Related Experiment Video
Updated: May 22, 2026

Doppler Ultrasound-Based Leg Blood Flow Assessment During Single-Leg Knee-Extensor Exercise in an Uncontrolled Setting
Published on: December 15, 2023
Reliability measures in managing GI bleeding
1Portland VA Medical Center and Oregon Health & Science University, Portland, OR 97239, USA.
Background:
Multiple procedures and devices are used in a complex interplay to diagnose and treat GI bleeding.
Objective:
To model how a large variety of diagnostic and therapeutic components interact in the successful management of GI bleeding.
Design:
The analysis uses the concept of reliability block diagrams from probability theory to model management outcome. Separate components of the management process are arranged in a serial or parallel fashion. If the outcome depends on the function of each component individually, such components are modeled to be arranged in series. If components complement each other and can mutually compensate for each of their failures, such components are arranged in a parallel fashion.
Setting:
General endoscopy practice.
Patients:
Patients with GI bleeding of unknown etiology.
Interventions:
All available endoscopic and radiographic means to diagnose and treat GI bleeding.
Main Outcome Measurements:
Process reliability in achieving hemostasis.
Results:
Serial arrangements tend to reduce process reliability, whereas parallel arrangements increase it. Whenever possible, serial components should be bridged and complemented by additional alternative (parallel) routes of operation. Parallel components with low individual reliability can still contribute to overall process reliability as long as they function independently of other pre-existing alternatives.
Limitations:
Probability of success associated with individual components is partly unknown.
Conclusions:
Modeling management of GI bleeding by a reliability block diagram provides a useful tool in assessing the impact of individual endoscopic techniques and administrative structures on the overall outcome.
Related Concept Videos
Esophageal Varices-II: Clinical Features and Management
In the initial assessment, a thorough review of the patient's medical history is vital to identify risk factors such as liver disease, alcohol abuse, or...
Assessment of the Gastrointestinal System I: Subjective Data
Health History
The initial step in assessing the GI system is obtaining a comprehensive health history. This includes inquiring about the patient's history or presence of problems related to...
Errors occurring during blood pressure monitoring
Several factors...
Gastritis III: Clinical Manifestations and Management
Clinical manifestations of acute gastritis
The patient with acute gastritis may have a rapid onset of symptoms, such as epigastric pain or discomfort, dyspepsia, anorexia, hiccups, or nausea and vomiting, which can last from a few hours to a few days. Erosive or hemorrhagic gastritis may cause bleeding, which may manifest as blood in vomit or as...
Lower GI Series: Barium Enema
Procedure Details
The examination begins by inserting a lubricated rectal tube into the patient's rectum to administer a radiopaque barium solution. The barium flow is carefully...
Gastroesophageal Reflux Disease II: Clinical Features and Management
Clinical Manifestations
GERD presents itself in a multitude of ways, with symptoms varying from person to person. The hallmark symptoms are...