| Osteogenesis Imperfecta Posted: 17 Feb 2011 05:28 PM PST 
- Also known as brittle-bone disease.
- Is a genetic (inherited) disorder characterized by bones that break easily without a specific cause.
Etiology - People with the disease have an error (mutation) in the genetic instructions on how to make strong bones. As a result their bones break easily.
Pathophysiology - Can result from autosomal dominant or recessive inheritance.
- Mutation change occurs in the DNA (the genetic code) within a gene that makes collagen, a major component of the connective tissues in bones, ligaments, teeth, and the white outer tissue of the eyeballs (sclera).
- The reticulum fails to differentiate into mature collagen or causes abnormal collagen development.
- Leading to immature, coarse bone formation and cortical bone thinning.
- Result in fragile bones that break easily.
Signs and Symptoms - Multiple fractures at birth
- Bilaterally bulging skull
- Triangular shaped head and face
- Prominent eyes
- Blue or gray tinted sclera
- Pain and bone swelling
- Loss of function
- Thin, translucent skin
- Teeth that breaks easily
- Breathing problems
- Delayed walking
- Scoliosis as the child grows
- Tinnitus
- Hearing loss
- Kidney stone
- Urinary problems
Assessment - Family history and characteristics features such as blue sclera or deafness.
- Complete medical history and physical examination.
- Skin biopsy to determine the amount and structure of collagen.
- X-ray showing evidence of multiple old and new fractures and skeletal deformities.
- Eye examination to detect connective tissue problems of the eye.
- Bone Mineral Density (BMD) test
- Complete blood count
- Arthroscopy
- Bone biopsy.
Nursing Diagnoses - Pain
- Impaired physical mobility
- Risk for injury
- Risk for infection
- Self-care deficit
- Knowledge deficit
- Impaired gas exchange
- Anxiety
- Ineffective individual coping
Nursing Interventions - Support limbs, do not pull on arms or legs or lift the legs to prevent more fractures or deformities.
- Position the patient with care.
- Check the patient's circulatory, motor, and sensory abilities.
- Provide emergency care of fractures.
- Observe for signs of compartment syndrome.
- Encourage diet high in protein and vitamins to promote healing.
- Encourage fluids to prevent constipation, renal calculi, and urinary tract infection.
- Provide care for client with traction, with cast, or with open reduction.
- Encourage mobility when possible.
- Administer analgesics as prescribed.
- Teach the patient preventive measures.
- Monitor hearing needs.
- Aggressively teach all upper respiratory infections including colds.
Complications - Pressure ulcer
- Pneumonia
- Constipation
- Anorexia
- Urinary stasis
- Infection
- Hypovolemic shock
- Pathologic fracture
- Irreversible hearing loss
- Fat embolism
- Scoliosis
Related posts: - Fractures of Extremity
- Fracture Of The Hips
- Scoliosis
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| Trigeminal Neuralgia (Tic Douloureux) Posted: 17 Feb 2011 04:36 PM PST 
- Also known as prosopalgia.
- Is a neuropathic disorder characterized by intense pain in the eye, nose, ear, lips, jaw, scalp, forehead, cheeks, and alongside of the face. Some patients experience pain in the left index finger.
Etiology and Pathophysiology - Disorder of the fifth cranial (trigeminal) nerve characterized by excruciating knifelike pain along the branches of the nerve.
- Etiology is unknown.
- Incidence higher in women of middle age and older.
Signs and Symptoms - Burning or knifelike pain lasting 1 to 15 minutes, usually over the lip, chin, and in teeth.
- Pain precipitated by stimulation of trigger zones during activities such as brushing hair and eating when sitting in a cold draft.
- Sudden closure of an eye.
- Twitching of the mouth.
Assessment - Description of pain.
- Specific factors that trigger attacks.
- How condition affects behavior such as avoiding eating, shaving, washing the face, or brushing the teeth because of fear of precipitating the attack.
Nursing Diagnoses - Fear
- Risk for injury
- Pain
- Altered nutrition, less than body requirements
Therapeutic Interventions - Administer analgesics and antiepileptic drugs as ordered.
- Injection of alcohol into the ganglion to relieve pain for several months or years until the nerve generates.
- Surgical intervention requiring intracranial approach.
- Severing the sensory root of the nerve, which will cause loss of all sensation in the area supplied by the nerve.
- Microscopic relocation of arterial loop that may cause vascular compression of the trigeminal nerve.
- Percutaneous radio frequency trigeminal gangliolysis.
Nursing Interventions - Instruct the client to avoid factors that can trigger the attack and result in exhaustion and fatigue.
- Avoid foods that are too cold or too hot.
- Chew foods in the affected side.
- Use cotton pads gently, wash face and for oral hygiene.
- Provide teaching to clients who have sensory loss as a result of a treatment.
- Inspection of the eye for foreign bodies, which the client will not be able to feel, should be done several times a day.
- Warm normal saline irrigation of the affected eye two to three times a day is helpful in preventing corneal infection.
- Dental check ups every 6 months is encouraged, since dental caries will not produce pain.
- Explain to the client and his family the disease and its treatments.
Related posts: - Head-To-Toe Assessment (B. Face)
- Head-To-Toe Assessment N. Cranial Nerve I (olfactory Nerve)
- Amputation
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| Respiratory Patterns Posted: 16 Feb 2011 05:10 PM PST 
Respiration Oxygen reaches the body cells and carbon dioxide is removed from the cells through respiration. Respiration involves two processes which is the external respiration and the internal respiration. The External respiration is the movement of air between the environment and the lungs while internal respiration is the movement of oxygen between the hemoglobin and single cells. External respiration involves the following interrelated processes: - Ventilation. It is the mechanical movement of air to and from the lungs and the exchange of respiratory gases.
- Conduction. It is the movement of air through the airways of the lungs.
- Diffusion. It is the movement of oxygen and carbon dioxide between the alveoli and red blood cells.
- Perfusion. It is the distribution of blood through pulmonary capillaries.
Abnormal Respiratory Patterns - Cheyne-stokes respiration – respiratory rhythm is irregular, characterized by alternating periods of apnea and hyperventilation. Respiratory cycle begins with slow, shallow breaths that gradually increase to abnormal depth and rigidity. Gradually, breathing slow and becomes shallower, climaxing in 10-20 second period of apnea before respiration resumes.
- Kussmaul's respirations – respirations are abnormally deep but regular, similar to hyperventilation. Rate is increased.
- Biot's respirations – condition of CNS causes shallow breathing interrupted by irregular periods of apnea.
- Orthopnea – a respiratory condition in which a person must sit or stand to breathe deeply or comfortably.
- Dyspnea – difficulty breathing.
Normal Respiratory Rates by Age | Age Group | Respiratory Rate | Age Group | Respiratory Rate | | Newborn | 35 cpm* | 10 years | 19 cpm | | 1-11 months | 30 cpm | 12 years | 19 cpm | | 2 years | 25 cpm | 14 years | 18 cpm | | 4 years | 23 cpm | 16 years | 17 cpm | | 6 years | 21 cpm | 18 years | 16-18 cpm | | 8 years | 20 cpm | Adult | 12-20 cpm |
* cpm – cycles per minute (From Fundamentals of Nursing by Potter and Perry) Factors Affecting the Character of Respiration - Exercise. This activity increases the rate and the depth of respiration to meet the body's greater need for oxygen.
- Acute pain. When a person is in pain, the rate and the depth of respiration increases as a result of sympathetic stimulation.
- Anxiety. Anxiety increases the rate and the depth of respiration as a result of sympathetic stimulation.
- Smoking. Long-term smoking changes the lung's airways which results to an in increase in respiratory rate.
- Body position. When a person is in straight and erect posture, full chest expansion is promoted. A stooped or slumped position impairs ventilatory movement.
- Medications. Narcotics and sedatives depress the rate and depth of respiration while amphetamines and cocaine increases the arte and depth.
- Brainstem injury. Injury to the brainstem impairs the respiratory center and inhibits respiratory rate and rhythm.
Related posts: - Neonatal Respiratory Adaptation Processes
- Nursing Diagnosis for Respiratory Diseases
- Severe Acute Respiratory Syndrome (SARS)
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| Difference between Placenta Previa and Abruptio Placenta Posted: 16 Feb 2011 05:00 PM PST 
| Difference Between Placenta Previa and Abruption Placenta | | Category | Placenta Previa | Abruptio Placenta | | Problem | Low implantation of the placenta | Premature separation of the placenta | | Incidence | It occurs in approximately 5 in every 1000 pregnancies | It occurs in about 10% of pregnancies and is the most common cause of perinatal death. | | Bleeding | Always present | May or may not be present | | Color of blood in bleeding episodes | Bright red | Dark red | | Pain during bleeding | Painless | Sharp, stabbing pain | | Management | - Bed rest (side lying position)
- NO vaginal or pelvic examinations
- Assessment of FHR and bleeding
- Lateral position
- No vaginal or pelvic examinations
- Termination of pregnancy
| |
Placenta Previa Placenta previa is the low implantation of the placenta. The types of placenta previa are the following: - Low-lying placenta previa – the implantation took place in the lower portion rather than the upper portion of the uterus.
- Marginal placenta previa – the placental edges are approaching the cervical os.
- Partial placenta previa – a portion of cerval os is occluded by the placental portion.
- Total placenta previa – implantation that totally obstructs the cervical os.
Incidence - It occurs in approximately 5 in every 1000 pregnancies
Risk factors - Increased parity
- Advanced maternal age
- Past cesarean births
- Past uterine curettage
- Multiple gestation
Signs and Symptoms - Bleeding – bright red blood. The lower uterine segment begins to differentiate with the upper segment later in pregnancy. Placenta has the inability to stretch to accommodate the differeing shape of the lower uterine segment or the cervix, thus, abrupt and bright red bleeding occurs.
- Painless bleeding
- Sudden bleeding
Therapeutic Management - Place the woman immediately on bed rest in a side-lying position.
- Weight perineal pads.
- NEVER attempt a pelvic or rectal examination because it may initiate massive blood loss.
Abruptio Placenta In this condition, the placenta has been implanted correctly, however the placenta separates prematurely. Incidence - It occurs in about 10% of pregnancies and is the most common cause of perinatal death.
Risk factors - High parity
- Advanced maternal age
- A short umbilical cord
- Chronic hypertensive disease
- Pregnancy-induced hypertension
- Direct trauma
- Vasoconstriction from cigarette use
- Thrombophilitic conditions that lead to thrombosis such as autoimmune antibodies
Signs and symptoms - Sharp, stabbing pain high in the uterine fundus (during initial separation)
- Tenderness felt on uterine palpation
- Heavy bleeding (not readily apparent). Blood can either pool under the placenta and be hidden from view. External bleeding is only present if the placenta separates first at the edges and blood escapes freely from the cervix.
- Hard, boardlike uterus with no apparent or minimally apparent bleeding
- Dark red blood (in bleeding episodes)
Management - Fluid replacement
- Oxygen by mask
- Monitor FHR
- Keep the woman in a lateral position
- DO NOT perform any vaginal or pelvic examinations or give enema
- Pregnancy must be terminated because the fetus cannot obtain adequate oxygen and nutrients. If birth does not seem imminent, cesarean birth is method of choice for delivery.
Related posts: - Placenta Previa
- Nursing Care Plan – Placenta Previa
- Placenta Previa Case Study
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| Alcohol Detoxification Posted: 15 Feb 2011 07:35 PM PST 
Definition Alcohol detoxification is the removal of alcohol from the body of an individual who is alcohol dependent or alcoholic. It is the abrupt cessation of alcohol intake coupled with the substitution of alcohol with drugs used to prevent alcohol withdrawal. Alcohol detoxification is not possible without support from friends and family. Most of all it needs a commitment on the part of the individual who will undergo detoxification to abstain from alcohol use. Alcohol Detoxification Process The process of alcohol detoxification requires that alcohol be eliminated from the human body and that any withdrawal or other symptoms that are bound to occur are treated medically or psychologically or both. As mentioned earlier, the detoxification process is largely determined by the alcoholic himself. The detoxification process is determined by the person's condition and by his approach. In some cases, patients who undergo the alcohol detoxification process may suffer from hallucinations, delirium tremens and convulsions, which require immediate attention and treatment. To minimize these symptoms, medical drugs are given. However, the administration of these medications has to be monitored and accurately controlled. Usually such medications have are given at high dosages initially, but is gradually tampered down over a week. Withdrawal symptoms can be quite distressing and can even become fatal if the addiction to alcohol is very severe. Safe withdrawal is accomplished with the administration of benzodiazepines to suppress the withdrawal symptoms. Drugs under this category are: - Chlordiaxepoxide (Librium) – is the benzodiazepine of choice in uncomplicated alcohol withdrawal due to its long half-life.
- Diazepam (Valium) – is available as an injection for patients who cannot safely take medications by mouth.
- Lorazepam (Ativan) – is available as an injection for patients who cannot safely take medications by mouth. This is also indicated in patients with impaired liver function because they are metabolized outside of the liver.
The most common drugs used for alcohol detoxification are benzodiazepines, with Chlordiazepoxide being the most preferred benzodiazepine used. Diazepam is also widely used, but fatal effects may occur if it is mixed with huge doses of alcohol. Hence, supervision is necessary for use of diazepam as a detoxifier. Where is alcohol detoxification done? In most cases, alcohol detoxification can be done at home. This is applicable when the alcohol consumption is just moderate. However, in cases where hallucinations, severe withdrawal symptoms and multi-substance misuse are noted, an inpatient detoxification is required. Related posts: - Alcohol Abuse
- Disorganized Schizophrenia
- Catatonic Schizophrenia
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| Disseminated Intravascular Coagulation (DIC) Posted: 15 Feb 2011 07:32 PM PST 
Definition Disseminated intravascular coagulation (DIC) is a condition in which blood clots form throughout the body’s small blood vessels. It is an acquired disorder of blood clotting that result from excessive trauma or similar underlying stimulus. These blood clots can reduce or block blood flow through the blood vessels, which can damage the body’s organs. Frequency - DIC occurs in approximately 1% of all hospitalized patients.
- It affects both sexes equally.
- No age predilection is known.
Causes Disseminated intravascular coagulation occurs in the following conditions: - Cancer especially certain types of leukemia
- Abruption placenta
- Pre-eclampsia
- Amniotic fluid embolism
- Trauma and burns
- Extensive surgery
- Infection in the blood by bacteria or fungus or sepsis
- Severe liver disease
- Severe tissue injury as in burns and head injury
Physiology of blood clotting Normal blood clotting is a balance between the clotting or hemostatic system and the fibrinolytic or the dissolving system of the bloodstream. When a blood vessel is injured, excessive blood loss is prevented by rapid occurrence of local vasoconstriction at the site of trauma or injury. As the vessel wall is torn, collagen located beneath the skin is released and exposed. As a result, platelets swell and become adherent and are irregularly shaped. Adenosine diphosphate is then released and attracts additional platelets and binds these platelets together, a process known as platelet aggregation. A platelet plug then seals the injured vessel as a result of the aggregation. To prevent blood from passing through the platelet plug, it is strengthened by fibrin threads. This is how blood clotting occurs. However, to prevent too much clotting, a proteolytic enzyme formed from plasminogen known as plasmin or fibrinolysin digests the fibrin threads that are present. This causes the lysis of the clot along with consumption of blood clotting factors. The fibrin degradation products prevent the production of more fibrin and platelet aggregation, thus normal blood clotting occurs. In summary, normal blood clotting occurs as a result of the balance between the clotting and dissolving system. Too much hemostatic system would pose negative effects to the body. Excessive fibrinolytic activity taking place in a human body would also result to massive blood loss. Pathophysiology In disseminated intravascular coagulation (DIC), there is an imbalance between the clotting and the dissolving activities. Extreme clotting takes place because of a damage that begins at one point in the circulatory system. This damage depletes the availability of the clotting factors such as the platelets and fibrin from the general circulation. Signs and symptoms - Bleeding on multiple sites in the body. Uncontrolled bleeding from puncture sites from injections or IV therapy.
- Blood clots. Ecchymoses and petechiae form on the skin.
- Drop in blood pressure
- Sudden bruising
- The toes and fingers are pale, cyanotic or mottled and feels cold
Laboratory results with DIC - Thrombocytopenia
- Large platelets on the blood smear
- Prolonged prothrombin and partial thromboplastin times
- Markedly low serum fibrinogen levels
- Elevated fibrin splits
Management - IV administration of heparin.
- Blood transfusion (for blood loss)
- Treat underlying disease condition
image courtesy of biomoz.com Related posts: - Thrombin Time Test
- Nursing Care Plan – Hemophilia
- Parahemophilia (Factor V Deficiency)
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| Pathophysiology of Cancer Posted: 13 Feb 2011 07:49 PM PST 
Definition of Cancer Cancer is disease of regulation of tissue growth. In this disease, the cells of the body display uncontrolled growth, invasion that intrudes and destroys adjacent tissues and spreads to other body locations. In order for a normal cell to transform into a cancer cell, genes which regulate cell growth and differentiation must be altered. Theories about Cancer - Cellular transformation and Derangement theory. In this theory, exposure of normal cells to some etiologic agent may transform normal cells into cancer cells.
- Failure of the Immune Response Theory. This theory conceptualizes that all individuals possess cancer cells but these cancer cells are NOT recognized by the immune system. Thus, cancer cells undergo destruction. Failure of the immune response system to kill or destroy the cancer cells leads to cancer.
Etiologic Factors or Carcinogens - Viruses or Oncogenic Viruses. Prolonged and recurrent viral infections may lead to the breakdown of the immune system. The overwhelmed immune system may fail to destroy the cancer cells present in the body. The human papillomavirus (HPV) are particularly common cancer-causing virus which is well-known for causing genital warts and all cases of cervical cancer.
- Chemical carcinogens. These chemicals cause cell mutation or alter the cell enzymes and proteins.
Industrial Compounds - Vinyl chloride – plastic manufacture, asbestos factories, construction works
- Polycyclic aromatic hydrocarbons
- Fertilizers
- Weed killers
- Dyes – analine dyes (most commonly found in beauty shops and used at homes), hair bleach
- Drugs – cytotoxic drugs, tar nicotine in tobacco, alcohol
Hormones - Estrogen
- Diethystilbesterol (DES)
Foods, preservatives - Nitrites in bacon or smoked meat
- Talc (polished rice, salami and chewing gum)
- Food sweeteners
- Nitrosomines (rubber baby nipples)
- Aflatoxins (mold in nuts, grains, milk, cheese and peanut butter)
- Polycyclic hydrocarbons
Radiation - From x-rays or radioactive isotopes
- From sunlight or UV rays
Physical irritation or trauma - Pipe smoking
- Multiple deliveries
Risk Factors - Older individuals
- Women are more prone to breast, uterine and cervical cancer
- Men are more prone prostate and lung cancer
- Urban dwellers
- Chemical factory workers
- Farmers
- Personnel of radiology department
- Family history
- Obesity
- Stress
Pathophysiology of Cancer A healthy cell becomes a cancer cell by undergoing the following processes: - Proto-oncogenes are changed to oncogenes. Proto-oncogenes are genes that are coded to maintain normal cell growth. In cases of a developing cancer, oncogene takes its place. Oncogene is a gene that makes cells grow and divide rapidly.
- Cancer cell grows and divides rapidly.
- Alteration of the tumor suppression genes takes place.
- DNA repair genes are altered and turned off.
image courtesy of csuohio.edu Related posts: - Stomach Cancer (Gastric Cancer)
- Pathophysiology of AIDS/HIV
- Chemotherapy Effects
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| Sodium Bicarbonate Nursing Responsibilities Posted: 13 Feb 2011 07:34 PM PST 
Information on Sodium Bicarbonate Brand Name: Bakin Soda, Bell-Ans, Citrocarbonate, Neut, Soda Mint Classification: antiulcer agents, alkalinizing agent Indications - Management of metabolic acidosis
- Used to alkalinize urine and promote excretion of certain drugs in over dosage situations
- Used as an antacid
Action Sodium Bicarbonate acts as an alkalinizing agent by releasing bicarbonate ions. Following oral administration of this medication, it releases bicarbonate which is capable of neutralizing gastric acid. Contraindication - Metabolic or respiratory alkalosis
- Hypocalcemia
- Excessive chloride loss
- It is not recommended as an antidote following ingestion of strong mineral acids
- Patients on sodium restricted diet
- Renal failure
- Severe abdominal pain of unknown cause especially if associated with fever
Used cautiously in patients with: - Congenital heart failure
- Concurrent corticosteroid therapy
- Children with diabetic ketoacidosis because taking sodium bicarbonate may increase the risk of cerebral edema
- Chronis use as an antacid because it may result to metabolic alkalosis and possible sodium overload
Side effects - Edema
- Flatulence
- Gastric distention
- Metabolic alkalosis
- Hypernatremia
- Hypocalcemia
- Hypokalemia
- Sodium and water retention
- Irritation at IV site
- Tetany
Nursing Responsibilities - Assess the client's fluid balance throughout the therapy. This assessment includes intake and output, daily weight, edema and lung sounds.
- Symptoms of fluid overload should be reported such as hypertension, edema, difficulty breathing or dyspnea, rales or crackles and frothy sputum.
- Sigs of acidosis should be assessed such as disorientation, headache, weakness, dyspnea and hyperventilation.
- Assess for alkalosis by monitoring the client for confusion, irritability, paresthesia, tetany and altered breathing pattern.
- Hypernatremia clinical manifestations should be assessed and monitored which includes: edema, weight gain, hypertension, tachycardia, fever, flushed skin and mental irritability.
- Hypokalemia should also be assessed by monitoring signs and symptoms such as: weakness, fatigue, U wave on ECG, arrhythmias, polyuria and polydipsia.
- IV sites should be observed closely. Extravasation should be avoided as tissue irritation or cellulitis may occur when taking sodium bicarbonate.
- If infiltration occurs, the physician should be notified immediately. Confer with the doctor or other health care staff regarding warm compresses and infiltration site with lidocaine or hyaluronidase.
- Monitor the client's serum calcium, sodium, potassium, bicarbonate concentrations, serum osmolarity, acid-base balance and renal function before and throughout the therapy.
- Tablets must be taken with a full glass of water.
- For clients taking the medication as a treatment for peptic ulcers it may be administered 1 and 3 hours after meals and at bedtime.
Related posts: - Serum Sodium Normal Values
- Fluid and Electrolyte Imbalance: Hyponatremia
- DICLOFENAC SODIUM
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| Lead Poisoning Posted: 12 Feb 2011 09:45 PM PST 
Definition  lead in chips from old paints Lead poisoning, also called Plumbism or painter's colic, is a condition caused by an increased level of heavy metal lead in the body. The heavy metal, lead, is a very strong poison. When an individual swallows a lead object or breathes in lead dust, some of the poison can stay in the body and cause serious health problems. When can you say that a child has been poisoned with lead? Lead poisoning is usually said to be present when the child has two successive blood lead levels greater than 10 ug/dl. Where can lead be found? Lead can be found on various places and in different things especially on old houses. Most commonly lead can be found in the following places: - House paints before 1978. Small children often swallow paint chips or dust from lead-based paint that results to plumbism.
- Gasoline
- Storage batteries
- Pewter pitcher and dinnerware
- Soil contaminated by decades of car exhaust or years of house paint scrapings. Lead is more common in soil near highways and houses.
- Old toys and furniture that are painted before 1976
- Painted toys and decorations with unknown place of production.
- Lead bullets, fishing sinkers and curtain weights
- Plumbing pipes and faucets. Nowadays new building code required a lead-free solder. However, lead is still found in some modern faucets that may result to the presence of lead in drinking water in homes.
Methods of Screening - Serum ferritin. This is the most widely used screening method in determining blood lead levels. However, this test requires the use of atomic absorption spectrophotometry, which is a costly procedure.
- Erythrocyte protoporphyrin test. This is a free and simple screening method that only involves a fingerstick. Protoporphyrin is elevated in children with lead poisoning as lead blocks protoporphyrin from entering the heme portion of the blood component.
- Radiograph. A radiograph of the abdomen may reveal paint chips in the intestinal tract.
Management and Prevention of lead poisoning - Remove the child from the environemtn containing lead or removal of the source of lead from the child's environment.
- The walls must be covered with a paneling or Masonite.
- For children with lead level greater than 20 ug/dl, an oral chelating agent such as Succimer may be prescribed.
- Keep the home dust-free as possible.
- Have everyone wash their hands before eating.
- Water should be tested for lead. When tested positive, containing high levels of lead, consider installing an effective filtering device or switch to bottled water for drinking and cooking
- Avoid canned goods from foreign countries.
- Throw out old painted toys if you do not know whether the paint contains lead.
image courtesy of fotosearch.com Related posts: - Staphylococcal Food Poisoning
- Common Concerns During Infancy: Safety
- Chelation Therapy
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| Nonshivering Thermogenesis Posted: 12 Feb 2011 09:20 PM PST 
Definition The word thermogenesis means the process of heat production in organisms. When adults are cold, they shiver. Shivering results to increased muscle activity, thus, producing heat. In newborns these mechanisms of heat production do not occur. Newborns rarely shiver except at very low temperatures. Shivering is not an effective way of producing heat in the youngest population. Nonshivering thermogenesis is the primary method of heat production in infants. It is NOT shivering that produces heat but the metabolism of brown fat increases body temperature when the thermal receptors in the skin detect a skin temperature of 35 to 36 degree Celsius (95 to 96.8 degree Fahrenheit). Brown Fat  location of brown fats in newborns Brown fat, also called adipose tissue or brown adipose tissue (BAT), is a special kind of highly vascular fat found in newborns. It contains an ample supply of blood vessels which cause the brown color. Brown fats are located primarily in the following areas: - Back of the neck
- In the axillae
- Around the kidneys
- Adrenals
- Sternum
- Between the scapulae
- Along the abdominal aorta
Some infants have insufficient brown fat stores. Preterm infants may be born before the stores of brown fat have accumulated. Aside from the said case, intrauterine growth restriction also deplete brown fat stores before birth occurs. Newborns that are exposed to prolonged cold stress may have insufficient brown fat stores as large amount brown fat is consumed for heat production in this situation. Thus, these infants will not be able to raise their body temperature if they are subjected to further episodes of cold stress. Without brown fat to be metabolized, no heat production will counteract the cold stress. Hence, the infant is at risk to serious complications. Processes Involved in Nonshivering Thermogenesis - Nonshivering thermogenesis begins when the thermal receptors in the skin detect a skin temperature of 35 to 36 degrees Celsius (95 to 96.8 degrees Fahrenheit).
- The thermal receptors stimulation is then transmitted to the hypothalamus thermal center.
- In response to the hypothalamic stimulation, norepinephrine is released in brown fat.
- Presence of norepinephrine in the brown fat initiates its metabolism.
- As brown fat is metabolized, it generates more heat than other fats.
- Thus, blood passing through the brown fats is warmed and carries heat to the systemic circulation or to the rest of the body.
image courtesy of thehealthblog.net Related posts: - Cold Stress in Newborns
- Methods of Heat Loss in Newborns
- VITAL SIGNS2
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