Diagnostic Tests for Occult Bleeding
| Diagnostic Test | Purpose/Considerations |
|---|---|
| Hemoglobin and hematocrit levels | Essential for ongoing assessment. Results are unreliable during or immediately after acute hemorrhage—levels may not accurately reflect early blood loss. Low baseline levels may indicate pre-existing anemia. |
| A coagulation profile | Detects actual or potential abnormalities, especially in a patient taking an anticoagulant or drugs that affect platelet function. Factor assay may reveal clotting disorders such as hemophilia, low platelet count or elevated prothrombin time, activated partial thromboplastin time, or international normalized ratio indicating coagulopathy. |
| Serum lactate level and arterial blood gases | Evaluate tissue perfusion. A rising lactate level signals insufficient perfusion. An arterial pH less than 7.35 and a falling bicarbonate level indicate impaired perfusion and metabolic acidosis. |
| CT scan | May suggest fluid collections or injury to solid organs; free fluid may indicate bleeding into organs or spaces. |
| X-rays | May reveal fluid in the thorax or hemothorax, aortic injury, pelvic fracture, or fracture of other large bones, such as the femur, which can cause significant blood loss. |
| Arteriography | Helps detect arterial disruption caused by trauma or vascular abnormality. It may be used to guide injection of a clot-forming substance into the bleeding vessel. Aortic imaging helps rule out traumatic disruption or dissecting thoracic aneurysm. |
| Ultrasound | Helps detect bleeding in the peritoneal cavity, thorax, pericardium, retroperitoneum, pelvis, or uterus. It permits simultaneous procedures, such as placing IV lines or an endotracheal tube. |
| Endoscopy | Allows visualization of a gastrointestinal bleeding source and may allow the physician to sclerose bleeders. |
| Diagnostic peritoneal lavage | May be performed at the bedside to rapidly identify intraperitoneal hemorrhage in an unstable or critical patient. It does not identify retroperitoneal bleeding or pinpoint hemorrhage site. If results are positive, the patient may require laparotomy. |
| Laparoscopy | May help rule out intra-abdominal hemorrhage. It is not appropriate for acute hemorrhage because setup is time-consuming and surgical access is limited. |
| Transesophageal echocardiography | May be performed at the bedside to detect cardiac injury, such as aortic dissection. It is contraindicated in esophageal trauma. |
SOURCE: Used with permission from Nursing 97, 27(9):38, © Springhouse Corporation/Springnet.com.