Prehospital rapid-sequence intubation

Emergency induction of anaesthesia in the prehospital setting: a review of the anaesthetic induction agents

The standard of prehospital care is improving in many trauma systems around the world. For patients surviving the primary injury, the optimal prehospital interven tions remain debatable. Current evidence suggests that patients with severe head injury may benefit from advanced airway management, most commonly per formed by rapid sequence induction of anaesthesia and orotracheal intubation. The ‘best choice’ induction agent remains unclear, and choice seems to depend on local preferences and the skill mix of the prehospital care team. In this review we look at the recent evidence for selected hypnotic agents.

Pre-hospital anaesthesia: the same but different

Advanced airway management is one of the most controversial areas of pre-hospital trauma care and is carried out by different providers using different techniques in different Emergency Medical Services systems. Pre-hospital anaesthesia is the standard of care for trauma patients arriving in the emergency department with airway compromise. A small proportion of severely injured patients who cannot be managed with basic airway management require pre-hospital anaesthesia to avoid death or hypoxic brain injury. The evidence base for advanced airway management is inconsistent, contradictory and rarely reports all key data. There is evidence that poorly performed advanced airway management is harmful and that less-experienced providers have higher intubation failure rates and complication rates. International guidelines carry many common messages about the system requirements for the practice of advanced airway management. Pre-hospital rapid sequence induction (RSI) should be practiced to the same standard as emergency department RSI. Many in-hospital standards such as monitoring, equipment, and provider competence can be achieved. Pre-hospital and emergency in-hospital RSI has been modified from standard RSI techniques to improve patient safety, physiological disturbance, and practicality. Examples include the use of opioids and long-acting neuromuscular blocking agents, ventilation before intubation, and the early release of cricoid pressure to improve laryngoscopic view. Pre-hospital RSI is indicated in a small proportion of trauma patients. Where pre-hospital anaesthesia cannot be carried out to a high standard by competent providers, excellent quality basic airway management should be the mainstay of management.

Refraining from pre-hospital advanced airway management: a prospective observational study of critical decision making in an anaesthesiologist-staffed pre-hospital critical care service

Introduction

We report prospectively recorded observational data from consecutive cases in which the attending pre-hospital critical care anaesthesiologist considered performing pre-hospital advanced airway management but decided to withhold such interventions.

Materials and methods

Anaesthesiologists from eight pre-hospital critical care teams in the Central Denmark Region (a mixed rural and urban region with 1.27 million inhabitants) registered data from February 1^st 2011 to October 31^st 2012. Included were patients of all ages for whom pre-hospital advanced airway management were considered but not performed. The main objectives were to investigate (1) the pre-hospital critical care anaesthesiologists’ reasons for considering performing pre-hospital advanced airway management in this group of patients (2) the pre-hospital critical care anaesthesiologists’ reasons for not performing pre-hospital advanced airway management (3) the methods used to treat these patients (4) the incidence of complications related to pre-hospital advanced airway management not being performed.

Results

We registered data from 1081 cases in which the pre-hospital critical care anaesthesiologists’ considered performing pre-hospital advanced airway management. The anaesthesiologists decided to withhold pre-hospital advanced airway management in 32.1% of these cases (n = 347). In 75.1% of these cases (n = 257) pre-hospital advanced airway management were withheld because of the patient’s condition and in 30.8% (n = 107) because of patient co-morbidity. The most frequently used alternative treatment was bag-mask ventilation, used in 82.7% of the cases (n = 287). Immediate complications related to the decision of not performing pre-hospital advanced airway management occurred in 0.6% of the cases (n = 2).

Conclusion

We have illustrated the complexity of the critical decision-making associated with pre-hospital advanced airway management. This study is the first to identify the most common reasons why pre-hospital critical care anaesthesiologists sometimes choose to abstain from pre-hospital advanced airway management as well as the alternative treatment methods used.

Patient safety in pre-hospital emergency tracheal intubation: a comprehensive meta-analysis of the intubation success rates of EMS providers

Introduction

Pre-hospital airway management is a controversial subject, but there is general agreement that a small number of seriously ill or injured patients require urgent emergency tracheal intubation (ETI) and ventilation. Many European emergency medical services (EMS) systems provide physicians to care for these patients while other systems rely on paramedics (or, rarely, nurses). The ETI success rate is an important measure of provider and EMS system success and a marker of patient safety.

Methods

We conducted a systematic search of Medline and EMBASE to identify all of the published original English-language articles reporting pre-hospital ETI in adult patients. We selected all of the studies that reported ETI success rates and extracted information on the number of attempted and successful ETIs, type of provider, level of ETI training and the availability of drugs on scene. We calculated the overall success rate using meta-analysis and assessed the relationships between the ETI success rate and type of provider and between the ETI success rate and the types of drugs available on the scene.

Results

From 1,070 studies initially retrieved, we identified 58 original studies meeting the selection criteria. Sixty-four per cent of the non-physician-manned services and 54% of the physician-manned services reported ETI success rates but the success rate reporting was incomplete in three studies from non-physician-manned services. Median success rate was 0.905 (0.491, 1.000). In a weighted linear regression analysis, physicians as providers were significantly associated with increased success rates, 0.092 (P = 0.0345). In the non-physician group, the use of drug-assisted intubation significantly increased the success rates. All physicians had access to traditional rapid sequence induction (RSI) and, comparing these to non-physicians using muscle paralytics or a traditional RSI, there still was a significant difference in success rate in favour of physicians, 0.991 and 0.955, respectively (P = 0.047).

Conclusions

This comprehensive meta-analysis suggests that physicians have significantly fewer pre-hospital ETI failures overall than non-physicians. This finding, which remains true when the non-physicians administer muscle paralytics or RSI, raises significant patient safety issues. In the absence of pre-hospital physicians, conducting basic or advanced airway techniques other than ETI should be strongly considered.

Thirteen survivors of prehospital thoracotomy for penetrating trauma: a prehospital physician-performed resuscitation procedure that can yield good results

BACKGROUND

Prehospital cardiac arrest associated with trauma almost always results in death. A case of survival after prehospital thoracotomy was published in 1994 and several others have followed. This article describes the result of prehospital thoracotomy in a physician-led system for patients with stab wounds to the chest who suffered cardiac arrest on scene.

METHODS

A 15-year retrospective prehospital trauma database review identified victims of stab wounds to the chest who suffered cardiac arrest on scene and had thoracotomy performed according to local standard operating procedures.

RESULTS

Overall, 71 patients met inclusion criteria. Thirteen patients (18%) survived to hospital discharge. Neurologic outcome was good in 11 patients and poor in 2. Presenting cardiac rhythm was asystole in four patients, pulseless electrical activity in five, and unrecorded in the remaining four. All survivors had cardiac tamponade. The medical team was present at the time of cardiac arrest for six survivors (good neurologic outcome): arrived in the first 5 minutes after arrest in three patients (all good neurologic outcome), arrived 5 minutes to 10 minutes after arrest in two patients (one poor neurologic outcome), and in one patient (poor neurologic outcome) the period was unknown. Of the survivors, seven thoracotomies were performed by emergency physicians and six by anesthesiologists.

CONCLUSIONS

Prehospital thoracotomy is a well-established procedure in this physician-led prehospital service. Results from this and other similar systems suggest that when performed for the subgroup of patients described, significant numbers of survivors with good neurologic outcome can be expected.

EMS-physicians' self reported airway management training and expertise; a descriptive study from the Central Region of Denmark

Background

Prehospital advanced airway management, including prehospital endotracheal intubation is challenging and recent papers have addressed the need for proper training, skill maintenance and quality control for emergency medical service personnel. The aim of this study was to provide data regarding airway management-training and expertise from the regional physician-staffed emergency medical service (EMS).

Methods

The EMS in this part of The Central Region of Denmark is a two tiered system. The second tier comprises physician staffed Mobile Emergency Care Units. The medical directors of the programs supplied system data. A questionnaire addressing airway management experience, training and knowledge was sent to the EMS-physicians.

Results

There are no specific guidelines, standard operating procedures or standardised program for obtaining and maintaining skills regarding prehospital advanced airway management in the schemes covered by this study. 53/67 physicians responded; 98,1% were specialists in anesthesiology, with an average of 17,6 years of experience in anesthesiology, and 7,2 years experience as EMS-physicians. 84,9% reported having attended life support course(s), 64,2% an advanced airway management course. 24,5% fulfilled the curriculum suggested for Danish EMS physicians. 47,2% had encountered a difficult or impossible PHETI, most commonly in a patient in cardiac arrest or a trauma patient. Only 20,8% of the physicians were completely familiar with what back-up devices were available for airway management.

Conclusions

In this, the first Danish study of prehospital advanced airway management, we found a high degree of experience, education and training among the EMS-physicians, but their equipment awareness was limited. Check-outs, guidelines, standard operating procedures and other quality control measures may be needed.

Effect of intensive physician oversight on a prehospital rapid-sequence intubation program

OBJECTIVE

To examine the effects of adding close concurrent and retrospective physician oversight, consistent with National Association of EMS Physicians (NAEMSP) recommendations, to an existing regional prehospital rapid-sequence intubation (RSI) program.

METHODS

This study involved a retrospective cohort of patients receiving RSI between January 1, 2004, and July 31, 2008. On January 1, 2007, an updated program including additional concurrent and retrospective physician oversight, increased RSI-specific continuing medical education, and cadaver laboratory training was implemented. Study patients were divided into a preintervention group (group 1) and a postintervention group (group 2) based on date of medical care. Data regarding baseline characteristics, airway management, medication usage, and performance factors were compared between the groups. A retrospective review by two emergency medical services (EMS) physicians assessed whether the RSI was "clearly indicated" based on a predetermined set of criteria.

RESULTS

There were 109 RSIs performed in group 1 and 54 in group 2. Absolute increases in the use of both basic life support (BLS) (5%, p = 0.2) and advanced life support (ALS) (41%, p = 0.001) airway techniques were observed. Increases in postintubation administration of midazolam (30%, p = 0.001) and morphine (24%, p = 0.001) and a decrease for vecuronium (-28%, p = 0.001) were observed. There was no statistically significant difference in the intubation success rates (92% vs. 94%) and the frequencies of recognized esophageal endotracheal tube (ETT) placement (5% vs. 6%). The number of unrecognized esophageal ETT placements remained zero. Physician chart review demonstrated an absolute increase in "clearly indicated" RSIs (17%, p = 0.01).

CONCLUSIONS

Close concurrent and retrospective physician oversight consistent with recommendations from the NAEMSP is associated with improved cognitive skills in paramedics, including appropriate patient selection for RSI. Further research is warranted to validate this model and optimize where resources are best used to enhance patient safety and improve clinical management for this controversial paramedic skill.

Incidence of adverse events during prehospital rapid sequence intubation: a review of one year on the London Helicopter Emergency Medical Service

BACKGROUND

To establish the incidence of hypoxemia and hypotension during prehospital rapid sequence intubation (RSI) in trauma patients attended by the London Helicopter Emergency Medical Service (HEMS) and to compare it with historical control data from published studies of both hospital and prehospital RSI.

METHODS

A retrospective observational study during a 12-month period of London HEMS. All mission reports from the period March 1, 2003 to February 28, 2004 were reviewed and all intubations involving the use of drugs were included in the analysis. Measurements of oxygen saturation (SpO2) and systolic blood pressure (SBP) were obtained from the printed record produced by the portable monitor.

RESULTS

During the 12-month period 244 RSIs were performed. Completed SpO2 data were available on 175 patients (71.7%), and of those 32 (18.3%) experienced hypoxemia (SpO2 <90%, or >10% fall if initial SpO2 <90%). Completed SBP data were available for 192 patients (79.1%), and of those 25 (13%) experienced hypotension (SBP <90 mm Hg or >10 mm Hg fall if initial SBP <90 mm Hg). No patients developed both hypoxemia and hypotension.

CONCLUSIONS

Rates of hypoxemia and hypotension during prehospital RSI performed by London HEMS are relatively low. They are less than that found in previous studies of prehospital RSI and are similar to those reported in studies of in-hospital emergency RSI undertaken in the emergency department or ward setting. We therefore conclude that prehospital RSI has an acceptably low complication rate when performed by appropriately trained personnel.

Ensuring quality in prehospital airway management

PURPOSE OF REVIEW

Ensuring quality in prehospital airway management is challenging because the out-of-hospital setting is a fast-paced and unpredictable environment. The first step in meeting this challenge is the recognition by emergency medical service leaders that prehospital airway management is prone to error. Quality core values such as safety, effectiveness, timeliness, efficiency, and equity for prehospital airway management, specifically endotracheal intubation, will be discussed.

RECENT FINDINGS

Controlled studies in prehospital airway management are few. In those that have evaluated the use of endotracheal intubation in this setting, safety issues, increased scene time, and lack of effectiveness to improve outcome have been revealed.

SUMMARY

Emergency medical service administrators must critically evaluate the quality of prehospital airway management that they are providing to patients within their system by collecting the data necessary to identify quality issues and developing strategies to implement change. Research into other techniques that can provide ventilation and oxygenation to patients in the prehospital environment and that are safe and effective, such as laryngeal mask airway, need to be performed.

Prehospital rapid-sequence intubation of patients with trauma with a Glasgow Coma Score of 13 or 14 and the subsequent incidence of intracranial pathology

AIM

To identify the incidence of intracranial pathology in a population of patients with trauma with an on-scene Glasgow Coma Score (GCS) of 13 or 14, and the proportion that required prehospital intubation and ventilation.

METHOD

A retrospective review of a prehospital trauma database was carried out over a 12-month period, and 81 patients were reviewed. All had a traumatic mechanism of injury and had an on-scene GCS of 13 or 14 recorded by a prehospital doctor. 43 patients required prehospital rapid-sequence intubation. Overall, 31.5% of patients with a GCS of 13 or 14 had an abnormal computed tomography scan of the head and 20.5% had an intracranial haemorrhage.

RESULTS

For this group of patients with trauma with a drop of only one or two points on the GCS, the incidence of intracranial pathology was almost one in three and that of intracranial haemorrhage was one in five.

A comparison of rapid-sequence intubation and etomidate-only intubation in the prehospital air medical setting

OBJECTIVES

To compare laryngoscopy conditions produced by etomidate-only intubation (EOI) with those produced by rapid-sequence intubation (RSI) in the prehospital air medical setting.

METHODS

A prospective crossover trial design used two helicopters staffed by the same flight paramedics and nurses. Each aircraft used an EOI protocol (0.3 mg/kg) for six months. An RSI protocol using the same dose of etomidate plus succinylcholine (1.5 mg/kg) was used for the alternate six months. Laryngoscopy conditions were graded by three scales: 1) a formal Laryngoscopy Grading Scale (LGS), 2) the Percentage of Glottic Opening (POGO) score, and 3) subjective overall intubation difficulty using a Likert scale of 1 (very easy) to 5 (very difficult). Orotracheal intubation success was also recorded.

RESULTS

Forty-nine patients were intubated using the EOI (n = 24) and RSI (n = 25) protocols. Mean age was 38 years, 76% were male, and 90% were intubated for trauma. Fifteen (63%) of the 24 EOI patients required additional etomidate (n = 3) or RSI (n = 12) to allow intubation, while one (4%) of the 25 RSI patients required additional medication dosing (p < 0.0001). Laryngoscopy conditions were assessed for all patients. Good or acceptable conditions as assessed by the LGS were seen in 79% of RSI patients and 13% of EOI patients (p < 0.0001). Mean rates of POGO visualization were 60% with RSI and 12% with EOI (p < 0.0001). Mean global intubation difficulty scores were 3.0 (moderate) with RSI and 4.7 (difficult to very difficult) with EOI (p < 0.0001). Ninety-two percent of the patients undergoing RSI and 25% of the EOI patients were successfully orotracheally intubated (p < 0.0001).

CONCLUSIONS

Patients receiving RSI had better laryngoscopy conditions and were easier to intubate than patients receiving EOI. Intubation success rate was higher with RSI.

Pre-hospital endotracheal intubation and positive pressure ventilation is associated with hypotension and decreased survival in hypovolemic trauma patients: an analysis of the National Trauma Data Bank

BACKGROUND

Studies of pre-hospital endotracheal intubation (ETI) from single EMS systems have shown contradictory results, which may represent local differences in paramedic training and experience. An alternative hypothesis is that positive pressure ventilation increases mortality because positive pressure ventilation causes hypotension in severely injured hypovolemic patients.

METHODS

A national sample (National Trauma Data Bank, 1994-2002) was used to minimize effects of local paramedic training and experience. All patients with pre-hospital GCS < 8 (most likely to warrant early ETI) and ISS > 16 (most likely to be hypovolemic) were included. Patients intubated in the field (pre-hospital group, n = 871) and in the emergency department (ED group, n = 6581) were compared. To determine whether pre-hospital ETI was an independent predictor of hypotension and mortality, logistic regression was used to control for potential confounders, including age, ISS, body region injured, AIS scores, pre-hospital IV fluids, and other variables. Physiologic variables were not used, as they may be influenced by ETI and positive pressure ventilation, and were therefore considered outcomes, rather than predictors.

RESULTS

Groups were comparable in age, gender, anatomic distribution of injuries, likelihood of at least one severe injury (AIS >3) and other variables, except for head injury (ED 83%, pre-hospital 71%, p < 0.001) and ISS (ED 33 +/- 0.2, pre-hospital 36 +/- 0.6, p < 0.001). Patients intubated in the field were more likely to be hypotensive upon arrival in the ED (SBP < or = 90 mm Hg; ED 33%, pre-hospital 54%, p < 0.001), and had worse survival (ED 45% versus pre-hospital 24%, p < 0.001). Even after controlling for potential confounders, pre-hospital ETI was still an independent predictor of hypotension upon arrival in ED (OR 1.7, 95% CI 1.46 -2.09, p < 0.001) and decreased survival (OR 0.51, 95% C.I. 0.43-0.62, p < 0.001).

CONCLUSIONS

Pre-hospital endotracheal intubation in trauma patients is associated with hypotension and decreased survival. This may be mediated by the effect of positive pressure ventilation during hypovolemic states.

Air medical rapid sequence intubation: How can we achieve success?

Airway management is an essential component of the air medical transport of critically ill or injured patients. Many controversies surround the use of rapid sequence intubation (RSI) in the prehospital setting. The challenges of establishing an airway in this environment may exceed those in the hospital. However, it is clear that the same high standards for success demanded in the hospital must be applied to RSI in the prehospital setting for the practice to be accepted and result in positive outcomes. Given their volume of high acuity patients, air medical providers are ideal candidates for performing prehospital RSI. Undertaking this responsibility requires commitment to training and quality improvement. We present the components required to establish and maintain a successful air medical RSI program.

Predicting adverse outcomes in a diagnosis-based protocol system for rapid sequence intubation

Our ED at Louisiana State University developed a unique approach to airway management by having four diagnosis-based protocols for rapid sequence intubation (RSI). This study examines protocol use and outcome from RSI in an academic ED. The study objective was to identify variables that are predictive of adverse outcomes in patients requiring RSI. This was a 4-year prospective, observational, data-gathering study of all intubations in an academic ED setting with >250,000 patient visits per year. Four protocols were established for 1) children <10 years of age, 2) adults with increased intracranial pressure, 3) adults with chronic obstructive pulmonary disease/asthma, and 4) other adults not fitting B or C. A special continuing quality improvement (CQI) committee was established to examine each case of RSI. Prospective data were collected, including age, race, gender, protocol, diagnostic group, intubation indication, and preintubation oxygen saturation. Diagnostic group was categorized as medical, blunt trauma, or penetrating trauma. Adverse outcome was defined as any case with hemodynamic changes, those requiring surgical or bronchoscopic intervention, and those requiring more than three attempts at intubation. Data were analyzed using univariate analysis, logistic regression, and a binomial regression tree analysis with SPSS 9.0 (Chicago, IL) and Answer Tree (SPSS). A total of 1,320 consecutive intubated patients were included. Protocol A was used in 4%, B in 43%, C in 15%, and D in 38%. Significant differences in number of cases with adverse outcome were based on protocol (P =.03) and final diagnosis (P <.03). Protocol C was less likely to be associated with adverse outcome than protocol D (odds ratio [OR] = 0.2, 95% confidence interval [CI] = 0.1-0.7). Penetrating trauma was more likely to be associated with adverse outcome (OR = 1.8, 95%, CI = 1.1-3.2) than blunt trauma. A regression tree analysis yielded the following, all cases using protocol A or C or medical cases using B had an adverse event in 11 of 458 (2.4%), whereas nonmedical cases using protocols B or D and medical cases using D had adverse outcomes in 73 of 862 cases (8.5%). The decision rules lead to a better classification of cases with adverse outcomes (2.4 vs 8.5%, of = 6.1%, 95% CI = 3.7-8.4). Adult trauma patients who fit the protocols B or D or adult medical patients who fit protocol B were at higher risk for adverse outcomes with RSI. This could alert the physician to a population at higher risk for adverse outcomes. Variables available in a diagnosis-based protocol RSI system can be used to predict adverse outcome among patients requiring RSI.

Prehospital care of the patient with major trauma

Recent research efforts have demonstrated that many longstanding practices for the prehospital resuscitation of trauma patients may be inappropriate under certain circumstances. For example, traditional practices, such as application of anti-shock garments and i.v. fluid administration to raise blood pressure, may even be detrimental in certain patients with uncontrolled bleeding, particularly those with penetrating injuries. ETI, although potentially capable of transiently prolonging a patient's ability to tolerate circulatory arrest, may also be harmful if overzealous PPV further compromises cardiac output, particularly in those patients with severe hemodynamic instability. In addition, if these procedures delay patient transport, any benefit that they may offer could be outweighed by the delay in definitive care. Although traditionally taught to "hyperventilate" the patient with severe head injury, current recommendations are to avoid this tactic unless there is evidence of herniation. Even time-honored traditions, such as universal spinal precautions and CPR during circulatory arrest, are being scrutinized [2,134]. Further prospective randomized clinical trials are needed to better define the role of many overlapping therapies in prehospital trauma care. Such research must specifically address and stratify the different mechanisms of injury, anatomic areas involved, and the physiologic staging of the injury. Furthermore, the efficacy of a single intervention may be masked by a confounding variable [5]. For example, a trial of an effective new HBOC in moribund patients that indicates no advantage in the study results may have been confounded by overzealous PPV, which may have led to suboptimal outcomes. It is hoped that, in the future, EMS physicians will be able to not only better discriminate in their management of patients with major trauma but also improve outcomes as a result.

Prehospital and resuscitative airway care: should the gold standard be reassessed?

In the context of prehospital care and resuscitation, tracheal intubation has been regarded as the standard in airway treatment. The evidence for this status is rather weak. It does not take into account the level of training and experience of the personnel attempting intubation, and whether they use neuromuscular blockers. In unskilled hands, attempted tracheal intubation is harmful; unrecognized esophageal intubation is disastrous. When healthcare providers lack adequate skills in tracheal intubation, alternative airway devices, such as the laryngeal mask airway or the Combitube, may be better options than a simple facemask. Healthcare personnel using any of these devices should be adequately trained and maintain frequent practice.