Moshe Schein
Believe nobody – question everything
“To open an abdomen and search for a lesion as lightly as one would open a bureau drawer to look for the laundry, may mean lack of mental overwork to the surgeon, but it means horror to the patient.” (J. Chalmers Da Costa, 1863–1933)
When treating a patient with acute abdominal pain it is tempting to make extensive use of ancillary investigations. This leads to the emergence of “routines”
in the emergency room (ER) whereby every patient with acute abdominal pain undergoes a plain X-ray of the abdomen (AXR) and a series of blood tests, which typically include a complete blood count, routine blood chemistry and serum amylase. These “routine” tests have a very low diagnostic yield and are not cost- effective. However, they are also an unavoidable part of life in the ER and are often obtained before the surgical consultation.
For the vast majority of patients who on examination have a clear-cut diffuse peritonitis no imaging is necessary because a laparotomy is indicated. But what appears clear cut to the experienced surgeon may be less so for you. Bear in mind the following caveats:
Intestinal distension, associated with obstruction or inflammation (e.g., enteritis or colitis) may produce diffuse abdominal tenderness – mimicking
“peritonitis”. The “whole” clinical picture as well as the AXR will guide you toward the proper diagnosis (> Chaps. 21 and 25).
Acute pancreatitismay present with clinical acute peritonitis. You should obtain, therefore, a serum amylase level in order to avoid falling into the not so uncommon trap of unnecessarily operating on acute pancreatitis. (> Chap. 18)
In any patient who receives or has recently received any quantity of antibiotics think about C. difficile enterocolitis, which may present – from the beginning – as an acute abdomen without diarrhea. Here, the optimal initial management is medical and not a laparotomy; bedside sigmoidoscopy and/or computed tomo- graphy (CT) may be diagnostic (> Chap. 24).
* Asher Hirshberg, MD contributed to this chapter in the 1st edition of the book.
Chest X-ray (CXR)
A CXR is routinely obtained to search for free air under the diaphragms,which is demonstrated in the majority of patients with perforated peptic ulcer (> Chap.17) but less frequently when colonic perforation is the underlying problem (> Chap.26).
Remember that free air is better seen on an erect CXR than AXR. Free intra- peritoneal air is not always caused by a perforated viscus and it is not always an indication for a laparotomy. There is a long list of “non-operative” conditions that may produce free intra-peritoneal air, such as a tension pneumothorax or even vigorous cunnilingus (oral sex). So, rather than being dogmatic, look at the whole clinical picture.
Any textbook tells you that lower lobe pneumonia may mimic an acute abdomen, so think about it. Obviously, findings such as lung metastases or pleural effusion may hint at the cause of the abdominal condition and influence treatment and prognosis. Pneumothorax, pnenumomediastinum or pleural effusion may be associated with spontaneous esophageal perforation – Boerhaave’s syndrome
(> Chap. 14), which can present as an acute abdomen. The value of a CXR in blunt
or penetrating abdominal injury is obvious. A pre-operative CXR may also be requested by the anesthesiologists, especially after you have inserted a central venous line, or for no reason at all.
Plain Abdominal X-ray (AXR)
This is the classical surgeon’s X-ray,as only surgeons know how to rely on those simple and cheap radiographs. Radiologists can look and talk about AXRs forever, searching for findings that could justify “additional” imaging studies. We surgeons need only a few seconds to decide whether the AXR is “non-specific”, namely, does not show any obvious abnormality, or shows an abnormal gas pattern or abnormal
“opacities”. Unfortunately, in many of today’s “modern ERs” the humble AXR is bypassed in favor of the high-tech CT. In fact now, for many (but hopefully not for you), the CT supplants AXR as well as proper history taking and physical examina- tion. Do not forget that we operate on patients and not on CT abnormalities. Go
to > Chap. 5 to read about AXR in detail.
Abdominal Ultrasound (US)
Abdominal US is a readily available diagnostic modality in most places. Its reliability is operator dependent; the ideal situation is when the US is performed and interpreted by an experienced clinician – a surgeon. US is very accurate in the
diagnosis of acute cholecystitis (> Chap. 19); it is also used by the gynecologists to rule out acute pelvic pathology in female patients (> Chap. 31), and to demonstrate an acutely obstructed kidney caused by a ureteric stone.A non-compressible tubular structure (a “small sausage”) in the right lower quadrant may be diagnostic of acute appendicitis, but as will be discussed in > Chap. 28 you rarely need abdominal imaging to reach this diagnosis. US is useful in demonstrating intra-abdominal fluid – be it ascites, pus, or blood, localized or diffuse. In blunt abdominal trauma, FAST (focused abdominal sonography for trauma) has emerged as a serious rival to diagnostic peritoneal lavage (> Chap. 35).
Abdominal Computed Tomography
The use of the CT scan in the acute abdomen is not well defined, and remains a subject of some controversy. While it is true that a CT scan should not be part of the management algorithm in most patients with acute abdominal pain, the new spiral CT technology is nevertheless immediately available, very powerful and thus extremely tempting to use, especially by less experienced clinicians.
A case in point is acute diverticulitis (> Chap. 26). Once the clinical pattern of localized peritonitis in the lower left quadrant has been identified, initial manage- ment is conservative. A CT may show the inflammatory process and even a para- colic abscess, but will not distinguish between diverticulitis and a localized per- foration of a colonic tumor.In any case,this will not alter the approach because most surgeons would still opt for a trial of intravenous antibiotics as the initial treatment modality for this clinical pattern (> Chap. 26).
The true role of the CT, where it can really make a critical difference, is with
“clinical puzzles”. Not infrequently, the surgeon encounters a patient with acute abdominal pain that does not fit any of the clinical patterns described in the previous > Chap. 3. The patient is obviously sick, but the diagnosis remains elusive.
Occasionally, there may be a suspicion of acute intra-abdominal pathology in an unconscious patient. Under these unusual circumstances, the CT scan may be very helpful in identifying an intra-abdominal problem. It is even better in excluding the latter by an absolutely normal CT. CT is frequently indicated in patients with blunt abdominal trauma as discussed below (> Chap. 35).
Judicious and selective use of CT may help in avoiding surgery altogether – where previously “negative”or “exploratory”or “non-therapeutic”operations would have been performed. It may suggest that alternative percutaneous treatment is possible and, even if operation is still indicated, CT may dictate the optimal incision and approach (> Chap. 10). CT has a definite role in the post-laparotomy patient as discussed in > Chap. 46. For detailed discussion on the interpretation of ab- dominal CT go to > Chap. 5.
A Word of Caution
For most patients with acute abdominal pain,unnecessary ancillary investiga- tions are merely a resource problem and a waste of time.But for two types of surgical problems, unnecessary imaging is often lethal:
Acute mesenteric ischemiais the only life-threatening abdominal condition that cannot be easily classified into one of the five clinical patterns described in
> Chap. 3. Because of this, and because the window of opportunity to salvage viable
bowel is so narrow, you must have this diagnosis constantly embedded in the back of your mind. The best chance to salvage these patients is to identify the clinical picture of very severe abdominal pain with few objective findings in the appropriate clinical context (> Chap. 23) and to proceed directly to mesenteric angiography.
Needless to say,if the patient has diffuse peritonitis,no imaging is necessary and the next step is an urgent laparotomy. The tragedy in these patients is the inability of even an experienced clinician to make his or her mind up regarding the need for urgent angiography. As a result the patient is sent for a long series of non-relevant imaging studies and the opportunity to salvage viable bowel is lost.
The second condition where the abuse of imaging is often lethal is with a ruptured abdominal aortic aneurysm (AAA)(> Chap. 37). A ruptured AAA may not present as abdominal pain and shock but merely as severe abdominal or back pain, and it may not be easily palpable in an obese patient. When the possibility of a contained rupture is raised in a hemodynamically stable patient, the one and only ancillary investigation that is required is an urgent CT scan of the abdomen.
Unfortunately, too many times these patients spend several hours in the ER, waiting for the results of non-relevant blood tests and progressing slowly along the imaging path from AXRs, which are usually non-diagnostic, to US, which shows the aneurysm but usually cannot diagnose a rupture, to a long wait for unnecessary contrast material to fill the bowel in preparation for a “technically perfect” CT scan.
The tragic consequence of these delays is a dramatic hemodynamic collapse either before or during an abdominal CT scan.
Contrast Studies: Barium vs. Water-soluble Contrast
A caveat: in emergency situations do not use barium! Radiologists prefer barium because of its superior imaging qualities, but for us – surgeons – barium is an enemy. Bacteria love barium, for it protects them from the peritoneal macrophages; a mixture of barium with feces is the best experimental recipe for the production of intractable peritonitis and multiple intra-abdominal abscesses.
Once barium leaks into the peritoneal cavity it is very difficult to get rid of. Barium administered to the gastrointestinal tract from above or below tends to stay there for many days – distorting any subsequent CT or arteriography.
A contrast study in the emergency situation has only two queries to answer:
Is there a leak and, if so, where?
Is there an obstruction and, if so, where?
For these purposes Gastrografin is adequate.Use Gastrografin in upper gastro- intestinal studies to document or exclude gastric outlet obstruction or a Gastro- grafin enema to diagnose colonic obstruction or perforation.Unlike barium,Gastro- grafin is harmless should it leak into the peritoneal cavity. Try to operate on a colon full of barium: a clamp slides off, a stapler misfires and you – not the radiologist – are the one left to clean the mess. Take some advice from our bitter experience:
ordering a Gastrografin study is not enough; you must personally ensure that barium is not used.
Blood Tests
As stated above, “routine labs” are of minimal value. In addition to amylase level the only “routines” that can be supported are white cell count and hematocrit.
Elevated white cell count denotes an inflammatory response.Be aware,however,that you can diagnose acute cholecystitis or acute appendicitis even when the white cell count is within a normal range. Its elevation, however, supports the diagnosis. Low hematocrit in the emergency situation signifies a chronic or subacute anemia; it does not reflect on the magnitude of any acute hemorrhage. Liver function tests are of some value in patients with right upper quadrant pain, diagnosed to have acute cholecystitis (> Chap. 19) or cholangitis (> Chap. 20). Serum albumin on admission is a useful marker of the severity of the acute, or acute-on-chronic disease, and is also of prognostic value. When operating, for example, on someone with albumin levels of 1.5 g%, you know that you have to do the minimum and to expect troubles after the operation.
Whichever tests are ordered, either by you or by someone else on your behalf (usually the ER doctor), be aware that the significance of the results should never be judged in isolation but considered as part of the whole clinical picture.
Unnecessary Tests
Unnecessary testing is plaguing modern medical practice. Look around you and notice that the majority of investigations being ordered do not add much to the quality of care. Unnecessary tests, on the other hand, are expensive and potentially harmful. In addition to the therapeutic delay they may cause, be familiar with the following paradigm:the more non-indicated tests you order, the more false posi- tive results are obtained, which in turn compel you to order more tests and lead
to additional, potentially harmful, diagnostic and therapeutic interventions.Even- tually, you lose control…
What are the reasons for unnecessary tests?The etiology is a combination of ignorance, lack of confidence, and laziness. When abdominal emergencies are initially assessed by non-surgeons who do not “understand” the abdomen, un- necessary imaging is requested to compensate for ignorance. Junior clinicians who lack confidence tend to order tests “just to be sure – not to miss”a rare disorder.
And experienced clinicians occasionally ask for an abdominal CT over the phone in order to procrastinate. Isn’t it easier to ask for a CT rather than to drive to the hospital in the middle of the night and examine the patient? (“Let’s do the CT and decide in the morning…”).
An occasional surgical trainee finds it difficult to understand “what’s wrong with excessive testing?” “Well” we tell him or her, “Why do we need you at all?
Let us all go home instead, and instruct our ER nurses to drive all patients with abdominal pain through a predetermined line of tests and imaging modalities”.
Patients are not cars on a production line in Detroit. They are individuals who need your continuous judgment and selective use of tests.
Be careful before adopting an investigation claimed to be “effective”by others.
You read, for example, that, in a Boston ivory tower, routine CT of the abdomen has been proven cost-effective in the diagnosis of acute appendicitis. Before succumbing to the temptation to order a CT for any suspected acute appendicitis check out whether the methods used in the original study can be duplicated in your own environment. Do you have senior radiologists to read the CT at 3 a.m. – or would the CT be reported only in the morning – after the appendix is, or should be, in the formalin jar?
Perhaps the day is near, when all patients on their way from the ambulance to the ER will be passed through a total body CT scanner – read by a computer. But then luckily we will not be practicing surgery and this book will be out of print.
We do not believe, however, that patients will fare better under such a system.
Diagnostic Laparoscopy
This is an invasive diagnostic tool (some call it “controlled penetrating ab- dominal trauma”) to be used in the operating room, after the decision to intervene has been already taken. It has a selective role as discussed in > Chap. 51.
The more the noise – the less the fact
”God gave you ears, eyes, and hands; use them on the patient in that order.”
(William Kelsey Fry, 1889–1963)
