A total of 235 patients were included in the study (Table 1). The average age of the subjects was 69.9 ± 4.8 years (range 60–90), with 110 subjects aged in the 60 s (46.8%), 118 in the 70 s (50.2%), and 7 aged 80 and over (3.0%). The average BMI was 24.8 ± 3.2 kg/m2 (range 11.9–34.8); there were 5 subjects classified as underweight (2.1%), 112 as having a normal weight (47.7%), 107 as overweight (45.5%), and 11 were defined as having class I obesity (4.7%). Seventy-four people (31.5%) received diabetes treatment, including insulin, and 160 (68.1%) took anti-hypertensive medication. There were 33 patients (14.0%) in ASA class I, 138 (58.7%) in class II, and 64 (27.3%) in class III.
Table 1
Demographic data and perioperative parameters of patients
Patients parameters | Subgroup | Mean ± SD (range) or N (%) |
Age (yrs) | | 69.9 ± 4.8 (60–90) |
| 60–69 | 110 (46.8) |
| 70–79 | 118 (50.2) |
| 80- | 7 (3.0) |
Body mass index (kg/m2) | | 24.8 ± 3.2 (11.9–34.8) |
| < 18.5 | 5 (2.1) |
| 18.5–24.9 | 112(47.7) |
| 25-29.9 | 107 (45.5) |
| 30- | 11 (4.7) |
Diabetes mellitus | No | 161 (68.5) |
| Yes | 74 (31.5) |
Hypertension | No | 75 (31.9) |
| Yes | 160 (68.1) |
ASA classification | class I | 33 (14.0) |
| class II | 138 (58.7) |
| class III | 64 (27.3) |
Urologic history | Group 1 | 68 (28.9) |
| Group 2 | 46 (19.6) |
| Group 3 | 121 (51.5) |
Perioperative parameters | | |
Duration of anesthesia (min) | | 77.9 ± 24.9 (30–160) |
Duration of surgery (min) | | 53.7 ± 24.4 (10–135) |
Amount of fluid administered (ml) | | 784.0 ± 298.8 (200–2000) |
Rate of fluid administration (ml/hr/kg) | | 9.8 ± 4.9 (2.2–33.6) |
Intraoperative fentanyl use | No | 222 (94.5) |
| Yes | 13 (5.5) |
Ephedrine requirement | No | 116 (70.6) |
| Yes | 69 (29.4) |
Intraoperative dexamethasone use | No | 189 (80.4) |
| Yes | 46 (19.6%) |
Postoperative pain score (VAS) | | 2.9 ± 1.9 (0–8) |
Postoperative analgesic use | No | 146 (62.1) |
| Yes | 89 (37.9) |
Data expressed as mean ± SD or frequency (percent of population). Abbreviations: ASA = American Society of Anesthesiologists, N = number of patients, POUR = postoperative urinary retention, VAS = visual analog scale. |
When looking at subjects by group, 68 patients (28.9%) had no history of BPH/LUTS (Group 1), 46 patients (19.6%) had a history of BPH/LUTS but were not currently taking medication (Group 2), and 121 patients (51.5%) were currently receiving medication for BPH/LUTS (Group 3). Group 2 included 1 patient who had undergone TUR-P 10 years previously, and Group 3 included 1 patient who had undergone TUR-P 9 years previously, as well as 2 patients who had undergone TUR-B 1 and 3 years ago.
The average duration of anesthesia was 77.9 ± 24.9 minutes (range 30–160), and the average duration of surgery was 53.7 ± 24.4 minutes (range 10–135). The average total amount of fluid administered was 784.0 ± 298.8 ml (range 200-2,000), and the average rate of fluid administration was 9.8 ± 4.9 ml/hr/kg (range 2.2–33.6). For general anesthesia, propofol was used for induction and desflurane for maintenance of anesthesia. Rocuronium was used for muscle relaxation, and pyridostigmine with atropine and/or glycopyrrolate were used to reverse it. In 13 cases, intravenous fentanyl was used during maintenance. Ephedrine was used as a vasopressor in 69 patients during anesthesia. Dexamethasone was used in 46 cases on request of the anesthetic or surgical teams. There were no patients that required blood transfusion during surgery, and normal saline or balanced crystalloid were used as maintenance fluids.
In the ward, all patients were encouraged to urinate with sufficient time prior to surgery. Postoperatively, the pain score of the surgical site assessed using the VAS averaged 2.9 ± 1.9 (range 0–8). Eighty-nine patients (37.9%) received paracetamol or ketorolac for pain control, and no narcotic analgesics were administered.
Among 235 patients, 50 patients (21.3%) complained of urinary difficulty including hesitation, frequency of urination, and a sense of incomplete bladder emptying. Thirty-five (15.7%) required catheterization due to suprapubic distension accompanied by pain and discomfort, and these patients comprised the POUR group. Twenty-five of these 37 patients did not develop further urinary retention after one episode of catheterization, and 12 were treated more than twice; of these, 5 were treated with an indwelling catheter (1 in Group 2, and 4 in Group 3). All patients received catheterization prior to spontaneously urinating beforehand, except for two patients in Group 3 who had urinary retention after spontaneous voiding. The average amount expelled during catheterization was 682.1 ± 213.1 ml (range: 400-1,200).
The patients with POUR and the remaining 198 patients without POUR were compared statistically (Table 2). Age, body mass index, duration of anesthesia, duration of surgery, total amount of fluid administered, rate of fluid administration, and postoperative pain scores were compared between patients with POUR and without POUR; however, there were no statistically significant differences between variables, including age and BMI, which was associated with a p value of less than 0.1.
Table 2
Perioperative variables in those that did and did not develop postoperative urinary retention
variables | With POUR (N = 37) | Without POUR (N = 198) | P-value |
Age (yr) | 71.4 ± 4.9 | 69.6 ± 4.8 | 0.073 |
Body mass index (kg/m2) | 23.9 ± 2.7 | 24.9 ± 3.2 | 0.071 |
Diabetes treatment | | | 0.272 |
No | 22 (59.5) | 139 (70.2) | |
Yes | 15 (40.5) | 59 (29.8) | |
Hypertension medication | | | 0.375 |
No | 9 (24.3) | 66 (33.3) | |
Yes | 28 (75.7) | 132 (66.7) | |
ASA classification | | | 0.806 |
class I | 4 (10.8) | 29(14.6) | |
class II | 22(59.5) | 116(58.6) | |
class III | 11(29.7) | 53(26.8) | |
Urologic History | | | 0.030 |
Group 1 | 4 (10.8) | 64 (32.3) | |
Group 2 | 9 (24.3) | 37 (18.7) | |
Group 3 | 24 (64.9) | 97 (49.0) | |
Duration of anesthesia (min) | 80.1 ± 25.9 | 77.5 ± 24.7 | 0.380 |
Duration of surgery (min) | 53.2 ± 24.4 | 56.5 ± 24.5 | 0.300 |
Amount of fluid administered (ml) | 836.5 ± 308.1 | 774.2 ± 296.8 | 0.149 |
Rate of fluid administration (ml/hr/kg) | 10.5 ± 5.8 | 9.7 ± 4.7 | 0.371 |
Intraoperative fentanyl use | | | 0.129 |
No | 33 (89.2) | 189 (95.5) | |
Yes | 4 (10.8) | 9 (4.5) | |
Ephedrine requirement | | | 0.52 |
No | 24 (64.9) | 142 (71.7) | |
Yes | 13 (35.1) | 56 (28.3) | |
Intraoperative dexamethasone use | | | 0.737 |
No | 31 (83.8) | 158 (79.8) | |
Yes | 6 (16.2) | 40 (20.2) | |
Postoperative pain score (VAS) | 2.8 ± 2.0 | 2.9 ± 1.9 | 0.571 |
Postoperative analgesic use | | | 0.576 |
No | 25 (67.6) | 121 (61.1) | |
Yes | 12 (32.4) | 77 (38.9) | |
Data expressed as mean ± SD or frequency (percent of population). Abbreviations: ASA = American Society of Anesthesiologists, N = number of patients, POUR = postoperative urinary retention, VAS = visual analog scale. |
Diabetes treatment (yes/no), hypertensive medication (yes/no), ASA classification (I/II/III), Urological history (group 1/2/3), intraoperative fentanyl use (yes/no), ephedrine requirement (yes/no), intraoperative dexamethasone use (yes/no), and postoperative analgesic use (yes/no) were analyzed as univariates, and only urologic history was associated with statistical significance (p = 0.030).
In multiple logistic regression, the odds ratio for age was 1.07 (95% confidence interval 0.98–1.16) and the odds ratio of BMI was 0.89 (95% confidence interval 0.79-1.00), both of which showed no statistical significance. Only urologic history was associated with statistical significance (Table 3); the incidence in Group 1 was 5.9% (4/68), in Group 2 was 19.6% (9/46), and in Group 3 was 19.8% (24/121; Fig. 1). Compared with Group 1, the odds ratio in Group 2 was 3.93 (95% confidence interval 1.18–15.18, p = 0.035), and the odds ratio in Group 3 was 4.61 (95% confidence interval 1.45–13.94, p = 0.008).
Table 3
Logistic regression analysis with urinary retention requiring catheterization as the dependent variable.
| Univariate analysis | Multivariate analysis |
Variable | P-value | OR | 95% CI | P-value | OR | 95% CI |
Age | 0.035 | 1.08 | 1.01–1.16 | 0.116 | 1.07 | 0.98–1.16 |
BMI | 0.073 | 0.90 | 0.81–1.01 | 0.054 | 0.89 | 0.79-1.00 |
Urologic history | | | | | | |
Group 1 | - | 1.00 | - | - | 1.00 | - |
Group 2 | 0.032 | 3.89 | 1.18–15.18 | 0.035 | 3.93 | 1.16–15.73 |
Group 3 | 0.014 | 3.96 | 1.45–13.94 | 0.008 | 4.61 | 1.63–16.76 |
Abbreviations: BMI = body mass index (kg/m2), CI = confidence interval, OR = odds ratio, POUR = postoperative urinary retention.
Overall, the last time that patients in group 2 visited the urology department was 36.9 ± 34.0 months ago (range 2-120) on average; for patients with and without POUR, the interval was 45.3 ± 38.9 months and 34.8 ± 33.0 months, respectively. There was no statistically significant difference (p = 0.3825).
All patients in Group 3 were taking an α-blocker, and 31 of them were taking this together with a 5α-reductase inhibitor. It was possible to confirm the size of the prostate with rectal ultrasound in a total of 84 patients (18 patients with POUR, 66 patients without POUR), and there was no significant difference in the size of the prostate between the two groups (POUR: 32.3 ± 19.0 ml vs without POUR: 34.3 ± 13.7 ml, p = 0.1765).
The parameters of uroflowmetry and the time interval between the uroflowmetry assessment and the operation (TI) were compared in the patients with POUR (N = 10) and without POUR (N = 49) in group 3 (Table 4). In patients with POUR, the average Qmax was 12.7 ± 4.9 ml/sec, which was lower than the 19.9 ± 10.3 ml/sec average in patients without POUR (p = 0.002). Furthermore, the Qavg in patients with POUR was 6.6 ± 2.5 ml/sec lower than the 9.3 ± 3.2 ml/sec in patients without POUR (p = 0.016). There was no statistically significant difference between the two groups with regards to the VV, PVRU, and TI.
Table 4
Comparison between parameters of preoperative uroflowmetry of patients in group 3.
| With POUR (N = 10) | Without POUR (N = 49) | P-value |
Qmax (ml/sec) | 12.7 ± 4.9 | 19.9 ± 10.3 | 0.002 |
Qavg (ml/sec) | 6.6 ± 2.5 | 9.3 ± 3.2 | 0.016 |
VV (ml) | 255.1 ± 80.5 | 305.6 ± 141.9 | 0.479 |
PVRV (ml) | 35.0 ± 28.1 | 32.5 ± 31.0 | 0.642 |
TI (days) | 117.3 ± 102.9 | 182.4 ± 125.0 | 0.122 |
Abbreviations: N = number of patients, PVRV = postvoiding residual urine volume, Qavg = the average urine flow rate, Qmax = the maximal urine flow rate, TI = time interval between examination of uroflowmetry and operation, VV = voided urine volume.