An Introductory Philosophy of Medicine

Chapter 5. Diagnosis and Therapeutics

In this chapter, I examine from a metaphysical perspective entities that compose the medical worldviews involved with diagnosis and therapeutics, i.e. the diagnostic and therapeutic "stuff' that makes up the biomedical and humanistic or humane models. For example, knowing the cause of a disease is critical for being able to identify and treat it intelligibly, and forms the rational basis for diagnosis and therapeutics (see Chapters 9 and 10). For the biomedical model because disease is a physical state and the result of mechanistic causation, diagnosis and therapeutics is physical and mechanistic as well. A biomedical practitioner uses physical means by which to gather the clinical data and information necessary to determine a patient's disease state and its cause.

The diagnostic procedure for the biomedical or technomedical model depends upon an outside-in approach (Davis-Floyd and St. John, 1998). The standard outsidein approach is the differential diagnostic method. Through this method, a physician uses the data generated from laboratory tests and physical examinations to eliminate the different hypotheses not causally responsible for a patient's disease state. Once the proper diagnosis is made and the nature of the diseased state determined, the role of a biomedical practitioner is to intervene in the disease process. Just like the diagnostic procedure, this intervention is also often outside-in (Davis-Floyd and St. John, 1998).

This outside-in approach to disease led to a therapeutic revolution in the twentieth century, following on the heel of advances made in understanding and treating infectious disease at the end of the nineteenth century. The revolution, however, was slow in coming during the first half of the twentieth century, and physicians during this time still had little in the way of effective therapeutics to offer patients: "Comfort was what the scientific physician could offer as recently as 1933!" (Golub, 1997, p. 179). Even blood letting was still practiced up to the First World War.

After the Second World War, however, the technological revolution in medicine took off at a staggering pace with the successful development of vaccines, antibiotics, and other pharmaceutical drugs, including designer drugs and surgical procedures and their associated technology. Comparing the revolution to the technical feats of the space program, James Le Fanu claims that "the post-war therapeutic revolution was the most momentous of all, a multitude of discoveries in diverse scientific disciplines stretching over a period of three decades" (2002, pp. 159-160). The twentieth century culminated in the genetic revolution, especially with the introduction of gene therapy (Clark, 1997; Marcum, 2005b).

Although the biomedical model sponsored these "miracles" of modern medicine, many patients today are dissatisfied with the quality-of-care provided by biomedical practitioners and their outside-in approach. Commenting on the limitation of this approach, Davis-Floyd and St. John claim that "it renders invisible the personality and the experiences of the patient who must live and perhaps die with the disease" (1998, p. 28). Humanistic or humane practitioners certainly avail themselves to the technological advances made in diagnostic and therapeutic procedures; but, they attempt to instill a human touch into medical practice. Moreover, since disease causation is more than simply mechanistic causation-rather it is multifactorial and must include the patient's lifestyle-therapeutics is more than simply intervening in the physical causes responsible for a disease state or an illness experience. Rather, healing, which is meant to reinstate a patient's wholeness, must include lifestyle factors. It must involve more than external intervention.

Humanistic or humane practitioners add to biomedicine's outside-in approach an inside-out approach (Davis-Floyd and St. John, 1998). According to this approach, given the patient's attunement to changes within the body the role of the physician is to obtain, especially through patient-physician communication, the needed information for making a more accurate and holistic diagnosis. "The physician-patient communication [that the humanistic model] emphasizes allows the physician to elicit information from deep within the patient and combine it with objective findings" (Davis-Floyd and St. John, 1998, p. 97). Finally, the body is often able to heal itself such that the humanistic or humane physician rather than simply imposing a therapeutic modality is to assist the natural ability of the body to heal itself.

5.1 Diagnosis

Medical diagnosis is the means by which physicians and other healthcare professions determine a patient's disease state, and it represents an important component of modern medicine's worldview and metaphysics. Advances in technology, especially imaging technology, certainly enhance the ability of physicians and medical technicians to gaze into the interior of the patient's body in order to determine with accuracy its disease state. These techniques range from the low tech and noninvasive to the high tech and invasive and include technical devices, from stethoscopes to MRI scanners. The biomedical model depends upon two broad means for determining the patient's disease state: the medical interview and the physical examination, which generally includes follow up laboratory tests and procedures. In this section, the metaphysics of the cognitive and technical devices developed to aid biomedical practitioners in diagnosis are examined, in terms of the medical interview, physical examination, and laboratory tests and procedures. I then discuss the humanization of these diagnostic procedures.

5.1.1 Medical Interview

People seek a physician because they know something is physically or mentally wrong with them (Black, 1968). In order to determine a patient's problem, the physician asks the patient a series of questions. This process is known as the medical interview (Aldrich, 1999; Cole and Bird, 2000; Coulehan and Block, 2001). Although the medical interview predates the twentieth century, it was not until Felix Deutch and William Murphy published The Clinical Interview in 1954, that it became a subject for systematic analysis (Billings and Stoeckle, 1999). Moreover, pedagogical texts began to appear that addressed the steps associated with an effective medical interview. The purpose of the interview for the biomedical practitioner is to collect all the relevant and objective information and data concerning the patient's disease. The questions range from information concerning the patient's present illness and past medical history to the patient's social situation and personal habits.

The medical interview forms the initial component of the patient's medical record, which is "a repository of the information collected about patients, of how the data were interpreted, and of what medical acts were carried out" (Billings and Stoeckle, 1999, p. 271). In other words, a medical record is a comprehensive documentation of a patient's health history and medical care. In the early 1970s, Lawrence Weed (1971) introduced a problem-oriented medical record to structure record keeping. According to this approach, a patient's medical problems are enumerated on a list that provides the information on the actions taken or on those that are planned, in terms of assessing the problem and of developing therapeutic protocols. Besides the list of problems, a medical record also includes a list of the medications administered to the patient. The medical record is a confidential chronicle that aids those in patient care and must be respected as such (Siegler, 1982).

5.1.1.1 Technique

The technique for conducting the medical interview varies but includes a number of essential elements, including the initial or chief complaint, history of present illness, past medical history, family history, social history, and review of the symptoms (Greenberger and Hinthorn, 1993). The chief complaint is technically called the "presenting symptom" When conducting the medical interview, or medical history as it was known previously, the physician should "begin the history with a detailed analysis of the presenting symptom, for this is the thing in which the patient is most interested, the thing which has made him take the trouble to consult his doctor" (Black, 1968, p. 31).

Symptoms are the subjective description of the disease as experienced by the patient, such as depression, dizziness, fatigue, pain, or shortness of breath. The description of symptoms are important, since they assist the physician in forming initial diagnostic hypotheses, i.e. they "are the experiences that suggest disease or physical dysfunction" (Greenberger and Hinthorn, 1993, p. 3). Finally, the physician must be cautious when there is more than one initial complaint since there may be more than one disease.

After establishing the presenting symptom, the next part of the medical history consists of the present illness history. "The [history of the] present illness," according to Coulehan and Block, "is a thorough elaboration of the chief complaint and other current symptoms starting from the time the patient last felt well until the present" (2001, p. 45). Whereas the first part of the medical history depends upon the patient's voluntary information, the present illness history depends upon the questions the physician asks the patient concerning the present illness. Of course, the questions the physician asks depend on the patient's initial description of the presenting symptom. The general strategy is to begin with open-ended questions and move to more specific questions. For example, the physician may seek general descriptive information about the chief complaint and then focus on its specific details in terms of location, time of onset, or intensity. The purpose is to obtain information about additional symptoms not mentioned with the presenting symptom.

In the next component of the medical interview, the physician continues to gather information and data on a patient's present illness by examining the patient's previous medical problems and diseases. This component is known as the past medical history. "The past medical history," according to Steven Cole and Julian Bird, "is the record of the patient's past experiences with illnesses and medical treatments" (1991, p. 87). Here the physician asks specific questions about the patient's previous medical problems that are germane to the present illness. This part of the medical interview should be comprehensive and sufficiently detailed to assist the physician to begin the process of forming a valid differential diagnosis. The topics that make up the past medical history include previous hospitalizations, operations, injuries, serious physical and mental illnesses, allergies, past and current medications and any allergic reactions to them, immunizations, pregnancies, dietary constraints, exercise, and sleeping patterns. As in the history of the present illness, the strategy is to begin with open-ended questions and then to focus on specific questions when needed.

The family history constitutes the next section of the medical interview, in which the physician inquires about blood or genetic relatives and their "illnesses, state of health or cause of death, age, where they live, and who they depend on for support" (Greenberger and Hinthorn, 1993, p. 13). The illnesses of special concern are hereditary diseases. Although classical Mendelian diseases are uncommon, there are many diseases that have a genetic basis such as cancer, heart disease, depression, epilepsy, and type II diabetes. The family history is important for providing trends of these genetic diseases within a family in order to access the risk of the disease for the individual patient. To that end, a family tree is constructed. Certain diseases such as breast cancer and coronary heart disease have genetic markers such as BRCA I and II or high serum cholesterol, respectively, that permit prophylactic surgery and dietary restrictions to prevent the disease's occurrence.

The penultimate step in the medical interview is the social history, in which the physician asks questions about the patient's personal history or biography and habits, employment, and sexual activity and orientation. The patient's personal history includes place of birth, life-style choices, family background, education, leisure activity, residence, and religious beliefs, which are important factors in terms of diagnosing and treating a disease. For example, Jehovah Witnesses do not permit blood transfusion. Personal habits, such as smoking, alcohol consumption, and non-prescription or illicit drug use, are important risk factors for certain diseases. Cigarette smoking, for example, is a risk factor for a number of diseases including heart disease and lung cancer. Moreover, since denial or distortion of certain habits such as alcohol consumption is common, special interviewing techniques are available to obtain the requisite information. Employment is also important in determining possible environmental carcinogens or toxins the patient may be exposed to, such as asbestos. Another serious risk factor associated with many occupations is stress. Sexual activity and orientation are important for determining the risk of sexually transmitted diseases, such as syphilis and gonorrhea.

The final step in the medical interview is the review of systems, in which the physician asks questions systematically about each part of the body to compile an inventory of symptoms. "The purpose of this inventory," according to Billings and Stoeckle, "is to screen for disease processes that have not as yet been discovered in the history. A systematic and thorough review, organized to scan for common complaints referable to each system of the body," they claim, "will jog the patient's memory about symptoms and diseases that have not already been mentioned, and will remind the interviewer about topics that may have been overlooked" (1999, p. 57). The questions generally begin with the skin and then proceed to the head and downwards, inquiring about symptoms for each of the major organs and organ systems. Although this step is considered as the last one pedagogically, it is generally conducted during other parts of the medical interview or during the physical examination. Through this step the physician hopefully compiles a complete and comprehensive medical picture of the patient.

5.1.1.2 Humanistic Modifications

Of course, humanistic or humane practitioners also rely upon the medical interview but modify it to address issues concerning the illness experience other than a patient's somatic condition(s). "The medical interview," according to Knight Aldrich, "is the procedure through which the doctor, while establishing a relationship with the patient and enlisting the patient's collaboration in treatment, seeks to understand the patient's illness as the first step in making a diagnosis of disease" (1999, p. 1). The modifications include asking questions about existential and emotional issues concerning the patient's medical history. For example, Cassell claims that biomedical practitioners are not necessarily interested in why the patient suffers but in what causes the patient's disease: "It is frequently troubling to patients to discover that most doctors are not primarily interested in finding out what is the matter with them but are concerned instead with discovering what disease is the source of their illness" (1991, p. 95).

The place to allay the existential and emotional concerns of the patient is in taking the medical history. Through interviewing the patient, the physician can address these concerns, which are often the source of the patient's suffering. The goal of the medical interview for the humane practitioner is more expansive than that for the biomedical practitioner: "to understand the patient's view of the illness and its significance, and to understand the patients... as people whose psychological, sociological, cultural, developmental, and personality characteristics have influenced their illnesses and their responses to illness, to disease, and to medical care" (Aldrich, 1993, p. 23).'

In Talking with Patients Cassell (1985) asserts that a physician obtains, through the standard medical history, only a portion of the information concerning the patient's illness experience. He adds three additional sections, which he calls the "personal history," in order to acquire a more comprehensive account of the illness and its meaning and impact on the patient's daily life. In the first section, the physician inquires about "the kind of person the patient is, along with how he or she behaves, interacts with the pathophysiology to produce this specific illness" (1985, p. 85). The next section involves personal, familial, social, and cultural factors associated with the patient's illness experience. The final section is concerned with how the patient interprets the illness experience, especially the expectations the patient has for healing. The stance of a physician should be to place herself within the shoes of a patient: "We should constantly be asking ourselves how we would have thought, felt, reacted, or acted if such an event had happened to us" (Cassell, 1985, p. 109).

Finally, Tauber (2005) recommends the addition of an ethics section to the medical interview and record, which would address the ethical issues of the patient's illness. As he points out the current medical record, which dates to the 1960s, reflects the scientific emphasis of medical care. By adding an ethics section, the healthcare team is given an opportunity to tackle the ethical concerns for that particular patient before they become problematic. However, the more important benefit is to help the physician realize that at root the medical profession is a moral enterprise that requires physicians to reflect on the ethical and moral implications of their actions with patients: "clinical medicine is governed by its ethics, and when mentors and students better recognize the complex moral reality in which they live, the more likely their craft will be transformed from its technocratic and bureaucratic obsessions to a more humanized life form" (Tauber, 2005, p. 239).

5.1.2 Physical Examination and Laboratory Tests

Once the medical interview is complete the physician then conducts, if necessary, a physical or clinical examination. It is the procedure in which a physician physically examines the patient for signs of disease (Greenberger and Hinthorn, 1993; Kassirer and Kopelman, 1991b). The exam usually begins with the head, moves to the torso, and concludes with the extremities. The physical examination involves a variety of techniques to access the organ systems, including inspection, palpation, percussion and auscultation. The information obtained from the examination includes the patient's basic vital signs, including body temperature, respiratory rate, and blood pressure, general biometrical data, such as the patient's weight and height, and the general condition of each of the organ systems. Besides the general examination, especially for asymptomatic persons usually undergoing an annual check-up, each specialty has its own specific examination for symptomatic patients, which allows the specialist to determine the exact nature of the disease for the pertinent organ system, such as the circulatory, neural, or respiratory system.

Whereas symptoms are the expressions from the patient's subjective experience of the disease, clinical signs are the objective expression of the disease, which the physician observes upon examining the patient (Cole and Bird, 2000; Coulehan and Block, 1992). Signs are often the result of diagnostic intervention and may include a lump discovered on the liver though palpation or a heart murmur through auscultation. Many signs are named after physicians who first described them, such as Boston's or Graefe's sign in which the eye protrudes from the socket and is indicative Graves-Basedow disease, a form of hyperthyroidism.

Advances in laboratory tests and procedures over the last several decades are simply staggering. These advances include, for example, a host of imaging devices such as ultrasound and magnetic resonance imaging, as well as scanning devices such as computerized (axial) tomography and proton emission tomography (Konofagou, 2004; McGoron and Franquiz, 2004). Besides high-tech machines, there is also a host of laboratory protocols that can be used to measure a variety of bodily substances, such as cholesterol, creatinine, bilirubin, and serum albumin. Finally, the development of the endoscope has allowed physicians and surgeons to invade the body with minimal damage to the patient (Wang and Triadafilopoulos, 2004). However, magnetic resonance imaging (MRI) probably best illustrates the advances in medical technology.

Raymond Damadian and colleagues performed the first MRI exam of a patient in 1977 (Gore, 2003). Although the results were crude, the development of MRI over the next several decades was astounding. To date, over a dozen Nobel Prizes have been awarded to those involved directly or indirectly in its development (Boesch, 2004). The basic principle upon which MRI works involves the absorption of energy by hydrogen atoms from a radio frequency pulse, within a strong magnetic field (Roberts and Macgowan, 2004). The magnetic field forces the hydrogen atoms into a particular alignment. Once the pulse ends, the coil, through which the pulse was generated, detects a signal from the hydrogen atoms and converts it into a signal that is then transformed into an image. The image depends on the type of tissue and whether it is normal or not. MRI is used to diagnose a variety of disease states, including herniated discs in the spine, tumors and infections in brain and other parts of the body, strokes, and multiple sclerosis. This technology has also been adapted for examining the circulatory system.

An important humanistic modification of laboratory testing is to invite the patient into the process by explaining what the results of the tests mean. Often patients are left dangling in terms of the massive amount of information collected on them and only given the relevant facts that seem just that, facts. When in reality, there exists a lot of uncertainty in the laboratory tests in that the data must be interpreted as facts. By exposing the patient to the interpretative process that is part of the testing procedure, the physician allows the patient to comprehend more fully the diagnostic experience. No longer is the patient just a spectator in the "game" of medicine-as Tauber (2005) calls it-but an active participant. Thus, the patient is empowered with authentic knowledge rather than patronized with facts from on high. Of course, the physician must be sensitive to the patient and not simply present the laboratory data without guidance. After all, the physician undergoes years of training to understand the game of medicine but it is the patient who best understands the illness experience.

5.1.3 Differential Diagnosis

From the clinical evidence gathered from the medical history and the physical exam, including laboratory tests, a physician constructs a differential diagnosis. The exact nature of this diagnosis is ambiguous, since clinicians use it quite differently. For example, Jerome Kassirer and Richard Kopelman (1990) have identified five uses for differential diagnosis. The first is an exhaustive list of possible diseases to account for the clinical evidence. Importantly, the list is not ranked probabilistically. The next use is also a long list of possible diseases for each of the significant clinical datum. The third use is also an exhaustive list but ordered probabilistically. The fourth use is a short list that is supported by a large amount of clinical data.

Finally, a use preferred by Kassirer and Kopelman is "a flexible, ever-changing set of hypotheses driven by probabilistic reasoning, causal reasoning, and concern for the patient's welfare" (1990, p. 27). Although they admit that each use has its advantages, they support their preferred use of evolving set of hypotheses and defend it with a case study demonstrating the development of a differential diagnosis by a clinician examining a patient who was ultimately diagnosed with disseminated histoplasmosis.

5.2 Therapeutics

Medical therapeutics is the means by which physicians and other healthcare professions treat a patient's disease state. Over the last fifty years, advances in therapeutic technology revolutionized medicine and its worldview. These advances include kidney dialysis, cancer chemotherapy, antibiotics, gene therapy, and the heart-lung machine, which made possible one of the most outstanding advances in twentieth century medicine-open heart surgery. In this section, therapeutic advances made possible by biomedical technology are discussed in terms of pharmaceutical drugs, surgical procedures, and gene therapy. In addition, I discuss the notion of the physician as a therapeutic device.

5.2.1 Pharmaceutical Drugs

The rise of the biomedical model certainly depended on the discovery and development of pharmaceutical drugs during the late nineteenth century and the twentieth century. These drugs afforded medicine an ability to treat diseases, especially infectious diseases, which were responsible for the majority of premature deaths. Probably the most miraculous of the drugs were the antibiotics (Hoel and Williams, 1997; Wainwright, 1990). With their discovery and development in the early to mid twentieth century, antibiotics were used to eradicate infectious diseases, like diarrhea and enteritis, pneumonia, and tuberculosis, which plagued western society. Recently, however, a crisis has arisen over the abuse of antibiotics as bacteria became resistant to these medicinals (Casadevall, 1996; Walsh, 2003). Although vaccines are not drugs to treat diseases, they are important for disease prevention (Fletcher et al., 2004; Plotkin, 2005). Finally, "designer" drugs like monoclonal antibodies are part of the future for the pharmaceutical industry (Feig, 2002; Richards, 1994; Rifkind and Rossouw, 1998). In this section, I look at three important drugs, penicillin, insulin, and heparin, to illustrate the advances made in pharmaceutical medicine.

5.2.1.1 Penicillin

One of the first antibiotics to be discovered and developed for clinical use was penicillin (Hoel and Williams, 1997; Lax, 2004). Traditionally Alexander Fleming is credited with penicillin's discovery, although there were others that had observed the Penicillium mold's antibiotic effects prior to Fleming (Goldsworthy and McFarlane, 2002). Howard Florey and his assistant Ernst Chain are credited with the isolation and development of penicillin as an antibiotic, although it was the Americans who devised the first commercial protocol of its isolation for clinical use (Brown, 2004).

Chemically penicillin is part of a group of (3-lactam antibiotics, with narrow specificity for Gram-positive bacteria (Kucers et al., 1997). It can be modified to broaden its specificity to treat a wide range of bacterial diseases. It functions primarily by inhibiting peptidoglycan cross-linking within the bacterial cell wall, resulting in cell lysis. Penicillin has been used to treat a wide variety of diseases, including syphilis, bacterial endocarditis, septicaemia, pneumonia, and meningitis.

5.2.1.2 Insulin

There are many other important pharmaceutical drugs discovered and developed during the twenty century, including insulin and heparin, which helped to treat deadly disease like diabetes and to develop spectacular surgical procedures like open-heart surgery (Sneader, 2005). The clinical use of insulin resulted in dramatic outcomes for treating diabetes. Leonard Thompson at age fourteen was about to slip into a diabetic comma, when he received one of the first injections of bovine insulin on 23 January 1922 (Bliss, 1984). His blood sugar eventually returned to normal levels and he lived another thirteen years.

Insulin is a pancreatic hormone produced by (3-cells in the Islets of Langerhans (Federwisch et al., 2002). It is a protein with a molecular weight of 5,808 Da and was the first protein ever sequenced, by Fred Sanger in 1955. It functions by binding to cell membrane receptors and by increasing the uptake of glucose and glycogen synthesis. The insulin gene is located on chromosome lip 15.5; and cloned human insulin is now used to treat diabetic patients. Gene therapy is on the horizon (Chan et al., 2003).

5.2.1.3 Heparin

Heparin is a blood thinner or anticoagulant discovered in William Howell's laboratory at the Johns Hopkins medical school, during the first half of the twentieth century (Marcum, 1990, 2000). Although Howell attracted the interest of an American drug company, Hynson, Westcott and Dunning, the company did not sufficiently purify it for use in humans. The development of heparin as a drug was due to the work of Charles Best, of insulin fame (Marcum, 1997). Heparin does not directly inhibit blood coagulation but acts as a cofactor, which binds antithrombin III and potentiates its inactivation of clotting factors such as thrombin and factor Xa (Rosenberg et al., 1985).

One of the chief problems with heparin is regulating its in vivo activity when injected into patients, i.e. there is a substantial risk of bleeding or hemorrhage. Protamine sulfate is the standard means of regulating the anticoagulant's activity. However, clinicians discovered that the oligosaccharide containing fewer than 18 monosaccharides represents a safer form of the anticoagulant for inhibiting blood coagulation. Several pharmaceutical companies, including Aventis, Novartis, Pfizer, Wyeth-Ayerst, among others, developed preparations of low molecular weight heparin (LMWH). LMWH was aggressively developed clinically and is used today to treat not only blood clotting disorders but also inflammatory and malignant diseases (Messmore et al., 2004).

Howell was certainly interested in the physiological function of heparin and incorporated the inhibitor into his theory of blood coagulation, a theory that dominated an entire generation's understanding of blood coagulation (Marcum, 1992). However, with the rejection of Howell's theory by a subsequent generation the inhibitor's physiological role faded in comparison to its clinical role in managing blood clotting. Moreover, the cells that make heparin, mast cells, are not generally located strategically with respect to the vascular system and heparin is only found in the blood under pathologic conditions. Research during the 1980s demonstrated that another complex carbohydrate, heparin sulfate, that is comparable to heparin is synthesized by vascular endothelial cells and is involved in the regulation of hemostasis (Marcum and Rosenberg, 1991).

5.2.2 Surgical Procedures

The development of surgical procedures and its associated technology was also staggering during the twentieth century and was intimately linked often with the discovery and development of the above pharmaceutical drugs, including surgical procedures such as organ transplants.2 For example, the development of vascular surgery procedures was not possible until the discovery of a safe and an effective blood anticoagulant or thinner. The discovery and development of heparin made possible not only vascular surgery techniques but also high profile surgical procedures, such as open heart surgery, and its associated technology, such as the heart-lung machine (Bigelow, 1990; Le Fanu, 2002). This case study is used to illustrate the advances made in surgical procedures during the mid twentieth century.

Fallot's tetralogy or the "blue baby" syndrome is a condition in which a hole between the two main chambers of the heart does not close off during development (Bigelow, 1990; Le Fanu, 2002). The result is that that both oxygenated blood (red in color) and deoxygenated blood (blue in color) mingle in the heart and is pumped to the rest of the body, which accounts for the baby's blue appearance. The life expectancy of untreated blue babies is around ten years. In 1944, the Johns Hopkins surgeon Alfred Blalock, along with his associates pediatric cardiologist Helen Taussig and medical scientist Vivien Thomas, developed a surgical procedure, known as the Blalock-Taussig shunt operation, in which a non-essential blood vessel from the patient is used to redirect blood to the lungs. Although the procedure does not cure the patient, the life expectancy and the quality of life are dramatically increased. This procedure was not possible without heparin to regulate blood clotting (Bigelow, 1990).

Heparin was critical for the development of the heart-lung machine and for the development of open-heart surgery (Bigelow, 1990). Again, the anticoagulant keeps blood from clotting within the machine's tubing and in the patient's blood vessels. Beginning in the 1930s the surgeon John Gibbon and his wife Maly (nee) Hopkins developed a machine that pumps blood away from the heart to a set of coils that then oxygenate the blood, after which it is returned to the heart. By 1953 Gibbon performed several heart operations but with limited success, only one of the five patients survived. After this failure, he stopped using the heat-lung machine in operations. Others, however, modified the Gibbon heart-lung machine. For example, the Mayo Clinic surgeon John Kirklin convinced the clinic to refine the Gibbon pump. By 1958 he successfully performed open-heart surgery on over 200 patients, which "became a gold standard for cardiac surgical teams" (Bigelow, 1990, p. 164).

5.2.3 Gene Therapy

If genes are the wave of the future for modern medicine, then gene therapy is the approach for treating genetic disease. During the 1990s gene therapy became a recognized professional specialty, with the founding of journals and societies. For example, the first professional journal, Human Gene Therapy, was published in 1990 under W. French Anderson's editorship. Today there are around half dozen journals devoted to gene therapy. A few years later, a group of European scientists took the first steps towards founding the European Society of Gene Therapy. Its first international meeting was held in 1993 in Baveno-Stresa. In 1996 the American Society for Gene Therapy was founded, with its first annual meeting held in Seattle a few years later. Other countries have also founded societies for promoting gene therapy.

The types of genetic diseases treated in clinical trials by gene therapy include various forms of cancer, cystic fibrosis, hemophilia, among other diseases (Marcum, 2005b). For example, during the second half of the 1980s Anderson and other researchers succeeded in inserting a gene for adenosine deaminase (ADA) into T cells from patients suffering from severe combined immunodeficiency disease (SCID), commonly known as the "bubble-baby" syndrome. The engineered cells expressed adequate levels of enzyme activity to encourage a try at gene therapy. In September 1990 Anderson and colleagues at the NIH conducted the first Recombinant DNA Advisory Committee (RAC) approved human gene therapy trial, on a young girl suffering from ADA-SCID (Anderson, 1995). A second girl was treated four months later. Although the procedure did not fully cure the girls, it did significantly reduce the amount of the drug PEG-ADA used to treat them.

As the 1990s progressed, investigators received RAC approval for gene therapy protocols and conducted additional studies using animal models to determine the efficacy and safety of gene therapy for human diseases. By mid decade gene therapy clinical trials included patients suffering from over a dozen genetic diseases such as cancer, cystic fibrosis, familial hypercholerolemia, hemophilia, and rheumatoid arthritis. However, towards the end of the decade the first death due directly to gene therapy was reported. A person suffering from brain cancer died a few days after receiving an antivirus drug to attack a brain tumor treated earlier with a genetically engineered virus (Johnston and Baylis, 2004).

In a highly publicized case in 1999, an eighteen year-old boy with a defective gene for ornithine transcarboxylase, an enzyme involved in ammonia catabolism, was given an adenovirus containing the normal gene as part of clinical trails. The teenager died several days later, apparently from a severe allergic reaction to the vector that led to the failure of multiple organs (Lehrman, 1999; Verma, 2000). Although the deaths are tragic and had repercussions for gene therapy trials, the impetus for conducting further trials was not diminished.

At the end of the twentieth century, Alain Fischer and Marina Cavazzana-Calvo, along with colleagues, from the Necker Hospital in Paris treated two baby boys for X-linked SCID (Cavazzana-Calvo et al., 2005). The disease is caused by a defective gene for the y-chain of the interleukin-2 receptor involved the maturation of T cells and natural killer cells. Importantly, X-linked SCID represents an attractive disease for gene therapy since the bone marrow cells receiving the normal gene would have a growth advantage over those cells with the defective gene. The team infused engineered autologous bone marrow cells containing the normal gene into the two baby boys and within the year their immunological systems were normal. The team then went on to treat almost a dozen baby boys with the procedure, with the majority being cured. However, in 2002, two of the boys developed a rare form of leukemia. Examination of their genomes revealed that the retrovirus had inserted into a gene, LMO-2, known to be associated with childhood leukemia. In early 2005, the French team reported yet another boy from its study had developed cancer. In reaction several months later, the FDA suspended several gene therapy trials (Weiss, 2005).

5.2.4 Physician as Therapeutic Agent

According to humanistic or humane practitioners, the physician is a therapeutic instrument or agent in the patient's healing. The role of the physician in the therapeutic process is invaluable: "In acute illness, chronic illness, or terminal illness, the active presence of the physician is a part of the treatment. I believe," Cassell continues, "that it is accurate to put it even more strongly: The physician is the treatment" (1991, p. 126). All other elements of therapy are ancillary to the physician vis-n-vis the patient's illness. The physician is the guide that helps the patient to negotiate the technology of modern medicine.

According to Cassell, "the ideal of scientific knowledge will not work for this sick person without the aid of this doctor" (1991, p. 133). Moreover, he identifies the source of healing not only within the patient but also within the physician and through the physician's self-control and not through control over the patient: "healing powers consist not only in.. .those things or forces for getting better (whatever they may be) that already exist in the patient... [but] virtually all a doctor's healing power flows not from control over the patient, but from the doctor's self-mastery" (Cassell, 1991, p. 234).

Cassell justifies the notion of physician as a therapeutic agent by claiming that clinical information, to be optimally therapeutic, must also include the emotional or subjective dimension of the patient's illness experience: "Information about the patient that is being acquired, evaluated, and utilized and which enters into value and aesthetic assessments may also include feelings, body sensations, and even the spiritual (transcendent)" (1991, p. 226). The physician as an authentic person can access this information and knowledge as genuine, only by relying on personal experience.

Rather than tainting objective knowledge, personal information allows the physician to draw compassionately along side the patient's suffering. "Only the physician as a person," according to Cassell, "can empathetically experience the experience of a sick person" (1991, p. 227). This bond of human experience does not make the physician's knowledge subjective, since the physician must learn to manage such knowledge appropriately. This is a skill that cannot be transmitted in a textbook but only in the clinic under the tutelage of a skilled and empathic instructor, who understands the role of the physician as therapeutic agent.

Paul Freeling (1983) provides a striking example of a physician as healing instrument. A female patient was unable to face a certain social situation that was making her ill. Her physician realized she needed to sever a particular social relationship, based on an intimacy between the physician and patient that had developed over years. The physician told her in no uncertain terms to break off the relationship. The patient was grateful to the physician for the advice that she in fact was hoping to hear and complied with the physician's counsel.

Although Freeling recognizes that the physician's actions are certainly open to criticism, he interprets the physician in this situation as a "therapeutic agent" "Nevertheless the case history illustrates the use of the doctor-patient relationship in diagnosis and treatment," he maintains, "the treatment lying in the category of interfering with the mechanisms linking symptom and cause" (Freeling, 1983, p. 171). Indeed, the close relationship between a physician and a patient often places the physician in the position of being a healing instrument.

5.3 Summary

The metaphysics of diagnosis and therapeutics are important for framing medical knowledge and practice. During the twentieth century, a number of diagnostic and therapeutic procedures and technologies were developed to define medical worldviews. Determining the nature of the patient's disease and its cause is important not only for the diagnosis of a disease but also for therapeutic intervention. For the biomedical model, diagnosis is a technique that depends upon obtaining objective evidence of the patient's disease state through both the medical interview and physical examination.

Although diagnostic procedures and technology provide biomedical practitioners with rational means to determine the precise nature of the disease and thereby to make an accurate diagnosis and to prescribe safe and effective pharmaceutical drugs and surgical procedures to cure the patient's disease state, patients are often dissatisfied with the quality-of-care they receive. In response, humanistic or humane practitioners incorporate techniques to obtain information concerning the personal and existential dimensions of the patient's illness experience. Of course, humane practitioners do not shun the diagnostic and therapeutic procedures discovered and developed by the biomedical sciences. Their aim, however, is to reinsert the physician qua person as a diagnostic and especially as a therapeutic factor into the modern medical worldview.



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