Design of ambulatory surgery facilities

There are several ways of providing ambulatory surgery services.
  • Self contained ambulatory surgery unit - free-standing
  • Office based surgery
  • Self contained ambulatory surgery unit - integrated with main hospital
  • Self contained ambulatory ward - using dedicated theatres in main theatre complex
  • Self contained ambulatory ward - patients incorporated on in-patient theatre lists

Publications promoting ambulatory surgery often concentrate on the efficiency of self contained units and those with their own theatres in particular. Self contained units integrated with the main hospital and self contained day wards using dedicated theatres are the most common types of unit in Europe while in the USA there are a higher proportion of free-standing units. There are advantages and disadvantages with each type of service, however it is important to remember that all variations can be made to work if the patient pathway is clear and the local team are well organised.

Self contained - Free-standing

This type of unit brings advantages of reduced overheads in the USA and this can also be seen with the Independent Treatment Centres in the UK. However there are fewer free-standing units in Europe that are not owned by a main hospital and therefore they have to take a share of all the Trusts overheads. Parking, a major problem for many European hospitals is usually not an issue. However free standing units bring problems that increase with the distance from their main supplier of medical and paramedical manpower. Support services from physiotherapy and laboratory services to Intensive Care and radiology are remote from the unit. Do outpatient clinics take place on site? If not, it means further trips for patients if pre-admission assessment is used. Travelling time of medical staff to and from the unit can be inefficient use of a valuable resource. Patient selection has to be more rigorous and the range of procedures that can be performed is more limited. This can be mitigated if the unit has an overnight stay facility that has medical cover – this will reduce the need to transfer failed day cases to a major facility and so allow more challenging cases to be managed.

Office based surgery

The provision of surgery in a suitable area within the ‘surgeons office’ is popular in some countries. For the surgeon it offers maximal return on investment for their facilities. However the procedures that can be performed and the types of patient that can be selected are limiting factors. There are real concerns about regulation of these facilities and for patient safety.


This type of unit is seen by many as being ideal. Full support services are available and it is easy for patients to visit the unit on the same day as their outpatient clinic visit for preoperative assessment. There is no loss of medical time due to travelling and if the unexpected happens e.g. the patient requiring a laparotomy following uncontrolled haemorrhage during a laparoscopic procedure, then it is easy perform the procedure and admit the patient to an appropriate facility as needed e.g. ward, HDU or even ITU.

Day ward-dedicated theatre(s) in main theatre complex

The distance between the ward area and the main theatre complex is important in this situation. The efficiency of ambulatory surgery depends on the rapid changeover of patients in theatre so that valuable theatre time is not lost. Therefore efficient transfer of patients is important and becomes increasingly difficult with separation of the theatre and ward areas. However the use of patient holding areas close to theatre can address this issue. One consideration often forgotten is the Recovery Room or Post Operative Care Unit experience. The management of first stage recovery of patients is an important aspect of successful ambulatory surgery - staff using their inpatient surgical practice can delay or even prevent day case patient discharge.

Ambulatory ward-no dedicated theatres

Let us be clear this is a very unsatisfactory way of providing day surgery and is not recommended by the IAAS. This setup begins to not only reduce the efficiency of ambulatory surgery but can have serious effects on the quality of service for day patients. Patients admitted to the ambulatory surgery ward may have to wait a long period for their operation if they appear at the end of a list after the major cases. It is inappropriate to fill up the occasional half hour on the end of a list to perform ambulatory surgery as they should be done early on the list to ensure maximal time for recovery. The risk of cancellation is also high if they are following a large case. Putting them on the beginning of the list is more satisfactory but can also lead to the problem of lists over running their allotted time - a problem all too familiar to those with theatre experience. However they are managed the tendency is for the day cases not to receive the degree of attention they require and so the ambulatory surgery success rate is reduced.
We recognise that the above situation may well be unavoidable especially in the beginning. The issues raised can be helped by careful organisation. Having a clear patient pathway so that the patient, the ward nursing staff and the theatre staff all understand that the patient is a day case can help. Having nurses in the Recovery Room in theatres who are educated in ambulatory surgery and form part of a team introducing the service can make a large difference.

Useful documents and websites

Guidelines for Office-Based Anesthesia. 2009 AMERICAN SOCIETY OF ANESTHESIOLOGISTS.(external link)
A shortcut to better services:Day surgery in England and Wales. Published 1990(external link)

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