Lignocaine and ulcerative proctitis

Managing intractable proctitis and the problematic pouch

Proctitis accounts for a significant proportion of cases of ulcerative colitis (UC), and some patients subsequently develop more extensive disease. However, most patients continue to have limited inflammation, although the changes in the distal colon and rectum can occasionally be severe, and symptoms of increased frequency, rectal bleeding and urgency can be as disabling as they are for patients with more extensive colitis. Furthermore, although symptoms are typically well controlled with standard medications, medically refractory proctitis poses particular problems. Patients generally are not systemically unwell, and there is no added fear of cancer. Therefore, the prospect of colectomy for such limited disease is resisted by patients, physicians and surgeons alike. Unusual therapies, often delivered locally by enema or suppository, have been tested in small case series without definitive outcomes. The pathogenesis of such limited, yet intractable inflammation remains unclear, and the differential diagnosis should be carefully reviewed to ensure that local disease, whether it is infectious, vascular, or a result of injury or degeneration, is not overlooked. Ileo-anal pouch formation is the surgery of choice for about 20% of patients with UC who undergo colectomy. In the majority of cases, this surgery results in an acceptable quality of life and freedom from a stoma. However, in a sizeable minority of cases, pouch dysfunction can cause intractable problems. The causes of pouch dysfunction are varied and must all be considered carefully, particularly in refractory cases. Pouchitis is a common issue and is usually transient and easily treated. However, refractory and chronic pouchitis can be challenging. Ischaemia, injury, infection and Crohn's disease can all cause refractory pouch dysfunction. In a minority of cases, there appears to be no apparent organic pathology, and the presumptive diagnosis is that of a functional pouch disorder. Although it is much rarer, neoplastic changes in the pouch must also be considered, and the risk managed appropriately. The management of both intractable proctitis and the problematic pouch is made more challenging by the wide differential diagnosis that must be considered and by the paucity of high-quality clinical trials to support any one therapy. Key strategies to overcoming these limitations include methodical and systematic investigation and review, and a willingness to tailor therapy to the individual patient. Clinical trials of new treatments should be supported, and data from the experience with small cohorts of patients should be meticulously collected, critically analysed and widely disseminated.

Topical agents for idiopathic distal colitis and proctitis

Rectally administered topical agents have demonstrated efficacy in the maintenance of distal colitis (DC) and proctitis and as they are rarely associated with significant blood drug levels, side effects are infrequent. The topical 5-aminosalicylic acid (5-ASA) suppositories and enemas target different regions of the distal colon and are effective for proctitis and DC, respectively. They demonstrate clinical results that are better than oral 5-ASAs and are preferred to topical steroids with better clinical, endoscopic and histological outcomes, without the risk of adrenal suppression. Disease resistant to topical agents, however, can be extremely difficult to manage. The addition of oral 5ASAs, steroids, immunosuppressants and the anti-tumor necrosis factor-α agents may be effective, but can result in significant side effects and not all patients will respond to the therapies. It is for these patients that new and novel therapies are required. Novel topical agents have been proposed for the management of resistant DC. These agents included butyrate, cyclosporine, and nicotine enemas, as well as tacrolimus suppositories, and tacrolimus, ecabet sodium, arsenic, lidocaine, bismuth, rebamipide and thromboxane enemas. While some of these agents appear to demonstrate impressive outcomes, the majority have only been examined in small open-labeled studies. There is thus a desperate need for more randomized double-blinded placebo controlled studies to investigate the clinical utility of these topical therapies. This review summarizes the efficacy of the established topical therapies, and explores the available data on the new and novel topical agents for the management of DC and proctitis.

Novel topical therapies for distal colitis

Distal colitis (DC) can be effectively treated with topical 5ASA agents. Suppositories target the rectum while enemas can reliably reach the splenic flexure. Used in combination with oral 5ASAs, the control of the inflammation is even more effective. Unfortunately, resistant DC does occur and can be extremely challenging to manage. In these patients, the use of steroids, immunosuppressants and the anti-tumor necrosis factor α agents are often required. These, however, can be associated with systemic side effects and are not always effective. The investigation of new topical therapeutic agents is thus required as they are rarely associated with significant blood drug levels and side effects are infrequent. Some of the agents that have been proposed for use in resistant distal colitis include butyrate, cyclosporine and nicotine enemas as well as tacrolimus suppositories and tacrolimus, ecabet sodium, arsenic, lidocaine, rebamipide and Ridogrel^® enemas. Some of these agents have demonstrated impressive results but the majority of the agents have only been assessed in small open-labelled patient cohorts. Further work is thus required with the investigation of promising agents in the context of randomized double-blinded placebo controlled trials. This review aims to highlight those potentially effective therapies in the management of resistant distal colitis and to promote interest in furthering their investigation.

Leukocyte hydrogen peroxide production in a surgical wound in mice. The effects of an amide local anaesthetic

The oxygen metabolism of polymorphonuclear leukocytes (PMN) is of importance in local tissue repair processes. Amide local anaesthetics are commonly used to relieve surgical wound pain. The cellular effects of local anaesthetics in vivo is poorly described in the literature. However, interactions between amide local anaesthetics and the oxygen metabolism of leukocytes have been reported. To extend that knowledge, this paper investigates the influence of lidocaine treatment on the production of hydrogen peroxide (H2O2) by leukocyte oxygen metabolism. A soft tissue chamber model in the mouse was used, allowing measurements of the H2O2 production spontaneously and after phorbol myristate acetate (PMA) addition, from two different leukocyte pools. Exudate leukocytes were generally more reactive to PMA stimulation in comparison to tissue chamber adherent leukocytes. Topically administered lidocaine significantly influenced the number of leukocytes in the wound exudate at 24 h postoperatively. Exudate leukocytes, topically exposed to lidocaine, showed an enhanced H2O2 production in comparison to leukocytes receiving lidocaine systemically. At 6 days, the viability and the H2O2 production differed significantly between the group receiving topically applied lidocaine in comparison to placebo. We conclude that the wound healing process may be effected by topically applied lidocaine, administered in clinical doses, at least via interference with leukocyte oxygen metabolism.

Topical ketamine inhibits albumin extravasation in chemical peritonitis in rats

BACKGROUND

As ketamine has local anaesthetic actions and local anaesthetics are known to have anti-inflammatory effects, ketamine could be expected to be an anti-inflammatory agent. Here we sought to determine whether ketamine is indeed anti-inflammatory in chemical peritonitis induced by HCl in rats.

METHODS

Peritonitis was elicited by applying 0.02 M HCl on the surface of the cecum or appendix and quantified by measuring the extravasation of intravenously injected Evan's Blue bound to albumin extracted from those tissues. Three experimental sets were performed. In the first set, four groups of 10 rats each received: 1%, 2%, and 4% ketamine and 1% lidocaine. In the same animal, before induction of peritonitis one area was topically pre-treated with 0.9% saline (control site) and another area was topically pre-treated with 1%, 2% or 4% ketamine or 1% lidocaine (experimental site). In the second set, two groups of 10 rats each received: 2% ketamine or 1% lidocaine. Ten min after the induction of peritonitis, the control site was topically treated with 0.9% saline, while the experimental site was treated with 2% ketamine or 1% lidocaine. In the third set 20 rats, divided into two groups, were pre-treated either with 2% S(+)ketamine or 2% R(-)ketamine before the induction of peritonitis instead of the previously employed racemic version of the drug.

RESULTS

Treatment of the cecum or appendix areas with ketamine or lidocaine before the induction of peritonitis decreased the extravasation of Evan's Blue-albumin from 5.7 +/- 0.7 micrograms/100 mg tissue to 4.5 +/- 0.8, N.S. with 1% ketamine; from 5.9 +/- 0.8 to 4.1 +/- 0.7, P < 0.01 with 2% ketamine; from 4.8 +/- 0.7 to 3.5 +/- 0.6, P < 0.05 with 4% ketamine and from 5.9 +/- 0.6 to 3.6 +/- 0.8, P < 0.01 with 1% lidocaine. Treatment of the areas of peritonitis with 2% ketamine or 1% lidocaine decreased the extravasation of Evan's Blue-albumin from 5.6 +/- 0.5 micrograms/100 mg tissue to 4.4 +/- 0.6, P < 0.05 and from 6.0 +/- 0.8 to 5.0 +/- 0.7, P < 0.01. Administration of the isomer S(+)ketamine to colonic areas before the induction of peritonitis reduced the extravasation of Evan's Blue-albumin from 6.5 +/- 0.7 micrograms/100 mg tissue to 4.1 +/- 0.6, P < 0.01; while the isomer R(-)ketamine was inactive.

CONCLUSIONS

These results indicate that topically applied ketamine inhibited the development of chemical peritonitis. This action of racemic ketamine was due to the isomer S(+)ketamine.

Inhibitory effects of amide local anaesthetics on stimulus-induced human leukocyte metabolic activation, LTB4 release and IL-1 secretion in vitro

The anti-inflammatory effects of the amide local anaesthetics lidocaine and bupivacaine were evaluated in vitro by examination of the metabolic activation and secretory responses of human polymorphonuclear granulocytes (PMNGs) and mononuclear cells. Pretreatment with lidocaine or bupivacaine had a dose-dependent inhibitory effect on PMNG luminol-amplified chemiluminescence stimulated by bovine serum albumin (BSA)/anti-BSA immune complexes (IC) or by serum-opsonized zymosan (SOZ) particles. Both lidocaine and bupivacaine inhibited the release of the inflammatory mediators leukotriene B4 (LTB4) and interleukin-1 (IL-1) evaluated by radioimmunoassay (RIA). Pretreatment of suspended PMNGs and monocytes with the anaesthetics caused a marked inhibition of LTB4 release when the cells were stimulated with SOZ. In short-term (24 h) cultures of mononuclear cells the addition of lidocaine or bupivacaine reduced, in a dose-dependent manner, the level of IL-1 detected after stimulation with lipopolysaccharide (LPS). In all three assays (chemiluminescence, LTB4 and IL-1 RIA) bupivacaine was found to be more potent than lidocaine. The present results show that amide local anaesthetics have marked suppressive effects on the metabolic activation and secretory functions of leukocytes stimulated by different agonists. Although the detailed mechanisms for these effects are not known, they may explain part of the potent anti-inflammatory actions of local anaesthetics previously described in vivo.

Medical management of severe inflammatory disease of the rectum and distal colon: non-nutritional aspects

Rectal bleeding is the cardinal symptom in patients with inflammation of the rectum, and initial management must be directed at establishing an underlying diagnosis. In many patients in the Western World this will be idiopathic inflammatory bowel disease, although in all cases other causes such as infection must be excluded. Idiopathic proctitis is usually due to either ulcerative colitis or Crohn's disease, and in both conditions corticosteroids, either systemic or topical, provide the mainstay of treatment. The 5-aminosalicylic acid drugs are helpful in both acute and maintenance treatment, again given either systemically or topically, while metronidazole is of value in patients with Crohn's disease. In those with refractory proctitis alternative agents such as azathioprine, immunomodulating drugs and barrier agents may be useful. Severe inflammation of the rectum secondary to pelvic irradiation will also usually respond to topical steroid therapy, although sucralfate enemas may be equally successful; in resistant cases other treatments may be needed. Infective proctitis, when diagnosed, may require treatment with specific antimicrobial agents.

Tripotassium dicitrato bismuthate enemas in the treatment of ulcerative proctitis

Eleven patients with active proctitis or proctosigmoiditis completed one month's treatment with tripotassium dicitrato bismuthate enemas administered at night. Symptoms, sigmoidoscopic appearances, and the histological grade of acute inflammation were assessed at the commencement of therapy and after one month. An overall score of these features showed improvement in 9 of 11 patients, which encourages further investigation of bismuth in controlled trials for patients with inflammatory bowel disease.