Monday, February 19, 2018

Perforated appendix not seen on CT scan

From an email received two days ago. Posted with permission and edited for length and clarity.

I came across your blog while looking for information on something puzzling that happened to my sister. I read the blog on CT scans and appendicitis* and went through all of the comments section. I couldn't find a case like my sister’s.

She has been sick off and on for the last two months. It began with what seemed like a bad stomach virus, fever, throwing up, diarrhea, gas pain, bloating, and stomach cramps. She brushed it off as a 24 hour type thing, stayed home from work a few days, and felt better but never returned to normal. She would have intermittent stomach upset and began to have weight loss. About 3 weeks ago, she went to see her GP who ran some tests (antibody tests, no CBC, chem 7 or normal work up) and diagnosed her with gluten intolerance.

She changed her diet (no gluten), but one week ago, the massive cramps, vomiting, fever, diarrhea came back sending her to the ER. They found she was severely dehydrated with a dangerously low potassium level. Her hemoglobin was 6 (they had to give her blood), and her white blood cell count was through the roof! A CT scan showed what looked like inflammation in her abdomen and two masses near her ovary, one 12 cm the other 14cm. She was admitted to the ICU. Broad spectrum antibiotics were given and blood cultures came back positive for bacteria usually found in the bowel. After a few days on antibiotics, radiology drained the abscesses and removed 280 mL of pus.

At this point, she seemed to recover. The abscess fluid grew the same bacteria as the blood culture. The doctors weren't sure what the origin of the infection was, but suggested Crohn’s or IBS.

She again spiked a temp. While having her drains irrigated, the tech saw more abscesses. She was scheduled for open surgery the next morning as they suspected a hole in the bowel. Two days ago, the surgery was performed, and a ruptured appendix was found. We were surprised the ruptured appendix had not been seen on the CT performed at the ER on night 1. They have since scanned her twice, and even after the surgery, they found more abscesses on her left side near her ovary. She had another drainage procedure this morning where two drains had to be inserted, because there was infection in the ovary as well. They are now confident all the infection has been cleared.

I can't get past two things. The GP not doing standard bloodwork 3 weeks ago. More importantly, how does a ruptured appendix not show up on a CT scan? I read your blog and the conventional wisdom you expressed was if you can't see the appendix on a CT there is no appendicitis. I cannot find a case like my sister’s as of yet. She is in a hospital bed with a vertical cut, drainage tubes, an NG tube, IVs, and just exhausted from this whole situation. I have great respect for the medical profession. My own children's lives were saved by an incredible world class OB, my oldest daughter is premed and just took the MCAT. I understand doctors are not God and are human, but I'm stunned that a ruptured appendix was missed on a CT scan.

Have you seen or heard of this before?

That is quite a story. Thank you for bringing it to my attention.

I can only assume that the first CT scan did not show an appendix because it was probably already perforated. Due to the surrounding inflammation, it may have been unrecognizable as the appendix on the scan.

I have seen cases like this before. Your sister’s experience reinforces the point that even in the era of sophisticated imaging, appendicitis can be very difficult to diagnosis.

Regarding the GP not doing bloodwork, be aware that appendicitis cannot be diagnosed by bloodwork alone. An elevated white blood cell count is a nonspecific finding. Even if the GP had ordered a CBC, it would not have been definitive.

I already answered your question about why the appendix may not have been seen on the first CT scan. One would have to see the images to be sure, but diagnoses are easier to make in retrospect.

It sounds like your sister has had a rough time. I hope she is better soon.


Korhomme said...

Do we know the position of the appendix in this case?

Skeptical Scalpel said...

Good question. I do not have that information.

RobertL39 said...

Where are the physical exam results??? Was the minimal lab testing initially done informed by a decent abdominal exam, or just by the history? One would think, but obviously not know for sure, that a decent abdominal palpation would have disclosed an obvious problem early on, one which merited a CBC at the very least, perhaps a CRP, and perhaps further evaluation. "Never returned to normal" "intermittent stomach upset and weight loss" should have led to a more comprehensive evaluation than 'antibody tests'. Is this another story of too much attention to data and not enough to the patient?

Skeptical Scalpel said...

Good points. I don't know what the physical exam, if it was done, showed. If, as Korhomme implies, the appendix was retrocecal, physical exam may not have been impressive. I'm not a fan of CBCs for this diagnosis.

Korhomme said...

As you know, Skepto, I'm a fan of Zachary Cope and his book on the Acute Abdomen. He describes, IIRC, the seven positions of the appendix. While we're all familiar with the "typical" presentation, some of the other positions do modify the symptoms and the signs. A retro-ileal appendix is associated with more vomiting than is "usual"; both it and a retro-caecal appendix may not show much in the way of local tenderness which is the 'cardinal' sign of appendicitis.

I was wondering if this patient had had a pelvic appendix. Here, back in the day, as this was associated with vomiting and diarrhoea, such patients were then admitted to a 'fever hospital' with suspected gastroenteritis. It was only when they developed peritonism, rising up from the pelvis, that the penny dropped. There is no abdominal tenderness in early pelvic appendicitis; the local tenderness is found on rectal examination. But you know that; alas, I suspect that our juniors, more used to 'scan first, think later' don't.

Skeptical Scalpel said...

Thanks for the explanation. If anyone is still reading books, the 22nd edition of Cope's "Early Diagnosis of the Acute Abdomen" (2010) is still being sold [].

Korhomme said...

Another question — and if I seem to be hogging the comments, my apologies. There is no reference to antibiotics before the patient was in hospital. Do we know whether any were prescribed in this time?

Antonio said...

as i tweeted yoour post... it is very diffcult for this to happen, if we only trust our hands, rather than a CT scan to solve a diagnosis. a perforated appendix has unequivocal symptoms at the physical exam, they are well described in the literature, some cases yes, are very difficult to diagnose... but ultimately a late diagnosis cant explain how a surgeon can miss a "surgical abdomen"

Skeptical Scalpel said...

I do not believe she was given antibiotics before she was admitted to the hospital.

Skeptical Scalpel said...

Antonio, I saw your tweet. Here's how I responded:

I'm sorry, but I must disagree. I was trained in the era before CT scans and ultrasounds were invented or routinely used. We misdiagnosed perforated appendicitis back then too, probably more often than we do now.

RobertL39 said...

I agree that physical exam may not have been impressive, but also probably not normal. It would *probably* have shown more than what one would expect with the proffered diagnosis of gluten sensitivity. I agree the CBC is not a great tool here, but do you really think it would have been normal if the appendix was indeed perforated at that first visit, as it seems like it was? How often is the CBC normal in a perforated appendix? If the exam were somewhat abnormal and the CBC even slightly abnormal I expect a bit more investigation might have been done. But we'll never know.

Antonio said...

im not saying that CT scans are over rated, in fact they have change the way of doing medicine... all im saying is that i've seen a lot of practicians depending too much on ct scans, MRI and ultrasound. just yesterday i was oncall... i want to share this case with you:

its about a 34 years old females, 24 hours of abdominal pain on the upper right cuadrant, an ultrasound was made and found gallstones, so she was treated as a biliary colic... white blood cells 15.8 gran% 85 ... tenderness was present , fever and nausea... neither of those related to a biliary colic... cholecystitis probably?? no murphy on the physical exam. one thing that caught my atention was that the tenderness also was present in the right lower cuadrant... we decided to go to the operating room... a flegmonouse appendix retrocecal subhepatic...

this cases are very interesting, and thanks for sharing on your blog doctor.. ima big fan!!

cheers from venezuela!

Skeptical Scalpel said...

ROBERT, I didn't say I thought the CBC would have been normal. I said an elevated WBC does not necessarily mean the patient has appendicitis What other investigation would have been done?

Antonio. I hope you are doing well in Venezuela. I know things are difficult there.

Anonymous said...

This scenario is not unheard of. In fact, quite typical of the complications of an untreated ruptured appendicitis. I assume the writer resides in England or Canada (based on reference of family doctor as GP). An otherwise healthy woman with appendicitis that subsequently ruptured. Her own body was able to walled off the inflammation and subsequently it turned into a phlegmon and then an abscess. This chronic inflammation was not bad enough to cause her to be seriously ill, but just indolent enough to cause generalized malaise. It also would explain the elevated white count (a self-limited inflammatory process/abscess on the way to spontaneous resolution would have had a "normal" white count).

For some unknown reason her body was subsequently not able to "contain" the inflammation and led to the first ED visit, where the CT scan found an abscess. At this stage it would be AMAZING to find a ruptured appendix as often time its simply obliterated. This said abscess was drained by IR, treated with antibiotics and bowel rest (appropriate treatment given lack of generalized peritonitis). Sounds like she did not respond well to this conservative management and therefore required open surgery, where the definitive diagnosis of ruptured appendicitis was finally made. As part of the surgery a typical thorough washout of the peritoneal cavity was done. For a class 4 contaminated case like that, it's no surprise she developed subsequent pelvic and likely interloop bowel abscess. These again required drainage by IR. Patient is actually fortunate that they are able to technically do so.

My own observations:

-A simple CT scan upfront by the family doctor/GP would have shaved much time off the diagnosis of abscess and allowed earlier treatment. Is this a case of over-aversion to CT scans for financial/radiation-exposure/old-school-over-reliance-on-physical-exam-syndrome?

-cases and complications like this affirms my belief that acute appendicitis IS a surgical disease, definitively addressed by appendectomy (as opposed to antibiotic medical therapy that's currently in vogue)

Skeptical Scalpel said...

Anonymous, thank you for your input. The case took place in the US. I agree a CT scan early in the course of this illness would have saved the patient a lot of trouble, and I agree that too much has been made of potential radiation exposure from CT scans. Instead of one diagnostic CT scan in the beginning, this patient has had several.

In 2016, a radiologist and I blogged about some misconceptions regarding radiation and CT scanning. Here is the link to that post

I also agree that appendicitis is a surgical disease as this case clearly illustrates.

artiger said...

Scalpel, there will still be proponents of antibiotic treatment of appendicitis, and those of us on the surgical side will still point to higher success rates and definitive treatment with surgery (especially laparoscopic). If all patients with appendicitis were informed of this case as a possible outcome (without surgical intervention), I wonder how many would still choose to avoid surgery.

I had a case a year or so ago that was a little similar, except the patient had a CT scan that showed a phlegmonous process in the lower central abdomen, and she had been somewhat ill off and on for a while. It was initially thought to be advanced diverticulitis, and when a F/U scan a few days later looked a little worse, I saw her, and we decided to proceed with laparotomy, where a ruptured appendix was found, with sigmoid colon and small bowel surrounding it. Nothing on CT ever suggested a ruptured appendix. It does happen.

Skeptical Scalpel said...

Artiger, as you know, appendicitis presents in many forms. A lawyer once said to me, "Why do you surgeons have so much trouble diagnosing appendicitis?" He had read about it and it seemed so simple to him. I replied, "The patients don't read the book."

Anonymous said...

You can't understand two things completely entire your life, no matter how experienced you are: women and presentation of Appendicitis. Cheers

Skeptical Scalpel said...

Anon, well put.

artiger said...

Careful, y'all, there is a MeToo movement going on.

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