Abdominal Pain

By Dr.Chandima Halahakoon

 

Introduction    

     This chapter illustrates the importance of identifying abdominal pain as a common and significant surgical presentation in emergency and elective settings. It also gives details of basic principles that we need to understand when dealing with abdominal pain.

     Most surgical conditions are painful. One must keep in mind that pain may sometimes be the main worry of the patient. It guides you to the diagnosis. How you manage pain will certainly affect the relationship that you build up with your patient and hence the overall effectiveness of your management. Outward expression regarding painful stimuli may not be proportional to the severity of the pain perceived, and severity of the condition that the patient suffers. A person’s endurance developed over time, the pain sensitivity level, the culture in which the person was brought up, the educational level and many other factors play a part in determining these subjective outward expressions. Remember your attitudes towards pain will be remembered by the patient!

     Abdominal pain is a common surgical presentation. More than 2/3rd^d of presentations to surgical clinics and surgical presentations to emergency departments are due to some kind of abdominal pain. These can be of different severities. In fact, the bulk of the work of a general surgeon would rotate around dealing with abdominal pain. Hence, it is important that every member of the multidisciplinary team of healthcare workers who deals with patients with abdominal pain has a broad knowledge of the basics of abdominal pain and different concepts involved in it.

 

Evaluation and management

     If we are to treat pain effectively, it is imperative that we come to a reasonably accurate complete diagnosis. For this, locating the site of origin of pain, determining the possible pathology and etiology is of utmost importance.

     In the evaluation and management of abdominal pain, there are few basic concepts that one need to understand. They are:

The urgency of the situation.

The importance of an accurate, complete diagnosis.

Different parts of the abdomen, from which pain can arise.

Basic differences in aetio-pathogenesis of abdominal pain.

Different management options for different types of abdominal pain.

Pitfalls – the possibility of medical conditions as the cause of pain.

 

The urgency of the situation

     Frequently abdominal pain presents as a surgical emergency. The first important aspect of managing pain is to identify the urgency. The speed at which we deal with that patient, priority that we offer that patient, choice of investigation and urgency of attention would all depend upon the urgency of the presentation. On the other hand failure to identify the urgency commonly leads to complications and litigation.

     Generally the two factors to consider are the presence of peritonism and haemodynamic instability. Presence of any or both warrants urgent attention. In the absence of either of the two, we can safely (but not conclusively) rule out urgency at that moment of evaluation. But an important factor to remember is that our evaluation is a point evaluation of the patient’s condition and that it can always change, hence repeated evaluations to look for any deterioration are very important, in order to avoid missing any developing urgency.

     Blood, pus, bile, and bowel contents are all irritants to the peritoneum. Presence of these in touch with the peritoneum would irritate it: thus producing peritonism. We call such an abdomen an “acute abdomen”. Peritonism will be either localized or generalized, depending on whether the irritant is localized to a specific part of the peritoneum or diffusely present. Obviously a diffusely present irritant poses a higher grade of urgency than a localized one.

     We may find tell-tale signs and symptoms of peritonism as we do a systematic evaluation of patient’s clinical situation. A thorough general examination is often rewarding. A patient with peritonism will look ill, will be in pain, will be dehydrated and pale. He/she may not want to move the abdomen and will have very shallow abdominal breathing to minimize movements of the peritoneum. On inspection of the abdomen proper, we may find the affected part of the abdomen showing minimal respiratory movements compared to other parts. When asked to cough, the patient may be hesitant as it aggravates the pain. The area will be tender. Tenderness and rebound tenderness are signs of significant irritation. Guarding and rigidity are voluntary efforts to keep the peritoneum still in an effort to prevent it moving about; thus they denote higher grades of irritation.

     A rapid thready pulse, cold clammy extremities and low blood pressure indicates bleeding as the cause. Low volume rapid pulse with low blood pressure may indicate sepsis as the cause.

 

The importance of an accurate, complete diagnosis

     An accurate complete diagnosis is imperative for the successful management of abdominal pain. Anatomy, pathology, etiology, complications and disability domains of a disease entity should be described in a complete diagnosis.

     A thorough knowledge of the anatomy of the abdominal cavity with its different regions and the structures contained within those is the first important step in accurate diagnosis. A knowledge in aetio-pathogenesis of different conditions that can give rise to abdominal pain, the differing clinical features of these and how these clinical symptoms and signs are brought about is the next most important factor. A sound knowledge of possible complications of different aetio-pathologies is important as they would pose a higher degree of urgency, and on the other hand, they themselves may present on their own as complicated abdominal pain. Apart from the urgency, the disability level of the patient (due to the current painful abdominal condition in consideration) may also influence the clinician’s approach.

 

Different parts of the abdomen, from which pain can arise

     Traditionally the abdomen is divided into nine quadrants (right and left hypochondria, epigastrium, umbilical area, right and left lateral quadrants, right and left ileac fossae and the supra-pubic region) by two imaginary horizontal lines (lower border of L1 and ileac crest level) and two vertical lines (mid-clavicular lines on both sides). Pains localized to these different regions of the abdomen may indicate pain arising from particular organs located in that region. For example, pain arising from the gall bladder is in the right upper quadrant and pain arising from the small intestine is in the umbilical area.

     One must not forget that parts of the abdomen may be hidden in other parts of the body. Examples are the upper parts of hypochondria and epigastrium hiding under the lower rib cage, lower parts of ileac fossae and the supra-pubic region hiding in the pelvis. Hence the origin of a lower thoracic or a pelvic pain may in fact be really the abdomen. On the other hand vice versa is also true, i.e., a pain in the upper abdomen or lower abdomen may in fact be of lower thoracic of pelvic in origin.

     One other factor needing consideration is that the origin of the pain may really be from the two walls of the abdomen i.e. anterior and posterior abdominal walls. Some of the anterior abdominal wall pathologies can also present as abdominal pain; examples are rectus sheath hematoma, musculo-skeletal pain, Herpes Zoster, spinal nerve impingement and psoas abscess. Many of the important organs in the region of abdomen are within these walls (kidneys in the posterior abdominal wall).

     It is important to appreciate that pain from a particular organ will be always localized to the specific quadrant in which it is located. But if the causative factor is migrating from one site to another, then the site of pain may move as well (e.g., a ureteric colic); this is called radiation of pain. Sometimes as the inflammation proceeds to involve different dermatomes, the pain may then be referred to other dermatomes (e.g., appendicitis).

 

Basic differences in aetio-pathogenesis of abdominal pain

     A basic analysis of the different characteristics of pain always gives an insight into the aetio-pathogenesis of the disease entity.

     The most important aspect in this regard is the site of pain (discussed earlier).

     The next most important aspect is the analysis of the character of pain. Pain can arise from solid viscera when they are over distended, stretched or inflamed. Such pain is normally continuous (e.g., pancreatitis, hepatitis). Whereas pain from hollow-viscera can arise when they are inflamed or when they are obstructed. When a hollow-viscus is inflamed (e.g., gastritis) it produces a similar pain as that of solid viscera but when they are obstructed the pain is colicky in nature (e.g., ureteric colic, biliary colic).

     Next in line of importance is the quality of the pain. A burning pain in the epigastrium is suggestive of gastritis. Sharp pain in the epigastrium going to back may suggest a leaking abdominal aortic aneurysm.

     Aggravating and relieving factors also help in coming to a diagnosis. Examples are a fatty meal may precede biliary colic, food might relieve pain of gastritis or food might aggravate pain of duodenitis.

     There are many other features that could help you to come to a judgment regarding the diagnosis. Age may give a clue: for example intususception in a six months old child, or diverticular disease in the elderly. Acuteness/chronicity may also put some light on the diagnosis: for instance a long standing epigastric pain radiating to back may suggest chronic pancreatitis as opposed to a shorter duration epigastric pain suggesting acute gastritis.

     Clinicians should also look for the other associated tell-tale symptoms and signs of the etiology. Obstruction of the bowel may produce vomiting at an earlier phase of the disease activity if the obstruction is high up. Vomiting may be a later feature in distal bowel obstruction. Vomitus will be bilious if the obstruction is close to and distal to second part of duodenum. Other features to look for would be the nature of bowel motions, appetite, presence of fever, any upper/lower gastrointestinal symptoms, nature of bowel sounds, presence of hernia, etc.

 

Different management options for different types of abdominal pain

     Specific management options for a given condition would depend on the exact diagnosis and the urgency. We must look for and recognize any clinical urgency of the situation and attend to it appropriately. This may mean urgent surgery or stabilization of the patient and transfer, depending on your local resources.

     In the absence of any urgency, the most suitable analgesic should be selected, depending on the type, severity and diagnosis; for example NSAIDs in ureteric colic and opioids in visceral pain. Combinations are preferred, but avoid poly-pharmacy as it can lead to unnecessary side effects, drug interactions and a heavy cost to the patient without any added benefit. Pain killers should be used according to the WHO ladder at regular intervals, with allowance for break through pain. Pain management protocols should cater to the individual needs of our patients, considering the factors affecting the response to painful stimuli. The clinicians should recognize that the management of pain is a dynamic (not static) process. Hence the protocols should be reviewed regularly to address newer needs.

     It is imperative that we treat the cause of pain effectively; else the efforts to combat pain symptomatically will be a fruitless exercise. This may mean a surgery for instance in acute appendicitis or antibiotics as in acute cholecystitis.

     Adjuvant therapeutic measures may also help in combating pain (e.g., NG tube in acute pancreatitis to empty the duodenum, propantheline in bowel colic).

     It is important to assess the response to the executed pain management protocol objectively, for example, by using a visual analogue scale, to see any improvement. Subjective pain assessment, such as direct questioning or mere observations are discouraged as outward expressions of pain can vary considerably. When there is no or minimal response, apart from changing the protocol of pain management, it is prudent to reconsider the diagnosis, which may be the reason for the lack of response.

 

Pitfalls – the possibility of medical conditions as the cause of pain

     There are many medical conditions that may present themselves as abdominal pain. Diabetic ketoacidosis, inferior myocardial infarction, lower lobe pneumonia, pericarditis and pleurisy are a few of them.

     Therefore in suspicious cases it is always prudent to be alert for such rare and infrequent presentations. But one should be extremely vigilant to rule out possible surgical causes before considering these medical entities as the causation of abdominal pain; else the consequences to the patient can sometimes be fatal; for example, a missed leaking abdominal aortic aneurysm.

 

Summary

     We have discussed the importance of proper evaluation of abdominal pain in detail in order to come to a reasonable diagnosis, so that we can optimally manage the condition. We have also explored the broad options available to the clinicians in dealing with abdominal pain, together with pit falls that we would like to avoid.

     Details of pharmacological and non-pharmacological options in managing abdominal pain will be found in the other relevant chapters. As this is neither an exhaustive account of a comprehensive differential diagnosis of abdominal pain nor a detailed account of aetio-pathogenesis of all painful abdominal conditions, readers are invited to read the suggested reading material for further information.

 

References

Murtagh J.  Murtagh’s General Practice (4th edition). Melbourne: Mc Graw Hill; 2007; 34.

Russell RCG, Williams NS, Bulstrode CJK. (Eds) Bailey & Love’s Short Practice of Surgery (23^rd edition). London: Arnold; 2000; 51 – 65.

Townsend CM, Beauchamp RD, Evers BM, Mattox KL (Eds). Sabiston Text Book of Surgery (18th edition). Philadelphia: Saunders; 2008; 45.