respiratory support

Respiratory Support

Respiratory support encompasses a range of therapies used to improve oxygenation, ventilation, and overall respiratory function in patients with acute or chronic respiratory compromise. It is a fundamental component of emergency medicine, respiratory medicine, anaesthesia, critical care, and perioperative care, helping clinicians maintain adequate gas exchange while treating the underlying cause of respiratory failure.

The level of respiratory support required depends on the severity of the patient’s condition. Some patients require only supplemental oxygen, while others may need non-invasive or invasive mechanical ventilation. The choice of therapy is guided by clinical assessment, oxygen saturation, arterial blood gas analysis, work of breathing, underlying diagnosis, and response to treatment.

Supplemental Oxygen

Supplemental oxygen is the most common form of respiratory support. It increases the fraction of inspired oxygen (FiO₂) delivered to the patient and is used to treat hypoxaemia caused by a wide range of medical conditions.

Oxygen may be delivered using several devices, including:

  • Nasal cannulae
  • Simple face masks
  • Venturi masks
  • Non-rebreather masks
  • High-flow nasal oxygen (HFNO)

The choice of device depends on the patient’s oxygen requirements and clinical condition. Oxygen therapy should always be titrated to appropriate target oxygen saturation ranges and monitored closely to avoid both hypoxaemia and unnecessary hyperoxia.

Non-Invasive Ventilation

Non-invasive ventilation (NIV) provides ventilatory support without the need for endotracheal intubation. Positive pressure is delivered through a tightly fitting face or nasal mask.

Common forms include:

  • Continuous Positive Airway Pressure (CPAP)
  • Bi-level Positive Airway Pressure (BiPAP)

NIV is widely used in acute exacerbations of chronic obstructive pulmonary disease (COPD), cardiogenic pulmonary oedema, selected cases of respiratory failure, and certain postoperative patients. Appropriate patient selection and careful monitoring are essential to maximise its effectiveness.

Mechanical Ventilation

Patients who are unable to maintain adequate oxygenation or ventilation despite less invasive therapies may require invasive mechanical ventilation. This involves placement of an endotracheal tube or tracheostomy connected to a ventilator that supports or completely controls breathing.

Mechanical ventilation is commonly required in patients with:

  • Acute Respiratory Distress Syndrome (ARDS)
  • Severe pneumonia
  • Sepsis
  • Major trauma
  • Neurological impairment
  • Respiratory muscle failure
  • Following major surgery

Ventilator settings are individualised according to the patient’s condition and are adjusted using clinical examination, arterial blood gases, respiratory mechanics, and evidence-based ventilation strategies.

Clinical Assessment

Effective respiratory support requires continuous assessment of the patient’s condition. Healthcare professionals routinely monitor:

  • Oxygen saturation (SpO₂)
  • Respiratory rate
  • Arterial blood gases (ABG)
  • PaO₂/FiO₂ ratio
  • Work of breathing
  • Heart rate and blood pressure
  • Level of consciousness

These measurements help determine whether respiratory support should be escalated, maintained, or gradually reduced as the patient’s condition improves.

Respiratory Support and Clinical Calculators

Several clinical calculators assist healthcare professionals when managing patients receiving respiratory support. Tools such as the PaO₂/FiO₂ Ratio, SOFA Score, NEWS2, and other critical care assessments provide objective information that complements clinical examination and supports evidence-based decision-making.

At MediCalc, respiratory support calculators are designed to help healthcare professionals rapidly assess oxygenation and respiratory function using validated clinical methods. These tools should always be interpreted alongside the patient’s clinical presentation, diagnostic investigations, local guidelines, and professional clinical judgement.

Respiratory support is a cornerstone of modern acute and critical care medicine. When applied appropriately and monitored carefully, it improves oxygen delivery, reduces the work of breathing, and supports recovery while the underlying cause of respiratory compromise is investigated and treated.