Circulatory distress refers to an impairment of circulatory function which, in the short term, can affect the body’s other vital functions (respiratory function, neurological function) and lead to the victim’s death. Whilst cardiac arrest is a major form of circulatory distress requiring immediate first aid, there are a number of situations in which a victim may show visible signs of circulatory distress without actually being in cardiac arrest. The three vital functions are closely interlinked, and any impairment of circulatory function leads, sooner or later, to a disruption of the others.
Causes
There are several causes of circulatory distress. For example:
- damage to the heart, which becomes unable to pump blood, as in the case of a heart attack or heart failure;
- a reduction in the volume of circulating blood, for example:
- in the event of a haemorrhage;
- in cases of dehydration (diarrhoea, extensive burns, etc.);
- dilatation of the blood vessels (affecting the vessel wall), for example during a severe allergic reaction or severe poisoning.
Some causes are easily identifiable, such as external or visible bleeding. Other causes are suggested by circulatory signs or through an assessment of the circumstances or further investigations.
Risks & Consequences
Impaired circulatory function may prevent oxygen from being delivered to the organs and could rapidly affect the other two vital functions.
Signs
Signs of circulatory distress are identified during the emergency assessment.
Any casualty who has lost consciousness and is not breathing, or whose breathing is abnormal, must be treated as if they are in cardiac arrest.
The key signs of a serious condition indicating circulatory distress and poor blood distribution are:
- the inability to feel the radial pulse whilst the carotid pulse is present
- a drop in systolic blood pressure (< 90 mm Hg or a reduction of > 30% in the usual blood pressure of a patient with hypertension)
Other signs may be present in the event of circulatory distress:
- a heart rate of more than 120 beats per minute (in a person at rest) or less than 40 beats per minute;
- a skin recolouration time (TRC) of more than 3 seconds;
- skin discolouration or paleness, mainly affecting the extremities, the inner surface of the lower eyelid and the lips;
- skin mottling, characterised by alternating pale and purplish patches giving the skin a marbled appearance, predominantly on the front of the knees;
- sweating and a chill in the skin (cold sweats);
- a feeling of thirst;
- agitation, a fear of death;
- the inability to remain seated or standing, characterised by the onset of dizziness, followed by drowsiness, before losing consciousness.
Principle of emergency response
The rescue operation must ensure that:- to immediately stop any obvious cause of circulatory distress, such as external bleeding;
- to improve oxygenation and blood circulation throughout the body and its vital organs by ensuring the patient is positioned correctly and by administering oxygen;
- to receive medical assistance quickly;
- to monitor the victim closely and adapt first-aid measures as the situation develops.