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The effect of endodontic access cavity preparation and subsequent restorative procedures on incisor crown retention.

Endodontic treatment often will require access through existing crowns. This study was undertaken to determine whether endodontic access cavity preparation affected the retention of crowns in anterior teeth and then to determine whether this retention can be regained by amalgam or post-retained amalgam restorations. Twenty extracted human incisors were mounted in acrylic blocks and prepared for crowns. Metal copings were fabricated and cemented with zinc phosphate cement and the forces required to displace the copings after various procedures were measured with a tensile testing machine. Retention values for all stages were compared with the initial retentive value for each coping without an access cavity which was set at 100 per cent. Group one specimens had the following means: copings with access cavity, 85.64 +/- 28.65 per cent of the initial values; amalgam flush with lingual dentine, 95.81 +/- 36.2 per cent; amalgam flush with coping, 114.89 +/- 34.5 per cent. Group two means were: copings with access cavity, 89.95 +/- 21.42 per cent; posts and amalgam, 177.37 +/- 77.5 per cent. Statistical analysis with the two sample t test showed that retention with post-retained amalgam restorations showed significantly higher values when compared with access cavities without restorations (p < 0.05). Retention values for post-retained restorations were significantly different from those just using amalgam. This study demonstrated that endodontic access cavities reduced the retention of the crowns, and subsequent restoration with amalgam or a post can regain the retention.(ABSTRACT TRUNCATED AT 250 WORDS)

Crowns↗

Evidence that high dose cortisol-induced Na+ retention in man is not mediated by the mineralocorticoid receptor.

We have previously shown that high dose cortisol (F; 240 mg/day)-induced Na+ retention and systolic blood pressure (BP) increases are not inhibited by the glucocorticoid (type II) receptor antagonist RU486. Adequacy of type II receptor blockade with RU486 was clearly demonstrated, indicating that the Na+ retention was not mediated through the glucocorticoid receptor. Spironolactone (Sp: 400 mg/day), in a preliminary assessment, also did not inhibit F-induced Na+ retention. The purpose of this study was to determine whether the Na+ retention produced by F administration is mediated by the type I receptor by comparing the effects of F to a potent type I agonist [9 alpha-fludrohydrocortisone (9 alpha FF)] with and without Sp administration. The effects of the two agonists and Sp on urinary K excretion and BP were also compared. Normal male volunteers, on a constant daily diet for 10 days, received either F (240 mg/day) or 9 alpha FF (3.0 mg/day) with or without Sp (400 mg/day) for the last 5 days. The mean cumulative reductions in Na+ excretion during the 5 days compared to baseline values before hormone administration were 255 +/- 38 and 494 +/- 81 mmol/5 days for F (n = 9) and 9 alpha FF (n = 5), respectively (P = 0.01). Sp (n = 5) completely inhibited 9 alpha FF-induced Na+ retention (494 +/- 81 vs. -37 +/- 130 mmol/5 days; P less than 0.01), but had no effect (n = 5) on F-induced Na+ retention (255 +/- 38 vs. 193 +/- 50 mmol/5 days; P = NS). After the expected first day kaliuresis, the effects of both steroids on net cumulative urinary K+ excretion were minimal. Systolic BP was increased by F, but not 9 alpha FF, and Sp did not inhibit this increase. A 2-fold greater Sp-inhibitable Na(+)-retaining effect of the mineralocorticoid demonstrates that the failure of Sp to block F-induced Na+ retention is not due to inadequate type I receptor blockade. Based on these findings and earlier studies, we conclude that high dose (stress level) F-induced Na+ retention and systolic BP increase are not mediated by either the mineralo- or glucocorticoid receptor in normal man.

Adult↗

Retentive forces of two magnetic systems compared with two precision attachments.

Magnetic retention devices based on cobalt/samarium alloy are new to dentistry, whereas precision attachments have been used for many years. In this study, the retentive forces of two magnetic systems were compared with two different precision attachment units. The retentive forces were evaluated with an Instron testing machine with a cross-head speed of 0.5 mm/min. Eight samples were used for each of the four attachments for a total of 32 samples. The attachments were embedded in an acrylic block and tested for initial retention and retention after 300 cycles. The retentive forces of the precision attachments were greater than the magnetic attachments for the initial retention. However, as more cycles were completed, the retentive force decreased in the precision attachments and increased in the magnetic attachments. The results were statistically significant among the four attachment systems (p = 0.0117).

Acrylic Resins↗

Counting strategies and assimilation effects in short-term retention of temporal information.

The purpose of the present research was to examine proactive interference in general and assimilation effects (i.e., shifts in constant error caused by prior responses) in particular, when subjects used covert counting to aid their retention of the temporal information. Visually presented durations of 1, 4, and 8 sec. were estimated by 18 subjects under the method of reproduction. Three retention intervals (i.e., immediate, 15, and 30 sec.) and three intertrial intervals (i.e., immediate, 15, and 30 sec.) were employed. Analysis of constant error provided no indication that proactive interference was operating in the retention of temporal information as there was no increase in error across trials, no increase in error for longer retention intervals, and no interaction between trials and retention intervals. Also, there was no change in variable error as the retention intervals lengthened for any temporal duration except for the 4-sec. criterion. Finally, the rate of counting (counting units/sec.) was different across the durations to be remembered. The major conclusion of the present research was that counting greatly facilitates retention of temporal information as compared to retention without such a time-aiding strategy.

Attention↗

The moderator effect of test anxiety in the relationship between test expectancy and the retention of prose.

The effect of test expectancy and test anxiety on the retention of prose is not yet profoundly examined in an ecologically valid learning context. The influence of test expectancy, test anxiety, and differences in intelligence on the retention of prose was addressed in the hypothesis that test anxiety would act as a moderator between test expectancy and memory retention of prose. Also examined was whether this relation would still be valid if differences in general intelligence were controlled. University freshmen (N=292) participated. Analysis indicated that test anxiety acted as a moderator between test expectancy and prose memory performance, even after controlling for differences in general intelligence. The low and high test-anxious group expecting a retention test seemed to profit from positive arousal elicited by the expectedness of a retention test. The high test-anxious group not expecting a retention test performed in a rather detrimental way on a retention test given negative arousal elicited by the unexpectedness of a retention test. Implications for further research are elaborated and discussed.

Adolescent↗

Proteinuria and renal function during and after acute urinary retention.

PURPOSE: Benign prostatic hyperplasia is the most common neoplasm as well as the main cause of bladder outlet obstruction in men. It may progress to involve a risk of urinary retention. We investigated the effects of acute urinary retention on renal function. MATERIALS AND METHODS: We evaluated renal function using biochemical markers in 25 men with a mean age of 69 years in whom an episode of acute urinary retention a mean of 31 hours in duration was due to bladder outlet obstruction. Patients were followed for 6 months after acute retention was relieved. Patients were not known to have had any renal disease previously. RESULTS: During acute urinary retention at presentation, and after 1 and 6 months we noted albuminuria in 100, 92 and 54% of patients, elevated alpha 1-microglobulin excretion in 54, 39 and 58%, and elevated beta 2-microglobulin excretion in 17, 19 and 9%. Serum creatinine or creatinine clearance did not predict proteinuria. All parameters became normal at 6 months in only 2 cases. CONCLUSIONS: Acute urinary retention affects glomerular and tubular renal function. After acute urinary retention was relieved increased glomerular permeability and tubular damage persisted in the majority of patients. This condition may have been partially due to previous long-term bladder outlet obstruction. Our findings stress the importance of the rapid recognition and treatment of acute urinary retention.

Acute Disease↗

Incidence rates and risk factors for acute urinary retention: the health professionals followup study.

PURPOSE: We define incidence rates and risk factors for acute urinary retention. MATERIALS AND METHODS: In 1992, 41,276 United States male health professionals 45 to 83 years old self-reported baseline health data and American Urological Association symptom index scores. In 1995 a subset reported the year of any episode of acute urinary retention requiring catheterization. Of 8,418 respondents 6,100 without a history of prostate cancer, prostatectomy or acute urinary retention before 1992 provided data. Incidence rates from 1992 to 1995 were calculated and risk factors were assessed using logistic regression. RESULTS: During 15,851 person-years of followup 82 men reported an episode of acute urinary retention (sampling weighted incidence 4.5/1,000 person-years, 95% confidence intervals 3.1 to 6.2). Rates increased with age and baseline symptom severity. In men with symptom score 0 to 7 (none or mild lower urinary tract symptoms) the incidence of acute urinary retention increased from 0.4/1,000 person-years for those 45 to 49 years old to 7.9/1,000 person-years for those 70 to 83 years old. In men with symptom score 8 to 35 (moderate or severe lower urinary tract symptoms) rates increased from 3.3/1,000 person-years for those 45 to 49 years old to 11.3/1,000 person-years for those 70 to 83 years old. Men with a clinical diagnosis of benign prostatic hyperplasia and a symptom score 8 or greater had the highest rates (age adjusted incidence 13.7/1,000 person-years). All 7 lower urinary tract symptoms comprising the American Urological Association symptom index individually predicted acute urinary retention (age adjusted odds ratio 1.8 to 2.9 for symptoms occurring more than 25% of the time during the last month). The sensation of incomplete bladder emptying, having to void again after less than 2 hours and a weak urinary stream were the best independent symptom predictors. Use of medications with adrenergic or anticholinergic side effects also predicted acute urinary retention. CONCLUSIONS: Acute urinary retention occurred relatively infrequently but older age, moderate or severe lower urinary tract symptoms, a diagnosis of benign prostatic hyperplasia and specific drug therapies significantly increased the risk of occurrence.

Acute Disease↗

The cause and natural history of isolated urinary retention in young women.

PURPOSE: Using a questionnaire mailed to patients we evaluated the course and natural history of urinary retention in women, of which the cause is attributed to electromyography abnormality of the striated urethral sphincter. Previously urinary retention in young women has often been considered to be due to multiple sclerosis or a manifestation of a psychogenic disorder. MATERIALS AND METHODS: A questionnaire was mailed to 216 women with abnormal sphincter electromyography and urinary retention. Of the 112 responses we analyzed the 91 from those who had been in complete urinary retention. RESULTS: Mean patient age at the onset of complete retention was 27.7 years (range 10 to 50). No patients had neurological features indicating a cauda equina lesion or central demyelination and none had progressed to features of a general neurological disorder. Mean maximum bladder capacity at the initial episode of complete retention was 1,208 ml. Of the women 65% reported an event that had apparently precipitated urinary retention, most commonly a gynecologic surgical procedure using general anesthesia. Sacral neuromodulation was the only therapeutic intervention that restored voiding. CONCLUSIONS: The concept of an organic cause of urinary retention in otherwise healthy young women has considerable importance in terms of correct management. Neurological investigation in these women does not reveal underlying neurological disease. It is thought that this disorder is due to a primary failure of relaxation of the striated urethral sphincter.

Adolescent↗

[Study on retention and stability of linear occlusal complete dentures].

OBJECTIVE: To learn retention and stability of linear occlusal complete dentures by investigating the subjective feelings of patient and the value of retention force. METHODS: Static retention forces of maxillary and mandibular dentures were measured for 25 patients wearing linear occlusal dentures by using Hz-1 retention dynamometer. The subjective feelings of patients in functional state were gained simultaneously through questionnaire. RESULTS: Linear occlusal dentures demonstrate good retention in static and dynamic state. Among patients with severe resorption of residual ridge (RRR), mandibular linear occlusal dentures (shown good retentive subjective feelings) demonstrate significantly smaller retention force than those with slight or medium degree of RRR. There is no correlation between the subjective feelings and the values of retention forces of mandibular dentures. The subjective feelings of patients wearing new linear occlusal dentures are much better than that of old anatomic occlusal dentures. CONCLUSION: Linear occlusal dentures improve the performances of dentures by enhancing their stability during mastication movement.

Aged↗

Retention forces and seating discrepancies of implant-retained castings after cementation.

PURPOSE: The purpose of this in vitro study was to evaluate the influence of cement type and application technique on seating discrepancies and retention forces of noble alloy castings cemented on titanium abutments. MATERIALS AND METHODS: Eugenol-free zinc oxide (Freegenol), zinc phosphate (Harvard), glass ionomer (KetacCem), polycarboxylate (Durelon), and self-adhesive resin (RelyX Unicem) cements were used. The inner surfaces of the castings were either completely coated or half-coated with cement. Abutments were used as delivered with a machined surface for the first part of the study. Groups of 8 castings were cemented in both ways. For the second part of the study, the abutments were air-abraded (aluminum oxide, 50 microm particle size), and groups of 8 completely coated castings were cemented with all cements. Marginal discrepancies were measured before and immediately after cementation. Tensile tests were conducted to measure the retention forces. Statistical analysis was performed with pair-wise comparison using the Wilcoxon rank sum test modified by Bonferroni-Holm. RESULTS: Change in seating discrepancies did not differ significantly among the different application techniques. The median retention forces for completely-coated castings were 177 N for eugenol-free zinc oxide, 346 N for zinc phosphate, 469 N for glass ionomer, 813 N for polycarboxylate, and 653 N for self-adhesive resin. With respect to retention force, 3 significantly different groups (P < .05) were identified: (1) zinc oxide, (2) zinc phosphate/glass ionomer, and (3) polycarboxylate/self-adhesive resin. No differences in retention between the 2 coating techniques were found for any cement. However, air abrading the abutments resulted in increased retention of the castings for some of the cements. CONCLUSIONS: Half-coating of the restorations with cements did not result in reduced retention values compared to the complete coating technique, but air abrasion resulted in increased retention with some cements.

Air Abrasion, Dental↗

[Retention in the conic telescope crown system. The influence of the inner crown form].

In a study of retention of the conic telescope crown system, the influence of the morphological condition of the inner crown on retention was examined. The usefulness of a milling machine with a polishing disk, a newly developed polishing system, was also evaluated. The results were as follows. 1) In polishing the axial surface of the inner crown of the conic telescope crown system, the milling machine with a polishing disk facilitated specular finishing without causing undercutting in the region from the occlusal surface to the dental cervix. 2) In producing the outer crown of the conic telescope crown system using Deguvest HFG, a phosphate-investing material, the retentive force of the crown tended to increase as the concentration of the solution for specific use was decreased to 50%, 30% and 10%, and reached appropriate levels of 500-1,000 g with the 50% solution. 3) When the height of the inner crown was changed to 2 mm, 4 mm and 6 mm, no significant difference was found in the retentive force, the mean values being 516 g, 836 g and 1,003 g under loading of 10 kg, 20 kg and 30 kg, respectively. 4) The retentive force tended to increase with increased width of the dental cervix of the inner crown: it was 745 g, 1,067 g and 1,376 g at 6 mm, 8 mm and 10 mm of cervical diameter, respectively, under a load of 30 kg. 5) The retentive force was significantly changed with varying loads (99% reliability), and tended to increase with increased load. 6) There was a highly significant correlation between retentive force and sinking of the inner crown. 7) When a tensile load was placed 3 mm lateral to the central axis of a test piece, the retentive force tended to increase when the vertical diameter of the inner crown cervix was larger than the horizontal diameter, while it decreased when the vertical diameter was shorter than the horizontal diameter, as compared with central axis loading.

Crowns↗

Magnetic denture retention systems: inexpensive and efficient.

A magnetic retention system has been used in more than 6000 complete and partial overdentures, sectional dentures and implant overdentures, with excellent clinical results and patient acceptability. For the overdenture application, decoronated, root-treated teeth are fitted with preformed or cast magnetisable alloy root elements, or 'keepers'. Following conventional denture construction, paired cobalt/samarium magnets in a special configuration are cured into the denture base so that with the denture inserted, the magnets grip the root elements with a retentive force of approximately 300 g per root. The paired magnet arrangement eliminates any external magnetic field and doubles the available retention. Magnetic retention has few of the problems encountered with other retention devices. It offers simplicity, low cost, self-adjustment, inherent stress-breaking, automatic repositioning after denture displacement, comparative freedom of lateral denture movement, reduces trauma to retained roots and eliminates the need for adjustment in service. For the sectional denture application, undesirable undercuts on the abutment teeth are used to provide passive, positive retention. The separate buccal and lingual sections are joined together by parallel pins fitting into matching tubes, assembly being maintained by magnetic attraction between a retention element in one section and a keeper in the other. Insertion and removal are more difficult than with a conventional denture but soft tissue coverage is minimal. There are no visible retainer arms and food traps are eliminated. Abutment tooth preparation is negligible, the laboratory procedures simple, and the treatment inexpensive and reversible. A clinical trial of magnetic overdenture retention in conjunction with osseointegrated titanium implants is now in progress. After 21 months acceptable clinical results have been obtained. An improved implant with an alumina core and a sintered hydroxyapatite coating is at present undergoing animal trials. Chemical bonding at the bone/implant interface is anticipated.

Dental Abutments↗

Involvement of amygdala N-methyl-D-asparate receptors in long-term retention of an inhibitory avoidance response in rats.

This study examined the involvement of amygdala N-methyl-D-aspartate (NMDA) receptors in long-term retention of an inhibitory avoidance response. Rats bearing chronic cannulae implanted into the basolateral amygdala were trained on a one-trial inhibitory avoidance task and tested for retention 21 days later. They received intra-amygdala injections of vehicle (Veh) or 0.25, 1.25 or 5.0 micrograms of a competitive NMDA antagonist-2-amino-5-phosphonopentoic acid (AP5) either 5 min before training, immediately after training or 5 min before testing. Results indicated that pretraining intra-amygdala injections of AP5 at all doses impaired retention performance profoundly. Intra-amygdala injections of AP5 immediately after training caused a dose-dependent retention deficit: 0.25 microgram induced no deficit and 5.0 micrograms induced a great deficit. Immediate posttraining intra-amygdala injections of a non-competitive NMDA antagonist MK-801, also impaired retention but MK-801 given 2 hrs after training had no significant effect. In contrast to the marked amnestic effect produced by pre- or posttraining intra-amygdala injections of AP5, intra-amygdala injections of AP5 given just before retention tests had no discernible effect on retention performance. The retention deficit induced by pretraining intra-amygdala injections of 1.25 micrograms AP5 was ameliorated completely by N-methyl-DL-aspartate (0.25 microgram), but also partially by norepinephrine (0.2 microgram) infused into the amygdala immediately after training. However, posttraining infusion 0.2 microgram norepinephrine failed to attenuate significantly the amnestic effect induced by 5.0 micrograms AP5. These findings, taken together, suggest that NMDA receptors in the amygdala are normally involved in memory formation processing of affective experience.

2-Amino-5-phosphonovalerate↗

Some remarks on the epidemiology of acute urinary retention.

Acute urinary retention is an unpleasant, painful experience which requires immediate medical, and frequently surgical intervention. Population studies reveal that acute urinary retention is a common event: a 60 year-old man who survives a further 20 years has a 23 per cent probability of experiencing an acute episode of urinary retention. About half of acute retention episodes appear to be linked to general anaesthesia and a further large population due to the natural history of benign prostatic hyperplasia. The risk of acute urinary retention increases with increasing age. There are a number of other risk factors with risk increased in men with moderate and severe urinary symptoms, low peak urinary flow rates (less than 12 ml/sec) and among men with large prostates. Recent placebo-controlled randomised trials reveal that finasteride is associated with a 57 per cent reduction in the hazard ratio of acute urinary retention when used for at least two years. Since finasteride acts in a positive manner on the major risk factors (finasteride use increases peak urinary flow rate, reduces symptom scores in moderately symptomatic men and reduces prostate volume), this result is not too surprising. It remains to be determined what the risk factors for anaesthesia-induced acute retention are and how they can be altered. Nevertheless, the improvement of our knowledge of the epidemiology of acute urinary retention in the past 12 months is impressive.

Acute Disease↗

Identification of patients at increased risk for prolonged urinary retention following radioactive seed implantation of the prostate.

PURPOSE: Urinary retention is a frequently reported complication following radioactive seed implantation of the prostate. If retention is refractory, a post-implant transurethral prostatic resection may ultimately be required to relieve obstruction, leading to an increased risk of urinary incontinence. In this series the incidence of prolonged urinary retention was determined, and the effect of pretreatment and treatment related factors was analyzed to identify high risk patients. MATERIALS AND METHODS: A total of 251 patients with organ confined prostate carcinoma underwent transperineal prostate seed implantation. Of the patients 114 were implanted with 103palladium (103Pd) and 137 with 125iodine seeds. Of the patients who were implanted with 103Pd 90 received 3 months of neoadjuvant hormonal therapy. All patients had International Prostate Symptom Scores (I-PSS) recorded before implantation to assess the degree of urinary symptoms. In the patients receiving neoadjuvant hormones prostate volumes and I-PSS were recorded before initiation of hormone treatment and 3 months later at the time of implant. RESULTS: Urinary retention developed in 14 patients requiring catheterization for more than 48 hours. Median time to onset was 1 day after implant. Of these patients 6 ultimately required transurethral prostatic resection to relieve urinary obstruction. No patient had urinary incontinence following implantation or transurethral prostatic resection. Multivariate analysis revealed that pretreatment I-PSS, and combined treatment with hormonal therapy and 103Pd predicted for the development of retention. Patients with I-PSS 20 or greater had a 29% risk, I-PSS 10 to 19, 11% risk and I-PSS less than 10, 2% risk of retention. Neither patient age, clinical stage, prostate specific antigen, Gleason score, use of 125I nor prostate volume was significant. A subgroup analysis of patients receiving hormonal therapy and 103Pd revealed that those with persistent urinary symptoms (I-PSS 10 or greater) following 3 months of hormonal therapy had the greatest risk of prolonged retention (37%). CONCLUSIONS: The overall risk of prolonged urinary retention following prostate implantation was low in our series. Using the I-PSS questionnaire, high risk patients can be identified before treatment. Patients with significant pretreatment urinary symptoms or persistent urinary symptoms following 3 months of hormonal therapy and then implantation with 103Pd have the greatest risk.

Aged↗

Relation of fractional 47Ca retention to season and rates of bone loss in healthy postmenopausal women.

Fractional whole-body retention of 47Ca (retention fraction) in 58 healthy postmenopausal women participating in a calcium supplementation trial was examined for seasonal variation and for relationships to rates of bone loss and plasma vitamin D levels. Retention fraction was measured after 18 months in the trial. Bone mineral densities of the radius, femoral neck, and lumbar spine were measured at baseline, 12 months, and 24 months in the trial, and plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] and 25-hydroxyvitamin D (25-OHD) at 12, 18, and 24 months. The adjusted retention (retention fraction adjusted for total calcium intake, smoking status, and log years since menopause) was significantly higher in women evaluated in the months of August through October (mean +/- SD, 19.8 +/- 4.1%, n = 13) than in March through May (mean +/- SD, 17.0 +/- 4.7%, n = 18, p = 0.05). Plasma 25-OHD was associated with retention fraction only in women with low calcium intakes (partial r = 0.69 controlling for total calcium intake and log body mass index, n = 14, p = 0.01). Plasma 1,25-(OH)2D was not related to retention fraction. Adjusted retention, independent of total calcium intake, log years since menopause, smoking status, and season, explained 8% of the variability in the annual change in radius density (partial r = 0.29, p less than 0.05). No significant associations were seen at the spine and femur.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Whole body and regional retention of 99mTc-labeled pyrophosphate at 24 hours: physiological basis of the method for assessing the metabolism of bone in disease.

The retention of 99mTc-labeled pyrophosphate (PPi) at 24 h was measured in 235 patients, 119 of whom had a normal bone metabolism. The mean retention in the group of normal subjects is 52% of the injected dose. Reproducibility of the measurement in a given person is 5.5% coefficient of variation (CV). The value depends strongly on sex (higher in males) and age (higher with increasing age, especially in cortical bone). Retention increases slowly with the decrease in glomerular filtration rate (GFR) between 50 and 120 ml/min; it rises very rapidly with values below 50 ml/min. The slowing down of the GFR with age does not account for the increase in PPi retention with age. When expressed as a percentage of the expected value for sex and age, retention is frequently low in osteoporosis (P less than .001), more so when urinary hydroxyproline is low; it is normal or high in osteomalacia, and in some cases rises after vitamin D treatment is started; it is high in hyperparathyroidism (P less than .01). The PPi retention is correlated with bone calcium accretion rate, alkaline phosphatase level, and above all, the urinary hydroxyproline level. The lower the bone mineralization (Ca/hydroxyproline ratio in biopsy), the higher the retention value. We conclude that the PPi retention is an index of bone metabolism when GFR is higher than 50 ml/min. It allows for classification of metabolic bone diseases according to the bone turnover rate. It has the advantage over the usual biologic examinations in that it affords better observation of highly localized bone disorders and can be used in combination with a morphologic record, the bone scintigraphy.

Adolescent↗

The use of anxiolytic and parasympathomimetic agents in the treatment of postoperative urinary retention following anorectal surgery. A prospective, randomized, double-blind study.

Approximately 30 percent of patients undergoing anorectal surgery will develop acute urinary retention. The cause of this complication is poorly understood. Anxiety, anal distention, bladder distention as a result of vigorous hydration during surgery, and reflex inhibition of the urinary bladder detrusor muscle secondary to pain have been postulated as contributing factors. A four-armed prospective, double-blind, randomized trial was carried out to determine whether an anxiolytic agent (midazolam, 5 mg intramuscularly) and/or a parasympathomimetic agent (bethanechol, 10 mg subcutaneously) reduce the incidence of postoperative urinary retention following anorectal surgery. One hundred thirty-two patients (ages, 18 to 50 years), in acute urinary retention 6 to 12 hours following anorectal surgery, were enrolled. Sixty-nine percent of patients responded to bethanechol. Side effects were minimal. Midazolam alone had no effect on retention. Bethanechol and midazolam in combination resulted in less retention than midazolam and a placebo (P less than 0.05). Bethanechol alone was better than a placebo (P less than 0.002). Mean intraoperative intravenous fluid volume for the entire study group was 900 cc. Initial postoperative urinary volumes of patients who failed the treatment protocol were significantly higher than in those responding to bethanechol (mean of 527 cc vs. 241 cc, P less than 0.001). The use of an anxiolytic agent was not effective in the treatment of postoperative urinary retention. Bladder distention may increase the incidence of urinary retention. Bethanechol, in a dose of 10 mg subcutaneously, significantly lowered the incidence of postoperative urinary catheterization and should be considered as initial treatment of postoperative urinary retention following anorectal surgery.

Acute Disease↗