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2. The Lower Urinary Tract Symptoms
Keywords
HesitancyDribblingUrgencyIncreased daytime frequencyNocturiaNocturnal polyuriaIncontinenceEnuresis2.1 Introduction
In recent years, the medical professions have become increasingly focused on the subjective symptoms of patients and on patient complaints and less focused on the pathophysiological aspects of the disease. In this chapter, we scrutinize each of the lower urinary tract symptoms individually, in order to gain familiarity with how they present and what they can indicate about causative mechanism. Crucially, each symptom has two key aspects: severity and bother. The severity indicates how bad the problem appears to be, while the bother is the patient’s attitude towards it. It is natural to assume that high severity equates to high level of bother, but this is actually often not the case. For example, men can report a very slow stream, but actually not be too bothered by it. In contrast, a post-micturition dribble may look trivial (a stain the size of a small coin), but to some patients it is a substantial problem. Severity and bother are highly individual.
Across the range of symptoms, quality of life (QoL) will be affected by the bother the LUTS bring. This is a complex relationship, as someone with a bad condition-specific QoL might be reflecting bother from all the symptoms, or it may be that only one of the symptoms is bothersome enough to affect QoL. The healthcare professional (HCP) must establish which of the possible symptoms is actually driving QoL impact to ensure treatment is tailored appropriately. For example, many men are badly affected by nocturia. When assessed by the HCP, direct questioning might elicit that he has a slow urinary stream. The HCP unwisely then might divert treatment attention to the easy-to-treat LUTS, and suggest a TURP. The man might assume the HCP has appreciated that what really matters to him is the nocturia, and that the TURP is intended to treat nocturia. The trouble is that nocturia does not generally improve reliably with TURP. The man might then find that his stream is better, but that his sexual function is now changed, and his nocturia remains bothersome; in other words, inadequate HCP insight and assessment may lead to treatment that could make the patient worse off.
Symptoms are not the same as signs; it would be nice if patients could report their LUTS in terms that map onto HCP observations, but this is clearly not the case. Thus, some care is needed to be precise in describing exactly what is meant. For example, “frequency” is a sign of how often someone passes urine in a given time period. This is not the same as “increased daytime frequency” (IDF) , which is a symptom of passing urine too often (in the patient’s opinion). Being imprecise when describing a patient’s problems risks difficulties with communication and decision-making.
We cannot presume mechanism from symptoms or signs. These are basically final common endpoints of disparate mechanisms; for example IDF may indicate overactive bladder, bladder inflammation, high fluid intake or medical conditions affecting fluid/salt handling. Likewise, slow stream can be due to outlet obstruction or bladder weakness. Thus, phrases like “obstructive flow” are dangerously misleading when applied to a symptom or a sign, as they clearly bias towards an assumption of bladder outlet obstruction even though it has not been proven.
Categories of LUTS and the overlap between some categories for some of the symptoms
2.2 Voiding and Post-Voiding Symptoms
The voiding symptoms are clearly associated with intentional passing of urine. Likewise post-voiding (or post-micturition) symptoms are linked to voiding, but are actually experienced after the conclusion of the urinary stream. They are a particularly common issue with ageing, principally among men, but by no means impossible in women.
2.2.1 Slow Stream and Hesitancy
“Slow stream ” is the archetypal voiding symptom and is “reported by the individual as his or her perception of reduced flow, usually compared to previous performance or in comparison to others”. Nonetheless, this is a symptom which can reach notable severity without necessarily causing substantial bother to the patient. Overall, slow stream is the symptom which appears to have the lowest burden on impairing QoL. Thus, the report of a slow stream may simply need acknowledgement rather than proceeding to interventional therapies.
The test most often used to evaluate this is a “free flow rate ”, meaning the measurement of volume over time (see Chap. 4). Here there is a characteristic reduction in the maximum flow rate (Qmax), and an overall pattern in which a prolonged time to reach the Qmax, even more prolonged to conclude (terminal dribble), and a fluctuating pattern of peaks may all be evident. A rather fundamental issue in assessing people reporting a slow stream or seen to have a slow Qmax is the voided volume at which this is occurring. If the bladder is in an appropriate volume range at the time of voiding, it gives the lower urinary tract optimum conditions for evaluating flow. If insufficiently full, there can be a slow flow simply because the bladder is not in suitable condition of readiness. This is relevant for flow testing, since anxiety at the time of attending hospital may cause people to ask to void rather early, so the FFR result must be considered bearing in mind voided volume and post-void residual. It can also be relevant in everyday life if people experience a constant desire to pass urine due to some form of pelvic irritation; when they go, it tends to be with the bladder under-full and consequently always slow. Thus, it is important to check whether the patient can ever manage a reasonable stream, and not base the clinical evaluation on typical voids if the volumes are generally small.
A large bladder diverticulum identified incidentally during cross-sectional imaging (CT) done for a different indication. The red arrow is indicating a small diverticulum next to a large diverticulum. These tend to have very little muscle in the wall, so they are likely to cause a PVR
Hesitancy is “the term used when an individual d escribes difficulty in initiating micturition resulting in a delay in the onset of voiding after the individual is ready to pass urine” [1]. Hesitancy can have a significant bother level associated, and consequently a higher impact on QoL [2]. The symptom is clearly appreciated by the patient describing an interval between being in the physical position of readiness to void and the actual moment at which flow is obvious. During a urodynamic test, following “permission to void”, it can be seen that the hesitancy comprises a delay before the start of evident pressure change (detrusor contraction), and a further delay before the flow meter picks up flow.
Bladder outlet obstruction (BOO) is the generic term for obstruction during voiding [1] and is characterized by increased detrusor pressure and reduced urine flow rate, indicating that the outlet calibre is reduced. It is usually diagnosed by studying the synchronous values of flow rate and detrusor pressure, and so it requires urodynamic studies to formalize the diagnosis [3]. In theory, any form of BOO (e.g. prostatic enlargement, bladder neck contracture, urethral stricture or urethral distortion in women) might lead to slow stream and hesitancy.
Detrusor underactivity (DUA) is a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span [1]. Like BOO, this is a urodynamic diagnosis and can only be assessed by studying the synchronous values of detrusor pressure and flow during the voiding phase. Mechanistically, this indicates that the expulsion pressure generated by the bladder is inadequate to overcome the normal outlet resistance. Of course some people might have both DUA and BOO. The potential aetiology of DUA includes idiopathic, neurogenic, myogenic and iatrogenic [4].
“Bashful bladder ”: in some situations, people can find it difficult to initiate a void and can experience considerable hesitancy. The stream is often slow-rising to Qmax when it finally starts, though the actual maximum flow eventually achieved may be reasonable. This type of situation is characteristically circumstantial, and sufferers clearly link it to situations where other people might be waiting to use the same toilet, or may be able to overhear them.
Simple tests such as uroflowmetry cannot differentiate between BOO and DUA, so healthcare professionals should consider the likely mechanism if they are deciding on whether to recommend interventional therapy. The voiding symptoms are clearly associated with intentional passing of urine, i.e. the flow during incontinence must not be equated with voiding; this is because people experiencing incontinence generally try to resist the leak by contracting their pelvic floor, so the leakage may occur slowly, but it is not necessarily due to a clinical diagnosis of BOO or DUA.
2.2.2 Straining and Intermittency
A person straining when passing urine. The red line plots abdominal pressure, and the marked up-and-down movement is a consequence of Valsalva manoeuvres (straining ). The blue line plots bladder pressure, and since the bladder is an abdominal organ, the same up-and-down activity is present. The black line is the flow, and it has spikes which coincide with each strain. Since straining is clearly effective for this person in generating the flow, it is rather unlikely they have any significant bladder outlet obstruction. The detrusor line (green) is almost flat, typical of an underactive detrusor. The maximum flow rate measured by the flow meter is not a real representation of lower urinary tract function since it is basically a spike (in this case the tallest spike reached 37 ml/s) caused by muscular effort generated by muscles outside the bladder.
The ability of abdominal straining to increase the flow rate depends on the outlet. If there is significant outlet obstruction, straining may not actually improve the stream, and the pointless effort means the patient tends not to bother. Consequently, straining is not a clear feature of benign prostate obstruction in men [6]. The physical effort in people who do strain can be detrimental on the structure of the pelvic floor, or the organs that cross it. Female patients who strain to void are at risk of causing pelvic prolapse, which potentially can exacerbate their urological problem. Emergence of haemorrhoids may also become problematic.
Intermittency is purely a voiding symptom since it is a description of the pattern of urine flow. However, straining may sometimes also be reported to happen post-voiding, and this may be observed during urodynamic testing. Presumably this signifies that the affected patient feels that there is a PVR or a pool of urine in the outlet, which they are attempting to remove.
2.2.3 Terminal and Post-Micturition Dribbling
Dribbling can occur in continuity with the void, making it a slow and protracted conclusion of passing urine known as “terminal dribbling ”.
Alternatively, there may be a clear-cut pause following conclusion of the stream and the escape of a few drops of urine. This is not an extension of voiding but is closely associated in terms of timing, so it is known as “post-micturition dribble ”.
Whilst the difference between these two may seem trivial, in fact the mechanism may well be substantially different. TD probably represents the conclusion of the detrusor contraction of voiding; with the bladder nearly empty, the contraction strength is lower (see discussion about “optimum volume range” above), which means that any outlet obstruction (specifically prostatic intrusion) is going to be more able to close down the lumen. Thus, TD is symptomatic of the unfavourable setup of bladder strength and outlet calibre which concludes voiding both in men with detrusor underactivity (weak bladder), or benign prostate obstruction (poor outlet calibre), or both. PMD must follow the conclusion of the detrusor contraction. Here the circumstance probably relates to the failure of dynamic expulsion to clear the urine fully from the outlet. Ordinarily, any urine passed beyond the sphincter has sufficient expulsion strength to carry it onwards past the meatus. However, when this is impaired, there is enough volume capacity in the outlet (especially in the male bulbar urethra) that urine can be held back temporarily—“bulbar pooling”. This is especially likely if the bulb is capacious, as may arise if the bulbospongiosus muscle is deficient. This situation leads to a dribble when the person leaves the toilet environment and external forces come into play, such as underwear or trousers pressing on the perineum, or leg movement or shifting alignments allowing gravity to bring the urine to the meatus. PMD thus closely follows TD but differs in the absence of concurrent detrusor contraction. For women, such a situation could arise if a urethral diverticulum below the sphincter temporarily traps urine. This is much rarer than bulbar pooling in men. The other explanation for women can be the potential for some of the urine stream to be misdirected (e.g. if there is any distortion of the urethra), causing some to enter the vagina, where it could get held back temporarily by the perineal body escaping when the woman changes posture on standing from the toilet.
Expressed in words, the ICS defines PMD as the term used when an individual describes the involuntary loss of urine immediately after he or she has finished passing urine, usually after leaving the toilet in men, or after rising from the toilet in women. Terminal dribble (TD) is the term used when an individual describes a prolonged final part of micturition, when the flow has slowed to a trickle/dribble [1]. PMD and TD are not the same, and clarity is needed when discussing the exact nature of dribbling with an affected patient [7].
PMD is a small, usually passive leakage of urine, following voiding. People quickly become aware when even a small amount (even just 1 ml) wets the underwear, while 2 ml may be enough to reach the outer surface of the trousers, where a small visible patch may become evident on close inspection. The importance of PMD is due to the high bother level associated with what appears to be a mild symptom. The condition can be a nuisance and cause embarrassment, and in Muslim societies it represents a serious problem for affected people as any leakage into the clothing denotes impurity and precludes prayer as well as use of the Mosque. The basic rule is that impurity must be washed away—mere drying is not enough.
The mechanism of PMD in men is due to temporary hold-up of urine in the urethra. Voiding allows urine to pass the sphincter, but if it is not fully expelled, some can be retained in the urethral bulb. Although the exact pathophysiological mechanisms of PMD are not yet known, PMD might occur secondary to a small volume of residual urine in either the bulbar or the prostatic urethra that is speculated should be “milked back” into the bladder at the end of micturition [8]. Sometimes detrusor function is also abnormal [9]. Different authors suggest that the problem results from failure of the bulbospongiosus muscle to evacuate the bulbar urethra. The nature of the problem explains why it becomes problematic. Furthermore, shaking and squeezing the penile urethra should get rid of any drops held there, but does not help the drops trapped in the bulbar urethra, since this area is fixed to the corpora cavernosum. Only manual pressure on the bulb to ease the urine forward to the penile urethra can achieve controlled expulsion. If that is not done, the drops will escape later, due to physical pressure (e.g. the trousers pressing on the perineum when moving about) or due to physical alignment allowing gravity to bring the drops out. Sometimes, PMD can result from urethral narrowing, e.g. a stricture or meatal stenosis. In these cases, the more distal and severe the stenosis, the more likely to manifest PMD. This circumstance may be associated with pain, since the detrusor contraction is actively resisted, in contrast to the usual PMD mechanism of bulbar flaccidity.
Few men admit having this problem, but a great many suffer from it and are often badly embarrassed by it. Men of all ages can be affected, but it is more likely in older men. Experiencing post-micturition leakage does not mean failure to urinate normally. Affected people may not notice any additional symptoms; however, they experience urine leakage when the penis is being replaced and clothes are rearranged after a visit to the toilet [10]. Women may have the same inconvenience, but it is less common than for men. This can be a problem for some women with learning and/or physical disabilities who are unable to sit upright on a toilet. It can occur in women with genital distortions (e.g. pelvic organ prolapse, labial intrusion or previous perineal repair) as the urine stream may be partly impeded, leading to diversion of some drops proximally into the vagina.
A survey was conducted to investigate post-micturition dribble in the general adult male population [11]. The incidence of post-micturition dribble in men in their 20s, 30s, 40s and 50s was 12, 13, 19 and 27%, respectively. The overall incidence was 17%. Of those who had experienced PMD, 14% dribbled almost daily. The degree of post-micturition dribble was limited to spotting or wetting of the underwear in 93%.
When PMD is reported in conjunction with other symptoms, a functional or anatomical abnormality of the lower urinary tract is common [12]. Furthermore, PMD is significantly correlated with erectile dysfunction (ED) [13] and reinforces the recognized relationship between LUTS and ED in middle-aged and older m en.
2.2.4 Sensation of Incomplete Emptying
The feeling of incomplete bladder emptying is a subjective sensation or complaint that the bladder does not fe el empty at the end of micturition, described as “a self-explanatory term for a feeling experienced by the individual after passing urine” [1]. To an extent it can be compared with the equivalent rectal sensation categorized with the term “tenesmus ” [14]. Effectively, people affected report that they feel their bladder still has urine in it despite having voided. In many cases they will have divined this correctly, i.e. the sensation is generally associated with a PVR. A study of more than 900 patients found a positive correlation between the sensation of incomplete bladder emptying and PVR volume [15]. This applied to women in all age groups, and men over the age of 60. In men, voiding symptoms and urgency were associated with a high PVR volume. In women, storage and voiding symptoms (except slow stream and terminal dribble) did not correlate with PVR volume.
Notwithstanding the association with a PVR, this is a symptom that can be present in people actually found to have full emptying, i.e. no PVR, and there can be a substantial impact on quality of life [16]. This situation is not adequately understood. Conceivably it could represent an erroneous supposition by the patient, or maybe it indicates sensitisation of peripheral sensory nerves. Consequently, it is appropriate to check for inflammation (e.g. by screening a voided urine specimen for inflammatory cells), or consider whether the sensation the person is experiencing might actually have a urethral origin.
The feeling of incomplete emptying might actually be reported simply because symptom scores ask about it, i.e. asking the question about the symptom might trigger a positive response in a person who is basically trying to convey severity of LUTS, rather than individually weighing up each symptom for personal relevance. This might explain why the severity of the feeling of incomplete bladder emptying corresponds with severity of both voiding and storage symptoms [16]. It may also indicate why people reporting it in the absence of PVR may experience resolution as a result of successful treatment of other LUT S [17].
2.2.5 Underactive Bladder
Certain combinations of LUTS can coexist in a predictable manner with sufficient prevalence to warran t descript ion as a symptom syndrome, and underactive bladder (UAB) is one such [4]. The most recent definition is from the ICS, which states that UAB is characterized by a slow urinary stream, hesitancy and straining to void, with or without a feeling of incomplete bladder emptying, sometimes with storage symptoms [18]. Impaired bladder emptying is a well-recognized cause of LUTS, but the symptoms produced do not always relate to voiding and may include increased frequency, urgency and incontinence [19]. Thus the UAB definition includes mention of storage LUTS, even though this is seemingly paradoxical. This syndrome is an attempt to place the symptoms into a situation that is practicable for use in primary care, in the expectation and hope that it will support future development of therapy [20, 21]. Access to urodynamic testing is not feasible for the initial assessment of patients, and by labelling patients in this way, it provides some basis for explaining the symptoms. Nonetheless, caution is needed to review the diagnosis and stay flexible on the interpretation of symptoms, since the allusion to mechanism of underactive bladder is entirely suppositional .
2.3 Storage LUTS
2.3.1 Urgency
“Tell me the moment when you perceive that your bladder is not empty anymore”. This is the first sensation of filling.
“Tell me when you have the sensation that normally tells you to go to the toilet, without any hurry, at the next convenient moment”. This is the first desire to void.
“The moment that you would definitely visit the nearest toilet to pass urine”. There should be no pain or any fear of losing urine. This is strong desire to void.
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