in postoperative retention more than 6 hours have elapsed since last voiding and the patient is unable to void despite encouragement and analgesics (opiods suppress voiding).
Suprapubic cystostomy is recommended as the first procedure if
the retention is large (above 1000 ml according to ultrasonography or the bladder reaches the navel)
the patient has a complicated urethral stricture
a large prostate has caused difficulties in catheterization earlier
or if recurrent retention occurs after treatment with single catheterization.
Anticoagulant therapy is not an absolute contraindication to cystostomy, but it increases the risk of bleeding.
Alternatives include bridging therapy, pause or indwelling catheter or education on in-and-out self-catheterization (in the case of urinary retention, in-and-out catheterization will usually not suffice).
The cystostomy catheter can be removed when voiding is repeatedly successful and the residual urine is less than 200 ml. The patient should be given clear instructions on bladder training by regular closing of the catheter.
The whole volume can be emptied at one time. In a cardiac patient who is in poor general condition, however, the bladder should be emptied slowly, over about 15 minutes, in order to prevent excessive venous return from the pelvis. In the final phase of emptying, the urine may be bloody because of small tears on the bladder mucosa caused by over-distension. The blood in the urine will usually disappear with time.
In most cases (80%) of BPH-related retention the episode is the first occurrence of retention and therefore warrants follow-up.
A cleanly voided urine specimen and bacterial culture should be taken from all patients.
No other investigations are necessary if the patient had his first retention and there is a predisposing factor, e.g. alcohol, exposure to cold, postoperative state, or bed rest associated with an acute illness.
If an increase of plasma creatinine concentration during retention was due to obstruction it normalizes rapidly.
Retention and catheterization raise PSA concentration. If the value is elevated, it should be controlled after 4-6 weeks.
Further urological investigations are indicated in recurrent urinary retention.
References
Bengtsen MB, Farkas DK, Borre M et al. Acute urinary retention and risk of cancer: population based Danish cohort study. BMJ 2021;375():n2305. [PubMed]
Karavitakis M, Kyriazis I, Omar MI et al. Management of Urinary Retention in Patients with Benign Prostatic Obstruction: A Systematic Review and Meta-analysis. Eur Urol 2019;75(5):788-798. [PubMed]