3D imaging at microscopic levels

maging system in order to improve the visualisation of patient data for doctors, surgeons, pathologists and research scientists.

Image: http://theberkshireedge.com

The Imaris 3D system incorporates features that allow time-based visualisation of images, the creation of 3D or multi-channel images, or the production of animation movies. One feature, for instance, can be used to monitor temporal changes in biological systems. The system also seeks out filaments such as neurons, microtubules or blood vessels and retains and calculates topological information for the user.

The Imaris system can also be used in conjunction with a stereomicroscopes or endoscopes either to get a real-time and deeper view of patient tissue or as a training tool for future surgeons.


Cleaner and warmer patients

Kimberly-Clarke has announced the launch of its Patient Warming System that improves patient outcomes and reduces healthcare-associated infections across a range of surgical procedures. The new system allows anaesthetists and surgeons to precisely manage patient temperatures during complex, lengthy surgeries.

The system is a stand alone unit that circulates water at a precise temperature through disposable hydrogel pads placed directly on a patient to deliver an even and all-body warming process. When the patient’s ideal temperature is reached, the system adjusts the water temperature to maintain the preset target. The unit can either be set at automatic or customised depending on the requirements of each procedure.

Through the direct application of its novel hydrogel warming pad, the company says that users of the patient warming system would only have to cover 20% of a patient’s body and manage patient temperature effectively.


Ophthalmology: Line of sight

Douglas Clarkson looks at the use of selective laser trabeculoplasty (SLT) and how it compares with other forms of treatment for the effective management of glaucoma.

Image: wikipedia.org

The pressure within the eye is a fine balance between values that are sufficiently high to maintain the rigidity of the eye but not so high that it results in glaucoma, a condition that can cause irreversible damage to the nerve fibre layer and associated structures in the eye. In its normal state the inflow of clear fluid in the eye, the aqueous humour, is balanced by the outflow of fluid through the trabecular meshwork. Where the effectiveness of this meshwork to release fluid is impaired, then the pressure in the eye increases’ a condition known as primary open angle glaucoma. Currently more than half a million people in the UK have glaucoma of various types and more than 200,000 people have lost their sight through this condition.

Conventional surgery has always included a surgical procedure called trabeculotomy to open up the trabecular meshwork where other interventions including topical medication have failed to reduce pressure levels. During the 1970s the technique of using lasers to try to open up the meshwork and hence reduce the intraocular pressure (IOP) was developed using argon lasers’ a technique called argon laser trabeculoplasty (ALT). At the same time a range of specific laser types including krypton, continuous Nd:YAG and diode lasers were also investigated.

The mode of interaction of the argon laser with the trabecular meshwork and adjacent tissue can result in coagulative damage to associated structures as a consequence of the relatively high levels of energy delivered during the treatment process. The specific tissues within the trabecular meshwork are a mixture of pigmented and nonpigmented cells and with the argon treatment producing nonselective cell damage.

It was subsequently determined by Anderson and Parish1, however, that optical radiation could be tailored to selectively target pigmented tissue structures. This led Latina and Park2to develop a selective laser trabeculoplasty (SLT) technique where effects at the cellular level could be triggered using pulses of shorter duration and lower energy, with the benefit of much reduced collateral damage.

Selective laser trabeculoplasty has centred on the use of a wavelength of 532nm (green light) at a pulse duration of three nanoseconds. The beam diameter used is 400 microns. A mechanism known as frequency doubling is used to convert optical radiation at 1064nm produced by a Nd:YAG laser to the 532nm wavelength. In the delivery technique a special lens is used to reflect light through the pupil to target the trabecular meshwork above the rim of the iris. Most treatments involve a 180 nasal section of the trabecular meshwork, though other studies have involved both 90 and 360 sections. Current theory suggests that a key factor in effectiveness of the SLT technique is the release of macrophages within treated cells which results in the restoration of function of the meshwork.

Clinical studies

There have been a range of clinical studies comparing the effectiveness of different treatments for glaucoma, including argon laser trabeculoplasty, selective laser trabeculoplasty and a range of conventional topical medications. A comparative study carried out by Martinez-de-la-Casa3, for example, looked at both the SLT and the ALT techniques (see table). Similar to other studies, it found a greater mean percentage decrease in IOP six months after treatment with SLT treatment. There is a trend for the decrease of IOP to continue beyond the six-month post-treatment period as if the metabolism of the trabecular meshwork continues to recover some time after initial treatment.

SLT appears to be a low energy technique for the restoration of the function of the trabecular meshwork in a majority of patients presenting with raised levels of intraocular pressure.

The study by Martinez-de-la-Casa is novel in the sense that it determines an objective measurement of inflammation as a result of treatment  determined by the level of light scatter within the aqueous humour. The SLT technique was noted to also give rise to a smaller IOP spike’s after treatment compared with ALT.

Usually the level of post-treatment IOP elevation with SLT is not significant. However, a review by Harasymowycz4 of patients presenting with IOP elevation after SLT indicates that patients may be at higher risk of this complication in cases where the trabecular meshwork is deeply pigmented, previous ALT procedures have been undertaken or multiple topical medications have been applied.

One of the few studies to compare longer-term outcomes was undertaken by Juzych5. Patients receiving SLT (41 eyes) and ALT (154 eyes) were compared over a five-year period. Success was defined using two separate criteria. The first was a decrease in intraocular pressure of 3mm Hg or more with no additional medications, laser or glaucoma surgery. The second was the same but an IOP reduction of 20% or more was required for success. For the first criterion, 31% of patients treated by SLT were considered a success compared with 21% for those who had had ALT. For the second, the comparable figures were 31% with SLT and 13% with ALT. However, overall the long-term success rate between the two groups was not significantly different. But the authors noted that in the longer term many of the patients treated with ALT and SLT required further medical or surgical interventions to manage the levels of intraocular pressure.

In some ways, the conclusions drawn by Juzych exercise caution regarding the effectiveness of SLT in IOP management. The indication, however, that a single SLT treatment can manage IOP levels over a five-year period for a significant number of patients is not without an obvious health economic benefit. The topical application of drugs, is not without identified side effect’s  although the latest types of anti-glaucoma medication, such as prostaglandin analogues, are once daily and produce fewer side effects than, for example, beta-blockers. It is a common feature, however, of clinical studies into glaucoma medication that a significant percentage of patients may discontinue their medication. In addition, patients may not respond favourably to topical drug management.

A useful current review of SLT studies was recently published in Opththalmology Clinical North America by Latina6. To date in the UK, the National Institute of Health and Clinical Excellence (NICE) does not appear to be considering the evaluation of SLT technology. The only current work in hand in connection with glaucoma is evaluation of lerdelimumab  one of a series human anti-TGF beta 2 antibodies, with the potential to prevent post-operative scarring in patients undergoing conventional surgical trabulectomy. In the US, where physicians are paid at specific rates for delivering SLT treatments, around 1000 laser SLT systems have been installed and are in regular use. In addition, the SLT mode is actively promoted as an upgrade path to an existing Nd:YAG system.

Market availability

Current offerings in the marketplace include the Selecta II Glaucoma Laser System from Lumenis with the Selecta Duet also providing conventional Nd:YAG capsulotomy treatments. The Solo model (SLT only) and Tango model (SLT with Nd:YAG) are also available from Laserex.

Clinical studies show the value of SLT as an intervention to lower intraocular pressure, although an appropriate level of follow-up is required for effective longer-term patient management which may require additional interventions. As the management of glaucoma has a significant impact on the health economy, and current levels of population screening are not sufficient to detect the disease in its early stages, there are also sound economic arguments to adopt SLT as the primary means for lowering intraocular pressure. Choosing the appropriate technique to manage treatment can help to prevent vision loss, benefiting the patient and improving their quality of life.


Procurement consultant: Dr Colin Connolly on PbR

The move to standardise clinical costs across the health service through Payment by Results is likely to run into problems because of continuing inaccuracies in costing clinical activities Dr Colin Connolly.

Payment by Results (PbR) is a natural progression of a whole series of reforms in both the funding and related clinical activity levels in the NHS health delivery system. Integral to the reforms is the dictum that money follows patient’s.

It is a philosophy that was first embedded in the NHS when allocations were switched from being made directly to NHS hospital trusts on an historical cost plus inflation basis through to channelling revenues through primary care trusts (PCTs). NHS hospitals in the secondary care sector now receive their income from the PCTs buying clinical services using the so-called clinical contract system.

The problems in delivering this admirable philosophy is that both the measurement of clinical activity and its associated costs have been and are still subject to wide errors. Problems are numerous, not least of which is that costing anything with the accounting system currently in use is at the very least difficult and probably impossible with any accuracy. The current system is both loaded with overheads and clinically nonspecific.

The study group attempting to cost specific clinical activity and its associated costs in diagnostic related groups (DRGs) or health resource groups (HRGs), has been engaged in its Herculean labours for fifteen years at least. Efficiency of frontline clinical services, supporting clinical diagnostic services as well as supply and hotel services on which the NHS relies have been subject in this period to continuous revolution sweating the asset’s, efficiency savings and Samuel Smiles initiatives, value for money, market testing, outsourcing, PFI/PPP and resource allocation to PCTs to buy hospital services via clinical contracts. This is in addition to the ongoing reorganisation of NHS bureaucracy.

The new systems to be imposed in 2006 under the stirring motto of PbR assumes that the problems of costing clinical activity have been largely solved. Allegedly, the inaccuracies are small enough at 2% to be addressed within the financial flexibility available to NHS trusts as they are reformed as stand alone NHS foundation trusts.

The assumptions made to support the introduction of PbR are based on models of standardisation for costing clinical procedures. Everyone will be required to have the same costs for the same procedures. This will pervade the whole of the internal management of clinical and nonclinical departments in trusts of whatever type, creating consequences for the supply costs of drugs, clinical and nonclinical disposables and equipment of all kinds which account for 20-25% of the total costs of clinical and diagnostic procedures.

The impact of the cost standardisation models adopted will be significant throughout the health services delivery system but particularly on clinical freedom and choice and the costs of supply. As far as supply is concerned, the Henry Ford philosophy that you can have any colour as long as it’s black seems appropriate. No wonder both the activities of the NHS Purchasing and Supply Agency (PASA) and the NHS Logistics Authority are currently being market tested.

Cost standardisation initiatives will also impact on the specifications for market testing of both NHS Logistics and PASA, since the focus will be on the supply of consumables and disposables. The models for PbR for NHS trusts include the cost of supply of consumables and disposables as overheads on the standard patient cost models adopted. Because of the volume of cost involved in supplies, it is the standard cost profile of supply that will inevitably cause supply cost to be used as a regulator of NHS trust cash flows.

The use of supplies as a cost regulator for the NHS in delivering its cash flow has a long history and it is this that has always created volatility in the associated volume of supply.

The need to match the cost of supply to the standard models of care to support the implemention of PbR will inevitably drive the supply cost profile down by far more than the cost errors of 2% allowed as a risk in the PbR accounting systems adopted.

Further still, as NHS trusts and PCTs realise the risk to cash flows, there will be growing pressure on one of the few costs that can be cut in the short term for which the cash limit needs to be delivered and for accounts to be balanced.

Finally. since the cost of supply has always been used as a cost saving in delivering trust cash limits at the end of every financial year, it is inevitable that suppliers will come under cash flow pressures of their own from the variation in supply delivery demanded. PASA and NHS Logistics or the new purchasing consortium will need to take into account the variation in supply delivery volumes.

But one issue that is not figuring loudly in the new initiative is the cost of quality, which will involve the freedom to use an intensity of diagnostics applied to patients which currently varies enormously within the NHS. The effects of the uncertainties created by PbR will emerge as the initiative is applied but in my view will lead to major risks to service delivery. My comment on yet another new initiative is: Forgive them for they know not what they do.


Clinical advisor: Anita Rush on bariatric care

In the August issue, HES questioned if trusts were procuring appropriate bariatric equipment. Providing appropriate care for these patients is complex and can only be done well by taking a holistic approach to patient care.  Anita Rush.

Bariatric management is a new concept in service and equipment provision. It started for me some years ago when I was tasked to provide equipment and home care for a bariatric patient in their domestic environment. The lessons I learned from that experience and the knowledge I gained from doing a Masters degree in Health Ergonomics enabled me to recognise that managing bariatric patients was full of challenge’s  including financial and human resources, equipment design, knowledge and training and environmental constraints.

Bariatrics is not just about providing the right equipment. It is about placing the bariatric patient at the centre  thinking out of the box and taking a holistic approach to patient care. The fact that most bariatric patients cannot tolerate lying down due to breathing impairment, may have skin problems, suffer from lack of self esteem or have other related medical problems means that sound clinical assessments and robust policies and procedures need to be in place to ensure safe systems of work.

A good guide is to base the procurement of bariatric equipment on 70% clinical need and 30% financial considerations. The selection of equipment should be done in a systematic way and form part of the risk assessment process. Equipment reviews should not only consider the needs of the bariatric patient but also include local and national statistical data, prevalence, adverse incidents and near misses.

In addition, the equipment must be fit for purpose. If the caregiver using the equipment cannot position themselves in a safe and comfortable posture to assist the patient to move, then there is an increased risk that the caregiver will suffer a musculoskeletal injury. But selecting appropriate equipment will reduce the inherent risks associated with handling bariatric patients and ensure the well being of both patients and staff.

It is essential when assessing and designing equipment for bariatric patients that their body dynamics (height and body type), mobility and weight (most bariatric patients will underestimate their weight) are taken into account. For example, when looking at beds the weight of the mattress, its height, and the weight of the patient’s spouse (if applicable) need to be considered in relation to the weight and height of the patient. In addition, in some cases the back of the bed will need to regress to accommodate the bulbous gluteal region.

But it is not only the patient with whom the equipment needs to be matched up. Different types of equipment also need to be compatible with each other. For example, if a hoist cannot lift high enough to get a patient easily on or off a bed, there is a risk of pressure damage to the patient due to shearing and to the nurse of musculoskeletal disorders as they drag the patient over the bed. If the patient is mobile then the bed needs to go low enough for them to lift their legs into bed  it’s well known that bariatric patients often do not go to bed as they cannot raise their legs high enough to get into bed.

When a bariatric patient is placed in a ward, they can take up to two bays, so it is important to assess whether there is enough space to accommodate them, whether the lift will be able to take the combined weight of the equipment and the patient and if the floor will also take the weight, particularly if on upper floors. There also needs to be enough room to enable the use and manoeuvrability of equipment and to accommodate at least four carers’ ideally at least 1.5 metres between the walls of the room and the equipment. The floor space should also be big enough for other equipment, such as mobile or gantry hoists, glide-about commodes, wheelchairs, stretchers (in acute environments) and the fallen patient.

So, how can procurement specialists, manufacturers, professionals and end users working within the health and social care environment contribute to providing the right environment and appropriate equipment provision to enhance the bariatric person’s self esteem and ensure that staff are competent in using the equipment supplied?

One thing that is essential is proper training. Knowing how to use the equipment is paramount to the safety of both the patient and the professionals using the equipment. Efficient training in conjunction with manufacturers should be competence-based and part of the procurement package.

I also think that bespoke equipment will be required to meet individual needs. Procurement specialists, manufacturers, end users and health professionals need to work alongside organisations and equipment designers to reduce the inherent risks associated with managing bariatric patients, influencing equipment and environmental design for current and future users.

Good work is being done by many manufacturers who over the last few years have responded well to the needs of bariatric patients, designing equipment using a systematic framework of data collection from end users and professionals that has enabled their design to be reviewed and improved. But we have a long way to go. It is time to think more laterally, to take a real look at today’s environment, and design equipment that is fit for the purpose  for appropriate and safe bariatric care.