Hyperammonemia is defined as an increase in the level of ammonia in the blood.
Ammonia is a normal constituent of all body fluids. The body excretes excess ammonia by excreting it as urea. Urea is synthesized in the liver by the urea cycle enzymes. The body gets ammonia by bacterial hydrolysis of urea and other nitrogenous compounds in the intestine, the purine nucleotide cycle and amino acid transamination in skeletal muscle and other metabolic processes in the kidneys and the liver. If ammonia accumulates in the blood, it can enter the brain and result in the neurological disorders associated with hyperammonemia.
Mechanisms of ammonia neurotoxicity at the molecular level have been proposed. Acute ammonia intoxication in an animal model is found to lead to increased extracellular concentration of glutamate in the brain and results in the activation of the N Methyl D Aspartate receptor. Activation of this receptor mediates ATP depletion and ammonia neurotoxicity. Sustained blocking of the NMDA receptor by continuous administration of antagonists like dizocilpine (MK 801) or memantine, prevents both phenomena leading to significantly increased survival time in rats. The ATP depletion is believed to be due to activation of the Na K ATPase which in turn is a consequence of decreased phosphorylation by protein kinase C. Activation of the NMDA receptor is probably the cause of seizures in acute hyperammonemia.
Other molecular features of disturbed neural function in hyperammonemia include downregulation of the gap junction channel connexin 43, the water channel aquaporin 4 genes and the astrocytic inward rectifier K channel genes colocalized to astrocytic end feet at the brain vasculature, where they regulate water and potassium t...
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...e of supportive treatment with lactulose, antibiotics, nutritional repletion and supportive care.
The diagnosis of hyperammonemia may be challenging and requires a high index of suspicion. However it should be considered when a clear cause of altered mental status is not obvious after basic investigations. As an initial step, it is advisable to exclude hypo or hyperglycemia, azotemia, liver failure, electrolyte imbalance, sepsis, structural and vascular pathologies like stroke and CNS involvement by cancers. Thereafter the evaluation can be expanded to consider less common etiologies. In terms of common presenting features, those that have been described tend to occur at a serum ammonia level of 1.5 times the upper limit of normal serum ammonia and include a spectrum of progressive lethargy, confusion, weakness, ataxia, agitation, seizure, stupor, coma and death.
The Mayo Clinic’s book on High Blood Pressure was full of detailed facts about blood pressure and what it is. This is extremely significant to the experiment because blood pressure is one of the variables being tested. Understanding blood pressure is one of the key components to receiving accurate results from this experiment. Most of the book is on high blood pressure, which is not necessary for the experiment, but the book still had plenty of useful information about blood pressure itself. The book explains that when the heart beats, a surge of blood is released from the left ventricle. It also tells of how arteries are blood vessels that move nutrients and oxygenated blood from the heart to the body’s tissues. The aorta, or the largest artery in the heart, is connected to the left ventricle and is the main place for blood to leave the heart as the aorta branches off into many different smaller
Homeostasis is the biological process that maintains a stable internal environment despite what occurs in the external environment. Chemicals and bodily functions are maintained in a balanced state so the body may function optimally. There are various systems in the human body that require maintenance through the processes of biochemical checks and balances so they may function properly. One of these systems includes the rise and fall of blood glucose and is under the control of the homeostatic regulation process. Homeostasis is essential in blood glucose regulation as high blood glucose levels (hyperglycaemia) and low blood glucose levels (hypoglycaemia) are dangerous and can affect the human body in many ways and can also lead
There are a series of nodes along the axon where there is a high concentration of sodium (Na+) and K+ channels. There is a high concentration of Na+ outside the cell and a high concentration of K+ inside the cell. As the nodes sen...
There is progressive vasoconstriction of arterioles until the BP exceeds the upper limit of auto regulation, followed by breakthrough vasodilation, increase in cerebral blood flow, blood-brain barrier dysfunction, and cerebral oedema(Rodriguez-Yanez et al., 2006). Cerebral ischemia results in severely ischemic tissue with failure of electrical activity and ionic pumps (Rodriguez-Yanez et al., 2006) There is increase in the release of the excitatory amino acid glutamate due to electrical failure. (Rodriguez-Yanez et al., 2006) . Glutamate receptors are activated as a result and cause the opening of ion channels that allow potassium ions to leave the cell and sodium and calcium ions to enter. This has a number of physiological effects.
Its ability to inhibit sodium channels within brain cells thereby protecting the cells from hypoxia (lack of oxygen)
The thyroid is the energy generator of the body. All of us experience fatigue at some time in our lives because of lack of sleep, overwork, or stress. For individuals with hypothyroidism, fatigue is a way of life. There never seems to be enough energy. But, you don’t have to feel this way. For those who suffer from hypothyroidism, there is HOPE.
When diagnosed with hyponatremia treatment usually immediately begins. Treatment must be a restriction of both salt and water (Gheorghita et. al 2010). Hyponatremic patients must receive a slow increase in sodium with a restriction of liquids. Intravenous hypertonic saline solution of 3% NaCl can be administered to patients who have been diagnosed with hyponatremia. There is a precise formula that is used in determining the quantity of NaCl that is used in increasing sodemia and the rate at which it should be administered (Gheorghita et. al 2010).
The thyroid is one of the most essential glands in the body. It is located in the endocrine system, and sits right in the neck just above where the collar bones meet. The thyroid gland functions to produce hormones that control how every cell in the body utilizes energy, also known as a process called metabolism. When a person's thyroid abnormally produces an excessive amount of thyroid hormones, this is a condition referred to as hyperthyroidism. The causes of hyperthyroidism are known to include: eating too much food with iodine, graves disease, inflammation due to viral infections, tumors of the testes and ovaries, taking a large amount of thyroid hormone, receiving medical imaging tests consisting of contrast dye iodine, and growth of thyroid or pituitary gland (Board "Hyperthyroidism"). With an overactive thyroid, the body tends to speed up its functions. Symptoms vary from, fast heartbeats, rapid weight loss, abnormal sweating, nervousness, and mood changes. Hyperthyroidism is normally diagnosed through a series of lab tests. If not properly taken care of, condition may worsen leading to bone and heart problems in the long run. As far as treatment is concerned, options may vary from person to person depending on age and the level of activity of the thyroid. Treatments include antithyroid medicines, radioactive iodine ablation, and the last resort, surgery. Though all treatment plans work, radioactive iodine ablation is a permanent and more reliable remedy for an overactive thyroid. Radioactive iodine ablation is in fact the most commonly used cure for people with hyperthyroidism problems in the US today. “The treatment has been around since 1942 and has been extensively used since the 1950's” ("Radioactive Iodine Treatment o...
Hypertension, also known as high blood pressure is a medical condition where the arteries are constantly experiencing high blood pressure due to the force exerted on the walls of the arteries as the heart pumps blood throughout the body.
Rothman, S.M.; & Olney, J.W. (1986). Glutamate and the pathophysiology of Hypoxic-Ischemic brain damage. Ann Neurol. 19; 105-111.
Patients in the Intensive Care Unit are at a high risk to develop delirium. It is one of the most common conditions encountered by the staff in an Intensive Care Unit. Delirium can be hyperactive or hypo active according to the patients’ behavior. Disorientation, agitation, hallucinations, or delusions are characteristics that may be observed in the patient with hyperactive delirium. Apathy, quietly confused, withdrawal, lethargy, and even total lack of responsiveness are all symptoms of hypoactive delirium. Some or all of these symptoms may occur at any time.
is characterized by “deterioration in the level of consciousness, with lethargy, decrease in arousal and headache. The timing of the development of cerebral edema is variable, within most cases occurring 4 to 12 hours after starting treatment. Several case reports showed the presence of cerebral edema before the initiation of therapy. A method of clinical diagnosis based on bedside evaluation of a neurological state in DKA have been developed” (Pandey).
The thyroid gland is part of the endocrine system, and it is controlled by the pituitary which is known as the “master gland” of the endocrine system. The pituitary controls the thyroid by producing Thyroid Stimulating Hormone (TSH) which stimulates the production of thyroid hormones. . The thyroid gland secretes two main hormones: Thyroxine (T4) and Tri-Iodothyronine (T3). These hormones increase metabolic rate, heat production, oxygen consumption, appetite, growth hormone secretion, alertness and quicker reflexes. The thyroid gland is located in the anterior portion of the neck, beneath the Adam’s apple. It is divided in two lobes on either side of the windpipe: right lobe and left lobe. These lobes create what looks like a butterfly shape. The gland is essential to the contribution of maintaining the homeostasis of the body. It plays a role in monitoring the body’s expenditure of energy and running the body’s metabolism.
Rationale: Therapeutic use of self by the nurse and concrete task definition and assignment reinforce positive coping strategies and allow caregivers to feel less guilty when tasks are delegated to multiple caregivers. Ackley and Ladwig p. 286
It is then secreted within the small intestine where it helps to break down ethanol, fats and other acidic wastes including ammonia, into harmless substances.