Injured Brain Requires Attention to Patient Position, Temperature

An Expert Interview With Bart Besinger, MD, FAAEM

Steven Fox

March 08, 2011

March 7, 2011 (Orlando, Florida) — Editor's note: For emergency department physicians, the challenge of managing patients who present with severe brain injury is one of the most daunting. Positioning of the patient, blood sugar levels, body temperature, blood pressure, and a host of other factors can figure significantly in outcomes.

What's the latest thinking on best practice for treating such patients, and how can emergency department physicians avoid some of the common pitfalls of treating patients with brain injury? "Fine Tuning Treatment of the Injured Brain: Position, Sugar, Temperature, Blood Pressure," was presented by Bart Besinger, MD, FAAEM, here at the American Academy of Emergency Medicine 17th Annual Scientific Assembly, held February 28 to March 2. Dr. Besinger is from the emergency department at the Methodist Hospital in Indianapolis, Indiana.

Medscape Medical News spoke with Dr. Besinger about points to keep in mind when managing patients with brain injury.

Medscape: In what position should patients with brain injury be maintained, and why is it such a vitally important clinical decision?

Dr. Besinger: The head of the bed should be elevated, ideally to 30 to 45 degrees. There are a couple of good reasons for doing that. First and most important, it decreases intracranial pressure. That's extremely important for the patient with a severe head injury.

Another good reason [is that] in mechanically ventilated patients, raising the bed's backrest has been demonstrated to decrease the rate of ventilator-associated pneumonia significantly.

Unfortunately, we sometimes actually lower the patient's head. We put them in the Trendelenburg position to place a central venous line, in spite of the fact that the caliber of the subclavian vein is affected only a little by this maneuver. The Trendelenburg position should be avoided for the brain-injured patient.

Maintaining optimal patient position is easy to do and it costs nothing, but too often that aspect of good care is neglected.

Medscape: If a cervical collar has been applied to the patient, when should it be removed?

Dr. Besinger: As soon as possible. Removing the cervical collar can decrease the intracranial pressure by as much as 2 to 5 mm/Hg. However, clearing the cervical spine of a severely head-injured patient takes time and it often can't be done in the emergency department. When the collar can't be removed right away, it should be checked to make sure it's the right size and that it's not fitted too tightly.

Medscape: What is the role of intensive insulin therapy (IIT) in brain injury?

Dr. Besinger: That's a controversial issue. Intensive insulin therapy for [intensive care unit] patients, including those with head injury, was enthusiastically embraced in the early 2000s. But as more studies of IIT have become available, the benefit of IIT has become less clear.

In brain injury, hyperglycemia is a predictor of mortality and poor neurologic outcome, but aggressive treatment of hyperglycemia with IIT hasn't proven to be beneficial in clinical studies.

One of the downsides of IIT is hypoglycemia, which occurs much more frequently with IIT than it does with conventional insulin therapy. The brain is very sensitive to hypoglycemia.

Medscape: I understand that body temperature can be an especially critical factor in brain injury. How can this best be managed?

Dr. Besinger: Fever increases cerebral metabolic rate and is independently associated with poor outcomes after serious head injury. So it is generally recommended that fever be treated aggressively.

But should we make the patient hypothermic? That's a different matter. Over the past several decades, there has been has been a good deal of research looking at whether or not induced hypothermia is beneficial. It works for victims of cardiac arrest and it is theoretically appealing for head-injury victims as well. Unfortunately, however, the best clinical studies that have looked at this have failed to show a benefit in traumatic brain injury.

Medscape: What about blood pressure? Which is more common in brain-injured patients — hypotension or hypertension — and how should they be managed?

Dr. Besinger: The brain-injured patient may present with either one.

Hypotension — even 1 isolated episode — is associated with poor outcomes and should be managed aggressively to maintain cerebral perfusion.

Hypertension may occur for a variety of reasons — pain, anxiety, an underlying medical condition, or as a physiologic response to maintaining cerebral perfusion in the setting of increased [intracranial pressure]. Because elevated blood pressure may be associated with a beneficial response, it is generally prudent to avoid intervention. The consequences of overshoot hypotension from the administration of antihypertensive medications could be detrimental.

If the blood pressure is unacceptably high, analgesics or sedatives are a reasonable first-line therapy. But what is unacceptably high? There is no magic number. It's essential that management be tailored to the individual patient.

Medscape: Do you have a few final "pearls" for clinicians managing patients with brain injury?

Dr. Besinger: Remember the little things. Severely head-injured patients are among the most critical that we care for in the emergency department, and we focus, as we should, on their initial resuscitation — the ABCs (airway, breathing, and circulation).

But it's important to attend to the small details as well, like elevating the patient's head. If you're worried about spinal injury, you can place the patient in the reverse Trendelenburg position, which keeps the spine in a neutral position.

Consider positioning a continuous core temperature monitor so temperature elevations can be identified early and treated.

And finally, I'd say, treat hypotension aggressively but treat hypertension very cautiously, if at all.

Dr. Besinger has disclosed no relevant financial relationships.

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