Key points

Introduction

Gastrointestinal (GI) emergencies accounted for nearly 15 million of the 122 million emergency department (ED) visits in the United States in 2007 at a cost of $27.9 billion. Traditionally, the care of a patient with abdominal pain was to perform a rapid diagnostic workup with efforts aimed at relief of symptoms. After the initial ED workup, patients would be either discharged home or admitted to a surgical or medical inpatient service. The ED provider, under pressure to rapidly and accurately diagnose and treat patients, has increasingly relied on early radiographic testing. The difference in imaging utilization for abdominal complaints rose from 19.9% in 1999 to 44.3% in 2008. Some patients may benefit from a period of time during which they may undergo further diagnostic workup, risk stratification, and treatment before a final disposition. ED Observation Units (EDOUs) have the potential to improve diagnostic accuracy with more judicious use of imaging modalities, lower morbidity and mortality, improve the patient experience, and reduce health care expenditures.

The potential for EDOUs to reduce patient exposure to ionizing radiation deserves special emphasis. Recent studies in the trends of computed tomography (CT) use in the ED have revealed a tradeoff between the ability to diagnose high-risk conditions more rapidly at the expense of increased cost and increased exposure to radiation and iodinated contrast agents. This is further compounded by the discovery of incidental findings that necessitate potentially needless additional diagnostic testing. The incidence of adrenal “incidentalomas,” a term coined to denote the presence of an adrenal mass in an otherwise asymptomatic patient, found on CT scans approaches 9%. The risk of ionizing radiation is dependent on the dose, tissue exposed, and age of the patient. A CT scan of the abdomen and pelvis exposes the patient to 10 mSv or 3 times the expected annual natural background radiation dose. This exposure, especially when occurring earlier in life, has been associated with a small increase in interval development of cancer. This risk is small to the individual, but given the magnitude of the population that is exposed, the cumulative impact on increased cancer rates is significant.

EDOUs balance the need to accurately and safely diagnose and treat patients with the pressure to do so rapidly but with judicious use of imaging. This balance is achieved by combining the ED assessment with standardized risk assessment tools and serial examinations, a core principle of observation medicine. For lower-risk cases for which no imaging has been performed as part of the initial ED evaluation, the period of observation provides the opportunity to perform repeat assessments of the patient’s condition and to obtain imaging in the event of clinical worsening or failure to improve.

EDOU protocols pertaining to GI complaints will share many common themes. These include standard inclusion and exclusion criteria that exist to select for the most appropriate patient who would benefit from the time in the unit. These criteria must be individualized to local system needs and updated as systems change or new knowledge in the care of conditions evolves.

Inclusions and exclusions are considered on 3 levels: the health care system level, the general patient level, and within the specific patient protocol. Considerations at the level of the health care system include capacity constraints, availability of required resources, unit factors, and team factors. Risk tolerance is proportional to the ability of a system to provide the resources needed for a change in patient status. An example of a unit factor to consider is the presence of individual rooms versus a communal space that is set apart by curtains. The latter would not be conducive for the care of patients with communicable diseases, diarrhea, or those being prepared for a colonoscopy. The team treating the patients placed in the EDOU should have the required skills and expertise to care for the conditions that are likely to be encountered.

Abdominal pain has an exhaustive differential diagnosis that ranges from very low-risk conditions, such as constipation, to catastrophic conditions, such as a ruptured abdominal aortic aneurysm. General exclusion criteria include patients with unstable vital signs, presence of a surgical abdomen, or severe sepsis, or if the diagnostic workup reveals any emergent surgical condition. Patients who are immunocompromised are often not ideal candidates for placement in the EDOU. The severity of their condition is often not evident on initial evaluation and their care involves utilization of multiple resources. Patients with higher-risk immunosuppressive states, such as those who have received transplantation or those with malignancy undergoing chemotherapy, those with human immunodeficiency virus/AIDS, and those with rheumatologic conditions requiring immunosuppressive agents may have very atypical presentations of GI illnesses, such as peritonitis, opportunistic infections, graft-versus-host-disease, and neutropenic enterocolitis. There are some disease-specific conditions that are not likely appropriate for the EDOU. These include conditions in which it is known that the patient will require a prolonged in-hospital stay, such as severe gastroparesis. High-risk conditions should be thoroughly considered in patients with risk factors before placement in the EDOU. One example is consideration of mesenteric ischemia in patients with a history of atrial fibrillation, cardiomyopathy, and other low-flow states.

The provider should consider that several emergent conditions may initially appear to have a GI etiology. Misleading complaints include epigastric pain of an inferior wall acute myocardial infarction, right upper quadrant pain of hepatic congestion in congestive heart failure, generalized abdominal pain with nausea and vomiting in diabetic ketoacidosis, and back and flank pain in pulmonary embolism.

Abdominal pain is the most common chief complaint among the elderly presenting to the ED. Patients older than 80 have nearly double the mortality of younger patients if the diagnosis is delayed. Due to physiologic changes caused by lax abdominal wall musculature and increased use of medications, elderly individuals often have atypical or muted signs and symptoms, including lack of vital sign alteration, such as fever or tachycardia. Only 17% of elderly individuals with a perforated appendix have classic complaints. Age-related physiologic changes may warrant exclusion of elderly individuals from some EDOU GI protocols.

Behavioral and social factors may preclude a reasonable safe disposition within the usual timeframe for EDOU care. For example, it may be unreasonable to perform an observation protocol for acute pancreatitis on a patient who also has symptoms of alcohol withdrawal due to ongoing behavior conditions that had previously occurred. This may affect the care of the patient, as well as the care of other patients in the EDOU.

Each health care system and ED team must consider a general approach to the patient with GI disorders that reflects the abilities of the system and all of its resources, including consultant availability and provider abilities and resources. General patient considerations of catastrophic conditions, immunosuppression, mimic condition considerations, elderly, and behavioral and social factors must be considered before consideration to place in an observation protocol.

Specific patient protocols use best clinical practices and available evidence to standardize care. EDOUs may be used for the evaluation and possible treatment of appendicitis, GI bleeding, and pancreatitis.