RESUMO
We have done survival analysis of the EKG monitor(from March, 1976 to February, 1993) and anesthetic machine(from February, 1915 to February, 1993) retrospectively in operating room at Severance hospital. Thirty eight EKG monitors and twenty eight anesthetic machines were included. Also EKG monitors were divided into two groups(one group was made in foreign country and another was made in Korea) and its survival function were compared. All statistics were treated with Product-limited estimate of survival function(Kaplan and Meier, 1958) with BMDP 1L. Mean survival time(+/-S.E) of all EKG monitor was 113.61(+/-5.70) months and the EKG made in foreign country was 106.65(+/-8.22) months and made in Korea was 113.35(+/-8.97) months. But there was no statistical differences between two groups. And mean survival time of anesthetic machine was shown to be 189.45(+/-6.09) months. It is advisable to replace aging machine before malfunction and failure to protect patients from mishaps stem from equipment failure. We conclude that life cycle of equipment for proper time to replace the equipment is not underestimated to reduce the accident by aging machine failure.