Management of abdominal pain in children

Introduction

Abdominal pain, or “tummy ache”, is one of the most common reasons for a parent to bring the child to medical attention.¹Available at: http://www.emedicinehealth.com/abdominal_pain_in_children/article_em.htm. Accessed on 25.01.2012.   In fact, it is the most common type of pain in younger children and the second most common type, after headache, in older children and adolescents.²Bufler P, Gross M, Uhlig HH. Recurrent Abdominal Pain in Childhood. Dtsch Arztebl Int 2011; 108(17): 295-304.  Besides directly affecting the child, abdominal pain in children is often frightening and frustrating for parents. Issues related to evaluating and managing a child with abdominal pain further complicate the situation since many times it is hard to find the exact cause of a child’s abdominal pain.³Available at: http://children.webmd.com/tc/abdominal-pain-age-11-and-younger-topic-overview. Accessed on 25.01.2012. Nevertheless, each case should be managed promptly to avoid prolonging the child’s discomfort; also, abdominal pain is sometimes a sign of life-threatening disease.

Causes of abdominal pain in children

The origin of abdominal pain is complex and does not lend itself to a single model of causation.⁴Devanarayana NM, Rajindrajith S, de silva HJ. Recurrent Abdominal Pain in Children. Indian pediatrics 2009;46:389-99.  ^,5Shashidhar H, Omar HA. Recurrent Lower Abdominal Pain in Older Children and Adolescents: Revised Clinical Approach. The Scientific World journal 2005;5:64-70.   Considering clinical pathogenesis, abdominal pain falls into three categories: visceral (splanchnic) pain, parietal (somatic) pain, and referred pain (Table 1).⁶Leung AKC. Acute abdominal pain in children. Am Fam Physician 2003;67:2321-6.   Possible causes for a child’s abdominal pain range from trivial to life-threatening etiologies, with little difference in the child’s complaints.1 Figure¹Available at: http://www.emedicinehealth.com/abdominal_pain_in_children/article_em.htm. Accessed on 25.01.2012.   depicts some common causes of acute abdominal pain in children.

Clinical evaluation

Evaluating any child with abdominal pain is particularly meticulous for the physician. A thorough history is essential to identify the most likely cause, followed by a physical examination and a reassessment of certain points of the history (Figure 1, 2)⁶Leung AKC. Acute abdominal pain in children. Am Fam Physician 2003;67:2321-6.; essentially it should be performed in a stepwise manner.

History

History taking focuses on description of symptoms that permit presumptive etiopathological diagnosis.⁵Shashidhar H, Omar HA. Recurrent Lower Abdominal Pain in Older Children and Adolescents: Revised Clinical Approach. The Scientific World journal 2005;5:64-70. Age is an important factor while evaluating abdominal pain in relation to differential diagnosis (Figure 3)⁶Leung AKC. Acute abdominal pain in children. Am Fam Physician 2003;67:2321-6., and this may also affect the pain history; while non-verbalizing children typically present with late symptoms of disease (the initial 24-h history of vague nausea or periumbilical pain may be unreported or go unnoticed), children up to the teenage years usually have a poor sense of onset or location of pain. Therefore, it is important that the inquiry into important points such as location, onset, character, severity, duration, and radiation of pain must be viewed in the context of the child’s age.

The cause of pain may be more evident if there is history of recent trauma. The progress of pain and its modulation may also point toward the possible origin. While pain aggravated by movement points a parietal origin, relief in pain following a bowel movement suggests a colonic source, and relief following a vomiting episode suggests a source in the more proximal bowel.

Diarrhea though often associated with food poisoning or gastroenteritis can occur with other conditions. In particular, bloody diarrhea is much more suggestive of inflammatory bowel disease (IBD) or infectious enterocolitis. Failure to pass feces or flatus is suggestive of intestinal obstruction. Cough, shortness of breath, and chest pain point to a thoracic source, and urinary frequency, urgency, dysuria, and malodorous urine suggest urinary tract infection (UTI). A thorough gynecologic history, including a menstrual and sexual history, is important in girls.

Also, it is important to have a detailed past medical, surgical and drug history before establishing any association. A history of similar pain in the past may suggest a recurrent problem. Family history is also important to rule out any genetic predisposition.

Examination

A thorough physical examination is important before proceeding to any specific investigation that is often backed by a positive finding on initial examination. The hydration status of the child should be assessed. Fever indicates an underlying infection or inflammation, and tachycardia and hypotension suggest hypovolemia. Associated signs such as jaundice may also help in establishing the possible etiology.

Generally, children with visceral pain tend to writhe during peristaltic waves; however, children with peritonitis usually remain quite still and resist movement. The breathing pattern should be observed while performing abdominal examination. Also, the child should be asked to indicate, with one finger, the area of maximal tenderness in the abdomen. While gentle percussion best elicits rebound tenderness, assessment of organomegaly requires deeper palpation.

Rectal and pelvic examination should be performed only when necessary and when significant information is sought or expected. A rectal examination may help to elicit tenderness, sphincter tone, and presence of masses, stool, and melena. Furthermore, pelvic examination may reveal characteristic findings based on gender.

Investigations

Laboratory studies should be customized to the patient’s signs and symptoms and findings elicited on clinical examination. While specific investigations are required in only certain cases, initial investigations may include a complete blood cell count and urinalysis.

Radiography may also assist in diagnosis. Plain-film abdominal radiographs are useful in cases of suspected intestinal obstruction or when perforation of a viscus in the abdomen is a concern. Similarly, chest radiographs may help to rule out pneumonia.

The choice of imaging study or an endoscopy as an initial test depends on clinical presentation (Figure 4).⁵Shashidhar H, Omar HA. Recurrent Lower Abdominal Pain in Older Children and Adolescents: Revised Clinical Approach. The Scientific World journal 2005;5:64-70.   Whether to use ultrasonography and/or computed tomography (CT) in patients with abdominal pain is a contentious issue in emergency medicine; both modalities have their intrinsic utilities in diverse situations. Both clinical patterns of presentation and disease process and operational issues in emergency should govern the decision to use any particular investigation.

Management

The diluted presentation with indistinct symptoms often makes it difficult for the parent and/or caregiver to decide whether a complaint needs emergency care or not.¹Available at: http://www.emedicinehealth.com/abdominal_pain_in_children/article_em.htm. Accessed on 25.01.2012.   In general, treatment should be directed at the underlying cause. In many patients, the key to diagnosis is repeated physical examination by the same physician over an extended time.

Traditionally, the use of analgesics (anti-cholinergic anti-spasmodic) are discouraged in patients with abdominal pain for fear of interfering with accurate evaluation and diagnosis.⁶Leung AKC. Acute abdominal pain in children. Am Fam Physician 2003;67:2321-6.   They often mask the physical “acute abdomen” making it difficult to achieve a rapid diagnosis on reaching the hospital. Also, sedation caused by analgesics (anti-cholinergic anti-spasmodic) may interfere with diagnostic evaluation related to

central nervous system (CNS) function.⁷Jones JD, Ramakrishnan K. Analgesics In The Initial Management Of Acute Abdominal Pain. The Internet Journal of Emergency Medicine 2005;2(2).  Box 1 shows some of the side-effects that may be encountered with use of anti-cholinergic anti-spasmodics.⁸http://www.drugs.com/mtm/antispasmodic.html. Accessed on 15.02.12.

Nevertheless, this is an important real-life scenario that requires judicious use of drugs since the patient would cooperate for physical checkups only once pain has subsided. Accordingly, there exists the need of an agent that provide prompt relief without masking the underlying etiology of the acute abdominal pain. Anti-spasmodics can be used in emergency situations related with smooth muscle spasm, and thereafter prompt diagnostic evaluation may help in deciding the optimal treatment regimen/modality based on underlying etiology.

Drotaverine: A convenient anti-spasmodic in managing abdominal pain

Members of the synthetic isoquinolines possess a powerful spasmolytic action on smooth muscle cells, and drotaverine is an isoquinoline derivative. It is a selective inhibitor of phosphodiesterase isoenzyme IV, and has been found useful is spastic and motility disorders of the smooth muscle.⁹Misra SC, Pandey RM. Efficacy of drotaverine in irritable bowel syndrome: a double blind, randomized, placebo-controlled clinical trial. The American Journal of Gastroenterology 2000;95:2544.  Characteristically, while spasmolytics are known for their ability to inhibit intestinal passage, preclinical studies showed that at therapeutic concentrations drotaverine does not have inhibitory effect on gastrointestinal motility.

Also, drotaverine does not have any morphine or dextropropoxyphene like effect, and, thus, do not result in addiction. The preclinical pharmacokinetic and metabolism data showed an excellent absorption of drotaverine from the small intestine. Likewise, in humans the half-life of absorption was 12 min after oral dosing; the drug was quickly absorbed, with maximum plasma concentration appearing within 45 min. About 65% of the dose reaches unchanged in the systemic circulation.¹⁰Blasko G. Pharmacology, mechanism of action and clinical significance of a convenient antispasmodic agent. JAMA India;4(12).

The beneficial effect of oral drotaverine is emphasized in therapy of spastic pain; in fact, oral administration of drotaverine would help in prolonging the pain-relief, and is efficacious for the maintenance of spasmolysis. The disappearance of pain was found to begin 5-6 minutes in cases of spastic pain due to gastrointestinal ulcer; the effect was completed within 12 minutes, and patients did not report abdominal pain. Studies evaluating the prescription profile of the usage of drotaverine and its efficacy in different gastrointestinal indications found pain-relief in 72% – 86% of patients.

Accordingly, it shows that drotaverine is a highly potent and safe spasmolytic agent, suited for oral administration, and capable of relieving or preventing smooth muscle spasm of various organs. In fact, it contributes very effectively in relieving painful spasms in a large variety of diseases, including those of gastroenterological origin. Essentially, the anti-spasmodic and pain-killing effect of drotaverine does not mask the symptoms of “acute abdomen”; a feature making it unique in the group, and may have relevant application in practice to achieve a rapid diagnosis.10 The drug is free of the side-effects associated with anticholinergic anti-spasmodics such as dicyclomine etc. Box 2 shows some of the benefits of using drotaverine suspension for acute abdomen.

The rapid absorption and onset of efficacy, the wide therapeutic window, repetitiveness, possible coadministration with analgesics possibly made it a favorite drug in emergency medicine. Drotaverine could be given in cases without finalized diagnosis; pre-treatment in the emergency situation resulted in decrease of pain and spasm, without interfering the association of correct diagnosis.

Dosage of oral drotaverine in children:

• Children of 1-6 years age: Per kg body weight dose = 2 mg or 1 ml TID not to exceed 120 mg per day
• Children of 6-12 years age: 40-60 mg or 20-30 ml TID or as required up to 200 mg

Interestingly, the recent European report on the survey of all pediatric uses of medicinal products in Europe showed that drotaverine is used commonly in preschool and school children.¹²Data on File. Walter-Bushnell.

Conclusion

Acute abdominal pain is common in the pediatric population and is particularly challenging in its management. In general, the care providers need to optimize the measurement, documentation, and treatment of pain in children.¹³ S, Ali H. Treating Abdominal Pain in Children: What Do We Know? Clinical Pediatric Emergency Medicine. 2010;11(3):171-81.   However, there remains a gap between what we know to be effective, easily implemented pain management strategies, and what is actually practiced.¹⁴MacLean S, Obispo J, Young KD. The gap between pediatric emergency department procedural pain management treatments available and actual practice. Pediatr Emerg Care. 2007;23(2):87-93.

It is important that the analgesic used does not mask the underlying pathology, to have prompt diagnosis. Drotaverine, an anti-spasmodic, serves this purpose quite well as it does not mask the symptoms of “acute abdomen”, and, thus, may be valuable both as initial drug used for pain-killing effect in a child presenting with abdominal pain, and for maintenance of spasmolysis. The drug exhibits rapid absorption and onset of efficacy, and a wide therapeutic window, and can be given effectively in cases without a final diagnosis to decrease pain and spasm, without interfering the association of correct diagnosis. Moreover, it is free of the side-effects associated with anti-cholinergic anti-spasmodics.

References

1. Available at: http://www.emedicinehealth.com/abdominal_pain_in_children/article_em.htm. Accessed on 25.01.2012.
2. Bufler P, Gross M, Uhlig HH. Recurrent Abdominal Pain in Childhood. Dtsch Arztebl Int 2011; 108(17): 295-304.
3. Available at: http://children.webmd.com/tc/abdominal-pain-age-11-and-younger-topic-overview. Accessed on 25.01.2012.
4. Devanarayana NM, Rajindrajith S, de silva HJ. Recurrent Abdominal Pain in Children. Indian pediatrics 2009;46:389-99.
5. Shashidhar H, Omar HA. Recurrent Lower Abdominal Pain in Older Children and Adolescents: Revised Clinical Approach. The Scientific World journal 2005;5:64-70.
6. Leung AKC. Acute abdominal pain in children. Am Fam Physician 2003;67:2321-6.
7. Jones JD, Ramakrishnan K. Analgesics In The Initial Management Of Acute Abdominal Pain. The Internet Journal of Emergency Medicine 2005;2(2).
8. http://www.drugs.com/mtm/antispasmodic.html. Accessed on 15.02.12.
9. Misra SC, Pandey RM. Efficacy of drotaverine in irritable bowel syndrome: a double blind, randomized, placebo-controlled clinical trial. The American Journal of Gastroenterology 2000;95:2544.
10. Blasko G. Pharmacology, mechanism of action and clinical significance of a convenient antispasmodic agent. JAMA India;4(12).
11. Available at:Report on the survey of all paediatric uses of medicinal products in Europe. Available at: http://www.ema.europa.eu/docs/en_GB/document_library/Report/2011/01/WC500101006.pdf. Accessed on 27.01.2012.
12. Data on File. Walter-Bushnell.
13. Ali S, Ali H. Treating Abdominal Pain in Children: What Do We Know? Clinical Pediatric Emergency Medicine. 2010;11(3):171-81.
14. MacLean S, Obispo J, Young KD. The gap between pediatric emergency department procedural pain management treatments available and actual practice. Pediatr Emerg Care. 2007;23(2):87-93.