Arm and Leg Fractures

Arm and leg fractures usually result from trauma and commonly cause substantial muscle, nerve, and other soft-tissue damage. The prognosis varies with the extent of disablement or deformity, the amount of tissue and vascular damage, the adequacy of reduction and immobilization, and the patient’s age, health, and nutritional status.
Children’s bones usually heal rapidly and without deformity. Bones of adults in poor health and with impaired circulation may never heal properly. Severe open fractures, especially of the femoral shaft, may cause substantial blood loss and life-threatening hypovolemic shock.
Causes
Most arm and leg fractures result from major trauma—for example, a fall on an outstretched arm, a skiing accident, or child abuse (shown by multiple or repeated episodes of fractures). However, in a person with a pathologic bone-weakening condition, such as osteoporosis, bone tumors, or metabolic disease, a mere cough or sneeze can also produce a fracture. Prolonged standing, walking, or running can cause stress fractures of the foot and ankle—usually in nurses, postal workers, soldiers, and joggers.
Signs and symptoms
Arm and leg fractures may produce any or all of the five Ps: pain and point tenderness, pallor, pulse loss, paresthesia, and paralysis. (The last three are distal to the fracture site.) Other signs include deformity, swelling, discoloration, crepitus, and loss of limb function. Numbness and tingling, mottled cyanosis, cool skin at the end of the extremity, and loss of pulses distal to the injury may indicate arterial compromise or nerve damage. Open fractures also produce an obvious skin wound.

Complications of arm and leg fractures include:
  • hypovolemic shock as a result of blood vessel damage (This is especially likely to develop in patients with a fractured femur.)
  • permanent deformity and dysfunction if bones fail to heal (nonunion) or heal improperly (malunion)
  • aseptic necrosis of bone segments from impaired circulation Continue reading “Arm and Leg Fractures”

Introduction to Glycogen storage disease

Consisting of at least eight distinct errors of metabolism—all inherited—glycogen storage disease alters the synthesis or degradation of glycogen, the form in which glucose is stored in the body.
Normally, muscle and liver cells store glycogen. Muscle glycogen is used in muscle contraction; liver glycogen can be converted into free glucose, which can then diffuse out of the liver cells to increase blood glucose levels.
Glycogen storage disease manifests as a dysfunction of the liver, heart, or musculoskeletal system. Symptoms vary from mild and easily controlled hypoglycemia to severe organ involvement that may lead to cardiac and respiratory failure.
Causes
Almost all glycogen storage disease (types I through V and type VII) is transmitted as autosomal recessive traits. (See Types of glycogen storage disease.) The mode of transmission of type VI is unknown; type VIII may be an X-linked trait.
The most common type of glycogen storage disease is type I, glucose-6-phosphatase deficiency, or von Gierke’s disease, which results from a deficiency of the liver enzyme glucose-6-phosphatase. It occurs in about 1 in 200,000 births, but the incidence may be higher in some populations. This enzyme converts glucose-6-phosphate into free glucose and is necessary for the release of stored glycogen and glucose into the bloodstream to relieve hypoglycemia.
Infants may die of acidosis before age 2; if they survive past this age, with proper treatment, they may grow normally and live to adulthood with only minimal hepatomegaly. Brief periods of fasting Continue reading “Introduction to Glycogen storage disease”

Hypovolemic shock

In hypovolemic shock, reduced intravascular blood volume causes circulatory dysfunction and inadequate tissue perfusion. Without sufficient blood or fluid replacement, hypovolemic shock syndrome may lead to irreversible cerebral and renal damage, cardiac arrest and, ultimately, death.  Hypovolemic shock requires early recognition of signs and symptoms and prompt, aggressive treatment to improve the prognosis.
Causes
Hypovolemic shock usually results from acute blood loss—about one-fifth of the total volume. Such massive blood loss may result from GI bleeding, internal hemorrhage (hemothorax and hemoperitoneum), or external hemorrhage (accidental or surgical trauma) or from any condition that reduces circulating intravascular plasma volume or other body fluids such as in severe burns. Other underlying causes of hypovolemic shock include intestinal obstruction, peritonitis, acute pancreatitis, ascites and dehydration from excessive perspiration, severe diarrhea or protracted vomiting, diabetes insipidus, diuresis, and inadequate fluid intake.
Signs and symptoms
Hypovolemic shock produces a syndrome of hypotension with narrowing pulse pressure; decreased sensorium; tachycardia; rapid, shallow respirations; reduced urine output; and cold, pale, clammy skin. Metabolic acidosis with an accumulation of lactic acid develops as a result of tissue anoxia as cellular metabolism shifts from aerobic to anaerobic pathways. Disseminated intravascular coagulation (DIC) is a possible complication of hypovolemic shock.
Diagnosis
No single symptom or diagnostic test establishes the diagnosis or severity of shock. Characteristic Continue reading “Hypovolemic shock”

Introduction to Glaucoma

Glaucoma is a group of disorders characterized by intraocular pressure (IOP) high enough to damage the optic nerve. If untreated, it leads to gradual peripheral vision loss and, ultimately, blindness.
Glaucoma occurs in several forms: chronic open-angle (primary), acute angle-closure, low tension (normal IOP that’s too high for a particular person), congenital (inherited as an autosomal recessive trait), and secondary to other causes.
Glaucoma is the second most common cause of blindness in the United States. About 2.5 million Americans are afflicted with the disease, but only 1 million know that they have it. Its incidence is highest among blacks, and it’s the single most common cause of blindness in that group. The visual prognosis is good with early treatment.
Causes
The cause of glaucoma varies according to the type of disorder:
  • Chronic open-angle glaucoma results from overproduction of aqueous humor or from obstructed outflow of aqueous humor through the trabecular meshwork or the canal of Schlemm. This form of glaucoma frequently runs in families and affects 90% of all patients with glaucoma.
  • Acute angle-closure (narrow-angle) glaucoma results from obstructed outflow of aqueous humor caused by anatomically narrow angles between the anterior iris and the posterior corneal surface, shallow anterior chambers, a thickened iris that causes angle closure on pupil dilation, or a bulging iris that presses on the trabeculae, closing the angle. Adhesions in the angle, referred to as peripheral anterior synechiae, may be the cause.
  • Secondary glaucoma can result from uveitis, trauma, or drugs such as steroids. Continue reading “Introduction to Glaucoma”

Acromegaly and Gigantism

Chronic, progressive diseases, acromegaly and gigantism are marked by hormonal dysfunction and startling skeletal overgrowth. Acromegaly occurs after epiphyseal closure, causing bone thickening and transverse growth and visceromegaly. Gigantism begins before epiphyseal closure and causes proportional overgrowth of all body tissues. Although the prognosis depends on the causative factor, these disorders usually reduce life expectancy unless treated in a timely way.
Causes
Typically, oversecretion of human growth hormone (HGH) produces changes throughout the entire body, resulting in acromegaly and, when oversecretion occurs before puberty, gigantism. Somatotrope adenomas and, rarely, extrapyradimal pituitary lesions or other tumors may cause this oversecretion, but the cause of the tumors themselves remains unclear. Elevated HGH levels in more than one family member suggest a genetic cause.
The earliest sign of acromegaly is soft-tissue swelling of the extremities, which causes coarsening of the facial features. This rare form of hyperpituitarism occurs equally among men and women, usually between ages 30 and 50.
Signs and symptoms
Acromegaly develops slowly, whereas gigantism develops abruptly.
Acromegaly
Acromegaly commonly produces hyperdidrosis, arthropathy, carpal tunnel syndrome, proximal muscle weakness and fatigue, acanthosis nigricans and skin tags, and oily skin.
Hypersecretion of HGH produces cartilaginous and connective tissue overgrowth, resulting in a Continue reading “Acromegaly and Gigantism”

Brief Summary of Abdominal Injuries

Blunt and penetrating abdominal injuries may damage major blood vessels as well as internal organs. Their most immediate life-threatening consequences are hemorrhage and hypovolemic shock; later threats include infection. The prognosis depends on the extent of the injury and on the organs damaged, but it’s generally improved by prompt diagnosis and surgical repair.
Causes
Blunt (nonpenetrating) abdominal injuries usually result from motor vehicle accidents, falls from heights, or athletic injuries; penetrating abdominal injuries, from stab or gunshot wounds.

Signs and symptoms
Depending on the degree of injury and the organs involved, signs and symptoms vary as follows:
  • Penetrating abdominal injuries cause obvious wounds. For example, gunshots commonly produce both entrance and exit wounds, with variable blood loss, pain, and tenderness. These injuries can cause pallor, cyanosis, tachycardia, shortness of breath, and hypotension.
  • Blunt abdominal injuries can cause severe pain (such pain may radiate beyond the abdomen, for example, to the shoulders), bruises, abrasions, contusions, and distention. They may also result in tenderness, abdominal splinting or rigidity, nausea, vomiting, Continue reading “Brief Summary of Abdominal Injuries”

Stomatitis and other oral infections

A common infection, stomatitis—inflammation of the oral mucosa—may extend to the buccal mucosa, lips, and palate. It may occur alone or as part of a systemic disease.
There are two main types: acute herpetic stomatitis and aphthous stomatitis. Acute herpetic stomatitis is common and mild. Aphthous stomatitis is common in young girls and female adolescents.
Acute herpetic stomatitis is usually short-lived and easily recognized; however, it may be severe and, in neonates, may be generalized and potentially fatal. Aphthous stomatitis usually heals spontaneously, without a scar, in 10 to 14 days.
Other oral infections include gingivitis, periodontitis, Vincent’s angina, and glossitis.

Causes
Acute herpetic stomatitis results from herpes simplex virus. The cause of aphthous stomatitis is unclear.
Signs and symptoms
Acute herpetic stomatitis begins with burning mouth pain. In immunocompromised individuals, reactivation of the herpes simplex virus infection may be frequent and severe. Gums are swollen and bleed easily, and the mucous membranes are extremely tender. Papulovesicular ulcers appear in the mouth and throat and eventually become punched-out lesions with reddened areolae. The small vesicles rupture and form scales. Another common finding is submaxillary Continue reading “Stomatitis and other oral infections”

Sideroblastic anemias

Sideroblastic anemias, a group of heterogenous disorders, produce a common defect—failure to use iron in hemoglobin (Hb) synthesis, despite the availability of adequate iron stores. These anemias may be hereditary or acquired; the acquired form, in turn, can be primary or secondary.
Hereditary sideroblastic anemia often responds to treatment with pyridoxine. Correction of the secondary acquired form depends on the causative disorder; the primary acquired (idiopathic) form, however, resists treatment and usually proves fatal within 10 years after onset of complications or a concomitant disease.
Causes
Hereditary sideroblastic anemia appears to be transmitted by X-linked inheritance, occurring mostly in young males; females are carriers and usually show no signs of this disorder.
The acquired form may be secondary to ingestion of, or exposure to, toxins, such as alcohol and lead, or to drugs, such as isoniazid and chloramphenicol. It can also occur as a complication of other diseases, such as rheumatoid arthritis, lupus erythematosus, multiple myeloma, tuberculosis, and severe infections.
The primary acquired form, known as refractory anemia with ringed sideroblasts, is most common Continue reading “Sideroblastic anemias”