Feature / When blood turns green

Recycling a patient’s blood rather than using donated units can cut costs, reduce pressure on blood donation targets and benefit patients by shortening their recovery time. Bernard Crotty and Hannah Grainger report.

In the NHS in England and North Wales, donated (allogeneic) blood is collected by a single public sector health organisation, NHS Blood and Transplant – the exclusive supplier to hospitals. Both public and private hospitals are charged per unit of issued blood – £124.21 for 2010/11.

Blood transfusions are needed for two main reasons: to maintain blood volume or haemoglobin (Hb) concentration. These are the oxygen carriers in the blood stream and transfusion would normally be considered appropriate when Hb concentrations fall to 7g/dl in otherwise fit patients and 9g/dl in older patients and those with known cardiovascular disease.

Blood issues to hospitals have been declining since 2000/01 (table 1, below). The overall trend is downwards, with 23% fewer active donors against a fall in issues to hospitals of about 15%. Regular donors are donating more often and the churn of regular donors is rising due to more rigorous selection requirements – any donor who receives a transfusion themselves cannot donate.

There are regular campaigns to recruit and retain new donors and these are becoming more costly. Other developments are also likely to have an impact. A test for Variant Creutzfeldt-Jakob Disease (vCJD) could lead to a reduction in donor numbers.

Better management

A substantial element of the reduction in demand for blood over the past decade is down to better blood management programmes and less invasive surgical procedures, such as keyhole surgery, minimising blood loss. But some commentators believe demand for blood is likely to increase again and evidence in recent years backs this up. A number of explanations have been put forward:

• A steady increase in the number of people aged over 75 (an estimated 35% of all blood is given to people over 75)
• An increase in patients admitted with gastro-intestinal bleeding associated with alcohol use – 223% increase in hospital alcohol related admissions in past 10 years
• Targeted treatments for cancer likely to require more blood transfusions.

On the medical side, primarily the treatment of anaemia relating to cancer, there are few options other than to use allogeneic blood. But in surgery, studies have highlighted the growing impact of blood conservation techniques. Surgical specialties account for a reducing percentage of total blood used (see table 2).

Techniques such as intraoperative cell salvage (ICS) may have played a part in the shift away from surgical usage. In ICS, a machine collects the blood shed during the operation. This is then washed and re-infused back into the patient. Use of the patient’s own blood, unless there are complications, reduces the requirement for an allogeneic transfusion.

A study undertaken in 2003 found that, in operations where an allogeneic transfusion was required, an average of 2.7 units of allogeneic blood was transfused. Using this average, replacing an allogeneic transfusion with salvaged blood in one operation per week would decrease a trust’s blood bill by about £17,500 a year (one unit of blood = £124.21).

Cell salvage has its own costs (see tables 3 and 4). A typical comparison of costs at hospital level using one machine are summarised in tables 3 and 4, above. The payback period is therefore less than 18 months on a relatively low level of activity. This will accelerate as activity increases.

When compared with the number of units of allogeneic blood issued, cell salvage is still not widely adopted in the UK. A Council of Europe study on 1999 activity noted that French and Italian hospitals used recycled blood in 5% of operations, where a transfusion was required. This was against less than 1% in UK hospitals.

More recent surveys in the UK indicate a slight increase up to about 3%, though overall figures still trail the US. Surveys suggest usage in the US is as high as 82% of hospitals (2001), compared with 37% in the UK (2001).

NICE interventional procedure guidance (IPG 144) highlights the potential to decrease length of stay by avoiding an allogeneic blood transfusion. Allogeneic blood is never a perfect match and gradually loses its beneficial contribution as it gets older. Hospitals rarely use blood over 30 days old. Salvaged blood is fresh and maintains its ability to release oxygen into the tissues. This is reduced in allogeneic blood, potentially leading to slower recovery.

Cell salvage cannot replace the allogeneic blood required in a medical setting and is of no benefit to non-surgical treatment of cancer but it can contribute by reducing the blood demanded elsewhere and take pressure off collection targets. Its application is being examined for massive haemorrhages associated with abdominal trauma.

Traditionally allogeneic blood is used in this kind of trauma because of concerns with bowel contamination. The use of filters to remove potential contamination from this surgical setting has been widely discussed in the US and is being developed in Pittsburgh but is not generally used in the UK.

Salvage training

Introducing cell salvage into a hospital calls for adequate staff training – two people for a single machine, say, to cover 10-20 cases a year or 10-12 people for 150 cases a year – and a period of supervised clinical experience and competency assessment. The numbers of staff needing to be trained will depend on the size of the hospital and case load suitable for cell salvage.

Keeping skills current is also important. Other members of the theatre team also need awareness training. A training manual has been developed by the UK Cell Salvage Action Group and the Department of Health website contains other support material to optimise blood conservation.

Once training is complete for elective surgical procedures, the cell salvage operator need not be solely dedicated to the task and can undertake it in addition to other theatre duties – for example, as the anaesthetic assistant.

However, in emergency admissions, it is felt cell salvage may require a dedicated operator to attend to the machine as procedural steps, such as replacing depleted wash solution, need to be carried out more frequently.

The unit costs of blood are largely dictated by NHSBT’s fixed and semi-fixed costs. If there were a guaranteed level of cell salvage, fixed costs could be taken out. The development of patient level costing could help with the uptake of cell salvage. If a hospital’s blood issuing system can interface with the costing system, the savings from cell salvage should become more visible.  It should also enable further investigation of the impact on length of stay.

The future is uncertain. If demand increases, the cost increases for allogeneic blood will be significant. Potential changes to the way allogeneic blood is processed to ensure its safety may also result in increases in cost. An expansion in cell salvage use will allow more certainty of blood supply to support surgical procedures. Cell salvage would also allow a degree of self-sufficiency within a hospital.

A common saying in discussions around blood safety is: ‘The best transfusion is no transfusion’. Given the costs and uncertainty over blood supplies, this seems relevant in a financial context regarding surgery too.

Resources to support cell salvage adoption are at www.transfusionguidelines.org.uk

Cell salvage in the US

The University of Pittsburgh Medical Centre (UPMC) is recognised as a leader in blood avoidance techniques. One of the hospitals within the Western Pennsylvania-wide group, UPMC Shadyside (pictured above), resembles a UK teaching hospital with more than 500 beds and a wide range of medical and surgical specialties.

An NHSBT trust fund-supported visit to the hospital in November 2009 looked specifically at the use of cell salvage machines. The number of operations using cell salvage was divided by the number of available machines and converted to an average per week. This was compared with Morriston Hospital, Swansea, one of the leading proponents of cell salvage in the UK. Morriston’s average of three uses per week compared with UPM’s 3.6.

By avoiding allogeneic blood transfusions, the notional offset of allogeneic blood costs achievable at a trust with Morriston’s level of cell salvage activity would be in the region of £52,000 per annum per machine against forecast costs in year 1 of about £30,000.

When more staff have been trained, this surplus will increase.

UPMC buys its blood from a local supplier and the target blood requirements reflect the high volume of cell salvage usage. More certainty over lower allogeneic blood requirements means, in turn, lower donor recruitment costs. Collaboration in this approach means all parties benefit.

UPMC has invested heavily in information systems and clinician use of blood is regularly compared against standard usage. The blood ordering system flags when allogeneic blood is ordered for a patient with an Hb level of >8.5g/dl. This reminds the clinician that transfusion of allogeneic blood is generally not appropriate in patients with Hbs greater than this level. The clinician has to acknowledge this reminder before the order can go through. With initiatives such as these, UPMC believes its cell salvage utilisation will increase further.