From the Guidelines
A CT abdomen pelvis with intravenous contrast is recommended for patients with lactic acidosis when there is suspicion of intra-abdominal pathology, such as mesenteric ischemia, as it can help identify the underlying cause and guide management. Lactic acidosis itself is not a direct indication for CT imaging, but rather a laboratory finding that suggests tissue hypoperfusion or hypoxia 1. The presence of lactic acidosis in combination with abdominal pain, even in patients who may not otherwise appear clinically ill, should lead to consideration for early computed tomography angiography (CTA) 1.
Key Considerations
- The clinical context and suspected underlying cause of lactic acidosis are crucial in deciding whether to perform a CT abdomen pelvis.
- CT abdomen pelvis would be appropriate if there's suspicion of intra-abdominal pathology causing the lactic acidosis, such as mesenteric ischemia, bowel obstruction, intra-abdominal infection, or malignancy.
- Patients with abdominal pain, distension, peritoneal signs, or unexplained lactic acidosis without an obvious cause (like sepsis or cardiogenic shock) would benefit from imaging.
- CT with intravenous contrast is typically preferred to evaluate vascular structures and enhance tissue differentiation, unless contraindicated by renal dysfunction 1.
Diagnostic Approach
- Computed tomography angiography (CTA) should be performed as soon as possible for any patient with suspicion for acute mesenteric ischemia (AMI) 1.
- Comprehensive biphasic CTA includes pre-contrast scans, arterial and venous phases, and multi-planar reconstructions (MPR) to assess the origin of the mesenteric arteries and detect signs of ischemia or infarction 1.
- While addressing the underlying cause of lactic acidosis, it's also important to simultaneously initiate resuscitative measures including fluid administration and hemodynamic support, as lactic acidosis often indicates a critical illness requiring prompt intervention.
From the Research
Indications for CT Abdomen Pelvis in Lactic Acidosis
- Lactic acidosis can be caused by various conditions, including mesenteric ischemia, lymphoma, and short bowel syndrome 2, 3, 4.
- A CT scan of the abdomen and pelvis can be useful in diagnosing these conditions, especially when the cause of lactic acidosis is unclear 3, 5.
- In cases of suspected mesenteric ischemia, a CT scan with IV contrast can help identify findings such as pneumatosis and enterocolitis 5.
- For patients with short bowel syndrome, a CT scan may not be necessary for the diagnosis of D-lactic acidosis, but it can help rule out other causes of abdominal symptoms 4, 6.
Specific Considerations
- In critically ill patients with unexplained lactic acidosis, diagnostic laparoscopy may be a useful investigation to avoid unnecessary emergency laparotomy 2.
- A CT scan of the abdomen and pelvis can be performed with or without contrast, depending on the patient's renal function and other factors 5.
- The presence of normal serum lactate does not rule out the possibility of acute mesenteric ischemia, and a CT scan may still be necessary for diagnosis 5.
Summary of Evidence
- The use of CT abdomen pelvis in patients with lactic acidosis is supported by several studies, including 2, 3, 5.
- The choice of imaging modality and the need for contrast depend on the individual patient's condition and the suspected cause of lactic acidosis 5.
- Diagnostic laparoscopy may be a useful alternative to CT scan in certain cases, such as critically ill patients with unexplained lactic acidosis 2.