A STUDY OF METHODS USED FOR DISINFECTION OF ANAESTHETIC EQUIPMENT BETWEEN TWO SURGICAL OPERATIONS AT A LARGE TEACHING HOSPITAL.

A prospective study on the growth of bacteria on certain commonly used anaesthetic equipment was undertaken in a large teaching hospital with a view to assess the effectiveness of disinfection/sterilization procedures. Samples for microbiological assessment were drawn by the worker using standardised procedures and tested in the laboratory by a microbiologist, blinded to the type of sample. Criteria for growth positivity was taken as > 25 colony forming units. A total of 90 observations were taken. 30 each for 'before use', 'after use' and 'after disinfection'. Overall 54.6% of the equipment showed growth "before use" with maximum growth being seen in Suction catheters (66.6%) and Guedal airways (60.0%). On the other hand, the proportion of equipment showing growth "after use" was quite high (84.6%), with suction catheters and endotracheal tubes showing 90.0% growth each. There was significant difference as regards "before" and "after" use growth on Endotracheal tubes, Guedel airways and Face masks (p < 0.05). Analysis of growth "after" disinfection" revealed that the probability of growth remains as high as 70% in suction catheters (95% CI=54% to 86%) and 60% in laryngoscopes (95% CI=43% to 78%). The study revealed gross inadequacies in methods of disinfection being followed at present.