During a urodynamics study (UDS), there are a variety of pieces of data coming in to the urologist and technician performing the study. Information will be obtained that is both subjective and objective in nature and the question is, who do you believe? Do you believe yourself and the objective data you are reviewing? Or, do you believe what the patient is telling you during the study? This blog post will explore this in detail.
In a typical UDS study, it is important to remember what data you are collecting from objective measures and what is the patient reporting. Objective measures will include capacity, compliance, overactivity, voiding time, pressure when voiding and residual urine. Subjective data will include first sensation, strong sensation, very strong sensation/sense of being at capacity and subjective assessments of how empty the patient is. Both sources of data are helpful and need to be considered.
Patient reported data such as first sensation and degree of urge are critical data. Patients with a hypersensitive bladder may report very early sense of being close to capacity, while the UDS is showing a normal capacity. Such data is critical to counseling the patient and such patients often do very well with behavioral interventions or modifications. Likewise, patients may report a sense of urge and have no UDS correlate – upwards of half of patients with overactive bladder do not demonstrate detrusor overactivity in the lab during UDS. In such cases, the subjective data is critical to understanding the patient’s complaint and formulating a treatment plan.
During the voiding phase of the test, the patient’s subjective input is less crucial. Whether or not the patient voids and what the pressures are is generally an objective measure. That being said, patients who sense the bladder is still full when it is, in fact, empty are likewise patients who will do well with counseling that they are in fact showing normal physiology. Likewise, the patient who cannot void and is clearly feeling a desire to urinate and subjectively providing the examiner feedback is giving the urologist excellent data to coordinate a care plan.
As with many aspects of medicine, a combination of subjective and objective data is critical to get the right diagnosis and treatment plan. When it comes to UDS, a mix of subjective data from the patient and objective data from the test is often the optimal means of using UDS to get the best possible outcomes. Subjective data often is very useful for the filling cystometry, especially regarding urgency. Objective data is often most useful during the voiding phase of the test.