Dr. Bledsoe: Do you feel there’s a role for RSI in the prehospital setting? Dr. Wayne, I know your program has decades of success with RSI. What do you think?

Dr. Wayne: Although there are no nationally defined indications for the use of RSI in the field, we at Whatcom Medic One believe that RSI is indicated for any patient in whom there’s a need to control an “uncontrolled” airway. This may include depressed GCS score, excess secretions, hypoxia that may be correctable, ventilatory fatigue or central nervous system depression with or without secondary respiratory depression.

Dr. Tan: I believe there is, but it must be in the right context with requisite oversight and extraordinary training. I oversee more than 100 paramedics in my system, yet only 10 of them have RSI privileges. They’re required to obtain critical care certification, attend ongoing training sessions with me every 12 weeks, attend annual specialized training courses and undergo 100% audits of their critical care trips. It’s a strenuous and time-consuming process but one that can’t be overemphasized given the complexity and danger inherent to RSI. I certainly don’t believe RSI should be a “routine” part of any standing orders, as there is nothing routine about it.

Dr. Wang: I think RSI should be restricted to the aeromedical setting for use by critical care flight nurses and/or flight medics for the reasons I’ve previously detailed. I really challenge those medical directors who currently allow RSI and promote its use in other systems. Although I applaud their efforts and attention to quality improvement and training, they still equate successful intubation with a positive outcome. As Dr. Eckstein said, in the absence of prospective RCTs, we can’t assume that prehospital RSI has actually improved outcomes for our patients.

Dr. Eckstein: RSI is potentially useful where paramedics have exceptional skill, training and medical oversight. Unfortunately, this is a tiny fraction of EMS agencies. If we replaced the “I” (intubation) with “A” (airway—Combitube, King, etc.), this might relieve much of the angst over prehospital RSI.

• Is there a risk for aspiration?
• Is the patient ventilating on their own?
• Is the patient oxygenating on their own?
• Is the patient conscious?
• How difficult will this ETI attempt be?
• What is my backup plan?

• Bag-valve mask (possibly with an OPA/NPA)
• Combi-tube
• King LT/LTD
• Laryngeal Mask Airway

Abstract
BACKGROUND: Initiated by a clinical case of critical endotracheal tube (ETT) obstruction, we aimed to determine factors that potentially contribute to the development of endotracheal tube obstruction by its inflated cuff. Prehospital climate and storage conditions were simulated. METHODS: Five different disposable ETTs (6.0, 7.0, and 8.0 mm inner diameter) were exposed to ambient outside temperature for 13 months. In addition, every second of these tubes was mechanically stressed by clamping its cuffed end between the covers of a metal emergency case for 10 min. Then, all tubes were heated up to normal body temperature, placed within the cock of a syringe, followed by stepwise inflation of their cuffs to pressures of 3 kPa and > or =12 kPa, respectively. The inner lumen of the ETT was checked with the naked eye for any obstruction caused by the external cuff pressure. RESULTS: Neither in tubes that were exposed to ambient temperature (range: -12 degrees C to +44 degrees C) nor in those that were also clamped, visible obstruction by inflated cuffs was detected at any of the two cuff pressure levels. CONCLUSIONS: We could not demonstrate a critical obstruction of an ETT by its inflated cuff, neither when the cuff was over-inflated to a pressure of 12 kPa or higher, nor in ETTs that had been exposed to unfavorable storage conditions and significant mechanical stress.

Abstract
STUDY OBJECTIVE: We evaluate changes in endotracheal tube intracuff pressures among intubated patients during aeromedical transport. We determine whether intracuff pressures exceed 30 cm H(2)O during aeromedical transport. METHODS: During a 12-month period, a helicopter-based rescue team prospectively recorded intracuff pressures of mechanically ventilated patients before takeoff and as soon as the maximum flight level was reached. With a commercially available pressure manometer, intracuff pressure was adjusted to /=30 cm H(2)O, 72% had intracuff pressures >/=50 cm H(2)O, and 20% even had intracuff pressures >/=80 cm H(2)O. CONCLUSION: Endotracheal cuff pressure during transport frequently exceeded 30 cm H(2)O during aeromedical transport. Hospital and out-of-hospital practitioners should measure and adjust endotracheal cuff pressures before and during flight. Copyright © 2010 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

BACKGROUND: The ability to perform drug calculations accurately is imperative to patient safety. Research into paramedics' drug calculation abilities was first published in 2000 and for nurses' abilities the research dates back to the late 1930s. Yet, there have been no studies investigating an undergraduate paramedic student's ability to perform drug or basic mathematical calculations. The objective of this study was to review the literature and determine the ability of undergraduate and qualified paramedics to perform drug calculations. METHODS: A search of the prehospital-related electronic databases was undertaken using the Ovid and EMBASE systems available through the Monash University Library. Databases searched included the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, JSTOR, EMBASE and Google Scholar, from their beginning until the end of August 2009. We reviewed references from articles retrieved. RESULTS: The electronic database search located 1,154 articles for review. Six additional articles were identified from reference lists of retrieved articles. Of these, 59 were considered relevant. After reviewing the 59 articles only three met the inclusion criteria. All articles noted some level of mathematical deficiencies amongst their subjects. CONCLUSIONS: This study identified only three articles. Results from these limited studies indicate a significant lack of mathematical proficiency amongst the paramedics sampled. A need exists to identify if undergraduate paramedic students are capable of performing the required drug calculations in a non-clinical setting.

Pubmed [2]

PURPOSE OF REVIEW: The primary purpose of this article is to highlight the latest airway research in multitrauma. RECENT FINDINGS: Management of the airway in multitrauma patients is a critical resuscitation task. Prehospital airway management is difficult with a high risk of failure, complications, or both. In-hospital performed conventional oral intubation with manual in-line stabilization, cricoid pressure, and a backup plan for a surgical airway is still the most efficient and effective approach for early airway control in multitrauma patients. Selective utilization of airway maintenance, instead of ultimate airway control in the field, has been suggested as a primary prehospital strategy. Properties of videolaryngoscopes complement standard laryngoscopes. When compared with a Macintosh laryngoscope, the Airtraq and Airwayscope diminish cervical spine motion during elective orotracheal intubation. Penetrating neck injuries are the most frequent indication for awake intubation, whereas patients with maxillofacial injuries have the highest rate of initial surgical airway. SUMMARY: Risks and benefits of ultimate prehospital airway control is a controversial topic. Utilization of videolaryngoscopes in multitrauma remains open for research. Standardization of training requirements, equipment, and development of prehospital and in-hospital airway algorithms are needed to improve outcomes. Rational utilization of available airway devices, development of new devices, or both may help to promote this goal.

Reduce patient prehospital delay in ACS.

Pubmed [3]

BACKGROUND: Delay from onset of acute coronary syndrome (ACS) symptoms to hospital admission continues to be prolonged. To date, community education campaigns on the topic have had disappointing results. Therefore, we conducted a clinical randomized trial to test whether an intervention tailored specifically for patients with ACS and delivered one-on-one would reduce prehospital delay time. METHODS AND RESULTS: Participants (n=3522) with documented coronary heart disease were randomized to experimental (n=1777) or control (n=1745) groups. Experimental patients received education and counseling about ACS symptoms and actions required. Patients had a mean age of 67+/-11 years, and 68% were male. Over the 2 years of follow-up, 565 patients (16.0%) were admitted to an emergency department with ACS symptoms a total of 842 times. Neither median prehospital delay time (experimental, 2.20 versus control, 2.25 hours) nor emergency medical system use (experimental, 63.6% versus control, 66.9%) was different between groups, although experimental patients were more likely than control to call the emergency medical system if the symptoms occurred within the first 6 months following the intervention (P=0.036). Experimental patients were significantly more likely to take aspirin after symptom onset than control patients (experimental, 22.3% versus control, 10.1%, P=0.02). The intervention did not result in an increase in emergency department use (experimental, 14.6% versus control, 17.5%). CONCLUSIONS: The education and counseling intervention did not lead to reduced prehospital delay or increased ambulance use. Reducing the time from onset of ACS symptoms to arrival at the hospital continues to be a significant public health challenge. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov. Identifier NCT00734760.

Termination of resuscitation protocols.

Termination of resuscitation by Shaggy

Pubmed [4]

BACKGROUND: Despite the existence of national American Heart Association guidelines and 2 termination-of-resuscitation (TOR) rules for ceasing efforts in refractory out-of-hospital cardiac arrest, many emergency medical services agencies in the United States have adopted their own local protocols. Public policies and local perceptions may serve as barriers or facilitators to implementing national TOR guidelines at the local level. METHODS AND RESULTS: Three focus groups, lasting 90 to 120 minutes, were conducted at the National Association of Emergency Medical Services Physicians meeting in January 2008. Snowball sampling was used to recruit participants. Two reviewers analyzed the data in an iterative process to identify recurrent and unifying themes. We identified 3 distinct groups whose current policies or perceptions may impede efforts to adopt national TOR guidelines: payers who incentivize transport; legislators who create state mandates for transport and allow only narrow use of do-not-resuscitate orders; and communities where cultural norms are perceived to impede termination of resuscitation. Our participants suggested that national organizations, such as the American Heart Association and American College of Emergency Physicians, may serve as potential facilitators in addressing these barriers by taking the lead in asking payers to change reimbursement structures; encouraging legislators to revise laws to reflect the best available medical evidence; and educating the public that rapid transport to the hospital cannot substitute for optimal provision of prehospital care. CONCLUSIONS: We have identified 3 influential groups who will need to work with national organizations to overcome current policies or prevailing perceptions that may impede implementing national TOR guidelines.

Prehospital 12-Lead reduces door-to-balloon times

Head over to the Prehospital 12 Lead Blog

Pubmed [5]

BACKGROUND: American College of Cardiology/American Heart Association guidelines recommend greater than 75% of patients with an ST-elevation myocardial infarction receive primary percutaneous coronary interventions (PPCI) within 90 minutes. Despite these recommendations, this goal has been difficult to achieve. METHODS AND RESULTS: We conducted a prospective interventional study involving 349 patients undergoing PPCI at a single tertiary referral institution to determine the impact of prehospital 12-lead ECG triage and emergency department activation of the infarct team on door-to-balloon time (D2BT). The median D2BT of all patients (n=107) who underwent PPCI after field ECG and emergency department activation of the infarct team (MonashHEART Acute Myocardial Infarction [MonAMI] group) was 56 minutes (interquartile range, 36.5 to 70) compared with the median time of a contemporary group (n=122) undergoing PPCI during the same period but not receiving field triage (non-MonAMI group) of 98 minutes (73 to 126.45). The median D2BT time of 120 consecutive patients who underwent PPCI before initiation of the project (pre-MonAMI group) was 101.5 minutes (72.5 to 134; P less than 0.001). The proportion of patients who achieved a D2BT of less than or = 90 minutes increased from 39% in the pre-MonAMI group and 45% in the non-MonAMI group to 93% in the MonAMI group (P less than 0.001). CONCLUSIONS: The performance of prehospital 12-lead ECG triage and emergency department activation of the infarct team significantly improves D2BT and results in a greater proportion of patients achieving guideline recommendations.

Monitoring mean arterial blood pressure.

Umm.. See the first abstract. Luckily most modern monitors calculate this for us.

Pubmed [6]

OBJECTIVES: For some time, the inaccuracies of non-invasive blood pressure measurement in critically ill patients have been recognised. Measurement difficulties can occur even in optimal conditions, but in prehospital transportation vehicles, problems are exacerbated. Intra-arterial pressures must be used as the reference against which to compare the performance of non-invasive methods in the critically ill patient population. Intra-arterial manometer data observed from the patient monitor has frequently been used as the reference against which to assess the accuracy of noninvasive devices in the emergency setting. To test this method's validity, this study aimed to determine whether numerical monitor pressures can be considered interchangeable with independently sampled intra-arterial pressures. METHODS: Intensive Care Unit nurses were asked to document arterial systolic, diastolic and mean pressures numerically displayed on the patient monitor. Observed pressures were compared to reference intra-arterial pressures independently recorded to a computer following analogue to digital conversion. Differences between observed and recorded pressures were evaluated using the Association for the Advancement of Medical Instrumentation (AAMI) protocol. Additionally, two-level linear mixed effects analyses and Bland-Altman comparisons were undertaken. RESULTS: Systolic, diastolic and integrated mean pressures observed during 60 data collection sessions (n = 600) fulfilled AAMI protocol criteria. Integrated mean pressures were the most robust. For these pressures, mean error (reference minus observed) was 0.5 mm Hg (SD 1.4 mm Hg); 95% CI (two-level linear mixed effects analysis) 0.4-0.6 mm Hg; P less than 0.001. Bland-Altman plots demonstrated tight 95% limits of agreement (-2.3 to 3.2 mm Hg), and uniform agreement across the range of mean blood pressures. CONCLUSIONS: Integrated mean arterial pressures observed from a well maintained patient monitor can be considered interchangeable with independently sampled intra-arterial pressures and may be confidently used as the reference against which to test the accuracy of non-invasive blood pressure measuring methods in the prehospital or emergency setting.

CORE PRINCIPLE

AIRWAY, VENTILATION, AND OXYGENATION

AIRWAY ADEQUACY

IMPORTANT CONCEPTS IN AIRWAY MANAGEMENT

The assessment and management of a patient’s airway is the crucial initial priority in all circumstances. Usually, this is easily accomplished when faced with a talking, breathing, and coherent patient. Other times it is more difficult to determine if the patient’s airway is compromised, ventilatory rate inadequate, or air exchange is poor. Additionally, there may be circumstances when airway adequacy may become rapidly compromised secondary to a disease or injury (i.e., thermal injury to the face or anaphylaxis). When these conditions exist, an airway management approach must be determined rapidly and early airway management must be considered a priority.

The purpose of establishing an adequate airway (or protecting an airway from compromise) is to allow appropriate movement of air to maintain oxygenation and to facilitate elimination of CO2. There is a significant risk of hypoventilation and hypoxia with any airway intervention. This risk is often overlooked in the “heat of the battle.” Sometimes, during the actual procedure, healthcare providers lose sight of the need for basic airway and ventilatory management. As procedural attempts continue, the patient’s oxygenation status drastically decreases and their CO2 dramatically rises. Both of these conditions are associated with significant potential to worsen patient outcome. The practice of pre-oxygenating a patient (creating an oxygen reseviour by nitrogen wash-out) before DAI is specifically to minimize the hypoxia associated with airway procedures.

Hypoxia has been shown to decrease survival from pre-hospital trauma, especially in head injury. Similarly, increases in CO2 as a result of little or no ventilation (for example, during the time an advanced airway is being attempted) also decreases survival and worsens outcome in head injury patients. If the process of establishing an airway is prolonged (as much as 30 seconds), we may actually make the patient’s outcome worse, even though the airway is established. If attempts at advanced airway placement are difficult or prolonged, an assessment of the adequacy of BLS airway management must be made. It is better to maintain a BLS airway than make repeated or prolonged attempts to establish an advanced airway. All Providers on scene should be aware of periods of no ventilation (during airway management, transport or other circumstances) and make an effort to correct the situation immediately. In patients that can be ventilated effectively with a BVM, advanced airway attempts should be limited to two (2) in the non-arrested patient. The decision to intubate a patient must ALWAYS be focused on the needs of the patient, availability of equipment, skill of the intubating Provider and possible use of more advanced tools or experienced Providers that are en route to successfully intubate with the fewest number of attempts possible. Repeated unsuccessful attempts to intubate a patient that can be effectively ventilated are harmful. The use or deference of a “Patients” second or third intubation attempt is not a question of pride or failed ability. It is the patient that potentially suffers. It is acceptable (and in many cases expected) for all responders to defer the 2nd or 3rd Intubation attempt to a more experienced Provider as we work as a team to secure the airway.

AIRWAY MANAGEMENT APPROACH

Our approach to airway management is extremely important. The best decision on how to manage an airway can be reached by answering the following questions:

• Is the airway being adequately maintained?

• Is there a need to clear the airway?

• Is the airway being protected against aspiration?

• Is ventilation adequate?

• Is oxygenation adequate?

• Is there a condition present, or is there a therapy required that mandates airway adjuncts?

• Do I have the tools to correct this problem?

• Do I have the skills to correct this problem?

Airway procedures should be implemented starting with the least and progressing to the most invasive:

• Manual maneuver (chin lift, jaw thrust, etc.),

• BLS adjuncts (NPA, OPA),

• Cardiac Arrest airway (King LTS-D),

• Orotracheal intubation,

• Rescue airway (LMA Supreme, King LTS-D),

• Surgical / needle cricothyrotomy

If the patient’s airway cannot be maintained (i.e., inadequate ventilation), the Provider should immediately consider airway maneuvers (within their scope of practice) as listed above. If unable to establish an advanced airway, return to BLS maneuvers while evaluating the need for a rescue airway. If still unable to maintain adequate ventilation and/or airway protection, proceed to placement of the LMA, King LTS-D or other rescue airway. If STILL unable to ventilate, and the patient would be unlikely to survive, proceed to needle cricothyrotomy for the pediatric patient (10 years of age or less) or surgical cricothyrotomy (over 10 years old).

COMMON SENSE APPROACH TO FACILITATE DIFFICULT AIRWAY MANAGEMENT

• Audibly verbalize the procedure as it is being done (by intubating provider)

• Airway Axis Alignment by head repositioning (occipital / shoulder padding, “ramping”, sniffing)

• Consider laryngeal manipulation,

• Change your position,

• Change the blade,

• Change the provider who is intubating (this is often overlooked as a significantly useful approach)

• Re-evaluate the need for an advanced airway versus expedited transport of patient to definitive care

with BLS airway management

• Once the airway is established, secure it with tube holder

CONFIRMING AND MONITORING APPROPRIATE ADVANCED AIRWAY PLACEMENT

Once an advanced airway is placed, it is crucial that all efforts are made to ensure it is definitively placed. All advanced airway placements must be confirmed by ETCO2 capnography. Additionally, it is important to continuously monitor airway placement for changes related to movement or obstruction. It is essential that all advanced airway attempts, as well as confirmation of placement, be documented in the Patient Care Record (PCR) with copies of all monitoring equipment printouts (O2 saturation and ETCO2) when available.

Confirmation of an appropriately placed advanced airway is multi-faceted and should include:

• Visualizing the placement,

• Auscultating for breath sounds over both lungs and epigastrium,

• Observing for equal chest rise and fall,

• Monitoring ETCO2 (capnography),

• Monitoring pulse oximetry,

• Monitoring changes in vital signs, especially skin color

Once an advanced airway has been established, management of the tube or catheter should be of the

highest priority during any patient movement.

• An appropriately sized cervical collar should be applied immediately following successful placement

and securing of the airway.

• If patient is to be transported, they should be placed on a backboard and secured.

􀂃 The only exception would be patients who cannot tolerate a supine position (i.e. awake

patient in respiratory distress, patient with pulmonary edema, etc.)

• The BVM is to be disconnected from the tube during any transitional movement including

􀂃 Log-rolling patient onto a backboard

􀂃 Moving patient onto a stretcher

􀂃 Loading and unloading from ambulance or helicopter

􀂃 Transfer to the hospital stretcher

􀂃 The tube is to be reassessed following any patient movement

Appropriate demonstration of persistent ETCO2 is the most reliable indicator of tube placement in our assessment toolbox. All advanced airway placement must be confirmed by ETCO2 capnography. Additionally, it is important to continuously monitor tube placement for any changes related to movement or obstruction. Loss of ETCO2 is an immediate indicator of significant change, whether it is loss of tube placement or loss of perfusion. ALL changes in ETCO2 must be immediately evaluated to determine the reason for change.

VENTILATION / OXYGENATION – ADEQUATE / APPROPRIATE

INTRODUCTION

After it has been confirmed that the patient has a patent airway, the next step is to assess ventilation and oxygenation status. An initial assessment of respiratory rate and depth, skin color, and mental status will give a quick picture of whether the patient is breathing and oxygenating adequately. Your physical assessment, ETCO2 monitoring, and pulse oximetry provide a very accurate picture of how well the patient is being ventilated and oxygenated. It is crucial that all Providers take responsibility for assessing adequate oxygenation and ventilation in every patient.

This can be accomplished by monitoring:

• Respiratory rate and depth,

• Skin color,

• Capillary refill,

• Lung sounds,

• Work of breathing,

• Patient position (i.e. Tripod),

• Ability (inability) to maintain secretions,

• Pulse oximetry and ETCO2 monitoring

OXYGENATION AND VENTILATION – THE IMPORTANT RELATIONSHIP

Ventilation is the mechanical aspect of breathing, in which O2 moves into the lungs and CO2 (normal byproduct of metabolism) moves out of the lungs. Proper ventilation requires both adequate tidal volume (500-600 cc for an adult male) and respiratory rate. Oxygenation is defined as “the addition of oxygen to any system, including the human body. ”With ventilation serving as the mechanical means of adding oxygen to the body, the patient must have sufficient oxygen available, and the ability for that oxygen to be utilized (O2/CO2 exchange). While ventilatory rate and depth are the key components, there are other factors that can affect whether or not the patient is being adequately oxygenated. Even if ventilation rate and depth are adequate, every patient must be evaluated for the need to have supplemental oxygen delivered and the most appropriate means for that to occur.

Considerations in determining a patient’s need for supplemental oxygen include:

• Level of consciousness

• Ventilation rate and depth

• Mental status

• Circulatory status

• Skin color

• Chief complaint

• Previous history

• Type of incident

A condition related to a patient’s breathing depth and rate that can create uncertainty for Providers is hyperventilation. Because the patient is breathing at an excessive rate and/or depth, he/she expels too much CO2. The lack of adequate CO2 causes a drop in the acid levels of arterial blood resulting in a condition called alkalosis. (Simply, the buildup of excess base in the body’s fluids) It is the alkalosis that causes many of the symptoms commonly associated with hyperventilation including anxiety, dizziness, numbness, tingling in the hands, feet, and lips, and a sense of difficulty breathing. Hyperventilation can occur as a response to serious illness or, in a healthy person, as a response to psychological stress. In either case, the key is thorough assessment to identify treatable conditions. All patients suffering from hyperventilation should be given supplemental oxygen, calm reassurance in a professional manner in an effort to normalize their respiratory rate and depth, and be offered transport to the hospital. When inadequate oxygenation is recognized, it is essential that steps be taken to immediately supplement the patient’s oxygen intake.

Remember our primary treatment goals for patients suffering from inadequate oxygenation include:

• Preventing or correcting hypoxia

• Normalizing CO2

• Minimizing the effects of secondary injuries

• Decreasing airway resistance

Once it is determined that supplemental oxygen is required, the question would be “how much?” A truly correct answer can only be reached by thoroughly evaluating your patient’s condition and considering the following guidelines:

• Nasal cannula at 2-6 L/min for patients suffering from minor injury or illnesses where lower liter flow

is appropriate.

• Non-rebreather at 10-15 L/min (enough to keep reservoir filled) for patients presenting with altered

mental status, obvious difficulty breathing, poor skin color, poor circulatory status, possible or

confirmed CO Poisoning, etc.

• Bag-valve-mask at 15 L/min or greater (enough to keep reservoir filled) for patients with inadequate

ventilation rate and/or depth

VENTILATION RATE AND DEPTH

A common pitfall in ventilation is to over-ventilate the patient by providing too much volume or too fast a rate.

The physics that allow us to move air in and out of the lungs can also have a major impact on blood circulation (one more important inter-relationship between the ABCs). When a normally breathing patient takes in a breath, intrathoracic pressure decreases, allowing air to be “sucked in” due to the resulting pressure differential. This is in contrast to patients that are ventilated with positive pressure (whether intubated, Bag-Valve-Mask or Mouth-to-Mask). In these patients, we INCREASE intrathoracic pressure as we inflate the lungs. In this case, the heart itself is “squeezed” and doesn’t fill as well or move blood forward as well. Overly aggressive ventilation will have a dramatically adverse effect on circulation. If we don’t pay attention to rate and depth, we may actually harm the patient’s circulation, drop their blood pressure, and decrease perfusion. Ventilation depth and rate is variable and driven by the patient’s condition. We must be mindful of the volume and rate at which we are ventilating the patient. The majority of adult patients should be ventilated at a rate of 12 breaths per minute (see below). Studies have shown that excessive ventilation rates significantly decreased coronary perfusion pressures and ultimately patient survivability. This is particularly true in cases of cardiac arrest. Each ventilation should be sufficient to create adequate chest rise and be delivered over one second. In the absence of ETCO2 and pulse oximetry, rescue breathing (patients with a pulse) should be performed at the following rates

Age Group Ventilatory Rate

Neonates 40-60 bpm

Infants and Children 12-20 bpm

Adults 10-12 pbm