Management of Breathlessness Flashcards
Tachypnoea is:
Rapid breathing
Hyperpnoea is:
Increased ventilation in response to increased metabolic requirements
Hyperventilation is:
Ventilation in excess of metabolic requirements (HR increased and checked via ECG)
Tachypnoea, hyperpnoea, hyperventilation describe:
increases in ventilation in response to different stimuli. They may represent normal physiological response
Dyspnoea is:
subjective term generally applied to the unpleasant sensation of an awareness of breathing discomfort
Dyspnoea is breathing that is laboured or distressing
Breathlessness is:
one of many descriptions used by patients to convey their experience of dyspnoea: is an awareness of the intensity of breathing or suggests unrewarding respiration/ “chest tightness” or inability to get “air in”
Breathlessness, dyspnoea and shortness of breath are:
often used interchangeably. In chronic patients SOB may be normal so have to check with them if it is changing. Dyspnoea /Breathlessness is the most common symptom in advanced cardiopulmonary disease
Work of breathing (WOB) is:
The Work done to overcome the resistive forces of the airways, lungs and chest wall. Occurs in 2 ways:
- The pressure required to move a volume of gas (Transpulmonary pressure x tidal volume)
- The rate of oxygen consumption by the respiratory muscles, i.e. the oxygen cost of breathing
In health WOB uses 2-5% of total consumption at rest. This can increase to 40% in patients with COPD
During quiet respiration the WOB is performed:
- entirely by the inspiratory muscles
Expiration is passive, powered by the elastic recoil of the lungs - As breathing becomes more difficult the muscles work harder and thus the WOB increases
- The efficiency of the respiratory muscles can be reduced in patients presenting with many different conditions, i.e. COPD (E, CB), IPF
- Many patients cope with reduced respiratory muscle efficiency until something happens e.g. a chest infection and then they deteriorate more rapidly
In health breathing normally occurs:
- Subconsciously and is monitored by multiple sensory systems
- When excessively stimulated this provides sensory feedback which is interpreted as a sense of effort or perceived as dyspnoea
- The perception of increased effort or dyspnoea does not usually elicit distress in health as extra respiratory drive is rewarded by increased mechanical output and ventilation
Those with respiratory or CV disease become aware of:
unpleasant breathing sensations at very low levels of activity, at rest or in response to stress or emotion
Dyspnoea is affected by:
Psychological state Experiences Memory Fear Anxiety Depression Anger/frustration Effort Discomfort
Outcome measures of dyspnoea/SOB:
- Modified Borg scale of perceived breathlessness
- Medical Research Council Quantifies the functional limitations and can provide useful outcome measures, usually done over weeks.
Other causes of ↑WOB and Dyspnoea:
- Increased metabolic rate: Increases ventilation, e.g. fever, exercise
- Cardio-vascular issues: inadequate cardiac output, anaemia
- Deconditioning: Lactate accumulates at low exercise levels causing ↑ ventilation
- Perfusion limitation: Large V/Q mismatch due to wasted ventilation e.g. PE
Anaemia symptoms are:
SOB, fatigue, pallor. Check not bleeding from elsewhere.
Mechanical causes of ↑WOB and Dyspnoea:
- Increased airway resistance
- Increased elastic load
- Decreased energy supply
- Respiratory muscle dysfunction, i.e. reduced power or endurance
- Increased drive to breathe
- Increased alveolar surface tension
Increased airway resistance/resistive load pathologies include:
- Obstructive airways disease - increased secretions
- Asthma - inflammation in the airways
- Chest infection - bronchospasm
- Lung tumour - obstruction in the airway
Increased elastic load pathologies include:
- Fibrotic lungs, Surfactant depletion, Hyperinflation: ↑ alveolar surface tension and reduction in lung compliance increasing the inspiratory muscle work required to overcome the elastic recoil of the lungs.
- Kyphoscoliosis, Ankylosing spondylitis, Pregnancy, Distended abdomen, Obesity, Abdominal surgery: Reduction in chest wall compliance or compliance of abdominal compartment increases insp. Muscle work
Decreased energy supply pathologies includes:
- Eating difficulties: malnutrition (cechexia?)
- Hypovolemic shock: lack of perfusion to the respiratory muscles
Increased drive to breathe pathologies include:
Parenchymal disorders (pneumonia or fibrosis), Acidosis, Anaemia: stimulates nerve impulses from interstitial receptors increasing drive to breathe
Increased alveolar surface tension pathologies include:
Pulmonary oedema, Acute respiratory distress syndrome (ARDS), Surfactant depletion: increased resistance to expansion/reduced compliance increasing insp. muscle work to overcome elastic recoil of lungs
Rib #/flail segment causes high WOB because:
Disrupted mechanics of thoracic cage
A segment of the chest wall which is flail is unable to contribute to lung expansion
What causes high WOB in emphysema:
- Increase in expiratory airflow resistance increases expiratory muscle work
- Severe hypoxaemia may contribute to WOB by stimulating drive to breathe
- Muscles and joints are at a mechanical disadvantage due to passive (trapped air) and dynamic hyperinflation
- Increased inspiratory muscle work occurs to hold open floppy airways (dynamic HI), even during exhalation
Signs of hyperinflation and WOB in emphysema:
Observation - hoovers sign (up on inspiration due to flat diaphragm), intercostal recession, tracheal tug, use of accessory muscles (pec minor/major, serratus ant, scalene, SCM) and pursed lip breathing
CXR - flattened diaphragm/loss of costophrenic angles, horizontal ribs
Clinical manifestations of high WOB include:
- Use of accessory muscles/Shoulder fixation i.e. using upper limb support to enable accessory muscles to assist with inspiration
- Disturbed speech inability to complete sentences suggests significant SOB
- Pursed lip Breathing/Prolonged expiratory time
- Laboured/forced exhalation
- In-drawing/recession/retraction of soft tissues of chest wall on inspiration caused by excessive negative pressure in the chest. This destabilises the chest wall increasing the WOB further
- Altered breathing pattern, i.e. paradoxical breathing, abdominal paradox, hoovers sign
- Abnormalities of rate and depth of breathing (shallow breathing)
- Abnormalities of symmetry of chest wall movement
- Adopting an upper chest breathing pattern
High WOB in the acutely unwell signs include:
- ↑ RR, ↑ HR, ↓ Sp02
- Mouth breathing
- Altered depth and pattern of breathing
- Use of Accessory muscles
- Deranged ABGs
- CO2 retention may cause peripheral vasodilation seen as: warm hands, bounding pulse (palpitations), flapping tremor of the hands. Later signs: Restless, irritable, confused, & coma, ↑ or ↓ HR, ↑ or ↓ BP, Cardiac arrest, fatigue
How to treat breathless patients
- Treat by addressing the cause where possible
- Medication if appropriate
- Physiotherapy
- Pulmonary rehabilitation
- Breathlessness clinic if severe/end stage disease
Physiotherapy management for breathlessness/high WOB include:
- Positioning
- Breathing re-education
- Relaxation
- Balance between supply and demand of energy
- Fan therapy
- Pursed lip breathing
- Sleep
- Pacing, work sequencing
- Non-invasive ventilation (NIV)
When handling acutely breathless patient remember:
Handling requires maximum support/minimum speed and rest between each movement. Patients need to feel some sense of control
Positioning for ease helps to:
- To optimise respiratory muscle function without excess energy demand
- Optimise diaphragm, decrease active fixation of shoulder girdle which uses muscular contraction = results in relaxed muscles of respiration thus lower energy demand
Breathing re-education helps to:
To reduce work of breathing, Increase confidence by:
- Desensitisation to breathlessness, pulmonary rehabilitation
- Teach breath enhancing positions
- Increase awareness of the pattern that is being used
- Encourage relaxation general or specific
- Facilitation of lower chest breathing through relaxation
- In COPD may already have an optimal pattern of breathing but it may be overshadowed with increased tension
Positioning, relaxation and breathing control all aim to:
Eliminate unnecessary muscular activity and thereby REDUCE WOB
The Balance Between Supply and Demand of energy can be thought of as:
A battery where charging the battery is increasing supply of energy and reducing the drain of the battery is decreasing demand of energy.
Factors to increase supply of energy include:
Sleep, Relaxation, Rest, Education, Nutritional Management, Oxygen therapy, Exercise training, Purse lip breathing
Factors to decreased demand of energy include:
Treatment of cause:
Pacing, Work sequencing, Positioning, Breathing control, Stress reduction, Exercise training
Fan therapy is thought to work by:
Desensitisation to breathlessness. Usually used at home, can include just opening the window
Pursed lip breathing is:
- Breathing out through actively through pursed lips keeping the facial muscles relaxed
- Patients who have not learned this technique for themselves may find it helpful.
- The positive pressure on exhalation prolongs expiratory time and reduces airway collapse in floppy airways of emphysema. Particularly good during activity as reduces dynamic hyperinflation during exercise.
Strategies for encouraging good sleep:
No screen time < 2 hours before bedtime. Keep same bed schedule, create a relaxing routine so maybe combine with relaxation in night routine. If insomniac refer to get sleeping pills
Pacing, work sequencing can include:
- Energy conservation by grouping activities
- Coordination of activity with breathing
- Sequencing
- Pacing (slowing down)
NIV acute effects include:
- Reduce PaCO2
- Increase pH
- Increase alveolar ventilation
- Rest respiratory muscles
- Decrease load on the respiratory muscles
NIV indications include:
- Hypercapnia
- Respiratory acidosis
- Respiratory muscle fatigue
- Ventilatory failure
- Weaning from ventilator
- Palliative care- symptom control
- Home ventilation
Some Contraindications and precautions for NIV include:
Severe facial deformity, facial burns, fixed upper airway obstruction
Precautions: pH <7.15 (pH <7.25 and adverse features), GCS <8, confusion and/or cognitive impairment (warrants enhanced observation)
Other treatments include:
Respiratory muscle training: Offers a resistance to inspiration and/or expiration and aims to strengthen the respiratory muscles. Not much evidence to support but may be beneficial in chronic conditions (COPD-E).
Manual therapy: Stretches to the vertebral and shoulder girdle joints to reduce tension, Thoracic mobility exercises. Stretches applied slowly, little and often with monitoring of patients throughout. Ensure drugs are taken prior and provide written instructions for HEP
