8 Reversible Causes of Cardiac Arrest - 4Hs and 4Ts

1. Headache
2. Restlessness
3. Anxiety and confusion
4. Tachypnea: rapid breathing
5. Tachycardia: rapid heart rate
6. Dyspnea: shortness of breath

When severe, hypoxia can cause additional symptoms, such as:

1. Bradycardia: slow heart rate
2. Cyanosis: bluish skin, lips, and nails

Conditions that can cause hypoxia include the following:

1. Airway obstruction
2. Anaemia: low haemoglobin
3. Asthma
4. Asphyxia: insufficient oxygen supply to the body as a result of abnormal breathing
5. Bronchitis: inflammation of bronchial tubes
6. Heart failure
7. Congenital heart defects
8. Emphysema: lung disease that causes shortness of breath
9. Pneumonia
10. Pneumothorax: collapsed lung
11. Pulmonary embolism: blood clot in the lungs
12. Pulmonary oedema (fluid in the lungs)
13. Pulmonary fibrosis (lung scarring)
14. Sleep apnea (sleep disorder in which breathing stops and starts repeatedly)

1. Physical exam: It includes listening to your lungs and heart and checking your skin, lips, and nails to see if they are bluish
2. Pulse oximetry: The doctor places a sensor on your finger to measure the oxygen level in the blood
3. Pulmonary function test: The doctor asks you to blow out into a mouthpiece connected to a machine that measures the functioning of your lungs
4. Arterial blood gas test: The doctor uses a thin needle to draw blood from your artery
5. Six-minute walk test: Measures the distance you can walk on a hard, flat surface in six minutes. The test helps to determine your heart and lung function
6. Imaging tests: X-rays and CT scans get images of the internal organs, helping determine the cause of hypoxia

1. Inhaled steroids or oral medications to open airways and treat asthma
2. Medications to reduce excessive fluid in the lungs
3. Proper oxygenation through a small plug in your nose or a mask that covers the nose and mouth
4. Mechanical ventilation for sudden onset of hypoxia

1. Dry mouth and skin
2. Dizziness
3. Fatigue
4. Unable to urinate or darker urine than normal
5. Muscle cramps

Severe symptoms of hypovolemic shock include:

1. Difficult breathing or rapid breathing
2. Excessive sweating
3. Confusion
4. Unconsciousness
5. Cyanosis: bluish skin and lips
6. Low body temperature
7. Low blood pressure

Loss of blood or fluid from the body is the major cause of hypovolemia, which may occur due to the following:

1. Illness: A condition that causes persistent vomiting or diarrhoea
2. External bleeding: An external burn, injury, cut, or wound
3. Internal bleeding: An underlying condition that results in blood loss within the body, such as gastrointestinal bleeding or ruptured aortic aneurysm
4. Excessive sweating: While participating in strenuous activities
5. Malnutrition or dehydration: Lack of water and salt intake can reduce blood volume

Treatment

1. Physical examination: The doctor will examine the skin and mucous membrane in your nose, mouth, and tongue to check for dryness
2. Pulse, blood pressure, and body temperature: The doctor will take your vitals while sitting and standing and notice the change in symptoms
3. Blood and urine tests: To measure kidney function
4. Focused Assessment with Sonography for Trauma: Ultrasound to identify internal bleeding
5. Echocardiogram: Ultrasound of the heart

The goal of hypovolemia treatment is to increase the amount of fluid in the body through fluid replacement, which includes:

1. Blood transfusion: Donor blood is used to replace lost fluid in the body
2. Intravenous colloids: Large molecules injected into the blood through a tube
3. Intravenous crystalloids: Low-cost salt solutions with small molecules injected into the blood through a tube

1. Pain in the abdomen and diarrhoea
2. Heart palpitations or arrhythmia
3. Chest pain
4. Nausea and vomiting
5. Muscle weakness

1. Kidney disease
2. Metabolic acidosis
3. Diabetes
4. Endocrine disorders
5. High-potassium diet
6. Medications that contain potassium

1. Heart palpitations
2. Fatigue
3. Constipation
4. Numbness and tingling
5. Severe muscle weakness
6. Muscle twitches
7. Muscle cramps
8. Lightheadedness
9. Low blood pressure
10. Arrhythmia
11. Excessive thirst
12. Excessive urination

1. Chronic kidney disease
2. Metabolic alkalosis
3. Diarrhoea
4. Vomiting
5. Low magnesium levels
6. Excessive sweating
7. Eating disorders like bulimia nervosa
8. Alcohol use disorder
9. Diuretics (water pills)
10. Adrenal disorders like Cushing’s syndrome

1. Serum potassium test: To measure potassium levels in the blood
2. Electrocardiogram: Shows changes in heart rhythm as a result of hyperkalaemia

1. Diuretics: Water pills that make you pee more often
2. IV therapy: IV infusions of calcium to protect the heart and IV infusion of insulin to move potassium into the blood cells
3. Dialysis: Helps the kidney remove excess potassium from your blood

1. Blood test: To check potassium levels in the blood
2. Comprehensive metabolic panel: A group of blood tests to check your body’s kidney function and electrolyte balance
3. Electrocardiogram: To measure abnormal heart rhythm

1. Oral potassium supplements: For mild hypokalaemia
2. Intravenous potassium: For more severe cases

1. Shivering
2. Slowed breathing
3. Slurred speech
4. Lack of coordination or clumsiness
5. Weak pulse
6. Confusion or memory loss
7. Drowsiness
8. Loss of consciousness

Cold weather conditions or prolonged exposure to an environment colder than your body are the primary causes of hypothermia. Conditions that lead to hypothermia include:

1. Staying out in the cold for a prolonged period
2. Wearing clothes that aren’t warm enough for the cold weather
3. Falling into water or drowning
4. Not being able to get out of wet clothes or moving to a warm location

The diagnosis of the condition is generally apparent based on the person’s physical signs. The doctor may order blood tests to confirm hypothermia and its severity. 

The treatment aims to increase body temperature to a normal range. The treatment options include:

1. Remove wet clothing
2. Move the person out of the cold
3. Cover the person with blankets
4. Offer warm, nonalcoholic, and non-caffeinated beverages if the person can swallow
5. Use warm compresses
6. Medical treatment: Such as warm intravenous fluids, blood rewarming, and airway rewarming

Symptoms and Signs

1. Acute chest pain
2. Severe shortness of breath
3. Shallow breathing
4. Cyanosis
5. Tracheal deviation from the affected side
6. Absent unilateral breath sounds
7. Subcutaneous emphysema: when air gets into tissues under the skin

1. Traumatic tension, such as an open chest wound (gunshot or stab wound) or closed trauma (rib fracture)
2. Mechanical ventilation: creates an imbalance of air pressure within the chest

Treatment

1. Chest X-ray: Helps determine radiological signs, such as increased transparency of the affected side, increased rib separation, or collapse of the affected lung
2. Ultrasound imaging: To identify pneumothorax and confirm the diagnosis

1. Needle decompression or needle thoracostomy: The doctor inserts a needle into the pleural cavity to decompress tension pneumothorax
2. Chest tube insertion: A flexible chest tube attached to a one-way valve device is inserted into the air-filled space to remove air from the chest cavity. 

Coronary Thrombosis

1. Chest pain
2. Pain in the jaw, head, and ear
3. Pain radiating down the left arm
4. Tightness around the throat
5. Shortness of breath
6. Severe dizziness
7. Fainting

It is caused by the breakage or rupture of plaque in the arteries. Plaque in the arteries is formed by cholesterol in the blood. 

Pulmonary Embolism

1. Shortness of breath
2. Anxiety
3. Chest pain
4. Irregular or rapid heartbeat
5. Rapid breathing
6. Lightheadedness
7. Fainting
8. Bluish skin
9. Weak pulse
10. Spitting up blood

It is most often caused by deep vein thrombosis. Several causes for blood clots in deep veins include:

1. Injury or damage to blood vessels
2. Inactivity for a long time
3. Health conditions that cause blood to clot easily

Coronary thrombosis 

1. Electrocardiogram: reads irregularities in the electrical signals of the heart that might indicate a blood clot or heart attack
2. Cardiac catheterisation: allows doctors to visualise the heart’s arteries and identify a clot

1. Balloon angioplasty: To open the artery
2. Stent placement: To widen the blood vessel and increase the blood flow
3. Blood clot extraction: Useful when the blood clot is large

Pulmonary embolism

1. Chest X-ray: Allows the doctor to see your heart and lungs
2. Electrocardiography: Measures the heart’s electrical activity
3. CT pulmonary angiography: First-choice diagnostic imaging method to look for blood clots in the lungs
4. Ventilation-perfusion scan: Radioactive material is breathed and injected to look for airflow and blood flow in the lungs
5. Pulmonary Angiography: The doctor uses contrast to look at the blood vessels in the lungs

1. Anticoagulants: Blood thinners like warfarin that decrease the blood’s ability to clot
2. Fibrinolytic therapy: Medicines called clot busters are given through an intravenous line to break down the clot
3. Pulmonary embolectomy: Surgery done in severe cases when anticoagulation and fibrinolytic therapy does not work
4. Percutaneous thrombectomy: A catheter is threaded through the blood vessel to break the embolism and pull it out

1. Sharp pain in the chest
2. Dizziness or lightheadedness
3. Fainting
4. Rapid breathing or trouble breathing
5. Fast pulse
6. Heart palpitations
7. Changes in skin colour
8. Jaundice
9. Confusion or agitation

Signs include:

1. Bulging neck veins
2. Muffled heart sounds
3. Low blood pressure

1. Trauma to the chest or heart (inflammation or gunshot)

It can also be caused due to several diseases and conditions, such as:

1. Heart attack
2. Heart cancer
3. Tuberculosis
4. Inflammation or infection of the pericardium
5. Ventricular wall rupture after a heart attack
6. Chronic immune diseases (rheumatoid arthritis, lupus, etc.)
7. Heart or kidney failure
8. Hypothyroidism

1. Echocardiogram: Ultrasound waves to look inside your chest and heart
2. Electrocardiogram: To detect the electrical activity of your heart
3. Chest X-ray: To show fluid buildup around the heart
4. CT scan: To examine the heart and circulatory problems

1. Pericardiocentesis: A needle and catheter are inserted into the pericardium to drain fluid
2. Thoracotomy: An incision is made between the ribs to open the chest and remove fluids

1. Hair loss
2. Fatigue
3. Brain fog
4. Bad breath
5. Brittle toenails
6. Weight gain
7. Nausea
8. Sleep impairment
9. Memory difficulties

1. Illicit drug use: Such as cocaine or opiates
2. Medication overdose: Such as opioids, local anaesthetics, tricyclic antidepressants, benzodiazepines, beta-blockers, and calcium channel blockers

Treatment

1. Core Temperature: Toxin overdose can cause hyper/hypothermia
2. Electrocardiogram: A prolonged QT interval on ECG may indicate toxins
3. Blood and urine test: To check for potential urea and electrolyte disturbance

1. Activated charcoal: Charcoal stops the poison from being absorbed in the blood
2. Antidotes: Substances that prevent or reverse the effect of poison
3. Supportive measures: Like ventilator until the return of spontaneous circulation is achieved