The Golden Hour in Acute Head Injury

Posted by Patrick Lickiss on Apr 3, 2012 in General, Research, Treatment | 0 comments

The “Golden Hour” is one of those topic in EMS which people feel very strongly about.  Plenty of research exists on both sides of the issue and further studies are released all the time which tend to compound the issue rather than clarify it.  The Golden Hour,  to review, is the time interval said to be linked with survival of a traumatic injury and is measure from the time of injury until the patient receives surgical intervention.  The idea, of course, is that getting a patient to surgery within an hour will improve outcomes.  It is important to note, however, that there a certain subset of trauma patients who have fatal injuries regardless of time to intervention, sometimes it is just your day to go.

A study was released recently for Injury looking at what might be a grey area in the argument about the Golden Hour: severe head injury.  Let’s take a look at the abstract:

Injury. 2012 Feb 13. [Epub ahead of print]

Redefining the golden hour for severe head injury in an urban setting: The effect of prehospital arrival times on patient outcomes.

Dinh MM, Bein K, Roncal S, Byrne CM, Petchell J, Brennan J.

Royal Prince Alfred Hospital, Trauma Office level 10, Missenden Road, Camperdown, NSW 2050, Australia.

BACKGROUND: In patients with severe head injuries, transportation to a trauma centre within the “golden hour” are important markers of trauma system effectiveness but evidence regarding impacts on patient outcomes is limited.

OBJECTIVE: To determine the effect of patient arrival within the golden hour on patient outcomes.

METHODS: A retrospective cohort of adult patients with severe head injuries (head AIS≥3) arriving within 24h of injury was identified using the trauma registry from 2000 to 2011. Survival analysis was used to determine the effect of patient arrival time on overall mortality. Study outcomes were in hospital mortality and survival to hospital discharge without requiring transfer for ongoing rehabilitation or nursing home care.

RESULTS: There was a significant association with mortality with each incremental minute of patient arrival (HR 1.002, 95%CI 1.001-1.004, p=0.001). There was however no survival benefit observed for patients arriving within 60min of injury time (HR 0.77, 95%CI 0.50-1.18, p=0.22) but an apparent benefit for those presenting within 2h of injury time (HR 0.31, 95%CI 0.15-0.66, p=0.002). Patient arrival within 60min of injury time was associated with increased odds of survival to hospital discharge without requiring ongoing rehabilitation (OR 1.78, 95%CI 1.14-2.79, p=0.01).

CONCLUSION: A survival benefit exists in patients arriving earlier to hospital after severe head injury but the benefit may extend beyond the golden hour. There was evidence of improved functional outcomes in patients arriving within 60min of injury time.

So what’s your take? First of all, let me say that I am pleased to see more researchers looking at patients who are surviving illness and injury AND retaining functionality.  Simply surviving a head injury or cardiac arrest but being unable to function at all should not be considered a success of medicine.  The patient who survived AND did not require ongoing rehabilitation were counted an analyzed.

Second, this is looking at an urban trauma system.  Given the prevalence of research and teaching institutions in urban centers, this type of research tends to be focused there.  I am in an urban system so this is useful for me, but it would be nice to see more research targeted at rural trauma patients.

Third, the results are fairly interesting.  Patients appear to be more likely to survive if treated within the first two hours.  They are more likely, however, to be discharged functionally intact if treated within the first 60 minutes.  Sounds like the “Golden Hour” may work here.  There was, though, no benefit associated with treatment before 60 minutes.

So what does this all mean?  Clearly, severe head injury patients are time sensitive.  For the purposes of this study, however, that only means that they are seen within one hour of their time of injury.  There is no noted benefit to being seen before then.  Perhaps these patients fall into the growing category of those who do not require “lights and sirens” transport.  If these patients are maintaining an airway and vital signs, maybe we can forgo the risk of running code into the hospital?  What do you think?  Let me know in the comments.

Differential Diagnosis: 62 year old Female – Fall

Posted by Patrick Lickiss on Mar 29, 2012 in Assessment, General, Treatment | 1 comment

You are dispatched Code 2 (no lights and sirens) to a report an elderly female who fell on the steps of the library. It rained recently and has been cold out. There have been several slip-and-falls responded to around the city this morning.

As you pull up on scene, you find that your patient is still leaning up against the steps and has been covered with a blanket by a bystander. The patient tracks you visually when you walk up and appears to be in obvious pain. Witnesses report that the patient was walking down the ice-covered steps and fell. Both the patient and bystanders state that she did not have a loss of consciousness nor did she strike her head.

As you begin to assess the patient, she reports that she only has pain to her right knee. She denies feeling dizzy or weak before the fall. She has a history of hypertension and is currently taking Atenolol. She reports an allergy to aspirin. Enlisting the help of bystanders, you move the patient to the gurney and into the ambulance out of the cold. You now have an opportunity to directly visualize her knee:

Yes, I know it's a picture of a man's knee...

There is obvious deformity to the knee joint and swelling to the back of the knee.  The patient has good circulation, sensory and motor distal to the injury site.  She is in significant pain.

What are your potential differential diagnoses?  What is your treatment?  What hospital services do you anticipate that she will need?  Anything else?

Image via MedScape

Laryngospasm and Hypoxia after Ketamine

Posted by Patrick Lickiss on Feb 22, 2012 in General, Research, Treatment | 1 comment

There has been some talk recently about wanting to include ketamine in the pharmacopea for EMS providers. An interesting case study was published recently looking at a potential complication of providing ketamine for sedation:

Laryngospasm and Hypoxia after Intramuscular Administration of Ketamine to a Patient in Excited Delirium.
Prehosp Emerg Care. 2012 Jan 17;

Authors: Burnett AM, Watters BJ, Barringer KW, Griffith KR, Frascone RJ

ABSTRACT: An advanced life support emergency medical services (EMS) unit was dispatched with law enforcement to a report of a male patient with a possible overdose and psychiatric emergency. Police restrained the patient and cleared EMS into the scene. The patient was identified as having excited delirium, and ketamine was administered intramuscularly. Sedation was achieved and the patient was transported to the closest hospital. While in the emergency department, the patient developed laryngospasm and hypoxia. The airway obstruction was overcome with bag-valve-mask ventilation. Several minutes later, a second episode of laryngospasm occurred, which again responded to positive-pressure ventilation. At this point the airway was secured with an endotracheal tube. The patient was uneventfully extubated several hours later. This is the first report of laryngospam and hypoxia associated with prehospital administration of intramuscular ketamine to a patient with excited delirium.

Now I don’t know a whole lot about the pharmacodynamic of ketamine, is this something we need to worry about?  Is this an expected side effect in a portion of the population?  Is this simply an abbarency?  Has your system looked at alternate sedatives like ketamine? Let me know!

Adequacy of Pain Management in Children with Long Bone Fractures

Posted by Patrick Lickiss on Feb 15, 2012 in General, Research, Treatment | 8 comments

Continuing last week’s theme of trauma related research, today’s study is from the journal Pediatric Emergency Care and looks at emergency room management of pain in pediatric patients suffering from isolated long bone fractures. The researchers underwent a retrospective study to determine if patients ages 0-15 years were given adequate dosing based on standard, inadequate dosing or no pain medication at all when they presented with single long-bone fracture.

Here’s the abstract:

Pediatr Emerg Care. 2012 Jan 20. [Epub ahead of print]

Analgesic Administration in the Emergency Department for Children Requiring Hospitalization for Long-Bone Fracture.

Dong L, Donaldson A, Metzger R, Keenan H.

From the *Intensive Medicine Clincal Program, Intermountain Healthcare; †Department of Pediatrics, University of Utah; ‡Division of Pediatric Surgery, University of Utah School of Medicine, Primary Children’s Medical Center; and §Department of Pediatrics, University of Utah, Salt Lake City, UT.

OBJECTIVES: The objective of the study was to describe analgesia utilization before and during the emergency department (ED) visit and assess factors associated with analgesia use in pediatric patients with isolated long-bone fractures.

METHODS: This retrospective cohort study of patients aged 0 to 15 years with a diagnosis of an isolated long-bone fracture was conducted at a single, level I pediatric trauma center. Patients included were treated in the ED within 12 hours of injury and subsequently admitted to the hospital from January 2005 through August 2007. Pain medication received within the first hour after ED arrival was categorized based on prespecified standard doses as follows: adequate, inadequate, and no pain medication received. Cumulative logistic regression analysis assessed factors associated with analgesia use.

RESULTS: There were 773 patients with isolated long-bone fracture included in the analysis. Overall, 10% of patients received adequate pain medicine; 31% received inadequate medicine; and 59% received no pain medicine within 1 hour of ED arrival. In multivariable analysis, children with younger age, longer time from injury to ED arrival, closed fractures, and upper-extremity fractures were less likely to receive adequate pain medicine during the ED visit. Of those transported by emergency medical services directly from the scene to the ED, 9 (10%) of 88 were given pain medication during transport.

CONCLUSIONS: Pain management in pediatric patients following a traumatic injury has been recognized as an important component of care. This study suggests that alleviation of pain after traumatic injury requires further attention in both the prehospital and ED settings, especially among the youngest children.

A few interesting items jump out  when reviewing this study.  First, only 10% of patients were treated with adequate amounts of analgesia.  Second, 59% of patients received no pain management within the first hour of arriving.  Just to review, that’s 59% of patient 15 years and younger with long bone fractures receiving no pain medication whatsoever.  Finally, only 10% of patients arriving via EMS were given any pain medication at all.  There was no analysis performed on the adequacy of EMS dosing.  To review, that means that EMS did not give pain medication to 90% of pediatric patient with long bone fractures.  In short, this is unacceptable.

The researchers looked at root cause and found the expected variables: younger age, upper extremity fractures and closed fractures resulted in lower quantities of pain medication.  The EMS-related finding, however, is what upsets me the most about this paper.  If my son breaks an arm or a leg, the paramedics had better intend on giving him pain medication.  Same with the ED staff.

So what about you?  Do you treat pediatric patients as aggressively for pain as you do adults?  What about your co-workers?  What are some of the things that keep you from treating pediatrics aggressively?  Let me know in the comments.

Are Prehospital Trauma Triage Criteria Effective?

Posted by Patrick Lickiss on Feb 8, 2012 in Assessment, General, Research, Treatment | 0 comments

Chances are, the system you work in has a list of trauma criteria. Patients meeting such criteria are transported to specific trauma hospitals where advanced services are available. Some systems present their trauma criteria as guidelines while others are set in stone. Some systems mandate that certain criteria be activated while others are left to the discretion of the paramedics. The real question is: do these criteria even work?

Before answering that question, we need to decide what makes up an effective trauma triage system. In my opinion, an effective trauma system doesn’t miss severe life-threatening injuries and exhibits a minimum level of over-triage.
Why not just activate every trauma patient regardless of severity? A more thorough assessment is better right?

Yes and no. Well, actually no. Thorough assessment is good, unnecessary assessment isn’t.  Think about what happens when you bring in a trauma patient. Depending on the hospital there are up to 15 or so people in the room or immediately on stand-by. This includes physicians, nurses, lab technicians, radiology technicians, respiratory therapists, social workers (my favorite!) and many more. When dedicated to your patient, at least initially, they are unavailable to respond to another patient.

Now think about what happens to your patient: labs, x-rays, CT scans and countless other diagnostics. Each time a vein is punctured, there is a risk of infection. Every x-ray and CT scan involves exposing your patient to radiation which has additive effects over time.  In the end, a trauma system should be judged both on catching serious injuries and not activating patients unnecessarily.

Imagine my pleasure at reading the following excerpt from an Australian study published last year in Injury:

Injury. 2011 Sep;42(9):889-95. Epub 2010 Apr 28.

Differentiation of confirmed major trauma patients and potential major trauma patients using pre-hospital trauma triage criteria.

Cox S, Smith K, Currell A, Harriss L, Barger B, Cameron P.

Strategy & Planning Department, Ambulance Victoria, Australia. Shelley.Cox@ambulance.vic.gov.au

BACKGROUND: There is a paucity of literature comparing trauma patients who meet pre-hospital trauma triage guidelines (‘potential major trauma’) with trauma patients who are identified as ‘confirmed major trauma patients’ at hospital discharge. This type of epidemiological surveillance is critical to continuous performance monitoring of mature trauma care systems. The current study aimed to determine if the current trauma triage criteria resulted in under/over-triage and whether the triage criteria were being adhered to.

METHODS: For a 12-month time period there were 45,332 adult (≥16 years of age) trauma patients transported by ambulance to hospitals in metropolitan Melbourne. This retrospective study analysed data from 1166 patients identified at hospital discharge as ‘confirmed major trauma patients’ and 16,479 patients captured by the current pre-hospital trauma triage criteria, who did not go on to meet the definition of confirmed major trauma. These patients comprise the ‘potential major trauma’ group. Non-major trauma patients (N=27,687) were excluded from the study. Pre-hospital data was sourced from the Victorian Ambulance Clinical Information System (VACIS) and hospital data was sourced from the Victorian State Trauma Registry (VSTR). Statistical analyses compared the characteristics of confirmed major trauma and potential major trauma patients according to the current trauma triage criteria.

RESULTS: The leading causes of confirmed major trauma and potential major trauma were motor vehicle collisions (30.1% vs. 19.2%) and falls (30.0% vs. 48.7%). More than 80% of confirmed major trauma and 24.4% of potential major trauma patients were directly transported to a major trauma service. Overall, similar numbers of confirmed major trauma patients and potential major trauma patients had one or more aberrant vital signs (67.0% vs. 66.4%). Specific injuries meeting triage criteria were sustained by 69.2% of confirmed major trauma patients and 51.4% of potential major trauma patients, while 11.7% of confirmed major trauma patients and 4.6% of potential major trauma patients met the combined mechanism of injury criteria.

CONCLUSIONS: While the sensitivity of the current pre-hospital trauma triage criteria is high, if paramedics strictly followed the criteria there would be significant over-triage. Triage models using different mechanistic and physiologic criteria should be evaluated.

There are a few reasons I like this study, not the least of which is that the following ad campaign came out of Australia:

But I digress.  Basically, I think this study takes a pretty realistic look at what works and what doesn’t in their system.  According to the study authors, their triage criteria (and associated paramedic discretion) catch about 80% of confirmed traumas.  This is respectable sensitivity (ability to identify positive results).  The authors admit, however, that strict adherence to triage criteria would result in unacceptably high over-triage.

With no evidence to back this up, my gut reaction is that most trauma systems suffer from similar over triage, or at least the potential for over triage.

What about your system?  Have you done anything to reduce the amount of over triage for trauma patients?  Are the study authors totally off base?  Let me know in the comments.

Early Increase in Blood Glucose Predicts Poor Outcome

Posted by Patrick Lickiss on Feb 1, 2012 in General, Research, Treatment | 2 comments

In a study just electronically published in Diabetes Care, researchers explore the link, if any, between changes in blood glucose level following return of circulation in patients initially presenting in ventricular fibrillation and ultimate patient outcome.

Take a quick look at the abstract:

Early Increase in Blood Glucose in Patients Resuscitated From Out-of-Hospital Ventricular Fibrillation Predicts Poor Outcome.

Nurmi J, Boyd J, Anttalainen N, Westerbacka J, Kuisma M.

Helsinki Emergency Medical Services, Department of Anesthesia and Intensive Care, Helsinki University Central Hospital, Helsinki, Finland.

OBJECTIVE: To describe the trend of blood glucose immediately after successful resuscitation from out-of-hospital ventricular fibrillation.
RESEARCH DESIGN AND METHODS: Data from cardiac arrest registry supplemented with blood glucose data were analyzed in this population-based observational study. Between 2005 and 2009, a total of 170 adult patients survived to hospital admission after resuscitation from bystander-witnessed cardiac arrest of cardiac origin and ventricular fibrillation as an initial rhythm.
RESULTS: Sufficient data for analysis were available in 134 (79%) patients, of whom 87 (65% [95% CI 57-73]) survived to hospital discharge in Cerebral Performance Category 1 or 2. Blood glucose did not change significantly between prehospital (10.5 ± 4.1 mmol/L) and admission (10.0 ± 3.7 mmol/L) in survivors (P = 0.3483), whereas in nonsurvivors, blood glucose increased from 11.8 ± 4.6 to 13.8 ± 3.3 mmol/L (P = 0.0025).
CONCLUSIONS: Patients who are resuscitated from out-of-hospital ventricular fibrillation, but whose outcome is unfavorable are characterized by significant increase of blood glucose in the ultraacute postresuscitation phase.

WHAT’S IT ALL MEAN?
The first limitation of any study reporting observations from paramedic charts is that the data comes from paramedic charts.  We, as an industry, are notorious for estimating and rounding.  Is a systolic blood pressure 136 or 140?  Does it make a difference?  Sometimes it does, especially when comparing prehospital to in-patient values.  That being said, blood glucose is probably pretty reliably documented because it is easy to pull up the last value on many glucometers.

The second limitation is a frequency of glucometer calibration.  I know EMS systems which dictate that this be done daily and some which never calibrate.  That being said, this study did look for significant changes in blood glucose so my hope would be that they were able to overcome some of those variances.

The third limitation is that they rely on EMS performing a blood glucose on a post arrest patient.  Should this be done routinely?  Probably.  Is it?  Maybe, but who knows.  This limitation may have kept the study population artificially low.

There are a few things I like about this study.  First of all, they focus on V-fib presenting patients with witnessed cardiac arrest.  This is the population which appears to have the best shot at getting out of the hospital alive.

Second, they look only at patients who survived to hospital admission and their metric for “good outcome” is neurologically intact after discharge.  It’s high time that we focused more studies are what actually matters (getting patients out of the hospital alive and functioning) and ignoring what doesn’t (ROSC).

RESULTS
The researchers found that a significant increase in blood glucose from the prehospital setting to the in-patient one is linked to poor outcomes.  It should be noted that this is probably not a causal relationship.  Will this change prehospital care?  Probably not.  Thought if, as a Critical Care provider, you are transferring a post arrest patient and note an increase in blood glucose since the resuscitation in the field it might be wise to expect a re-arrest.

Does your system routinely check blood glucose on post arrest patients?  Do you know how to recall the last reading on your glucometer?  Let me know in the comments.