Consensus on the diagnosis and treatment of non-traumatic acute abdomen in elderly patients

Non-traumatic acute abdomen (NTAA) in elderly patients is a clinical syndrome characterized by acute abdominal pain in individuals aged ≥65 years without any trauma. NTAA usually results from acute or subacute pathological processes involving intra-abdominal or abdominal wall structures and often requires prompt diagnosis and treatment.^[1] Compared with younger patients, elderly patients with NTAA often have non-specific symptoms, multiple comorbidities, impaired immune function, and atypical laboratory and imaging findings, resulting in increased risks of missed or delayed diagnoses, complications, and death.^[2] Approximately 30% of elderly patients with NTAA ultimately require surgery, and delays in surgical treatment are associated with increased mortality and morbidity.^[3] As the population ages, standardized emergency management of elderly patients with NTAA has become increasingly important.

The Chinese Society of Emergency Medicine, the Emergency Medicine Branch of the Chinese Geriatrics Society, and the Emergency Medicine Branch of the Beijing Medical Association jointly initiated a consensus regarding NTAA in the elderly population that was registered on the PREPARE platform (PREPARE-2025CN1546). A systematic literature search was conducted using the terms “acute abdomen”, “acute abdominal pain”, “Geriatric”, “elderly”, “nontraffic”, and “emergency” in PubMed, MEDLINE, Embase, the Cochrane Library, CNKI, Wanfang Database, and the Full-text Database of Chinese Medical Journals from database inception to May 2026. Among a total of 492 articles initially identified, 26 were included based on the exclusion criteria. Ten key clinical questions were developed, and 13 recommendations were formulated through expert discussion, consultation, and correspondence-based voting using a Likert scale.^[4]

Question 1: What pathophysiological mechanisms contribute to the atypical presentation of NTAA in elderly patients?

Recommendation 1: NTAA in elderly patients has complex etiologies and is frequently characterized by nonspecific symptoms and physical examination findings. These are due primarily to age-related physiological decline, multiple comorbidities, and impaired immune responses.

In addition to common gastrointestinal disorders, vascular and thrombotic diseases, malignancies, and urinary tract infections are more frequent in older adults with NTAA. ^[5,6] Age-related physiological deterioration, a high incidence of chronic diseases, and impaired immune responses contribute to atypical presentations. For example, ischemic bowel disease may occur in patients with extensive vascular disease, while infections may progress rapidly to sepsis despite relatively subtle clinical manifestations.^[7]

Question 2: How should history taking and physical examination be performed?

Recommendation 2: Careful medical history and physical examination are essential, with particular attention given to vital signs and mental status. Patients with altered consciousness or shock require immediate focused assessment and emergent interventions.

Initial assessment should focus on rapid evaluation of disease severity, including vital signs, mental status, medical history, and abdominal examination.^[8] Delirium or altered consciousness may be early manifestations of severe infection, sepsis, or septic shock, which are associated with poor outcomes.^[9,10] The characteristics of abdominal pain, such as location, quality, radiation, migration, and duration, should be systematically assessed. Medical, surgical, and medication histories, particularly antithrombotic therapy, should be reviewed to identify risks of malignancy, obstruction, vascular disease, or gastrointestinal bleeding. Because physical signs may be less pronounced in elderly patients, systematic inspection, auscultation, percussion, and palpation are needed.

Question 3: Which laboratory and bedside studies should be performed promptly?

Recommendation 3: Initial evaluation should include electrocardiography and laboratory tests, including inflammatory indicators, liver and renal functions, pancreatic enzymes, myocardial ischemic markers, coagulation, D-dimer, arterial blood gas, and serum lactate.

Laboratory tests provide critical information on diagnosis, severity assessment, and treatment decision-making. Inflammatory biomarkers such as C-reactive protein, procalcitonin, and interleukin-6 may help identify infection and severe intra-abdominal disease.^[11] Blood lactate levels provide important information regarding tissue hypoperfusion and prognosis.^[12-14] Serial myocardial injury markers may help identify acute coronary syndrome that presents primarily with abdominal pain.^[15,16] Coagulation parameters and D-dimer levels may help to identify vascular disorders, including mesenteric ischemia, pulmonary embolism, and aortic dissection.^[17]

Question 4: What imaging should be performed first?

Recommendation 4: Computed tomography (CT) is the preferred imaging modality for elderly patients with NTAA. Contrast-enhanced CT or CT angiography (CTA) is recommended when vascular or intestinal pathologies are suspected after shared decision-making regarding the risks and benefits of contrast administration.

Recommendation 5: Point-of-care ultrasound (POCUS) may be used. Supine and upright abdominal radiographies remain useful for suspected intestinal obstruction or perforation and follow-up reevaluation.

CT provides broad diagnostic information with high diagnostic accuracy. It is particularly valuable when the clinical presentation is atypical. Contrast-enhanced CT and CTA are especially useful for detecting vascular lesions, ischemia, and active bleeding. POCUS is readily available and may be useful for evaluating solid organ pathologies or unstable patients. Abdominal radiography remains useful for patients with suspected bowel obstruction or perforation. Imaging should be individualized according to clinical presentations, renal and cardiac function, and the critical situation.

Question 5: How should NTAA be classified, and which causes require particular attention?

Recommendation 6: NTAA in elderly patients can be classified into infection, obstructive, vascular/thrombotic, hemorrhagic, and perforative types. Vascular/thrombotic, hemorrhagic, and perforative causes require emergent subspecialty attention because of their potentially rapid progression and lethal outcomes in elderly adults.

The causes of infection include acute cholecystitis, cholangitis, pancreatitis, appendicitis, and peritonitis. Obstructive causes include biliary stones, intestinal obstruction, adhesions, hernia, urinary calculi, and tumors. Vascular/thrombotic disorders include ischemic bowel disease, abdominal aortic aneurysm, intraabdominal vein thrombosis, and aortic dissection. Hemorrhagic causes include aneurysm rupture, tumor-related bleeding, bowel arterial bleeding, and hemorrhage from abdominal organs. Perforation is commonly associated with peptic ulcer disease, diverticulitis, foreign bodies, and gastrointestinal tumors.

Clinicians should also consider extra-abdominal diseases that may mimic acute abdomen, including acute myocardial infarction and pneumonia, as well as metabolic, neurological, endocrine, and toxic conditions. Because elderly patients may lack typical symptoms and signs, a high index of suspicion is essential.

Question 6: How should disease severity be assessed?

Recommendation 7: Serial physical examinations and close monitoring of vital signs, laboratory tests, and serial imaging are essential to evaluate the severity and predict worse outcomes.

Recommendation 8: The Sequential Organ Failure Assessment (SOFA)/quick Sequential Organ Failure Assessment (qSOFA) and modified Early Warning Score (MEWS) are recommended for initial severity assessment, followed by repeated dynamic reassessment.

Elderly patients with NTAA may deteriorate rapidly and develop shock or multiple organ dysfunction. Severity assessment should therefore not rely on a single examination or score. The Acute Physiology and Chronic Health Evaluation II (APACHE II) provides a comprehensive assessment that incorporates age, physiological abnormalities, and chronic comorbidities. It is more suitable in intensive care or inpatient settings. SOFA/qSOFA can facilitate the recognition of organ dysfunction and sepsis, whereas MEWS is relatively simple and suitable for emergency triage and early dynamic monitoring.^[18]

Question 7: What initial management should be provided?

Recommendation 9: Continuous monitoring of vital signs and organ function is critical. Appropriate fluid resuscitation and circulatory support should be provided while optimizing nutritional status and managing comorbidities and complications.

Initial management should focus on symptom control, correction of circulatory and metabolic abnormalities, and prevention of organ dysfunction. Patients with critical illness or shock require continuous cardiac monitoring, oxygen therapy, airway protection, and appropriate circulatory support. In patients with dehydration or shock, early crystalloid resuscitation is recommended, with fluid administration carefully adjusted according to the patient’s hemodynamic status, urine output, and lactate level to avoid fluid overload.^[19] Electrolyte and acid‒base abnormalities should be corrected. Fasting, antiemetic therapy, gastrointestinal decompression, and other gastrointestinal interventions should be individualized according to the suspected diagnosis. Because elderly patients are particularly vulnerable to malnutrition, early enteral nutrition should be considered if not contraindicated. ^[20] Preexisting diseases should be actively managed, and antithrombotic therapy should be individualized according to bleeding and thrombotic risks.

Question 8: How should pain be managed?

Recommendation 10: Early pain control improves patient comfort and facilitates diagnostic and therapeutic measures.^[21,22] Following analgesic administration, pain, vital signs, disease progression, and adverse effects should be continuously monitored, with regular reassessment.^[23]

Recommendation 11: Pain should be assessed using validated scales, and analgesic selection should be individualized according to pain severity, characteristics, etiology, age-related pharmacological changes, and adverse effects.

Pain should preferably be assessed using validated scales such as the Numerical Rating Scale (NRS, 0-10) or the Faces Pain Scale. Antispasmodic agents such as phloroglucinol or anisodamine may be considered for mild-to-moderate pain; opioids may be used for severe pain after adequate diagnostic assessment. Treatment efficacy and adverse reactions should be reassessed regularly (recommended every 30-60 min),^[23] particularly in patients receiving potent analgesics. Persistent or refractory pain may require multidisciplinary management.^[24]

Question 9: What are the principles of antimicrobial therapy?

Recommendation 12: In elderly patients with confirmed or suspected bacterial infection, antimicrobial therapy should be initiated promptly and individualized according to the suspected source, disease severity, microbiological characteristics, organ function, and risk of drug resistance.

Antimicrobial therapy is important for suppurative abdominal infection, gastrointestinal perforation, biliary tract infection, sepsis, and septic shock.^[25] Broad-spectrum empirical therapy may be required for severe or complicated infections, particularly when gram-negative organisms or anaerobes are suspected.

Microbiological specimens from blood, urine, stool, and drainage fluid should be obtained before treatment whenever feasible, and therapy should be subsequently adjusted according to culture and susceptibility results. Renal and hepatic dysfunction, polypharmacy, drug interactions, altered pharmacokinetics, and the need for dose adjustment or therapeutic drug monitoring should be considered.

Question 10: What is the role of multidisciplinary management?

Recommendation 13: A multidisciplinary team (MDT) is frequently required for elderly patients with NTAA. Surgical indications should be carefully evaluated, with the goals of improving prognosis and relieving symptoms.

Early consultation with relevant specialists is recommended because of multiple comorbidities and multisystem dysfunction. Emergent surgery remains a definitive treatment for many life-threatening abdominal conditions. The timing of surgery should balance the risks of delayed intervention against perioperative risks.^[26] Early consultation with gastroenterology is recommended when endoscopic intervention is indicated for gastrointestinal bleeding, peptic ulcer disease, gastrointestinal calculi, or tumors. For ischemic bowel disease, prompt vascular imaging, interventional assessment, and surgical consultation are needed. Patients with shock or multiple organ failure should be transferred promptly to the ICU. For patients with severe comorbidities or limited therapeutic options, treatment goals should be individualized, with palliative care considered when appropriate to prioritize symptom relief, dignity, and quality of life.

In conclusion, managing elderly patients with NTAA should focus on rapid stabilization, individualized fluid and organ support, appropriate analgesia, timely antimicrobial therapy when infection is suspected, nutritional support, and active management of comorbidities. Because clinical conditions may evolve rapidly, serial reassessment is essential. Early involvement of surgery, gastroenterology, interventional radiology, intensive care, and other relevant specialties can facilitate early intervention and improve outcomes. A standardized, dynamic, and multidisciplinary approach is therefore recommended for elderly patients with NTAA in emergency departments.

Funding: This study was supported by Beijing Clinical Key Specialty Project (2023) and the Beijing High-level Innovation and Entrepreneurship Talent Support Program Leading Talent Projects (20250074).

Ethical approval: Not needed.

Conflicts of interest: The authors have no competing interests.

Contributors: Study design: GQZ, CZL, YFM, MRX, WG (Wei Gu), WG (Wei Guo); literature review: WG (Wei Gu), JZ, XBP, JSY; draft of the manuscript: WG (Wei Gu), JZ XBP, JSY.