SYMPTOMS

What is coma?

Coma usually refers to a complete loss of consciousness and is a manifestation of critical illness. After entering a coma, the patient loses consciousness, spontaneous movements disappear, and responses to external stimuli are diminished or absent.

What are the typical manifestations of coma patients?

The typical manifestations of coma include unresponsiveness to calls and diminished or absent reactions to painful stimuli.

Clinically, coma is classified into mild, moderate, and deep coma. The clinical manifestations vary depending on the severity of the coma, as analyzed below:

1. In mild coma, the patient responds to pain and can perform protective movements but cannot communicate verbally. Pupillary light reflex may remain normal (i.e., the pupils constrict when exposed to direct or indirect light stimulation).
2. In moderate coma, the patient does not respond to mild stimuli but may react to severe pain stimuli. However, protective movements and verbal communication are absent, and pupillary light reflex is sluggish.
3. In deep coma, all reflexes disappear, and the patient shows no response to any stimulation. Pupillary reflexes are also absent.

What are the common types of coma?

Clinically common types of coma include coma caused by acute poisoning, head trauma, cardiovascular accidents, hypoglycemia, and endocrine diseases^[1]. Specific examples are analyzed below:

1. Coma caused by acute poisoning: If a patient is exposed to toxic chemicals and suddenly experiences dizziness, nausea, blackouts, or even loss of consciousness, it is considered acute poisoning.
2. Coma caused by head trauma: Head trauma can lead to cerebral edema, damaging the brain regions responsible for wakefulness and perception, resulting in coma.
3. Coma caused by cardiovascular accidents: If a patient with high-risk factors such as hypertension or heart disease suddenly experiences coma accompanied by hemiplegia, acute cerebrovascular accidents (e.g., massive cerebral infarction or cerebral hemorrhage) should be considered. Sudden chest pain with coma may indicate cardiogenic syncope.
4. Coma caused by hypoglycemia: If a patient with poor physical condition has not eaten for an extended period and experiences palpitations, sweaty hands, blurred vision, or other precursors, hypoglycemic coma should be considered.
5. Coma related to diabetes: If a diabetic patient who has not been taking glucose-lowering medication regularly suddenly falls into coma with a fruity breath odor, diabetic ketoacidosis should be suspected. Other possibilities include hyperosmolar hyperglycemic coma and hypoglycemic coma.

Which groups are at high risk for coma symptoms?

High-risk groups for coma symptoms include individuals with chronic conditions such as hypertension, diabetes, heart disease, and chronic obstructive pulmonary disease (COPD). Specific analyses are as follows:

1. If a long-term hypertensive patient suddenly experiences coma with nausea and vomiting, hypertensive encephalopathy or cerebral hemorrhage due to ruptured blood vessels should be considered.
2. If a diabetic patient with poorly controlled blood sugar suddenly falls into coma, diabetic ketoacidosis, hyperosmolar hyperglycemic coma, or hypoglycemic coma due to excessive glucose-lowering medication should be suspected.
3. If a patient with heart disease (e.g., long-term atrial fibrillation) who has not received standardized anticoagulation therapy suddenly experiences coma with hemiplegia, cardiogenic embolism leading to massive cerebral infarction should be considered.
4. If a patient with COPD experiences worsening symptoms followed by coma, pulmonary encephalopathy should be suspected as the cause.

TREATMENT

How to Alleviate Symptoms After a Patient Falls into a Coma?

If you find someone in a coma, call 120 immediately or seek emergency medical attention. Shout for help (especially from those trained in CPR). If there is no pulse or breathing, perform CPR as soon as possible to avoid missing the critical rescue window. Keep the head tilted to one side to prevent aspiration if the patient vomits.

After hospitalization, treatment for coma primarily focuses on addressing the underlying cause, followed by brain-protective and awakening therapies^[1]. Specific approaches include:

1. For a patient in a coma due to ketoacidosis, intravenous insulin infusion should be administered to gradually lower blood sugar, followed by fluid replacement. Acidosis correction and electrolyte balance restoration may also be necessary to alleviate the coma.
2. For coma caused by acute poisoning, immediate gastric lavage, laxatives, or antidotes should be administered.
3. For coma resulting from cerebrovascular diseases (e.g., cerebral hemorrhage), measures include dehydration to reduce intracranial pressure, infection prevention if needed, and brain-protective therapies. Severe cases may require surgical intervention, such as craniotomy, to relieve symptoms.
4. For hypoglycemia-induced coma, intravenous injection of 50% glucose solution should be administered promptly.

DIAGNOSIS

Which departments should comatose patients visit?

If a comatose patient is unresponsive and cannot be awakened, immediate medical attention or calling 120 is necessary. They should go to the emergency department for prompt treatment.

What are the common causes of coma?

Coma may result from damage to the brainstem reticular activating system or widespread cerebral cortex dysfunction, which can be caused by various factors. Head trauma, intracranial hemorrhage, or cerebral hypoxia may lead to brain damage and subsequent coma, which can be temporary or permanent.

• Head trauma: Head injuries can cause cerebral edema, damaging brain areas responsible for wakefulness and awareness, leading to coma.
• Intracranial hemorrhage: Conditions such as hypertension, cerebral aneurysms, or tumors causing brain bleeding may result in coma.
• Cerebral hypoxia: Sudden interruption of blood flow and oxygen to the brain due to cardiac arrest or suffocation can impair brain function, often causing coma.

Other common causes include extremely high or low blood sugar, poisoning, seizures, and brain infections.

What tests are required for comatose patients in the hospital?

Severely impaired brain function patients often cannot undergo extensive testing due to critical conditions, making clinical observation crucial. Some tests are performed in the emergency room to quickly identify the cause, while others assess the severity and prognosis in chronic coma cases.

Additional tests may include neuroelectrophysiological exams (e.g., EEG), serum biochemical tests, imaging (e.g., MRI, CT), and cerebral blood flow studies (e.g., transcranial Doppler).

1. Clinical assessment: Doctors use scales like the Glasgow Coma Scale to evaluate recovery progress.
2. Neuroelectrophysiological tests: EEG and evoked potentials monitor brain function and sensory responses, aiding recovery prediction.
3. Serum biochemical tests: Detect brain injury markers like neuron-specific enolase.
4. Imaging: MRI or CT scans help identify causes and assess treatment outcomes.
5. Cerebral blood flow tests: Such as transcranial Doppler ultrasound.

Additional tests may be needed based on symptoms:

1. Chronic obstructive pulmonary disease (COPD) patients with sudden coma may require arterial blood gas analysis and chest CT.
2. Diabetic patients with sudden coma need urgent blood glucose and ketone tests.
3. Chronic liver disease patients may require blood ammonia tests for hepatic encephalopathy.
4. Patients with fever and headache before coma may need lumbar puncture for suspected infections or bleeding.

What treatments are needed for comatose patients?

Treatment targets the underlying cause. Family members should provide relevant medical history to aid diagnosis and care. Examples include:

1. Sepsis-induced coma: Blood cultures guide antibiotic selection.
2. Hyperosmolar coma: Fluid therapy to correct imbalances.
3. Hypoglycemic coma: Glucose infusion to restore blood sugar.
4. Carbon monoxide poisoning: Hyperbaric oxygen therapy; gastric lavage for drug overdose.
5. Surgery: Relieves intracranial pressure from edema or removes tumors if feasible.
6. Stimulation therapies: Electrical stimulation may aid recovery if coma persists after acute treatment.

POTENTIAL DISEASES

What diseases can cause coma?

Clinically, many diseases can lead to coma, with common ones including cerebrovascular accidents, cardiogenic embolism, intracranial infections, epilepsy, and others. Specific examples are analyzed below:

1. If a patient with a history of hypertension suddenly experiences a headache followed by coma, conditions such as cerebrovascular accidents, like a cerebral hemorrhage, should be considered.
2. If a patient with uncontrolled rapid ventricular rate atrial fibrillation suddenly develops coma accompanied by hemiplegia, cardiogenic cerebral embolism should be suspected.
3. If a patient has a headache and fever followed by coma, intracranial infection should be considered as a possible cause.
4. If a patient suddenly experiences generalized convulsions followed by coma, epilepsy should be considered as the underlying cause.
5. If a diabetic patient becomes comatose after taking hypoglycemic medication, the possibility of hypoglycemic coma should be evaluated.
6. Additionally, drug overdoses, such as excessive sleeping pill intake, may also lead to coma. Family members might find empty medication boxes at home, providing diagnostic clues for doctors.

How to prevent coma?

Preventing coma primarily involves two approaches:

1. Avoid trauma, particularly head injuries.
2. Properly manage underlying diseases that may lead to coma, such as diabetes, liver diseases, or infections. Seek medical attention early if symptoms like lethargy, sluggishness, or mild confusion appear. Diabetic patients using hypoglycemic drugs should have a glucose meter to detect hypoglycemic coma promptly.

What should be considered in home care for comatose patients?

Daily care for comatose patients mainly includes the following precautions:

1. Nutritional care: Doctors typically provide nasogastric tubes, nasojejunal tubes, or gastrostomy for nutritional support. Family members should learn proper feeding methods, such as how to administer food and maintain tubes. Due to weakened or absent gag reflexes, feeding should be slow to prevent reflux and choking. Elevate the head of the bed during feeding and monitor for bloating, coughing, constipation, or malnutrition, consulting community or family doctors as needed.
2. Sphincter control: Doctors may use catheters, external collection bags, or absorbent pads to avoid complications from long-term catheterization (e.g., urinary tract infections, bleeding, or stones). Family members should monitor urination and seek medical help if abnormalities occur.
3. Preventing deformities and controlling muscle tone: Most comatose patients develop limb deformities, spasms, or atrophy. Doctors may prescribe medications, and family members should assist with limb exercises, massage (to prevent deep vein thrombosis), hand gripping exercises to maintain wrist extension, and soft foot support to prevent ankle contractures and foot drop.
4. Repositioning: Regularly help the patient sit or stand to reduce muscle spasms and potentially aid in arousal. Frequent repositioning prevents pressure sores.
5. Infection prevention: Maintain oral hygiene to reduce the risk of lung infections. Clean the patient’s mouth daily with moistened cotton balls or oral care solutions. Since prolonged bed rest increases the risk of lung infections, reposition and pat the back every 1–2 hours. Antibiotics may be necessary if pneumonia develops.
6. Preventing thrombosis: Immobility increases the risk of blood clots, which may lead to life-threatening pulmonary embolism. Preventive measures include foot compression pumps or anticoagulant therapy if needed.