**6.5 Upper tract protection**

Some patients present with bilateral hydronephrosis with or without impairment of renal function. This could be due to vesicoureteral reflux or ureteric strictures. As most patients with ketamine cystitis are young, it is of paramount importance that their upper tract is protected to prevent chronic renal disease. Methods to achieve this include percutaneous nephrostomy and ureteral stenting. Percutaneous nephrostomy involves placing a plastic tube through the skin into the renal pelvis so that the urine produced by the kidney may drain through the tube into an external bag instead of being trapped in the obstructed system. The drainage of the urine through nephrostomy tubes into an external bag also reduces the LUTS from ketamine cystitis, as there is significantly less urine entering the bladder. Disadvantages include inconvenience, as well as nephrostomy tube-related

**Figure 9.** *Clinical pathway for the management of ketamine cystitis (adapted from Ma et al.) [22].*

complications such as frequent dislodgement, and blockage. The inconvenience associated with the use of a nephrostomy tube is due not only to the presence of the tube exiting the loin but also to the bag to which it is connected. Another way of ensuring upper tract drainage is by retrograde stenting [32]. Double J stents can be inserted via a cystoscope to ensure ureteric patency. This method obviates the need for external tubes and bags, but as urine is allowed to flow into the bladder, LUTS may persist. Additionally, some patients may also suffer from stent symptoms, which include LUTS due to the stent tips in the bladder irritating the urothelium.

#### **6.6 Clinical pathway**

Urologists in Hong Kong such as Ma et al. have established a clinical pathway in order to guide and standardise the management of ketamine cystitis [22]. Patients going through such a clinical pathway will receive a full workup of the extent of their ketamine cystitis and complications and receive treatment accordingly (**Figure 9**).

### **7. Challenges**

The treatment of ketamine cystitis revolves heavily around abstinence. However, addiction and withdrawal symptoms, as well as the socioeconomic factors that contribute to the persistence of ketamine abuse, are not the only factors that hamper successful abstinence.

Abstinence from ketamine in the presence of ketamine cystitis is made more difficult by bladder pain and dysuria. As ketamine exhibits analgesic effects, it paradoxically suppresses the bladder pain and dysuria caused by ketamine cystitis. Subsequently, the cessation of ketamine use will unmask more intense cystitis symptoms. If such symptoms are inadequately controlled by more effective analgesics, the patient may be driven to use ketamine as a means to control the cystitis symptoms. Such a pattern of abstinence, failure of symptomatic control, and relapse creates a vicious cycle. It is therefore important to prescribe the patient with adequate analgesia according to the analgesic ladder to effectively suppress bladder pain and dysuria. The flip side of this is that the patient may in turn become dependent on the prescribed analgesics, especially if opioids are used [25].

Failure of abstinence in patients who have received surgical treatment such as augmentation cystoplasty may prove to be detrimental. As mentioned in the Management section, the reabsorption of ketamine and its urinary metabolites via the bowel segment used for augmentation cystoplasty may accelerate damage to the upper urinary tract, making the surgical treatment counterproductive. Correct patient selection for surgical treatment weighs heavily upon the urologist [31].

Upper tract protection by means of bilateral percutaneous nephrostomies (PCNs) may be the last resort for patients with identifiable hydronephrosis and impaired renal function [33]. However, as most ketamine cystitis patients are young and ambulatory, bilateral PCNs prove to be a cumbersome and a general nuisance. Not only are the nephrostomy tubes and bags inconvenient to live with, they also come with issues such as dislodgement or tube blockage. Tube-related issues may require hospitalisation for the revision of the nephrostomies, which adds not only to patient dissatisfaction but also to overall healthcare costs. With such inconvenience, the patient may be deterred from complying with having bilateral PCNs and in turn exposes himself to risks of chronic kidney disease and eventual dialysis dependence. Dialysis dependence in this age group makes the employment difficult, which then contributes to a lack of socioeconomic support and again makes abstinence a challenge.
