Tag Archives: spleen

Overwhelming Post-Splenectomy Infection (OPSI)

November 6, 2019 The Trauma Pro Leave a comment

Most trauma professionals have heard of OPSI, but few have ever seen it. The condition was first described in splenectomized children in 1952. Soon after, it was recognized that this infection occurred in asplenic adults as well.

OPSI is principally due to infection by encapsulated organisms, those with a special polysaccharide layer outside of the bacterial wall. This layer is only weakly immunogenic, and confers protection from the normal immune mechanisms, particularly phagocytosis. However, these bacteria are more easily identified and removed in the spleen.

OPSI may be caused by a number of organisms, the most common being Strep. pneumonia, Haemophilus influenza, and meningococcus. For this reason, the standard of care has been to administer vaccines targeting the usual organisms to patients who have lost their spleen.

How common is OPSI? A recent paper from Gernany reviewed comprehensive data from 173 intensive care units over a 2-year period. Here are some of the more interesting factoids:

2,859 ICU beds were screened, but the number of unique patients was not given. This is very disappointing because incidence cannot be calculated!
52 cases of OPSI occurred
Only half of the patients had received vaccines
Pneumococcus was the most common bacterium (42%). There were no H. Flu or meningococcal infections.

Bottom line: Yes, OPSI exists and can occur in your asplenic patients. It is uncommon enough that you and your colleagues will probably never see a case. But proper vaccination remains important. Papers consistently show that we are collectively not very good at ensuring that our splenectomized patients receive all their vaccines, ranging from only 11-50%. We collectively need to make better efforts to provide them to our at-risk patients.

Reference: Overwhelming Postsplenectomy Infection: A Prospective Multicenter Cohort Study. Clin Infec Diseases 62:871-878, 2016.

Abdomen, Abstracts

AAST 2019 #3: Delayed Splenectomy In Pediatric Splenic Injury

September 9, 2019 The Trauma Pro Leave a comment

Nonoperative management of the blunt injured spleen is now routine in patients who are hemodynamically and have no evidence of other significant intra-abdominal injury. The trauma group at the University of Arizona – Tucson scrutinized the failure rate of this procedure in children because it is not yet well established.

They reviewed 5 years of data from the National Readmission Database. This is actually a collection of software and databases maintained by the federal government that seeks to provide information on a difficult to track patient group: those readmitted to hospitals after their initial event.

Patients who had sustained an isolated spleen injury who were less than 18 years old and who had either nonoperative management (NOM), angioembolization (AE), or splenectomy were analyzed. Outcome measures included readmission rate, blood transfusion, and delayed splenectomy. Common statistical techniques were used to analyze the data.

Here are the factoids:

About 9500 patients were included, with an average age of 14
Most (77%) underwent NOM, 16% had splenectomy, and 7% had AE (no combo therapies?)
Significantly more patients with high grade injury (4-5) had splenectomy or AE than did the NOM patients (as would be expected)
A total of 6% of patients were readmitted within 6 months of their initial injury: 12% of NOM *, 8% of AE *, and 5% of those with splenectomy (* = statistically significant)
The NOM and AE patients were also more likely to receive blood transfusions during their first admission
Delayed splenectomy occurred in 15% of cases (7% NOM and 5% AE) (these numbers don’t add up, see below)
Statistical analysis showed that delayed splenectomy was predicted by high grade injury (of course), blood transfusion (yes), and nonoperative management (huh?)
In patients who were readmitted and splenectomized, it occurred after an average of 14 days for the NOM group and 58 days for AE (huh?)

The authors concluded that “one in seven children had failure of conservative management and underwent delayed splenectomy within 6 months of discharge.” They stated that NOM and AE demonstrated only a temporary benefit and that we need to be better about selecting patients for nonoperative management.

Hmm, there are several loose ends here. First, what is the quality of the study group? Was it possible to determine if these patients had been treated in a trauma center? A pediatric vs adult trauma center? We know that there are outcome disparities in spleen trauma care at different types of trauma centers.

Next, are they really pediatric patients? Probably not, since age < 18 were included and the average age was 14. Injured spleens in pre-pubescent children behave much better than adolescents, which are more adult-like.

And what about the inherent bias in the “readmission data set?” You are looking only at patients who were readmitted! By definition, youare looking at a dataset of poorer outcomes. What if you had identified 9,500 initial patient admissions from trauma registries and then tried to find them in the readmission set. I know it’s not possible to do that, but if it were I would bet the readmission and delayed splenectomy numbers would be far, far lower.

And what about those delayed splenectomy numbers? I can’t get the percentages to match up. If 15% of the 7965 patients who didn’t have an initial splenectomy had it done later, how does 7.2% of the 7318 NOM patients and 5.3% of the 1541 AE patients add up?

Bottom line: The usual success rate tossed around for well-selected nonoperative management is around 93% when optional adjunctive AE is part of the algorithm. That’s a 1 in 14 failure rate, and it generally occurs during the initial hospitalization. In my experience, readmissions are very rare. And that’s for adults; children tend to behave even better!

I wouldn’t consider changing my practice yet based on these findings, but the devil will probably be in the details!

Here are some questions for the presenter and authors:

Please provide some detail on the data set. We really need to know an age breakdown and the types of centers they were treated at, if available.
Discuss the potential data set bias working backwards from a database that includes only readmitted patients.
Please clarify the delayed splenectomy statistics to help match up the numbers.

I’m anticipating a great presentation at the meeting!

Reference: Delayed splenectomy in pediatric splenic injuries: is conservative management overused? AAST 2019 Oral abstract #8.

Guidelines

Solid Organ Injury Practice Guideline Updated

April 16, 2019 The Trauma Pro Leave a comment

Regions Hospital developed a clinical practice guideline for solid organ management in 2002-2003. It has been revised a few times over the years, as any good guideline should with the availability of new data.

I’ve just put the finishing touches on the latest revision as a result of the updated organ scaling rules published by the American Association for the Surgery of Trauma. I reviewed the new scales for both liver and spleen earlier this year (links below). In the previous iteration of the scaling system, the importance of contrast pooling (pseudoaneurysm) or extravasation beyond the organ was not well defined.

The new guideline explicitly includes these injuries in the high grade group, which for us is grade IV or V. Technically, pseudoaneurysm of the liver is only grade III, but in my opinion demands angiographic investigation and embolism. Thus the inclusion in the high grade / angiography arm of our guideline.

For those of you who have not seen this guideline before, there are several important directives that are listed on the left side of the page:

Patients are NOT made NPO
They do NOT have activity restrictions (such as bed rest)
Serial hemoglins are NOT drawn
An abdominal CT scan is NOT repeated

These changes were made in 2015 based on our clinical experience that properly selected patients almost never fail. And they still don’t, so why starve, restrain, poke, and re-irradiate them?

Additionally, we included explicit impact activity restrictions for post-discharge so that patients would get the same message from all members of our team.

Click the image below to download the guideline and have a look. I’m interested in your comments!

Related posts:

Solid organ

APSA Activity Restrictions After Solid Organ Injury: Aren’t We Done With That Yet?

November 1, 2018 The Trauma Pro Leave a comment

Nearly 20 years ago, the American Pediatric Surgical Association (APSA) published a clinical guideline for management of solid organ injury in children. Part of the guideline included activity restrictions, specifically for a period of time after injury. This was generalized by many clinicians to include a period of in-hospital bed rest.

A paper has just been published that examines the usefulness of restricting activity in pediatric patients with solid organ injury. It was authored by a consortium of 10 Level I pediatric trauma centers, and included all patients through age 18 who did not have a concomitant significant renal injury and no pancreatic injury. All injuries were diagnosed by CT scan over a 33 month period.

Activity restrictions were given to all patients upon discharge, which limited sports, wheeled recreational activities, and anything else requiring two feet off the ground. A phone survey was conducted 60 days post-discharge to judge compliance. Unplanned return to ED, readmission, and complications were also assessed.

Here are the factoids:

A total of 1007 patients were studied, and 99 were excluded due to concomitant pancreatic or high grade renal injury. An additional 79 were excluded due to missing injury grade or operative management.
Of the remaining patients, only 366 were available for 60-day followup
279 claimed to adhere to activity restrictions; 13% returned to the ED and 6% were readmitted.
49 admitted that they did not pay attention to the restrictions, and only 4 (8%) returned to the ED. None were hospitalized.
Even in the high-grade injury patients, there was no difference between compliant or noncompliant groups
No patient in either group bled post-discharge

Bottom line: Due to the nature of this study (specifically the phone survey component), there will be degradation of the data. Some patients do not want to admit that they didn’t follow the doctor’s orders. In theory, this could increase the number of complications / returns to ED in the “compliant” group. But it did not.

The other issue I have with this study is that it was not stratified by age. The spleen of an 18 year old is very different than that of a 6 year old. Sixty years ago, we used to take spleens out in adults with a diagnosed injury. The reason we moved toward nonoperative management in adults was the very favorable experience we had in children. Unfortunately, nowhere in this paper is age broken out. Typically, the number of older children (who are really adults) with the injury far outnumber the younger ones, which also tends to increase the number of complications seen. But once again, we did not. Small numbers? Possibly.

So what are we to make of all this? Basically, it tells us that we’ve been trying to restrict activity in our patients with liver and spleen injury for no good reason. And this applies especially to the children. Look at your own clinical experience, and try to recount how many “failures” you’ve seen due to failure to follow activity restrictions. More typically, failures are due to undiagnosed or untreated pseudoaneurysms.

It’s time to rethink your solid organ management protocol, if you haven’t already. Do you really need a period of NPO status? Or bedrest? Or activity restriction? And have you ever tried to restrict activity in a 6-year old? Have a look at the guideline we’ve used at my hospital for nearly 20 years! We got rid of the NPO and bedrest restrictions a while ago. Now it’s time to start reducing the activity restrictions!

References:

Evidence-Based Guidelines for Resource Utilization in Children With
Isolated Spleen or Liver Injury. J Ped Surg 35(2):164-169, 2000.
Adherence to APSA activity restriction guidelines and 60-day clinical outcomes for pediatric blunt liver and splenic injuries (BLSI). J Ped Surg in Press, 2018.

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