Safety and Efficacy of Hyperbaric Oxygen Therapy for the Treatment of Interstitial Cystitis: A Randomized, Sham Controlled, Double-Blind Trial

Mechanistic Rationale and Clinical Efficacy of Hyperbaric Oxygen Therapy in Chronic Neuropathic Pain: An Evidence-Based Narrative Review

Background

Chronic neuropathic pain is a condition affecting an increasing proportion of the general population and its management requires a comprehensive, multidisciplinary program. A growing body of evidence supports the use of hyperbaric oxygen therapy (HBOT) in several chronic neuropathic pain conditions; however, its role and efficacy remain unclear.

Purpose

To summarize current evidence for the mechanistic rationale of HBOT in chronic neuropathic pain conditions and to evaluate its clinical efficacy.

Methods

This narrative review was conducted after searching the following databases (Medline, Embase, Cochrane, PsycINFO, the Web of Science, Scopus, ClinicalTrials. gov, WHO ICTRP, and ProQuest Digital Dissertation) from January 1946 to March 2020. Articles published in English that involved either animal or human studies with acute or chronic neuropathic pain evaluating any HBOT-related intervention were included.

Results

A total of 2971 citations were identified. A total of 29 studies were included in this review. The mechanisms of action for HBOT use in neuropathic conditions included the primary effects of hyperoxia and edema resolution, as well as the secondary effects pertinent to the production of oxygen and nitrogen reactive species (serving as pain signaling molecules), nitric oxide-dependent release of opioid peptides, and reduction of inflammatory mediators. A robust evidence for HBOT use in the clinical setting was associated with chronic regional pain syndrome and chronic primary bladder pain syndrome. Some evidence supported its use for chronic secondary (peripheral) neuropathic pain including radiation-induced plexus neuropathies, postherpetic neuralgia, and trigeminal neuralgia.

Conclusions

HBOT has been shown to have antinociceptive and analgesic effects in animal models of inflammatory, neuropathic, and chronic pain. Human studies demonstrated beneficial effects of HBOT in improving clinical outcomes such as pain scores, pain-related symptoms, and quality of life. A systematic methodology of HBOT application is necessary to confirm its safety and efficacy.

Interventions for treating people with symptoms of bladder pain syndrome: a network meta-analysis

BACKGROUND

Bladder pain syndrome (BPS), which includes the condition of interstitial cystitis, is a poorly understood clinical condition for which patients present with varying symptoms. Management of BPS is challenging for both patients and practitioners. At present, there is no universally accepted diagnosis and diverse causes have been proposed. This is reflected in wide-ranging treatment options, used alone or in combination, with limited evidence. A network meta-analysis (NMA) simultaneously comparing multiple treatments may help to determine the best treatment options for patients with BPS.

OBJECTIVES

To conduct a network meta-analysis to assess the effects of interventions for treating people with symptoms of bladder pain syndrome (BPS).

SEARCH METHODS

We searched the Cochrane Incontinence Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL, in the Cochrane Library), MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and handsearched journals and conference proceedings (searched 11 May 2018) and the reference lists of relevant articles. We conducted a further search on 5 June 2019, which yielded four small studies that were screened for eligibility but were not incorporated into the review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of interventions for treating adults with BPS. All types of interventions (including conservative, pharmacological and surgical) were eligible.

DATA COLLECTION AND ANALYSIS

We assessed the risk of bias of included studies using Cochrane's 'Risk of bias' tool. Primary outcomes were the number of people cured or improved, pain, frequency and nocturia. For each outcome, random-effects NMA models were fitted using WinBUGS 1.4. We monitored median odds ratios (ORs) for binary outcomes and mean differences (MDs) for continuous outcomes with 95% credible intervals (Crls). We compared results of the NMA with direct evidence from pairwise meta-analysis of head-to-head trials. We used the CINeMA tool to assess the certainty of evidence for selected treatment categories.

MAIN RESULTS

We included 81 RCTs involving 4674 people with a median of 38 participants (range 10 to 369) per RCT. Most trials compared treatment against control; few trials compared two active treatments. There were 65 different active treatments, and some comparisons were informed by direct evidence from only one trial. To simplify, treatments were grouped into 31 treatment categories by mode of action. Most studies were judged to have unclear or high risk of bias for most domains, particularly for selection and detection bias. Overall, the NMA suggested that six (proportion cured/improved), one (pain), one (frequency) and zero (nocturia) treatment categories were effective compared with control, but there was great uncertainty around estimates of effect. Due to the large number of intervention comparisons in this review, we focus on three interventions: antidepressants, pentosan polysulfate (PPS) and neuromuscular blockade. We selected these interventions on the basis that they are given 'strong recommendations' in the EAU Guidelines for management of BPS (EAU Guidelines 2019). We found very low-certainty evidence suggesting that antidepressants were associated with greater likelihood of cure or improvement compared with control (OR 5.91, 95% CrI 1.12 to 37.56), but it was uncertain whether they reduced pain (MD -1.27, 95% CrI -3.25 to 0.71; low-certainty evidence), daytime frequency (MD -2.41, 95% CrI -6.85 to 2.05; very low-certainty evidence) or nocturia (MD 0.01, 95% CrI -2.53 to 2.50; very low-certainty evidence). There was no evidence that PPS had improved cure/improvement rates (OR 0.14, 95% CrI 0.40 to 3.35; very low-certainty evidence) or reduced pain (MD 0.42, 95% CrI -1.04 to 1.91; low-certainty evidence), frequency (MD -0.37, 95% CrI -5.00 to 3.44; very low-certainty evidence) or nocturia (MD -1.20, 95% CrI -3.62 to 1.28; very low-certainty evidence). There was evidence that neuromuscular blockade resulted in greater cure or improvement (OR 5.80, 95% CrI 2.08 to 18.30) but no evidence that it improved pain (MD -0.33, 95% CrI -1.71 to 1.03), frequency (MD -0.91, 95% CrI -3.24, 1.29) or nocturia (MD -0.04, 95% CrI -1.35 to 1.27). The certainty of this evidence was always very low.

AUTHORS' CONCLUSIONS

We are uncertain whether some treatments may be effective in treating patients with BPS because the certainty of evidence was generally low or very low. Data were available for a relatively large number of trials, but most had small sample sizes and effects of treatments often could not be estimated with precision. An NMA was successfully conducted, but limited numbers of small trials for each treatment category hampered our ability to fully exploit the advantages of this analysis. Larger, more focused trials are needed to improve the current evidence base.

[Diagnosis and treatment of interstitial cystitis (IC/PBS) : S2k guideline of the German Society of Urology]

In this review article, the authors describe all relevant aspects of the new S2k guideline from the German Society of Urology (Deutschen Gesellschaft für Urologie, DGU) for the diagnosis and treatment of IC/PBS (interstitial cystitis/painful bladder syndrome). A list of necessary and optional examinations and the necessity of diagnosis of exclusion are summarized and evaluated. The treatment options listed (ranging from conservative, oral drug, and complementary medicine to interventional surgical procedures) also give the reader a good overview of the contents of the guideline and possible therapeutic approaches. Finally, the recommendations including consensus of the guideline group are also summarized in various information boxes.

[Diagnosis and treatment of interstitial cystitis (IC/PBS) : S2k guideline of the German Society of Urology]

In this review article, the authors describe all relevant aspects of the new S2k guideline from the German Society of Urology (Deutschen Gesellschaft für Urologie, DGU) for the diagnosis and treatment of IC/PBS (interstitial cystitis/painful bladder syndrome). A list of necessary and optional examinations and the necessity of diagnosis of exclusion are summarized and evaluated. The treatment options listed (ranging from conservative, oral drug, and complementary medicine to interventional surgical procedures) also give the reader a good overview of the contents of the guideline and possible therapeutic approaches. Finally, the recommendations including consensus of the guideline group are also summarized in various information boxes.

Hyperbaric oxygen significantly improves frequent urination, hyperalgesia, and tissue damage in a mouse long-lasting cystitis model induced by an intravesical instillation of hydrogen peroxide

AIM

To investigate whether hyperbaric oxygen (HBO) is effective for the pathophysiological findings in an IC/PBS-like mouse model induced by intravesical hydrogen peroxide (H₂ O₂ ).

METHODS

Six-week-old ICR female mice (N = 16) were divided into four experimental groups: (1) sham control with intravesical vehicle instillation twice, and without subsequent treatment (N = 4); (2) H₂ O₂ instillation twice, followed by HBO (100% O₂ , 2 ATA, 30 min per session) (N = 4); (3) H₂ O₂ instillation twice, followed by dummy hyperbaric treatment (air, 2ATA, 30 min per session) (N = 4); and (4) H₂ O₂ instillation twice, followed by no treatment (N = 4). Body weight, voiding frequency, tidal voiding volume, and individual bladder pain threshold using the von-Frey test were measured. Whole body uptake of an inflammation-specific fluorescent pan-cathepsin was assessed by an in vivo imaging. Immunohistochemical staining and the mRNA expression of several biomarkers associated with chronic inflammation in resected bladders were evaluated.

RESULTS

The HBO-treated group showed significant improvement in voiding frequency, tidal voiding volume, and the individual bladder pain threshold. Moreover, HBO markedly suppressed H₂ O₂ -induced inflammation, edema, and fibrosis in bladder wall, concomitant with a significant decrease in mRNA expressions of inflammation biomarkers and a significant increase in endothelial nitric oxide synthase expression. HBO also inhibited the expression of transient receptor potential channels induced by H₂ O₂ instillation.

CONCLUSION

These results suggest that HBO contributes to elimination of H₂ O₂ -induced long-lasting cystitis through the repair of chronically inflamed bladder tissue and inhibition of the bladder sensory system.

Double-blind trials in hyperbaric medicine: A narrative review on past experiences and considerations in designing sham hyperbaric treatment

Background

Hyperbaric oxygen therapy, which consists of breathing 100% oxygen under a higher atmospheric pressure than normal, is utilized worldwide in the treatment of several diseases. With the growing demand for evidence-based research, hyperbaric oxygen therapy has been criticized for delivering too little high-quality research, mainly in the form of randomized controlled trials. While not always indispensable, the addition of a sham-controlled group to such a trial can contribute to the quality of the research. However, the design of a sham (hyperbaric) treatment is associated with several considerations regarding adequate blinding and the use of pressure and oxygen. This narrative review discusses information on the sham profile and the blinding and safety of double-blind trials in hyperbaric medicine, irrespective of the indication for treatment.

Methods

MEDLINE, Embase and CENTRAL were searched for sham-controlled trials on hyperbaric oxygen therapy. The control treatment was considered sham if patients were blinded to their allocation and treatment took place in a hyperbaric chamber, with no restrictions regarding pressurization, oxygen levels or indication. Studies involving children or only one session of hyperbaric oxygen were excluded. Information on (the choice of) treatment profile, blinding measures, patient’s perception regarding allocation and safety issues was extracted from eligible studies.

Results

A total of 42 eligible trials were included. The main strategies for sham treatment were (1) use of a lower pressure than that of the hyperbaric oxygen group, while breathing 21% oxygen; (2) use of the same pressure as the hyperbaric oxygen group, while breathing an adjusted percentage of oxygen; and (3) use of the same pressure as the hyperbaric oxygen group, while breathing 21% oxygen. The advantages and disadvantages of each strategy are discussed using the information provided by the trials.

Conclusion

Based on this review, using a lower pressure than the hyperbaric oxygen group while breathing 21% oxygen best matches the inertness of the placebo. Although studies show that use of a lower pressure does allow adequate blinding, this is associated with more practical issues than with the other strategies. The choice of which sham profile to use requires careful consideration; moreover, to ensure proper performance, a clear and detailed protocol is also required.

Hyperbaric oxygen as a treatment modality in cyclophosphamide-induced hemorrhagic cystitis

Late-onset HC is a well-recognized complication associated with cyclophosphamide/acrolein-induced toxicity. It poses a management challenge when hyperhydration and bladder irrigation do not result in clinical improvement as desired. The data regarding use of hyperbaric oxygen therapy (HBO2) as an early treatment modality in this clinical setting are limited. We present 2 cases, that were refractory to hyperhydration and bladder irrigation but responded to HBO2. They were treated with 20-30 daily sessions over weekdays with 100% oxygen for 90 minutes at 2 atmospheric pressure units (2 atm). Both patients reported improved symptoms within the first 15 sessions, and hematuria diminished by 20 sessions. Hyperbaric oxygen is a less invasive, outpatient therapy that is effective for treatment of HC and is tolerated well by young patients.

Clinical utility of hyperbaric oxygen therapy in genitourinary medicine

Hyperbaric oxygen therapy (HBOT) is a medical technique which delivers oxygen at ambient pressures to increase the amount of dissolved oxygen in the blood and oxygen distribution to tissues. There are several beneficial properties of HBOT concomitant with elevated oxygen distribution in tissue including anti-inflammation, angiogenesis through vascular endothelial growth factor proliferation, augmented fibroblast activity through fibroblast growth factor proliferation, tissue and wound repair, enhancement of lymphocyte and macrophage activity, increased male testosterone secretion, and bactericidal activity. Given its renown in treating conditions such as decompression sickness and carbon monoxide poisoning, HBOT is making gradual strides for use in genitourinary medicine due to its low risk and likeliness to achieve favorable results. Early success has been observed in the treatment of Fournier's gangrene, radiation cystitis, and interstitial cystitis via the elimination of clinical symptoms such as pain. Further indications that have exhibited positive outcomes despite HBOT's ambiguous mechanism of action include cyclophosphamide hemorrhagic cystitis, emphysematous cystitis, pelvic radiation disease, radiation-induced proctopathy, dystrophic calcification of the prostate, erectile dysfunction secondary to urethroplasty, priapism, abnormal renal morphology, blood testosterone, calcific uremic arteriolopathy, and hidradenitis suppurativa. For other indications, multicenter studies must be conducted to determine HBOT's true efficacy, mechanism of action, risks, and advantages over conventional treatments.

The potential long-term neurological improvement of early hyperbaric oxygen therapy on hemorrhagic stroke in the diabetics

AIMS

Although Hyperbaric oxygen therapy (HyperBOT) attract our attention successfully these days, it is still full of controversy on the treatment of acute stroke. The aim of this study is to assess the potential long-term neurological consequences and safety of using HyperBOT on intracerebral hemorrhage (ICH) in the diabetics.

METHODS

In this prospective, randomized controlled trial, 79 diabetes patients suffering from acute ICH were randomized to treat for 60 min in a monoplace hyperbaric chamber pressurized with pure oxygen to 2.5-atm absolute (ATA) in the HyperBOT group or 1.5 ATA in the normobaric oxygen therapy (NormBOT) group, which was performed as control. Both short-term and long-term neurological consequences were studied and compared in each group on National Institutes of Health Stroke Scale [NIHSS], Barthel Index, modified Rankin Scale [mRS] and Glasgow Outcome Scale [GOS]. The related complications or side-events of all patients were recorded as well at the final follow-up of six months after onset.

RESULTS

No distinct difference was observed between each group at one month follow-up. However, in the long-term follow-up of six months, a higher frequency of patients in the HyperBOT group resulted into good outcome with a relative high neurological consequence compared with the NormBOT group (Barthel Index: 85.1% versus 65.6%, P = 0.080; mRS: 89.4% versus 68.8%, P = 0.045; GOS: 83.0% versus 62.5%, P = 0.073; NIHSS: 80.9% versus 56.2%, P = 0.035).

CONCLUSIONS

Early HyperBOT was found to be safe and effective with regards to the long-term neurological outcome of diabetic patients suffering from ICH.

Can Hyperbaric OxygenTherapy (HOT) have a Place in the Treatment of some Urological Diseases?

HOT (Hyperbaric Oxygen Therapy) is used in urological diseases: Scrotal/perineal fasciitis and Radiation-induced cystitis (and proctopathy); in urgency and frequency syndrome and with chronic pelvic pain the use of HOT is still experimental.

The basic principle of HOT is to increase oxygen dissolved in the blood when it is administered at high pressure. 02 is then distributed to the tissues through the pressure gradient; tissue hyper-oxygenation has anti-inflammatory and pain-killing effects, it increases bacterial permeability to antibiotics, strengthens neo-angiogenesis, reinforces lymphocytes and macrophages function, augments testosterone secretion (in males), and finally enhances wound healing process.

We treated with HOT (integrating other treatments) 17 cases of necrotizing fasciitis, 13 radiation-induced cystitis and 4 cases of urgency and frequency syndrome. We always had good results, with a good cleansing of the dissected areas in Fournier's gangrene; in the cases of radiation-induced cystitis we had an improvement in the symptoms and hematuria, and finally in cases of urgency and frequency syndrome we had a transient reduction of symptomatology and pain.

Our experiences and the specific literature on this subject suggest that HOT, sometimes associated with other medical and surgical therapies, can be an effective tool to treat urological diseases; in some cases its efficacy was well demonstrated (Fournier's gangrene and Radiation-induced cystitis), in others (urgency-frequency syndrome and chronic pelvic pain) it is a promising technique which definitely needs further research.

Treatment of ulcerative compared to non-ulcerative interstitial cystitis with hyperbaric oxygen: a pilot study

Background

The etiology of interstitial cystitis (IC) is often idiopathic but can be due to Hunner's ulcers. Hyperbaric oxygen (HBO) is used to treat ulcerative disease of the superficial skin. We hypothesized that HBO can treat ulcerative IC (UIC) but would be less efficacious for non-ulcerative IC (NIC).

Methods

Patients with NIC and UIC enrolled in this study. Following informed consent, demographic information was collected. A visual analog pain scale and validated questionnaires were collected; each patient underwent cystoscopy prior to treatment. Each subject met with a hyperbaric specialist and after clearance underwent 30 treatments over 6 weeks. Adverse events were monitored. Patients repeated questionnaires, visual analog pain scale and global response assessment (GRA) immediately, 2 weeks, 3, 6 and 12 months after treatment. Patients also underwent cystoscopy 6 months after treatment. Differences before and after treatment were compared.

Results

Nine patients were recruited to this study. One was unable to participate, leaving two subjects with NIC and six with UIC. All patients completed HBO without adverse events. Three patients completed HBO but pursued other therapies 7, 8.5 and 11 months after treatment. On GRA, 83% of patients with UIC were improved. This treatment effect persisted, as 66% of UIC patients remained better at 6 months. In contrast, only one patient in the NIC group improved. Questionnaire scores improved in both groups. Pain scores improved by 2 points in the UIC group but worsened by 1.5 points in the NIC group. Two patients with ulcers resolved at 6-month cystoscopy.

Conclusion

HBO appeared beneficial for both UIC and NIC. Data shows slightly better benefit in patients with UIC compared to NIC; both groups showed improvement. Given the small sample size, it is difficult to draw definitive conclusions from these data. Larger studies with randomization would be beneficial to show treatment effect.

Successful Treatment of Lower Limb Complex Regional Pain Syndrome following Three Weeks of Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy (HBOT) is a treatment that delivers 100% oxygen at increased atmospheric pressures. The efficacy of HBOT for treating pain has been described in various animal pain models and may have clinical efficacy in the treatment of human chronic pain syndromes. We present our experience with posttraumatic Complex Regional Pain Syndrome (CRPS) type 2 in a patient who underwent 15 sessions of HBOT. A 41-year-old male with one-year history of CRPS of left foot followed by left ankle fracture demonstrated less pain, decreased swelling, less allodynia, and improvement in skin color and range of motion of the lower limb after 3 weeks of HBOT. Patient was back to work for the first time in over a year. HBOT may be considered as a valuable therapeutic tool in the treatment of long-standing CRPS.

Variations in the reporting of outcomes used in systematic reviews of treatment effectiveness research in bladder pain syndrome

This paper investigates the quality of outcomes reported in systematic reviews and randomised controlled trials (RCTs) of bladder pain syndrome and its relationship with study quality and journal impact factor. We searched until August 2013 the Cochrane Library, EMBASE, Medline, CINAHL, LILACS and SIGLE, without language restrictions. Quality of outcome reporting in systematic reviews and constituent RCTs was assessed using a 6-point scale. Overall study quality was assessed using the AMSTAR and Jadad scoring systems, and impact factor in the year of publication was noted. Spearman's rank correlation was calculated. There were 8 systematic reviews, with a total of 28 RCTs (1732 patients), reporting 5 outcomes using 19 different measurement scales. The outcomes reported in individual RCTs were urinary symptoms (100%), pain (64%), quality of life (39%), general wellbeing (36%) and bladder capacity (36%). The mean quality of outcomes reported was 1.63 (95% CI 0.29-2.96) for systematic reviews and 3.25 (95% CI 2.80-3.70) for RCTs. The quality of outcomes reported showed correlation with overall study quality (0.90, 95% CI 0.79-0.95, p<0.0001) but not with journal impact factor (0.07, 95% CI -0.31-0.43, p=0.35). Multivariable linear regression showed a relationship between quality of outcome reporting and study quality (β=0.05, p<0.0001), adjusting for effects of study type, impact factor and journal type. There is a need to generate consensus over a set of core outcomes in bladder pain syndrome using standardised reporting tools and to disseminate these through good publication practice.

The effect of hyperbaric oxygen on symptoms after mild traumatic brain injury

In this single-center, double-blind, randomized, sham-controlled, prospective trial at the U.S. Air Force School of Aerospace Medicine, the effects of 2.4 atmospheres absolute (ATA) hyperbaric oxygen (HBO₂) on post-concussion symptoms in 50 military service members with at least one combat-related, mild traumatic brain injury were examined. Each subject received 30 sessions of either a sham compression (room air at 1.3 ATA) or HBO₂ treatments at 2.4 ATA over an 8-week period. Individual and total symptoms scores on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) and composite scores on Post-traumatic Disorder Check List-Military Version (PCL-M) were measured just prior to intervention and 6 weeks after completion of intervention. Difference testing of post-intervention means between the sham-control and HBO₂ group revealed no significant differences on the PCL-M composite score (t=-0.205, p=0.84) or on the ImPACT total score (t=-0.943, p=0.35), demonstrating no significant effect for HBO₂ at 2.4 ATA. PCL-M composite scores and ImPACT total scores for sham-control and HBO(2) groups revealed significant improvement over the course of the study for both the sham-control group (t=3.76, p=0.001) and the HBO₂ group (t=3.90, p=0.001), demonstrating no significant HBO₂ effect. Paired t-test results revealed 10 ImPACT scale scores in the sham-control group improved from pre- to post-testing, whereas two scale scores significantly improved in the HBO₂ group. One PCL-M measure improved from pre- to post-testing in both groups. This study showed that HBO₂ at 2.4 ATA pressure had no effect on post-concussive symptoms after mild TBI.

The use of hyperbaric oxygen for treating delayed radiation injuries in gynecologic malignancies: a review of literature and report of radiation injury incidence

PURPOSE

The purposes of this paper are to review the best evidence supporting the use of hyperbaric oxygen therapy (HBOT) in delayed radiation injuries in gynecologic malignancies and report the incidence of radiation injuries at two large medical centers in southeastern Wisconsin.

METHODS

A literature search was performed on Google Scholar, PubMed, and Ovid for studies evaluating the use of HBOT radiation cystitis, proctitis, and necrosis. The studies were then reviewed for the highest quality evidence using American Academy of Neurology guidelines. To evaluate radiation injuries, cancer databases at Froedtert Memorial Lutheran Hospital (FMLH) and Aurora St. Luke's Hospital (ASLH) were accessed.

RESULTS

Several studies support the use of HBOT in treating radiation cystitis, proctitis, and necrosis, with proctitis having the strongest evidence in its favor. The average annual incidence of radiation injury at FMLH was 13.8%. Patients with cervical cancer and vulvar cancer had rates of 23% each. The average annual incidence of radiation injury among gynecologic cancer patients at ASLH was 5.5%.

CONCLUSIONS

There is level A evidence for using HBOT to treat radiation proctitis. There is level B evidence for using HBOT to treat radiation cystitis and necrosis. The incidence delayed radiation injuries can be as high as 23%. This has relevance in practice guidelines for the treatment of delayed radiation injuries in gynecologic malignancies.

Contemporary management of the painful bladder: a systematic review

CONTEXT

Different types of behavioural, dietary, interventional, pharmacologic, and surgical therapies have been used to treat painful bladder syndrome/interstitial cystitis (PBS/IC). Because of the paucity of randomised placebo-controlled studies on different treatments, an evidence-based management approach has not yet been developed.

OBJECTIVE

To critically review and synthesize data from a wide range of current therapeutic approaches to PBS/IC, to quantify the effect size from randomised controlled trials (RCTs), and to reach clinical agreement on the efficacy of treatments for PBS/IC.

EVIDENCE ACQUISITION

We performed a systematic review of the literature to identify articles published between 1990 and September 2010 on the management of PBS/IC. We included articles restricted to the English language published since 1990 to date that reported on oral and intravesical treatment, multimodal or combined treatment, and surgical treatment. For all RCTs, standardised mean differences (SMDs) were extracted and combined in a meta-analysis applying a random-effect model that incorporated the heterogeneity of effects. The four outcomes assessed in all studies were a change in the Interstitial Cystitis Symptom Index (ICSI), pain, urgency, and frequency. Non-RCTs (nRCTs) were analysed with a narrative synthesis of the evidence from all research designs.

EVIDENCE SYNTHESIS

We included 7709 adult patients from 29 RCTs and 57 nRCTs. Meta-analysis of RCTs showed that only cyclosporine A provided a simultaneous great effect size of SMD on ICSI, pain, and frequency. Amitriptyline at different dosages showed a great effect size of SMD on pain and urgency or on ICSI and frequency. The remaining RCTs showed sporadic significant changes in only one of the four considered parameters. The attributed levels of evidence for treatments reported in RCTs were 1b; grades of recommendations ranged from A to C. According to the Jadad score, 11 RCTs were high-quality studies. Meta-analysis of RCTs showed a great heterogeneity in the applied methodologies, clinical outcomes assessed, and the obtained results in different studies. The results from the nRCTs showed that the most frequently adopted treatment is oral pentosan polysulfate and that the use of botulinum A toxin intradetrusorial injections in PBS/IC is increasing. A high heterogeneity in drugs and treatment modalities, clinical outcomes, and obtained results was also found for nRCTs.

CONCLUSIONS

Limited evidence exists for the few treatments for PBS/IC. The lack of definitive conclusions is due to the great heterogeneity in methodology, symptoms assessment, duration of treatment, and follow-up in both RCTs and nRCTs.

Hyperbaric oxygen therapy for painful bladder syndrome/interstitial cystitis resistant to conventional treatments: long-term results of a case series in Japan

Background

There is no confirmed strategy for treating painful bladder syndrome/interstitial cystitis (PBS/IC) with unclear etiology. Therefore, a pilot study was carried out to evaluate the efficacy and safety of hyperbaric oxygen (HBO) therapy in treatment-resistant PBS/IC patients.

Methods

HBO treatment (2.0 ATA for 60 minutes/day × 5 days/week for 2 or 4 weeks) was performed on 11 patients with severe symptoms that had not been improved by previous therapy regimens between December 2004 and July 2009.

Results

Seven of the 11 patients demonstrated persistent improvement in symptoms during the 12 months after HBO treatment. These responders demonstrated a decrease in the pelvic pain scale and urgency scale from 7.7 ± 1.0 and, 6.6 ± 0.9 to 3.4 ± 2.5 and 4.3 ± 2.4 after 12 months, respectively (p < 0.05). The total score of the interstitial cystitis symptom index and 24-hour urinary frequency demonstrated a significant sustained decrease from the baseline. Two responders, who received an additional course of HBO 12 and 13 months after initial treatment, respectively, did not suffer impairment for more than two years. There was one case of transient eustachian tube dysfunction and three cases of reversible exudative otitis media as a consequence of HBO treatment.

Conclusions

HBO is a potent treatment for PBS/IC patients resistant to conventional therapy. It was well tolerated and provided maintained amelioration of pain, urgency and urinary frequency for at least 12 months.

Interstitial cystitis: an unsolved enigma

Painful bladder syndrome/interstitial cystitis (PBS/IC) is a chronic disease of unknown etiology characterized by vague bladder pain and nonspecific urinary symptoms, such as urgency and frequency. Although it was initially considered to be a rare condition, its prevalence has significantly increased, possibly because of different definitions used and greater physician awareness. Because of the multiple diagnostic criteria used, there is significant variation in its prevalence. In addition, there is often a delay in the diagnosis of PBS/IC. It affects predominantly women of middle age, and it significantly decreases quality of life. Diagnosis of PBS/IC is mainly a diagnosis of exclusion; there are no characteristic symptoms or pathognomonic findings. Therefore, it is important to rule out diseases that have a similar clinical picture (i.e., urinary infections, bladder carcinoma) but definite therapies and worse prognosis if left untreated. PBS/IC management suffers from lack of evidence; many therapies are empiric or based on small studies and case series. Treatment includes supportive therapies (psychosocial, behavioral, physical), oral treatments, and intravesical treatments, whereas other more invasive treatments such as electric neuromodulation and reconstructive surgery are reserved for refractory cases. Physicians should always keep in mind the diagnosis of PBS/IC in patients presenting with chronic urinary symptoms after excluding other more common diseases.

What is new in bladder pain syndrome/interstitial cystitis?

PURPOSE OF REVIEW

Bladder pain syndrome/interstitial cystitis is an important and poorly understood disorder. This review highlights current research findings that may be of benefit to the clinician who is responsible for the diagnosis and treatment of patients who suffer from this condition.

RECENT FINDINGS

The perspective from which we view bladder pain syndrome/interstitial cystitis is evolving, as is apparent in the literature this year. It is best perceived as one of many chronic pain syndromes, some of which may be related. International efforts aimed at consistent definition and nomenclature are ongoing. Some new treatments have been reported that may be of benefit.

SUMMARY

In the age of the internet, it is incumbent upon the clinician to keep up with current ideas, epidemiology, and treatment findings to be able to discuss these with well informed patients who come to clinics around the world. In this review we hope to bring practicing healthcare providers up to date with the literature on bladder pain syndrome/interstitial cystitis, and the implications for their patients.

Pharmacologic management of painful bladder syndrome/interstitial cystitis: a systematic review

BACKGROUND

More than 180 different types of therapy have been used in the treatment and management of painful bladder syndrome/interstitial cystitis (PBS/IC), yet evidence from clinical trials remains inconclusive. This study aimed to evaluate the efficacy of pharmacologic approaches to PBS/IC, to quantify the effect size from randomized controlled trials, and to begin to inform a clinical consensus of treatment efficacy for PBS/IC.

METHODS

We identified randomized controlled trials for the pharmacologic treatment of patients with PBS/IC diagnosed on the basis of National Institute of Diabetes and Digestive and Kidney Diseases or operational criteria. Study limitations include considerable patient heterogeneity as well as variability in the definition of symptoms and in outcome assessment.

RESULTS

We included a total of 1470 adult patients from 21 randomized controlled trials. Only trials for pentosan polysulfate sodium had sufficient numbers to allow a pooled analysis of effect. According to a random-effects model, the pooled estimate of the effect of pentosan polysulfate therapy suggested benefit, with a relative risk of 1.78 for patient-reported improvement in symptoms (95% confidence interval, 1.34-2.35). This result was not heterogeneous (P = .47) and was without evidence of publication bias (P = .18). Current evidence also suggests the efficacy of dimethyl sulfoxide and amitryptyline therapy. Hydroxyzine, intravesical bacille Calmette-Guérin, and resiniferatoxin therapy failed to demonstrate efficacy, but evidence was inconclusive owing to methodological limitations.

CONCLUSIONS

Pentosan polysulfate may be modestly beneficial for symptoms of PBS/IC. There is insufficient evidence for other pharmacologic treatments. A consensus on standardized outcome measures is urgently needed.