Category Archives: Abdomen

Best Of AAST #4: Starting VTE Prophylaxis After Solid Organ Injury

Venous thromboembolic disease (VTE) continues to be a major issue in trauma patients. Most trauma centers have prophylaxis guidelines to try to reduce this problem. These guidelines typically recognize specific injuries that increase the risk of bleeding if anticoagulants are given. Typical ones include hemorrhagic injuries to the brain, pelvic and spine fractures, and solid organ injuries.

Typically, VTE prophylaxis starts immediately upon admission. But when these high-risk injuries are present, it is usually delayed for a period of time. Unfortunately, that period may be highly variable. Many centers have adopted 2-3 days to delay administration of low molecular weight heparin in patients with solid organ injury.

The AAST initiated a prospective multi-institutional trial comparing early (<48 hours after admission) and late (>48 hours) administration of prophylactic agents. Patients were older than 16 years, had any number of liver, spleen, or kidney injuries, and were initially treated nonoperatively. Patients who were transferred, died in the ED, were pregnant, had a bleeding disorder, or were taking anticoagulants or platelet inhibitors were excluded. A power analysis was performed, and more than the needed number of patients were enrolled.

Here are the factoids:

  • A total of 1173 patients were enrolled, and there were 589 liver injuries, 569 spleen injuries, and 289 kidney injuries
  • About 75% of patients (864) had early prophylaxis
  • Patients were younger (median 34 years), and two-thirds were male, with a median ISS of 22
  • Early VTE prophylaxis patients had significantly lower rates of VTE (3% vs. 7%)
  • There was no significant difference in failure of nonoperative management (5% early vs. 7% late)
  • The early prophylaxis group received fewer units of blood after prophylaxis started (17% vs. 23%)
  • Patients receiving VTE prophylaxis after 48 hours were 2.2x more likely to develop VTE

The authors concluded that early VTE chemoprophylaxis was associated with lower rates of VTE with no increase in complications. They recommended that it should become the standard of care for these patients.

Bottom line: Seeing such a well-designed and nicely executed study is refreshing. If the facts are borne out in the final manuscript review, this should become the standard of care for VTE prophylaxis in patients with solid organ injuries. 

I wish the authors would have stipulated that the chemoprophylaxis was required to be low molecular weight heparin. Unfortunately, there are still more than a few centers using unfractionated heparin. There could be a difference in efficacy and failure rates between the two. This could complicate the statistical analysis. Hopefully, the presenter will address this during the meeting.

I would also like to see a breakdown of when the early VTE prophylaxis actually started. Were they all close to 48 hours? Or were there enough at 24 hours to show this is also safe and effective?

It’s time for everyone to review their VTE prophylaxis guidelines. Get ready to make some major changes in your patients with solid organ injury!

Reference: When is it safe to start VTE prophylaxis after blunt solid organ injury? A prospective AAST multi-institutional trial. AAST 2023, Plenary paper #23.

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Guidelines For Diagnosis Of Diaphragmatic Injury

In today’s post, I will review the diaphragmatic injury practice guidelines published by the Eastern Association for the Surgery of Trauma (EAST).  I will follow this up on Friday with an interesting delayed diaphragm injury case.

Diaphragm injury is a troublesome one to diagnose. It is essentially an elliptical sheet of muscle that is doubly curved, so it does not lend itself well to diagnosis by axial imaging. The addition of sagittal and coronal reconstructions to a thoracoabdominal CT has been helpful but still has a far from perfect diagnostic record.

From an evaluation standpoint, there are several possibilities:

  • Observation – not generally recommended. It is usually combined with imaging such as a chest x-ray to see if interval changes occur that would indicate the injury.
  • Chest x-ray – this is not often diagnostic, but when herniation of abdominal contents is obvious, the patient most assuredly has an operative problem.
  • Thoracoabdominal CT scan – this technology keeps improving, especially with thinner cuts and different planes of reconstruction. Sometimes even subtle injuries can be detected. But this exam is still imperfect.
  • Laparoscopy or thoracoscopy – this technique yields excellent accuracy when the injury is in an area that can be viewed from the operative entry point chosen.
  • Laparotomy or thoracotomy – this is the ultimate choice and should be nearly 100% accurate. It is almost the most invasive and has more potential associated complications.

EAST reviewed a large body of literature and selected 56 pertinent papers for their quality and design. Then, they critically reviewed them and applied a standard methodology to answer several questions.

Here are the questions with the recommendations from EAST, along with my comments:

  • Should laparoscopy or CT be used to evaluate left-sided thoracoabdominal stab wounds? First, these patients must be hemodynamically stable and not have peritonitis. If either is present, there is no further need for diagnosis; a therapeutic procedure must be performed.
    Left-sided diaphragm injuries from stabs are evil. The hole is small, and since the pressure within the abdomen is greater than the chest, things always try to wiggle their way through this small hole. It can remain asymptomatic if the wiggler is just a piece of fat, but it can be catastrophic if a bit of the stomach or colon pushes through and becomes strangulated. Furthermore, these holes enlarge over time, so more and more stuff can push up into the chest.
    EAST recommends using laparoscopy for evaluation to decrease the incidence of missed injury. However, if the injury is in a less accessible location (posterior), the patient has body habitus issues or adhesions from previous surgery may lead to incomplete evaluation, laparotomy should be strongly considered.
  • Should operative or nonoperative management be used to evaluate right-sided thoracoabdominal penetrating wounds? Note that this is different than the last question. All penetrating injuries (stabs and gunshots) are included, and this one is for management, not evaluation. And the same caveats regarding hemodynamic stability and peritonitis apply. Again, it applies to both stabs and gunshots.
    Unlike left-sided injuries, right-sided ones are much more benign. This is because the liver keeps anything from pushing up through small holes, and they do not tend to enlarge over time due to this protection. For that reason, EAST recommends nonoperative management to reduce operation-related mortality and morbidity.
  • Should stable patients with acute diaphragm injury undergo repair via an abdominal or thoracic approach? This question applies to any diaphragm injury that requires an operation, such as a right-sided penetrating injury or any blunt injury. EAST recommends an approach from the abdomen to reduce morbidity and mortality. However, since abdominal injury frequently occurs in these cases, an approach from the chest limits the ability to identify and repair abdominal injuries. Otherwise, you may find yourself doing a laparotomy in addition to the thoracotomy.
  • Should patients with delayed visceral herniation through a diaphragm injury undergo repair via an abdominal or thoracic approach?  For years, the preferred approach for delayed presentations has been through the chest because the injury is easier to appreciate and repair.  However, if ischemic or gangrenous viscera are present, it will be more challenging to manage and repair from the chest. EAST does not make a specific recommendation for this question and suggests the surgical approach be determined on a case-by-case basis.
  • Should patients with an acute diaphragm injury from penetrating injury without concern for other intra-abdominal injuries undergo open or laparoscopic repair? The quality and quantity of data addressing this question were very low, but EAST recommends laparoscopy to repair these injuries to reduce morbidity and mortality. This includes blunt injuries, which tend to be larger. There were some conversions to an open procedure, especially in the blunt cases. The usual caveats on exposure, injury location, body habitus, and previous surgery apply.

Reference: Evaluation and management of traumatic diaphragmatic injuries: A Practice Management Guideline from the Eastern Association for the Surgery of Trauma. J Trauma 85(1):198-207.

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Leukocytosis After Splenic Injury

Any trauma professional who has dealt with spleen injuries knows that the white blood cell (WBC) count rises afterwards. And unfortunately, this elevation can be confusing if the patient is at risk for developing inflammatory or infectious processes that might be monitored using the WBC count.

Is there any rhyme or reason to how high WBCs will rise after injury? What about after splenectomy or IR embolization? An abstract is being presented at the Clinical Congress of the American College of Surgeons next month that examines this phenomenon.

This retrospective study looked at a convenience sample of 75 patients, distributed between patients who had splenic injury that was either not treated, removed (splenectomy), or embolized. Data points were accumulated over 45 days.

Here are the factoids:

  • 20 patients underwent splenectomy, 22 were embolized, and 33 were observed and not otherwise treated
  • Injury severity score was essentially identical in all groups (19)
  • Splenectomy caused the highest WBC counts at the 30 day mark (17.4K)
  • Embolized patients had mildly elevated WBC levels (13.1K) that were just above the normal range at 30 days
  • Observed patients had high normal WBC values (11.0K) after 30 days
  • Values in observed and embolized patients normalized to about 7K after 30 days; splenectomy patient WBC count remained mildly elevated at 14.1K.
  • The authors concluded that embolization does not result in permanent loss of splenic function (bad conclusion, rookie mistake!)

Bottom line: This study is interesting because it gives us a glimpse of the time course of leukocytosis in patients with injured spleens. If you need to follow the WBC for other reasons, if gives a little insight into what might be attributable to the spleen. Splenectomy generally results in a chronically elevated WBC count, which tends to vary in the mid-teens range. Embolization (in this study) transiently elevates the WBC count, but it then drops back to normal.

The big problem with this study (besides it being small) is that it fails to recognize that there are many different shades of embolization. Splenic artery? Superselective? Selective? I suspect that the WBC count in main splenic artery embolization may behave much like splenectomy in terms of leukocytosis. And the conclusion about splenic function being related to WBC count was pulled out of a hat. Don’t believe it.

Reference: Leukocytosis after Splenic Injury: A Comparison of Splenectomy, Embolization, and Observation. American College of Surgeons Scientific Forum Abstracts pg S164, 2015.

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Colonic Pseudo-Obstruction In Trauma Patients – Part 2

In my last post, I discussed a paper describing the incidence of colonic pseudo-obstruction (CPO), or Ogilvie syndrome, in trauma patients. The paper confirmed my bias that this condition could be a problem in a specific subset of trauma patients. They are generally older men with pelvic or spine fractures, with or without surgical fixation. In addition, some comorbidities like diabetes, obesity, and concomitant head injury increase the incidence.

The usual dogma is that a cecal diameter > 12cm places the patient at risk of perforation. Therefore, as the size of the colon increases, steps should be taken to decompress it definitively. This typically involves neostigmine infusion, which usually requires transfer to the ICU, or colonoscopic decompression.

Until about eight years ago, we managed this issue at Regions Hospital using the IV neostigmine option in the ICU. But then, one of our colorectal surgeons described his experience managing CPO with subcutaneous neostigmine. A light bulb turned on! Intravenous neostigmine requires admission to an ICU at our hospital for continuous monitoring to quickly identify the development of bradycardia.

But subcutaneous neostigmine was not on the naughty list! We developed a practice guideline to identify and exclude patients for whom this drug was contraindicated. And it required monitoring that could be accomplished in a floor bed with brief episodes of continuous EKG monitoring. Our inpatient trauma unit could easily do this. However, it might require a step-down bed in yours.

Here is the guideline. Click the image of the link at the end of this post to download a copy.

Here are the major features of the guideline:

  • Identification. Any patient, especially those with the previously described risk factors, begins daily monitoring with a flat plate abdominal x-ray. Patients with abdominal distension with subjective discomfort or nursing concerns with the distension fall into this category.
  • Trigger. Once distension of any part of the colon, particularly the cecum, exceeds 10 cm, it is time to act. Otherwise, daily monitoring and a bowel regimen continue.
  • Contraindications to neostigmine. If the patient has a recent history of MI, bronchospasm, is on beta-blocker therapy, or has SBP < 90 torr, heart rate < 60, or weight < 50kg, colonoscopic decompression should be carried out.
  • Continuous monitoring must be available for one hour after injection. This requires an appropriate nurse and an EKG monitor. Atropine must be present at the bedside in case bradycardia develops.
  • Up to three doses of SQ neostigmine (1mg) can be given 12 hours apart. If the patient responds with a large bowel movement or passage of gas, it should be confirmed with an abdominal x-ray.
  • Patients with insufficient response must transfer to ICU for IV neostigmine or should be scheduled for an urgent colonoscopy.

Our experience has shown that this guideline is usually very effective. However, a few patients have had a recurrence after 24-48 hours, which is uncommon. The guideline can be repeated if necessary.

Bottom line: A low index of suspicion for CPO in trauma patients is critical. Once the colon perforates, these patients do poorly, and serious complications are common. This guideline allows the trauma service to keep these patients out of the ICU while treating it. But before you implement this, please work closely with your pharmacists to ensure that hospital policy allows using neostigmine outside of an ICU setting.

Colonic Pseudo-Obstruction in Trauma – Practice guideline. Click to download.

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Colonic Pseudo-Obstruction In Trauma Patients – Part I

A funny thing happened eight years ago. During one of our morbidity and mortality conferences at Regions Hospital, we got the first hint of an emerging pattern. We noted occasional trauma patients who developed colonic pseudo-obstruction (CPO), also known as Ogilvie’s syndrome.

In reviewing our experience, it seemed to occur mostly in men who had sustained pelvic or thoracolumbar spine injuries. Surgical instrumentation for these injuries also appeared to be a common factor, as was middle-aged or older, obesity, and metabolic diseases like type II diabetes.

We continued to see the pattern and treated it in a highly variable way depending on the attending surgeon. Abdominal x-rays were obtained semi-randomly, and if the cecum was considered as the ill-defined term “large,” the patient was sent to the ICU for an injection of neostigmine or endoscopic evacuation. If a perforation occurred, patients often got very sick.

As always, variable practice patterns are fodder for developing a practice guideline. This is the first part of a two-part series on CPO in trauma patients. First, I’ll review a new article describing this condition’s incidence in orthopedic patients. Then, in my next post, I will share a practice guideline we developed for use at Regions Hospital.

The paper was a retrospective cohort study performed by the surgical group at Copenhagen University Hospital in Denmark. They focused on patients who underwent pelvic or acetabular procedures for traumatic injury over twelve years. One cohort consisted of patients who developed CPO; the other did not.

The definition of CPO was based on standard procedures that this surgical group already used, although the specifics were not fully explained. It was based on a physical examination of the abdomen, laboratory tests, and radiographic images. Patients with a colonic diameter >10 cm were treated with neostigmine infusion. Colonoscopic decompression was used if neostigmine did not work or was contraindicated.

Here are the factoids:

  • Of 1060 patients who underwent pelvic or acetabular procedures for trauma, 25 developed CPO (2.4%)
  • The incidence was only 1.6% for pelvic fractures and about 2.6% for acetabular fractures or combined fracture patterns
  • Risk factors identified included motorcycle crash, preperitoneal packing, concomitant skull fracture or intracranial hemorrhage, paraplegia or tetraplegia, internal fixation, congestive heart failure, diabetes, and sepsis or nosocomial infection
  • CPO development increased ICU length of stay by 9 days and added a month to the hospital stay
  • Mortality was higher in the CPO group (8% vs. 6%), but this was not statistically significant

Bottom line: This is the first paper I’m aware of that quantifies what I have already seen regarding Ogilvie’s syndrome in trauma. It should be an eye-opener for everyone who sees seriously injured orthopedic patients. The increased lengths of stay are enormous, which adds to the cost and the potential for even more complications.

Obviously, this is a problem that needs to be taken very seriously. Use of the ICU for neostigmine infusion or procedural decompression should be common. But recognition and initial management should be standardized, so all appropriate patients are treated for the condition.

In my next post, I’ll share the practice guideline we developed at Regions hospital. It is designed to identify the condition early and provide decompressive therapy without moving the patient to the ICU.

Reference: Ogilvie Syndrome in Patients With Traumatic Pelvic and/or
Acetabular Fractures: A Retrospective Cohort Study. J Orthop Trauma 37(3):122-129, 2023.

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