Summary The aim of this study was to see if antibiotic pastilles could reduce radiation mucositis, pain, dysphagia and weight loss in patients undergoing radical radiotherapy for head and neck cancer. A total of 275 patients with T -T4 tumours entered the study; 136 were allocated to suck four times daily a pastille containing amphotericin, polymyxin and tobramycin. The During treatment, cells in the basal layers of the mucous membranes within the irradiated volume are unable to replace adequately cells lost through inactivation or exfoliation. The resultant mucosal damage may then be exacerbated by colonisation of the affected area by abnormal microbial flora. Mucositis has a number of manifestations that may be seen at different times depending on the volume irradiated, the total dose and the fractionation schedule. Initially, there may be a transient white discolouration, followed by deepening erythema and later a white pseudomembrane which may be patchy or confluent. The most severe manifestation is ulceration of the mucosa.In health, the very diverse oropharyngeal flora contains a marked preponderance of anaerobic bacteria together with a near universal presence of lesser numbers of viridans streptococci and Neisseria species. Irradiation, local tumour and surgery can all interfere with the mucosal defences important for the maintenance of this ecological balance. In consequence, there is frequent overgrowth of organisms rarely seen in health and then only at low concentrations. Overgrowth of yeasts and aerobic Gram-negative bacilli (in particular Enterobacteriaceae, Pseudomonads and Acinetobacter) has attracted particular attention in the context of irradiation mucositis (van Saene and Martin, 1990).There are no established effective measures to prevent or treat mucositis. Standard therapy is to maintain good oral hygiene and prescribe analgesics if necessary. A small study by Spijkervert et al. (1991) described a novel approach to this problem. Lozenges containing polymyxin E, tobramycin and amphotericin B were used to eradicate selectively aerobic Gram-negative bacteria (AGNB) and yeasts from the oropharynx while retaining the normal anaerobic and aerobic flora. This selective decontamination regimen was given to 15 patients with head and neck cancer treated by radiotherapy. An excellent microbiological result was obtained and mucositis was confined to erythema in all patients. By contrast, matched historical controls treated with a placebo or chlorhexidene showed an 80% incidence of more severe mucositis with pseudomembrane formation.The aim of the study was to use a placebo-controlled double-blind trial to test the hypothesis that the more severe forms of irradiation mucositis are associated with abnormal carriage of AGNB and yeasts and that selective reduction of these microbial populations with non-absorbable antibiotics would reduce both the signs and symptoms of mucositis. Materials and methodsPatients receiving potentially curative radiotherapy for T-4 head and neck cancer were entered into th...

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SUJMMARYSaturation diving is an important and widely used technique in the Offshore Oil Industry. During 1974-5 two saturation dives in the North Sea were terminated because of outbreaks of incapacitating otitis externa, and others were disrupted. P8eudomona8 aeruginosa was consistently isolated from the ears of affected divers.Because complex work schedules were threatened seven subsequent dives were subjected to microbiological monitoring and control. Colonization of the ear canal with P. aeruginosa or with other gram-negative bacilli occurred in 39 (67 %) of the 58 divers studied, usually within 7 days of starting the dive. Data obtained by serotyping the isolations ofP. aeruginosa suggested that a single infected diver may be the source of organisms which rapidly spread to his colleagues and throughout the living chambers, that the living chambers may constitute a reservoir of infection during and between dives, and that certain serotypes of P. aeruginosa are more likely than others to colonize the ear canal in the conditions of a saturation dive. The control measures used during the dives were only partially effective, but none of the divers suffered severe pain and all the dives were an operational success.

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The performance of dosage guidelines for starting gentamicin therapy was evaluated prospectively in 50 patients with suspected or proven Gram-negative septicaemia and the results were compared with results from similar group of 50 patients for whom the guidelines were not followed. Peak concentrations were significantly higher when the guidelines were followed (7.2 (+/- 1.9) mg/L vs 5.7 (+/- 1.8) mg/L) but there was no difference in trough concentrations. Fifty-eight per cent of patients had both peak and trough concentrations within the target range (peak > 5 mg/L, trough < 2 mg/L) when doses were decided empirically; this increased to 96% when the guidelines were followed. However, use of the guidelines achieved peaks of > 7 mg/L in only 56% of patients. A revised protocol with higher doses given less frequently was therefore developed and a prospective assessment of its performance indicated that satisfactory concentrations were obtained in 96% of patients.