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Rehabilitation Therapy in the Critical Care Patient
CHAPTER 145 • Rehabilitation Therapy in the Critical Care Patient
CHAPTER 145 REHABILITATION THERAPY IN THE CRITICAL CARE PATIENT Ann M. Caulfield,
VMD, CCRP, CVA
KEY POINTS • Rehabilitation therapy should be included in the treatment plan for most critically ill veterinary patients. • Rehabilitation therapy must be prescribed and performed by (or under the direct supervision of) a trained and experienced rehabilitation therapist. • Patients must be frequently assessed and treatment plans modified based on the current medical status of the patient. • A team approach involving the critical care patient’s primary care veterinarian, nursing staff, and rehabilitation therapist is of absolute necessity in ensuring safe and effective rehabilitation therapy for each patient.
Rehabilitation therapy is a new and rapidly expanding discipline in modern veterinary medicine. Rehabilitation recommendations for a variety of orthopedic and neurologic conditions are now considered standard of care. The veterinary critical care patient is less commonly considered a candidate for rehabilitation therapy. It is well documented that the human critical care patient may experience any number of debilitating multisystem comorbidities associated with serious illness, pharmacologic adverse effects, and especially immobility.1 These include, but are not limited to, neuromuscular disorders, atelectasis, ileus, malnutrition, protein wasting, and depression.2 In the human intensive care unit (ICU), physical therapists specializing in critical care are integral members of a multidisciplinary team working together to optimize outcomes in patient recovery.2,3 Veterinary critical care patients are surviving catastrophic injuries and disease thanks to dramatic advances in critical care medicine.
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BOX 145-1
Goals for Range-of-Motion Exercises
Maintain or improve pain-free range of motion Maintain or improve flexibility, extensibility, and strength of periarticular soft tissues Maintain or improve synovial fluid diffusion across the articulating surface Prevent joint contracture Improve blood and lymphatic flow Promote proprioceptive responses and facilitate neuromuscular reeducation
The critically ill small animal patient is equally at risk of many of the same comorbidities seen in the human counterpart. Incorporating an individualized rehabilitation therapy program into the critical care patient’s overall treatment plan will enhance the animal’s recovery by minimizing systemic complications associated with immobility, reducing adverse effects of some pharmacologic interventions, improving pain management, and mitigating stress and anxiety associated with ill health and hospitalization. The aim of this chapter is to introduce the concept of rehabilitation therapy for the veterinary critical care patient and discuss the benefits of some basic, easily implemented therapies. The intent is not to provide a “how to” on the details of carrying out a specific treatment but rather to educate the reader on the important role that a comprehensive rehabilitation therapy program has in improving the quality of patient care in the modern veterinary critical care unit. Critically ill patients are in a dynamic physiologic state, and each patient is unique in its pathologic conditions, temperament, and tolerance of therapeutic interventions. To optimize treatment outcomes and ensure the safety of the patient, the importance of a trained and experienced rehabilitation therapist working in close communication with the animal’s primary clinician cannot be overemphasized.
MUSCULOSKELETAL SYSTEM Range-of-Motion Exercise Critical care patients often have or quickly develop range-of-motion (ROM) limitations due to preexisting conditions such as osteoarthritis or orthopedic, neurologic, or soft tissue trauma or disease, or as a consequence of sustained disuse or immobilization.4,5 All joints have a given range through which they normally move. Movement may be passive, active assisted, or active. Normal ROM for any joint is influenced by a number of factors, including flexibility of the periarticular soft tissue structures (joint capsule, muscles, tendons, ligaments, and skin) as well as the structure and health of the joint itself. Limitations in normal joint ROM result from conditions affecting any of these structures. The goals for ROM exercises are provided in Box 145-1.5
Passive Range-of-Motion Exercise Passive range-of-motion (PROM) exercises are passive movements of a joint through its available range. PROM movement incorporates an external force to move the joint and therefore does not involve active muscle contraction.5 Performed regularly, PROM exercises may help prevent joint contracture as well as soft tissue shortening. PROM exercises can also maintain movement across fascial planes and augment lymphatic flow. PROM sessions should be incorporated early in the course of treatment for any animal that is unable or not permitted to actively move its joints on its own. Since PROM exercises do not involve active muscle contraction, they do not prevent muscle atrophy or increase muscle strength. Guidelines for safe,
BOX 145-2
Guidelines for Performing Passive Range-of-Motion Exercises and Stretching Safely and Effectively
Exercises should be performed in a calm, quiet environment with the animal resting in lateral recumbency. Patient comfort is of the highest priority. Movements should be slow and gentle and limited to the patient’s comfortable range. Overaggressive passive range-of-motion exercises result in pain, cause reflex inhibition, and may promote the formation of fibrous tissue around the joint. Care should be taken to avoid disturbing any peripheral intravenous or arterial lines, indwelling urinary catheters, or electrocardiograph leads or other monitoring equipment. Movement should be limited to a single joint by stabilizing with one hand placed proximal to the joint and producing movement with the opposite hand placed just distal to the joint. To minimize forces being applied, the hands should be placed close to the joint being moved.
effective administration of PROM exercises and stretching are listed in Box 145-2. Generally, PROM exercises are performed three to five times per day for all peripheral joints, including the digits. Each movement is repeated 10 to 15 times.
Active Assisted and Active Range-of-Motion Exercise Active assisted and active ROM exercises encourage movement of a joint through active muscle contraction. In active assisted ROM, the therapist initiates or guides joint movement as the animal participates with active muscle contraction. Active ROM movement achieves joint motion solely through the animal’s muscle contraction.5 Active assisted or active ROM exercises are ideal for animals that are beginning to transition from PROM or those that are weak but capable of independent joint movement. Like PROM exercises, active assisted and active ROM exercises help counter the effects of immobilization and disuse on joints and periarticular structures. However, because they involve active muscle contraction, they can increase muscle strength and even bone strength at the sites of muscle attachment. Active and active assisted ROM exercises improve proprioception and balance. By coordinating movement of the various muscle groups they also facilitate reeducation of normal movement patterns. There are a variety of active assisted and active ROM exercises that can be used in the appropriate critical care patient.
Therapeutic Exercise and the Importance of Early Mobilization In human ICU patients early-intervention mobilization and exercise improve function by increasing oxygenation, strength, and endurance.4,6 Early mobilization has been shown to reduce length of stay in the hospital and in the ICU in particular.7,8 Immobility in the human model has been associated with a number of physiologic changes, including rapid loss of muscle mass and transformation of skeletal muscle fibers resulting in reduced aerobic capacity. Loss of muscle strength was greatest during the first 7 days of immobilization, with as much as a 40% reduction in strength.1 Also contributing to loss of muscle mass and strength in the human critical care patient are the direct effects of hypercapnia, hypoxia, malnutrition, and hemodynamic instability.9 The most profound loss of muscle strength was seen in the elderly and, not surprisingly, the chronically ill (e.g. patients with congestive heart failure).4
CHAPTER 145 • Rehabilitation Therapy in the Critical Care Patient
Although there is a paucity of studies investigating the effects of early-intervention mobilization in veterinary critical care patients, it is reasonable to assume that its benefits extend to nonhuman patients. For the stable patient, early mobilization through assisted standing and/or facilitated walking should be a priority in the rehabilitation treatment plan.
Assisted Standing Standing requires sophisticated neuromuscular coordination. Standing, even if assisted with a sling or therapy ball, promotes muscular strength in both the supporting peripheral limb muscles and the core muscles. In addition, it improves circulation and respiratory function, stimulates proprioceptive input, and promotes neuromuscular reeducation.5 To be upright and standing often improves a recumbent animal’s sense of well-being and can reduce frustration and associated anxiety. Sessions should be short, with careful attention paid to the patient’s fatigue level as well as any vital parameters of special concern to that individual such as respiratory rate and effort. When the animal is in a normal standing position, an attempt can be made to introduce weight shifts by gently and slowly rocking the animal front to back and side to side. Standing weight shifts are an excellent way to stimulate balance and proprioception as well as promote limb and core muscle strength.
Walking (Assisted and Unassisted) Walking is one of the most important therapeutic exercises prescribed for a rehabilitation therapy patient, including those in the critical care unit.7 Common sense dictates that this be an activity reserved for stable patients with no medical conditions precluding such movement. Walking provides a controlled, low-impact form of active exercise that enhances muscle strength, benefits articular cartilage, and promotes connective tissue health while at the same time improving cardiac, lymphatic, and respiratory system functions. A basic walking program facilitates normal balance and proprioceptive function and enhances a patient’s emotional well-being. There are a variety of mobility aids designed to assist a patient in walking. They range from simple booties that can improve traction on a slippery surface to slings and therapy carts that an ambulatory but weak patient can use as a “walker.” Regardless of the level of assistance an individual patient may need, it is critical that the walks be kept to short sessions several times a day. Careful monitoring of the patient’s status immediately before, during, and after the walk is important to ensure that the patient is not showing signs of weakness, fatigue, or respiratory compromise. Walk lengths can gradually be increased on a regular basis as the patient shows signs of improvement. Individual exercises should be prescribed by a trained rehabilitation therapist working in collaboration with the critical care team. As always, careful assessment of the patient’s current medical status and degree of debilitation should be made before any therapy session.
Neuromuscular Electrical Stimulation and Transcutaneous Electrical Stimulation In human critical care medicine, complications from severe illness and immobilization frequently lead to debilitating and persistent neuromuscular abnormalities.7 These observations have led physical therapists to develop early intervention treatment programs for the human critical care patient. Once a patient is deemed physiologically stable, appropriate rehabilitation therapy is initiated. One modality used in patients at risk of developing muscle weakness is neuromuscular electrical stimulation. Neuromuscular electrical stimulation is easily adapted to the veterinary critical care patient at risk of muscle wasting. Additionally, other electrical current therapy, like transcutaneous electrical stimulation, can be used as an adjunct to pain management in the critical care animal patient.
Neuromuscular electrical stimulation Neuromuscular electrical stimulation (NMES) uses low-voltage electrical current transmitted through electrodes placed on the skin to stimulate passive muscle contraction.7 In some ways, NMES simulates repetitive contractions of mild exercise since NMES-stimulated muscles have increased blood flow, maximal force output, and force endurance.9,10 There is a difference, however, in the order of motor unit recruitment between a physiologically initiated and an electrically induced muscle contraction. Electrical stimulation recruits the larger, fast twitch muscle fibers before the smaller, slow twitch fibers. This is the opposite of the order in which physiologically initiated recruitment occurs.5,11 Clinically, this is important because fast twitch fibers fatigue more quickly than slow twitch fibers; therefore longer rest periods are required between contractions to prevent muscle fatigue in the patient.11 Another important clinical consideration when using NMES for preventing disuse atrophy and strengthening muscles is that electrically stimulated muscle contractions likely recruit different motor units within a muscle than those recruited during a normal physiologic contraction. To optimize muscle strengthening, it is best to combine NMES with physiologic contractions if the patient is capable of some low-level assisted or active assisted exercise.11
Transcutaneous electrical stimulation Transcutaneous electrical stimulation (TENS) uses electrical current to modulate pain, most likely by interfering with transmission of noxious stimuli along A-delta and unmyelinated C nerve fibers. TENS activates nonnociceptor A-beta fibers. When more A-beta fibers are activated than C fibers and A-delta fibers, pain sensation is diminished. TENS may also produce analgesia by stimulating the production and release of endogenous opioids.11
Massage Massage is a highly effective, underutilized treatment in the veterinary critical care patient. Medical massage is recognized in the human medical community for its success in treating muscle, nerve, and fascia disorders as well as disruptions in the normal neurophysiology of the enteric nervous system with consequential disturbances in gastrointestinal motility.12 Specific training in medical massage therapy is now part of the curricula of many physical therapy training programs and medical schools. The benefits of gentle and caring touch delivered by a trained therapist can be wide ranging, from direct effects of increasing blood and lymphatic flow, improving gastrointestinal motility, and reducing muscle spasm to the more indirect effects of stress and anxiety reduction. Massage can easily be incorporated into the treatment plan of nearly every critical care patient in stable condition. Massage is the manual application of pressure to the body though a variety of specific maneuvers such as effleurage (stroking), tapotement (tapping or percussion), vibration, friction, and pétrissage (kneading).13 Fundamentally, therapeutic massage works through direct mechanical effects on muscle fibers, connective tissue, and vessel walls and through neuromodulation of peripheral sensory nerve receptors that relay information to the spinal cord for further processing and projection to higher centers.14 Peripheral stimulation of autonomic nerve fibers within the fascia may modulate the high sympathetic tone that occurs in many animal patients experiencing pain, illness, and/or emotional distress.13,15 Sustained increased sympathetic tone results in a physiologically maladaptive “vicious cycle,” which is counterproductive to healing and contributes to increased morbidity, central hypersensitization, and chronic pain states.13 Therapeutic massage techniques can decrease heart rate and blood pressure, which supports the idea that, in these patients, stimulation of peripheral sensory receptors with vagal nerve affiliation can dial
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down abnormally high sympathetic tone and dial up the parasympathetic system (which is more conducive to healing). As a result, heart rate, blood pressure, and cortisol levels decrease, vessels vasodilate and muscles relax, gastrointestinal motility becomes more normalized, and, at least for a while, the animal may disassociate from its current distressed state and gain a healing advantage. In both human and animal ICU patients it is common to see alterations in gastrointestinal motility caused by immobility, adverse effects of some medications, stress, and pain.12 It is interesting to note that in many human ICU patients ileus, nausea, and constipation are frequently mitigated through the use of specific abdominal massage techniques that promote improved gastrointestinal motility by stimulating dermal and subdermal vagal afferent nerves as well as gastrointestinal mechanoreceptors.12,15 One of the great advantages of properly performed therapeutic massage is the relative safety and low incidence of adverse effects associated with its use, even in a critically ill patient. However, there are contraindications that should be considered. Massage is contraindicated in areas of active infection or acute inflammation, near a tumor, in cases of deep vein thrombosis or coagulopathies, in patients with unstable fractures, and of course in animals intolerant of this type of hands-on therapy.
RESPIRATORY SYSTEM Respiratory system disease and dysfunction are leading contributors to increased morbidity and mortality in both human and veterinary critical care patients. Immobility and prolonged recumbency, mechanical ventilation, pain from chest wall or abdominal surgery or trauma, and sedation and altered states of consciousness secondary to head trauma or seizures can all interfere with the normal respiratory pattern and potentially reduce chest wall and lung expansion.16 Often animals in pain adopt a characteristic rapid and shallow breathing pattern that reduces tidal volume and lung compliance. The end result can be hypoventilation, atelectasis, accumulation of respiratory secretions, and pneumonia. Hypoxemia secondary to hypoventilation, ventilation-perfusion mismatch, or even intrapulmonary shunting necessitates treatment, thus prolonging hospital stays and further compromising an already debilitated patient.16 Respiratory therapists manage these patients daily in the human ICU. Adaptations of the techniques of these professionals can be incorporated into the veterinary treatment model so that the critically ill animal patient is at reduced risk of developing serious respiratory complications while in the critical care unit. It must be remembered that patients with compromised respiratory systems are in a precarious position and can easily decompensate. The following sections provide an overview of some basic techniques that can improve pulmonary function by helping to eliminate secretions, expand lung volume and open atelectatic lung fields, improve oxygenation, and reduce the work of breathing.17 It is critical that the trained therapist work closely with the patient’s primary clinician and be fully knowledgeable about any and all disease processes and health concerns, medications, and treatments for that patient. Constant objective and subjective assessment and reassessment before, during, and after a therapy session is important.
Positioning Proper positioning can positively influence lung function and is an effective treatment for animals with lung disease or a treatment strategy to prevent pulmonary complications in immobile patients. Simply alternating from opposite sides and sternal recumbency every 2 to 4 hours can increase chest wall expansion and lung volume, prevent atelectasis, improve oxygenation and perfusion, prevent
respiratory secretions from settling in dependent lung lobes, and improve patient comfort.18 Regularly changing a recumbent patient’s body position holds benefits beyond the respiratory system that include reduced muscle and joint stiffness, improved skin perfusion, and reduction in the formation of pressure sores, as well as prevention of dependent limb edema.17
Postural Drainage Retention of respiratory secretions interferes with proper oxygenation and ventilation. Postural drainage is a technique employed commonly by respiratory therapists treating human patients with pulmonary disease.18 It uses the force of gravity to aid in removing tracheal and bronchial secretions from a diseased lung segment by placing the patient into specific body positions. The patient is positioned so that the segmental bronchi are vertical to the diseased lung lobe.17 This positioning allows drainage of the secretions into the larger airways so that they are more easily expelled when a cough is elicited. Imaging studies are necessary to determine which lung segments are affected and therefore which positions should be used. It may be beneficial to nebulize the patient just before a treatment.5 Generally, the most affected lung segments are treated first and in the earlier part of the day. Treatment times range from 5 to 10 minutes in each position and treatments are performed several times a day. Following a treatment, the patient is encouraged to cough to aid in removal of the mobilized secretions.18 In animal patients, gentle digital pressure at the larynx or proximal trachea often elicits a cough. In some patients, it may take 30 to 60 minutes following a treatment for the secretions to be mobilized. There are certain patients in which postural drainage is contraindicated or should be approached with increased caution. Administration of supplemental oxygen before a treatment may be beneficial. In some patients, the standard postural drainage positions can actually worsen the animal’s condition. In these cases, postural drainage may not be an option or the standard drainage positions may need to be modified. Box 145-3 lists the conditions that may preclude the use of postural drainage as a treatment option. Postural drainage should be reserved for those patients that are immobile and have no contraindications to this treatment. Movement and exercise are superior to postural drainage in mobilizing respiratory secretions. Regular standing and walking should be used first in all patients that are capable of active mobility.
Percussion (Coupage) and Vibration Percussion and vibration are two chest rehabilitation techniques that can be quite effective in loosening bronchial secretions and then moving them from smaller to larger airways where they are more easily expelled via coughing.17,18 In percussion, the therapist uses cupped hands to gently tap over the diseased lung lobe in an even and steady rhythm. The cupping should produce a hollow tapping rather than a slapping sound and should be done between 100 and
BOX 145-3
Conditions That May Preclude the Use of Postural Drainage
Active pulmonary edema Congestive heart failure Severe obesity Increased intracranial pressure or head trauma Hemodynamic instability Recent cervical, cranial thoracic, or ocular surgery Vertebral body instability Patient intolerance of the procedure
BOX 145-4
Contraindications to the Use of Percussion and Vibration
Rib fractures, flail chest, or other thoracic trauma Coagulopathy Pneumothorax, pulmonary contusions, or other chest trauma Cervical or cranial thoracic subcutaneous emphysema Pulmonary embolism Frequent regurgitation Patient intolerance of the procedure
400 times per minute for 2 to 4 minutes. Percussion is done throughout the entire respiratory cycle. Vibration is performed following each percussion cycle and only during the exhalation phase of respiration. The therapist uses full hand contact on the animal’s chest to oscillate or shake the chest wall throughout the entire expiration. The hands should lie flat and remain placed over the area of diseased lung field. Vibration should be done during four to six consecutive exhalations following each set of percussions. Percussion and vibration are contraindicated in the conditions listed in Box 145-4.
SUMMARY Veterinary rehabilitation therapy offers highly effective, noninvasive treatment options for the unique subset of veterinary patients that are critically ill. Early intervention with comprehensive, individualized programs should be considered standard of care for every critical care patient.
REFERENCES 1. Genc A: Early mobilization of the critically ill patients: toward standardization, Crit Care Med 40(4):1346-1347, 2012.
2. Bemis-Dougherty AR, Smith JM: What follows survival of critical illness? Physical therapists’ management of patients with post-intensive care syndrome, Phys Ther 93:179-185, 2013. 3. Denely L, Bernay S: Physiotherapy in the intensive care unit, Phys Ther Rev 11(1):49-56, 2006. 4. Cirio S, Piaggi GS, DeMattia E, et al: Muscle retraining in ICU patients, Minerva Anestesiol 68(5):341-345, 2003. 5. Millis DL, Levine D, Taylor R: Canine rehabilitation and physical therapy, St Louis, 2004, Saunders. 6. Llano-Diez M, Renaud G, Anderson M, et al: Mechanisms underlying intensive care unit muscle wasting and effects of passive mechanical loading, Crit Care 16(5):R209, 2012. 7. Kress J: Clinical trials of early mobilization of critically ill patients, Crit Care Med 37(10):S442-S447, 2009. 8. Morris P, Goad A, Thompson C, et al: Early intensive care unit mobility therapy in the treatment of acute respiratory failure, Crit Care Med 36(8):2238-2243, 2008. 9. Needham DM: Mobilizing patients in the intensive care unit: improving neuromuscular weakness and physical function, JAMA 300:1685-1690, 2008. 10. Needham D, Trvong A, Fan E: Technology to enhance physical rehabilitation of critically ill patients, Crit Care Med 3(10):S436-S441, 2009. 11. Cameron M: Physical agents in rehabilitation: from research to practice, ed 2, St Louis, 2003, Saunders. 12. Robinson N: Acupuncture, massage can get the gut going, Vet Pract News, pp 36-38, February 2011. 13. Robinson N: Small animal manual therapy. In Proceedings Pennsylvania Veterinary Medical Association, 2012, pp 570-575. 14. Beck M: Theory and practice of therapeutic massage, ed 3, New York, 1999, Milady. 15. Tappan F: Healing massage techniques: holistic, classic, and emerging methods, ed 2, Norwalk, Conn, 1988, Appleton & Lange. 16. Powell L: Respiratory support for acute intensive care, NAVC Clin Brief, pp 13-16, April 2007. 17. Dunning D, Halling K, Ehrhart N: Rehabilitation of medical and acute care patients, Vet Clin North Am Small Anim Pract 35(6):1411-1426, 2005. 18. Davis LC: Personal communication, April 2012.
CHAPTER 145 REHABILITATION THERAPY IN THE CRITICAL CARE PATIENT Ann M. Caulfield,
VMD, CCRP, CVA
KEY POINTS • Rehabilitation therapy should be included in the treatment plan for most critically ill veterinary patients. • Rehabilitation therapy must be prescribed and performed by (or under the direct supervision of) a trained and experienced rehabilitation therapist. • Patients must be frequently assessed and treatment plans modified based on the current medical status of the patient. • A team approach involving the critical care patient’s primary care veterinarian, nursing staff, and rehabilitation therapist is of absolute necessity in ensuring safe and effective rehabilitation therapy for each patient.
Rehabilitation therapy is a new and rapidly expanding discipline in modern veterinary medicine. Rehabilitation recommendations for a variety of orthopedic and neurologic conditions are now considered standard of care. The veterinary critical care patient is less commonly considered a candidate for rehabilitation therapy. It is well documented that the human critical care patient may experience any number of debilitating multisystem comorbidities associated with serious illness, pharmacologic adverse effects, and especially immobility.1 These include, but are not limited to, neuromuscular disorders, atelectasis, ileus, malnutrition, protein wasting, and depression.2 In the human intensive care unit (ICU), physical therapists specializing in critical care are integral members of a multidisciplinary team working together to optimize outcomes in patient recovery.2,3 Veterinary critical care patients are surviving catastrophic injuries and disease thanks to dramatic advances in critical care medicine.
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BOX 145-1
Goals for Range-of-Motion Exercises
Maintain or improve pain-free range of motion Maintain or improve flexibility, extensibility, and strength of periarticular soft tissues Maintain or improve synovial fluid diffusion across the articulating surface Prevent joint contracture Improve blood and lymphatic flow Promote proprioceptive responses and facilitate neuromuscular reeducation
The critically ill small animal patient is equally at risk of many of the same comorbidities seen in the human counterpart. Incorporating an individualized rehabilitation therapy program into the critical care patient’s overall treatment plan will enhance the animal’s recovery by minimizing systemic complications associated with immobility, reducing adverse effects of some pharmacologic interventions, improving pain management, and mitigating stress and anxiety associated with ill health and hospitalization. The aim of this chapter is to introduce the concept of rehabilitation therapy for the veterinary critical care patient and discuss the benefits of some basic, easily implemented therapies. The intent is not to provide a “how to” on the details of carrying out a specific treatment but rather to educate the reader on the important role that a comprehensive rehabilitation therapy program has in improving the quality of patient care in the modern veterinary critical care unit. Critically ill patients are in a dynamic physiologic state, and each patient is unique in its pathologic conditions, temperament, and tolerance of therapeutic interventions. To optimize treatment outcomes and ensure the safety of the patient, the importance of a trained and experienced rehabilitation therapist working in close communication with the animal’s primary clinician cannot be overemphasized.
MUSCULOSKELETAL SYSTEM Range-of-Motion Exercise Critical care patients often have or quickly develop range-of-motion (ROM) limitations due to preexisting conditions such as osteoarthritis or orthopedic, neurologic, or soft tissue trauma or disease, or as a consequence of sustained disuse or immobilization.4,5 All joints have a given range through which they normally move. Movement may be passive, active assisted, or active. Normal ROM for any joint is influenced by a number of factors, including flexibility of the periarticular soft tissue structures (joint capsule, muscles, tendons, ligaments, and skin) as well as the structure and health of the joint itself. Limitations in normal joint ROM result from conditions affecting any of these structures. The goals for ROM exercises are provided in Box 145-1.5
Passive Range-of-Motion Exercise Passive range-of-motion (PROM) exercises are passive movements of a joint through its available range. PROM movement incorporates an external force to move the joint and therefore does not involve active muscle contraction.5 Performed regularly, PROM exercises may help prevent joint contracture as well as soft tissue shortening. PROM exercises can also maintain movement across fascial planes and augment lymphatic flow. PROM sessions should be incorporated early in the course of treatment for any animal that is unable or not permitted to actively move its joints on its own. Since PROM exercises do not involve active muscle contraction, they do not prevent muscle atrophy or increase muscle strength. Guidelines for safe,
BOX 145-2
Guidelines for Performing Passive Range-of-Motion Exercises and Stretching Safely and Effectively
Exercises should be performed in a calm, quiet environment with the animal resting in lateral recumbency. Patient comfort is of the highest priority. Movements should be slow and gentle and limited to the patient’s comfortable range. Overaggressive passive range-of-motion exercises result in pain, cause reflex inhibition, and may promote the formation of fibrous tissue around the joint. Care should be taken to avoid disturbing any peripheral intravenous or arterial lines, indwelling urinary catheters, or electrocardiograph leads or other monitoring equipment. Movement should be limited to a single joint by stabilizing with one hand placed proximal to the joint and producing movement with the opposite hand placed just distal to the joint. To minimize forces being applied, the hands should be placed close to the joint being moved.
effective administration of PROM exercises and stretching are listed in Box 145-2. Generally, PROM exercises are performed three to five times per day for all peripheral joints, including the digits. Each movement is repeated 10 to 15 times.
Active Assisted and Active Range-of-Motion Exercise Active assisted and active ROM exercises encourage movement of a joint through active muscle contraction. In active assisted ROM, the therapist initiates or guides joint movement as the animal participates with active muscle contraction. Active ROM movement achieves joint motion solely through the animal’s muscle contraction.5 Active assisted or active ROM exercises are ideal for animals that are beginning to transition from PROM or those that are weak but capable of independent joint movement. Like PROM exercises, active assisted and active ROM exercises help counter the effects of immobilization and disuse on joints and periarticular structures. However, because they involve active muscle contraction, they can increase muscle strength and even bone strength at the sites of muscle attachment. Active and active assisted ROM exercises improve proprioception and balance. By coordinating movement of the various muscle groups they also facilitate reeducation of normal movement patterns. There are a variety of active assisted and active ROM exercises that can be used in the appropriate critical care patient.
Therapeutic Exercise and the Importance of Early Mobilization In human ICU patients early-intervention mobilization and exercise improve function by increasing oxygenation, strength, and endurance.4,6 Early mobilization has been shown to reduce length of stay in the hospital and in the ICU in particular.7,8 Immobility in the human model has been associated with a number of physiologic changes, including rapid loss of muscle mass and transformation of skeletal muscle fibers resulting in reduced aerobic capacity. Loss of muscle strength was greatest during the first 7 days of immobilization, with as much as a 40% reduction in strength.1 Also contributing to loss of muscle mass and strength in the human critical care patient are the direct effects of hypercapnia, hypoxia, malnutrition, and hemodynamic instability.9 The most profound loss of muscle strength was seen in the elderly and, not surprisingly, the chronically ill (e.g. patients with congestive heart failure).4
CHAPTER 145 • Rehabilitation Therapy in the Critical Care Patient
Although there is a paucity of studies investigating the effects of early-intervention mobilization in veterinary critical care patients, it is reasonable to assume that its benefits extend to nonhuman patients. For the stable patient, early mobilization through assisted standing and/or facilitated walking should be a priority in the rehabilitation treatment plan.
Assisted Standing Standing requires sophisticated neuromuscular coordination. Standing, even if assisted with a sling or therapy ball, promotes muscular strength in both the supporting peripheral limb muscles and the core muscles. In addition, it improves circulation and respiratory function, stimulates proprioceptive input, and promotes neuromuscular reeducation.5 To be upright and standing often improves a recumbent animal’s sense of well-being and can reduce frustration and associated anxiety. Sessions should be short, with careful attention paid to the patient’s fatigue level as well as any vital parameters of special concern to that individual such as respiratory rate and effort. When the animal is in a normal standing position, an attempt can be made to introduce weight shifts by gently and slowly rocking the animal front to back and side to side. Standing weight shifts are an excellent way to stimulate balance and proprioception as well as promote limb and core muscle strength.
Walking (Assisted and Unassisted) Walking is one of the most important therapeutic exercises prescribed for a rehabilitation therapy patient, including those in the critical care unit.7 Common sense dictates that this be an activity reserved for stable patients with no medical conditions precluding such movement. Walking provides a controlled, low-impact form of active exercise that enhances muscle strength, benefits articular cartilage, and promotes connective tissue health while at the same time improving cardiac, lymphatic, and respiratory system functions. A basic walking program facilitates normal balance and proprioceptive function and enhances a patient’s emotional well-being. There are a variety of mobility aids designed to assist a patient in walking. They range from simple booties that can improve traction on a slippery surface to slings and therapy carts that an ambulatory but weak patient can use as a “walker.” Regardless of the level of assistance an individual patient may need, it is critical that the walks be kept to short sessions several times a day. Careful monitoring of the patient’s status immediately before, during, and after the walk is important to ensure that the patient is not showing signs of weakness, fatigue, or respiratory compromise. Walk lengths can gradually be increased on a regular basis as the patient shows signs of improvement. Individual exercises should be prescribed by a trained rehabilitation therapist working in collaboration with the critical care team. As always, careful assessment of the patient’s current medical status and degree of debilitation should be made before any therapy session.
Neuromuscular Electrical Stimulation and Transcutaneous Electrical Stimulation In human critical care medicine, complications from severe illness and immobilization frequently lead to debilitating and persistent neuromuscular abnormalities.7 These observations have led physical therapists to develop early intervention treatment programs for the human critical care patient. Once a patient is deemed physiologically stable, appropriate rehabilitation therapy is initiated. One modality used in patients at risk of developing muscle weakness is neuromuscular electrical stimulation. Neuromuscular electrical stimulation is easily adapted to the veterinary critical care patient at risk of muscle wasting. Additionally, other electrical current therapy, like transcutaneous electrical stimulation, can be used as an adjunct to pain management in the critical care animal patient.
Neuromuscular electrical stimulation Neuromuscular electrical stimulation (NMES) uses low-voltage electrical current transmitted through electrodes placed on the skin to stimulate passive muscle contraction.7 In some ways, NMES simulates repetitive contractions of mild exercise since NMES-stimulated muscles have increased blood flow, maximal force output, and force endurance.9,10 There is a difference, however, in the order of motor unit recruitment between a physiologically initiated and an electrically induced muscle contraction. Electrical stimulation recruits the larger, fast twitch muscle fibers before the smaller, slow twitch fibers. This is the opposite of the order in which physiologically initiated recruitment occurs.5,11 Clinically, this is important because fast twitch fibers fatigue more quickly than slow twitch fibers; therefore longer rest periods are required between contractions to prevent muscle fatigue in the patient.11 Another important clinical consideration when using NMES for preventing disuse atrophy and strengthening muscles is that electrically stimulated muscle contractions likely recruit different motor units within a muscle than those recruited during a normal physiologic contraction. To optimize muscle strengthening, it is best to combine NMES with physiologic contractions if the patient is capable of some low-level assisted or active assisted exercise.11
Transcutaneous electrical stimulation Transcutaneous electrical stimulation (TENS) uses electrical current to modulate pain, most likely by interfering with transmission of noxious stimuli along A-delta and unmyelinated C nerve fibers. TENS activates nonnociceptor A-beta fibers. When more A-beta fibers are activated than C fibers and A-delta fibers, pain sensation is diminished. TENS may also produce analgesia by stimulating the production and release of endogenous opioids.11
Massage Massage is a highly effective, underutilized treatment in the veterinary critical care patient. Medical massage is recognized in the human medical community for its success in treating muscle, nerve, and fascia disorders as well as disruptions in the normal neurophysiology of the enteric nervous system with consequential disturbances in gastrointestinal motility.12 Specific training in medical massage therapy is now part of the curricula of many physical therapy training programs and medical schools. The benefits of gentle and caring touch delivered by a trained therapist can be wide ranging, from direct effects of increasing blood and lymphatic flow, improving gastrointestinal motility, and reducing muscle spasm to the more indirect effects of stress and anxiety reduction. Massage can easily be incorporated into the treatment plan of nearly every critical care patient in stable condition. Massage is the manual application of pressure to the body though a variety of specific maneuvers such as effleurage (stroking), tapotement (tapping or percussion), vibration, friction, and pétrissage (kneading).13 Fundamentally, therapeutic massage works through direct mechanical effects on muscle fibers, connective tissue, and vessel walls and through neuromodulation of peripheral sensory nerve receptors that relay information to the spinal cord for further processing and projection to higher centers.14 Peripheral stimulation of autonomic nerve fibers within the fascia may modulate the high sympathetic tone that occurs in many animal patients experiencing pain, illness, and/or emotional distress.13,15 Sustained increased sympathetic tone results in a physiologically maladaptive “vicious cycle,” which is counterproductive to healing and contributes to increased morbidity, central hypersensitization, and chronic pain states.13 Therapeutic massage techniques can decrease heart rate and blood pressure, which supports the idea that, in these patients, stimulation of peripheral sensory receptors with vagal nerve affiliation can dial
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down abnormally high sympathetic tone and dial up the parasympathetic system (which is more conducive to healing). As a result, heart rate, blood pressure, and cortisol levels decrease, vessels vasodilate and muscles relax, gastrointestinal motility becomes more normalized, and, at least for a while, the animal may disassociate from its current distressed state and gain a healing advantage. In both human and animal ICU patients it is common to see alterations in gastrointestinal motility caused by immobility, adverse effects of some medications, stress, and pain.12 It is interesting to note that in many human ICU patients ileus, nausea, and constipation are frequently mitigated through the use of specific abdominal massage techniques that promote improved gastrointestinal motility by stimulating dermal and subdermal vagal afferent nerves as well as gastrointestinal mechanoreceptors.12,15 One of the great advantages of properly performed therapeutic massage is the relative safety and low incidence of adverse effects associated with its use, even in a critically ill patient. However, there are contraindications that should be considered. Massage is contraindicated in areas of active infection or acute inflammation, near a tumor, in cases of deep vein thrombosis or coagulopathies, in patients with unstable fractures, and of course in animals intolerant of this type of hands-on therapy.
RESPIRATORY SYSTEM Respiratory system disease and dysfunction are leading contributors to increased morbidity and mortality in both human and veterinary critical care patients. Immobility and prolonged recumbency, mechanical ventilation, pain from chest wall or abdominal surgery or trauma, and sedation and altered states of consciousness secondary to head trauma or seizures can all interfere with the normal respiratory pattern and potentially reduce chest wall and lung expansion.16 Often animals in pain adopt a characteristic rapid and shallow breathing pattern that reduces tidal volume and lung compliance. The end result can be hypoventilation, atelectasis, accumulation of respiratory secretions, and pneumonia. Hypoxemia secondary to hypoventilation, ventilation-perfusion mismatch, or even intrapulmonary shunting necessitates treatment, thus prolonging hospital stays and further compromising an already debilitated patient.16 Respiratory therapists manage these patients daily in the human ICU. Adaptations of the techniques of these professionals can be incorporated into the veterinary treatment model so that the critically ill animal patient is at reduced risk of developing serious respiratory complications while in the critical care unit. It must be remembered that patients with compromised respiratory systems are in a precarious position and can easily decompensate. The following sections provide an overview of some basic techniques that can improve pulmonary function by helping to eliminate secretions, expand lung volume and open atelectatic lung fields, improve oxygenation, and reduce the work of breathing.17 It is critical that the trained therapist work closely with the patient’s primary clinician and be fully knowledgeable about any and all disease processes and health concerns, medications, and treatments for that patient. Constant objective and subjective assessment and reassessment before, during, and after a therapy session is important.
Positioning Proper positioning can positively influence lung function and is an effective treatment for animals with lung disease or a treatment strategy to prevent pulmonary complications in immobile patients. Simply alternating from opposite sides and sternal recumbency every 2 to 4 hours can increase chest wall expansion and lung volume, prevent atelectasis, improve oxygenation and perfusion, prevent
respiratory secretions from settling in dependent lung lobes, and improve patient comfort.18 Regularly changing a recumbent patient’s body position holds benefits beyond the respiratory system that include reduced muscle and joint stiffness, improved skin perfusion, and reduction in the formation of pressure sores, as well as prevention of dependent limb edema.17
Postural Drainage Retention of respiratory secretions interferes with proper oxygenation and ventilation. Postural drainage is a technique employed commonly by respiratory therapists treating human patients with pulmonary disease.18 It uses the force of gravity to aid in removing tracheal and bronchial secretions from a diseased lung segment by placing the patient into specific body positions. The patient is positioned so that the segmental bronchi are vertical to the diseased lung lobe.17 This positioning allows drainage of the secretions into the larger airways so that they are more easily expelled when a cough is elicited. Imaging studies are necessary to determine which lung segments are affected and therefore which positions should be used. It may be beneficial to nebulize the patient just before a treatment.5 Generally, the most affected lung segments are treated first and in the earlier part of the day. Treatment times range from 5 to 10 minutes in each position and treatments are performed several times a day. Following a treatment, the patient is encouraged to cough to aid in removal of the mobilized secretions.18 In animal patients, gentle digital pressure at the larynx or proximal trachea often elicits a cough. In some patients, it may take 30 to 60 minutes following a treatment for the secretions to be mobilized. There are certain patients in which postural drainage is contraindicated or should be approached with increased caution. Administration of supplemental oxygen before a treatment may be beneficial. In some patients, the standard postural drainage positions can actually worsen the animal’s condition. In these cases, postural drainage may not be an option or the standard drainage positions may need to be modified. Box 145-3 lists the conditions that may preclude the use of postural drainage as a treatment option. Postural drainage should be reserved for those patients that are immobile and have no contraindications to this treatment. Movement and exercise are superior to postural drainage in mobilizing respiratory secretions. Regular standing and walking should be used first in all patients that are capable of active mobility.
Percussion (Coupage) and Vibration Percussion and vibration are two chest rehabilitation techniques that can be quite effective in loosening bronchial secretions and then moving them from smaller to larger airways where they are more easily expelled via coughing.17,18 In percussion, the therapist uses cupped hands to gently tap over the diseased lung lobe in an even and steady rhythm. The cupping should produce a hollow tapping rather than a slapping sound and should be done between 100 and
BOX 145-3
Conditions That May Preclude the Use of Postural Drainage
Active pulmonary edema Congestive heart failure Severe obesity Increased intracranial pressure or head trauma Hemodynamic instability Recent cervical, cranial thoracic, or ocular surgery Vertebral body instability Patient intolerance of the procedure
BOX 145-4
Contraindications to the Use of Percussion and Vibration
Rib fractures, flail chest, or other thoracic trauma Coagulopathy Pneumothorax, pulmonary contusions, or other chest trauma Cervical or cranial thoracic subcutaneous emphysema Pulmonary embolism Frequent regurgitation Patient intolerance of the procedure
400 times per minute for 2 to 4 minutes. Percussion is done throughout the entire respiratory cycle. Vibration is performed following each percussion cycle and only during the exhalation phase of respiration. The therapist uses full hand contact on the animal’s chest to oscillate or shake the chest wall throughout the entire expiration. The hands should lie flat and remain placed over the area of diseased lung field. Vibration should be done during four to six consecutive exhalations following each set of percussions. Percussion and vibration are contraindicated in the conditions listed in Box 145-4.
SUMMARY Veterinary rehabilitation therapy offers highly effective, noninvasive treatment options for the unique subset of veterinary patients that are critically ill. Early intervention with comprehensive, individualized programs should be considered standard of care for every critical care patient.
REFERENCES 1. Genc A: Early mobilization of the critically ill patients: toward standardization, Crit Care Med 40(4):1346-1347, 2012.
2. Bemis-Dougherty AR, Smith JM: What follows survival of critical illness? Physical therapists’ management of patients with post-intensive care syndrome, Phys Ther 93:179-185, 2013. 3. Denely L, Bernay S: Physiotherapy in the intensive care unit, Phys Ther Rev 11(1):49-56, 2006. 4. Cirio S, Piaggi GS, DeMattia E, et al: Muscle retraining in ICU patients, Minerva Anestesiol 68(5):341-345, 2003. 5. Millis DL, Levine D, Taylor R: Canine rehabilitation and physical therapy, St Louis, 2004, Saunders. 6. Llano-Diez M, Renaud G, Anderson M, et al: Mechanisms underlying intensive care unit muscle wasting and effects of passive mechanical loading, Crit Care 16(5):R209, 2012. 7. Kress J: Clinical trials of early mobilization of critically ill patients, Crit Care Med 37(10):S442-S447, 2009. 8. Morris P, Goad A, Thompson C, et al: Early intensive care unit mobility therapy in the treatment of acute respiratory failure, Crit Care Med 36(8):2238-2243, 2008. 9. Needham DM: Mobilizing patients in the intensive care unit: improving neuromuscular weakness and physical function, JAMA 300:1685-1690, 2008. 10. Needham D, Trvong A, Fan E: Technology to enhance physical rehabilitation of critically ill patients, Crit Care Med 3(10):S436-S441, 2009. 11. Cameron M: Physical agents in rehabilitation: from research to practice, ed 2, St Louis, 2003, Saunders. 12. Robinson N: Acupuncture, massage can get the gut going, Vet Pract News, pp 36-38, February 2011. 13. Robinson N: Small animal manual therapy. In Proceedings Pennsylvania Veterinary Medical Association, 2012, pp 570-575. 14. Beck M: Theory and practice of therapeutic massage, ed 3, New York, 1999, Milady. 15. Tappan F: Healing massage techniques: holistic, classic, and emerging methods, ed 2, Norwalk, Conn, 1988, Appleton & Lange. 16. Powell L: Respiratory support for acute intensive care, NAVC Clin Brief, pp 13-16, April 2007. 17. Dunning D, Halling K, Ehrhart N: Rehabilitation of medical and acute care patients, Vet Clin North Am Small Anim Pract 35(6):1411-1426, 2005. 18. Davis LC: Personal communication, April 2012.