June, 2010
Charles A. Pilcher MD FACEP
Appendicitis is the most common acute abdominal surgical condition in medicine, yet there is probably not a single physician in practice today who hasn’t missed the diagnosis at least once. Often that results in “simple” appendicitis becoming a “ruptured” or “perforated” appendix. I have reviewed several such cases which have prompted this review.
The appendix is a tubular extension (about 1 cm diameter x 6 cm long) of the cecum, in the right lower quadrant of the abdomen at the beginning of the colon or large bowel. Because of its structure, it acts as a “catch basin” or blind pouch where a variety of bacteria and mechanical obstructions can cause problems. One can think of appendicitis as a boil or abscess. Germs get in, propagate, and cause an infection. If the infected appendix is not removed, it can swell to the point where pressure causes rupture, spilling the infection into the abdominal cavity.
Diagnosing appendicitis is easy – when it presents in classical, textbook fashion, which occurs in only about 50% of patients. The typical symptoms are:
- A sense of being ill
- Generalized abdominal discomfort
- Loss of appetite
- Nausea
- Pain in the right lower quadrant of the abdomen
- Fever
- Vomiting
Classically these symptoms appear over a period of about 24 hours in the order listed. Combined with tenderness in the right lower quadrant of the abdomen on examination, further testing rarely changes the diagnosis or alters the treatment, especially in children.
But when 50% of patients with appendicitis “don’t follow the rules,” the diagnosis remains one of the most commonly missed in medicine. Nationally, about 30% of appendicitis cases progress to perforation (14.4% in Washington State) before the diagnosis is made. Sometimes that is because of delay on the part of patients in seeking medical care, and other times it is because the patient’s symptoms do not suggest to the physician a “surgical abdomen.” If the problem has not progressed to the point where surgery is considered a reasonable option at the time of first evaluation, regardless of the diagnosis, “watchful waiting” is often the best option. The reason for that is that there is still no “gold standard” for the diagnosis. CT scans, nowadays considered our most accurate study, still fail us, leading to both missed diagnoses and unnecessary operations in between 5% and 10% of cases. The scans themselves are known to increase the risk, though marginally, of abdominal cancer in later life.
Clearly, once the diagnosis is made, surgical removal of the appendix is the treatment of choice. That said, there are numerous reported cases where non-operative management has been successful, or where a “healed appendix” was diagnosed at a subsequent surgical procedure. This shows that it’s not just that the diagnosis that can be obscure, but that the treatment is not as well-defined as we might think.
Below is [was] an algorithm by Santacroce and Ochoa from their chapter on appendicitis in Sabiston Textbook of Surgery. [It has been lost in 7 years of updates of WordPress but still exists in Sabiston’s textbook./cp]
Figure 49-3 Algorithm for the evaluation and management of patients with possible acute appendicitis based on surgical assessment of clinical probability of the diagnosis.
The key question any physician faced with a patient with abdominal pain must first ask is, “Does this patient have a potentially surgical abdomen?” If so, a full court press to define the cause – whether that is appendicitis or something else – is urgent. If at the time of examination a “surgical abdomen” is not present – in other words, regardless of the diagnosis, surgery is not immediately indicated – a physician may reasonably elect to postpone further studies.
However, choosing that pathway comes with added responsibility on the part of both patient and physician. The physician must inform the patient of the possible causes of the problem, almost always including appendicitis in the list, and warn the patient of the symptoms that would warrant re-evaluation, and within what time frame. Since the classic symptoms of appendicitis develop over a period of about 24-48 hours before rupture, time is a key component of the physician’s advice.
When some 30% of appendices are ruptured at the time of surgery, and 50% of patients present with atypical symptoms, missing the diagnosis of appendicitis is not uncommon. However, if the medical record reveals classical findings and the diagnosis was missed, care is likely to be found to be substandard. The reality, though, is that any time the diagnosis is missed, the medical record is likely to include few if any classic findings. The fact that a physician has even thought of appendicitis, yet classifies the patient as low risk, can be a valid defense, and the chart will usually support the physician’s impression. A good follow-up plan remains mandatory for all such abdominal complaints.
Although morbidity can triple (from 1% to 3%) when the appendix ruptures, fortunately for the patient the impact is rarely more than a few extra days in the hospital, a slightly higher cost, and a scar that might have been avoided if diagnosis had been made earlier and a laparoscopic appendectomy could have been done. Because of these factors, demonstrating that a physician’s care has been below acceptable standards can be an uphill climb with relatively little return for an unhappy patient and his/her attorney.
The likelihood of a successful claim increases in the following situations:
- The chief complaint on admission is “abdominal pain,” not vomiting, diarrhea, etc.
- The history fails to document the characteristics of any pain that is mentioned.
- The exam fails to document the absence of tenderness and/or rebound, especially in the right lower quadrant.
- A diagnosis of “gastroenteritis” was made in the absence of nausea, vomiting and/or diarrhea.
- Narcotics were prescribed for control of pain.
- Appendicitis is never mentioned as a possible cause of the pain.
Other factors such as rectal exam, blood tests, ultrasound, CT scans, etc. are far less important than the above history and exam elements.
As summarized by Dr. Benson Yeh in an article on “evidence based medicine,” “Appendicitis will continue to be a diagnosis that calls for a composite approach that integrates all available factors and uses clinical judgment to determine the need for further imaging.” (Annals of Emergency Medicine. 52:301-303, Sep 2008.)
For further information:
- Missed appendicitis and medical liability. Reynolds SL. Clin Ped Emerg Med. 2003 4:231-234,
- The risk of appendiceal rupture based on hospital admission source. Buckley RG et al. Acad Emerg Med. 1999 Jun;6(6):596-601.
- Hospital- and patient-level characteristics and the risk of appendiceal rupture and negative appendectomy in children. Ponsky TA et al. JAMA. 2004 Oct 27;292(16):1977-82.
- Appendicitis. Santacroce L and Ochoa J in Sabiston Textbook of Surgery, 18th ed. 2007