Acute and chronic breathlessness — Rapid | Doctor's Passport Education

Synopsis

Assess breathlessness by tempo and physiology, identify the patient who needs immediate respiratory or cardiovascular support, and investigate overlapping pulmonary, cardiac, haematological, metabolic and functional causes without premature closure.

Start with tempo: seconds to hours suggests obstruction, pulmonary oedema, embolism, pneumothorax, anaphylaxis or metabolic crisis; weeks to months broadens the differential to chronic lung, cardiac, anaemic, neuromuscular and deconditioning causes.
Measure respiratory rate, work of breathing, SpO2, pulse, blood pressure, temperature and mental state before assuming that a normal-sounding history means physiological stability.
Treat hypoxaemia to a prescribed target: usually 94-98%, or 88-92% pending blood gases when hypercapnic respiratory failure is a recognised risk; critical hypoxaemia still requires immediate oxygen.

Key red flags

Acute respiratory or airway threat

Stridor, inability to complete sentences, marked recession, silent chest, exhaustion, cyanosis, falling respiratory effort or reduced consciousness indicates threatened ventilation or airway patency. Treat immediately rather than sending an unstable patient for routine imaging.

Investigation priorities

ABCDE observations, pulse oximetry and exertional toleranceFirst step

Establish immediate severity and whether support or monitored care is required.

Management branches

ImmediateUnstable acute breathlessness

Airway threat, severe work of breathing, shock, altered consciousness, cyanosis or rapidly worsening oxygen requirement.

Call senior and critical-care help, use ABCDE, attach monitoring, gain access and obtain a bedside glucose; position and support the airway and ventilation before pursuing a detailed differential.
Give oxygen to the appropriate target and obtain an early blood gas when hypercapnia or severe gas-exchange failure is possible; do not withhold oxygen from critical hypoxaemia because COPD is suspected.

Initial diagnosisStable but unexplained acute breathlessness

New breathlessness without immediate ABCDE compromise and without a secure diagnosis.

Key medicines

Controlled oxygenTitrate the delivery device to a prescribed saturation target of 94-98% for most acutely ill adults or 88-92% pending gases when hypercapnic respiratory failure risk is present.

Cause-specific emergency treatmentUse the current national and locally adopted protocol for the established emergency, such as severe asthma, anaphylaxis, pulmonary oedema, sepsis or venous thromboembolism.

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