Seminar 1Dyspnea and Respiratory Failure

• Ahmad Zulhakim B Mokhtar• Muhammad Halmi B Faisal Thena• Wan Nur Aima Nabila Bt Wan Mohd Zuferi• Liyana Bt Roslan• Norhabsah Bt Omar• Noor Alieya Syafikha Bt zakaria• Mahzalena Bt Aziz’s

What is Dyspnea ???

• A subjective sensation of breathlessness Class 1 Disease present but no

dyspnea, or dyspnea only on heavy exertion

Class 2 Dyspnea on moderate exertion

Class 3 Dyspnea on mild exertion

Class 4 Dyspnea at rest

Grade 0 Breathlessness with strenuous exercise

Grade 1 Short of breath when hurrying on level ground or walking up a slight hill

Grade 2 On level ground, walk slower than people of the same age because of breathlessness / have to stop for breath when walking at my own pace on the level

*NYHA *MMRC

What are the types ???

• Orthopnea - > breathlessness on lying flat

• Paroxysmal nocturnal dyspnea (PND) -> when patient is woken from sleep, fighting for breath.

Etiology

Dysp

nea

Respiratory

Cardiac

Anaemia

Non - cardiorespiratory

Psychogenic

Acidosis ( compensatory respiratory alkalosis)

Hypothalamic lesions

Respiratory

Airway disease Parenchymal disease

Pulmonary infection

Chest wall and pleura

Clinical examination ( Talley and O’Connor)

How to differentiate ???Lung disease Heart disease

History of respiratory disease History of hypertension, cardiac ischemia or valvular heart disease

Slow development Rapid development

Present at rest Mainly on exertion

Productive cough is common Cough uncommon and then ‘dry’

Aggravated by respiratory infection

Usually unaffected b respiratory infection

Murtagh’s General Practice

Pathogenesis & Pathophysiology Of Dyspnea

Mechanism Of Dyspnea

Clinical Manifestation Of Dyspnea

It’ll Leave You

Breathless

• Onset (Minutes, Hours, Days, Months, Years)

• Position (Opthopnea, Platypnoea, Trypopnoea)

• Associated Symptoms

Differential DiagnosisModes of Onset, duration and

progressionDDX

Acute Onset and Progressed Rapidly over a few Minutes

Pulmonary Thromboembolism Pneumothorax Left Ventricular Failure Asthma Inhaled Foreign Body

Gradually onset and Progressed Rapidly over Hours to Days

Pneumonia Asthma Exacerbation of COPD

Gradually Onset and Progressed Relentlessly over Weeks to Months

Anaemia Pleural Effusion Respiratory Neuromuscular

DisordesGradually Onset and Progressed Relentlessly over Months to Years

COPD Pulmonary Fibrosis Pulmonary Tuberculosis

Differential DiagnosisCommonly Associated Symptoms

(Acute Onset)DDX

No Chest Pain Pulmonary Embolism Pneumothorax Metabolic Acidosis Hypovolemia/shock Acute left ventricular failure/

pulmonary oedemaPleuritic Chest Pain Pneumonia

Pneumothorax Pulmonary embolism Rib Fracture

Central Chest Pain MI with Left Ventricular Failure Massive Pulmonary

Embolism/Infacrtion Wheeze and Cough Asthma

COPD

What is respiratory failure ???

• Respiratory system ->

• It occurs when pulmonary gas exchange is sufficiently impaired to cause hypoxemia with or without hypercapnia

• In practical terms -> present when ;– PaO2 is < 8 kPa (60 mmHg) or – PaCO2 is > 6.6 kPa (50 mmHg)

Consists of gas – exchanging organ (lungs) and a

ventilatory pump (respiratory muscles / thorax)

Type 1 Respiratory Failure

PaO2 = lowPaCO2 = Normal or low

Type 2 Respiratory Failure

PaO2 = lowPaCO2 = high

AetiologyRib cage Severe kyphosis

Muscle Dermatomyocitis

BrainTrauma to midbrain

PNSGuillain Barre Syndrome

Spinal CordComplete transection between cervical 3 - 5

LungsAsthmaPulmonary EdemaPneumothorax

Neuromuscular Junction Myasthenia Gravis

Clinical assesment

• Use of accessory muscles of respirations

• Intercostal recession • Tachypnoea *• Tachycardia• Sweating • Inability to speak• Asynchronous respiration• Paradoxical respiration

Pathogenesis/Pathophysiology Of Respiratory Failure

19

Clinical Manifestation Of Respiratory Failure

Convulsion, Mental

disorder, Coma

Bounding Pulse , Tachycardia, MI,

Arrythmias

Cyanosis

DYSPNOEA, Abnormal

Breath Rythm

Case Scenario

• A 25-year-old woman presents with shortness of breath. She reported that in high school, she occasionally had shortness of breath and would wheeze after running. She experiences the same symptoms when she visits her friend who has a cat. Her symptoms have progressively worsened over the past year and are now a constant occurrence. She also finds herself wheezing when waking from sleep approximately twice a week.

INVESTIGATIONS

INVESTIGATION EXAMPLE

Blood tests Full Blood Count (FBC)Urea & ElectrolyteC-Reactive ProteinArterial Blood Gas (ABGs)

Radiology chest X-rayMicrobiology Sputum

Blood cultures (if febrile)

Longmore, M., Baldwin, A., B. Wilkinson, I., & Wallin, E. (2014). Respiratory Failure. In Oxford handbook clinical medicine (Ninth ed., p. 180). Oxford.

MONITORING OF RESPIRATORY FAILURE

PULSE OXIMETRY• Lightweight oximeters can be applied to an ear lobe/ finger• Measure the changing amount of light transmitted through the pulsating

arterial blood and provide continuos, non-invasive assessment of arterial oxygen saturation

BLOOD GAS ANALYSIS• Interpretation of the results of blood gas analysis can be considered in

two separate parts:• 1) Disturbances of acid base balance• 2) Alterations in oxygenation

CAPNOGRAPHY• continuous breath by breath analysis of expired dioxide concentration• Used to :• -confirm tracheal intubation• -continuously monitor end-tidal PCO2• -detect apparatus malfunction• -detect acute alterations in cardiorespiratory function

Management of Respiratory Failure

• Treat underlying illness• Oxygen therapy-CPAP, BPAP

MV= RR x TV

TYPE 1 RESPIRATORY FAILURE TYPE 2 RESPIRATORY FAILURE Give oxygen (35-60%) by

facemask to correct hypoxia

Assisted ventilation if PO2<8kPa despite 60% O2

start oxygen therapy at 24% O2

Don’t leave hypoxia untreated-with care

Recheck ABG after 20 minutes.

- If PCO2 is steady or lower, increase O2 concentration to 28%.

- If PCO2 has risen >1.5kPa and patient still hypoxic, consider respiratory stimulant or assisted ventilation (NIPP, rarely respi stimulant (doxapram 1.5-4mg/min))

If this fails, consider intubation and if appropriate.

Guidelines For The Management Of Acute Severe Asthma In Adults

Long term poorly controlled asthma Asthma worsening for some days or weeks.

Features of acute severe asthma :

Too breathless to complete sentences in one breath RR 25 breaths/min PR 110/min PEF £ 50% predicted or best value

IMMEDIATE TREATMENTHigh concentration oxygen (>40%)

High doses of inhaled β2 agonist via nebuliser

Prednisolone tablets 30-60mg.

*IV aminophylline 250mg slowly over 20 minutes

Guidelines For The Management Of Chronic Asthma In Adults

DRUGS TYPES AIM

Bronchodilator drugs

Beta2 agonists

Anticholinergics

Methylxanthines

Relieve bronchospasm.

Improve symptoms.

Anti inflammatory

drugs

Corticosteroids

Sodium cromoglycate (Intal)

Treat airway inflammation.

Treat bronchial hyperresponsiveness.

Prevent recurrent attacks.

(a) Beta-2 Adrenoreceptor Antagonist

Salbutamol Salmeterol

Mechanism Of Action

bronchial SMC

(b) Anticholinergic - Ipratropium Bromide

competitive inhibition of muscarinic receptors (M3-type) on bronchiole smooth muscle

by antagonizing ACh action prevents ↑ in intracellular

calcium concentration

Bronchodilatation

(c) Methylxanthines

Theophylline Aminophylline

* (Phosphodiesterase inhibitors)

Mechanism Of Action

(d) Corticosteroids

Prototype :

Prednisolone (oral) Hydrocortisone (iv) Beclomethasone (inhalation)

Mechanism Of Action

They do not relax airway smooth muscle directly but reduce bronchial reactivity & frequency of asthma exacerbation

•THANK YOU