Desmopressin use in pediatric nocturnal enuresis patients: is there a sex difference in prescription patterns?

Desmopressin is a long-established treatment for nocturnal enuresis with clear guidelines regarding its usage. A sex difference in renal sensitivity has recently been reported in adults. The objective of this study was to investigate real-life desmopressin prescription in the Danish pediatric population, and prescription patterns which may reflect a sex difference in pediatric usage. Formulation, dose, treatment duration, and safety (hyponatremia) were investigated. 40,596 children received 214,220 desmopressin prescriptions between 2004 and 2011 in the Danish National Prescription Registry. Data were linked to hyponatremia diagnoses from the National Patient Registry. Although the lowest recommended dose of desmopressin oral lyophilisate is 120 μg, around a fifth of children were prescribed 60 μg for long-term use. A greater proportion of girls (22.6%) than boys (19.8%) received this low dose. Treatment duration was longer for boys than girls on oral lyophilisate (mean 489-524 vs. 414-462 days) and tablet (0.1 mg: 204 vs. 161 days). Prescribed daily dose was consistent with time between prescriptions, indicating no significant drug holidays. There were no admissions for hyponatremia during the observation period.

CONCLUSION

Danish national prescription data on pediatric desmopressin dosage are consistent with a greater sensitivity to desmopressin in girls than boys. Further studies are required. What is Known: • Desmopressin has been used for pediatric nocturnal enuresis for decades • Recent evidence suggests a sex difference in desmopressin sensitivity in adults What is New: • For the first time, desmopressin prescription practices in nocturnal enuresis are documented for an entire country • A higher proportion of girls than boys received a low dose of desmopressin, consistent with the sex difference in sensitivity reported in adults.

National Surveillance of Central Diabetes Insipidus (CDI) in Denmark: results from 5 years registration of 9309 prescriptions of desmopressin to 1285 CDI patients

CONTEXT

Epidemiological data for central diabetes insipidus (CDI) are sparse.

OBJECTIVE

The purpose of this study was to provide accurate epidemiological data on CDI on a national level.

DESIGN AND SETTING

This was a drug utilization and patient registry study during a 5-year period from 2007 to 2011.

METHODS

We used the Danish National Prescription Registry data linked with the Danish National Patient Registry to study the epidemiology of CDI using waiting time distribution and other pharmacoepidemiological methods.

PATIENTS

A total of 1285 patients with CDI were recorded in the observation period and given 9309 prescriptions for desmopressin in the nasal formulation, orodispersible tablet, or conventional tablet.

RESULTS

The period prevalence rate of CDI in Denmark over the 5-year period investigated was 23 CDI patients per 100 000 inhabitants, with a higher prevalence in children and older adults (>80 years of age). The 1-year period prevalence rate of CDI decreased in Denmark over the 5 years from approximately 10 to 7 CDI patients per 100 000 inhabitants. The yearly incidence rate of new cases of CDI was found to be 3 to 4 patients per 100 000. The incidence of (presumable) congenital CDI was found to be 2 infants per 100 000 infants. Half of the patients with CDI prescribed as oral treatment were provided dosing instructions to only administer the drug before bedtime, and one third of the CDI patients either had no specific instructions or were instructed to use the drug as needed. Hospital admissions due to severe hyponatremia occurred in 0.9% of patients over a 5-year period, predominantly in females with an incidence ratio of women to men of 1.8:1.

CONCLUSION

Half of the cases of CDI are acquired later in life. At least half of the patients with CDI are instructed to prevent nocturnal polyuria, but it is not clear whether their CDI remains uncontrolled during the daytime or, alternatively, whether they use desmopressin only as needed. Female patients with CDI had approximately twice the number of hospital admissions due to severe hyponatremia than male patients with CDI.

Renal concentrating capacity test using desmopressin at bedtime

A crossover trial was undertaken to evaluate the bedtime administration of desmopressin (Minirin) as a renal concentrating capacity test (RCCT). Medication was given intranasally as a single 20-microgram dose to 58 children ranging from 3 to 15 years of age with suspected or known renal impairment. The night-time test was shown to be a simple and effective means of assessing renal concentrating capacity. Comparison with the standard daytime test resulted in a 60 mosmol/kg higher mean osmolality in the night-time test. The results were reproducible, with a 95% confidence interval of -26 to 43 mosmol/kg. The procedure was easy to perform, with 51 of 52 patients (or their parents) preferring the night-time regimen compared with the daytime test. Night-time desmopressin therefore offers the potential of a user-friendly RCCT in patients with suspected impairment of renal tubular function.

Water intoxication in a patient with the Prader-Willi syndrome treated with desmopressin for nocturnal enuresis

PURPOSE

We report on a girl with the Prader-Willi syndrome who received desmopressin for nocturnal enuresis, and water intoxication developed after she ingested a large amount of fluid.

MATERIALS AND METHODS

The patient received 10 mg. desmopressin at bedtime for enuresis. She was hospitalized when a major motor seizure and coma (Glasgow coma scale 8) occurred after ingesting 48 ounces of fluid. Treatment included 3% saline, followed by 5% dextrose in water and sodium chloride given intravenously.

RESULTS

Serum sodium increased to 128 mEq./l. and serum glucose remained normal. Computerized tomography and magnetic resonance imaging of the head were normal and revealed no evidence of cerebral pontine myelinosis. Patient consciousness returned to normal by day 5 after the seizure.

CONCLUSIONS

In patients treated with desmopressin the risk of a seizure or altered level of consciousness can be minimized by not ingesting large quantities of fluid. We recommend that patients drink no more than 8 ounces of fluid on any evening that desmopressin is administered.

What is an acceptable treatment outcome?

Nocturnal enuresis is a multifactorial condition and, as such, is accessible to a variety of treatment modalities. In order to evaluate and compare the efficacies of different treatments in patients with specific pathophysiologies, studies should describe fully the patient population under investigation. In addition, many of the studies conducted to date have applied different outcome measures, making comparisons difficult. Therefore, it is necessary to define standard outcome measures that should be used universally. These may relate to the effect of the treatment on the number of wet nights per week, the effect on the family economy of a reduction in the number of episodes of enuresis and the effect on the child's self esteem and/or quality of life.

Hyponatremia in patients with nocturnal enuresis treated with DDAVP

Treatment of nocturnal enuresis with DDAVP is associated with a low incidence of adverse effects. The only reported serious adverse effect is seizure or altered level of consciousness due to water intoxication. We reviewed 14 articles that reported data on serum sodium in patients treated with DDAVP for nocturnal enuresis and 11 articles that reported patients who developed a seizure or altered level of consciousness during treatment with DDAVP for nocturnal enuresis. Excess fluid intake was identified as a contributing factor in 6 of the 11 case reports.

CONCLUSION

Hyponatremia is a potential adverse effect in patients with nocturnal enuresis who are treated with DDAVP. To prevent this adverse effect we recommend that the patients prescribed DDAVP for nocturnal enuresis should be counseled not to ingest more than 240 ml (8 ounces) of fluid on any night that DDAVP is administered.

Nocturnal polyuria and natriuresis in male patients with nocturia and lower urinary tract symptoms

PURPOSE

We investigated the circadian variation in urine output, plasma angiotensin II, aldosterone, atrial natriuretic peptide, arginine vasopressin and blood pressure.

MATERIALS AND METHODS

We studied 17 elderly men with nocturia and lower urinary tract symptoms, and 10 age matched controls without nocturia.

RESULTS

Of the 17 patients studied 11 had a lack of diurnal variation in urine output and increased nocturnal urine production associated with increased nocturnal sodium excretion, and 6 had a diurnal variation in urine output comparable to controls.

CONCLUSIONS

Nocturia in a large proportion of elderly men with lower urinary tract symptoms is caused by nocturnal polyuria and natriuresis.

The pituitary gland in nocturnal enuresis: MR findings

Nocturnal enuresis is considered a benign condition partially explained by a defect circadian rhythm of vasopressin. An organic cause may be responsible for an abnormal pituitary function, when enuresis persists into adulthood. In the present study the pituitary gland and surroundings of 8 adults suffering from primary monosymptomatic nocturnal enuresis were studied by magnetic resonance imaging. The pituitary gland appeared normal in all, except from a Rathke's cleft cyst observed in one patient. This cleft cyst was not considered to be clinically important. It was concluded, that severe nocturnal enuresis persisting into adulthood is not likely to be combined with detectable pathology on magnetic resonance imaging of the pituitary gland.

Enuresis nocturna can be provoked in normal healthy children by increasing the nocturnal urine output

In a large proportion of enuretics, the enuresis episodes are accompanied by high urine output at night. At this study we provoked a high urine output in normal non-enuretic children in order to investigate whether volume provocation per se could cause enuresis. In six of ten children it was possible to provoke nine enuresis-like episodes. The enuresis volumes were small with no relation to functional bladder capacity. It is concluded, that increased urine output at night may produce enuresis-like episodes even in normal children.

A pharmacodynamic study of desmopressin in patients with nocturnal enuresis

The pharmacokinetics of desmopressin (1-desamino-8-D-arginine vasopressin) were investigated in 8 patients with nocturnal enuresis, of whom 4 were known to respond completely to desmopressin and 4 were nonresponders. A decrease in urine production was confirmed in responders after the administration of desmopressin while the drug did not cause antidiuresis in nonresponders. Absorption and excretion of desmopressin were identical in each group. Results indicate at least 2 pathophysiological mechanisms in nocturnal enuresis, including insufficient nocturnal production of arginine vasopressin and impaired renal sensitivity to arginine vasopressin and desmopressin. Each type results in high nocturnal urine production.

Biofeedback treatment of children and adults with idiopathic detrusor instability

In adults and children suffering from urge, urge incontinence, frequent voidings, and nocturia, urodynamic examination often confirms the diagnosis of detrusor instability. We assessed the outcome of biofeedback therapy in 15 children aged 6-12 years and 7 adults aged 20-52 years, all with cystometrically proven detrusor instability. The detrusor pressure was visually conveyed to the patient during repeated bladder fillings. The patient was instructed to interrupt detrusor pressure increments by tensing the pelvic floor musculature. None of the children were found completely cured; however, 9 showed a marked decrease in either the number of the extent of symptoms. Two children showed moderate improvement, while 4 remained unaffected by the treatment. One adult was completely cured, 2 improved moderately, and 4 showed no improvement. None of these patients were converted to stable cystometry. Upon termination of the BF treatment a follow-up study was conducted for patients exhibiting pronounced or moderate improvement. The beneficial effect was maintained except in one case.

29-week doxazosin treatment in patients with symptomatic benign prostatic hyperplasia. A double-blind placebo-controlled study

In a placebo-controlled study, the safety and efficacy of the selective alpha 1-adrenoceptor-blocking agent doxazosin 4 mg once daily in the symptomatic treatment of benign prostatic hyperplasia (BPH) were evaluated. One hundred patients were primarily included in a 9-weeks study, and after this 75 patients accepted to continue in the present 20 weeks extension. Of the patients in the doxazosin-group (DG) 61% reported overall improvement against 53% in the placebo-group (PG)--(p = 0.56). In the DG, 49% of obstructive symptoms were improved compared to 27% in the PG (p < 0.01), and a reduction of 60% of irritative symptoms was found in the DG against 36% in the PG (p < 0.01). Daytime frequency was reduced by median 1.5 in the DG and remained unchanged in the PG (p < 0.01). Nocturia was reduced by median 1 and 0.5 respectively (p = 0.06). Maximum urinary flow rate (MFR) was improved by median 1.5 ml/s in the DG, while it deteriorated by median 0.5 ml/s in the PG (p < 0.05), Considering postvoid residual urine volume, cystometry variables (first sensation and bladder capacity), changes in sexual function and adverse events there was no difference between the two groups. In conclusion, doxazosin 4 mg once daily in long-term treatment of patients with BPH reduces both obstructive and irritative symptoms, daytime voiding frequency and although only slightly, significantly augments MFR without interference with sexual function and without other serious adverse effects.

Survival after transurethral resection of the prostate: a 10-year followup

Among 141 men who underwent transurethral resection of the prostate from late 1979 to early 1980 followup for 10 years was done, registering total mortality rate and individual dates of death. The mortality of the group was compared to an age-matched group from the background population of men for each of the 10 years. During the observation period the mortality of the group as a whole as well as that of the patients 65 years old or older at operation were equal to that of the background population at all times. Withholding recommendation of transurethral resection of the prostate in favor of other types of prostatic surgery on the grounds of a higher long-term mortality rate is not supported by our material.

A dose titration, and an open 6-week efficacy and safety study of desmopressin tablets in the management of nocturnal enuresis

The efficacy and safety of 6 weeks of treatment with desmopressin tablets at doses of 200 to 400 micrograms.at bedtime were investigated in 33 children with monosymptomatic nocturnal enuresis. During an initial 1 to 2-week dose titration period 22 patients (67%) became either completely dry or showed improvement, 7 (21%) showed no response and 4 (12%) dropped out of therapy. During tablet treatment 17 patients on 400 micrograms.and 5 on 200 micrograms.at bedtime increased the number of weekly dry nights from 2.0 +/- 1.6 (standard deviation) during a 2-week observation period to 5.2 +/- 1.9 (p < 0.001). During a subsequent 2-week period 40 micrograms.intranasal desmopressin showed a similar overall efficacy, with a mean of 5.4 +/- 1.6 dry nights per week. In addition, intranasal treatment was able to increase the number of dry nights in 2 of the 7 nonresponders to tablet treatment.

[Enuresis in childhood: what should one know? What should one do?]

Bladder control is a developmental process which is determined by somatic, individual psychological and psychosocial factors. It depends on the maturation of bladder capacity and of adequate neuromuscular coordination, on the quantity of urine and on appropriate recognition of bladder expansion. The latter especially is clearly correlated to healthy individuation and psychosocial integration of the child. Statistically, 80-90% of children have successfully developed bladder control at the age of 4-6 years. In the remaining 10 or 20% who do not attain dryness during daytime or at night, wetting is often felt to be disturbing state, sometimes more by the parents than by the children. The state is called enuresis. The physician is expected to master the problem of night or daytime enuresis diagnostically as well as therapeutically. Although in most cases enuresis represents a retardation of normal development, it is important not to miss the rare, but, if present, important disturbing factors. Disorders can occur at all above mentioned levels, either in isolation or combined. Although proposing the simplest diagnostic measures, the present paper represents an optimal workup during which none of the rare somatic or complicated psychological disturbances, which would need specialized attention, should be missed. After this workup the therapeutic pathways are clear. On the one hand, relevant somatic and/or psychological disorders must be treated specifically (often in collaboration with the specialist). On the other side, there is the large number of enuretics who are, by all criteria, normal children. In these it is possible to accelerate the developmental process by performing an elaborate micturition protocol which has a good chance of success, provided, however, there is optimal cooperation between physician, parents and child.

The pathophysiology of enuresis in children and young adults

Bedwetting is the most common urologic complaint among children. Wetting frequency at age 7 years varies from 5% to 15%. Treatment has been multimodal: drugs to depress bladder activity, increase urethral resistance, or modulate sleep; electrophysiologic treatment; and, recently, urine production modulation. All of these approaches reflect a lack of sufficient knowledge of the underlying pathophysiology of nocturnal enuresis. Over the last 13 years, enuresis studies at the Institute of Experimental Clinical Research, the University of Aarhus, Denmark, have focused on sleep disturbances, bladder reservoir function, urine output, and a combination of the three. Sleep studies indicate that: enuretic patients are normal sleepers; the voiding characteristics of an enuretic episode are similar to those of voluntary voiding during the day; and enuresis can take place during any stage of sleep, but generally occurs when the bladder is filled to the equivalent of maximal daytime functional capacity. Bladder reservoir capacity appears to be normal and bladder instability an unimportant factor in the pathology of nocturnal enuresis. However, enuretic patients have been shown to lack the normal nocturnal increase in antidiuretic hormone levels and had nocturnal urine production up to four times the volume of functional bladder capacity, which explains the need for bladder emptying. These findings open new avenues to the approach to treatment based on antidiuretic therapy.

Urodynamic biofeedback training for children with bladder-sphincter dyscoordination during voiding

Neurologically normal children with recurrent urinary tract infections (UTIs), night- and daytime wetting, and urge and painful voiding may have staccato voiding due to pelvic floor contractions. The immediate effect of non-invasive urodynamic biofeedback (BF) therapy was assessed using a historical follow-up study in 31 children aged 5-15 years suffering from urodynamically proven overactive urethra during voiding. A long-term follow-up study was performed to investigate whether improvement was maintained. Twenty-four children (77.5%) benefited from the treatment. Of these 16 (51.5%) were cured, while 8 (26%) had a pronounced reduction in their symptoms. Although the flow was normalized in 17 (55%) and nearly normalized in 7 (22.5%), there was no significant correlation between subjective and objective criteria of improvement. Similarly, no relationship was found between the initial urodynamic characteristics and the treatment outcome. During a mean follow-up time of 4 years (range: 1-7.5 years) two of the initially cured patients relapsed. They were recurred with a refresher course. Three had had a single or a few episodes of cystitis in the course of several years. Of the patients with pronounced reduction in their symptoms, three relapsed. A refresher course was attempted in two patients; one was successful. It can thus be concluded that BF is an effective way of treating this disturbance and the beneficial effect is to a wide degree maintained.

Doxazosin treatment in patients with prostatic obstruction. A double-blind placebo-controlled study

The safety and efficacy of the selective alpha 1-blocking agent doxazosin 4 mg once daily in the symptomatic treatment of benign prostatic hyperplasia were evaluated in a randomized, double-blind and placebo-controlled 9-week study of 100 patients. By patients' overall assessment of voiding difficulties, 79% in the doxazosin group (DG) and 44% in the placebo group (PG) reported improvement (p = 0.001). In the DG, improvement was noted in 63% of obstructive symptoms compared to 32% in the PG (p = 0.015), whereas improvement was noted in 76% and 45%, respectively, of irritative symptoms (p = 0.12). Daytime frequency was reduced by 1.5 in the DG and increased by 0.3 in the PG (p = 0.001), and nocturia was reduced by 1.1 and 1.0, respectively (p = 0.12). Maximum urinary flow rate was improved by 1.5 ml/s in the DG, while it deteriorated by 0.3 ml/s in the PG (p = 0.11). Considering postvoid residual urine volume, cystometry variables (first sensation and bladder capacity) and adverse events there was no difference between the two groups. In conclusion, doxazosin 4 mg once daily is safe and effective in relieving symptoms in patients with BPH.

Long-term treatment of nocturnal enuresis with desmopressin. A follow-up study

Eight patients with monosymptomatic nocturnal enuresis (age 11-24 years) were investigated prior to and after 24 weeks of desmopressin treatment in order to evaluate the impact on the endogenous vasopressin secretion and urinary output. No effect on plasma vasopressin, diurnal urinary volume, and urinary osmolality were found after this long-term treatment. Overall no changes in either body weight, blood pressure, or hematological variables were demonstrated. This supports previous findings that the treatment appears to be well tolerated and free of side effects in longer term.

Diurnal variation of plasma atrial natriuretic peptide in normals and patients with enuresis nocturna

The circadian variation of plasma atrial natriuretic peptide (ANP) in relation to urinary excretion of sodium (UNa) and potassium (UK) as well as clearance of creatinine (Ccrea) was assessed in 15 juvenile patients with enuresis nocturna and compared with 11 age-, sex-, and weight-matched normal subjects. Normal juveniles showed a highly significant diurnal variation (p less than 0.001) of plasma ANP with diurnal peak levels at midnight (0000 hours) and minimum levels at 0400 hours. Enuretic patients showed a similar diurnal rhythmicity with normal levels during day and night. In normals both UNa and UK showed significant diurnal rhythmicity with a marked reduction from daytime to night-time. Although the total diurnal excretions of UNa and UK were similar to normals, patients with enuresis showed abnormal diurnal variation in both UNa (p less than 0.05) and UK (p less than 0.01). The abnormal circadian rhythm of UNa and UK in enuretics seemed to be caused by abnormal tubular handling as similar abnormalities were found in the fractional excretions and as the circadian variation of Ccrea was normal. Especially during the first hours of sleep (2200 hours to 0000 hours), the patients showed polyuria (230 +/- 138 ml vs 116 +/- 58 ml, p less than 0.01), natriuresis (20.9 +/- 16.3 mmol l-1 vs 10.7 +/- 6.8 mmol l-1, p less than 0.01), and kaliuresis (7.3 +/- 6.3 mmol l-1 vs 3.7 +/- 2.3 mmol l-1, p less than 0.05), despite normal levels of plasma ANP. In conclusion, the study describes the diurnal variation of plasma ANP in relation to urinary excretion of sodium and potassium in a juvenile normal population. Patients with nocturnal enuresis show abnormal diurnal rhythmicity in the urinary excretion of sodium and potassium that is not correlated to the plasma levels of ANP.

Sleep cystometries in children with nocturnal enuresis

A combined analysis was done of sleep and bladder filling during sleep. Cystometry did not specifically affect sleep, since most of the cystometry studies in cases of enuresis did not lead to sleep stage changes on electroencephalography. Bladder instability was not accompanied by lighter sleep. Increasing patient age did not appear to have any influence on sleep or bladder behavior. We conclude that it is possible to provoke enuresis at any sleep stage and that sleep is unaffected by bladder filling in enuretic patients.

Abnormal diurnal rhythm of plasma vasopressin and urinary output in patients with enuresis

The diurnal variation of plasma vasopressin (AVP), urinary excretion rate, urinary osmolality, and serum osmolality was studied twice in 15 patients with enuresis and in 11 age, weight, and sex matched nonenuretic normal subjects. A diurnal rhythm of AVP with constant levels during the day (8 AM-10 PM) and a highly significant increase during the night (10 PM-8 AM) was found in normal subjects. In contrast, enuretics showed a significantly less pronounced nocturnal increase in AVP with significantly lower nocturnal levels than normal subjects. Normal subjects showed a diurnal rhythm in urinary excretion rate reciprocal to urinary osmolality with a low and highly concentrated nocturnal urinary output. In enuretics, however, this normal diurnal rhythm was absent. In conclusion, an abnormal diurnal rhythm of AVP seems to be an important pathophysiological factor in enuresis, explaining the abnormally high nocturnal urinary volume and the low nocturnal urinary osmolality found in these patients.

Terodiline in the treatment of diurnal enuresis in children

Efficacy and tolerance of the anticholinergic and calcium antagonistic drug terodiline (Mictrol) were investigated in comparison to placebo in 42 children with diurnal enuresis. The study was double-blind with a modified cross-over design with 2 treatment periods of 4 weeks. Terodiline in a daily dose of 25 mg was well tolerated. A statistically significant decrease in the number of wet episodes per day was found with terodiline when compared to placebo. In addition a high patient preference for terodiline was observed. This study shows that terodiline is effective in the treatment of daytime enuresis in children. The low incidence of side-effects also favours the use of terodiline in children.

The hydrodynamic consequences of transuretero-ureterostomia

A transuretero-ureterostomy was performed in 8 pigs. In 4 pigs a non-dilated urinary tract was seen and pressure and electromyographic recordings showed that the procedure did not affect the electromyographic impulses in the recipient ureter. Impulses from the donor ureter were not transmitted to the common distal ureter. Two pigs died postoperatively from urinary leakage and two pigs developed stasis.

Diuresis renography and simultaneous renal pelvic pressure in hydronephrosis

We investigated 23 hydronephrotic kidneys in 10 male and 12 female patients (mean age 32 years) with diuresis renography and simultaneous, continuous renal pelvic pressure measurement to compare isotope washout with pelvic pressure changes. No correlation was found between these 2 parameters. Of the kidneys 14 were investigated further by a standard Whitaker pressure flow study. There was only a poor correlation between diuresis renography and the pressure flow study, and between the pelvic pressures during perfusion and forced diuresis. Impaired renal uptake fraction signifying the degree of obstructive nephropathy did not correlate with the dynamic tests. An Anderson-Hynes pyeloplasty was done in 19 patients. There was no correlation between the presence of organic stenosis or external compression and the outcome of the diagnostic tests. We concluded that the currently used diagnostic procedures for hydronephrosis generally are insufficient to discriminate between significant and nonsignificant obstruction.

Urethral pressure variations in healthy females during rest and sleep

Recent studies have shown the occurrence of rhythmic urethral pressure variations (UPV) in the normal female urethra in the awake state. The nature of these variations still needs further elucidation. In this study we investigated the changes in urethral pressure (UP) and in UPV as they occur in healthy females awake and asleep. UPV, intravesical-(IVP) and rectal pressure (RP), together with anal electromyography (EMG) and electroencephalography (EEG) were measured in 10 healthy fertile female volunteers. The registration was done in the awake state, during falling asleep and during sleep. During falling asleep the average urethral pressure as well as the UPV amplitude and frequencies decreased and remained at a lower stable level during sleep. Urethral pressure and its variations seemed to be interrelated since the UPV frequency and amplitude decreased when the average UP decreased. From this study it appears that urethral pressure is influenced by extrinsic factors such as the waking, resting and sleeping states. Although some extrinsic modulation of urethral pressure variations occurs, their persistance in sleep suggests their local nature.

Significance of the extent of transurethral prostatic resection for postoperative complications

The significance of the extent of transurethral prostatic resection for benign prostatic hypertrophy was evaluated as regards early and late postoperative complications in a prospective, randomized study. The two treatment groups were preoperatively comparable in age, incidence of urinary retention and estimated prostatic weight. In 83 cases the median weight of resected tissue was 18 (range 4-118) g, while in 84 cases the resection was less extensive--median weight 7 (1-40) g. No significant intergroup difference was found in incidence of bladder tamponade, bladder perforation, urinary tract infection or pneumonia. The blood transfusion need was greatest among the patients with complete transurethral adenomectomy of the prostate. Concerning late postoperative complications, the groups did not differ in incidence of urethral stricture, bladder neck contracture or reoperation for benign prostatic hypertrophy. Patients with preoperative urethral instrumentation had heightened risk of developing postoperative urethral stricture.

Experimental electrical stimulation of the bladder using a new device

Repeated bladder contractions were evoked during a six month period in three unanaesthetized female minipigs by using unipolar carbon fiber electrodes embedded in the bladder wall adjacent to the ureterovesical junction. In contrast to bipolar and direct bladder muscle stimulation unipolar electrodes at each ureterovesical junction evoked bladder pressure increase similar to those produced in previous investigations in dogs. Sacral nerve stimulation of S2 evoked bladder contraction at a minimal current. Microscopic examination revealed no cellular reactions to the carbon fibers but a subcutaneous reaction to the receivers was seen and was thought to be due to mechanical irritation. The clinical implication of the findings is discussed.

Enuresis as protective factor in vesicoureteral reflux

In 83 patients with non-neurologic, nonoperated vesicoureteral reflux the relation between enuresis and nephropathy was analyzed. The material showed that in spite of identical age, sex distribution, previous history of recurrent urinary tract infections, and the number of refluxing units, patients with enuresis showed a significantly lower degree of reflux nephropathy. This significant difference was even more pronounced when the age of the patients was considered. Thus patients below the age of ten showed reflux nephropathy in 25 per cent of the refluxing units in enuretic patients compared with 30.8 per cent in the nonenuretic patients. Above the age of ten 76.2 per cent of the refluxing units showed renal scarring in the nonenuretics compared with 27.8 per cent in the enuretics. The study stresses the importance of lower urinary tract malfunction in the pathogenesis of reflux. Enuresis might act as a safety valve mechanism reducing the possibility of reflux nephropathy.

Diurnal anti-diuretic-hormone levels in enuretics

The diurnal antidiuretic hormone levels were studied in eleven enuretics and related to urine production and functional bladder capacity. A fluid deprivation test monitoring antidiuretic hormone levels was undertaken in four patients. The study suggests that the normal increase in nighttime antidiuretic hormone levels is absent in enuretics, who show a stable hormone level both day and night. Consequently the volume of night urine production approximates day urine production per hour. The functional bladder capacity was clearly exceeded at night in eight of eleven patients. The fluid deprivation test showed a normal response to fluid deprivation. In conclusion, the study adds further evidence that bladder capacity is a major factor in enuresis. Urine volumes that exceed bladder capacity at night may be caused by a lack of diurnal rhythmicity in antidiuretic hormone levels.

A device for treatment of destrusor hyperreflexia by bio-feedback

Treatment of detrusor hyperreflexia is still a difficult field. Recently bio-feedback has been described as a successful treatment of voiding dysfunction. In this paper we describe a device, which makes it possible for the patients to register any pressure changes in the bladder.

Simultaneous registration of sleep-stages and bladder activity in enuresis

A combined monitoring of sleep stages and bladder activity for the evaluation of enuresis is on trial. Polygraphic recordings in 7 patients, comprising the preliminary material, have shown single-event bladder contractions without forewarning or changes in sleep stages. A volume dependency of the enuresis episodes seems so far to be a major mechanism.