What investigations could help establish a diagnosis?

From the Guidelines

To establish a diagnosis, a thorough history and physical examination should be followed by laboratory tests including complete blood count, serum creatinine, and inflammatory markers such as C-reactive protein, procalcitonin, and lactates, as suggested by the most recent guidelines 1. When suspecting a complicated rectal prolapse, it is essential to assess the patient's status through these laboratory tests to guide further management.

• A complete blood count can help identify signs of infection or inflammation.
• Serum creatinine levels can assess renal function, which may be compromised in severe cases.
• Inflammatory markers like C-reactive protein, procalcitonin, and lactates are crucial for evaluating the severity of the condition and potential complications such as bowel ischemia or necrosis 1. Additionally, considering the patient's presentation and potential for other conditions, imaging studies like CT scans may be necessary for a definitive diagnosis, especially in cases where the clinical examination is not conclusive or when there's a suspicion of complications 1.
• For patients with suspected intra-abdominal infections or complications, a contrast-enhanced CT scan is recommended for its high reliability in diagnosing intrabdominal disease 1.
• In immunocompromised patients, where clinical signs may not be reliable, a combination of history, symptoms, and imaging evaluation is crucial for a reliable diagnosis, with a contrast-enhanced CT scan being the most reliable exam when feasible 1. It's also important to consider specific tests based on the patient's symptoms and history, such as a test for Clostridioides difficile in cases of diarrhea, and to adjust the diagnostic workup according to the patient's immune status and potential for specific diseases associated with their condition 1.

From the FDA Drug Label

In patients treated with CEFTRIAXONE FOR INJECTION the Coombs' test may become positive. CEFTRIAXONE, like other antibacterial drugs, may result in positive test results for galactosemia. Nonenzymatic methods for the glucose determination in urine may give false-positive results For this reason, urine-glucose determination during therapy with Ceftriaxone for injection should be done enzymatically. The presence of ceftriaxone may falsely lower estimated blood glucose values obtained with some blood glucose monitoring systems.

The following investigations could help establish a diagnosis:

• Coombs' test to check for positive results
• Urine-glucose determination using enzymatic methods
• Blood glucose monitoring using alternative testing methods if necessary
• Galactosemia tests to rule out false-positive results 2
• Imaging studies such as sonography to detect sonographic abnormalities, e.g., in the urinary tract or gallbladder 2
• Blood tests to monitor for adverse reactions, e.g., elevated liver enzymes, blood creatinine, or bilirubin 2

From the Research

Investigations to Establish a Diagnosis

To establish a diagnosis, several investigations can be helpful. These include:

• Physical examination: A valuable tool in the outpatient setting, the physical examination can help narrow down or establish a diagnosis, especially when combined with a thorough history 3.
• Laboratory tests: Such as a complete blood cell count (CBC), which can be a powerful diagnostic tool when used in conjunction with a good history and physical examination 4.
• Imaging tests: Although not specifically mentioned in the studies, imaging tests can be useful in certain cases, but are often expensive and invasive 3.
• History-taking: The medical history is a crucial component of diagnosis, with studies showing that it leads to diagnosis in a significant percentage of cases 5, 6, 7.

Relative Contributions of Investigations

The relative contributions of history-taking, physical examination, and laboratory investigation to diagnosis and management of medical outpatients have been studied. The results show that:

• History-taking is the most important component, leading to diagnosis in 66-78% of cases 5, 6, 7.
• Physical examination is useful in a smaller percentage of cases, around 8-12% 5, 6.
• Laboratory investigations are also important, but lead to diagnosis in a smaller percentage of cases, around 11-13% 5, 6.
• The combination of history-taking, physical examination, and laboratory investigation is often necessary to establish a diagnosis, with each component having its own limitations 5, 6, 7.