest patients, conjunction use of esophageal detector devices help confirm tracheal tube placement, because in these patients, lung perfusion may be so low that CO2 monitors may not be able to pick up low CO2. One step ahead of these devices is employment of continuous waveform capnography to provide a waveform and also a quantitative numeric value of CO2. Sivestri et al (2005) reported fall in esophageal intubations to zero after using capnography. Other than these issues, paramedics must also be given access to modern aids of intubation like laryngeal airway mask. McCall et al (2008) reported that intubating using laryngeal mask by paramedics can result in improvements in the first-time intubation rates when compared with standard laryngoscopy. Another such modern device is the Airtraq laryngoscope which improves performance by pre-hospital practitioners with minimal training and experience. This device reduces training load and is found beneficial even in difficult intubations (Maharaj et al, 2006). Conclusion Prehospital intubation is a common intervention in emergency situations. It is performed by both paramedic-based services and physician-based services. For a long time, ETI was considered a gold standard for airway management in trauma and cardiac arrest cases. However, recent studies have pointed to the lacunae involved with this procedure. ETI in a prehospital setting is difficult to perform, increases the mortality rate and contributes to poor outcome. Whether the poor outcome is because of the patient’s condition itself, or is it because of the type of personnel performing it is yet unclear. References Adnet, F., Jouriles, N.J., Le Toumelin, P., et al. (1998). Survey of out-of-hospital emergency intubations in the French prehospital medical system: a multicenter study. Ann Emerg Med, 32, 454-460. Bernard, A., Handel, D., Locasto, D. (2008). Prehospital rapid sequence intubation. EMS Responder. Retrieved on 6th March, 2009 from http://publicsafety.com/article/article.jsp?id=2716&siteSection=12 Bochicchio, G.V., Ilahi, O., Joshi, M., et al. (2003). Endotracheal intubation in the field does not improve outcome in trauma patients who present without an acutely lethal traumatic brain injury. J Trauma, 54, 307-311. Callaham, M. (1997). Quantifying the scanty science of prehospital emergency care. Ann Emerg Med, 30, 785- 790. Christensen, E.F., and Hoyer, C.C. (2003). Prehospital tracheal intubation in severely injured patients: a Danish observational study. BMJ, 327, 533-534. Dawes, R.J. (2006). Prehospital intubation: deliving deeper into eveidence. Emergency Medicine Journal, 23, 740. Davis, D.P., Ochs, M., Hoyt, D.B., et al. (2003). Paramedic-administered neuromuscular blockade improves prehospital intubation success in severely head-injured patients. J Trauma, 55, 713-719. Deakin, C.D. (2003). Anaesthetists are best people to provide pre-hospital airway management. Br Med J, 320, 1006. Davis, D.P, Peay, J., Sise, M.J. et al. (2005). The impact of prehospital endotgracheal intubation on outcome in moderate to severe traumatic brain injury. J Trauma Infect Crit Care, 58, 933–9. Eckstein, M., Chan, L., Schneir, A., Palmer, R. (2000). Effect of prehospital advanced life support on outcomes of major trauma patients. Journal of Trauma, Injury, Infection and Critical Care, 48(4), 643-8. Erlac, P.B., Yldmo, P.K.H., Ongstad, P.K. (2008). Pre-hospital airway management: guidelines from a task force from the Scandinavian Society for Anaesthesiology and Intensive Care Medicine. Acta Anaesthesiol Scand., 52, 897–907. Evans, D., 2003. Hierarchy of evidence: a framework for ranking evidence evaluating healthcare interventions. Journal of Clinical Nursing, 12(1), 77 – 84. Helm, M., Hossfeld, B., Schafer, S., Hoitz, J., and Lamol, L. (2006). Factors influencing emergency intubation in the pre-hospital setting—a multicentre study in the German Helicopter Emergency Medical Service. British Journal of Anesthesia, 96(1), 67- 71. JRCALC. (2008). Airway management – JRCALC recommendations July 2008. retrieved on 10th March, 2009 from http://www.jrcalc.org.uk/airwayfeedback.pdf Jemmett, M.E., Kendal, K.M., Fourre, M.W., Burton, J.H. (2003). Unrecognized misplacement of endotracheal tubes in a mixed urban to rural emergency medical services setting. Acad Emerg Med., 10, 961 – 965. Katz, S.H., Falk, J.L. (2001). Misplaced endotracheal tubes by paramedics in an urban emergency medical services system. Ann Emerg Med, 37, 32 – 37. Karch, S.B., Lewis, T., Young, S. (2001). Field intubation of trauma patients: complications, indications and outcomes. Am J Emerg Med, 37, 32–7. Koenig, K.L. (2007). Adult Prehospital Intubation: More Harm Than Good? Journal Watch. Retrieved on 9th March, 2009 from http://emergency-medicine.jwatch.org/cgi/content/full/2007/615/1 Lockey, D., Hardy, R., and Davies, G. (2004). Pre-hospital intubation in trauma patients: Essential practice or overrated intervention? Scand J Trauma Emerg Med, 74- 77. Lockey, D., Davies, G., Coats, T. (2001). An observational study of the survival of trauma patients who have pre-hospital tracheal intubation without anesthesia or muscle relaxants. Chest trauma, 6, 78- 79. Maharaj, C.H., Costello, J.F., Higgins, T.G. et al. (2006). Learning and performance of tracheal intubation by novice personnel: a comparison of the Airtraq and Macintosh laryngoscope. Anaesthesia, 61(7), 671-7. McCall, M.J., Reeves, M., Skinner, M., et al. (2008). Paramedic tracheal intubation using the intubating laryngeal mask airway. Prehosp Emerg Care, 12(1), 30-4. Murray, J.A., Demetriades, D., Berne, T.V., et al. (2000). Prehospital intubation in patients with severe head injury. Journal of Trauma, Injury, Infection and Critical Care, 49, 1065-1070. Nicholl, J., Hughes, S., Dixon, S. (1998). The costs and benefits of paramedic skills in pre-hospital trauma care. Health Technol Assess, 2, 10–5. Pace, S.A., and Fuller, F.P. (2000). Out-of-hospital succinylcholine-assisted endotracheal intubation by paramedics. Ann Emerg Med, 35, 568 – 572. Sloane, C., Vilke, G.M., Chan, T.C., et al (2000). Rapid sequence intubation in the field versus hospital in trauma patients. J Emerg Med, 19, 259-264. Silvestri, S., Ralls, G.A., Krauss, B, et.al. (2005). The effectiveness of out-of-hospital use of continuous end-tidal carbon dioxide monitoring on the rate of unrecognized misplaced intubation within a regional emergency medical services system. Ann Emerg Med, 45, 487 – 503. Stockinger, Z.T., and McSwain, N.E. Jr. (2004). Prehospital Endotracheal intubation for trauma does not improve survival over bag-valve-mask ventilation. Journal of Trauma, Injury Infection & Critical Care, 56(3), 531-6. Suter, P., and Wolff, G. (1982). Positive pressure Ventilation and the Function of Other Organs. Intensive Care Medicine, 8, 52. Wayne, M.A., and Friedland, E. (1999). Prehospital use of succinylcholine: A 20-year review. Prehosp Emerg Med, 3, 107 – 109. Wang, H. , Lave, J. , Sirio, C. and Yealy, D. (2005). "Errors in Prehospital Endotracheal Intubation" Paper presented at the annual meeting of the National Association of EMS Physicians, Registry Resort, Naples, FL Retrieved on 10th March, 2009 from http://www.allacademic.com/meta/p55961_index.html Wang, H.E., Davis, D.P., Waye, M.A., Delbridge, T. (2004). Prehospital rapid-sequence intubation: What does the evidence show? Prehosp Emerg Care, 8, 388 – 398. Wang, H.E, Abo, B.N., Lave, J.R., Yealy, D.M. (2007). How would minimum experience standards affect the distribution of out-of-hospital endotracheal intubations? Ann Emerg Med., 50(3), 246-52. Winchell, R.J., Hoyt, D.B. (1997). Endotracheal in the field improves survival in patients with severe head injury. Arch Surg, 132, 592–7. Read More