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Investigating the process quality there must first be formed modules, and then their typical and ideal outputs will be discussed. Then 'the blackboxes will be opened' and each module will be analysed and newly designed.
Process Modules And Their Specific GoalsThe process can be separated into four phases with respect to the major task of each phase: auto-selection, presurgical selection, surgery and postsurgical treatment. A patient undergoing Refractive Surgery should proceed through all these phases. However, at the borders of each module there is a big loss of (potential) patients. The reasons of dropping out of the scheme differ in each patient. Nevertheless there are similarities in the reasons why patients choose to drop out of the process at the various stages. The aim of process analysis is to become aware of these motivations and to improve the process so that these losses only occur when it is to the benefit of the patient. In the short-sighted view of the clinic, the aim would be to persuade as many patients as possible to undergo surgery to produce higher short term profits. However, many of these 'persuaded' patients would be disappointed after surgery and not recommend the surgery, even less the institution to others. In the long run the interests of the clinic and the patients will rather be the same. The task of the clinic will be to select as many patients for surgery who will be happy with the results after surgery and convince only these patients to undergo surgery. Therefore the four phases need to be structured consciously to induce and control best patient selection. Analysing the borders of each phase in a top down approach will reveal the actual status of uncontrolled patient selection. Requirements for a controlled conscious patient selection process can be developed. This will be done by defining general policies and classes of outputs in each phase. In a next step the blackboxes will be opened and each phase will be analysed more closely. A process model for all phases will be developed to fulfil the built-in requirements of each phase. The phase of presurgical selection will be the most in focus, as it strongly defines the possible outcome of surgery and patients attitude for undergoing surgery.
Auto-SelectionBefore the patient wants an appointment asking for surgery he has already selected himself from many other emmetropic patients who are not interested in surgery. This individual choice is most fundamental and should never be forced. Disappointment and complaints would a rise, if patients are operated onagainst their will or due to false information. The patient therefore will make an appointment according to his general attitude towards surgery, his personal situation and the given information, as shown in the diagram. His general attitude will be influenced most by the family's education, a country's culture and the zeitgeist. His personal situation is characterised by many variables, such as age, profession and personal environment. The information he has received about Refractive Surgery is the only variable which can be controlled in some way. Information about Refractive Surgery can range from the results of operated friends to mass media and official brochures from ophthalmologists' societies. In the long run, this information will correlate strongly to the satisfaction and results of former patients.
| Figure 28: Auto-Selection of Patient |
Presurgical SelectionThe next phase is the presurgical selection, this is to say when the patient makes an appointment to see whether he is suitable for surgery. It is in this phase that he comes into contact with the clinical institution for the first time. The aim of this phase should be to match the technical possibilities of surgery with the patient's individual requirements. Surgery will be a good choice when the technical best matched outcome will be above the individual's expectations. Each patient will have his own personal expectations which will result from his situation. In accordance to Meyer this will be the sum of all the provable and the subjectively true judged beneficial expectations [Chapter 3]. An integrated selection process will only produce three types of patients. Patients who can not undergo surgery for medical reasons, patients who should not undergo surgery because of a frustrating difference between their expectations and the expected outcome, and convinced patients with best matched individual surgical parameters. The three outputs in figure 30 show this ideal situation.
| Figure 29: Common Presurgical Selection | However, today's common presurgical selection phase is focused only on the medical point of view. The patient is passed through all the necessary examinations. After this time consuming "torture" he will be told whether he can undergo surgery or not. The technical parameters of the surgery are usually not matched with the personal situation of the patient. [2] In taking the decision of undergoing surgery the patient does not get help or sufficient information as to whether the expected outcome will meet his expectations of surgery. Many patients will be somewhat indifferent to surgery because they lack information. Moreover, the lack of information will provoke that any experienced observation during the presurgical examination will hold as a reference information to the patient. Again, the fact that any eye surgery is unpleasant will support any unpleasant experience and finally hold off many indifferent patients from surgery. Excess time spent waiting will frustrate any patient's attitude and give more opportunity for making unpleasant observations. On the other hand, an ophthalmologist might use his authority to talk the patients over to surgery. Depending on the mood of the patient he might sustain this manipulation. Patients are thus persuaded, are more likely to be disappointed than well informed patients. Today's patient selection is therefore far from the achievable best patient selection. The following picture demonstrates the common continuum of patients after presurgical selection. The actual amount of patients undergoing surgery might be similar to a well controlled selection but with much less satisfaction.
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Figure 30: Best Presurgical Selection |
SurgeryThe surgery module can be analysed and designed in two complementing ways. Firstly, in optimising the process as to how the patient passes through the different stations. Secondly, an analysis of the detailed surgery and its recommendations for the best handling of the surgery. The aims of the former should be to shorten the total stay of the patient and to improve contact with and integration of the patient. The latter will take advantage of the long Barraquer experience in handling this surgery. Moreover, the development of organisational hints to allow statistical quality improvement will be under focus.
PostsurgeryThe postsurgical module can be divided in two different phases: small ophthalmic control the day after surgery and complete control one week after surgery. The latter should be repeated three, six and twelve months after surgery. Depending on the culture, many patients will not turn up for these controls if they have to pay for it. The costs of post control should therefore be included in the price of surgery. The process of examination will be similar to the presurgical selection process. Patients should also be asked systematically about their subjective sensations. When mixing operated patients and potential candidates in controls, one should be aware of the interactivity between the different groups. Any unsatisfied patient will easily affect the potential candidate's opinion. A 24 hour accident service should be provided in case there are problems with the flap's interface. If post control is done by a different institute, adequate payment rules should be arranged before surgery to guarantee best service. If post control is decentralised frequently, proper wide area feedback channels should be settled for quality control.
Process Analysis and DesignThe modules will now be investigated in detail and as a consequence new process modules will be designed. The auto selection phase will not be further detailed, as aspects of this phase have already been discussed in 6.1.1. The notation which will be used is common in a discrete simulation of processes. The advantage of this notation is that it is easy to understand and the basic actions of the process carrier, e.g. patient, is visible. Given the fact that this paper is addressed to ophthalmologists and the fact that the complexity does not require a more complicated notation for a new organisational design should strengthen this decision. However, for the implementation of an information system of new design, a different notation for modelling will be necessary. This can be an integrated tool as the ARIS-Modeler or a paper based on single sight notation like for the ERM notation. See [Kus94] for the selection of an adequate notation when planning an information system. The notation in this paper uses different symbols for static and dynamic elements. The two dynamic elements are the process carrier and the transportation unit. The process carrier is symbolised by an ellipse with a black top as shown in (fig.32). The history of the patient could be defined as a second process carrier. However, where ever the patient will be examined the history must be at place. Additional modelling of the history would be somewhat redundant. The second dynamic element, transportation, is represented by a rectangular symbol with a cut edge. Although the patient will move himself he still must be co-ordinated and organised when changing between consulting rooms. The history needs to be co-ordinated and physically transported between consultation rooms. The static elements are the stations (consultation rooms), the repositories (waiting rooms) and the paths (floors) which the patient has to pass through. The stations are represented as rectangular symbols, repositories as a half-moon and the paths as arrows. When simulating a production process different kinds of rules exist referring to access, capacity and time spent at each station. Many of these rules result from the passive nature of the process carrier and the transformation of different process carriers. For our purposes it will be sufficient to concentrate on the basic structure of the process, on time variables and some access rules.
PresurgicalAfter auto selection the interested patient will make an appointment with the clinic of his choice. The kind of telephone manner the patient receives will give an immediate image of the institution and strongly influence the patient's attitude. Moreover, this situation could be used to get the first information about the patient. Usually the conversation is limited to finding the first free spot on the calendar which suits the patient. Instead, the patient could be asked why he wants to consult an ophthalmologist. In accordance to this information the patient could be immediatly categorised. New patients applying for Refractive Surgery could be united to certain days when all resources could be 'lined up' for the benefit of the patient, and further information such as age could be collected. On the other hand, the patient could be informed about certain circumstances. For instance, that he should not wear contact lenses for two weeks before consultation and that he should bring some sun glasses, as his eyes will be sensitive to light for two hours after the examination. It should be mentioned that receptionists will need some special training for this conversation. Depending on the amount of phone calls, the published phone numbers could already guide the patients towards specialised receptionists to improve the conversation and to minimise stressing phone call co-ordination. The following picture summarises the discussed situation of answering to telephone calls, showing the traditional way on the left and the newly designed approach on the right.
| Figure 31: Calling for an Appointment | On the day the patient enters the clinical institution, he will first come into contact with the receptionist. In most institutions he will than start a long journey passing through various medical examinations. He might be lucky, and be able to take all the examinations on one day, however, often he is not able to do this. Maybe, he did not stop using contact lenses, or maybe he was not informed how much time examinations will take, or maybe the organisation does not allow for quick examination. The following picture shows the long journey the patient has to take. The sequence is typical, but some examinations might follow a different sequence. Before the patient is examined by an ophthalmologist, he will pass a basic vision examination so that the ophthalmologist gets a quick overview, without wasting his time for time consuming measurements with each patient. The ophthalmologist will than look for general contraindications before the patient undergoes more detailed examinations. The following two examinations are of a similar nature. They only take a few minutes each and the amount of time for each patient examination is almost the same. However, due to historical development they might be located in different rooms and even on different floors. In reality a patient might spend more than an hour undergoing these two exams. In the worst scenario he might need to leave the clinic because the person in charge is not available. Even the institution itself has to spend more staff and resourses in co-ordinating the patient and his history, than in actually doing the exams. Nowadays these examinations can easily be done by anyone with half an hour's initial training. Locating the equipment in one room with additional direct access to the optometric consulting room would allow for efficient and quick consultation. Depending on the amount of patients, the exams could be done by one or two optometrists. In any case the history can be passed on in handshake manner without additional staff, possible equivocations or time delays. Usually the FIFO (first in/first out) principle will be used. If patients of different consultation lines need to pass the same examination different rules might be set up in accordance to the actual amount of patients. The patient will then be prepared with drops for undergoing cycoplexic vision examination. Myopic patients must also undergo a retinal check to minimise the risk of possible retinal surgery with a recently operated cornea after the LASIK surgery. The latter examinations require drops and can only be done at the end of all examinations. A final consultation with the specialised ophthalmologhist in Refractive Surgery will end the process. He will check the examination results and tell the patient whether he will be a good patient for surgery. The total time needed for the examinations is about an hour (57min) on average. However, the patient will most probably spend the whole day in the institution; spending about 7 hours in waiting, looking for his way around the institution, asking secretaries, disrupting other consultations and making phone calls to cancelling his other important appointments. During all that wasted time the patient will be constantly observing what is happening around him. His positive attitude torwards surgery might decrease every minute. Speaking in the words of Meyer, most institutions do everything to decrease the needed integration of the patient. The contact potentials are close to zero and the consumed process quality is below any degree of satisfaction.
| Figure 32: Typical Tayloristic Organisation of Presurgical Examination | Of course, 57min is somewhat unrealistic. However, the waiting time should not exceed the time of actual consultation. A two hour stay for undergoing all the examinations is possible, even after increasing the quality of the examinations. Referring to the discussion in chapter 4 about different types of organisations in services, a group/line organisation seems like a must for a customer orientated approach. A splitt tayloristic organisation in ambulant medical service only makes sense when the variety of patients is high and the costs of having unused resources are of significance. For our situation, in an institution which is highly specialised in Refractive Surgery, the organisation and the management of patients needs to be designed for these requirements. The universal workshop style may allow a flexible response to any kind of patient and for any kind of examination at any day but to the cost of slow and bureaucratic management. A group/line organisation can be flexible enough to respond to the patients by allowing a much quicker and better service. The following sketch will be an approach to replace the old tayloristic organisation.
| Figure 33 : Best Selection Process in Group/line Organisation | The sequence of exams has not been changed nor the expensive time the ophthalmologist spends with the patients. However, the disruption of the patient flow has been cut from eight to only two waiting rooms. If the patient has to wait 20 minutes in each waiting room he would have undergone all examinations in two hours! There are actually only two major changes which count for this six hours time reduction. First, all corneal measurements are done at one station so keratography, topography and the cycoplexic vision examination are done in one room. Staff would be organised according to the amount of patients as mentioned earlier. Besides, the time saving aspect for the patient, the integration of this work will make co-ordination much easier. The history will be passed on without additional transportation or co-ordination as everything is done in line and at the same location and thios will reduce the risk of losing the histories. If the mentioned optometric station is even located close to the ophthalmologist the contact potentials of the clinic grow even more. Topography and keratography should be in line but should be slightly separated from manual vision examination to allow flexibility for other patient types to 'intersect' the station. Second, the reception and the first optometric measurement have been integrated to one station. The reception should not be seen as an anonymous information desk. Instead it is moment of the truth, where the patient gets his first impression of the clinic. Moreover, to guarantee best co-ordination the reception must get somewhat involved in the problems of the patient. Instead of having many untrained staff, patient contact and integration would be improved by fewer but trained staff. A managing crew of a well experienced receptionists directly working together with an optometrist could give the patient the best guide to the institution. New patients would automatically receive the first vision examination. Patients applying for Refractive Surgery would be informed personally, and be equipped with a hand-out to prepare them for their final consultation with the refractive specialist. This will ensure best information exchange and induce efficient "to the point" consultations. As the expectations of the patient and the expected outcome of surgery are matched up, there will be only two groups of patients at the end of the selection process: good candidates undergoing surgery and candidates not undergoing surgery. The indifferent patient is omitted.
Surgery
Process of the PatientFigure 34 follows the approach that the patient is the process carrier. The patient starts the process of surgery before entering the actual operating theatre. When he turns up, he begins at the reception, where the scheduled surgery is confirmed. If there are any delays can wait now, still being comfortable in his clothes. He then has to undergo the presurgical preparation, which mainly consists of changing his clothes for surgery. He will be given some kind of tranquilliser, if he seems very nervous to ensure sufficient integration. Delays above 15 minutes should not occur at this stage, the ability of integration could suffer due to the missing respect of the patient. After surgery he needs to recover about two hours, during this time a first control by the surgeon is taking place. He then will go home by taxi or be taken home by friends.
| Figure 34: Process of Surgery | It may be surprising that most steps are in one box, even though the steps take place at different locations. However, all programmed patients for LASIK surgery have to follow this path. Taking out the buffer times and waiting rooms simplify this path. The history of the patient needs to be present only in the operating theatre. It makes things easier to have all histories of the expected surgeries at the reception to avoid delays caused by having to locate missing histories. After the patient has checked in the history should be brought to the surgical room. The optometrist handling the programming of the laser should then be responsible for the patient history. It is obvious that operational efficiency becomes greater, if rooms are located close to each other. A schedule for the surgeon crew should be generated either on a white board with a felt-tip pen (never dusty chalk) or on an on-line information system to be able to quickly respond to changes.
Detailed Steps at SurgerySurgical procedures even of the same technique vary depending on each surgeon. It is true thata surgeon will produce his best performance with his personal technique. However, disregarding the personal preference of one specific technique, there exists a best practise technique, that is to say a method with the best outcome and a quick learning curve. The LASIK techniques of the Colombian surgeons, owing wide experience, are very similar. Their investigation and operational experience gained to high patient numbers have already evolved best practise techniques. The North American and the European surgeons, trying the LASIK surgery, focus much on additional procedures as for instance wearing contact lenses after surgery. However, the author believes that any additional procedure will bear a potential risk and therefore should only be done, if real improvement for the patient is expected. The outcome of any LASIK surgery depends very much on the skills of the surgeon. Any academic discussion about the best anaesthetic eye drops will be wasted, if the surgeon generates epithelial ingrowth because he does not know how to use two cannulas to avoid this. The following procedure is based on the actual approach in the Barraquer clinic that is to say the observation of more than seventy LASIK operations by different surgeons at this clinic during 1996. The author is not an ophthalmic surgeon, however his observations were underlined by detailed discussions in the native language of the surgeons (Spanish). Each surgeon had carried out at least 700 hundred LASIK surgeries before 1996, moreover they even included the experience of former keratomileusis techniques as well as other refractive techniques. The following can not take the place of good training, but it can give an idea of what will be important at surgery. Surgery is being done with the Chiron microkeratome, the lasers used are Schwind, Visx 20/20 and Visx Star. The steps of the basic procedure do not depend on the kind of correction. The steps however, do depend to some extent on the laser and certainly on the kind of microkeratome used.
1. Touch of cornea as little as possible2. Do not touch the stroma, if possible. (No "massage" of stroma with sponge!)3. Never touch the stroma with instruments which have been in contact with the epithelia (to avoid epithelial ingrowth)4. Any dust and dirt is to be avoided5. Avoid wrinkles6. The time after the cut, and even after the flap is folded back, should be as short as possible, therefore basic fixation should be done before the cut (LASIK).7. A complete surgery without complications should not take more than seven minutes, that is to say, if only one eye is operated on, the usual patient should not stay more than seven minutes in the operating theatre (LASIK).Figure 35: Rules for Successful In Situ Keratomileusis | Although the surgeon sets his surgical crew, the steps are listed in the areas of responsibility of each member of the surgeon crew. The steps of the surgeon are on the left, those of the trained technician taking care of the computer are in the center and the steps of the assistants are on the right. The technician should be a trained person who knows the handling of the laser perfectly. He should be trained by the laser manufacture to ensure best handling and even improve the information flow between the laser manufacturer and the clinical institution. Although he does not need to be an optometrist, a well trained optometrist supports the responsibility of the surgeon and improves the quality of surgery. Reading the bold words give a quick overview of the whole process. Underlined words show the instruments needed to perform the surgery. surgeon: trained technician: assistant(s):1. welcoming of patient by surgeon crew2. complete name check (asking first name and surname), identification!3. entering general patient data into computer4. patient is helped onto the patient bed· fixation of head with air-pillow first sequence of anaesthetic drops covering of the patient· contralateral eye is to be covered with a protector (e.g. metallic cover) to avoid any pressure of the surgeon and allow that only the eye operated on receives light to improve fixation5. centring the patient bed, the patient and the patient head6. verification of scheduled surgical parameters by surgeon with trained technician· anticipated target refraction in respect of the potential quality of the eye and the patients priorities in quality of vision have already been scheduled in final examination with the patient. (See 6.2 and 6.3.)7. entering ablation profile parameters8. placement of eyelid speculum9. application of second sequence of anaesthetic drops10.marking the cornea with a simple needle tip making a very small linear erosion without any indentation(to be able to find the flap in case of a complete cut; a four radial marker is too risky: danger of damaging the cornea, especially if used before the microkeratome cut))11.handling the suction ring· placement and centring suction ring· checking of suction with Barraquer applanation tonometer: higher than 65mm Hg· checking the diameter of the disk with the applanating lensÞ if diameter is too small (big)the suction ring needs to be changedÞ and the stopper of the microkeratome to be adjusted to obtain the hinge as wantedÞ doing a retreatment of LASIK the diameter should be somewhat (0.5mm) smaller than the original, if the original flap is not used anymore (after six months of first surgery)12.handling the microkeratome· testing of the automatic and smooth blade movement before the real cut· adjust the stopper to the diameter (decide what size of hinge you need)· a few water drops onto the gears and the cornea for perfect movement· setting of microkeratome on track gears· forward cut until automatic stop· careful observation at the time of backward cut to notice any abnormality of the diskÞ if disk is cut completely, it needs to be located and instantly stored in a plastic antidessication chamberÞ if stroma is open and there is any delay, it should be covered with a plastic capÞ if cut has major irregularities surgery has to be stopped.Þ if the cut is very thin, and with minor irregularities surgery can be changed to superficial PRK or stopped and repeated after three monthsÞ if there is bleeding in the periphery (often when diameter is greater than 8.5mm, soft contact lens wearer) it should be taken with the sponge, next patient needs newly disinfected microkeratome!!!)13.eye is centred, that is to say the patient bed is shifted14.disk is folded to nasal side: carefully, using always a new instrument to avoid epithelial ingrowth15.patient is asked to fixate the laserÞ if patient can not fixate or hold center, eye needs to be held with forceps in the outer corneoscleral limbus16.ablation17.disk is now folded back· one cannula is used to fold back the flap (only contact with epithelial surface of flap)· use of another instrument for the stromal interface: usually irrigation cannula· after flap is returned a good irrigation is necessary to help a complete and smooth replacement without provoking wrinkles, also ejecting any foreign particles that could remain between the interface· flap is smoothly pushed onto the stroma with a sponge (e.g. Merocel) always from hinge (nasal) direction, edge of disk is dried out with the sponge to ensure good adhesion of the flap· check of good adhesion by depressing corneal limbus, stress lines must radiate into the flap18.eyelid speculum is taken out19.patient is asked to blink and any displacement of the flap is observed (three times)20.drops are to be placed· mydriasis with cycloplegic agent· antibiotic· anti-inflammatory (cortecosteroids)21.eye is covered with plastic cap which is being filled with cushion to keep eye closed for an hour22. surgeon asks the patient to never touch and rub his eyes· no swimming for 1 month· no make up for three months· take care for make up after three months23.patient is helped into the wheel chair 24.patient is brought into the recuperation roomFigure 36: Detailed Steps at Surgery Some readers might be surprised why the suction ring is taken off at the time of ablation. Waring and Ruiz prefer to leave the suction ring placed during the time of ablation. Waring leaves the suction ring placed without suction [SWM+96], Ruiz leaves the suction during the whole time of ablation [Rui95]. Both use the suction ring to fixate the eye. However, if best fixation can be obtained by the auto-fixation of the patient, it should be preferred. The disk can easily dry and stick on the metal of the suction ring. The suction during the whole process of ablation strains the eye. However, if using the suction ring for fixation there should be suction at all times while the flap is folded back to ensure that the flap is not damaged by sudden movement of a loose suction ring. Employing this "Ruiz" method it is helpful to absorb any moisture above the suction ring at the time of ablation with a cotton swab. The experience with the VISX and the Schwind laser has shown that auto-fixation is fine even in LASIK, that is to say even seeing without the flap. If a patient can not hold and center his eye towards the fixation laser, the position of the eye can be held and controlled with a forceps in the peripheral limbus.
PostsurgeryThere are two different types of postsurgical controls: a small ophthalmic control (fig.37)on the day after surgery and four complete controls (fig.37)during the first year. The first complete control takes place one week after surgery, then after three, six and twelve months.
| Figure 37: Postsurgical Controls | The day after the surgery only a ophthalmic control with rough optometric measurements is employed. Rapid improvement allows first stable optometric measurements after one week's time. The examinations are very similar to the presurgical control. Figure 37 shows a computer assisted consultation about subjective quality indicators by the reception staff. The subjective quality indicators are listed in 6.3.5. and have been discussed in 6.1. The information is essential to further improve the surgery on the patients. The data must be collected by an information system to keep things simple. Obtained data can then be easily aggregated and compared even with the clinical quality indicators to further improve surgery and detect any undesired "offsets" in the operating theatre as early as possible. However, usually there are no real complications and the benefit of these examinations is rather for the experience of the clinic and future patient than to the actual patient. Depending on the culture and education of the patients many of the happy patients will not turn up for these examinations. However, to ensure total quality in Refractive Surgery the examinations after surgery are essential. Moreover, only a complete data base will allow highest quality standards. The patient has to be encouraged to return for postsurgical control according to the customs and behaviour of the patient. The general level of patient's reliability, and personal effort to visit the institution are the given variables. Long waiting times will certainly support the absence of many patients who are willing to undergo the postsurgical examinations. Directly charging the patients for each postsurgical examination will also hold off many patients. Only if patients do not to have to wait more than 30 minutes and spend a pleasant time in the institution they will turn up for postsurgical control. Patients should already have paid for their postsurgical examinations before surgery, that is to say the fee for surgery should include the postsurgical controls. If the patient participates in all postsurgical examinations he should be rewarded with a percentage of the total fee paid for surgery. This even is legitimate as the patient helps the clinical institution to improve their quality standards. In some cases the patient's vision should be trained. Patients have to get used to their 'new eyes'. The changed refraction makes it necessary to readapt to emmetropic conditions. Training of binocular vision is helpful. Presbyopic patients who decided to split up their vision have learn to work with their near sighted eye and to use their dominate eye only for longer distances.[3]
Speaking in the words of Meyer [chapter 4], the specification and contact potentials of the
[2]Depending on patients life situation surgical parameters should be set. For instance, a pilot will require best night vision. He will only be suitable for surgery, if he can be treated with a spherical six mm optical zone. An actor who might not need perfect night vision could even be operated with a 4 mm zone, if the magnitude of his defect does not allow a greater optical zone.
[3]It seem to be that men rely much more on binocular vision than women [Bar96] |
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