Dyspnea: Evaluation and Management

Transcription

1 Dyspnea: Evaluation and Management Sandra Whitlock, M.D. Four Seasons Palliative Care Course Handouts & Post Test o To download presentation handouts, click on the attachment icon o Presenter discloses no financial relationships with a commercial entity producing healthcare-related products and/or services. Conflict of interest disclosure and resolution statement is on file with HEN. o This presentation is for educational and informational purposes only. It is not intended to provide legal, technical or other professional services or advice. Objectives o Describe the physiological, psychological, social, and environmental factors contributing to dyspnea o Develop a differential diagnosis for dyspnea even in patients with end-stage disease o Identify possible treatments for a patient with dyspnea. 1

2 Suffering is experienced by persons, not bodies Dr. Eric Cassell Dyspnea is Subjective o Discomfort in breathing o Qualitatively distinct sensations that vary in intensity o Psychological experience is inseparable from the physical aspects of the symptom o May induce secondary physiological and behavioral responses ATS 1999; Am J Respir Crit Care Med 159: How is Dypsnea Diagnosed? o Gold standard is patient report. o Respiration rate, pulse oximetry, arterial blood gases are not useful guidelines o Patients may be hypoxic, but not dyspneic or dyspneic, but not hypoxic Hypercapnia is a more potent stimulus for dyspnea than hypoxia 2

3 Breathing Exercise Patients Use Different Descriptors When Characterizing Dyspnea o Air hunger o Tight/constricted o Heavy o Rapid o Shallow o Unrewarded o Increased effort o Suffocating o Huffing/puffing J Pain and Symptom Management 2002;23(3):183 The Pathophysiology of Dyspnea is Not Well Understood o Not as well characterized as other symptoms, such as pain or nausea o Sensation of dyspnea seems to originate with the activation of sensory systems involved with respiration o Much of our understanding stems from studies in healthy subjects or patients with COPD 3

4 Different Receptors Modulate Dyspnea o Chemoreceptors: Central: hypercapnia Peripheral: hypoxemia o Irritant receptors: Airways: inflammation, airway tone Alveloar C fibers: fluid and tissue damage o Mechanoreceptors: afferent mismatch Central Chemoreceptors (CO2) Cognitive/ emotional factors Peripheral Chemoreceptors (O2) RESPIRATORY CENTER = MEDULLA Pulmonary Vagal Afferents Stretch Irritant Alveloar C-fibers DIAPHRAGM ACCESSORY MUSCLES Mechanoreceptors: Diaphragm Intercostals Accessory Muscles Anxiety Worsens the Sensation of Dyspnea DYSPNEA ANXIETY 4

5 Cycle of Deconditioning Disease Dyspnea Reduced Activity Deconditioning Schwartzstein, MGH Palliative Care Grand Rounds 2008 Differential Diagnosis of Dyspnea o Pulmonary o Cardiovascular o Systemic Differential Diagnosis of Dyspnea o Pulmonary Bronchospasm Pleural effusion Airway mass/obstruction Lymphangitic spread Infection Pneumothorax Radiation injury 5

6 Differential Diagnosis of Dyspnea o Cardiovascular Pulmonary vascular disease (PE, pulmonary HTN) SVC syndrome Pericardial disease Pulmonary edema Ischemia Differential Diagnosis of Dyspnea o Systemic Afferent mismatch disorders of respiratory muscle weakness or mechanical disadvantage (ex. ascites, chest wall disease) Deconditioning Hypercarbia Hypoxia Anemia Anxiety Management of Dyspnea o Paucity of randomized controlled trials examining symptomatic interventions for dyspnea o Most importantly, the underlying cause should be identified and treated, if possible 6

7 Management of Dyspnea o Interventional Procedures o Non-pharmacologic Measures o Pharmacologic Measures Interventional Procedures o Pleural effusion: thoracentesis, pleural catheter, +/- pleurodesis o Ascites: paracentesis o Pericardial disease: pericardiocentesis/pericardial window o Obstructive mass: large airway stenting o Chemotherapy or cancer-related anemia: red blood cell transfusions o SVC syndrome: intravascular stenting Breathing techniques can be taught 7

8 Stimulation of V2 distribution decreases dyspnea sensation Cycle of Hypersensitization Disease Dyspnea Reduced Activity Anxiety with activity and change in ventilation Forgetfulness of normal hyperpnea Schwartzstein, MGH Palliative Care Grand Rounds

9 Nursing-led Rehab Programs o Breathlessness rehab techniques and coping with psychological aspects o Three trials looking at this intervention in cancer patients o Participants had much better performance status o Primary outcome assessed after weeks o All nursing-led interventions were beneficial, improving breathlessness and QoL Ben-Aharon et al. 2008; J Clin Onc, 26: Oxygen for Relief of Dyspnea o Abernathy et al. 2010: RCT, double-blind 239 patients, PaO2 > 7.3 KPa, life-limiting illness, refractory dyspnea Oxygen vs. compressed room air Outcome: subjective breathlessness by numeric scale (1-10) twice daily Findings: no significant difference between oxygen and compressed air Abernathy et al. Lancet 2010;376: Oxygen for Relief of Dyspnea o Hypoxia is only a weak stimulus for sensation of dyspnea o Perceived benefit even without hypoxia o Benefit likely from effect of stimulating V2 receptors o Routine O2 use not recommended in absence of hypoxia Thomas JR and von Gunten CF 2002; Lancet Oncol 3:

10 Pharmacologic Measures o Opioids o Benzodiazepines Pharmacologic Measures: Opioids o First-line therapy for symptomatic control of dyspnea o Mechanism of action is not well understood o Location of opioid receptors: Peripheral and central nervous system Tracheobronchial tree, highest concentrations in alveolar walls Mechanism of Action of Opioids o Dose-dependent reduction in minute ventilation increased pco2, but also decreased ventilatory response to CO2 o Modulation of perception of anxiety o Activation of peripheral opioid lung receptors inhibits acetylcholine release which leads to decreased bronchial constriction and mucus secretion. 10

11 Multiple Studies Support Opioid Use for Dyspnea o Bruera 1993 and Mazocatto 1999: SQ morphine vs. placebo RCT, crossover, double-blind 9-10 patients per study with primary lung cancer or lung metastases Outcome: subjective intensity of dyspnea by mean change in VAS after 45 min Findings: significant decrease in VAS measured 45 min after intervention Bruera et al. 1993; Ann Int Med 119: / Mazocato et al. 1999; Ann Oncol 10: Sustained Release Morphine Improves Dyspnea o Abernathy et al. 2003: RCT, crossover, double-blind 48 patients, primarily COPD w/ continued dyspnea despite optimal treatment 20mg SR morphine qday vs. placebo Outcome: subjective intensity of dyspnea by mean change in VAS on days 4 and 8 Findings: 5-10% decrease in VAS with morphine Abernathy et al. 2003; BMJ 327: Nebulized Morphine o Davis 1996 and Grimbert 2004: nebulized morphine vs. placebo Study design: RCT, double blind study Primary lung cancer or lung metastases Duration: 2 days Primary outcome: Davis: change in VAS rating of SOB after 60min Grimbert: subjective intensity of SOB after 48hr Intervention effect: none Davis et al. 1996; Palliat Med 10:64-65 Grimbert et al. 2004; Rev Mal Respir 21:

12 Nebulized Morphine Bruera 2005: SQ vs. nebulized morphine Study design: RCT, double blind study 12 cancer patients(lung, GI, other) Duration: 2 days Primary outcome: subjective intensity of dyspnea based on VAS score at 60min Intervention effect: no significant difference in dyspnea intensity, but more patients preferred nebulized morphine Bruera et al. 2005; J Pain Symptom Manage 29: Opioids are Safe and Effective o Jennings 2002: systematic review of opioids in management of dyspnea 11 of 18 studies cited reported on O2 and CO2 levels No change with initiation of opioids o More recent studies have shown no evidence of respiratory compromise when morphine or hydromorphone are used for breathlessness Jennings 2002; Thorax 57: Opioid Dosing o All opioids are considered to be equally efficacious in treating dyspnea o Doses needed to relieve dyspnea often less than those needed for relief of pain o Opioid half-life for relief of dyspnea is about 4 hours, but can be redosed every 1-2 hours as needed o Chronic opioids: increase basal dose by 25-50% to treat dyspnea Thomas JR and von Gunten CF 2002; Lancet Oncol 3:

13 Opioid Dosing o Treatment of dyspnea in the opioid-naïve patient: Morphine 5mg PO q4 Oxycodone 5mg PO q4 Hydromorphone 1mg PO q4 o For breakthrough, give an equivalent dose every 1-2 hrs as needed o Once 24-hour opioid requirement in determined, can change to long-acting o Titrate in increments of % q24hrs Thomas JR and von Gunten CF 2002; Lancet Oncol 3: Pharmacologic Measures: Anxiolytics o Sensation of dyspnea can induce anxiety that can worsen dyspnea DYSPNEA ANXIETY Limited Data to Support the Use of Anxiolytics in Dyspnea o Mitchell-Heggs et al. 1980: placebocontrolled study of four patients showed moderate doses of diazepam improved dyspnea o Several subsequent, small studies in healthy volunteers or COPD patients have shown no benefit of benzodiazepines over placebo Mitchell-Heggs et al. 1980; QJM 193:9-20 Thomas JR and von Gunten CF 2002; Lancet Oncol 3:

14 Benzodiazepines as Adjuvants o Navigente 2006: compared SQ morphine to SQ midazolam Population: 101 patients with terminal cancer, life expectancy < 1 week Design: RCT, no blinding Primary Outcome: dyspnea at 24 hours Findings: Morphine nonsignificantly more effective than midazolam; combination significantly more effective than morphine or midazolam alone Navigente et al. J Pain Symptom Manage 31:38-47, 2006 Pharmacologic Measures: Anxiolytics o Can use long or short-acting agents o Scheduled or PRN o Possible regimens: Lorazepam 0.5-1mg PO q4-6 Diazepam 2.5-5mg PO q6-8 Clonazepam mg PO q12 Midazolam 0.5mg IV q15min (for emergent management) Thomas JR and von Gunten CF 2002; Lancet Oncol 3: Other Pharmacologic Measures o Glucocorticoids Bronchospasm Lymphangitic spread Radiation pneumonitis o Bronchodilators: Bronchospasm and cough o Anti-cholinergics Copious secretions Scopolamine patch, levsin, glycopyrrolate 14

15 Nebulized Furosemide o Unknown mechanism of action o May be more than one mechanism of action involved Inhanced pulmonary receptor activity Suppression of the pulmonary irritant activity vasodilation o Recent review of 42 trials o Only five measured dyspnea as an outcome Nebulized Furosemide o Moosavi et al. 2007: Double blind, RCT Healthy human subjects w/ induced dyspnea Inhaled doses of 40mg furosemide over 10-15min 13% reduction in air hunger (variable effect, largest was a 74% reduction Significant increase in urine output Moosavi et al 2007; Respir Physiol Neurobiol 156:1-8 Objectives o Describe the physiological, psychological, social, and environmental factors contributing to dyspnea o Develop a differential diagnosis for dyspnea even in patients with end-stage disease o Identify possible treatments for a patient with dyspnea. 15

16 Questions? Four Seasons Center of Excellence o Consulting Hospice, Palliative Care & Research o Palliative Care Immersion Course o Mentoring physicians, nurse practitioners and physician assistants Course Handouts & Post Test Thank you for viewing this course on the Hospice Education Network The Course evaluation and post test are available from your course catalog page To achieve credit for this course, close the video portion when completed and click on Start Test 16