From the Guidelines
Bleeding is caused by a combination of factors, including ongoing bleeding, low systolic blood pressure, elevated prothrombin time, erratic mental status, and unstable comorbid disease, as outlined in the BLEED classification system 1. The causes of bleeding can be complex and multifaceted, involving various physiological and pathological processes.
- Ongoing bleeding can lead to hypovolemic shock, which can further exacerbate the bleeding due to decreased blood pressure and perfusion of vital organs.
- Low systolic blood pressure can indicate hypovolemia or cardiogenic shock, both of which can contribute to bleeding.
- Elevated prothrombin time can indicate coagulopathy, which can increase the risk of bleeding.
- Erratic mental status can be a sign of hypoxia or shock, which can impair the body's natural clotting mechanisms.
- Unstable comorbid disease can increase the risk of bleeding due to underlying conditions such as liver disease, renal failure, or cancer.
The BLEED classification system has been proposed as a means of triaging patients with acute lower gastrointestinal bleeding into those at high risk and those at low risk of adverse in-hospital outcome, including recurrent hemorrhage, need for surgery to control hemorrhage, and death 1.
- A study published in 2005 found that the BLEED classification system could predict outcome in patients hospitalized with acute lower gastrointestinal bleeding when applied at the point of initial evaluation in the emergency department 1.
- Another study published in 2007 found that massive bleeding in trauma patients is often caused by a combination of vascular injury and coagulopathy, and that early identification of potential bleeding sources and prompt action to minimize blood loss are crucial in managing bleeding 1.
- A more recent study published in 2021 found that systemic therapies, including tranexamic acid and bevacizumab, can be effective in managing GI bleeding in patients with hereditary hemorrhagic telangiectasia 1.
In terms of management, it is essential to prioritize the patient's airway, breathing, and circulation (ABCs) and to address any underlying causes of bleeding.
- Applying direct pressure to the wound, elevating the injured area above heart level, and administering fluid resuscitation can help control bleeding.
- In cases of severe bleeding, surgical or radiological interventions may be necessary to control the bleeding source.
- Systemic therapies, such as tranexamic acid and bevacizumab, can be effective in managing GI bleeding in certain patient populations 1.
From the FDA Drug Label
• Patients with congenital hemophilia receiving concomitant treatment with aPCCs (activated prothrombin complex concentrates), older patients particularly with acquired hemophilia and receiving other hemostatic agents, or patients with a history of cardiac, vascular disease or predisposed to thrombotic events may have an increased risk of developing thrombotic events The causes of bleeding are not directly stated in the provided drug labels. However, it can be inferred that thrombotic events and hypersensitivity reactions may be related to bleeding, but the labels do not provide a clear answer to the question of what causes bleeding [ 2 ].
From the Research
Causes of Bleeding (BLEED)
The provided studies do not directly address the causes of bleeding. However, they discuss various contexts in which bleeding occurs, such as:
- Traumatic bleeding 3, 4, 5
- Surgical bleeding 3, 6
- Postpartum haemorrhage 3, 4
- Upper gastro-intestinal haemorrhage 3
- Palliative care patients with advanced cancer 7
- Spontaneous intracerebral hemorrhage 4
- Gastrointestinal bleeding 4
Risk Factors for Bleeding
Some studies mention risk factors for bleeding, including:
- Trauma 3, 4, 5
- Surgery 3, 6
- Cancer 7
- Hyperfibrinolysis 6
- Polytrauma 6
- Surgical procedures involving organs rich in plasminogen proactivators (e.g. liver, kidney, pancreas, uterus, and prostate gland) 6
Mechanisms of Bleeding
The studies also discuss mechanisms of bleeding, such as: