Fevers Of Unknown Origin - Its Effects And Treatments In Dialysis Patients
Dialysis patients are susceptible to a variety of fevers of unknown origin (FUO). Fever should be diagnosed and treated as soon as possible by doctors.
Fever is a symptom that doctors see a lot in dialysis patients. Fever can be associated with a variety of diseases, including infectious diseases, cancer, and allergies.
Infectious diseases can become severe and even fatal in dialysis patients because their immune systems are weakened due to aging or diabetes complications.
The application of necessary treatments will be delayed if the cause of fever is assumed to be an infection. As a result, doctors should figure out what's causing the fever and begin treating patients as soon as possible.
Fever of unknown origin (FUO) is a clinical condition that can be caused by a number of factors. Its most distinguishing feature is a fever that does not go away on its own, lasts longer than a typical infectious disease, and has no known cause despite routine investigations.
The following are the criteria for FUO, according to a report by Petersdorf and Beeson published in 1961:
- Undiagnosed after 1 week of inpatient examination
- A temperature higher than 38.3 oC on several occasions
- A duration of fever ≥3 weeks
Infectious diseases, malignancies, and connective tissue diseases are all common causes of fever in non-dialysis patients. Because dialysis patients use shunts and catheters, have an immune system weakened by diabetes complications or the use of steroids, and have regular dialysis sessions, a variety of causes of fever are considered in dialysis patients.
In dialysis patients, infection is the most common cause of fever; infections of the respiratory system, dialysis access site, and urinary tract are particularly common. The bacteria that cause the problem range from gram-positive to gram-negative. Because dialysis patients have a weakened immune system, infections such as methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and pathogenic fungi can cause infection and fever.
Tuberculosis should also be taken into account. Dialysis patients have a higher prevalence of extrapulmonary tuberculosis (military tuberculosis, lymph nodes, kidneys, urinary tract, and pleura) than healthy people. The tuberculosis bacterium is rarely detected in dialysis patients, and the percentage of those who have a positive tuberculin skin test result is low, making a definitive diagnosis difficult.
Patients on hemodialysis use a vascular access for dialysis, so access-related infections should be avoided. Pathogens can also infect haemodialysis patients through the artificial blood vessel or the puncture or insertion site of the dialysis catheter. Exit-site and tunnel infections in a peritoneal dialysis catheter can cause peritonitis in peritoneal dialysis patients.
Because many dialysis patients have malignancies in the digestive and urinary organs, malignancy-associated fever should be treated with caution. Abdominal ultrasonography or computed tomography (CT) are increasingly being used to detect renal cancers rather than waiting for symptoms like haematuria and low back pain to appear. Fever can also be caused by blood tumors like malignant lymphoma or leukemia.
Patients on hemodialysis may develop a fever as a result of an allergic reaction to a dialysis circuit. Dialysis-related items such as dialysis membranes, dialysis circuits, puncture needles, anticoagulants, and endotoxin should therefore be investigated. Because fever can occur in conjunction with dialysis, the time course of the fever should be examined. Allergies to the materials used in dialysis devices and contaminants (endotoxins) in the dialysate are the main pathogenic mechanisms underlying the development of dialysis-related fever.
When the cause of the fever is determined, the proper treatment strategy can be implemented right away. When the cause of a fever is unknown, the diagnosis should be made based on the urgency of treatment and the FUO classification of Durack and Street. The clinical history of the patient should be thoroughly examined first.
The onset and duration of fever, the location of the cause of fever (inside or outside the hospital), the use of artificial materials (catheters and artificial blood vessels), possible causes of a decrease in neutrophil count, and the risk of HIV infection, for example, should all be investigated. Interviewing patients about their travel history, living environment, the presence or absence of people in close contact with them who have a similar symptom, regular medication, and pet ownership is also beneficial.
Then, to track the changes in patients over time, repeated physical examinations should be performed. A close examination of the skin around the blood access of haemodialysis patients and the catheter of peritoneal dialysis patients is required in addition to the general physical findings.
Physicians should not order examinations on a whim, but rather anticipate the possible diagnosis based on the examination results before placing the order. Patients with an allergy to the materials used in dialysis devices may see an increase in their eosinophil count and IgE level, but increases in white blood cell count and C-reactive protein (CRP) are uncommon when such patients are free of infections. In patients with a fever, contaminants such as endotoxins may cause an increase in white blood cell count and CRP level.
In general, FUO treatment in dialysis patients should begin once the cause of FUO has been identified. Early administration of antibacterial drugs should be avoided. Most cases of fever, including those caused by viral infection, resolve as self-limited diseases during the follow-up period when patients do not require immediate medical attention and are in good health. This natural resolution has a duration of 3 weeks, which corresponds to the definition of classic FUO.
This three-week course, however, may not be applicable to all patients. Before establishing a definite diagnosis, empiric therapy should be started when symptoms rapidly worsen and become serious. Identifying the causative bacterium and treating it with an antibacterial drug is a simple method.
A broad-spectrum antibacterial drug should be used in immunocompromised hosts. Septicemia, neutropenic FUO, and severe infectious diseases (infectious endocarditis, intraabdominal abscess, and pneumonia) are all conditions that require immediate medical attention. When a foreign object, such as a dialysis catheter, is suspected of causing a fever, it should be removed.
According to the Hemodialysis (HEMO) Study, a catheter was used as the vascular access for dialysis by 7.6% of all study patients, and 32% of study patients admitted with an access-related infection used a catheter. According to another study, haemodialysis patients who used a catheter had a threefold higher risk of infection-related death than those who used an arteriovenous fistula. If tuberculosis infection is suspected, empiric treatment may be sufficient before a definitive diagnosis is established.
If an allergy to the materials used in dialysis devices is suspected, the materials of the dialysis devices and the sterilization method should be examined to determine the cause of the fever and, if necessary, the device should be replaced with one made of different materials or using a different method. If a dialysis membrane is suspected of being the source of a fever, it should be replaced with one that is more biocompatible. If there are contaminants in the dialysate, it should be purified more thoroughly and an endotoxin-retentive filter installed.
The use of a steroid or an immunosuppressant for connective tissue diseases is generally effective. Following the determination of the site and stage of the malignancy, surgery or chemical therapy should be used to treat it.
Fever in dialysis patients is typically caused by common respiratory or digestive infections, but when fever is accompanied by chills during dialysis sessions, an endovascular infection should be suspected. Fever is occasionally linked to autoimmune diseases or cancerous tumors.
Three types of infection: 1) of the bronchopulmonary system, 2) of the urinary tract, and 3) access related infections are the most common causes of fever in dialysis patients (regardless of reuse or dialysis procedure). These "big three" are responsible for the vast majority of fevers in dialysis patients.
Exit-site infections, tunnel infections, and catheter-related bacteremia (CRB) are all associated with the use of tunneled dialysis catheters.
Hemodialysis patients are at a high risk for infection because the process of hemodialysis requires frequent use of catheters or insertion of needles to access the bloodstream.
Although there are several causes of fever of unknown origin in dialysis patients, early administration of an antibacterial drug or steroid before a definitive diagnosis of the primary disease should be avoided because it delays accurate diagnosis.
Infectious diseases caused by in-hospital infection or complicated by neutropenic FUO, on the other hand, should be treated as soon as possible because they can become serious if not treated promptly. Dialysis patients with FUO need to know what causes their fevers and how to treat them based on the severity of their symptoms.