Antibiotics for Delirium in Older Adults With No Clear Urinary Tract Infection (A-DONUT)

Delirium is an acute confusional state that is experienced by many older adults who are admitted to hospital. To treat delirium the underlying cause needs to be identified promptly, but this is challenging. One of the potential causes of delirium is infection. Urine tests show that most patients experiencing delirium have bacteria in their urine, however, bacteria in the urine is common among older adults, and does not automatically indicate an infection is present. As a result it is difficult to know whether a lower urinary tract infection is present as individuals with delirium are frequently unable to report clinical signs of infection - symptoms of pain or discomfort with urination, having to urinate more frequently or pelvic discomfort. Very often, individuals with delirium are treated with antibiotics despite the fact that it is unknown whether antibiotics help to improve delirium in cases where bacteria in the urine is present. This proposed study is a randomized controlled trial that will examine if adults (age 60 or older) with delirium and suspected infection benefit from taking antibiotics.

Participants will be randomized to start or continue with antibiotics. Antibiotic type and duration targeted to lower urinary tract infection as directed by the Most Responsible Physician (MRP).

Participants will be randomized to start or continue with antibiotics (with antibiotic duration determined by the Most Responsible Physician [MRP]). Antibiotics choice to be selected by the MRP.

Delirium will be assessed using Confusion Assessment Method (CAM) or 4 A's Test (4AT). CAM assesses 4 delirium features: [1] inattention, [2] acute and fluctuating level of consciousness, [3] disorganized thinking and [4] altered mental status. For a diagnosis of delirium by CAM, the patient must display feature [1] AND [2], AND EITHER [3] or [4]. The 4AT is scored from 0-12. A score of 4 or more suggests delirium.

C. difficile will be defined as a combination of a positive microbiological test for C. difficile (if still hospitalized at the time of diagnosis), or self-reported diagnosis of C. difficile (provided the patient reported diarrhea and receipt of an antibiotic to treat C. difficile)

Inclusion criteria Age ≥ 60 and admitted to a hospital ward (including rehabilitation hospital); Active delirium (defined by CAM: [1] inattention AND [2] acute and fluctuating level of consciousness, and either [3] disorganized thinking OR [4] altered mental status; or defined by the 4AT score [www.the4at.com/]) OR physician's diagnosis Less than 24 hours of antibiotics (prior to trial assessment) Either pyuria (defined as white blood cells detected on urinalysis or dipstick) or bacteriuria (defined as bacteria growing on urine culture) Exclusion criteria Fever (temperature > 37.9C or > 100.2F) in the past 48 hours; Signs of lower urinary tract infection symptoms (such as new dysuria) or upper urinary symptoms (such as costovertebral tenderness) In the opinion of the treating physician, there is a reason apart from delirium and urine test results to treat with antibiotics (e.g., pneumonia) Indwelling urinary catheter for > 72 hours