Comprehensive Management of Individuals in the Intensive Care Unit

Elizabeth Dean and Christiane Perme

Cardiovascular and pulmonary physical therapy in the intensive care unit (ICU) is a subspecialty within cardiovascular and pulmonary physical therapy. This chapter presents the principles of clinical and nonclinical aspects of patient management in this setting. An overview of the general goals of management and the rationale for prioritizing treatments according to a physiological hierarchy is described. End-of-life issues are also addressed.

The thrust toward evidence-based practice in health care and the development of conceptual bases for practice have had major implications for cardiovascular and pulmonary physical therapy in the ICU.1–4 Superior knowledge of cardiovascular and pulmonary physiology, pathophysiology, pharmacology, multisystem dysfunction and its medical management, and ICU equipment and changing technology is essential. Clinical decision making in the ICU and rational management of patients is based on a tripod approach: knowledge of the underlying pathophysiology and basis for general care; knowledge of the physiological and scientific evidence for treatment interventions; and clinical reasoning and decision making in prioritizing treatments, prescribing their parameters, and performing serial evaluation to assess outcomes and further modify treatment (Figure 33-1). High-quality care is a function of these three areas of knowledge and expertise. Evidence-based practice and excellent problem-solving ability will optimize outcomes⁵ and maximize the benefit-to-risk ratio of cardiovascular and pulmonary physical therapy interventions.

Fig. 33-1 Tripod approach to patient management.

Specialized Expertise of the Intensive Care Unit Physical Therapist

Effective clinical decision making and practice in the ICU demand specialized expertise and skill, including advanced, state-of-the-art knowledge in cardiovascular and pulmonary and multisystem physiology and pathophysiology and in medical, surgical, nursing, and pharmacological management (Box 33-1). Physical therapists in the ICU need to be first-rate diagnosticians and observers. Given the multitude of factors that contribute to impaired oxygen transport,⁶ the physical therapist needs to analyze these to define the patient’s specific oxygen transport deficits and problems. Optimizing oxygen delivery in the patient who is critically ill⁷ by exploiting noninvasive interventions is the priority.

Box 33-1 Specialized Expertise and Skill of the Intensive Care Unit Physical Therapist

Detailed, comprehensive knowledge of cardiopulmonary physiology and pathophysiology and pharmacology.

Thorough working knowledge of the monitoring systems routinely used in the intensive care unit (ICU) and an understanding of the interpretation of the output of these monitoring systems (e.g., electrocardiogram [ECG], arterial blood gases, fluid and electrolyte balance, hemodynamic monitoring, chest-tube drainage systems, intracranial pressure monitoring). This information is an integral component for assessing the underlying problems and selecting, prioritizing, and progressing or modifying treatment.

Extensive expertise in cardiopulmonary assessment and treatment prescription; general experience in medicine and surgery is recommended.

Detailed understanding of multisystem physiology and pathophysiology and the cardiopulmonary manifestations of systemic disease.

Ability to practice effectively under pressure and in congested, suboptimal working conditions.

Knowledge regarding all emergency procedures, including those for respiratory and cardiac arrest, equipment problems, and power failure.

Knowledge regarding the paging system used in the unit for being contacted as well as for contacting other team members when they are out of the unit or out of the hospital.

On-call service, 24 hours a day, 7 days a week, is a common practice and should be considered in units without this service.

Knowledge regarding the roles of all team members.

Sensitivity toward each patient’s psychosocial situation, culture, and values and promotion of active involvement of the patient and family in clinical decision making, whenever feasible.

Superior communication skills (e.g., ability to work cooperatively with other members of the ICU team [Figure 33-3] and give verbal presentations and discuss patients at rounds).

Fig. 33-3 Multidisciplinary rounds in the intensive care unit (ICU). Team work in the ICU is essential to facilitate communication and patient outcome. Note the presence of the nurse, respiratory therapist, pharmacist, social worker, physical therapist, and physician. *When indicated, add resistance muscle exercise with aids and devices such as weights, belts, leg press, and ergometer pedals; progression is based on safety considerations and anticipated therapeutic responses.

The role of the ICU physical therapist is to promote healing and recovery and to return the patient to the highest possible level of life participation and satisfaction. Therefore the physical therapist must be capable of processing considerable amounts of objective information quickly, interpreting this information, and integrating it to provide the basis for a treatment prescription (i.e., the specific selection, prioritization, and implementation of treatment interventions). The ability to integrate and interpret the vast amount of multiorgan system data is perhaps the single most important skill in ICU practice and treatment prescription. With these data the physical therapist identifies the indications for treatment, contraindications, and optimal timing of interventions. The condition of the patient in the ICU can change rapidly. The physical therapist works within narrow windows of opportunity to effect an optimal treatment response. Treatments are variable with respect to their intensity, duration, and frequency. The maximally beneficial outcome with the least risk to the patient is the objective of every treatment. Although principles of management may be the same, specific knowledge requirements will differ depending on the type of critical care setting (e.g., burn, coronary care, neurosurgery, spinal cord injury, and trauma). Alternatively, a community hospital with a small general ICU will have a cross section of patients that the physical therapist will need to manage.

Goals and General Basis of Management

The ultimate goals of cardiovascular and pulmonary physical therapy in the ICU include the following:

1. Return the patient to his or her premorbid functional level or a higher level if possible

2. Reduce complications, morbidity, premature mortality, and length of ICU and overall hospital stay

As precursors to achieving these goals, the immediate goals relate initially to maximizing oxygen transport, hence, cardiovascular and pulmonary function; and second to maximizing musculoskeletal and neurological function. In the ICU the physical therapist needs to recognize the implications of cardiovascular and pulmonary insufficiency on neuromuscular status and that apparent impairment of neuromuscular status is not necessarily indicative of neurological dysfunction. Rather, reduced cardiac output and blood pressure, hypoxemia, hypercapnia, and increased intracranial pressure (ICP) may be responsible for these changes indirectly. Musculoskeletal and neurological complications can become life-threatening and therefore need to be detected early and managed.

Key elements of the assessment of the patient in the ICU include risk factors for a suboptimal clinical outcome. In addition to age and comorbidity, risk factors include poor indices of PaO₂ with a high FIO₂, platelet count, cardiac index, blood urea nitrogen, creatinine, and renal function. Other risk factors include peritoneal dialysis or hemodialysis, continuous infusion of antidysrhythmic agents, base deficit, reduced consciousness, pain, and cardiac arrest. Thus patients with one or more of these risk factors, conditions and interventions, require close monitoring and management.

Many elements of the assessment of patients in the ICU are comparable to those for patients with acute conditions who are not critically ill but require respiratory support and mechanical ventilation (see Chapter 44). The primary difference is that for patients in the ICU the adequacy of the steps in the oxygen transport pathway are monitored closely, and the status and function of multiple organ systems are monitored in a serial (repeated at regular or judicious intervals) manner to observe trends over time so that treatment modifications can be titrated to the patient’s responses. Serial vital signs including pain and distress are recorded along with arousal and cognitive status, neuromuscular status, musculoskeletal status, and functional mobility. Assessment of functional mobility ranges from the smallest movement to walking (see Figure 33-2 and Box 33-4). Often it includes bed mobility, transfers to chair, and walking, which may require assistive devices. Related laboratory investigations are noted, including the electrocardiogram (ECG), radiographs, scans, blood work, blood sugar level, and fluid and electrolyte balance, and are followed closely to quickly detect improvement or deterioration so that treatment can be correspondingly modified.

Mechanical ventilation and its modes and parameters are described in Chapter 44. The ventilator settings including the fraction of inspired oxygen (FIO₂) are important indicators of changes in the patient’s status and therefore must be included in the assessment and recorded at each treatment. Similarly, changes in FIO₂ are important outcomes and indicators of treatment response. This information is used collectively in clinical decision making before, during, and after weaning from mechanical ventilation.

In patients who are medically stable, invasive mechanical ventilation is titrated judiciously to ensure that the patient is initiating breaths as much as possible, which facilitates weaning. Depending on the patient’s response to ventilation, however, sedation and neuromuscular blockade may be indicated. These interventions limit the patient’s capacity to cooperate fully with treatment. Breathing patterns imposed by the mode of mechanical ventilation influence venous return and aortic pressures ⁸; thus mobilization needs to be prescribed accordingly. Furthermore, weaning patients with chronic obstructive pulmonary disease (COPD) and neuromuscular conditions is complicated by respiratory muscle weakness and fatigue (see Chapter 26), which may indicate respiratory muscle training or rest. Because of these challenges, weaning necessitates close cooperation and coordination within the team to maximize weaning success.

As for patients who are not critically ill, the assessment data are evaluated, problems and diagnoses made, and interventions prescribed based on the patient’s needs and goals. Physical therapy has a prominent role in the management of patients who are on mechanical ventilation.9,10 With each treatment, the responses are reviewed and prescription parameters of the interventions are refined to progress the patient

Restricted Mobility and Recumbency

Hospitalization, particularly in the ICU, is associated with a considerable reduction in mobility (i.e., loss of exercise stimulus) and recumbency (i.e., loss of gravitational stimulus) (see Chapters 18 and 20).^11–13 These two factors are essential for normal oxygen transport; thus their removal has dire consequences for the patient with or without cardiovascular and pulmonary dysfunction.

In terms of a physiological hierarchy of treatment interventions (see Chapter 17), exploiting the physiological effects of acute mobilization, upright positioning, and their combination is the most physiologically justifiable primary intervention to maximize oxygen transport and prevent its impairment in patients who are critically ill.

Recumbency is nonphysiological; it is a position in which, all too often, most patients are injudiciously confined. Changing the position of the body from erect to supine positions results in significant physiological changes that may jeopardize the patient’s already compromised or threatened oxygen transport system (Box 33-2) (see Chapter 20).

Box 33-2 Physiological Changes When Changing from the Upright to the Supine Position

Cephalad displacement of the visceral contents and diaphragm

Compression of the dependent lung fields

Cephalad fluid shift to the central circulation

Increased stroke volume and cardiac output and over days a reduction caused by renal compensation

Decreased total lung capacity

Decreased vital capacity

Decreased functional residual capacity

Decreased residual volume

Decreased forced expiratory volumes

Increased airway resistance

Increased closing volumes of small airways

Increased restriction of chest wall and decreased diaphragmatic excursion

Decreased pulmonary and chest wall compliance

Decreased arterial oxygen levels

Decreased cough effectiveness

Increased preload, afterload, and myocardial work

Decreased myocardial efficiency

Decreased sympathetic stimulation and decreased peripheral vascular resistance

The culmination of these deleterious effects offsets the increased homogeneity of ventilation and perfusion and their matching in the supine position. These effects compound the superimposed factors of restricted mobility, recumbency-induced central fluid shifts, prolonged lying without the normal stimulation or will to turn the body, and underlying pathophysiology or trauma that may contribute to impaired cardiovascular and pulmonary function and oxygen transport. Theoretically, the more compromised the patient, the greater the priority to maximize time spent in the upright position in conjunction with exploiting the benefits of acute mobilization.

Specificity of Cardiovascular and Pulmonary Physical Therapy

Physical therapy interventions in the ICU (see Chapter 17 and Part III) are more specifically geared toward the status of each organ system, taking into consideration the pathophysiological basis for the patient’s signs and symptoms, the rationale for each intervention, and the physiological and scientific evidence supporting the effectiveness of the intervention.¹⁴ Physical therapy provides both prophylactic and therapeutic interventions for the patient in the ICU. Conservative, noninvasive measures constitute initial treatments of choice to avert or delay the need for additional invasive monitoring and treatment including supplemental oxygen, pharmacological agents, and the need for intubation and mechanical ventilation. The physical therapist aims to avoid, reduce, or postpone for as long as possible the need for respiratory support. Even if the patient is mechanically ventilated, maintaining some level of spontaneous breathing, no matter how minimal, is associated with improved oxygenation and outcomes.¹⁵ In addition, the physical therapist helps to prevent the multitude of side effects of restricted mobility and recumbency during bed rest. A summary of general information required before treatment of the patient in the ICU is presented in Box 33-3. This provides the basis for establishing a patient’s readiness to be mobilized and the progressive steps for doing so (Box 33-4 and Figure 33-2).

Box 33-3 General Information Required before Treatment of the Patient in the Intensive Care Unit