Dyspnea CBM and Oxford Flashcards
1
Q
What is dyspnea?
A
- subjective sensation
- uncomfortable awareness of breathing.
- Does not correlate with clinical or lab measurements
- Based on stimulation of neuropsychological pathways
- conscious perception of stimuli
- interpretation of symptom in context of prior life experiences
2
Q
Pathophysiology of dyspnea
A
- Stimulation of mechanoreceptors, chemoreceptors, vagal afferents
- impulses transmitted to sensory cortex and respiratory centre in medulla
- Signals sent to motor cortex and respiratory muscles AND within sensory cortex
- = conscious perception of shortness of breath
- Experience of breathlessness affected by:
- previous experiences
- meaning of breathlessness
- mismatch between ventilatory demand and body’s ability to respond
3
Q
Prevalence of dyspnea
A
- COPD 95%
- CHF 61%
- Stroke 37%
- ALS - 50%
- Dementia 70%
- Cancer 46-70%
Depends on underlying disease, comorbidities and stage of disease
4
Q
COPD Risk Factors (CBM)
A
- cigarette smoking (1 ppd- 15% risk of COPD, 2ppd 25% risk)
- passive cigarette exposure
- occupational exposure
- alpha anti trypsin deficiency
5
Q
What abnormalities might you see on a Chest Xray of a person with COPD?
What pulmonary functiont tests confirm the diagnosis?
A
- CXRAY:
- normal
- increase AP diameter of chest
- Hyperinflation
- flattening of diaphragm
- PFTs:
- FVC (lung volume)
- FEV1 (airflow obstruction)
- FEV1/FVC < 70% of the predicted value
- MODERATE COPD FEV1 >/ 50%
- SEVERE FEV1 35-49%
- VERY SEVERE FEV1 34 %
- FEV1 increases by 15% after bronchodilators = significant response
6
Q
What are the management goals in COPD?
A
- To improve symptoms by decreasing airflow obstruction and airway inflammation
- To prevent secondary complications like infection
- To maintain function
- To improve QOL
7
Q
What is the mechanism of action for B2 agonist and an anticholinergic? (CBM)
A
Beta2-agonists
- bronchodilation via stimulation of B2 adrenergic receptors in airways
- Used on as needed basis
- rapid onset, short half life
- SE: tachycardia, anxiety
Anticholingergics
- Bronchodilation via inhibiting cholingeric mediated bronchmotor tone
- inhibits vagally mediated bronchoconstrictions
- REgular initial therapy
- stronger bronchodilator effects, longer half life, fewer SE than B2 agonists
8
Q
Vaccination in COPD
A
- respiratory infection can precipitate airway inflammation - trigger COPDAE
- high risk of infection in COPD
- influenza: secondary bacterial pneumonia
- influenza: increased risk of MI, arrythmia, stroke (cytokines)
- vaccine efficacy 70% reduction in morbidity
- Streptococcus pneumonia : CAP
- pneumococcal vaccine q10 years.
9
Q
Pulmonary rehabilitation for COPD
A
- teaching correct inhaler technique
- breathing and relaxation
- energy conservation
- nutritional guidance
- exercise program
- breathing techniques:
- tripod breathing imrpoves efficiency by improving the length-tension dynamic of diaphragm
- pursed lip breathing slows RR, increases intra-airway pressures
- rehab programs outcomes:
- decrease breathlessness
- imrpoved exercise tolerance
- better QOL
10
Q
Home 02 in COPD
A
COPD patients with daytime hypoxia may have increased survival with 02.
- Continuous 02:
- Pa02 < 55 mmHg or 02 sat < 88% at rest
-
Pa02 56-59 mmHg or 02 sat 89% IF:
- polycythemia
- cor pulmonale
- pulmonary hypertension
- Intermittent 02:
- Pa02 <55 mmHg or 02 sat < 88% during exertion
- Pa02 < 55 mm Hg or 02 sat < 88% during sleep
11
Q
Malnutrition and COPD
A
- respiratory muscle wasting
- weakness
- Re-feeding, reconditiong, anabolic steriods
- pulmonary rehab
- Cachexia treatment
12
Q
What is the 1 year mortality of COPD patients with FEV1 < 1 L?
A
30%
(worse than many cancers)
13
Q
Superior Vena Cava Syndrome: clinical diagnosis
A
- clinical severity:
- degree of narrowing of SVC
- speed of onset
- adequacy of venous collaterals
- dyspnea
- facial, neck, arm swelling
- Facial plethora
- dilation and tortuostiy of veins of upper body
- cyanosis of face.
- orthopnea
- cough
- headaches
- stridor /hoarseness
- nasal congestion/rhinorrhea
- proptosis
- severe: cerebral edema
14
Q
SVC syndrome : diagnostic tests
A
- malignancy > 90% of cases
- NSCLC 50%
- SCLC 25%
- Lymphoma and metastatic lesions (breast most likely) 10%
- Thrombosis of SVC
- CT with contrast
- Tissue diagnosis if needed:
- peripheral biospy
- perc biopsy peripheral lung mass (75%)
- bronchoscopy (50-70% dx yield)
- mediatstinoscopy (90%)
- open lung biospy
15
Q
SVC syndrome : managment
A
- treat malignancy
- radiation
- chemotherapy
- SCLC = chemo fast
- elevate head of bed
- 02
- fan/02
- Dexamethasone 8mg po bid
- case reports only
- do not give BEFORE diagnosis: lymphomas highly sensitive to dex
- Diuretics NOT recommended:
- reduce preload, hypotension and shock, increased thrombosis
16
Q
What are the clinical findings of Airway Obstruction?
A
- tachypnea
- increased WOB, accessory muscle use
- tracheal deviation to IPSILATERAL side of collapse/obstruction
- IPSILATERAL no air entry
- IPSILATERAL absent tactile and vocal fremitus
17
Q
What treatment options exist if there is an endobronchial obstruction?
A
- external beam Radiation
- laser
- electrocautery
- cryotherapy
- endobronchial irradiation
- photodynamic therapy
- tracheobronchial stenting
18
Q
What are the clinical findings of Pleural Effusion?
A
- Tachypnea
- Accessory muscles
- Shallow breathing
- CONTRALATERAL tracheal deviation (fluid pushing it away)
- dulllness to percussion
- decreased tactile and vocal fremitus
19
Q
Pleural Effusion treatment
A
- Thoracentesis
- pleural fluids: cell count, cytology, LDH, protein, pH, culture and sens.
- > 1.5 L may cause pulmonary edema
- Chest tube to drainage:
- Pleurex indwelling catheter
- Pleurodesis:
- sclerosing agent talc to create inflammation
- pleura stick together
20
Q
Define lymphangitic carcinomatosis
A
- diffuse infiltration and obstruction of pulmonary parenchymal lymphatic channels by tumour
- Non specific interstitial pattern on CXRAY
- CXRay can be normal
- high resoluation CT
21
Q
Lymphangitic carcinomatosis : managment
A
- oncological treatment
- corticosteroids
- diuretics
- poor prognosticator
22
Q
Dyspnea: Opioids - mechanism of action
A
- Oral/parenteral opioids
- Jennings et al. 2001. Opioids for the palliation of breathlessness in terminal illness. Cochrane Database of Syst Review; Issue 4, CD002066.
- no benefit of nebulized opioids
-
Mechanism of action of opioids in dyspnea
- change perception of breathlessness
- decrease in 02 consumption
- fall in ventilatory drive
- reduced response to stimuli like hypoxia and hypercapnia
- Cochrane review: 02 and c02 levels did not change with introduction of opioids
- depends on tolerance, rate of dose increase, possiblly route of adminstration.
23
Q
Dyspnea management : oxygen in palliative care
A
- Oxygen
- hypoxia + dyspnea - clear evidence for 02 (survival benefit in copd)
- Not recommended for hypoxia NO dyspnea
- Non hypoxia + dyspnea = fan, humidifer, air by NP
- Non hypoxia + dyspnea = trial humidified 02 by NP if fan fails.
- Palliative 02 - 02 for symptom relief without hypoxia
- Advanced cancer - 02> air in some studies
- COPD no hypoxemia - individual basis
- Mixed diagnosis - no benefit of 02 over air
- CHF - no clear benefit
24
Q
Other medications for dyspnea? Phenothiazines
A
- Phenothiazines : second line agents
- Oral promethazine
- Methotrimeprazine (oral or subQ)
- Chlorpromazine (oral , IV)
- NOT Prochlorperazine (WHY?)
- No trials, clinical practice only
25
Q
Terminal respiratory secretions
A
- loss of ability to clear secretions
- pooling in oropharynx and bronchi
- Normal
- Reposition
- Gentle suctioning of oropharynx only
- No deep suctioning
- Anticholinergics (anti muscarinic)
- Hyoscine hydrobromide (scopolamine) - BBB –> delirium
- Glycopyrrolate –> less delirium
26
Q
Define 3 qualities of dyspnea
A
- Air hunger
- conscious perception of urge to breathe
- motor drive of respiratory centres in brainstem send signal to cerebral cortex
- If not matched with adequate ventilation from feedback from afferent receptors in resp system__> air hunger
- Work/effort
- uncomfortable sense of respiratory effort
- resp muscle afferents and perceived cortical motor demand
- Tightness
- bronchoconstriction
- pulmonary afferents through the stimulation of airway receptors
27
Q
Where on neuroimaging (PET, fMRI) is activated in dyspnea?
A
- R anterior insula
- Amygdala
28
Q
History and Physical for Dyspnea
A
- History:
- intensity
- quality (episodic, constant)
- associated distress
- impact on life
- concerns of patients and caregivers
- Physical
- Severe signs :
- stridor
- tachypnea
- tachycardia
- Resp distress
- ALOC
- Severe signs :
29
Q
Investigations in dyspneic patients
A
- hemoglobin
- 02 sat
- CXRay
- Rare abg
- PFTs
- Echo
- Doppler
- CT
30
Q
List three ways to measure dyspnea (American Thoracic Society)
A
- Sensory - perceptual experience
- rating of symptom intensity
- Affective distress
- Immediate distress or cognitive (long term) distress
- Symptom impact
- QOL
31
Q
List malignant and paramalignant causes of dyspnea and treatment
A
- Lung cancer - chemo, targeted therapy
- Metastatic disease to lung - chemo, etc
- Pleural effusion - thoracentesis, pleurodises, PleurX cath
- SVCO - Radiation, stents, chemotherapy, steroid
- PE- LMWH
- Pericardial effusion - pericardiocentesis, pericardiotomy
- Major airway obstruction - stent, radiation, steroids, cryotherapy, laser therapy
- Lymphangitic carcinomatosis - chemo, steroid
- Radiation induced pneumonitis - steroid
- Drug induced pneumonitis - steroid
- Chest infection (PNA, empyema) - antibiotics
Systemic malignant causes
- Cancer cachexia - prevent aspiration
- Ascites - paracentesis
- Hepatomegaly - prop up position
32
Q
List non malignant causes and treatment of dyspnea
A
- COPD - rehab, LABA, SABA, inhaled steroid, phosphodiesterase inhibitors
- Bronchiectasis - airway clearance, antibiotics
- Interstitial pulmonary fibrosis - steroids
- CHF - ACE, BB, hydralazine, nitrates, ARB, Spironolactone, digoxin, diuretics
- Arrythmias - antiarrythmics, cardioversion
Systemic causes
- Muscle weakness motor neuron disease - NIV
- ALS - NIV
- Muscular dystrophy - NIV
- Anemia - transfusion, iron, erythropoeitin
- Acidosis - Bicarb
- Deconditioning - exercise, rehab
- Panic attack - CBT, benzo
33
Q
Management of dyspnea - non pharmacological
A
Some good evidence
- Breathing training
- pursed lip breathing, diaphragmatic breathing, positioning, pacing
- Walking aids
- Neuromuscular electric stimulation
- Chest wall vibration
- Exercise
Some not so good evidence
- Handheld fan (Randomized cross over trial)
- Nurse follow up program
- Acupuncture
No good evidence
- relaxation
- music
- counselling
- psychotherapy
34
Q
Dyspnea- opioids - clinical indications, dosing
A
- best evidence for advanced cancer, COPD
- CHF - conflicting evidence
- Motor neuron disease, ILD - anecdotal reports only
- No evidence for nebulized opioids
- Starting dose variable
- Morphine SR 10 mg most studied
- Increase of 25% of patients already on opioids
- Fentanyl for incidental breathlessness
- Choose dose based on:
- renal function, hepatic function, frailty, resp failure
- usually lower dose for dyspnea than for pain
35
Q
List other medications for dyspnea?
A
- Benzodiazepines
- role for patients with anxiety + dyspnea
- Inhaled furosemide
- enhanced pulmonary receptor activity, suppression of pulmonary irritant and vasodilation
- may be useful for dyspnea in airway diseases (asthma, copd)
- no clear evidence for use in cancer
- Heliox
- low density, improves ventilation by replacing nitrogen
- works for lung cancer, COPD already responding to 02
- expensive and not available, limited clinical use
36
Q
Palliative use of Non Invasive Ventilation
A
- AECOPD with type 2 respiratory failure
- hypoxemic pulmonary edema
- hypoxemis respiratory failure
- advanced neuromusclar disorders (ALS)
- require advanced nursing skills
- can be burdensome
- OPtion for withdrawal anytime
37
Q
Cough : function
A
- Inspiratory phase: lengthening of expiratory muscles
- Compression phase : against closed glottis, build up of intrathoracid pressure.
- Expiratory phase : expel air at high velocity with compression of airway.
- Cough protects airway by clearing inhaled materials, mucus, sputum
- Effort is reduced:
- cachexia
- steroid myopathy
- gross ascites
- hepatomegaly
- altered LOC
- vocal cord paralysis
- tumour
- stent
- altered mucous or mucociliary action in COPD, CF, chronic smokers
38
Q
Regulation of Cough
A
- Modulated by vagal afferent pathways
- rapidly adapting receptors (RARs) : activated by smoke, hypertonic saline –> bronchoconstriction
- C fibres : capsaicin, bradykinin, acidity
- Cough receptor : touch, acid
- activation of vagal afferents depends on expression of ion channels:
- TRP vanilloid (TRPV1)
- capsaicin, acid, inflammatory mediators
- TRP anakyrin (TRPA1)
- cold, air pollution, cigarette smoke
- calcium permeable, non selective cationic channels
- TRP vanilloid (TRPV1)
- Afferent sensory nerves synapse in nucleus solitarus in brainstem
- Transmitted to cough centre –> coordinate cough reflex
39
Q
Causes of cough in palliative care
A
Cancer etiologies
- Airway tumours
- pleural involvement
- pericardium
- mediastinum
- lymphangitic carcinomatosis
- dysphagia
- aspiration
- hypersecretion of mucus
Non cancer causes:
- COPD
- Asthma
- bronchiectasis
- IPF
- upper airway cough syndrome
- GERD
- Smoking
40
Q
Assessment of cough in palliative care:
A
History:
- associated sputum
- precipitating factors: smoking irritants, drugs, feeding, posture, timing of the day
- Associated sx: dyspnea, insomnia, choking, fatigue
- cancer treatment
- ACE
- chronic cardiac or lung conditions
- validated scale for cough
Investigations (potential):
- lung function tests
- sputum culture
- CXray
- CT scan
- SLP swallowing assessment
41
Q
Management of cough : treatment for cancer related causes
A
- radiotherapy
- chemotherapy (gemcitabine especially)
- endobronchial therapy
- Steroids for tumour edema, airway obstruction, lymphangitic carcinomatosis, radiation, immune therapy pneumonitis
- Antibiotics with caution (resistance, ineffectiveness)
42
Q
Management of cough : non-cancer causes
A
- discontinue ACE
- Empiric treatment of common causes : AUC, rhinitis, GERD
- antihistamine
- decongestant
- PPI
- Bronchodilator
- Possible steroids
43
Q
Anti-tussive medications : centrally acting
A
- Centrally acting - opioids u receptors CNS
- Increase dose of systemic opioids by 25-50% if already on
- Morphine SR 5-10 mg bid.
- (DB placebo controlled trial)
- Hydrocodone -
- codeine derivative with hydromorphone metabolite
- Codeine -
- CYP 450
- prodrug metabolized to morphine.
- RCT not more effective than placebo
- 10-20 mg po q4h prn
- Dextromethorphan (not recommended Up to Date)
- non opioid, NMDA antagonist
- 10-20 mg q4h prn
- CYP 450 / CYP 2D6
- Nebulized lidocaine for severe cases - no evidence
44
Q
Anti-tussive medications : peripherally acting
A
- Sodium cromoglycate
- 2 puffs bid
- double blind rct significant reduction in cough
- Levodropropizine (inhibits afferent pathways)
- 75 mg po bid
- Benzonatate (anesthetizes stretch receptors of vagal afferent fibres of alveoli, bronchi, pleura)
- 100-200 mg po tid
- Moguisteine ( MOA uncertain)
- 100-200 mg po tid
- as effective as codiene tid
- Gabapentin/pregabalin
- Recommended as second line if opioids not tolerated
- best evidence for GERD cough
- RCT for refractory cough improved cough scores
- low dose 300 mg po od
45
Q
Approach to treating cough
A
- Mild cough :
- non pharm therapies
- honey
- breathing exercises
- cough suppression techniques
- patient counselling
- peripherally acting meds
- benzonatate
- Moderate-severe cough
- opioids first line
- gabapentin/pregabalin second line
- nebulized lidocaine
46
Q
Airway secretions
A
- Mucociliary clearance
- hypersecretion in inflammatory diseases like COPD, infection
- hypertrophy of goblet cells and submucosal cells
- loss of ciliary function
- destruction of surfactant
- alteration of mucus
- purulence : neutrophils, f-actin, apoptotic cells, bacteria
- Cough can clear higher viscosity secretions
- Ciliary clearance works for lower viscosity secretions
47
Q
Mucoactive medications for secretions
A
- increase ability to expectorate sputum or decrease mucus hypersecretion
- Nebulized saline
- Guafenesin (increases hydration of resp tract, reduces viscosity, inhibits cough reflex)
- Carbocysteine (?mOA)
- N-acetylcysteine : mucolytic, antioxidant , antiinflammatory
- 400-1200 mg/day
- nebulized can cause bronchospasm, lack of evidence
48
Q
Bronchorrhoea : definition and pathophysiology
A
- production of > 100 mL of water sputum daily (average 25 ml)
- Causes:
- bronchioalveloar carcinoma
- metastatic cancer
- Chronic bronchitis
- asthma
- bronchiectasis
- hypoxia, dyspnea, exhaustion, chest pain, functional decline, social limitation
- treat disease, radiotherapy, macrolides, anticholinergics, octreotide, steroids, indomethacine, tyrosine kinase inhibitors
49
Q
Noisy airway secretions at end of life
A
- positioning
- gentle oral suction, but not deep suctioning
- discontinue IV fluids
- Glycopyrrolate 0.2-0.4 mg sc q4h prn
- fewer central effects, no BBB
- Scopalamine hyoscine butylbromide (antimuscarinic)
