Gruer, Laurence David

2019-02-15T14:28:39Z

2019-02-15T14:28:39Z

1986

Introduced in 1976, continuous ambulatory peritoneal dialysis (CAPD) is an effective and increasingly popular form of long-term dialysis. Infective peritonitis is its main drawback. This can be caused by a wide variety of micro-organisms, but usually by bacteria from the skin or gut. The commonest and most troublesome causative organism is the coagulase-negative staphylococcus. Although improvements in methods of diagnosis, treatment and prevention were made during the first five years of its use, CAPD continued to be plagued by peritonitis in most centres.

This study was carried out between 1982 and 1984 in the Queen Elizabeth Hospital, Birmingham. A CAPD service began there in 1981 and peritonitis quickly became the main threat to its success. It was soon evident that the methods then in use for the microbiological diagnosis of CAPD peritonitis were inadequate. A simple method of culture was developed which greatly increased the chances of a positive microbiological diagnosis. This method became the cornerstone of a more effective and economical laboratory service to the CAPD progranme.

The antibiotic sensitivities of organisms causing CAPD peritonitis were studied with the aim of establishing a more effective initial treatment policy. Vancomycin was found to be the most consistently active of the antibiotics tested against Gram positive isolates in general and the coagulase-negative staphylococcus in particular. Aminoglycosides were the most consistently active against Gram negative isolates. A trial of intra-peritoneal vancomycin and tobramycin showed that this combination was much more effective in the initial treatment of CAPD peritonitis than cefuroxime, previously the antibiotic of first choice. However, potentially ototoxic levels of tobramycin were encountered.

With the aim of making initial treatment both simpler and safer, a modified protocol involving once-daily intra-peritoneal vancomycin and gentamicin was developed. One hundred episodes of CAPD peritonitis were treated, of which 88 were cured without recourse to other antibiotics. This study showed for the first time that most episodes of CAPD peritonitis could be safely treated at home using intra-peritoneal antibiotics self-administered oncedaily. The problem of aminoglycoside toxicity was not solved, however.

Many episodes of CAPD peritonitis follow contamination of the administration set with organisms on the patient's hands. Contamination usually occurs during the dialysate exchange procedure. We studied how effectively bacteria were removed from the patients' hands by washing with povidone iodine detergent or 70% ethyl alcohol. Surprisingly, povidone iodine was often found to be counter-productive. Ethyl alcohol was much more effective and convenient.

Despite improvements in the diagnosis and treatment of CAPD peritonitis, its incidence at the Queen Elizabeth Hospital has recently increased. This may in part be due to a steady decline in the amount of time staff can devote to training and supervising individual patients: staffing of the programme has failed to keep pace with the rapid rise in patient numbers. The thesis ends with a review of a variety of recently developed techniques and strategies which aim to prevent CAPD peritonitis.

http://hdl.handle.net/1842/34581

The University of Edinburgh

Annexe Thesis Digitisation Project 2019 Block 22

Already catalogued

The diagnosis, treatment and prevention of CAPD peritonitis

Thesis or Dissertation

Doctoral

MD Doctor of Medicine