Category Archives: Abdomen

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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Nonoperative Management Of Abdominal Stab Wounds: The Practice Guideline!

In my previous post, I reviewed a new paper that examined the appropriate amount of time that patients should be observed for nonoperative manage of an abdominal stab wound. Many of you know that I am a fanatic of properly crafted clinical practice guidelines (CPG). I decided to make a first pass at converting the LAC+USC group’s paper to something that will be helpful at the bedside.

This CPG incorporates the patient selection and timing information published in the paper. It breaks the process down into easily followed tasks, and fills in the blanks for shift to shift management. The CPG is displayed in an “if this, then do that” format. This firms up decision making and makes it easier for your trauma program to monitor compliance with it.

A note about CPGs: they generally cover about 90% of clinical cases. Obviously, they cannot provide guidance for certain rare combinations of circumstance. In that case, the trauma professional should do what they think is right for that situation. Most importantly, they should document this rationale in a progress note.

Here are answers to some of your questions in advance:

  • Patients should not be kept at bed rest. This is always bad.
  • There is no reason to keep the patient NPO. A very small percentage of patients actually fail. It makes no sense to starve everybody for the one or two patients that need to go to the OR each year. Anesthesiologists at trauma centers are very skilled at providing safe intubation in all patients. As you all know, every trauma activation patient coming into your trauma bay needing intubation has just finished a seven course meal!
  • Give your patient clear discharge instructions! They need to know what they can do, and what to look for if things eventually go awry.

And please leave comments and suggestions for improvements in the reply box below or by email to [email protected] There are always ways to make CPGs even better! I have also included a Microsoft Publisher file so you can modify this guideline to better suit your trauma center.

In my next post, I’ll publish the serial abdominal observation CPG I mention in this one.

Resources:

  1. Download a pdf file of the guideline
  2. Download a Publisher file of the guideline

 

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Nonoperative Management Of Abdominal Stabs: How Long Should We Watch?

Gunshots to the abdomen are a no-brainer that nearly always require operative exploration, but stab wounds are more challenging. They are low velocity, and injury only occurs in the pathway of the knife. It is more likely that inconsequential (or no) injuries occurred. Since exploratory laparotomy (or even laparoscopy) is not a benign procedure, trauma professionals frequently opt for selective nonoperative management (observation) in these cases.

What does observation mean? The patients are kept in the hospital for a set period of time, receive serial abdominal examinations, and get a few repeat lab tests. If the exam changes, the patient is taken to the OR to find out why. If it doesn’t, they are fed and sent home.

But what is the appropriate period of time to observe? One major concern is for the possible hollow viscus injury. Stomach and colon contain fluids that cause prompt peritonitis. But small intestinal content is rather innocuous, with neutral pH, normal concentration, and few bacteria. Peritonitis may not occur for days. Yet most centers send these patients home within 12 to 24 hours of injury.

What is the right answer? The trauma group at LAC+USC in Los Angeles performed a prospective, observational study to try to answer the question. They enrolled all patients with abdominal stab wounds presenting to their center over a three year period. They were generous (and correct) with their definition of the abdomen, including the thoracoabdominal portion up to the 5th intercostal spaces, and the pelvis.

Patients were excluded if they were hemodynamically unstable, or had an evisceration or obvious peritonitis. Most patients received a CT scan, and patients with suspected hollow viscus injury were excluded from the study and taken to the OR. All others were observed in a dedicated unit and were monitored for change in exam, need for blood transfusion, or other event which was recorded for the study.

Here are the factoids:

  • A total of 256 patients met study criteria: 77% had a single stab and 76% had a negative FAST exam
  • There were 46 patients who underwent immediate laparotomy for evisceration (59%), hemodynamic instability (33%), or peritonitis (24%)
  • 81% of patients underwent CT scan, and 13% were taken to OR based on the findings
  • This left 210 patients for nonoperative management
  • Of these, 71 had positive scans and all were due to solid organ injury. One patient failed at 32 hours due to increasing lactate and WBC, but the operation was nontherapeutic.
  • Another 14 patients had equivocal CT findings and two failed at 10 and 20 hours due to small bowel injury discovered by increasing lactate, WBC, change in exam, and air on a repeat CT
  • All 123 patients with negative scans passed nonoperative management
  • Median hospital length of stay was 3 with a range of 2-6 days

Since all of their patients who failed observation did so within 24 hours, the authors recommended a 24 hour observation period for all patients with stabs to the abdomen who did not meet their exclusion criteria.

Bottom line: Trauma professionals have needed a study like this for decades. Until now, we’ve been flying by the seat of our pants, with each surgeon making up his or her own magic number. This is a well done first attempt at defining what that number should be. 

Yes, there are some limitations to the study. The most important one that we don’t know the answer to is how many patients were successfully discharged that presented to another hospital with complications or failure. But this study provides a very reasonable estimate that helps us balance the cost (and patient inconvenience) of time in the hospital vs the dangers of a delayed diagnosis.

The only thing that remains is to design the practice guideline that incorporates the observation period, how often serial exams and labs should be obtained, and when the CT should be repeated.

Reference: Prospective evaluation of the selective nonoperative management of abdominal stab wounds: When is it safe to discharge? Journal of Trauma and Acute Care Surgery: November 2022 – Volume 93 – Issue 5 – p 639-643.

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Trauma And The Gut Microbiome

This is a follow-on post from one published last week (gut microbiome changes in rats due to trauma). Click here to read it.

One of the newest frontiers in health-related research recognizes the importance of the human microbiome. This term describes the collection of all genomes from the microorganisms found in a particular environment, such as in, on, or around a human. The term microbiota refers to the specific bacteria, viruses, and fungi that colonize the areas within this environment.

Within the last decade or so, we have just begun to appreciate the importance of the microorganisms that live within us. From a purely numerical standpoint, there are 10 times as many of them as there are our own human cells. However, since they are so small in comparison, we can’t really appreciate the huge number of “other” cells in and on us.

These tiny cohabitants provide many, many functions that are important to our health and well-being. They protect us from pathogenic organisms, help digest our food, fine-tune our immune system, and synthesize proteins, amino acids, and vitamins that are essential to our health. And much more!

The usual microbiota can be disrupted by disease, poor diet, stress, and even a single dose of antibiotics. With each new research paper, we recognize new functions for and disruptors of our microbiota.

The surgery groups at two San Antonio hospitals, UT Health and the US Army Institute of Surgical Research, recognize the importance of the gut microbiota, building upon prior work demonstrating changes within it in the presence of trauma and burn injury.

The authors performed a prospective, observational cohort study of severely injured patients over a two-year period. They attempted to characterize differences in the microbiota between trauma patients and to identify changes in these communities over time.

A rectal swab was obtained from each patient shortly after admission and the microbial DNA present was identified. This was repeated regularly throughout the hospital stay.

Here are the factoids:

  • 72 patients and 13 healthy controls were enrolled
  • Patients were severely injured with a mean ISS of 21; an average of 6 units of blood products were given in the first 24 hours
  • Only one fourth of the injured patients had a microbiome similar to the healthy controls
  • These 26% received significantly more blood products than the dissimilar patients (14 units vs 3)
  • There were significant decreases in the numbers and ratios of normal gut bacteria and increases in the numbers of pathogenic bacteria. These changes increased with time in hospital

Bottom line: Yes, this is new and bizarre territory. It appears that shock, hypoxia, medications (and not just antibiotics), surgical intervention, and poor nutrition can adversely affect the microflora in our gut. Conversely, early transfusion seems to ameliorate this effect to some degree.

At this point in time, there is nothing you can do with this knowledge. Just be aware that everything you routinely do to your patients can change their microbiota, and this may in turn have unexpected effects on their health and recovery. I anticipate seeing many more papers like this one in the near future.

Reference: A prospective study in severely injured patients reveals an altered gut microbiome is associated with transfusion volume. J Trauma 86(4):573-582, 2019.

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