For most individuals, the highest priority is the capacity to live a life consistent with their needs and wants according to their sociocultural norms. The World Health Organization (WHO) acknowledges this in its International Classification of Functioning, Disability and Health, which emphasizes the interrelationship among structure and function, activity, and participation in life. Health has been defined by WHO as emotional, spiritual, intellectual, and physical well-being—not merely the absence of pathology.¹ Participation refers to the capacity of individuals to fulfill these needs in a social context and thereby fulfill the multiple roles in their lives—as parent, child, sibling, employee, employer, student, or homemaker, as well as in avocational pursuits (Figure 17-1). Participation in life is assessed by open-ended questions asked during the history and interview. In addition, an increasing number of questionnaire tools and scales are available for clinical use. Table 17-1 outlines some common generic and condition-specific tools that can be used to assess quality of life, life satisfaction, sickness impact, and subjective sense of well-being. These can be useful outcome measures (technically, these scales provide scores that are indexes rather than actual measures of the constructs) for the physical therapist and the patient. Many of these scales have been shown to be reliable as well as valid. Validating these scales is conceptually and methodologically challenging; hence their limitations must be recognized.

What Is the Problem?

Consistent with the International Classification of Functioning, Disability and Health, there are three primary levels of analysis:²¹

These components are affected by facilitating factors and barriers (see Figure 17-1).²¹ Structure and function refer to the underlying anatomic and physiological limitations that may or may not contribute to the patient’s symptoms but are clinically important and warrant remediation or being addressed in management. Limitation of activities contributes to a compromised capacity to fulfill one’s roles in life, such as those of occupation, profession, parent, and member of various groups that make up an individual’s identity. Usually, a patient presents clinically with complaints of being unable to complete tasks or fulfill roles because of pathophysiological, psychological, or environmental and physical barriers and limitations.

Measures and tools are standardized (concerning validity and reliability, see Chapter 7) for the assessment of each of these levels. With an increased focus on the quality of participation in life, numerous scales have emerged to quantify the subjective sense of well-being and health-related quality of life (see Table 17-1 for some examples).

Oxygen transport is determined by a multitude of factors that affect the steps in the oxygen transport pathway, thereby affecting participation in life and related activities (see Figure 17-1; see Chapter 2).^22–24 For intervention to be directed specifically to the underlying problems, the physical therapist needs to consider several levels of analysis of the deficits contributing to impaired or threatened oxygen transport. To be proficient in such analysis, the physical therapist must have a thorough knowledge of the multiple factors that contribute to normal gas exchange and those that contribute to abnormal gas exchange. This knowledge base includes a thorough understanding of the relevant anatomy and physiology; the multisystem and integrative pathophysiology; the impact of medical, surgical, and nursing procedures; the effects of various laboratory tests and procedures; and the impact of pharmacological agents on cardiovascular and pulmonary function (Box 17-1). Assessment of oxygen transport reserve and reserve capacity is fundamental to the management of all patients²⁵ and their risk factors,²⁶ regardless of disease acuity. Routine procedures contribute to fluctuations in oxygen demands.²⁷ Maximizing the ratio of oxygen delivery to consumption improves clinical outcomes in patients who range from being medically stable to being unstable.^28,29,30

For a given patient, the cardiovascular and pulmonary physical therapist prescribes intervention by extracting the relevant information from the history, the laboratory tests and investigative procedures, and the assessment (Box 17-2; see Part II). Although physical therapists are primarily noninvasive practitioners, they use and request the results of invasive tests and investigations in their assessments and evaluations. Problems are prioritized on the basis of the relative magnitude of each problem’s threat or effect on oxygen transport limitation, along with the evidence supporting the effectiveness of various noninvasive interventions in addressing each diagnosis or problem. Once the mechanisms of the cardiovascular and pulmonary dysfunction have been identified, specific interventions are selected and prioritized and the prescriptive parameters of each intervention are then defined. With respect to education, a learning assessment is an essential component of the overall assessment; it identifies health status knowledge deficits and prescribes learning interventions consistent with the patient’s needs (see Chapter 28).

Threatened Oxygen Transport

Although the complications of restricted mobility and static body positions are well understood, the precise prescription parameters for mobilization and body positioning to avoid these complications have not been defined in detail (see Chapters 18, 19, and 20). With respect to cardiovascular and pulmonary complications, a 1- or 2-hourly turning regimen is commonly accepted. For the patient who is flaccid or comatose, range-of-motion (ROM) exercises every several hours facilitates blood flow through dependent areas and enhances alveolar ventilation, as well as mobilizing joints and muscles. Antiembolic stockings and pneumatic compression devices are routinely used to minimize circulatory stasis in the legs and thereby the potential for thrombi formation.

The physical therapist has a major role in preventing infection of all types but particularly cardiovascular and pulmonary infections. Cardiovascular and pulmonary assessment and intervention involve handling and close contact with patients. Thus the risk for nosocomial infection is high in patients who are hospitalized. Some standard means of preventing infection include meticulous handwashing before and after visiting each patient, avoiding contact with open wounds and body fluids, and using clean technique in proximity to invasive lines and catheters. The physical therapist moves and repositions patients often, so it is essential that the positions of lines, leads, and catheters be continuously monitored to avoid displacement. The physical therapist must consider when it is appropriate to gown, mask, and use gloves so as to protect and be protected from the patient adequately.

Factors That Contribute to or Threaten Oxygen Transport

The factors that can impair oxygen transport directly or can threaten it fall into four primary categories (Table 17-4): the underlying cardiovascular and pulmonary pathophysiology, restricted mobility (loss of physical exercise stress), recumbency (loss of vertical gravitational stress), extrinsic factors (i.e., factors related to the patient’s care), and intrinsic factors (i.e., factors related to the patient).

Restricted Mobility and Recumbency

Although bed rest can be considered an extrinsic factor (i.e., a therapeutic intervention that contributes to cardiovascular and pulmonary dysfunction), the negative consequences of this intervention are often not appreciated fully because of the widespread use of rest in bed. To emphasize the importance of considering the effects of this intervention with each patient, the effects of restricted mobility and recumbency are analyzed separately (see Chapters 18, 19, and 20).

Intervention Goals

Once the deficits and threats to oxygen transport have been determined by the physical therapist, the goals of intervention fall into three categories: short-term, long-term, and preventive (Table 17-5). In addition to improving the outcomes of primary physical therapy interventions, physical therapists seek to eliminate, reduce, or delay the need for invasive care (i.e., drugs and surgery) as much as possible. These are core contemporary physical therapy goals.

Practice Patterns

The American Physical Therapy Association’s (APTA’s) Guide to Physical Therapist Practice (2003)³¹ has evolved over the past couple of decades, and it currently reflects a broad scope of practice. The Guide describes examination (history, systems review, and tests and measures), evaluation, diagnosis, prognosis (including plan of care), and intervention (with anticipated goals and expected outcomes). Each physical therapy area of practice has multiple associated practice patterns. Each practice pattern addresses reexamination, global outcomes, and criteria for termination of physical therapy services. Given the APTA’s adoption of the International Classification of Functioning, Disability and Health,²¹ the evaluation consists of a review of health rather than strictly a primary focus on illness. The iterative cycle of clinical decision making based on outcomes and the modification of interventions is designed to achieve the expected outcomes within a prescribed time frame (Figure 17-2). Based on the consensus of several hundred clinicians in the United States, several primary practice patterns have been defined for each specialty. Once patients are evaluated, their profiles may be described by one or more practice patterns, within one or more specialty areas of practice. There are eight practice patterns in the cardiovascular and pulmonary area (Box 17-3). These patterns and the Guide (2003)³¹ provide an overall frame of reference for practice rather than serving as a basis for practice. Patients are increasingly complex, given increasing life expectancy and concomitant comorbidities, coupled with lifestyle-related factors and their impact on the patient’s presenting complaint or underlying risk factors. Therefore categorizing a patient in one or more practice patterns may be insufficient to address the patient’s complaints. These patterns serve as guides only. They are not diagnoses, nor do they replace sound clinical reasoning and judgment.

The basis for clinical decision making in the management of the patient with cardiovascular and pulmonary dysfunction or its risk is to pair the most effective interventions with impaired or threatened steps in the oxygen transport pathway. Considerable time may pass between interventions, so a maximal therapeutic effect is dependent on the effectiveness of between-intervention interventions (i.e., teaching the patient to carry out prescriptive intervention whenever possible, motivating the patient to adhere to and follow the intervention plan, and eliciting the assistance of the patient’s family or nursing staff in supporting the patient in doing so).

When confined to hospital, patients may spend excessive time recumbent and in restricted body positions; they tend to turn and move less frequently and are not upright or moving much of time. Depending on the particular oxygen transport deficits of a patient, the body positions the patient assumes can have a positive, negative, or neutral effect on oxygen transport. Thus the patient’s position and his or her reduced activity level must be monitored and adverse effects anticipated, countered or, preferably, prevented.

Examples of some common intervention goals in managing the patient with cardiovascular and pulmonary dysfunction are shown in Box 17-4. Specific interventions are identified to address these goals and for each deficit or threat to oxygen transport. Intervention goals and specific interventions are prioritized according to the relative significance of the impact of each on oxygen transport.

Intervention Plan

The intervention plan consists of interventions that will most expediently and efficiently remediate the problems that have been identified. These interventions are prioritized according to the greatest effect they are predicted to have on remediating the oxygen transport deficit or minimizing any threat to oxygen transport and on maximizing their benefit-to-risk ratio given the specific patient’s presentation. Depending on the specific intervention goals and the adequacy of balance between oxygen supply and demand, the coordination of physical therapy interventions with other care (e.g., nursing care and certain tests and procedures) is commonly indicated.

Intervention Prescription

Once the specific pathophysiological problems underlying deficits or threats to oxygen transport have been identified, they are differentiated into (1) those that can be addressed by physical therapy (i.e., noninvasive physical interventions); (2) those that are not amenable to physical therapy but need to be considered during intervention to determine whether intervention is contraindicated or needs to be modified and whether specific outcome and intervention-response measures are indicated; and (3) those that are best managed invasively, which may necessitate referral to a physician.

Problems amenable to physical therapy are prioritized. Optimal interventions are identified for each problem, and their parameters are prescribed. The intervention goals are identified: to reverse pathophysiological mechanisms contributing to impaired oxygen transport: to compensate for irreversible pathophysiological deficits (improve the efficiency of other steps in the oxygen transport pathway); to decelerate deterioration; to avoid making the patient worse; to provide palliative care, support, and comfort; and to prevent the occurrence of problems in the future (see Intervention Goals, earlier in this chapter). Based on the goals of intervention, the parameters of the intervention are defined. Intervention parameters in the management of a patient with cardiovascular and pulmonary problems are shown in Box 17-5. To achieve these goals, a range of modalities and aids may be needed in the short term and in the long term (Box 17-6).

What Is the Course of Intervention?

Once an intervention has been prescribed, the prescription must be reviewed at each intervention session and modified accordingly (i.e., the prescription parameters change as the patient’s condition changes). In addition, the parameters may be modified within an intervention on the basis of the patient’s response. The physical therapist also decides when to discontinue a given intervention, as well as which cardiovascular and pulmonary physical therapy interventions to employ; again, these decisions are based on the patient’s responses to the intervention and on the outcome. Some change in intervention should be effected with one or two intervention sessions, confirming that improvement is being maximized. If no improvement is noted, an explanation is found and the intervention is changed to elicit improvement. When no improvement is demonstrated, particularly in patients who are seriously ill, physical therapy may still have a role in preventing deterioration, so it should not necessarily be withdrawn. However, a rationale should always be proposed for continued intervention in the event of no demonstrable change. Continued intervention may be indicated, for example, in a patient in an induced coma. Hemodynamic and oxygen transport status must be maintained in anticipation of the induced coma being reversed. In most other situations, however, some improvement toward the eventual goal of maximizing activity and participation status should be expected from every intervention.

Measures to assess response and outcome to interventions are selected so that they reflect (1) activity and participation status, (2) the status of oxygen transport overall, and (3) the integrity of the step or steps in the oxygen transport pathway that were identified as being the primary problems contributing to cardiovascular and/or pulmonary dysfunction in the original assessment (Table 17-7; see Part II). Cardiovascular and pulmonary dysfunction is determined on the basis of the history, assessment, and laboratory investigations such as pulmonary function testing, breathing pattern, cardiac function testing, fluid balance and renal function, arterial blood gases, arterial saturation, vital signs, and hemodynamic variables, including heart rate and ECG, blood pressure, and rate pressure product. Subjective reports are also clinically relevant, such as subjective ratings of perceived exertion, breathlessness, musculoskeletal or wound pain, angina, and fatigue. These same measures are used as outcome measures to detect improved oxygen transport and gas exchange.

Summary

This chapter provides a framework for clinical reasoning and decision making based on oxygen transport characteristics that underlie a limitation in activity and participation in life as defined by the model of ability advocated by the World Health Organization.²¹ Carried out in partnership with the patient, as much as possible, the process includes diagnoses and intervention prescriptions in the management of patients with cardiovascular and pulmonary dysfunction, who range from the individual who is medically unstable and critically ill to the individual who is medically stable with cardiovascular and pulmonary dysfunction, or its risk, and living in the community. The purpose of a systematic approach to clinical decision making is to maximize intervention outcome and cost effectiveness. This is done by focusing on physiological and evidence-based practice within the context of evidence-informed practice (i.e., informed by epidemiology) and monitoring to gauge improvement after every intervention so as to ensure that the patient is progressing and time is not wasted. The clinical decision-making process involves diagnosis (i.e., specific analysis of the patient’s problems—limitations in activity and participation) in relation to the physiology and underling pathophysiology, the contribution of restricted mobility and recumbency, and extrinsic (related to the patient’s care) and intrinsic (related to the patient’s characteristics) factors. Based on this analysis, interventions and their parameters are prescribed so that they have the greatest physiological and scientific justification for being likely to return an individual to health and participation in life. Interventions and their prescription parameters should have clear and justifiable rationales. Specific monitoring of the impaired steps in the oxygen transport pathway is essential to establishing and confirming the diagnoses, determining the potentially most effective interventions, evaluating the intervention response, refining and progressing the intervention, and determining when to discontinue intervention and physical therapy overall or to discharge the patient from care. The specific components of the intervention prescription include the intervention, its intensity (if applicable), duration, and frequency, as well as its course and progression. A problem-solving approach to patient care has become essential across health care professions, given the prohibitive cost of such care and the need for health care to be physiological, evidence-based, cost-effective, and ethically justifiable. As noninvasive practitioners, physical therapists need to evaluate their effectiveness in avoiding, reducing, or postponing the need for invasive care (i.e., drugs and surgery). Although these outcomes are exceptionally important, they all too often are underestimated in practice.