From the Guidelines
Hypoxia is the medical term for low oxygen, which occurs when oxygen supplies are insufficient to meet oxygen demands in a particular compartment, such as alveolar or tissue hypoxia. This condition can be subdivided into four main causes: hypoxaemic, anaemic, stagnant, or histotoxic 1. According to the BTS guideline for oxygen use in adults in healthcare and emergency settings, hypoxaemic hypoxia is present when the oxygen content in the blood is low due to reduced partial pressure of oxygen 1.
Causes and Symptoms
Hypoxia can lead to inadequate oxygen supply to tissues and organs, and common causes include lung diseases, heart conditions, high altitude, and sleep apnea. Symptoms may include shortness of breath, rapid breathing, confusion, and bluish discoloration of the skin (cyanosis).
Diagnosis and Treatment
Hypoxemia, which refers to an abnormally low PO2 in the blood, can lead to hypoxia, and its diagnosis is crucial for prompt treatment 1. The BTS guideline recommends a target SaO2 (and SpO2) ≥94% for most hypoxaemic patients to ensure that the actual oxygen level remains above 90% for most of the time with a 4% margin of safety 1. Treatment depends on the underlying cause but often includes supplemental oxygen therapy, which may be prescribed at various flow rates depending on severity.
Importance of Prompt Medical Attention
Prompt medical attention is essential as prolonged oxygen deprivation can cause organ damage or failure. Mental functioning becomes impaired if the PaO2 falls rapidly to <6 kPa (45 mm Hg, SaO2 <80%), and consciousness is lost at <4 kPa (30 mm Hg, SaO2 <56%) in normal participants 1. Therefore, it is crucial to maintain oxygen saturation above 90% in acute cases and to consider the underlying disease severity and patient age when managing hypoxaemia.
From the Research
Definition of Hypoxia
- Hypoxia is defined as a condition where there is a lower than normal oxygen content and pressure in the cell 2
- It can be caused by hypoxemia (low blood oxygen content and pressure), impaired oxygen delivery, and impaired cellular oxygen uptake/utilization 2
- Hypoxemia is a decreased oxygen partial pressure in arterial blood, which can lead to tissue hypoxia 3
Medical Term for Low Oxygen
- The medical term for low oxygen in the blood is hypoxemia 3, 4, 5
- Hypoxia refers to the condition of low oxygen at the cellular or tissue level 2, 6
Key Points
- Hypoxia can lead to organ failure and life-threatening conditions if not addressed promptly 4
- It is essential to assess the underlying causes of hypoxemia and implement appropriate treatment 3, 5
- Oxygen therapy can be used to manage hypoxemia, and hyperbaric oxygen therapy may be used in certain cases 4, 6