Carbon monoxide poisoning

Carbon monoxide or CO is extremely toxic and can be very dangerous to people when inhaled. Even a small amount can be dangerous leading to neurological damage or hypoxic injury. Symptoms of carbon monoxide poisoning are vertigo, headache, confusion and lightheadedness. Further exposure to carbon monoxide can lead to death. This is because carbon monoxide hampers the oxygen-carrying capacity of the blood. Other problems of carbon monoxide poisoning are hyperventilation, irregular heart beat, seizure, loss of memory and difficulty in breathing. Treating carbon monoxide poisoning with oxygen allows removal of the toxic gas from the blood.

Hypoxia

The body needs a specific amount of Oxygen to function normally and when this amount is lowered the body experiences hypoxia. Hypoxia literally means lack of oxygen for effective ventilation.

Hypoxemia refers to a state of abnormally low level of Oxygen in the blood.
Anoxia refers to the condition of absence of Oxygen supply to an organ or tissue
Anoxemia refers to the condition where the blood stream contains below normal amount of Oxygen.

Hypoxia is primarily classified into:

Generalized hypoxia: affects the entire body, may occur in normal healthy people when they scale high altitudes.
Local hypoxia: affects one particular region of the body.

When the level of oxygen in the blood reduces, it leads to the condition. People suffering from conditions like ischemia or blockage/constriction of blood vessels may suffer from hypoxia. In general when people travel from low to high altitudes, they may face this problem as the oxygen level depletes with altitude.

Hypoxia causes

Any condition wherein the body is deprived of oxygen can lead to hypoxia. Major causes that lead to the condition include:

• Severe head trauma
  
• Ischemia
  
• Asthma Severe Asthma can result in hypoxia and in Hypercarbia or Hypercapnia (elevated levels of Carbon dioxide CO₂ in blood)
  
• Pulmonary embolism
  
• Carbon monoxide poisoning
  
• Chronic alveolar hypo ventilation
  
• Shock can result in cellular hypoxia in the extremities
  
• Suffocation
  
• Choking
  
• High altitude climbing
  
• Inadequate ventilation

Types of hypoxia

Hypemic hypoxia: Obstruction in the ability of the blood to deliver oxygen, caused by carbon monoxide poisoning.

Anemic Anoxia: Occurs due to a decrease in the hemoglobin or RBC making it too little for the blood to carry oxygen. Anemia may be the result of iron deficiency, hemorrhage or shortened life span of RBC owing to an autoimmune disease.

Histotoxic: When the required amount of oxygen reaches the body part, however it does not utilize it because of its reduced ability, it is called as histotoxic hypoxia. Cyanide poisoning, for example, incapacitates a cellular enzyme essential for oxygen utilization. Other causes include: Alcohol, narcotics, acetone, formaldehyde and some anesthetic agents.

Hypoxic: Also called as Hypoxemic Anoxia: When the body does not receive the required amount of oxygen it leads to low partial pressure of oxygen in the blood thus leading to hypoxic hypoxia. The oxygen pressure of the blood which gets supplied to other body tissues is too low to push and flood the hemoglobin with oxygen. High altitude has lower density of air and lower pressure of oxygen than at sea level. Altitude Sickness occurs because the partial pressure of oxygen decreases with altitude. Hypoxemia is the direct result of lower oxygen in the high altitude which translates to lower level oxygen in the blood.

Stagnant: Obstruction of blood that carries oxygen. It can be due to exposure to cold, diseases which stifle blood circulation to the extremities or ergot poisoning.

Pulse Oximetry, a non invasive test is useful to diagnose Hypoxia. A blood test like serum lactate test can show elevated levels of lactic acid - the result of starvation of oxygen in tissues. The normal level of lactic acid is less than 2 mmol/L. However an increase in lactic acid alone does not indicate hypoxia and some form of Anoxia does not increase the lactic acid concentration. Symptoms may be dangerous on the onset and may include the following:

Generalized hypoxia

• Tachypnea or rapid breathing
  
• Severe headache
  
• Dizziness
  
• Nausea
  
• Tingling sensation
  
• Visual impairment
  
• Shortness of breath
  
• Bluish tint on the lips or on finger tips
  
• Coma
  
• Seizures
  
• Euphoria
  
• Mental fatigue
  
• Muscle fatigue

• Hot and cold flashes
  
• Discoloration of skin
  
• Pain in the area of hypoxia
  
• Severe hypoxia may cause gangrene

Hypoxia Treatment

Some types of Hypoxia cannot be prevented. Treatment depends on the severity of the condition and the appearance of the clinical symptoms. Treatment may include the following:

• Restoration of the tissue oxygen by supplementing the air supply with 100 % oxygen.
  
• Blood pressure and heart rate should be brought back to normal.
  
• In case of high altitudes, the person should be given sufficient rest and should not climb any further.
  
• Hypoxemic hypoxia patients can be put on blood transfusion.
  
• Proper medication and timely treatment can help save the life.

CK blood test

A Creatinine Kinase test is a blood test that measures the levels of Creatinine phosphokinase (CPK). It is an enzyme found predominantly in the heart tissue, brain and skeletal muscle. The CK blood test is commonly used to diagnose the existence of heart muscle damage. The CK blood test result shows an increase above normal in a person's blood test about six hours after the start of a heart attack.

It reaches its peak in about 18 hours and returns to normal in 24 to 36 hours. When the total CPK level is substantially elevated, then it is indicative of injury or stress to heart, brain or skeletal areas. The small amount of CPK that is normally in the blood comes from the muscles. The CPK blood test also helps in cost-effective management of people with suspected coronary atherosclerosis. It also evaluates the extent of muscle damage caused by drugs, trauma or immobility.

Abnormal CK-MB (one of three CK isoenzymes) or troponin levels are associated with Myocyte Necrosis and the diagnosis of Myocardial infarction. The Cardiac Markers of Cardiac Myocyte Necrosis (damage to the Cardiac muscle cells), myoglobin, CK, CK-MB and troponin I and T are primarily used to identify acute Myocardial Infarction.

It is used in early detection of dermatomyositis and polymyositis. It is also used to distinguish malignant hyperthermia from a post operative infection. It helps to discover carriers of muscular dystrophy.

The normal range for Creatinine Kinase (CK or CPK) blood test:
Male: 38 - 174 units/L
Female: 96 - 140 units/L

Increased levels of CK also can be found in viral myositis and hypothyroidism. Higher than normal CPK levels is indicative of the following conditions:

• Heart attack
  
• Myocarditis
  
• Convulsions
  
• Delirium Tremens
  
• Electric shock
  
• Muscular dystrophy
  
• Pulmonary infarction
  

CK MB

Serum CKMB levels are tested to check for myocardial injury. It is another important cardiac marker. The primary source of CKMB is myocardium although it is also found in skeletal muscle. Typically CKMB tests have now been replaced by Troponin test. But in cases of abnormal Troponin assay results or suspected re-infarction in the hospital, the CKMB serum test is still used.

High levels of CK MB are noticed in cases of polymyositis and rhabdomyolysis. Patients suffering pulmonary embolism, hypothyroidism, and muscular dystrophy or carbon monoxide poisoning can also show higher levels of serum CKMB. The reference range is about 56.2 pg/mL.