Clinical policy: Critical issues for the initial evaluation and management of patients presenting with a chief complaint of nontraumatic acute abdominal pain

Abstract

[American College of Emergency Physicians. Clinical policy: critical issues for the initial evaluation and management of patients presenting with a chief complaint of nontraumatic acute abdominal pain. Ann Emerg Med. October 2000;36:406-415.]

Introduction

This clinical policy expands on the previous Clinical Policy for the Initial Approach to Patients Presenting With a Chief Complaint of Nontraumatic Acute Abdominal Pain that was published in 1994.¹ This topic was initially selected because of the high frequency with which such patients present to emergency departments and the potential for serious adverse outcomes. The format of the original abdominal pain clinical policy focused on the evaluation of a patient presenting with a chief complaint of abdominal pain as opposed to specific disease processes. It was a broad-based attempt to focus on key history, physical, and diagnostic findings to drive the diagnosis of potentially serious medical conditions. Because of the all-inclusive nature of the original format, specific emphasis on critical issues in the evaluation of selected subsets of abdominal pain patients was not possible.

The Clinical Policies Committee believes that the format of the previous complaint-based clinical policies has gone as far as possible in directing the appropriate evaluation and treatment of patients presenting with abdominal pain. The committee is satisfied that the previous policy met the original goals of the American College of Emergency Physicians (ACEP). A decision was made to develop a revised policy that focuses on critical issues in the evaluation of patients with abdominal pain. It is hoped that this new format will not only improve patient care but also direct future research.

Unlike the initial policy, the revised policy does not make exhaustive recommendations regarding the evaluation and treatment of the patient with abdominal pain. Instead it presents important research on critical issues regarding this topic. The revised policy makes recommendations, as much as possible, based on scientific research rather than on the consensus of an expert panel. Evidence-based medicine creates few standards in directing patient care in the ED setting. In addition, this revision presents data concerning laboratory and imaging modalities used to determine the etiology of abdominal pain.

Annually, nearly 5 million patients present to EDs in the United States with the complaint of abdominal pain.² This complaint accounts for 5% to 10% of all ED visits in some areas.³ Etiologies of acute abdominal pain range from minor, self-limiting conditions to life-threatening disorders. Although a majority of patients have conditions that are not life-threatening, failure to identify and treat those patients with serious illness may result in devastating health consequences. Elderly patients are at particular risk for critical conditions. It is not always possible to determine the cause of acute abdominal pain. Studies show that specific diagnoses are not made in approximately 30% of these patients.3, 4

There is no single best method for determining the correct diagnosis and treatment derived from the patients’ symptoms and signs during their ED visit, and therefore this cannot be written in a clinical policy. However, a useful policy should assist in the identification of the most serious and life-threatening conditions based on their common signs and symptoms. A review of the medical literature on abdominal pain found many studies on specific disease entities but very few regarding the overall approach to patients with abdominal pain. Published research on abdominal pain is predominantly retrospective and diagnosis specific. There are few data regarding the emergency evaluation of an undifferentiated complaint. It is clear that future studies are required that analyze the relationship among the signs, symptoms, laboratory analyses, and imaging studies in patients with acute abdominal pain.

The usefulness of ancillary testing depends on many factors: pretest probability, the specificity and sensitivity of the test, and disease prevalence. Many commonly used laboratory analyses and imaging studies are neither sensitive nor specific for a particular diagnosis. The emergency physician should understand the limits of these ancillary studies and should order only those tests likely to affect diagnosis or management. These tests are listed in the Appendix.

This clinical policy is intended for patients with a chief complaint of acute abdominal pain who present to a hospital ED.

Excluded from this policy are:

• Children

• Patients with known antecedent trauma

• Patients in the last trimester of pregnancy or the first month post partum

A MEDLINE search for articles published between January 1990 and January 1999 was performed for abdominal pain management in the ED. Key words consisted of physical examination techniques (eg, auscultation) and specific abdominal conditions (eg, pancreatitis). Radiology and laboratory qualifiers were then applied to each of the abdominal diagnoses. The bibliographies of the individual articles were also searched for additional references, some of which were published before 1990. The subcommittee reviewed these articles to determine those that applied to the selected topics in this revision. These were analyzed by at least 2 subcommittee members and scored for strength of evidence according to the following criteria:

Interventional studies including clinical trials, observational studies including prospective cohort studies, aggregate studies including meta-analyses of randomized clinical trials only.

Observational studies including retrospective cohort studies, case-controlled studies, aggregate studies including other meta-analyses.

Descriptive cross-sectional studies, observational reports including case series, case reports; consensual studies including published panel consensus by acknowledged groups of experts.

Articles with significant flaws or design bias were downgraded in their strength of evidence.

Strength of recommendations were then made according to the following criteria:

Generally accepted principles for patient management that reflect a high degree of clinical certainty (ie, based on “strength of evidence A” or overwhelming evidence from “strength of evidence B” studies that directly address all the issues).

Recommendations for patient management that may identify a particular strategy or range of management strategies that reflect moderate clinical certainty (ie, based on “strength of evidence B” that directly addresses the issue, decision analysis that directly addresses the issue, or strong consensus of “strength of evidence C”).

Other strategies for patient management based on preliminary, inconclusive, or conflicting evidence, or, in the absence of any published literature, based on panel consensus.

The reasons for developing clinical policies in emergency medicine and the approaches used in their development have been enumerated.⁵ This policy is a product of the ACEP clinical policy development process, including expert review, and is based on the existing literature; where literature was not available, consensus of emergency physicians was used. Expert review comments were received from emergency physicians, physicians from other specialties, such as surgeons, and specialty societies including members of the American Academy of Family Physicians, American College of Obstetricians and Gynecologists, and Emergency Nurses Association. Their responses were used to further refine and enhance this policy. Clinical policies are scheduled for revision every 3 years; however, interim reviews are conducted when technology or the practice environment changes significantly.

This guideline is intended for physicians working in hospital-based EDs.