Saturday, 2 November 2013

Lung Cancer Part-4



Lung Cancer Part-4


What are lung cancer symptoms and signs?

Symptoms of lung cancer are varied depending upon where and how widespread the tumor is. Warning signs of lung cancer are not always present or easy to identify. Lung cancer may not cause pain or even any symptoms at all in some cases. A person with lung cancer may have the following kinds of symptoms:
  • No symptoms: In up to 25% of people who get lung cancer, the cancer is first discovered on a routine chest X-ray or CT scan as a solitary small mass sometimes called a coin lesion, since on a two-dimensional X-ray or CT scan, the round tumor looks like a coin. These patients with small, single masses often report no symptoms at the time the cancer is discovered.
  • Symptoms related to the cancer: The growth of the cancer and invasion of lung tissues and surrounding tissue may interfere with breathing, leading to symptoms such as cough, shortness of breath, wheezing, chest pain, and coughing up blood (hemoptysis). If the cancer has invaded nerves, for example, it may cause shoulder pain that travels down the outside of the arm (called Pancoast syndrome) or paralysis of the vocal cords leading to hoarseness. Invasion of the esophagus may lead to difficulty swallowing (dysphagia). If a large airway is obstructed, collapse of a portion of the lung may occur and cause infections (abscesses, pneumonia) in the obstructed area.
  • Symptoms related to metastasis: Lung cancer that has spread to the bones may produce excruciating pain at the sites of bone involvement. Cancer that has spread to the brain may cause a number of neurologic symptoms that may include blurred vision, headaches, seizures, or symptoms of stroke such as weakness or loss of sensation in parts of the body.
  • Paraneoplastic symptoms: Lung cancers frequently are accompanied by symptoms that result from production of hormone-like substances by the tumor cells. These paraneoplastic syndromes occur most commonly with SCLC but may be seen with any tumor type. A common paraneoplastic syndrome associated with SCLC is the production of a hormone called adrenocorticotrophic hormone (ACTH) by the cancer cells, leading to oversecretion of the hormone cortisol by the adrenal glands (Cushing's syndrome). The most frequent paraneoplastic syndrome seen with NSCLC is the production of a substance similar to parathyroid hormone, resulting in elevated levels of calcium in the bloodstream.
  • Nonspecific symptoms: Nonspecific symptoms seen with many cancers, including lung cancers, include weight loss, weakness, and fatigue. Psychological symptoms such as depression and mood changes are also common.

When should one consult a doctor?

One should consult a health care professional if he or she develops the symptoms associated with lung cancer, in particular, if they have

  • a new persistent cough or worsening of an existing chronic cough
  • blood in the sputum
  • persistent bronchitis or repeated respiratory infections
  • chest pain
  • unexplained weight loss and/or fatigue
  • breathing difficulties such as shortness of breath or wheezing

Lung Cancer Part-1

Lung Cancer Part-1

Lung Cancer Symptoms and Signs

Lung cancer is the most common cancer in men and the fifth most common in women, even causing more cancer-related deaths in women than breast cancer. The incidence of lung cancer is strongly correlated with cigarette smoking, with about 90% of lung cancers arising as a result of tobacco use.
  • Lung cancer is the number one cause of cancer deaths in both men and women in the U.S. and worldwide.
  • Cigarette smoking is the principal risk factor for development of lung cancer.
  • Passive exposure to tobacco smoke also can cause lung cancer.
  • The two types of lung cancer, which grow and spread differently, are the small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC).
  • The stage of lung cancer refers to the extent to which the cancer has spread in the body.
  • Treatment of lung cancer can involve a combination of surgery, chemotherapy, and radiation therapy as well as newer experimental methods.
  • The general prognosis of lung cancer is poor, with overall survival rates of about 16% at 5 years.
  • Smoking cessation is the most important measure that can prevent the development of lung cancer.

What is lung cancer?

Cancer of the lung, like all cancers, results from an abnormality in the body's basic unit of life, the cell. Normally, the body maintains a system of checks and balances on cell growth so that cells divide to produce new cells only when new cells are needed. Disruption of this system of checks and balances on cell growth results in an uncontrolled division and proliferation of cells that eventually forms a mass known as a tumor.
Tumors can be benign or malignant; when we speak of "cancer," we are referring to those tumors that are malignant. Benign tumors usually can be removed and do not spread to other parts of the body. Malignant tumors, on the other hand, grow aggressively and invade other tissues of the body, allowing entry of tumor cells into the bloodstream or lymphatic system and then to other sites in the body. This process of spread is termed metastasis; the areas of tumor growth at these distant sites are called metastases. Since lung cancer tends to spread or metastasize very early after it forms, it is a very life-threatening cancer and one of the most difficult cancers to treat. While lung cancer can spread to any organ in the body, certain locations -- particularly the adrenal glands, liver, brain, and bones -- are the most common sites for lung cancer metastasis.
The lung also is a very common site for metastasis from tumors in other parts of the body. Tumor metastases are made up of the same type of cells as the original (primary) tumor. For example, if prostate cancer spreads via the bloodstream to the lungs, it is metastatic prostate cancer in the lung and is not lung cancer.

The principal function of the lungs is to exchange gases between the air we breathe and the blood. Through the lung, carbon dioxide is removed from the bloodstream and oxygen from inspired air enters the bloodstream. The right lung has three lobes, while the left lung is divided into two lobes and a small structure called the lingula that is the equivalent of the middle lobe on the right. The major airways entering the lungs are the bronchi, which arise from the trachea. The bronchi branch into progressively smaller airways called bronchioles that end in tiny sacs known as alveoli where gas exchange occurs. The lungs and chest wall are covered with a thin layer of tissue called the pleura.

Friday, 1 November 2013

Arsenic Poisoning Part-5



Arsenic Poisoning Part-5


How is arsenic poisoning treated?

Acute toxic inorganic arsenic exposure and arsine gas exposure can rapidly result in death, and there are only a few ways to possibly save the patient's life. Hemodialysis can remove arsenic from the bloodstream, but only before it binds to the tissues so there is only a short time window for this treatment to work. Similarly, arsine binds to and causes rapid destruction of red blood cells, so blood transfusions and exchange transfusions may help the patient. In addition, if the arsenic was ingested, stomach or bowel irrigation may be attempted, but there is no good data to indicate these will be successful. Consultation with a nephrologist and a toxicologist as soon as possible is recommended; other consultants may need to be called (hematologist, psychiatrist, or others).
Chelation therapy (the use of drugs that selectively bind and effectively inactivate substances) is usually begun quickly through an intravenous line. The drug and the bound arsenic is then excreted through the urine. The chelation drug of choice is Dimercaprol (also termed BAL in oil); Succimer (DMSA) has also been used successfully, and Dimerval (DMPS) may also work as a chelator, but it is not readily available in the US.

What is the prognosis (outcome) of arsenic poisoning?


If the patient survives an acute toxic exposure, most will develop some degree of nerve damage to the peripheral nerves (sensory and motor disturbances); many survivors may have cardiac, liver, renal, and skin problems; the prognosis is fair to poor. Chronic poisoning and organic arsenic exposure have better outcomes with fewer and less severe problems.

Arsenic Poisoning Part-4



Arsenic Poisoning Part-4

How is arsenic poisoning diagnosed?

The history of the patient is very important as exposures are most often from industrial accidents so other people (coworkers, rescue personnel) may be exposed and not realize they may have some risk also. People exposed to toxic levels of arsenic may have breath and urine that smells like garlic as a clue to their diagnosis. Most doctors that suspect arsenic (or other metal or metalloid poisonings) will request lab studies such as blood cell counts and serum electrolytes such as calcium and magnesium; if there is evidence of hemolysis (blood cell destruction), a type and screening for a potential blood transfusion is done.

 There are rapid urine "spot" tests available to diagnose elevated levels of arsenic, but they usually don't distinguish between organic and inorganic arsenic. The patient's blood and urine will be sent for analysis for arsenic; a result of > 50 micrograms/L is considered elevated, but acute toxic exposures may result in levels 5 to 100 times or more than those which are considered "elevated." A speciation test (determines levels of inorganic versus organic arsenic) is required in all cases in which total urine arsenic is elevated since inorganic arsenic is so toxic. Electrocardiograms (ECG, EKG) and nerve conduction tests are often done in any type of suspected arsenic exposure. Tests for other toxins or toxic overdoses (for example, Tylenol ingestion) may also be done.