Introduction This project involved hip and knee replacement patients at the Royal Bournemouth Hospital. Throughput of surgical cases is determined by the number of operations you can perform each day and the number of beds available for patients following surgery. Modelling using length of stay data indicated that we had enough beds and so we used the Theory of Constraints (TOC) to optimise surgical throughput. The TOC process is outlined below.
Intervention Put simply, the system was required to complete 1350 joint replacements per year through 2 operating theatres. Having established this, we identified the system constraint using TOC methodology. The constraint is the element of the system that prevented additional throughput from occurring. Our analysis revealed that the constraint in our setting was the surgeon. We then designed an operating template that subordinated everything to the constraint. A staggered operating model in which the surgeon moved between two operating theatres to perform 6 hip and knee replacements in succession each day was introduced.
Results The model has been used in over 2000 patients, and 28 different surgeons and 48 anaesthetists have worked within the model. We found that for all surgeons this has improved their productivity, as well as reducing the variability in the time required to complete each individual case. The staggered model and predictable nature of the model has also had benefits to the nursing and rehabilitation staff on the ward. Admissions to theatre and returns from theatre are now equally staggered throughout the day. This smoothing of flow is a central principle of lean and has made the delivery of care much easier on the ward and requires less staff.
Key message The TOC is a useful model for analysing complex systems where one step determines the rate of the process. Within our context the constraint was the surgeon. By subordinating all processes to utilise the surgeons time maximally we optimised surgical throughput.