Is the diagnosis of coma difficult to diagnose? 5 key points to clarify the idea!

*For medical professionals only

2 types of causes, 8 concomitant symptoms

Coma refers to the pathological process in which the advanced neural central structure and functional activities (consciousness, sensation and movement) caused by various etiologies are in a serious and widely inhibited state, which is a serious impaired consciousness, which is a common acute and critical illness in the clinic, and its early and accurate diagnosis is the key to the success of
rescue.
This article mainly introduces the concept of coma and its diagnostic ideas
.

1

Coma and Consciousness Disorder Conceptual

Consciousness Disorder is the decrease or disappearance of the central nervous system's ability to respond meaningfully to internal and external stimuli, which is divided into consciousness level disorder and consciousness content disorder
.

Disorders of the level of consciousness are decreased clarity of consciousness, abnormal wakefulness or alertness; Conscious content disorders are higher neural activities (comprehension, orientation, attention, thinking and emotion,
etc.
).
Coma and impaired consciousness are not exactly the same, and both are manifestations
of damage to the central nervous system.

Coma refers to the pathological process in which the higher neural central structure and functional activities (consciousness, sensation and movement) are in a severe and widely suppressed state caused by various etiologies, and is a serious impairment of consciousness, manifested as the continuous interruption or complete loss of some or all of consciousness, which is one of the main manifestations of
brain failure.

2

According to the difference in consciousness, the consciousness disorder can be divided into two categories^[1]

1, arousal disorder (that is, the level of consciousness disorder): according to the degree of drowsiness, lethargy and coma can be divided into three states, coma can be divided into shallow coma, medium coma and deep coma
.

(1) Drowsiness is the mildest disorder of consciousness, mainly manifested as pathological continuous sleep state, which can be awakened by mild stimuli and can correctly answer questions or make various responses, but fall asleep
soon after the stimulation stops.

(2) Drowsiness is a state of consciousness that is deeper than drowsiness and slightly shallower than stupor, the patient cannot automatically wake up, only for strong or repeated stimulation may have a brief awakening, no response to language or incorrect response, once the stimulation is stopped and soon fall into a coma
.

(3) Coma is a serious disorder of consciousness, the patient can not recognize himself and the surrounding environment, the response to external stimuli is very poor or no response, no eye opening movement, spontaneous language movement, rare spontaneous limb movement, physiological reflexes can be normal, weakened or disappeared, vital signs can be stable or unstable
.

a.
Shallow coma is manifested as loss of consciousness, complete inability to respond to the loud response and the second signal system, and simple response to strong painful stimuli, such as compression of the upper orbital margin can appear expression pain and evasion reaction
.
Corneal reflex, cough reflex, swallowing reflex and pancreatic reflex are present, and vital signs are stable
.

b.
Shallow coma is heavy, no response to pain stimuli, the limbs are completely paralyzed, corneal reflex, pupil light reflex, cough reflex and swallowing reflex may exist but are significantly weakened, tendon reflex is hyperreflex, pathological reflex is positive, and respiratory and circulatory functions are generally acceptable
.

C.
Deep coma is the heaviest, the eye is fixed, the pupil is dilated, the corneal reflex, the pupil reflex to light, the cough reflex and the swallowing reflex disappear, quadriplegia, the tendon reflex disappears, the pathological reflex disappears, the vital signs are unstable, and it is in a state of
near death.
Recently, some scholars have included brain death in the category of coma, called excessive coma, which is an irreversible brain injury that is manifested by loss of total brain function, cerebral circulation termination, and the inability of the nervous system to maintain the stability
of the body's environment.

2.
Consciousness content disorder: Consciousness content disorder includes confusion, delirium state and persistent plant state
.

(1) Confusion is mainly manifested as severe confusion of thinking, which can be accompanied by disorientation, hallucinations, delusions, anxiety, etc
.

(2) Delirium state, also known as acute insanity, is manifested by poor level of arousal, disorientation, lack of attention, and serious disorders
of perception, intelligence and emotion.

(3) The persistent plant state is a serious disorder of consciousness, with complete loss of perception, thinking, emotion, memory, will and language activities, no response to external stimuli, and no voluntary movement
of the limbs.

3

Causes

of coma (1) Intracranial diseases:
(2) extracranial diseases (systemic diseases):

4

Accompanying symptoms

of coma (1) body temperature: high fever is more common in severe infections, such as pneumonia, sepsis, meningitis, etc.
, brain lesions invade the hypothalamic thermoregulatory center can appear high fever, more common in cerebral hemorrhage, summer patients with high fever to 41 ° C or above, in high temperature environment should consider heat stroke
.
Hypothermia may occur in a variety of metabolic or toxic comas, or in severely infected people
.

(2) Pulse: a significant slowdown or disappearance of the pulse suggests Aeris syndrome
.
Increased pulse is seen in infections, poisoning with drugs such as belladonna and phenothiazines
.

(3) Respiration: obvious slowdown is seen in the inhibition of the respiratory center caused by morphine, barbiturates and other drug poisoning, deep and thick breathing during cerebral hemorrhage, snoring, exhalation with ammonia odor is seen in uremia, exhalation with rotten apple aroma is seen in diabetic acidosis, exhalation with strong wine odor when alcohol poisoning, exhalation with garlic odor when organophosphorus
poisoning.

(4) Blood pressure: Severe hypertension is common in hypertensive encephalopathy, cerebral hemorrhage, etc
.
Blood pressure is often reduced
in diseases such as anesthetic and hypnotic poisoning, internal bleeding, gram-negative bacillary sepsis, and chronic adrenal insufficiency.

(5) Skin: pale face is seen in shock, uremia coma, flushing is seen in alcohol, belladonna poisoning, heat stroke, etc.
, and the lips are cherry red, and attention should be paid to carbon monoxide poisoning
.

(6) Severe headache, vomiting: subarachnoid hemorrhage
.

(7) Convulsions, sweating: hypoglycemia, hyperthyroidism crisis
.

(8) Hyperventilation: damaged pontine and midbrain cover, respiratory failure, sepsis, metabolic disorders, psychiatric diseases, etc
.

5

Coma Scale 1 Glasgow Score (GCS) Coma Scale
[2] GCS consists of three parts: eye opening reaction, motor response and language response, with a total score of up to 15 points and a minimum of 3 points
.

Clinical GCS scale is commonly used to classify cranial patients, of which 13 to 15 points are mild, 9 to 12 are medium, 3 to 8 are severe, and GCS < 4 indicates poor prognosis<b13>.

GCS scales have the outstanding advantages
of simple and easy to remember due to their small quantitative indicators.

6

Nodal

coma is a common manifestation in neurology, and as a clinician, patients should be identified and judged early and take effective treatment measures to save patients' lives
.

References:[1] Karpenko A,Keegan J.
Diagnosis of Coma[J].
Emerg Med Clin North Am,2021,39(1):155-172.
[2]Chinese Expert Consensus on the Neuromodulatory Surgical Treatment of Chronic Disorders of Consciousness (2018 Edition)[J].
Chinese Journal of Neurosurgery, 2019(05):433-437.