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
