Trauma | Paramedicine 101

Trauma Triad of Death

11/03/2010 by Adam Thompson, EMT-P 2 Comments

I was recently asked why we work so hard to keep trauma patients warm.

My answer is The Trauma Triad of Death.

From Wikipedia:

The Trauma triad of death is a medical term describing the combination of hypothermia, acidosis and coagulopathy. This combination is commonly seen in patients who have sustained severe traumatic injuries and results in a significant rise in the mortality rate (see Lewis (2000)).

The three conditions share a complex relationship; each factor can compound the others, resulting in high mortality if the cycle continues uninterrupted.

Severe hemorrhage in trauma diminishes oxygen delivery, causing the patient’s body temperature to drop (hypothermia). This in turn can halt the coagulation cascade, preventing blood from clotting (coagulopathy).

In the absence of blood-bound oxygen and nutrients (hypoperfusion), the body’s cells burn glucose for energy (lactic acidosis), which in turn increases the blood’s acidity (metabolic acidosis). Such an increase in acidity can reduce the efficiency of the heart muscles (myocardial performance), further reducing the oxygen delivery and hence triggering a deadly cycle.

Filed Under: Education, Trauma

Research: Management of the Airway in the Trauma Patient

08/13/2010 by Adam Thompson, EMT-P 1 Comment

Check this out…

J Trauma. 2010 Aug;69(2):294-301. [Pubmed]
Prehospital airway and ventilation management: a trauma score and injury severity score-based analysis.
Davis DP, Peay J, Sise MJ, Kennedy F, Simon F, Tominaga G, Steele J, Coimbra R.

Abstract

BACKGROUND:: Emergent endotracheal intubation (ETI) is considered the standard of care for patients with severe traumatic brain injury (TBI). However, recent evidence suggests that the procedure may be associated with increased mortality, possibly reflecting inadequate training, suboptimal patient selection, or inappropriate ventilation. OBJECTIVE:: To explore prehospital ETI in patients with severe TBI using a novel application of Trauma Score and Injury Severity Score methodology. METHODS:: Patients with moderate-to-severe TBI (head Abbreviated Injury Scale score 3+) were identified from our county trauma registry. Demographic information, pre-resuscitation vital signs, and injury severity scores were used to calculate a probability of survival for each patient. The relationship between outcome and prehospital ETI, provider type (air vs. ground), and ventilation status were explored using observed survival-predicted survival and the ratio of unexpected survivors/deaths. RESULTS:: A total of 11,000 patients were identified with complete data for this analysis. Observed and predicted survivals were similar for both intubated and nonintubated patients. The ratio of unexpected survivors/deaths increased and observed survival exceeded predicted survival for intubated patients with lower predicted survival values. Both intubated and nonintubated patients transported by air medical crews had better outcomes than those transported by ground. Both hypo- and hypercapnia were associated with worse outcomes in intubated but not in nonintubated patients. CONCLUSIONS:: Prehospital intubation seems to improve outcomes in more critically injured TBI patients. Air medical outcomes are better than predicted for both intubated and nonintubated TBI patients. Iatrogenic hyper- and hypoventilations are associated with worse outcomes.

This publication is prestigious enough to trust the validity of the study. It looks as if enough patients were ruled-in to take consideration of the evidence. With the increase in ICP (intracranial pressure) that intubation causes, it has been theorized in the past, that intubating the TBI patient only made them worse. However, this study shines a different light. So what do you think? The discussion is open.

Filed Under: Aeromedical, Airway, Airway Management, Intubation, Research, Trauma

Prehospital Research

01/06/2010 by Adam Thompson, EMT-P 4 Comments

Every once in a while I will head over to Pubmed.com and run a quick search on prehospital. It is a good way to stay current in this ever-changing field. It is also good practice to stay relevant when advocating evidence-based medicine. Here are some abstracts from my most recent query. All are open for discussion, so please leave your comments.

Can medics do math?

Drug Math Tutorial

Pubmed [1]

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.

Intubation in trauma patients.

Rogue Medic’s Airway Post (one of many)

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.

Filed Under: Airway, Cardiac Arrest, Education, Research, Trauma

Prehospital Spinal Clearance Part III

06/07/2009 by Adam Thompson, EMT-P 2 Comments

The evidence is here…

You have heard me mention the NEXUS study a few times, and in this post I am going to finally explain exactly what it is and ask if its the solution.

NEXUS stands for National Emergency X-Radiography Utilization Study. This study has been used in a few different aspects of emergency medicine, but has definitely shown its worth in the prehospital environment. [1]

Fear of failure to identify cervical spine injury has led to extremely liberal use of radiography in patients with blunt trauma and remotely possible neck injury. A number of previous retrospective and small prospective studies have tried to address the question of whether any clinical criteria can identify patients, from among this group, at sufficiently low risk that cervical spine radiography is unnecessary. The National Emergency X-Radiography Utilization Study (NEXUS) is a very large, federally supported, multicenter, prospective study designed to define the sensitivity, for detecting significant cervical spine injury, of criteria previously shown to have high negative predictive value. Done at 23 different emergency departments across the United States and projected to enroll more than 20 times as many patients with cervical spine injury than any previous study, NEXUS should be able to answer definitively questions about the validity and reliability of clinical criteria used as a preliminary screen for cervical spine injury.

The following image is of a flowchart that utilizes the NEXUS guidelines to determine whether or not to implicate spinal immobilization. It is almost identical to the one found in my Prehospital Trauma Life Support (PHTLS) book.

I know its hard to read, you can use the instructions on the right side of this page for larger viewing.

This criteria has come from the results of the study and has shown to be successfully implemented in the protocols of a few EMS agencies nationwide. The criterion is very similar to the NEXUS criteria for x-ray in the emergency department. Even though the criteria was initially intended to rule out the need for an x-ray for spinal clearance, it is being used to rule out the need for spinal immobilization. The following is the intended use of the NEXUS criteria.

According to the NEXUS Low-Risk Criteria, cervical spine radiography is indicated for trauma patients unless they exhibit ALL of the following criteria:

1. No posterior midline cervical spine tenderness
and
2. No evidence of intoxication
and
3. Normal level of alertness
and
4. No focal neurological deficit
and
5. No painful distracting injuries

Explanations:
These are for purposes of clarity only. There are not precise
definitions for the individual NEXUS Criteria, which are subject
to interpretation by individual physicians.

Midline posterior bony cervical spine tenderness is present if the patient complains of pain on palpation of the posterior midline neck from the nuchal ridge to the prominence of the first thoracic vertebra, or if the patient evinces pain with direct palpation of any cervical spinous process.

Patients should be considered intoxicated if they have either of the following: a) a recent history by the patient or an observer of intoxication or intoxicating ingestion; or b) evidence of intoxication on physical examination such as odor of alcohol, slurred speech, ataxia, dysmetria or other cerebellar findings, or any behavior consistent with intoxication. Patients may also be considered to be intoxicated if tests of bodily secretions are positive for drugs (including but not limited to alcohol) that affect level of alertness.

An altered level of alertness can include any of the following: a) Glasgow Coma Scale score of 14 or less; b) disorientation to person, place, time, or events; c) inability to remember 3 objects at 5 minutes; d) delayed or inappropriate response to external stimuli; or, e) other.

Any focal neurologic complaint (by history) or finding (on motor or sensory
examination).

No precise definition for distracting painful injury is possible. This includes any condition thought by the clinician to be producing pain sufficient to distract the patient from a second (neck) injury. Examples may include, but are not limited to: a) any long bone fracture; b) a visceral injury requiring surgical consultation; c) a large laceration, degloving injury, or crush injury; d) large burns: or e) any other injury producing acute functional impairment. Physicians may also classify any injury as distracting if it is thought to have the potential to impair the patient’s ability to appreciate other injuries.

See how this can easily be converted in to a prehospital guideline? Of coarse you can, I already showed it to you.

It only makes sense that the same criteria that physicians use in their assessment to clear a cervical spine be used by EMTs/paramedics. If it can be taught to a doctor, why not us? We have all seen physicians take the cervical collars, that we have applied, off the patients that we bring in. This criteria has been questioned and compared to other studies such as the Canadian method, and I will go over a retrospective comparison of these two methods in my next post on this topic.

Click here for the Michigan protocol that I mentioned in my last post on this topic. Even though they implement some of the same assessments as NEXUS, they do not cite them as a reference. Their protocol includes a rule in method. If any of the specified findings are present, they are to immobilize.

Click here for the 2002 version of Maine’s spinal clearance protocol. They appear to have included all of the NEXUS criteria and then some. They claim to have an increased sensitivity of spinal assessment:

An additional Maine EMS 2002 Spine Assessment Protocol departure from the NEXUS investigation is the direction to immobilize patients for a complaint of neck pain as well as any tenderness present in the prehospital spine assessment. This change is purposefully meant to provide an added level of concern for spine injury by increasing the “sensitivity” of the spine assessment protocol. This direction should also serve as a means for decreasing the disagreement potential between providers’ (both in and out of the hospital) assessment of individual patients.

While the NEXUS investigation applies solely to the cervical spine, large scale clinical trials evaluating clinical decision rules for thoracic, lumbar, or sacral spine injuries have yet to be performed. As a consequence, care of the entire spine generally follows cervical spine assessment and treatment principles.

The prehospital assessment of tenderness should include, but not be limited to, the palpation of the posterior midline spine. While NEXUS has emphasized the sole importance of posterior, midline spine tenderness in cervical spine assessment, the Maine EMS 2002 Spine Assessment Protocol includes consideration of any areas of spine tenderness as a means for immobilization. This decision represents another adaptation of the NEXUS rules in an attempt to improve the instrument’s sensitivity for any spine injury as well as decreasing medical provider disagreement potential.

Finally, we have found research that was done on a large enough scale to be considered conclusive evidence to support a prehospital cervical spine clearance protocol. In fact, it is currently being used by many prehospital clinicians already. So why isn’t it universally accepted?

As I stated, in the next post on this topic I will go over the comparison between NEXUS and the Canadian method. Maybe we haven’t reached the final answer.

[1]Hoffman JR, Wolfson AB, Todd K, Mower WR: Selective cervical spine radiography in blunt trauma: methodology of the National Emergency X-Radiography Utilization Study (NEXUS). Annals of Emergency Medicine 2001.

Filed Under: Research, Trauma

Prehospital Spinal Clearance Part II

06/04/2009 by Adam Thompson, EMT-P 3 Comments

A closer look at the research…

With the start of this topic, I thought I would get by with some easy research and criticisms. As I dove into this subject I soon realized it wasn’t going to be that easy. In part one, I explained what struck the question and I began to look further into statements made by Trauma.org. The replies to my first post have given me new ideas and directions. The research is all there for me, and there isn’t a need to reinvent the wheel here. There is a need however to ask some good questions and get the unbiased answers. In my next couple of posts on this subject I will try to take a look at the timeline of research and with skepticism I will provide you with the evidence I find. With the evidence out there, I don’t see a reason we don’t have a universally accepted guideline for clinically clearing the cervical spine in the prehospital environment. Liability is unfortunately the most-likely answer to a question like this one–not science.

The 1999 study mentioned in part one listed Michigan and Maine as cohorts that implemented the criteria they studied for the use of spinal immobilization depending on mechanism of injury. After a couple go-arounds with Google, I found the 2005 edition of the Spinal Injury Assessment and Immobilization guideline of the Southeast Michigan Regional Protocol. I was able to find Maine’s 2002 protocol, post NEXUS, and found it very interesting. I am going to get into those in a further post to stay chronological.

I want to take a look at some literature I found from the AANS & CNS that was done just after the turn of the new century. This was done prior to the NEXUS study (I will get into this study later) so NEXUS didn’t make the 101 reference list. That’s right, there is really 101 references, consisting of research from 1966 to 2001.

Right from the get-go[1]:

Standards: There is insufficient evidence to support treatment standards.
Guidelines: There is insufficient evidence to support treatment guidelines.

In the 101 references they listed, they couldn’t find enough evidence to support treatment standards or guidelines. Almost 40 years of research, no sufficient evidence–amazing! Give me time and I will go through their references, but for now lets take a further look at what this paper has to say.

Options:

It is suggested that all trauma patients with a cervical spinal column injury or with a mechanism of injury having the potential to cause cervical spinal injury should be immobilized at the scene and during transport using one of several available methods.

A combination of a rigid cervical collar and supportive blocks on a backboard with straps is very effective in limiting motion of the cervical spine and is recommended. The longstanding practice of attempted cervical spinal immobilization using sandbags and tape alone is not recommended.

They have insufficient evidence to support treatment or guidelines, but they promote a treatment that they have guide-lined. I am being critical of the literature so far, but this next statement gives me good reason:

The chief concern during the initial management of patients with potential cervical spinal injuries is that neurologic function may be impaired due to pathologic motion of the injured vertebrae. It is estimated that 3% to 25% of spinal cord injuries occur after the initial traumatic insult, either during transit or early in the course of management.

Okay, I agree that we should be concerned with causing further harm or injury to our patients. Where do they get their estimate from regarding post-incident spinal cord injuries? They list 6 of there citations after that statement. 3% to 25% is a big margin, and to think that a quarter of all spinal cord injuries could be caused by first responders is scary. It may not be impossible, but I feel this is very unlikely. They then state that multiple cases have been reported where mishandling of the cervical spine lead to injury; they list 4 of there references after that one.

In the same paragraph the paper attributes neurological improvement of the spinal cord injured patients over the last 30 years to EMS. This conclusion was made after they state that in the 1970′s, 55% of spinal cord injuries presented with complete lesions and in the 1980′s, 61% had incomplete lesions. This is pretty interesting as well, and might lead to one of the answers to a seemingly easy question.

Where is the proof that spinal immobilization even works?

-Rogue Medic

It would be extremely difficult to show that without the implementation of full spinal immobilization a patient would suffer further injury. It is enlightening to read that there has been noticeable improvement since the implementation of prehospital spinal precautions. In further parts of this discussion I will revisit this question because it is a good one and deserves more than a one paragraph answer.

Back to the study in question:

Recently, the use of spinal immobilization for all trauma patients, particularly those with a low likelihood of traumatic cervical spinal injury has been questioned. It is unlikely that all patients rescued from the scene of an accident or site of traumatic injury require spinal immobilization.

They follow this up footnoting four of their citations and a statement regarding a triage-based criteria to determine appropriateness of immobilization. This is exactly what we are looking for. I wish they would have elaborated more in this paper though. Here is an abstract from one of the listed references[2]:

OBJECTIVE: To examine the effect of emergency immobilization on neurologic outcome of patients who have blunt traumatic spinal injuries. METHODS: A 5-year retrospective chart review was carried out at 2 university hospitals. All patients with acute blunt traumatic spinal or spinal cord injuries transported directly from the injury site to the hospital were entered. None of the 120 patients seen at the University of Malaya had spinal immobilization during transport, whereas all 334 patients seen at the University of New Mexico did. The 2 hospitals were comparable in physician training and clinical resources. Neurologic injuries were assigned to 2 categories, disabling or not disabling, by 2 physicians acting independently and blinded to the hospital of origin. Data were analyzed using multivariate logistic regression, with hospital location, patient age, gender, anatomic level of injury, and injury mechanism serving as explanatory variables. RESULTS: There was less neurologic disability in the unimmobilized Malaysian patients (OR 2.03; 95% CI 1.03-3.99; p = 0.04). This corresponds to a less than 2% chance that immobilization has any beneficial effect. Results were similar when the analysis was limited to patients with cervical injuries (OR 1.52; 95% CI 0.64-3.62; p = 0.34). CONCLUSION: Out-of-hospital immobilization has little or no effect on neurologic outcome in patients with blunt spinal injuries.

I’m not going to lie, the first thing I always read in these abstracts is the conclusion. Read the conclusion to this one. Doesn’t that statement contradict a couple points we just mentioned. How this same paper attributes neurological improvement to EMS, and how immobilization is a vital part of the treatment rendered by EMS. Looks like we revisited Rogue Medic’s question earlier than expected. Before we do, I want to look at a few more of this paper’s references to see what we can find[3].

OBJECTIVE: To determine whether EMS providers can accurately apply the clinical criteria for clearing cervical spines in trauma patients. METHODS: EMS providers completed a data form based on their initial assessments of all adult trauma patients for whom the mechanism of injury indicated immobilization. Data collected included the presence or absence of: neck pain/tenderness; altered mental status; history of loss of consciousness; drug/alcohol use; neurologic deficit; and other painful/distracting injury. After transport to the ED, emergency physicians (EPs) completed an identical data form based on their assessments. Immobilization was considered to be indicated if any one of the six criteria was present. The EPs and EMS providers were blinded to each other’s assessments. Agreement between the EP and EMS assessments was analyzed using the kappa statistic. RESULTS: Five-hundred seventy-three patients were included in the study. The EP and EMS assessments matched in 78.7% (n = 451) of the cases. There were 44 (7.7%) patients for whom EP assessment indicated immobilization, but the EMS assessment did not. The kappa for the individual components of the assessments ranged from 0.35 to 0.81, with the kappa for the decision to immobilize being 0.48. The EMS providers’ assessments were generally more conservative than the EPs’. CONCLUSION: EMS and EP assessments to rule out cervical spinal injury have moderate to substantial agreement. However, the authors recommend that systems allowing EMS providers to decide whether to immobilize patients should follow those patients closely to ensure appropriate care and to provide immediate feedback to the EMS providers.

Interestingly enough, this study contradicts statements made in a study in my first post on this subject. The research in the other study concluded that emergency physicians and EMTs disagreed on the matter of cervical spine immobilization. This is a moot point by now because it doesn’t prove or disprove anything. Whether EMTs and physicians agree or not does not reflect the efficacy of a prehospital spinal clearance protocol. This next abstract is promising[4]:

OBJECTIVE: To determine whether paramedics can safely use a spinal clearance algorithm to reduce unnecessary spinal immobilization (SI) in the out-of-hospital setting. METHODS: Paramedics were instructed in the use of a spinal clearance algorithm that prompted assessment of the trauma patient’s 1) level of consciousness, 2) drug and/or alcohol use, 3) loss of consciousness during the event, 4) presence of spinal pain/tenderness, 5) presence of neurologic deficit, 6) concomitant serious injury, or 7) presence of pain with range of motion. The algorithm indicated that if any of the above were present, the patient should receive full SI, and if all of the above were negative, then SI could be withheld. Paramedics completed a tracking form that included the above and followed the patient to the emergency department (ED). Data were then gathered to determine the presence of spinal fracture, neurologic deficit, or a combination of the two. To compare the trends for SI, a retrospective medical incident report (MIR) review was conducted from the previous year. MIRs were selected based on the same criteria as those used for study inclusion. RESULTS: Two hundred eighty-one patients were included in the study, with 65% (n = 183) of them receiving SI. Two hundred ninety-three MIRs were included in the retrospective sample, with SI being provided 95% (n = 288) of the time. Comparison of these samples shows a 33% reduction in utilization of SI (95% confidence interval: 27.2%- 38.8%). CONCLUSION: An out-of-hospital spinal clearance algorithm administered by paramedics can reduce SI by one-third. Any application of a spinal clearance algorithm should be accompanied by rigorous medical supervision.

I’m sorry if this is turning into a post full of abstracts but this one in-particular is the first one I have read that was conducted before the year 2000 and shows positive results using a prehospital spinal clearance algorithm. This evidence was available prior to the statements made in that Trauma.org article, and could have been cited. I am going to stop criticizing Trauma.org for the rest of this discussion because I think I have proved my point. However, we have gone beyond that and into a greater discussion.

So far, what I have…

Prior to 2002 there has been much scrutiny in regards to the prehospital clearance of the cervical spine. There has been bold statements made by prestigious organizations to emphasize this point. There has been plenty of research on the topic, and as always, it is very contradictory. The question on why to immobilize patients in the first place has been touched on, but we haven’t completely answered it yet. We also have some evidence that EMTs are capable of agreeing with emergency physicians on this subject–go figure. I have about 200 more references to sift through, and hopefully I can create a pretty elaborate timeline to show you where we have been and where we are. I have yet to share the conclusive evidence on this matter, but it is coming! Hopefully this will be developed into a universally accepted guideline, since it is somewhat accepted already by many prehospital agencies. I am also going to share some of the protocols from these agencies and hopefully some post-implemented research.

I’m going to take a pause with this literature for now and I will be revisiting it in the near future because some of the other subtopics in this discussion are brought up in this paper. In the next part I am going to take a look at the infamous NEXUS study and PHTLS recommendations. To take part in a current discussion on this post please visit EMTcity.com. I list that forum a lot just because it is the one I actually enjoy posting on. Also, please provide your commentary right here if you have any. I use your comments when authoring these posts.

Works cited

[1]American Association of Neurological Surgeons and the Congress of Neurological Surgeons. “Pre-hospital cervical spinal immobilization following trauma. Sept 2001 The PDF

[2]Hauswald M, Ong G, et al: Out-of-hospital spinal immobilization: Its effect on neurologic injury (comments). Academic Emerg Med 5:214-219,1998.

[3]Brown LH, Gough JE, et al: Can EMS providers adequately assess trauma patients for

cervical spinal injury? Pre-Hospital Emergency Care 2:33-36,1989. Pubmed abstract

[4]Muhr MD, Seabrook DL, et al: Paramedic use of a spinal injury clearance algorithm
reduces spinal immobilization in the out-of-hospital setting. Pre-Hospital Emergency Care
3:1-6,1999.

Filed Under: Research, Trauma

Prehospital Spinal Clearance Part I

05/31/2009 by Adam Thompson, EMT-P 17 Comments

An evidence-based approach…

It’s no secret that I am a diehard advocate of progressive prehospital medicine. I am also a proponent of evidence-based medicine. Sometimes these two views can be conflicting because of the lack of evidence to back new medicine. I have often changed my views on certain treatments in light of new research. The outstanding presence of bias and valid arguments associated with medicine drives me to keep reading on, even after discovering what may seem like a correct answer. Looking in one place will never be an adequate solution to a complicated topic, at least this is true when it comes to medicine.

Here in my EMS system we practice evidence-based medicine. We also like to consider ourselves a pretty progressive organization. Our medical director gives us a lot of leeway, and holds us to a pretty high standard. You could see five different medics treat the same patient five different ways here in our system, and they will all have valid arguments for each treatment.

When it comes to a traumatic injury, backboards and neck collars are used at the discretion of the lead paramedic. I have seen paramedics that immobilize every patient they encounter that was involved in a car accident or any other blunt force traumatic event. I think this might be what we call CYA (cover your ass) procedures. These medics might have seen a missed spinal injury be improperly treated in their career, and an unfortunate victim of that care acquire a lifelong need for a wheelchair.

I have developed my own systematic approach to these trauma patients. Of coarse manual cervical spine immobilization is applied upon initial contact. If the patient is under the influence of alcohol, he/she gets the full package, board and collar. I have just had too many drunks that haven’t felt a stab wound or broken arm, let-alone a possible spine injury. This is also a strong consideration with anyone who has recently taken analgesics or elicit drugs. If they aren’t under the influence of drugs or alcohol I give an appropriate physical exam. I consider the mechanism of injury and touch the patient to assess for tenderness. If the patient is pain free, able to move all extremities, and rotate their head without pain or involuntary movement, they get to stay off the board. This isn’t evidence-based and I have begun to question my own rational.

Luckily, I haven’t had this go wrong. I pride myself in my assessment skills and appreciate the patient’s comfort level. A backboard is a very uncomfortable bed cushion for someone who doesn’t need it. Quite often, if they didn’t have pain to begin with, they will after being on a backboard for only a few minutes. Of coarse, muscle pains from being on a hard board is nothing in comparison to chronic paralysis from being mishandled; I can also appreciate this fact.

Recently I read a statement on Trauma.org that has sparked yet another need for further information gathering[1]:

There is no conclusive evidence in the literature that supports clinical clearance of the spine in the prehospital environment. There is enough variation between prehospital and in-hospital assessments to recommend that prehospital removal of spinal immobilisation be avoided.

This is a pretty blunt statement; no conclusive evidence, not any? What is Trauma.org’s definition of conclusive, I wonder. I know there must be something out there that supports the paramedic’s ability to adequately assess their patient and make a decision like this. I also wonder if the statement is made only in regards to removal of previously applied spinal immobilization. What kind then, manual immobilization or the whole package? Or is this statement in regards to all blunt trauma patients; should we immobilize them all? Maybe they are referring to only neck and/or back pain patients. The list of questions has quickly become a long one, luckily the authors listed their sources.

The first source listed is from a journal that I personally subscribe to, Prehospital Emergency Care. Unfortunately, this is from 1999 and I don’t have the issue. I used Medline to find the article but was only able to come up with the abstract. Here is the abstract from the cited study[2]:

INTRODUCTION: Traditional EMS teaching identifies mechanism of injury as an important predictor of spinal injury. Clinical criteria to select patients for immobilization are being studied in Michigan and have been implemented in Maine. Maine requires automatic immobilization of patients with “a positive mechanism” clearly capable of producing spinal injury. OBJECTIVE: To determine whether mechanism of injury affects the ability of clinical criteria to identify patients with spinal injury. METHODS: In this multicenter prospective cohort study, EMS personnel completed a check-off data sheet for prehospital spine-immobilized patients. Data included mechanism of injury and yes/no determinations of the clinical criteria: altered mental status, neurologic deficit, evidence of intoxication, spinal pain or tenderness, and suspected extremity fracture. Hospital outcome data included confirmation of spinal injury and treatment required. Mechanisms of injury were tabulated and rates of spinal injury for each mechanism were calculated. The patients were divided into three different high-risk and low-risk groups. RESULTS: Data were collected for 6,500 patients. There were 209 (3.2%) patients with spinal injuries identified. There were 1,058 patients with 100 (9.4%) injuries in the first high-risk mechanism group, and 5,423 patients with 109 (2%) injuries in the first low-risk group. Criteria identified 97 of 100 (97%) injuries in the high-risk group and 102 of 109 (94%) in the low-risk group. Two additional data divisions yielded identical results. CONCLUSION: Mechanism of injury does not affect the ability of clinical criteria to predict spinal injury in this population.

So the first thing that stands out to me is the year the study was done. 1999 was 10 years ago. Sure, it isn’t that long ago, but think of how much things change in the medical field in a matter of a few years. That doesn’t mean that the data isn’t valid though. The next thing that stands out is the study itself. It is questioning the relevance of mechanism of injury(MOI)in determining a cervical spine injury, not the ability of a paramedic to adequately clear a cervical spine.

This study gave the paramedics a set list of criteria, it didn’t expand off of the paramedic’s assessment skill. The study used paramedics in their research, but they were not testing the medics, just the method. So if the criteria were invalid, how does this reflect on the assessment skill of a paramedic?

Unfortunately this abstract leads a lot to the imagination. I’m not sure if the low risk group was intended to be injury free and ended up with 94% of them having injuries (highly unlikely). It seems to me like their low risk criteria appropriately identified 94% of the injuries and the high risk criteria caught 97% of the injuries. That seems to have pretty good specificity to me. I am still looking for the full text for this study (hint hint Rogue Medic).

The conclusion pretty much states that MOI does not effect clinical criteria when predicting spinal cord injury. Does this mean that a possible spinal cord injury is not at all predictable by the MOI. I didn’t find conclusive evidence (be it just an abstract) that states paramedics should not be clinically clearing the cervical spine in the field.

That isn’t exactly what I am looking for though. Without evidence of benifit, we wouldn’t be practicing evidence-based medicine. The next refference that Trauma.org cited was a study from The Journal of Trauma. Once again, all I could find (even in my college’s extensive database) was the abstract[3]:

OBJECTIVE: Determine the level of agreement between emergency medical technicians (EMTs) and emergency physicians (EPs) when applying an existing emergency medical services/fire department protocol for out-of-hospital clinical cervical spine injury (CSI) clearance in blunt trauma patients. METHODS: Prospective observational study of consecutive blunt trauma patients transported by emergency medical services/fire department during a 3-month study period. The setting was an urban Level I trauma center. Measurement of interrater agreement (kappa) was determined. RESULTS: Mean age of the 190 patients was 34+/-19 years (range, 6 -98 years). Fifty-nine percent of the patients were male. One hundred forty-six patients (77%) were immobilized by EMTs; 17 of these patients were clinically cleared by EPs. Forty-four patients (23%) were clinically cleared by EMTs and presented without CSI precautions; of these, 61% (27 of 44) were immobilized by EPs and 57% (25 of 44) had cervical spine radiographs obtained. Overall, 141 patients (74%) required radiographic clearance. CSI were detected in five patients (2.6%); all five were immobilized in the out-of-hospital setting. Overall disagreement between EMTs and EPs regarding out-of-hospital CSI clearance occurred in 44 patients (23%) (kappa=0.29; 95% confidence interval, 0.15-0.43; p less than 0.01). CONCLUSION: Significant disagreement in clinical CSI clearance exists between EMTs and EPs. Further research and education is recommended before widespread implementation of this practice.

An even older study, done in 1998, but the data is still relevant (also, keep in mind, the Trauma.org article is from 2002). This study doesn’t disprove the ability of paramedics, or EMTs for that matter, to clincally clear a cervical spine. This abstract questions whether EMTs and emergency physicians agree. I hate to point this out, but according to the abstract, the EMTs properly immobilized every patient that came back with a positive cervical spine injury. This doesn’t disprove the purpose of the study however. What I get out of this is the need for the emergency physicians to be on board with a prehospital spinal clearanace protocol.

These were the only two references cited by Trauma.org. Neither reference seems to disprove the ability of an EMT to clinically clear the cervical spine. What was the original statement in question though?

There is no conclusive evidence in the literature that supports clinical clearance of the spine in the prehospital environment. There is enough variation between prehospital and in-hospital assessments to recommend that prehospital removal of spinal immobilisation be avoided.

We still don’t have the conclusive evidence to support cervical spine clearance. One abstract questioned the relationship between MOI and cervical spine injuries. The other study states that physicians and EMTs disagree, but that isn’t necessarily a definitive reason to avoid prehospital clearance of the cervical spine. Just because the studies were both conducted in the prehospital environment doesn’t mean that they tested the ability of the prehospital personnel.

Part II will include my own research on this topic.

Works Cited

[1]Brohi K. 2002. “Clinical Clearance of Cervical Spine Injury” Trauma.org, Link to article

[2]Domeier RM, Evans RW, Swor RA, Hancock JB, Fales W, Krohmer J, Frederiksen SM, and Shork MA. 1999. “The reliability of prehospital clinical evaluation for potential spinal injury is not affected by the mechanism of injury.” Prehospital Emergency Care: Official Journal Of The National Association Of EMS Physicians And The National Association Of State EMS Directors 3, no. 4: 332-337. MEDLINE with Full Text, EBSCOhost (accessed May 30, 2009).

[3]Meldon SW, Brant TA, Cydulka RK, Collins TE, and Shade BR. 1998. “Out-of-hospital cervical spine clearance: agreement between emergency medical technicians and emergency physicians.” The Journal Of Trauma 45, no. 6: 1058-1061. MEDLINE with Full Text, EBSCOhost (accessed May 30, 2009).

Filed Under: Research, Trauma

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