Fainting, Collapse, Coma, Acute Vascular Insufficiency

Fainting, Collapse, Coma, Acute Vascular Insufficiency: Definitions and Terminology

The ability to provide emergency assistance is an unequivocal requirement for any medical professional, regardless of their specialty. Among the most common instances of impaired consciousness that demand urgent medical attention are fainting and coma. Collapse can precede a fainting episode and also deserves close attention.

Definitions of Coma, Collapse, and Fainting

  1. Fainting is characterized by generalized muscle weakness, a decrease in postural tone, an inability to stand upright, and loss of consciousness (Raymond D., Adame et al., 1993).
  2. Coma (from the Greek ‘koma’ meaning deep sleep) is a complete shutdown of consciousness, involving total loss of perception of the surrounding environment and oneself, accompanied by more or less pronounced neurological and autonomic disturbances. The severity of coma depends on the duration of these disturbances. Comas of any etiology (such as ketoacidotic, uremic, hepatic, etc.) share common symptoms: loss of consciousness, reduction or disappearance of sensitivity, reflexes, skeletal muscle tone, and disruptions in autonomic functions (VFO). Additionally, symptoms specific to the underlying disease (e.g., focal neurological symptoms, jaundice, azotemia) are observed.
  3. Collapse (from the Latin ‘collabor’, ‘collapsus’ meaning weakened, fallen) is an acutely developing vascular insufficiency characterized by a fall in vascular tone and a relative decrease in circulating blood volume (CBV). Loss of consciousness in collapse occurs only with a critical reduction in brain blood supply, but this is not a necessary symptom. The key distinction between collapse and shock is the absence of pathophysiological signs characteristic of shock: sympathetic-adrenal reaction, microcirculation disorders, tissue perfusion issues, acid-base imbalance, and generalized cellular function disruption. This condition can arise due to intoxication, infection, hypo- or hyperglycemia, pneumonia, adrenal insufficiency, and physical or mental exhaustion. Clinically, collapse manifests as a sharp deterioration in condition, dizziness, or loss of consciousness (in which case, it is referred to as fainting). The skin becomes pale, cold sweat appears, mild acrocyanosis is noted, breathing is shallow and rapid, and there is sinus tachycardia. The degree of blood pressure reduction reflects the severity of the condition. Emergency assistance is similar to the treatment of fainting.
  4. Acute Vascular Insufficiency is a disorder of venous return due to increased vascular capacity. The presence of acute vascular insufficiency in a patient does not necessarily have to be accompanied by fainting; the latter occurs only when brain blood supply falls below a critical level. Fainting and coma are quantitative syndromes of consciousness impairment. In our country, a working classification of consciousness impairment proposed by A. I. Konovalov et al. (1982) is used, which includes seven levels of consciousness assessment: clear; moderate stupor; deep stupor; sopor; moderate coma; deep coma; and beyond deep coma. Qualitative syndromes of consciousness impairment (delirium, oneiric syndrome, amentia, and twilight states) are covered under “Emergency Conditions in Psychiatry”.