Journal of Trauma and Acute Care Surgery:
AAST 2013 Plenary Paper
Successful placement of intracranial pressure monitors by trauma surgeons
Ekeh, Akpofure Peter MD; Ilyas, Sadia MD; Saxe, Jonathan M. MD; Whitmill, Melissa MD; Parikh, Priti PhD; Schweitzer, Jeffrey S. MD, PhD; McCarthy, Mary C. MD
From the Section of Acute Care Surgery (A.P.E., S.I., J.S., M.W., P.P., M.C.M.), Department of Surgery, and Department of Neurosurgery (J.S.S.), Wright State University School of Medicine, Dayton, Ohio.
Submitted: September 14, 2013, Revised: October 15, 2013, Accepted: October 15, 2013.
This study was presented at the 72nd annual meeting of the American Association for the Surgery of Trauma, September 18–21, 2013, in San Francisco, California.
Address for reprints:Akpofure Peter Ekeh, MD, Miami Valley Hospital, CHE 7000, 1 Wyoming Street, Dayton, OH 45409; email: firstname.lastname@example.org.
The Brain Trauma Foundation guidelines advocate for the use of intracranial pressure (ICP) monitoring following traumatic brain injury (TBI) in patients with a Glasgow Coma Scale (GCS) score of 8 or less and an abnormal computed tomographic scan finding. The absence of 24-hour in-house neurosurgery coverage can negatively impact timely monitor placement. We reviewed the safety profile of ICP monitor placement by trauma surgeons trained and credentialed in their insertion by neurosurgeons.
In 2005, the in-house trauma surgeons at a Level I trauma center were trained and credentialed in the placement of ICP parenchymal monitors by the neurosurgeons. We abstracted all TBI patients who had ICP monitors placed during a 6-year period. Demographic information, Injury Severity Score (ISS), outcome, and monitor placement by neurosurgery or trauma surgery were identified. Misplacement, hemorrhage, infections, malfunctions, and dislodgement were considered complications. Comparisons were performed by χ2 testing and Student’s t tests.
During the 6-year period, 410 ICP monitors were placed for TBI. The mean (SD) patient age was 40.9 (18.9) years, 73.7% were male, mean (SD) ISS was 28.3 (9.4), mean (SD) length of stay was 19 (16) days, and mortality was 36.1%. Motor vehicle collisions and falls were the most common mechanisms of injury (35.2% and 28.7%, respectively). The trauma surgeons placed 71.7 % of the ICP monitors and neurosurgeons for the remainder. The neurosurgeons placed most of their ICP monitors (71.8%) in the operating room during craniotomy. The overall complication rate was 2.4%. There was no significant difference in complications between the trauma surgeons and neurosurgeons (3% vs. 0.8%, p = 0.2951).
After appropriate training, ICP monitors can be safely placed by trauma surgeons with minimal adverse effects. With current and expected specialty shortages, acute care surgeons can successfully adopt procedures such as ICP monitor placement with minimal complications.
LEVEL OF EVIDENCE
Therapeutic/care management study, level IV.
Traumatic brain injury (TBI) remains a significant cause of morbidity and mortality in the United States and worldwide. Annually in the United States, there are more than 200,000 hospitalizations and 50,000 deaths arising from various mechanisms including falls, motor vehicle crashes, and firearm-related injuries.1 The aging of the population and the increasing use of oral anticoagulants for the treatment of cardiovascular diseases have further complicated TBI patient care—particularly in the elderly populations.2–4
Trauma centers are tasked with the management of a wide spectrum of head-injured patients. Evidence-based guidelines for the optimal management of TBI patients were first proposed by the American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons Joint Section on Neurotrauma and Critical Care in 1996 and further updated in 2000 and 2007.5–7 These Brain Trauma Foundation (BTF) guidelines recommend the use of intracranial pressure (ICP) monitoring in patients with a Glasgow Coma Scale (GCS) score of 8 or less and an abnormal computed tomographic scan finding. Adherence to this and other BTF guidelines has been demonstrated to improve outcomes and decrease the cost of care in TBI patients.8–11
ICP monitoring is achieved either by the placement of a ventriculostomy or an intraparenchymal monitor. The placement of these devices requires skilled personnel who also possess the cognitive ability to manage and respond appropriately to the readings derived from them. This task has naturally fallen to the neurosurgeons, who traditionally direct the care of TBI patients. The shortage of neurosurgical coverage in many areas, however, can present a barrier to the timely placement of ICP monitors. The absence of in-house 24-hour neurosurgery coverage, particularly in hospitals where there is no neurosurgical residency, further complicates the issue.
We reviewed our experience with training trauma (acute care) surgeons to place ICP monitors in TBI patients, addressing the safety issues, identifying complications arising from their insertion, and comparing their results with those of neurosurgeons.
PATIENTS AND METHODS
In 2005, the acute care surgeons at Miami Valley Hospital, Dayton, Ohio, an American College of Surgeons–verified Level I trauma center, were trained and credentialed in the placement of two types of ICP intraparenchymal monitors—the Camino Parenchymal Intracranial Pressure Monitor (Integra LifeSciences, Plainsboro, NJ) and the Licox Brain Tissue Oxygen Monitor (Integra LifeSciences). The training consisted of viewing two 10-minute instructional videos demonstrating ICP monitor placement, proctoring by a neurosurgeon in the cadaver laboratory and then subsequent supervised placement of three monitors in actual patients to achieve hospital credentialing. New surgeons joining the panel were required to go through similar training—watching the instructional videos, placement in cadavers, and then performing a minimum of three procedures on live patients before official credentialing. During a monthly cadaver procedure laboratory for general surgery residents on their acute care surgery rotation, ICP monitor placement is one of the procedures practiced. The instructional video is also available to the residents during their intensive care unit (ICU) rotation.
The ICP monitors are inserted in TBI patients for the indications outlined in the BTF guidelines after consultation with the attending neurosurgeon on call. The surgical ICU (SICU) team performs treatment of high ICPs, maintenance of cerebral perfusion pressure, and other neurocritical care management in extensive collaboration with the attending neurosurgeon in each case. The SICU team is lead by acute care surgeons certified by the American Board of Surgery in surgery and surgical critical care. The SICU team and the neurosurgeons use the ICP monitor readings in the routine management of these TBI patients.
From the trauma registry, we retrospectively identified all TBI patients who had ICP monitors placed between January 2006 and December 2011, noting demographic information, Injury Severity Score (ISS), ICU length of stay (LOS), overall LOS, and eventual outcome. The type of monitor placed (ICP bolt or ventriculostomy) and who placed the monitor (neurosurgeon or acute care surgeon) was also noted. The acute care surgeons were credentialed only in the placement of parenchymal monitors and not ventriculostomies. By hospital policy, all ICP monitors placed must have the supervising acute care surgeon physically present during their insertion. Surgical residents were not permitted to place them without direct supervision.
By chart review, complications proximately arising from the ICP monitor placement were sought and identified. Misplacement, hemorrhage, malfunctions, and dislodgement were considered complications. Comparisons were made between ICP monitors placed by the neurosurgeons and the acute care surgeons using χ2 analysis and Student’s t tests.
During the 6-year period studied, 430 patients had ICP monitors placed for TBI. The service that placed the monitor (acute care surgery or neurosurgery) was noted in each case. The responsible service could not be determined in 20 patients, who were therefore excluded from analysis.
In the 410 patients studied, the mean (SD) age was 40.9 (18.9) years, and 73.7% were male. The mean (SD) ISS was 28.3 (9.4), and mean (SD) LOS was 19 (16) days. The overall mortality was 36.1% in the entire group. Motor vehicle crashes and falls were the most common mechanisms of injury (35.2% and 28.7%, respectively). There were a total of 397 ICP parenchymal monitors (96.8%) and 13 ventriculostomies (3.2%) placed.
The acute care surgeons placed 72.7% of the monitors, while the neurosurgeons placed the rest. Most of the ICP monitors placed by the neurosurgeons (71.8%) were inserted in the operating room during emergency craniotomy. As shown in Table 1, patients in both groups had similar demographics and LOS (Table 1). The mortalities in the acute care surgeon and neurosurgeon groups was 36.9% and 30.4%, respectively (p= 0.2614).
Of the 298 ICP bolts placed by acute care surgeons, 188 (63.1%) were Licox monitors, 91 (30.5%) were of the Camino variety, and 19 (6.4%) were undetermined. The acute care surgeons did not insert ventriculostomies.
The overall complication rate associated with ICP monitor insertion was 2.4%. In the acute care surgeons’ group, the complication rate was 3% (9 of 298), and in the neurosurgeons’ group, the complication rate was 0.8% (1 of 112), which was not significantly different (p = 0.3762). There were no major or life-threatening complications, such as hemorrhage or infection in either group. The complications noted were primarily dislodgements and malfunctions. The specific complications are listed in Table 2.
According to a 2010 estimate by the American College of Surgeons, there are approximately 4,400 active neurosurgeons in the United States—one third is older than 55 years. This computes to 1.44 neurosurgeons per 100,000 persons.12 Furthermore, not all neurosurgeons are involved in trauma care. In view of these realities and with the constant increase in an aging population more vulnerable to head injury, providing optimal management of TBI patients will require novel and realistic care arrangements.
The adoption of new procedures or skills always requires adequate training, quality assurance, judicious monitoring, and the identification of adverse outcomes. This study has demonstrated that acute care surgeons, who typically are in-house, can play a pivotal role in managing this aspect of TBI without any major untoward complications.
As noted in the results, in the 298 ICP monitors placed by acute care surgeons, there were no major complications. The complication profile was limited to primarily malfunctions and displacements. It is, however, recognized that malfunctions could be caused by improper anatomic placement. Monitors with problems were replaced. The issues of dislodgement were typically system issues relating to bedside patient care and transport, which were appropriately addressed by the performance improvement process. It is noted that the opening pressures were significantly lower in the neurosurgery group. This could reflect the fact most of these monitors (>70% of them) were placed in the operating room after cranial decompression procedures.
The difference in the complication rate between the acute care surgeons (3.1%) and neurosurgeons (0.8%) was neither statistically significant nor clinically significant.
The concept of nonneurosurgeons placing ICP monitors is not novel. Barber et al.13 from Wichita, Kansas, demonstrated safe insertion by both neurosurgeons and nonneurosurgeons and proposed that this procedure be adopted as a core skill for trauma surgeons and surgical residents. This study was a follow-up from the same institution a few years earlier, which had similar conclusions.14 Ko and Conforti15 described their success with a training program for the placement of ventriculostomies for “house officers” with minimal complications. The trainees in their case were physicians and physician assistants.
This study adds to this body of literature supporting the concept of safe placement of these devices by nonneurosurgeons. A summary of previous studies is given in Table 3. We have in this study detailed a credentialing process we used that can be adopted by trauma centers where this type of practice will be beneficial to their TBI patients.
A survey of members of the American Association of Surgery of Trauma by Valadka et al.16 reflected that problems with neurotrauma care (including ICP insertion issues) were more frequent when a neurosurgery residency was not present at the institution. In addition, that survey showed that 40% of neurosurgeons (most of whom practiced at academic centers with residents) supported the concept of permitting nonneurosurgeons to place monitors. Perceived delays in neurosurgeon responsiveness in a majority of respondents and gross underuse of ICP monitoring in many of the centers were reported. Such findings could be reflective of the frequent shortage of neurosurgery coverage in certain areas and the challenges of balancing an elective practice with trauma call among other factors. A more recent survey of members of the AANS echoed concerns of perceived medicolegal risk, conflicts with elective practice, and lack of compensation as challenges to the adequate access of trauma patients to neurosurgeons, particularly in certain geographic areas.17
Ventriculostomies are typically preferred to parenchymal monitors by neurosurgeons owing to the added advantage of therapeutic cerebrospinal fluid drainage, easy recalibration, and lower cost. However, they can be more challenging to place and can result in more complications. Another AANS survey by O’Neill et al.18 showed that practicing neurosurgeons had an average of 1.4 attempts in placing each ventriculostomy and junior neurosurgery residents, 2.4 attempts per case. They also reported an estimated 72% to 84% successful ipsilateral cannulation rate. Given these facts, it is our view that the placement of ICP parenchymal monitors is a more reasonable alternative for nonneurosurgeons, which is devoid of the unique complications of ventriculostomy placement. The placement of fiber-optic ICP bolts monitors has been established as a relatively safe procedure with low complication rates and with a track record of placement by nonneurosurgeons.19,20
Noninvasive alternatives for measuring ICP monitoring have been suggested. Venous ophthalmodynamometry, a technique used to register the pressure within the central retinal vein, has demonstrated good correlation with ICP in some studies.21,22 There is a potential for expanded use for this and other technologies that may simplify TBI management options.
One recognized drawback in this study is the lack of reporting the duration of time before ICP bolt placement in the patients—which could have identified the timeliness of monitor placement by acute care surgeons. The variance in numbers of ICP monitors placed by the neurosurgeons and the acute care surgeons as well as the absence of GCS data are other recognized weaknesses.
This discussion will be incomplete without mentioning the recent randomized prospective study by Chesnut et al.23 published in the New England Journal of Medicine, which showed no survival benefit following ICP monitoring in severe TBI patients. These surprising results have generated a lot of discussion but are not likely to, in the immediate term, alter the current TBI management algorithms in the United States and other developed nations.
In summary, our study demonstrates that after appropriate training, ICP parenchymal monitors can be safely placed by trauma surgeons with few complications and corroborates existing literature supporting this concept. With current and expected shortages in specialty coverage and further development of acute care surgery, procedures such as these can be successfully adopted with minimal complications.
A.P.E., M.C.M., and J.S. designed this study. S.I. and A.P.E. performed the data acquisition. A.P.E. and S.I. analyzed and interpreted the data. A.P.E., P.P., M.C.M., J.S.S., and M.W. contributed to drafting and critical revision of the manuscript.
The authors declare no conflicts of interest.
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Dr. Alex B. Valadka (Austin, Texas): I’d like to thank the Association for the privilege of commenting on this paper. I’d like to congratulate Dr. Ilyas on a nice presentation and also thank her and her colleagues for sending me a draft of their manuscript prior to this meeting.
Now, she herself noted in one of her slides that these results have been essentially published before. And this paper doesn’t really break any new ground. So it leaves me with the question of how do I fill a few minutes of podium time trying to be informative and entertaining?
One way is to drive home the point that I think it is important, at least in my practice, to try to use a ventriculostomy as the first line of monitoring because it can be used as a therapeutic tool to drain CSF as well as monitor ICP. I do use parenchymal monitors if I can’t cannulate the ventricle.
A bigger issue is what to do with the information obtained from these monitors. Regardless of who puts these things in, someone needs to know how to treat the patients. Personally, I have been dismayed by the trend in recent years for so-called neurocritical care docs to focus on things like temperature and serum sodium. It seems that very few intensivists who care for TBI patients really understand cerebral metabolism, cerebral blood flow, cerebral pathophysiology, and related processes.
As Dr. Ilyas and her colleagues have shown, the technical insertion of these devices is not that difficult for someone with a surgical background. But knowing the indications for when to put them in and when not to put them in, knowing how to interpret the data, and integrating the care of these patients into the neuroscience service line are much more difficult things to master.
Another problem with this paper is that it describes only short-term periprocedural complications. As I have said from this podium at past meetings of this Association, the real standard for measuring efficacy of interventions in TBI patients is long-term follow-up, which historically has been six months from injury, and now more recent trials are using 12 months or even longer.
In this context, many of you may be familiar with the paper published recently by the Seattle group, led by Randy Chesnut, that actually randomized patients to receiving an intracranial pressure monitor or not as treatment for their severe TBI. Essentially, they found no difference in outcome between the groups. It must be remembered that both groups did get treated; it’s just that one group was treated based on a number from an ICP monitor, and the other was treated based on physical exam and imaging findings. Does ICP monitoring offer an advantage over just empirically treating patients in the way I’ve described? Their paper would suggest no. Undoubtedly, some severe TBI patients don’t need ICP monitoring, but others do. The real questions is how to distinguish between these two groups.
One way to approach this is to imagine that you were asked to participate in a clinical trial investigating an intervention for acute abdominal pain. And that’s all you knew. You just had pain patients, half of whom got placebo, and half of whom got the investigational treatment. And you were including patients with pancreatitis, appendicitis, constipation, colon cancer, peptic ulcer disease, a whole slew of diseases. Of course, your study would fail to show any benefit because your groups would be so heterogeneous.
That’s the problem we have right now with TBI studies. The patient with pure diffuse axonal injury may have the same physical exam, the same Glasgow Coma Scale score, as somebody with an acute subdural hematoma. Yet they are very different diseases. We enroll them in a trial and treat them the same way and wonder why the almost three dozen studies that have been done since 1980 have failed to show a benefit. Well, fortunately, we’re starting to realize that we need to rethink the way we do these things.
We were part of a smaller trial that was initiated right here at San Francisco General by Geoff Manley, and that went well. We just were told we are going to get $19 million of your federal tax dollars to expand that trial to a dozen centers around the country. We’ll be looking at severe TBI in more detail, including things like serum markers, detailed neuropsych testing, and MRI imaging, so we will be able to classify this a little bit more precisely so that in the future you will be able to differentiate your treatment based on the underlying pathophysiologic processes of the guy who is in a coma after he gets hit by a bus.
By redefining TBI and redefining the way we understand it, we will be able to finally get a better understanding of who really needs intracranial pressure monitors and other types of monitors and who doesn’t.
Thanks again to the Association for the privilege of commenting on this paper.
Dr. Stephen R. Smith (Columbia, South Carolina): Thank you very much for a nice presentation. And I agree with your conclusion that this procedure can be done safely by acute care surgeons and can fill the void in many busy trauma centers where neuro-surgical assets are not immediately available.
I have just a couple of questions. First of all, since this has been shown to be a relatively safe procedure with a low complication rate regardless of who is placing the ICP monitors, why has this not caught on?
This is still done by acute care surgeons in a relatively small percentage of trauma centers. And I should note that reimbursement for this procedure is fairly favorable, so I’m somewhat surprised and would be interested to hear what you say why more acute care surgeons are not doing this.
And in reference, specifically to your experience, were you able to determine if the ICP monitors placed by the trauma surgeons were placed at an earlier point in the patient’s course as opposed to waiting for the neurosurgeon to do it at some point later in the operating room or whatever?
Dr. Sadia Ilyas (Dayton, Ohio): Thank you, Dr. Valadka, for your review. Dr. Smith, for as far as why this has not caught on, one of our concerns was that in the literature, while this information has been presented in several studies, there has been no definite training program or credentialing process that has been presented and shown to be safe and effective so we presented our credentialing process in how our trauma surgeons go through being approved to place these ICP monitors in a safe fashion.
As far as the time point to placement of ICP monitors, we weren’t able to determine how long the duration was in between the patient arriving to the ICP monitor placement.
However, we did note that over 70% of the monitors that were placed by our neurosurgery colleagues were placed after a decompressive cranial procedure in the operating room.
Thank you very much for giving us time to present our data.
Top intracranial monitoring; acute care surgery; complications; ICP placement; neurosurgeons
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