Chapter 1. An Approach to Critical Care

• Thoughtful clinical decision making often contributes more to the patient's outcome than dramatic and innovative interventions or cutting-edge technology.
• Formulate clinical hypotheses, then test them.
• Define therapeutic goals and seek the least intensive intervention that achieves each.
• Novel treatments require objective clinical trials before they are implemented, and traditional therapies require clarification of goals and adverse effects in each patient before their use can be optimized.
• Determine daily whether the appropriate therapeutic goal is treatment for cure or treatment for palliation.
• Critical care is invigorated by a scholarly approach, involving teaching, learning, and performing research.

Intensive care has its roots in the resuscitation of dying patients. Exemplary critical care provides rapid therapeutic responses to failure of vital organ systems, utilizing standardized and effective protocols such as advanced cardiac life support and advanced trauma life support. Other critically ill patients in less urgent need of resuscitation are vulnerable to multiple organ system failure, and benefit from prevention or titrated care of each organ system dysfunction according to principles for reestablishing normal physiology. This critical care tempo differs from the time-honored rounding and prescription practiced by most internists and primary care physicians. Furthermore, the critical care physicians providing resuscitation and titrated care often have little first-hand familiarity with their patients' chronic health history, but extraordinary tools for noninvasive and invasive description and correction of their current pathophysiology. Though well prepared for providing cure of the acute life-threatening problems, the intensivist is frequently disappointed to be the bearer of bad news when recovery is impossible, and increasingly must develop and use compassionate pastoral skills to help comfort dying patients and their significant others, using clinical judgment to help them decide to forego further life-sustaining treatment. Accordingly, experienced intensivists develop ways to curb their inclination toward action in order to minimize complications of critical care, while organizing the delivery of critical care to integrate and coordinate the efforts of many team members to help minimize the intrinsic tendency toward fragmented care. In academic critical care units, teaching and investigation of critical care are energized by the clinical practice; in turn, the practice is informed, animated, and balanced by the information and environment arising from and around teaching and research programs. Yet the vast majority of critical care is delivered in community-based ICUs not affiliated with universities, where critical care physicians rely on their penchant for lifelong learning to update their knowledge and skills through informed reading and attending continuing medical education critical care conferences. These activities in providing, teaching, and investigating critical care contribute to a unique perspective on and approach to medicine among critical care physicians.

Develop and Trust Your Clinical Skills

Clinical excellence is founded in careful history taking, physical examination, and laboratory testing. These data serve to raise questions concerning the mechanisms for the patient's disease, on which a complete prioritized differential diagnosis is formulated and treatment plan initiated. The reality, complexity, and limitations apparent daily in the ICU present several pitfalls on the path to exemplary practice. By its very nature, critical care is exciting and attracts physicians having an inclination toward action. Despite its obvious utility in urgent circumstances, this proclivity can replace effective clinical discipline with excessive unfocused ICU procedures. This common approach inverts the stable pyramid of bedside skills, placing most attention on the least informative source of data, while losing the rational foundation for diagnosis and treatment.

Formulate Clinical Hypotheses and Test Them

An associated problem is that ICU procedures become an end in themselves rather than a means to answer thoughtful clinical questions. Too often these procedures are implemented to provide monitoring, ignoring the fact that the only alarm resides in the intensivist's intellect. Students of critical care benefit from the dictum: “Don't just do something, stand there.” Take the time to process the gathered data to formulate a working hypothesis concerning the mechanisms responsible for each patient's main problems, so that the next diagnostic or treatment intervention can best test that possibility. Without this thoughtful clinical decision making, students of critical care are swept away by the burgeoning armamentarium of the ICU toward the unproductive subspecialty of critical care technology. So often in the ICU thoughtful compilation of the patient's health evaluation preceding the acute event is more helpful than acquiring new data defining the current pathophysiologic state. Accordingly, attention to this search for meaningful collateral history and the retrieval of prior radiologic studies and laboratory values often should precede the next invasive ICU procedure. The next intervention should be chosen to test a diagnostic hypothesis formulated by thoughtful processing of the available data.

Testing a therapeutic hypothesis requires knowing the goal of the intervention and titrating the therapy toward that end point. Too often students of initial care employ too little too late during resuscitation. For example, the patient with hypovolemic shock receives a bolus of 250 mL of crystalloid solution followed by 200 mL/h infused through two 18-gauge needles in peripheral veins, while the mean blood pressure (bp) rises from 50 to 60 mm Hg over 2 hours. A far better volume resuscitation protocol targets urgent restoration of a normal bp and perfusion, so it establishes central venous access for a bolus of 3 L of warmed crystalloid and colloid in 20 minutes, to continue at that rate until the bp exceeds 90 mm Hg without inducing pulmonary edema. As another example, a patient requires intubation and ventilation with 100% oxygen for acute hypoxemic respiratory failure. Positive end-expiratory pressure (PEEP) is increased from 0 to 5 to 10 cm H2O overnight, while arterial O2 saturation (SaO2) increases from 70% to 80% to 90% and bp remains at 95 mm Hg. A better PEEP resuscitation protocol targets an SaO2 of >90% on an inspired O2 fraction (FiO2) of <0.6, so it increases PEEP by 5-cm-H2O increments from 0 to 20 cm H2O at 5-minute intervals, dropping FiO2 as tolerated until the end point is achieved unless bp falls. If bp does fall unacceptably, positive inotropic therapy or volume infusion corrects the hypotension, allowing further PEEP increments toward the end point. In each of the better protocols, a clinical hypothesis about the mechanism of the critical illness—(1) the patient is hypovolemic, so rapid volume infusion will correct the hypotension, or (2) the hypoxemia is due to airspace flooding, so PEEP will correct the shunt—can be tested by titration of therapy toward a thoughtful end point without causing common adverse effects (Fig. 1-1). The results are more timely correction of life-threatening conditions.

Liberate from Interventions So There Are Not More Treatments Than Diagnoses

One of the consequences of protocol-driven resuscitations is that the recovered patient now has more treatments than diagnoses. An effective approach to the adverse outcome of excess therapeutic interventions is the mindset that liberates the patient from these potentially harmful interventions as rapidly as their removal is tolerated. For example, the patient with hemorrhagic shock treated with volume resuscitation and blood products also received intravenous vasoconstricting agents to maintain perfusion pressure while hemostasis and volume resuscitation were achieved. Once a stable blood pressure and hemostasis are achieved, what is the time course for discontinuing the β-agonist therapy?

One answer is to wean the vasoconstrictor slowly (e.g., decrease the norepinephrine infusion rate from 30 μg per minute by 5 μg per minute each hour). Another approach is to liberate the patient from the vasoconstrictor by reducing the norepinephrine infusion rate by half every 15 minutes. The difference between these two approaches is more than the time taken to discontinue the agent, for if in the second approach the bp were to fall after reducing the norepinephrine to 15 μg per minute, the critical care physician learns that the patient remains hypovolemic and needs more volume infusion; the first approach would mask the hypovolemic hypoperfused state by the prolonged use of vasoconstrictor agents, leading to the adverse consequences of multiple organ hypoperfusion. Words convey meaning, and to wean connotes the removal of a nurturing, even friendly life-support system from a dependent, deprived infant, a process that should proceed slowly; by contrast, liberation is the removal of an unnecessary and potentially toxic intervention from an otherwise independent adult, a process that should proceed urgently.1

Define Therapeutic Goals and Seek the Least Intensive Intervention That Achieves Each

The principle from this example applies to many other critical care therapies, such as liberation from the ventilator, vasoactive drugs, and sedative and muscle-relaxing agents. Of course, the difficulty in all these examples is that the therapeutic intervention is initially life-saving, but how long the intervention needs to continue for the patient's benefit versus the patient's harm depends on a critical evaluation of the goal of therapy.

Figure 1-1 indicates the intensity-benefit relationship of many of these interventions (e.g., the continued use of high-dose norepinephrine in the hypotensive patient with hemorrhagic shock discussed earlier). During the initial resuscitation, the benefit of increasing the norepinephrine dose along the x axis (intensity) was demonstrated by the rising bp during hemostasis, volume resuscitation, and norepinephrine infusion. Yet bp is not the appropriate benefit sought in the hypoperfused patient, but rather adequate perfusion of all organs. Even without measuring cardiac output, an adequate perfusion state could be inferred from an adequate bp when the vasoconstrictor agent is diminished. However, with continued infusion of the vasoconstrictor, the adverse effect of a prolonged hypoperfusion state, even with an adequate bp, is indicated by the interrupted line, which illustrates a decreasing benefit as the intensity of the intervention and the shock it masks continues. Armed with this rationale, the intensivist should progressively reduce the intensity of norepinephrine infusion over a relatively short period to determine whether the volume resuscitation is adequate.

A second example is the use of fluid restriction and diuresis in the treatment of pulmonary edema. In Fig. 1-1 the intensity of the intervention is the reduction of the pulmonary capillary wedge pressure (PCWP), while the benefit would be the reduction of pulmonary edema. Considerable data suggest a monotonic relationship between the intensity of these therapeutic interventions and the benefit of reduced pulmonary edema.2 Yet, if the PCWP is reduced too much, there is a consequent reduction in the cardiac output, so the benefit to the patient is more than offset by the attendant hypoperfusion state. The thoughtful intensivist recognizes that the goal of reducing PCWP and pulmonary edema should not induce a hypoperfusion state, so the targeted intensity is the lowest PCWP associated with an adequate cardiac output and oxygen delivery to the peripheral tissues. Similarly, for PEEP therapy, considerable data suggest that the higher the PEEP intensity, the greater will be the reduction in intrapulmonary shunt as the benefit to the patient. Yet the thoughtful intensivist recognizes that PEEP has adverse effects, as indicated by the interrupted line in Fig. 1-1 showing decreasing benefit as the intensity increases due to pulmonary barotrauma and decreased cardiac output. Accordingly, the goals of PEEP therapy should be the least PEEP that provides the end points of PEEP therapy—90% saturation of an adequate circulating hemoglobin on a nontoxic FiO2. Of course, the adverse effects of PEEP can be diminished by concomitant decreases in tidal volume, as currently practiced in “lung-protective ventilation” (see Chaps. 37 and 38).2

First Do No Harm

Beyond enhancing the clinical scholarship of critical care, this approach maximizes another hallowed principle of patient care—“First do no harm.” Despite excited opinions to the contrary, effective critical care is rarely based on brilliant, incisive, dramatic, and innovative interventions, but most often derives from meticulously identifying and titrating each of the patient's multiple problems toward improvements at an urgent but continuous pace. This conservative approach breeds skepticism toward innovative strategies: Novel treatments require objective clinical trials before they are implemented, and traditional therapies require clarification of goals and adverse effects in each patient before their use can be optimized. Accordingly, intensivists should carefully consider the experimental support for each diagnostic and therapeutic approach to critical illness and acknowledge that each approach has adverse effects in order to define the least intensive intervention required to achieve its stated therapeutic goal.

Organize the Critical Care Team

The ICU is no longer simply a room in which ventilators are used. Instead, in a well-functioning ICU, the physical plant and technology are planned to facilitate the delivery of care, while also responding to new opportunities in this rapidly evolving field. The physician director, the nurse manager, and the respiratory therapist must build a mutually supportive environment conducive to teaching, learning, and care. Intensivists must be aware of the economic and legal concerns as ICUs capture the interest of politicians, ethicists, and the courts. Furthermore, the managers of ICUs should build on experience. Quality assurance, triage and severity scoring, and infection surveillance are essential to the continued smooth running of ICUs and indeed to their improvement over time.3

Perhaps no critical care issue is more emotionally charged and time-consuming than the decision to withhold and/or withdraw life-sustaining therapy (see Chap. 17). Practitioners and students of critical care are frequently called on to guide patients and their families through this new, complex decision-making process without much prior personal experience or literature on which to rely. Accordingly, we discuss an approach to managing death and dying in the ICU meant to minimize one current adverse outcome of modern critical care—our patients die alone in pain and distress because maximal care aimed at cure proceeds despite little chance of success.

Decide Whether the Patient Is Dying

In a recent analysis of 6110 deaths in 126 ICUs between January and July of 1996, approximately half were associated with the decision to withhold or to withdraw ICU care, as distinguished from deaths after CPR or with full ICU care but no CPR.4 One interesting feature of this study was the heterogeneity among different units, with some units reporting 90% of deaths associated with withholding and withdrawing ICU care, and others reporting less than 10% associated with this decision. Considerable discussion in the recent literature focuses on the definition of medical futility, and many intensive care physicians are perplexed regarding how to utilize the vagaries of survivorship data to be confident that continuing therapy would be futile.5

Yet many of these same physicians have a clear answer to another formulation of the question “Is this patient dying?”6 An increasing number of critical care physicians are answering “yes” to this question based on their evaluation of the patient's chronic health history, the trajectory of the acute illness, and the number of organ systems currently failing. When the physician concludes that the patient is dying, this information needs to be communicated to the patient, or as so often happens in the ICU, to the significant other of the dying patient who is unable to communicate and has not left advance directives. This communication involves two complex processes: 1. helping the patient or the significant others with the decision to withhold or withdraw life-sustaining therapy, and 2. helping them process the grief this decision entails (Table 1-1).

Change the Goal of Therapy from Cure to Comfort

In our view, this decision is best aided by a clear, brief explanation of the patient's condition and why the physician believes the patient is dying. When the patient or significant other has had the opportunity to challenge or clarify that explanation, the physician needs to make a clear recommendation that continued treatment for cure is most unlikely to be successful, so therapeutic goals should be shifted to treatment for comfort for this dying patient. In our experience, about 90% of such patients or their families understand and agree with the recommendation, most expressing considerable relief that they do not have to make a decision, but rather follow the recommendation of the physician. It is important to provide time and support for the other 10% while they process their reasons for disagreement with the physician's recommendation, but this remains a front-burner issue to be discussed again within 24 hours in most cases.

At this point, patients or their significant others who agree with the recommendation to shift goals from cure to comfort benefit from understanding that comfort care in the ICU constitutes a systematic removal of the causes of patient discomfort, together with the incorporation of comforting interventions of the patient's choice (Table 1-2). For example, treatment for cure often consists of positive-pressure ventilation associated with posturing, chest pummeling and tracheal suctioning, the infusion of vasoactive drugs to enhance circulation, dialysis for renal failure, aggressive intravenous or alimentary nutrition, antibiotics for multiple infections, surgery where indicated, and daily interruption of sedative infusions to allow ongoing confirmation of CNS status. Each of these components of treatment for cure includes uncomfortable interventions that need to be explicitly described so that patients or their significant others do not maintain the misconception that continued ICU care is a harmless, comfortable course of action. By contrast, treatment for comfort consists of intravenous medication effective at relieving pain, dyspnea, and anxiety. It also consists of withholding interventions that cause the patient pain or irritation, and of replacing both interventions and electronic monitoring of vital signs with free access of the family and friends to allow the intensive care cubicle to become a safe place for grieving and dying with psychospiritual support systems maximized. Once an orderly transition from treatment for cure to treatment for comfort has been effected in the ICU, timely transfer out of the unit to an environment that permits death and grieving with privacy and dignity is often appropriate. Whenever possible, continuity of care for the dying patient outside the ICU should be effected by the ICU physician-house staff team to minimize fragmentation of comfort measures and to keep the patient from feeling abandoned.

Manage Grief

The second process that is ongoing during this decision making allows the dying patient or the family and friends to begin to express their grief (see Table 1-1). The very best care of the patient is care for the patient, and the critical care physician's demeanor during the decision making process goes a long way toward demonstrating that he or she is acting as the patient's advocate. The urgent pursuit of an agenda that care should be withdrawn does not help the patient or family to trust in the physician's desire to help the patient. Instead, pastoral skills such as empathic listening, assembling the family and other support systems, and acknowledging and sharing in the pain while introducing the vocabulary of grief processing are constructive ways to help the patient and family reconsider the goals of therapy. This is not an easy task when the physician knows the patient and family well, but it is even more difficult in the modern intensive care environment, when the physician may have met the patient for the first time within hours to days preceding the reconsideration of therapeutic goals. Yet the critical care physician needs to establish his or her position as a credible advocate for the patient by being a source of helpful information, by providing direction, and by listening empathically. Because the critical care physician is often a stranger, all efforts should be made at the time of reconsidering the goals of therapy to assemble support helpful to the patient, including family friends, the primary physician, the bedside nurse, house staff and students caring for the patient, appropriate clergy, ethics specialists, and social services.

Combine Excellence and Compassion

Since up to 90% of patients who die in modern ICUs do so with the decision to withhold and withdraw life-sustaining therapy, exemplary critical care should include a commitment to make this transition to treatment for comfort a humane and compassionate process, conducted with the same expertise and excellence sought during treatment for cure. In our view, the physician's conclusion that the patient is dying is the starting point. Thereafter, the physician's recommendation to shift treatment goals from cure to comfort is essential so that the patient and the family have no illusions that full ICU care will produce a cure. Third, understanding that comfort care is extensive and effective allows the ICU to become a safe place for grieving and dying. This is a distinctly different approach from that of many physicians who feel they have failed their dying patients by not providing cure; all too often this fear of failure leads to abandoning dying patients without providing effective comfort care. Since death is not an option but an inevitability for all of us, critical care physicians can bring their expertise and understanding to help patients decide when to forego life-sustaining therapy and to replace it with effective comfort care, making the ICU a safe and supporting space for the dying patient and his or her significant others. Note that the ministerial skills and attitudes required to implement this approach are more in the province and curriculum of social workers, psychologists, and clerical pastoral associates than critical care physicians. To the extent that experienced intensivists find this approach helpful, teaching it to students of critical care becomes an important contribution to a curriculum of critical care.

The process of providing exemplary critical care is magnified and refined by learning interactions with students of critical care at all levels—from freshmen to senior medical students through residents in anesthesia, medicine, and surgery, to critical care fellows and practicing intensivists seeking continuing medical education. In such teaching sessions, these students always question the principles of critical care and how best to impart them, thereby helping direct a search for better teaching methods. Of course, any active ICU is a classroom for learning the principles of critical care. Yet teachers of critical care need to avoid the pitfalls to learning when there is little time for the student to process the reasons for the formulations of differential diagnostic and treatment plans in each patient. There can develop a “shoot from the hip” pattern recognition of critical illness that often misses the mark and perpetuates a habit of erroneous interventions that delay a more rational, mechanistic, questioning approach to each patient's problem.

Implement a Critical Care Curriculum in the Intensive Care Unit

One helpful teaching technique is to implement a schedule providing students of critical care with the luxury of time to think. This priority provides a counterpoint to the work rounds and clinical problem-solving activities that unfettered, tend to dominate the daily activities of the unit. A good start is to ritualize a curriculum for critical care learning. In many academic centers, house staff and fellows rotate through the ICU on monthly intervals. Accordingly, a monthly series of well-planned seminars addressing the essential topics that house staff and fellows need to know can incorporate medical students and nursing staff, and lay the foundations of conceptual understanding necessary to approach the critically ill patient effectively. In our teaching program, we emphasize a conceptual framework based on the pathophysiology of organ system dysfunction shared by most types of critical illness (Table 1-3).

This approach complements the specific etiology and therapy of individual illnesses, because the opportunity for favorably treating many concurrent organ system failures in each patient occurs early in the critical illness, when the specific diagnosis and focused therapy are less important than resuscitation and stabilization according to principles of organ system pathophysiology. Critically ill patients present many diagnostic and therapeutic problems to their attending physicians and so to the students of critical care. Recent advances in intensive care management and monitoring technology facilitate early detection of pathophysiology of vital functions, allowing the potential for prevention and early treatment. However, this greater volume of diagnostic data and possible therapeutic interventions occasionally can create “information overload” for students of critical care, confounding rather than complementing clinical skills. The purpose of a syllabus addressing the pathophysiology of critical illness is to provide students with an informed practical approach to integrating established concepts of organ system dysfunction with conventional clinical skills. New duty hour regulations for U.S. house officers have made it difficult to include all members of the team in these teaching sessions, an issue we have not been able to fully solve. A syllabus of reading material that follows the seminar topics closely is helpful to students.7

Encourage Independent Interpreting of Imaging Techniques, Biopsies, and Other Interventions

A second forum for teaching critical care is to review essential imaging procedures. Accordingly, we set aside about 45 minutes at 11:00 am each day to systematically review the diagnostic radiology imaging procedures conducted in the last 24 hours on each of our patients, including computer-assisted tomograms, magnetic resonance images, and ultrasonography. This formal review allows faculty and fellows to teach medical students and house staff a systematic review of the chest radiograph and special features of ICU radiology, including identification and positioning of diverse diagnostic and therapeutic instruments (e.g., the endotracheal tube, intravascular catheters, feeding tubes, pacemakers, and others). We also set aside one day per week to review the echocardiographic studies performed during the previous week. Of course, these have been reviewed online when the procedures were done, but this forum allows students of critical care to become more comfortable with the types of diagnostic information we seek from these imaging techniques. Encouraging students of critical care to be active participants in bedside diagnostic and therapeutic procedures such as endoscopy, and to follow-up on all biopsy specimens by direct observation with the pathologist are other ways to encourage active learning concerning the interpretation of ICU procedures and their integration with the patient's clinical evaluation in a timely manner.

Teach How to Teach

An essential component of the critical care fellowship is learning how to teach. It is common in academic medical environments to assume that completing medical school and residency confers the ability to teach,8 but most critical care fellows value the opportunity for supervised and guided enhancement of their teaching abilities by effective teaching faculty. The critical care syllabus outlined earlier gives the opportunity for fellows to observe faculty teaching during their first rotation through the unit and during subsequent months to organize and present selected topics from the syllabus with the help of their faculty preceptor. Our target is that our fellows have mastery of the complete syllabus by the time they complete their fellowship, an exercise that confers confidence and credibility on their teaching skills, and undoubtedly enhances their learning of the concepts they teach. Just as bench researchers go elsewhere and establish their laboratories, our clinical scholars have created the same learning programs elsewhere, exporting this approach and content rather than evolving it over years. A second forum is our daily morning report, where three to five new pulmonary and critical care patients are presented in a half-hour conference. One fellow provides a brief analysis and solution to each clinical problem, and suggestions or affirmations of the analysis by faculty and other fellows help develop the skill of processing and presenting complex patients.

Learn and Use a Questioning Approach

Another important forum for encouraging active learning of critical care is the daily teaching round led by the intensive care faculty and critical care fellows. The format we have found most useful is to encourage the most junior member of the team responsible for the patient to provide a complete, systematic review of the patient, concluding with a differential diagnosis and treatment plan, while the attending faculty member provides an active listening presence. When the presentation is complete, the faculty member questions or confirms directly the essential points from the history, physical examination, and laboratory results, and provides any clarification helpful to the rest of the team on generic or specific teaching issues, integrating the input of more senior members of the team to encourage participation in the bedside decision making as a learning exercise.

Often the case discussions can be led to formulate questions not yet answered concerning the patient's problems. It is less important to provide answers to the questions formed than to point the students of critical care in the direction of how to find the answers, beginning with their reading of appropriate topics in a critical care text available in the ICU. This continues to the appropriate use of medical informatics to search the critical care literature electronically for answers expected in a short interval. Whenever the answer is not available, it is the teaching responsibility of the faculty and critical care fellows to help students of critical care formulate the clinical investigation that could answer the question. In this way, the rounds in the ICU become intellectually charged, and active participation of all members of the team is encouraged. A spin-off of this questioning approach to active learning in the ICU is much more informed cross-coverage between critical care teams. In units with active clinical investigation programs, this questioning approach stimulates interaction between the personnel delivering care and those conducting the research.

Affirm Learning

Students of critical care learn in a charged environment where some patients do not improve or actually deteriorate despite thoughtful, focused, and timely care. Teachers of critical care can diffuse the angst among students by appropriate, well-placed affirmation of the care being delivered. For example, exemplary case presentations, thoughtful and complete differential diagnoses, focused and insightful treatment plans, and well-formulated questions appropriately researched in the available literature are all targets for faculty approbation. When praised appropriately and without flattery, students of critical care respond with energy and enthusiasm, allowing them to learn to the limit of their potential.

Teach Critical Care in the Curricula of Medical Schools and Residency Programs

In many academic institutions, critical care faculty are well known among medical students and house staff as outstanding teachers. This can allow diverse outlets for teaching scholarship in the medical school curriculum and in residency training programs. In our medical school, freshmen students learn the physiology of the cardiovascular and respiratory systems during the winter quarter and have time for elective courses during the spring quarter. This created the opportunity for a freshman spring elective entitled “An Introduction to the Pathophysiology of Critical Illness,” which attracts about a quarter of the freshman class each year. During two 2 ½-hour sessions each week for the 10-week quarter, we review in detail with the students extensions of their cardiopulmonary physiology as it is deranged in critical illness, utilizing a core curriculum similar to the topics shown in Table 1-3. These students are stimulated by finding that their hard work in learning physiology has practical applications in treating critically ill patients, and are enthusiastic to apply this new knowledge of pathophysiology during preceptored visits on four occasions to patients with respiratory failure or hypoperfusion states. Utilizing clinically real teaching aids like a ventilator-lung model, an echocardiography teaching tape, and a heart sound simulator provides freshmen students with a vision of patient care at an early stage in their clinical exposure. During sophomore year, focused topics related to critical care are taught during our clinical pathophysiology course, including asthma and acute respiratory distress syndrome. In the junior year, students rotate twice through the ICU for 2-hour preceptored visits to patients illustrating manifestations of respiratory failure or hypoperfusion states. As described earlier, most senior medical students in our school spend a month as members of the critical care teams in our medical or surgical ICU.

In the medical ICU, medical residents and interns rotate for a least three 1-month periods during their 3-year residency program. To refresh and maintain the knowledge base acquired during these rotations, our critical care faculty leads two medicine morning reports per month, during which they review a syllabus of critical care meant to allow residents not on the ICU to utilize their critical care knowledge to process cases representing a specific aspect of critical care. Our faculty members are also regular participants in the house staff teaching conferences conducted by the departments of anesthesia and critical care, pediatrics, obstetrics and gynecology, and surgery, and this interaction fosters a collegial approach to critically ill patients among these different departments. Finally, the participation of academic critical care faculty in city, regional, national, and international critical care conferences helps to fine-tune and update teaching approaches that can then enhance the scholarship of teaching critical care at one's home institution.

Investigate Mechanisms and Management of Critical Illness

Clinical investigation of critical illness is essential for the continued growth of effective critical care. Indeed, one of the hallmarks of critical care in the last decade has been the large number of high-quality clinical studies leading to better care. Yet the practice of critical care is often so demanding that the intensivist's time is consumed with providing state-of-the-art care. Accordingly, clinical investigation in the ICU requires an organized program that is parallel to and integrated with the practice and teaching of exemplary critical care. Such a program allows an outlet for the creative formulation of hypotheses arising at the bedside of critically ill patients. It also enhances the morale of the critical care physician–nurse–respiratory therapist team by developing shared confidence that new concepts are being regularly learned during delivery of critical care.

An effective critical care research team consists of a research director, critical care nurse research coordinator, and several critical care fellows. Regular scheduled communications about ongoing research protocols, their significance, and their need for patient recruitment need to be maintained between the research team and the critical care team. The research team needs to meet on a regular basis to interpret and update data in each of its protocols, and to consider and discuss new hypotheses for testing. Ideally, the clinical investigation of critical illness should interface with a basic science research program to allow bench or animal extensions of hypotheses that are difficult to test in the intensive care environment. Together the basic and clinical investigative teams implement the essential steps in clinical research in critically ill patients: formulate a hypothesis, prepare a protocol, obtain institutional review board approval, obtain funding, perform the study, and communicate the results.9

Many challenges exist in conducting studies in the environment of the ICU. These include the unpredictable and unscheduled nature of events, the need to maintain complex schedules related to routine care in parallel with schedules for study protocols, and the very heterogeneous nature of patient populations. In the view of many, the greatest challenge is conducting studies of promising therapies for which the precise risks and benefits are unknown, yet doing so in patients in whom informed consent is not possible because of their critical illness. Some would say that such studies simply cannot be done without consent, but we find this an undesirable acceptance of the current state of our ignorance. We believe that true equipoise exists in the interface between many clinical problems and their potential treatments (i.e., a realization on the one hand that our understanding of an existing treatment for a disease process is inadequate, yet no secure knowledge that a new approach or therapy is completely safe and efficacious).10 In this circumstance we believe that prospective, randomized trials offer the only hope of informing our practice of medicine, and that studies in the ICU, even if conducted with proxy or under some circumstances waived consent, are justified. The function of the institutional review board is to foster careful deliberation of the merits of each situation and proposed study to ensure that these balances are struck.