Tag Archives: ICP

General

Targeted Hypernatremia In Trauma Brain Injury

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Traumatic brain injury (TBI) frightens and confuses most trauma professionals. The brain and its workings are a mystery, and there is very little real science behind a lot of what we do for TBI. One thing that we do know is that intracranial hypertension is bad. And another is that we do have some potent drugs (mannitol, hypertonic saline) to treat it emergently. 

So if we can “dry out” the brain tissue on a moment’s notice and drop the ICP a bit with a hit of sodium, doesn’t it stand to reason that elevating the sodium level constantly might keep the brain from becoming edematous in the first place? Many neurosurgeons buy into this, and have developed protocols to maintain serum sodium levels in the mid-140s and higher. But what about the science?

A nice review was published in Neurocritical care which identified the 3 (!) papers that have promoted this practice in humans with TBI. In general, there was a decrease in ICP in the patients in the cited papers. Unfortunately, there were also a number of serious and sometimes fatal complications, including pulmonary edema and renal failure requiring hemodialysis. These complications generally correlated with the degree of hypernatremia induced. Papers were also reviewed that involved patients with other brain injury, not caused by trauma. Results were similar. 

Bottom line: There is no good literature support, standard of care, or even consensus opinion for prophylactically inducing hypernatremia in patients with TBI. The little literature there is involves patients with severe TBI and ICP monitors in place. There is nothing written yet that justifies the expense (ICU level care) and patient discomfort (frequent blood draws) of using this therapy in patients with milder brain injury and a reliable physical exam. If you want to try out this relatively untried therapy, do us all a favor and design a nice study to show that the benefits truly outweigh the risks. 

And if you can point me to some supportive literature that I’ve missed, please do so!

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References:

  • Induced and sustained hypernatremia for the prevention and treatment of cerebral edema following brain injury. Neurocrit Care 19:222-231, 2013.
  • Continuous hyperosmolar therapy for traumatic brain injury-induced cerebral edema: as good as it gets, or an iatrogenic secondary insult? J Clin Neurosci 20:30-31, 2013.
  • Continuous hypertonic saline therapy and the occurrence of complications in neurocritically ill patients. Crit Care Med 37(4):1433-1441, 2009. -> Letter to the editor Crit Care Med 37(8):2490-2491, 2009.
General

Can You Teach A Trauma Surgeon To Insert An ICP Monitor?

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You’ve heard the statistics about the graying of our society. The proportion of older people is growing rapidly. Well, there are only about 4400 neurosurgeons in the US, and they are aging as well. Nearly a third are older than 55 years.

This leaves a relatively small number of neurosurgeons tasked with helping to take care of trauma patients. Many Level II centers are hard pressed to maintain their neurotrauma services. Even basic procedures like ICP monitor placement may require transfer to another center.

The group at Miami Valley Hospital in Dayton looked at their experience with training surgeons to insert intraparenchymal ICP monitors (not EVD devices) over a 6 year period. Their trauma surgeons, as well as surgical residents were trained by watching a video, practicing in a cadaver lab under the supervision of a neurosurgeon, and being proctored by a neurosurgeon while placing them in three patients. Surgical residents could place the monitor if directly supervised by a surgeon.

Here are the factoids:

  • Of 410 monitors placed, 298 were placed by surgeons and 112 by neurosurgeons
  • The surgeons placed 188 Licox monitors and 91 Caminos. The type was not recorded in 19.
  • Surgeon complication rate was 3% (9 patients), and the neurosurgeon rate was 0.8% (1 patient). None were major of life-threatening.
  • Most of the complications were malfunction of the device. There were 2 dislodgements in the surgical group, and 1 in the neurosurgeon group.

Bottom line: This one’s a little tough to interpret. Yes, the number of complications (malfunction) is higher with the surgeons. But the numbers are small, and this difference does not reach statistical significance. I do worry that the training is a bit too sketchy. But I think that this procedure will soon enter the skillset of many acute care surgeons, especially those working at hospitals in more rural settings. This will be the quickest way to begin high quality neurotrauma care for patients who are injured in areas not served by highest level trauma centers.

Related post:

Reference: Successful placement of intracranial pressure monitors by trauma surgeons. J Trauma 76(2): 286-291, 2014.

General

Can You Teach A Trauma Surgeon To Insert An ICP Monitor?

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You’ve heard the statistics about the graying of our society. The proportion of older people is growing rapidly. Well, there are only about 4400 neurosurgeons in the US, and they are aging as well. Nearly a third are older than 55 years.

This leaves a relatively small number of neurosurgeons tasked with helping to take care of trauma patients. Many Level II centers are hard pressed to maintain their neurotrauma services. Even basic procedures like ICP monitor placement may require transfer to another center.

The group at Miami Valley Hospital in Dayton looked at their experience with training surgeons to insert intraparenchymal ICP monitors (not EVD devices) over a 6 year period. Their trauma surgeons, as well as surgical residents were trained by watching a video, practicing in a cadaver lab under the supervision of a neurosurgeon, and being proctored by a neurosurgeon while placing them in three patients. Surgical residents could place the monitor if directly supervised by a surgeon.

Here are the factoids:

  • Of 410 monitors placed, 298 were placed by surgeons and 112 by neurosurgeons
  • The surgeons placed 188 Licox monitors and 91 Caminos. The type was not recorded in 19.
  • Surgeon complication rate was 3% (9 patients), and the neurosurgeon rate was 0.8% (1 patient). None were major of life-threatening.
  • Most of the complications were malfunction of the device. There were 2 dislodgements in the surgical group, and 1 in the neurosurgeon group.

Bottom line: This one’s a little tough to interpret. Yes, the number of complications (malfunction) is higher with the surgeons. But the numbers are small, and this difference does not reach statistical significance. I do worry that the training is a bit too sketchy. But I think that this procedure will soon enter the skillset of many acute care surgeons, especially those working at hospitals in more rural settings. This will be the quickest way to begin high quality neurotrauma care for patients who are injured in areas not served by highest level trauma centers.

Related post:

Reference: Successful placement of intracranial pressure monitors by trauma surgeons. J Trauma 76(2): 286-291, 2014.

General

ICP Monitoring: Less Is More?

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Management of severe traumatic brain injury (TBI) routinely involves monitoring and control of cerebral perfusion pressure. Monitoring is typically accomplished with an invasive monitor, with the extraventricular drain (EVD) and fiberoptic intraparenchymal monitors (IP) being the most common.

The extraventricular drain is preferred in many centers because it not only monitors pressures, but it can also be used to drain cerebrospinal fluid (CSF) to actively try to decrease intracranial pressure (ICP). But could less really be more? Surgeons at Massachusetts General reviewed 229 patients with one of these monitors, looking at outcomes and complications. They found the following interesting results:

  • There was no difference in mortality between the two monitor types
  • The EVD patients did not require surgical decompression as often, possibly because of the ability to decrease ICP through drainage
  • The EVD patients were monitored longer, and had a longer ICU length of stay. This was also associated with a longer hospital length of stay.
  • Complications were much more common in the extraventricular drain group (31%). The most common complications were no drainage / thrombosis (15%) and malposition (10%). Hemorrhage only occurred in 1.6% of patients. 
  • Fiberoptic monitors had a lower complication rate (8%). The most common was malfunction leading to loss of monitoring (12%). Hemorrhage only occurred in 0.6% of patients.

Bottom line: Don’t change your monitoring technique yet. Much more work needs to be done to flesh out this small retrospective study. But it should prompt us to take a critical look for better indications and contraindications for each type of monitor.

Reference: Intraparenchymal versus extracranial ventricular drain intracranial pressure monitors in traumatic brain injury: less is more?J Am Coll Surg 214(6):950-957, 2012.

General

Placement of ICP Monitors By Non-Neurosurgeons

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Traumatic brain injury (TBI) is a common injury world-wide, but neurosurgeons are scarce. Traditionally, neurosurgeons are the ones to place invasive monitors to watch intracranial pressure (ICP). But what about injured people who are taken to a hospital where there is no available neurosurgeon?

A group at Wichita, Kansas looked at their 10 year experience with ICP monitor placement, where it can be done by neurosurgeons, trauma surgeons or general surgical residents (under trauma surgeon supervision). A total of 63 were placed by neurosurgeons, 30 by trauma surgeons, and 464 by residents under supervision. The usual demographics, including hospital stay, were the same across groups. There were essentially no significant differences based on who placed the monitor. Curiously, the article does not state whether the monitors were extradural or intraventricular, or both. The discussion section alludes to the fact that they were “parencyhmal.”

There were only three iatrogenic bleeds, and all occurred with resident placed monitors. None were clinically significant. Malfunction rate was about 5% across all groups. Monitors had to be replaced at some point in about 11% of all three groups. One CNS infection occurred in a patient with a resident-placed monitor.

Bottom line: With proper training and supervision, ICP monitors can be placed by just about anyone. This is particularly important in more rural locations where there are few if any neurosurgeons. But as always, this process needs to be monitored carefully by the hospital’s Trauma Performance Improvement / Patient Safety program (PIPS).

Related posts:

Reference: Placement of intracranial pressure monitors by non-neurosurgeons: excellent outcomes can be achieved. J Trauma 73(3):558-563, 2012.