Adam Jones, Kevin Turner, and Ashok Handa guide you through the early management of abdominal pain

Abdominal pain is common, accounting for around 1% of all admissions to hospital.¹ The trouble with surgical textbooks is that abdominal pain is classified by system, which is fine for written exam answers but does not help much when you're faced with a patient, except to remind you of the many possible diagnoses in front of you. Many of these are not life threatening. In some, however, rapid diagnosis and treatment can save lives. In theory you will never have to face these serious cases alone as a house officer, but in practice you may have to. Do not panic - it is not as daunting as you may think if you follow a few basic principles.

This article will tell you these basic principles that will get you through the initial presentation." It is not textbook stuff for written exams, as you can easily learn lists of symptoms and signs, but it is sound practical advice that is good for vivas and ward rounds, and may save your skin (and your patients).

On your way to accident and emergency

There are two things to remember as you make your way quickly to your patient. Firstly, remember the conditions that are less common but life threatening. Against this, do not forget that common things are common.

The first 20 seconds

When you first see the patient there are only three diagnoses:

Very ill; ill; and reasonable/well.

So ask yourself three questions.

(a) Is this patient seriously ill and maybe going to die imminently? If you think this is a possibility, call a senior member of your team immediately for help. If your team is unavailable ask one of the ward's senior house officers or specialist registrars for help. It is to your credit to realise when you are out of your depth; everyone has been there. Anyway, real emergencies need more than one pair of hands.

(b) Is the patient ill but probably stable for the next couple of hours? In this case you have time to get urgent investigations done, formulate your diagnosis, and start initial management. Your treatment may help the patient, by making a decision you will learn, and your investigations will certainly help your registrar.

(c) Is the patient actually quite well? Investigate as appropriate and try to commit yourself to a diagnosis before calling your registrar.

Of course, categorising patients like this is not always easy - for example, a patient with a ruptured abdominal aortic aneurysm that has tamponaded may not look too bad, only to crash precipitously a few minutes later as his/her blood pressure rises. But generally speaking, a patient who is pale, clammy, and looks close to death probably is close to death. A patient sitting up, joking with his family, and looking well probably is well. Remember, no one minds being called early for advice but everyone hates being called late.

The patient's age is important for two reasons. The likelihood of different conditions is different within different age groups. Up to 10% of severe abdominal pain in the elderly will have a vascular cause (ruptured abdominal aortic aneurysm (AAA), mesenteric ischaemia or thrombosis). Perforated large bowel (diverticular disease or carcinoma) is more common than appendicitis in elderly people, and faecal peritonitis in this age group is associated with a high mortality. In children appendicitis is common, but remember intussusception ("redcurrant jelly" rectal bleeding) in younger children. Pancreatitis is serious and can occur at any age, but especially in the medium age group (possibly of gallstone origin in women or alcohol in high risk groups - for example, publicans). In younger women, always consider gynaecological causes, especially ectopic pregnancy.

A patient's age may thus help to narrow down the possible diagnoses but is also important for another reason. Elderly patients have fewer reserves than younger patients and therefore tolerate the physiological insults of serious abdominal pathology poorly. This means that morbidity and mortality are higher than in a younger population.

Very young patients suffer from the same problems. If you see any child that looks unwell rather than just grizzly, get help sooner rather than later as these patients can deteriorate rapidly.

 

When young women present with abdominal pain, gynaecological causes must always be considered (BSIP V AND L/SCIENCE PHOTO LIBRARY)

If the patient is obviously very ill you will have to treat and diagnose at the same time. The fact that s/he is so ill may, however, narrow the diagnosis (depending on the duration of symptoms) so concentrate on these diagnoses first: ruptured abdominal aortic aneurysm; perforation; pancreatitis; or myocardial infarction. Here are a few tips to help you make the diagnosis.

The pain

The site of the pain will help diagnosis. Pain going through to the back suggests ruptured abdominal aortic aneurysm or pancreatitis. Ask the patient if s/he has any swelling of the main artery (many patients will have had an abdominal aortic aneurysm diagnosed and are on surveillance or have been refused elective operation for medical reasons). If a patient puts his/her hand behind his/her back, with their fingers in the loin and their thumb pointing towards their umbilicus, this strongly suggests renal colic. But beware diagnosing left sided renal colic in an elderly patient whose history is not typical. It is not unusual for the only calcium to show up on their emergency intravenous urogram to be in the wall of their abdominal aortic aneurysm.

Is the patient lying perfectly still? This suggests peritonitis. Writhing around in agony suggests biliary or renal colic.

The onset and duration of the pain will also help. Perforation and rupture usually have a dramatic onset. It may also indicate how unwell the patient is. It is not uncommon for stoics to present many hours after the onset of their pancreatitis or perforation, because they did not want to trouble their doctor. These patients will be more severely dehydrated and require more vigorous resuscitation.

Previous history

Any previous abdominal surgery means that adhesions leading to obstruction or strangulation is a possibility. Ask about this and look for scars.

If you suspect pancreatitis, ask about previous gallstones and alcohol intake, but do not expect an honest answer. Measuring serum concentrations of amylase is therefore essential in all patients with abdominal pain.

Because ruptured ectopic pregnancy can kill always ask about recent menstrual and sexual history. But again, remember that it is not uncommon for patients to deny sexual intercourse and subsequently be found to be pregnant. Since there is also one very well reported case of this in the world literature, always do a urine pregnancy test, regardless of the sexual and menstrual history.

Two things not to forget

Always examine hernial orifices. A small strangulated femoral hernia in the groin crease of an overweight elderly woman is easily missed unless you look for it.

Do not forget non-surgical causes. The xiphisternum is jokingly called the orthopaedic auscultation point, because you can check heart, breath, and abdominal sounds all in one without moving your stethoscope. Remember this joke, however, and you will remember to consider that the epigastric pain that you think is gastritis, or the right hypochondrial pain that you think is acute cholecystitis, may in fact be a myocardial infarction and right basal pneumonia.

Immediate management

If the patient is seriously ill call for immediate senior help. Even if your diagnosis and management are spot on, two sets of hands will greatly speed things.

Although the problem is in the abdomen, remembering to go through the Airway, Breathing, Circulation (ABC) of emergency care will remind you to give 100% oxygen. These patients are ill and require all the support you can give them. Get venous access. Use the largest cannulae you can (preferably grey or brown). Insert two and withdraw blood for investigations (essential are full blood count, measurement of urea and electrolytes, amylase, clotting, group and save (minimum, if not crossmatch)).

Start intravenous fluids. What and how much depends on what the diagnosis is and how dehydrated the patient is. If you have no immediate clue about either, 1 litre normal saline over four hours will do no harm, may do some good, and you can adjust this as soon as the picture becomes clearer. Put the patient "nil by mouth."

Get an electrocardiogram.

Catheterise, measure urine output hourly and send urine for urgent human chorionic gonadotrophin in women of childbearing age.

Frequently monitor temperature, pulse, respiration rate and blood pressure. Remember the absolute values provided at baseline are important, but the temporal progression is even more critical, acting as a guide to indicate how well your management is doing.

Get erect chest and abdominal x ray films. If the patient's condition is unstable, this should be done with a portable x ray machine, rather than the patient going to the radiology department.

Subsequent management

If the patient is elderly and at greater risk of cardiac failure, preoperative resuscitation and postoperative fluid balance are harder to assess. Some of these patients should have a central line to monitor central venous pressure. Remember, however, that insertion of a central line is associated with complications (pneumothorax, haemorrhage). In the emergency situation central lines look dramatic but are not as good as shorter peripheral cannulae for rapid infusion of fluid. In all patients, continue to monitor fluid balance using clinical signs and basic observations.

Remember, analgesia is essential.

Conclusions

To pass finals your examiners are not just testing your factual knowledge, what they are actually asking is: "If this person was my house officer would my patients be safe with them?" Thinking about abdominal pain in the way we have described here will help you to be safe; becoming an expert will come with time.

Top tips

Common things are common, but consider less common but life threatening diagnoses.

• All patients with abdominal pain should have serum concentrations of amylase measured.
• Abdominal pain in women of child-bearing age necessitates performing a pregnancy test.
• The trend in vital functions is as, if not more, important than their absolute values.
• Patients at age extremes often have non-specific symptoms and can deteriorate rapidly.