Patients presenting with acute abdominal symptoms offer a common and difficult challenge for emergency physicians.
Acute abdominal pain is a common symptom (8% of adults) that motivates consultation to the emergency services. Few patients require urgent surgical treatment, and in many, a clear etiology is not found to justify their symptoms.
The differential diagnoses are many, from immediately life-threatening conditions to physical manifestations of acute psychological distress.
Although knowledge about common conditions such as biliary disease, appendicitis, and diverticular disease is important, emergency physicians need to know how to initiate screening and treatment. Stratify patients into appropriate emergency pathways.
| Patient groups |
Patients with a possible acute abdomen are divided into 4 groups:
• Those who are obviously wrong.
• Those with symptoms, signs and basic studies that suggest the need for possible urgent active treatment to control the pathology and thus prevent disease progression, e.g., acute appendicitis, intestinal obstruction and diverticulitis.
• Those with a reassuring clinical picture, which suggests a greater likelihood of spontaneous resolution with simple symptom support.
• Those with symptoms secondary to non-abdominal conditions, such as heart pain, pneumonia, costochondritis, low back pain, shingles, etc.
| The dilemma: not promptly initiating appropriate care and referral vs. excessive research |
Patients undergoing emergency laparotomy for acute abdominal pain have high mortality rates (9.6%). In recent years, the National Emergency Laparotomy Audit (NELA) has conducted a detailed review of this group of patients.
This audit has shown that, despite improvements, perioperative care remains suboptimal.
- Fluid resuscitation is poor, leading to risks related to acute kidney injury.
- In individuals with sepsis, antibiotic therapy is started late (6% did not receive antibiotics within 1 hour).
- Definitive images and reports often arrive late, and timely and expert surgery was also delayed in 25% of the most seriously ill patients.
- Furthermore, access to specialized surgical, anesthetic, critical and geriatric care remains poor.
It has been clearly established that delay in starting definitive treatments for patients with sepsis and/or shock significantly worsens the prognosis.
Treatment of shock, initiation of antibiotics, and control of the source of shock require urgent care (within hours).
Excessive research creates risks and uses resources that are limited. Although often very reassuring, this can increase long-term anxiety levels in patients who suffer from recurrent episodes of acute abdominal pain:
On the other hand, computed tomography (CT), which is the definitive acute abdominal imaging modality in adults, carries risks related to radiation exposure. We must also consider the additional burden of investigation and management related to ’ incidentalomas ’ that appear in 5% of examinations.
| Initial clinical care of patients with acute abdomen, for non-surgeon emergency physicians |
Perform adequate resuscitation with fluids, oxygen, and inotropes. Regarding fluids, clinicians must catch up and maintain adequate water and electrolyte therapy.
A patient with acute abdominal illness might have been fasting for days, had abnormal bowel losses, and was losing fluid into the inflammatory third space. The resuscitation volume is usually inadequate.
Relieve distress. Patients almost always have moderate to severe pain. There is clear evidence that timely and adequate administration of analgesics does not delay diagnosis. The traditional practice of delaying opioid analgesia until further surgical evaluation by the surgeon is inappropriate.
Ensure early administration of antibiotics in patients at high risk of sepsis. In the UK, antibiotics are given for conditions such as uncomplicated diverticulitis and cholecystitis. There is little evidence to support this practice, while other European countries avoid administering antibiotics in these diseases. If in doubt, the emergency doctor should start broad-spectrum antibiotics, which can always be stopped once the diagnosis is clearer.
Establish the level of clinical priority and organize imaging and timely referral to the specialist. If the patient needs an emergency laparotomy, NELA recommends a CT scan within 2 hours.
Avoid giving detailed advice to the patient and their families about diagnoses and treatments. Therapeutic options for acute abdominal conditions are complex and, even in common conditions such as appendicitis and perforated diverticulitis, surgical and non-surgical treatment options are now considered.
In this regard, the author says: “Do not tell the patient that he has appendicitis and needs an operation! Tell him that he may have appendicitis and that you will seek the surgeon’s opinion.”
| Groups of patients with acute abdomen |
> “Obviously sick” patients. Identifying a patient as clearly ill is a fundamental skill of doctors. General behavior, level of consciousness, hemodynamic parameters, temperature, and markers of ineffective perfusion (serum lactate concentration and acidosis) will be evaluated.
Most patients with acute abdominal pathology have abdominal pain. Occasionally, patients present in profound shock or are unable to provide a medical history. In patients with an acute abdomen accompanied by hemorrhagic shock or septic shock, the causative pathology should be investigated.
> Hemorrhagic shock and acute abdomen
Patients with abdominal pain and signs of hemorrhage (paleness, tachycardia, hypotension, peripheral coldness) may have intraperitoneal, abdominal wall, or retroperitoneal hemorrhage. These hemorrhages can be caused by a series of pathologies that affect a wide age group.
The clinical history helps to make an adequate treatment plan, taking into account:
• Recent trauma, including surgery, radiology and endoscopy.
• Recent intra-abdominal inflammatory processes such as acute pancreatitis, which can cause the formation of a pseudoaneurysm.
• Pregnancy (ectopic), anticoagulant and antiplatelet therapy, or an anticoagulant disorder.
• Known aneurysm of the aortic or iliac arteries.
• Infectious mononucleosis or malaria, which can cause massive splenomegaly.
> Diagnosis and treatment
In many patients, the bleeding stops spontaneously. Intraperitoneal, abdominal wall, and retroperitoneal hemorrhage may be the cause of an acute abdomen in a hemodynamically stable patient.
The key to controlling active bleeding is replacement of blood and clotting factors, reversal of anticoagulation, and control of the source of bleeding.
Critically unstable patients may require immediate surgery.
Patients with a probable ectopic pregnancy should undergo an ultrasound to establish whether the pregnancy is intrauterine or extrauterine. Otherwise, the mainstay for diagnosis and treatment planning is CT angiography.
Bleeding can be controlled by:
• Management of coagulation disorders.
• Interventional radiology (stent, embolization).
• Surgical vascular control.
> Non-hemorrhagic shock and septic shock
Some patients have a brief history of pain and feel unwell quickly (hours). Others have a longer history before feeling significantly unwell. Many abdominal pathologies, if left untreated, can lead to septic shock. It is remembered that patients with shock
Caused, for example, by heart failure, they may develop abdominal pain due to progressive organic ischemia.
Emergency physicians should provide the following care to these patients:
• Treat shock with fluids, oxygen therapy and, if necessary, inotropes.
• Start broad spectrum antibiotics.
• Take baseline blood samples to evaluate: inflammation, anemia, acute renal failure, acidosis, serum lactate and amylase concentrations, urosepsis, and pregnancy.
• Early referral to Surgery.
• Request quick images. CT with intravenous contrast gives the highest diagnostic yield. If the patient has acute kidney injury, early fluid therapy and consultation with the intensive care, surgical, and radiology teams about the risks and benefits of contrast-enhanced CT are important.
• Consider the possibility of acute bowel or ovarian ischemia, caused by thromboembolism, torsion, volvulus, or constriction.
In patients with a short history (few hours) and a presumptive diagnosis of acute vascular occlusion, urgent surgical reperfusion, interventional radiology and/or anticoagulation are necessary, which can reduce organ loss.
> Lactate and acute abdomen
Acidosis and elevated blood lactate concentration are markers of possible critical organ ischemia.
An acute abdomen and increased lactate are not diagnostic of intestinal ischemia/infarction but do require immediate resuscitation and surgical referral. Equally important, an acute abdomen with a normal lactate value does not exclude critical segmental intestinal ischemia.
> Patient in good condition with acute abdominal pain
To carry out a specialized clinical evaluation, great knowledge and experience of the natural history of acute abdominal processes is required. This is a specialized skill and is not within the domain of general emergency physicians, but they need to have a broad understanding of common diseases.
Most patients with acute abdominal pain at presentation are not critically ill.
Many acute abdominal diseases are self-limiting (90% of gallstones or ureteral stones pass without active treatment; small bowel obstruction often resolves). If patients are well, symptom management and waiting are usually appropriate. However, the development of acute inflammation should raise alarm and lead to early referral:
Patients may have a pathology that, if not treated properly, will lead to worsening of the disease or delayed recovery.
| Key red flags in the evaluation of patients with acute abdomen who are clinically well |
• Does the patient have a localized or generalized peritoneal reaction? (pain worsens with movement, true tenderness, tenderness, guarding)
• Is there an inflammatory response developing? (pyrexia, leukocytosis and, if symptoms last more than 24 hours, elevated C-reactive protein)
To plan the treatment, a clinical evaluation will be done with anamnesis, semiology, blood samples for analysis and X-ray images. The number of options for care is limited:
• Emergency or urgent surgical intervention is needed.
• The patient has a condition that requires antibiotic therapy, awaiting resolution but with the intention of performing a periodic clinical review.
• The doctor can reassure, treat symptoms, and discharge the patient without active follow-up.
• An active look, wait and active review, (traditionally in hospitalized patients, but currently, it is usually done in an outpatient “warm bed clinic”).
• Enhanced imaging ꟷCT, ultrasound, MRIꟷ can be arranged to assist in planning. Clarity is required regarding the level of urgency and purpose of the scan.
The ability to make an accurate clinical diagnosis without the aid of enhanced imaging is useful but the results are often erroneous.
For example, the diagnosis of appendicitis is difficult and clinical evaluation gives false negative (late treatment) and false positive (unnecessary operation) results. The growing trend toward using enhanced imaging modalities is now accepted as improving diagnostic accuracy, and even experienced emergency surgeons are increasingly seeing the benefits.
