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The new NICE guidelines on pre-operative assessment (POA) outline which tests are required in order to decide whether a patient is fit for surgery. To decide which tests are needed, the guidelines state that a patient's 'ASA' scores should be taken into account. ASA scores are determined by the American Society of Anestheologists' Physical Status Classification System, and they can be used to quantify a patient’s “fitness to undergo an anaesthetic” (NICE 2016).
A patient's ASA score also determines which type of pre-operative assessment (POA) they will require before their operation. POAs may take place over the phone or face to face, with either a consultant or a nurse. At the moment, some 16% of all patients do not require any assessment prior to receiving surgery.
Because of the NICE guidelines, a patient's ASA score is critical to decide which assessments are needed to determine their fitness for surgery. However, this score is usually not known when tests and assessments are initiated: instead it is informed by the outcomes of those tests. There are concerns that testing might be ordered unnecessarily which would consume resources and cause delays to patients being declaired 'fit for surgery'.
Anaesthetists at Royal Cornwall Hospitals NHS Trust (RCHT) want to know how implementing the new NICE guidelines will affect the time taken for patients to be declared fit for surgery, and the numbers that require a POA.
They suggest that knowing ASA scores in advance, instead of having to contact GPs to get results or perform new tests, would help to streamline patients and identify the right type of pre-operative assessment for each one. However, this would require considerable financial investment in IT systems and software to allow access to the scores, so evidence is needed that knowing the scores would make the POA process more efficient.
Dedicated decision support during triage, such as applications or questionnaires, could help to appropriately assess ASA scores prior to the POA process, which would then reduce resource utilisation and unnecessary testing.
The two main project aims are:
The underlying processes involved in pre-operative assessments have been initially mapped during an interdisciplinary stakeholder meeting at RCHT. This allows the PenCHORD team an insight into the processes and the dependencies between stages. The information team at RCHT are currently gathering anonymous historical data which PenCHORD will use to parameterise the simulation model.
Screen capture of the simulation model.
PenCHORD are working with clinicians to develop a demonstrator model which will be further tailored to the needs of individual departments at RCHT. The prototype will facilitate engagement with the modelling process and allow the model to capture underlying processes as accurately as possible.
In order to implement the new NICE guidelines a new IT system is required at RCHT to capture patients' ASA scores much earlier in the POA pathway. It is anticipated that the model developed by this project will help describe the potential benefit of the new NICE guidelines in a way which supports the investment required.
Mapping the POA pathway to develop the simulation model has already helped increase clarity about the current POA services offered. In addition, collecting the data to populate the simulation model has highlighted potential improvements to the system structure.
This study could also help assess the potential added value of decision support at triage, i.e. whether dedicated applications for computers and smartphones, or dedicated questionnaires could help streamline the triage processes.
If such decision support was then implemented by RCHT, the anticipated changes in waiting times for 'fit for surgery' decisions that the simulation study predicted could be compared to actual figures.
Royal Cornwall Hospitals NHS Trust
Catherine Cade - Project Manager
Barrie Phypers - Lead Consultant for Pre-operative Assessment
Claire Richards - Lead Nurse for Pre-operative Assessment