INTRAVENOUS INFUSION OF FLUIDS

 

INTRODUCTION: When fluid output exceeds fluid intake, volume deficits may result. Shock, dehydration, or electrolyte loss may occur; large deficits are fatal, unless treated. The following are some common reasons for fluid depletion: 

1) Loss of gastrointestinal (GI) fluids due to vomiting, diarrhea, chronic laxative use, or GI suctioning. 

2) Excessive sweating during hot weather, athletic activity, or prolonged fever. 

3) Severe burns. 

4) Hemorrhage. 

5) Excessive diuresis due to diuretic therapy or uncontrolled diabetic ketoacidosis.

PURPOSE OF ADMINISTERING IV FLUIDS: The immediate goal in treating a volume deficit disorder is to replace the depleted fluid. In non-acute circumstances, this may be achieved by drinking more liquids or by administering fluids via a feeding tube. In acute situations, IV fluid therapy is indicated. Regardless of the route, careful attention must be paid to restoring normal levels of blood elements and electrolytes as well as fluid volume. IV replacement fluids are of two basic types namely; crystalloids and colloids.

CRYSTALLOIDS: Crystalloids are IV solutions that contain electrolytes and other substances that closely mimic the body’s ECF. They are used to replace depleted fluids and to promote urine output. Crystalloid solutions are capable of quickly diffusing across membranes, leaving the plasma and entering the interstitial fluid and ICF. It is estimated that two thirds of infused crystalloids will distribute in the interstitial space.

COMPONENTS OF IV FLUIDS: Isotonic, hypotonic, and hypertonic solutions are available for that purpose. Sodium is the most common crystalloid added to solutions. Some crystalloids contain dextrose, a form of glucose, commonly in concentrations of 2.5%, 5%, or 10%. Dextrose is added to provide nutritional value: 1 L of 5% dextrose supplies 170 calories. In addition, water is formed during the metabolism of dextrose, enhancing the rehydration of the patient. When dextrose is infused, it is metabolized, and the solution becomes hypotonic.

EFFECTS OF IV FLUIDS: Infusion of crystalloids will increase total fluid volume in the body, but the compartment that is most expanded depends on the solute in this case, sodium, concentration of the fluid administered. Isotonic crystalloids can expand the circulating intravascular (plasma) fluid volume without causing major fluid shifts between compartments. Isotonic crystalloids such as normal saline are often used to treat fluid loss due to vomiting, diarrhea, or surgical procedures, especially when the blood pressure is low.

Because isotonic crystalloids can rapidly expand circulating blood volume, care must be taken not to cause fluid overload in the patient. Infusion of hypertonic crystalloids expands plasma volume by drawing water away from the cells and tissues.

RELATED;

1.  PLASMA VOLUME EXPANDERS

2.  BODY FLUIDS

3.  ANATOMY AND PHYSIOLOGY

REFERENCES

NICOTINE

INTRODUCTION:  Nicotine is sometimes considered a CNS stimulant, and although it does increase alertness, its actions and long-term consequences place it in a class by itself. Nicotine is unique among abused substances in that it is legal, strongly addictive, and highly carcinogenic. Furthermore, use of tobacco can cause harmful effects to those in the immediate area who breathe secondhand smoke.  Patients often do not consider tobacco use as substance abuse. 

Tobacco Use and Nicotine: The most common method by which nicotine enters the body is through the inhalation of cigarette, pipe, or cigar smoke. Tobacco smoke contains more than 1,000 chemicals, a significant number of which are carcinogens. The primary addictive substance present in cigarette smoke is nicotine. Effects of inhaled nicotine may last from 30 minutes to several hours. Nicotine affects many body systems including the nervous, cardiovascular, and endocrine systems. 

Pharmacodynamics:  Nicotine stimulates the CNS directly, causing increased alertness and ability to focus, feelings of relaxation, and light-headedness. The cardiovascular effects of nicotine include an accelerated heart rate and increased blood pressure, caused by activation of nicotinic receptors located throughout the autonomic nervous system.

These cardiovascular effects can be particularly serious in patients taking oral contraceptives: The risk of a fatal heart attack is five times greater in smokers than in nonsmokers. Muscular tremors may occur with moderate doses of nicotine, and convulsions may result from very high doses. Nicotine affects the endocrine system by increasing the basal metabolic rate, leading to weight loss. Nicotine also reduces appetite. Chronic smoking leads to bronchitis, emphysema, and lung cancer. Both psychological and physical dependence occur relatively quickly with nicotine. Dependence

Once started on tobacco, patient tend to continue their drug use for many years, despite overwhelming medical evidence that the quality of life will be adversely affected and their life span shortened. Discontinuation results in agitation, weight gain, anxiety, headache, and an extreme craving for the drug.  Although nicotine replacement patches and gum assist patients in dealing with the unpleasant withdrawal symptoms, only 25% of patients who attempt to stop smoking remain tobacco-free a year later.

RELATED;

1.  CAFFEINE  

2.  DEPENDENCE AND WITHDRAWAL SYNDROME

3.  BIOCHEMISTRY

REFERENCES

BREAST EXAMINATION

OBJECTIVES OF THE DISCUSSION:  By the end of this discussion, the reader/learner/medical student will be able to;

1.  List the importance of conducting breast examination

2.  Describe the normal findings that follows breast examination

3.  Explain the possible abnormal finding that can follow breast examination

INTRODUCTION: The breast examination by a physician remains the best means of early detection of breast cancer when combined with appropriately scheduled mammography. The results of the breast examination may be expressed by description or diagram, or both, usually with reference to the quadrants and tail region of the breast or by allusion to the breast as a clock face with the nipple at the center.

INSPECTION OF THE BREASTS: The breasts are first examined by inspection, with the patient’s arms at her sides, and then with her hands pressed against her hips, and/or with her arms raised over her head. If the patient’s breasts are especially large and pendulous, she may be asked to lean forward so that the breasts hang free of the chest, facilitating inspection.

FINDINGS: Tumors often distort the relations of these tissues, causing disruption of the shape, contour, and symmetry of the breast or position of the nipple. Some asymmetry of the breasts is common, but marked differences or recent changes deserve further evaluation.

1. Discolorations or ulcerations of the skin of the breast, areola, or nipple, or edema of the lymphatics that causes a leathery puckered appearance of the skin are abnormal.

2. A clear or milky breast discharge is usually bilateral and associated with stimulation or elevated prolactin levels also medically termed galactorrhea.

3. Bloody discharge from the breast is abnormal and usually unilateral; it usually does not represent carcinoma, but rather inflammation of a breast structure with intraductal papilloma is often found. Evaluation is necessary to exclude malignancy.

4. Pus usually indicates infection, although an underlying tumor may be encountered.

PALPATION OF THE BREASTS: Palpation follows inspection, first with the patient’s arms at her sides and then with the arms raised over her head. This part of the examination is usually done with the patient in the supine position. The patient may also be seated, with her arm resting on the examiner’s shoulder or over her head, for examination of the most lateral aspects of the axilla. Palpation should be done with slow, careful maneuvers, using the flat part of the fingers rather than the tips. The fingers are moved up and down in a wavelike motion, moving the tissues under them back and forth, so that any breast masses that are present can be more easily felt.

FINDINGS: If masses are found, their size, shape, consistency, and mobility as well as their position should be determined. Women with large breasts may have a firm ridge of tissue located transversely along the lower edge of the breast. This is the inframammary ridge and is a normal finding. The examination is concluded with gentle pressure inward and then upward at the sides of the areola to express fluid. If fluid is noted on inspection or is expressed, it should be sent for culture and sensitivity investigations.

RELATED;

1.  PELVIC INFLAMMATORY DISEASE

2.  OXYTOCIN

3.  OVULATION AND MENSTRUAL CYCLE

REFERENCES

LUNG CANCER

 

INTRODUCTION: Lung cancers arise from a single transformed epithelial cell in the tracheobronchial airways. A carcinogen such as; cigarette smoke, radon gas and other occupational and environmental agents, damages the cell, causing abnormal growth and development into a malignant tumor. Most lung cancers are classified into one of two major categories: small cell lung cancer which contribute 15% to 20% of tumors, and non–small cell lung cancer that contribute approximately 80% of tumors. Most small cell cancers arise in the major bronchi and spread by infiltration along the bronchial wall.

RISK FACTORS OF LUNG CANCER: Risk factors include tobacco smoke and especially second-hand also known as passive smoke, environmental and occupational exposures, gender, genetics, and dietary deficits. Other factors that have been associated with lung cancer include genetic predisposition and underlying respiratory diseases, such as chronic obstructive pulmonary disease (COPD) and tuberculosis (TB).

CLINICAL MANIFESTATIONS: Lung cancer often develops insidiously and is asymptomatic until late in its course. Signs and symptoms depend on location, tumor size, degree of obstruction, and existence of metastases to regional or distant sites.

1.  Most common symptom is cough or change in a chronic cough.

2.  Dyspnea may occur early in the disease.

3.  Hemoptysis or blood-tinged sputum may be expectorated.

4.  Chest pain or shoulder pain may indicate chest wall or pleural involvement. Pain is a late symptom and may be related to bone metastasis.

5.  Recurring fever may be an early symptom.

Chest pain, tightness, hoarseness, dysphagia, head and neck edema, and symptoms of pleural or pericardial infusion exist if the tumor spreads to adjacent structures and lymph nodes.  Common sites of metastases are lymph nodes, bone, brain, contralateral lung, adrenal glands, and liver.  Weakness, anorexia, and weight loss may appear.

ASSESSMENT AND DIAGNOSTIC METHODS: Chest x-ray, CT scans, bone scans, abdominal scans, PET scans, liver ultrasound, and MRI.  Sputum examinations, fiberoptic bronchoscopy, transthoracic fine-needle aspiration, endoscopy with esophageal ultrasound, mediastinoscopy or mediastinotomy, and biopsy.  Pulmonary function tests, ABG analysis scans, and exercise testing.  Staging of the tumor refers to the size of the tumor, its location, whether lymph nodes are involved, and whether the cancer has spread.

MEDICAL MANAGEMENT: The objective of management is to provide a cure if possible. Treatment depends on cell type, stage of the disease, and physiologic status. Treatment may involve surgery, radiation therapy, or chemotherapy—or a combination of these.

RELATED;

1.  THE ORIGIN OF CANCER

2.  GASEOUS EXCHANGE

3.  ACIDITY AND ALKALINITY OF BODY SYSTEMS

REFERENCES

DYNAMICS OF DRUGS AND THE HUMAN BODY

 

DYNAMICS OF DRUGS IN THE HUMA BODY:  Today we are living in a drug World where in more than 99% of medical interventions, there will be introduction of a given drug with an intention to cure the underlying disease.  Day to day, drugs are increasingly becoming available to us in big numbers and we keep taking in drugs in our bodies either traditional or conventional pharmaceutical products as they are being discovered, developed and distributed.  But for a non medical personnel or for someone with little or no knowledge about such substances, less is known about the possible interaction of such drugs with our bodies not even the possible adverse effects or drug-drug interactions that we may encounter.  It will actually Suprise you to know the for every substance we meet, there is a an increasing potential to get toxicity from it.  

There is also constant fear that our incredibly increasing self administration of medical compounds will once cause a bigger burden of disease exaggeration like it has never been before.  This being via introduction of antimicrobial drug resistance and this is a great topic of concern these days.  If you have not been following my articles, you can click on the link below to read more about drug resistance.  Antimicrobial drug resistance, a topic of concern.  In this article we are going to look at the brief goings of some of the most common medications that we encounter on a daily basis, the reason we take them and the possible predictable outcomes of such substances and if possible, the possible toxicities from them.

FORMULATION OF DRUGS:  Drugs are formulated in different ways basing on the systems they are intended to act upon.  Some are formulated as capsules for swallowing, some as tablets, others like suspensions and for topical agents as ointments.  For each drug formulation, there are intentions as to why it was did that way and not in any way should a patient manipulate a drug without prior advice from a trained medical personnel.  Let's say you are give capsules to swallow, it is not advisable at all to open such capsules.  The reason drugs are formulated differently is something to do with their pharmacokinetics and pharmacodynamics which we discussed earlier and if you would like to read more about them, click on the links below.  Any attempt to modulate the drug from it's original formulation will change either it's absorption, distribution of metabolism by the body.  Pharmacokinetics of drugs  Pharmacodynamics of drugs

It should be noted however that, as long as many drugs may be tablets, there maybe their equivalents in syrups, suspensions and or ointments and it turns out that, you only have to use any drug formulation prior to consultation from a trained medical personnel.

ROUTES OF DRUG ADMINISTRATION:  First, before any drug is taken, there must be a specific route it should undertake.  Some drugs are taken via the mouth and we shall later be relating to that as the oral route, other are taken via the nose and we shall be taking that as inhalational route, while for others the drug is injected into the vein and muscle tissue and we shall be addressing those and intravenous and intramuscular route of drug administration respectively. If you have not been following us, click here to read more about routes of drug administration.

Each of the drug routes used during drug administration has a purpose and not at any point a drug should be administered via a non intended route.

MECHANISM OF ACTION:  For any drug, there must be a way it interacts with the human body and or microbes and cause a desire effect, which we sometimes we refer to as the drug's pharmacodynamics.  It is pharmacodynamics actually that gives a clinician the order of writing a prescription.  The mechanism action also helps in understanding the possible side effects, adverse effects and if any the toxic effects of that particular drug and to get details, let us look at a few examples.

1.  An infection by Salmonella bacteria will require a drug that can kill the bacteria and in that case, and antibiotic will be indicated, with it's mechanism of action being bacteriacidal.

2.  An asthmatic attack will mean we are having impared gaseous exchange and in that case one of the drugs to be indicated, will have a potential to widen the brochi, being a brochodilator by mechanism of action.

EXCRETION OF DRUGS FROM THE BODY:  Once taken in and they have finished exerting their effects or reached peak desire concentrations, drugs must be eliminated from the body.  This happens to either the unchanged drug or metabolites and end products of such drugs.  The chief organs and systems that play this role include the kidney that eliminates most of the drugs via the urine, the gastrointestinal tract that eliminates components through faeces, and for some via the skin and respiratory system.

RELATED;

1.  DYNAMICS OD THE HUMAN BODY-SYSTEM MAKEUP

2.  THE INTRAMASCULAR ROUTE OF DRUG ADMINISTRATION

3.  DYNAMICS OF INFECTIOUS DISEASES

4.  THE HUMAN KIDNEYS

5.  ANTIMICROBIAL DRUG RESISTANCE

WATER INTAKE AND OUTPUT

INTRODUCTION: Most of the water the body requires comes from the ingestion of liquids, and this amount averages 1600 ml per day. The food we eat also contains water. Even foods we think of as somewhat dry, such as bread, contain significant amounts of water. The daily water total from food averages 700 ml. The last source of water, about 200 ml per day, is the metabolic water that is a product of cell respiration. The total intake of water per day, therefore, is about 2500 ml, or 2.5 liters.

DAILY WATER OUTPUT: Most of the water lost from the body is in the form of urine produced by the kidneys; this averages 1500 ml per day. About 500 ml per day is lost in the form of sweat, another 300 ml per day is in the form of water vapor in exhaled air, and another 200 ml per day is lost in feces. The total output of water is thus about 2500 ml per day. Naturally, any increase in water output must be compensated for by an increase in intake. Someone who exercises strenuously, for example, may lose 1 to 2 liters of water in sweat and must replace that water by drinking more fluids. In a healthy individual, water intake equals water output, even though the amounts of each may vary greatly from the averages just mentioned.

REGULATION OF WATER INTAKE AND OUTPUT: The hypothalamus in the brain contains osmoreceptors that detect changes in the osmolarity of body fluids. Osmolarity is the concentration of dissolved materials present in a fluid. Dehydration raises the osmolarity of the blood; that is, there is less water in proportion to the amount of dissolved materials. Another way to express this is to simply say that the blood is now a more concentrated solution. When dehydrated, we feel the sensation of thirst, characterized by dryness of the mouth and throat, as less saliva is produced. Thirst is an uncomfortable sensation, and we drink fluids to relieve it. The water we drink is readily absorbed by the mucosa of the stomach and small intestine and has the effect of decreasing the osmolarity of the blood. In other words, we can say that the water we just drank is causing the blood to become a more dilute solution, and, as the serum osmolarity returns to normal, the sensation of thirst diminishes.

WATER BALANCE AND THE ROLE OF ANTIDIURETIC HORMONE: As you may recall, the hypothalamus is also involved in water balance because of its production of antidiuretic hormone (ADH), which is stored in the posterior pituitary gland. In a state of dehydration, the hypothalamus stimulates the release of ADH from the posterior pituitary. Antidiuretic hormone then increases the reabsorption of water by the kidney tubules. Water is returned to the blood to preserve blood volume, and urinary output decreases.

WATER BALANCE AND THE ROLE OF ALDOSTERONE: The hormone aldosterone, from the adrenal cortex, also helps regulate water output. Aldosterone increases the reabsorption of Na ions by the kidney tubules, and water from the renal filtrate follows the Na ions back to the blood. Aldosterone is secreted when the Na ion concentration of the blood decreases or whenever there is a significant decrease in blood pressure (the renin-angiotensin mechanism). Several other factors may also contribute to water loss. These include excessive sweating, hemorrhage, diarrhea or vomiting, severe burns, and fever. In these circumstances, the kidneys will conserve water, but water must also be replaced by increased consumption. Following hemorrhage or during certain disease states, fluids may also be replaced by intravenous administration. A less common occurrence is that of too much water in the body. This may happen following overconsumption of fluids. The osmolarity of the blood decreases, and there is too much water in proportion to electrolytes (or, the blood is too dilute). This condition may become symptomatic, and is called water intoxication. Symptoms are dizziness, abdominal cramps, nausea, and lethargy. Convulsions are possible in severe cases, and fluids must be restricted until the kidneys can excrete the excess water. A hormone that will contribute to that is atrial natriuretic peptide (ANP), which is secreted by the atria when blood volume or blood pressure increases. ANP then decreases the reabsorption of Na ions by the kidneys, which increases urinary output of sodium and water. Also, secretion of ADH will diminish, which will contribute to a greater urinary output that will return the blood osmolarity to normal.

RELATED;

1.  Body fluids

2.  Water, the universal solvent

REFERENCES

THERAPEUTIC INDEX AND THERAPEUTIC WINDOW

 

INTRODUCTION:  Administering a dose of the drug that produces an optimum therapeutic response for each individual patient is only one component of effective pharmacotherapy. Medical practitioners must also be able to predict whether the dose is safe for the patient and this is one other thing that is fully tested during clinical trials.  Frequency distribution curves can also be used to represent the safety of a drug. For example, the median lethal dose (LD₅₀) is often determined in preclinical trials, as part of the drug development process. The LD₅₀ is the dose of drug that will be lethal in 50% of the investigation group of animals. As with ED₅₀, a group of animals will exhibit considerable variability in lethal dose; what may be a nontoxic dose for one animal may be lethal for another.

DETERMINATION OF THERAPEUTIC INDEX:  To examine the safety of a particular drug, the LD₅₀ can be compared with the ED_50. For example, 10 mg of drug X is the average effective dose, and 40 mg is the average lethal dose. The ED₅₀ and LD₅₀ can then be used to calculate an important value in pharmacology, a drug’s therapeutic index, which is the ratio of a drug’s LD₅₀ to its ED₅₀.  

THERAPEUTIC WINDOWS:  Now that we have looked at therapeutic index as a ration, therapeutic window on the other side, is a range between the drug that can cause a desired effect in 50% also known as Effective dose 50 (ED50) of the investigational animals to the drug dose that can cause toxicity in 50% of the investigational animals also known as Toxic dose 50 (TD50).

INTERPRETATION OF THERAPEUTIC INDEX:  The larger the difference between the two doses, the greater the therapeutic index. In the example above, the therapeutic index is 4 (40 mg ÷ 10 mg). Essentially, this means that it would take an error in magnitude of approximately 4 times the average dose to be lethal to a patient. Thus, the therapeutic index is a measure of a drug’s safety margin.  The higher the value, the safer the medication.

MEDICAL IMPLICATIONS OF THERAPEUTIC INDEX:  The therapeutic index offers the medical personnel practical information on the safety of a drug and a means to compare one drug with another. Because the LD₅₀ cannot be experimentally determined in humans, the median toxicity dose (TD₅₀) is a more practical value in a clinical setting. The TD₅₀ is the dose that will produce a given toxicity in 50% of a group of patients. The TD50 value may be extrapolated from animal data or based on adverse effects recorded in patient clinical trials.

 

RELATED;

1. PHASES OF CLINICAL TRIALS

2. DRUG DISCOVERY AND DEVELOPMENT

3. RANDOMISATION

4.  PHARMACOLOGY AND THERAPEUTICS

REFERENCES

HEART RATE

 

INTRODUCTION: A healthy adult has a resting heart rate also known as, pulse, of 60 to 80 beats per minute, which is the rate of depolarization of the Sinoartrial node abbreviated as SA node. The SA node actually has a slightly faster rate, closer to 100 beats per minute, but is slowed by parasympathetic nerve impulses to what we consider a normal resting rate. A rate less than 60, except for athletes, is called bradycardia; a prolonged or consistent rate greater than 100 beats per minute is called tachycardia.

FETAL AND INFANTS’ HEART RATE: A child’s normal heart rate may be as high as 100 beats per minute, that of an infant as high as 120, and that of a near-term fetus as high as 140 beats per minute. These higher rates are not related to age, but rather to size: the smaller the individual, the higher the metabolic rate and the faster the heart rate.

RELATED;

1. THE HEART AND CARDIAC FUNCTIONING

2. HEART SOUNDS AND CIRCULATION THROUGH THE HEART

3. BLOOD PRESSURE AND HYPERTENSION

REFERENCES

CONCURRENT USE OF OVER THE COUNTER (OTC) DRUGS

CONCURRENT USE OF OVER THE COUNTER (OTC) DRUGS:  In drug use, we have two broad categories namely; Over the counter drugs (OTC) and Prescription only Medications (POM).  The first category looks at drugs and medications that clients can easily buy from drug shops and any type of retail shop without official consultation from a trained and authorized medical personnel.  The last one, describes those drugs that can only be given and only allowed to be given following a medical prescription and directions from a trained medical personnel.  The medical prescription.  Whether a pharmaceutical product bought from a recognised pharmacy, a traditional medication from traditional healers and drug shops selling traditional and complimentary medications or drugs of abuse such as alcohol and caffeinated drinks, the brief pharmacological intervention of all chemicals bought relieve some sort of disorder qualifies to be OTC.  In our discussion here, we are going to look at the OTC drugs and their types, and then the consequences of their use in humans.

COMMON OTC DRUGS:  Some of the most common drugs used as the "Over the Counter medications" include but not limited to analgesics or literally known as pain killers.  These drugs are bought and used by clients after having extraneous activities, following toothache and for others, after sensation of fever. Here we have some common drugs including but not limited to; Paracetamol (Panadol), Indomethacin (Indocid), Diclofenac and Ibuprufen among others.  We also commonly have clients buy antibiotics of different types and among some of the most common include but not limited to; Metronidazole, Amoxicillin, Artemisinin combination Therapies and others.  There is also misuse of peptic ulcer medications such as Omeprazole and antiacids containing magnesium and aluminum and antihistamine.

Such drugs have ever been prescribed to the patient and or, they have been used by the patient for a long period of time.  The so called pain killers are used by many people in our communities day to day.  These are the likes of Indomethacin, Dicrofenac, Paracetamol or Acetaminophene among others.  But the use of these drugs comes at a cost, that they are not the safest chemical to use frequently.

Despite the fact that they may not be the perfect medications to be used for whatever condition the patient may be using them for, there is no thorough evaluation of the patients' condition before their use, and they are normally used in either under or overdose for Un predetermined time.

CONSEQUENCES OF USING OTC:  Some of the most common consequences of using on the counter drugs comes as a result of ether underdose and or overdose, irrational prescription, or drug resistance.  Let us look at each drug manufactured and marketed to have a predetermined dosage regimen where, you are required to take some amount of the drug in  a given time t.  Sometimes you notice that depending on the patient's status, the dosage can be adjusted at various degrees making let's say a drug being available in 20mg, 40mg and 45 mg per Kg body weight.  It will not be easy for a non medical personnel buying such a drug to notice the different strength, subjecting them to less or more than the actual dose they need.  I have discussed a lot about therapeutic window and therapeutic index in the past as you can read about the details from here.

When it comes to irrational prescription, there is a tendency of patients to buy drugs that because their presenting signs and symptom are similar to those that a friend had, and they saw the drug they were given.  When it comes to Drug resistance, this is one of the major topics of concern when it come to antimicrobial drug use especially the so called antibiotics.  Without a proper laboratory investigation and consultation from a trained medical personnel, there would be no need to take any antibiotic for any anticipated medical condition.

RELATED;

1.  DYNAMICS OF DRUGS AND THE HUMAN BODY

2.  DRUG USE AND CLINICAL TRIALS

3.  DRUG USE IN RELATION TO PREGNANCY

4.  CLASSIFICATION OF DRUGS

5.  ANALGESICS

6.  ANTIBIOTICS

PRETERM LABOR AND BIRTH

INTRODUCTION: Preterm labor is defined as the presence of regular uterine contractions that occur before 37 completed weeks of gestation and are associated with cervical changes. It is often difficult to diagnose preterm labor because of the absence of definitive measurements. Preterm birth is delivery that occurs prior to the completion of 37 completed weeks or an equivalent of 259 days of gestation. Because it is the most common cause of perinatal morbidity and mortality in many countries, prevention and treatment of preterm birth is one of the major focus of obstetric care.

COMPLICATIONS OF PRETERM BIRTH: In addition to perinatal death in the very young fetus, common complications of preterm birth include respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, sepsis, neurologic impairment, and seizures. Long-term morbidity associated with preterm delivery includes bronchopulmonary dysplasia and developmental abnormalities, including cerebral palsy.

CLASSIFICATION: Preterm births may be classified into two general presentations: Spontaneous and indicated. Approximately 50% of preterm births result from spontaneous preterm labor with intact membranes; around 40% result from preterm premature rupture of membranes. The remaining more than 10% occur following deliberate intervention for a variety of maternal or obstetric complications such as, eclampsia.

CAUSE OF PRETERM LABOR: Preterm labor may represent a final common pathway for a number of pathogenic processes. The four main processes include;

(1) activation of the maternal or fetal hypothalamic–pituitary–adrenal axis due to maternal or fetal stress,

(2) decidual–chorioamniotic or systemic inflammation caused by infection,

(3) decidual hemorrhage, and

(4) pathologic uterine distention.

FACTORS ASSOCIATED WITH PRETERM LABOR

1. Prior history of preterm birth

2. Preterm uterine contractions

3. Premature rupture of membranes

4. Behavorial risk factors: Low maternal pregnancy, weight, Smoking, Substance abuse, Short interpregnancy interval

5. Current pregnancy factors: Short cervical length, Multifetal gestation, Vaginal bleeding, Urinary tract infections, Genital tract infection and Periodontal disease

RELATED;

1.  PREGNANCY AND CHILDBIRTH

2.  PARTURITION AND LABOR

3.  DRUGS USED IN LABOR

REFERENCES

DRUG SPECTRUM OF ACTIVITY

TEST QUESTIOS

1.  How do I know a drug can kill more than one microbe?

DRUG SPECTRUM OF ACTIVITY:  Today we have thousands of different types of drugs i different formulations treating different diseases.  But the question would be; Which drug is best in treating disease X?  And the immediate answer will be, there are several drugs that all can cure the same disease, X.  And then the next question will be; How do I choose from drug A, B, C, and D the best and affordable drug for myself and or the patient?  Then the answer will be; Before you think about affordability, look at the spectrum of activity for each specific drug and then choose accordingly.  In our discussion here, we are going to look at how specific drugs will be able to treat specific infections with maximum efficiency but before we continue, if you have not been following us, you may also be interested in reading about; Dynamics of drugs and the human body and Classification of drugs

When it comes to drug actions especially antimicrobial agents or dugs that kill microbes, there is a range of organisms onto which the drug will be effective.  Some drugs are capable of killing a wide range of microbes while others can just kill a few or even one strain of microbes.  In our discussion here, we are going to look at the range of microbes that can be killed by specific drugs but before we continue, if you have not been following us, you may want to read about classification of drugs that we discussed recently from the link below;  Classification od drugs

BROAD SPECTRUM ANTIBIOTICS:  As we continue looking at antimicrobial agents, we have drugs that can target several microbes and therefore such drugs can be given in multiples infections with various microbes.  These are collectively known as broad spectrum antibiotics.  If these are antibacterial let's say, they will be able to handle both gram positives and gram negative bacteria or even having a potential to tackle on acid fast bacilli too.  And we we have several classes of drugs here as we are going to be briefly mentioning a couple of them.

Previously we have been looking at the different types antibiotics basing on their mechanism of action and in some of our previous discussions we looked at classification of drugs basing on the microbes they act upon.  Some of the examples of broad spectrum antibiotics we can have here are specific to bacteria and they include but not limited to; 1) Metronidazole, a nitroimidazole that can be used to treat both bacteria and protozoa.

NARROW SPECTRUM ANTIBIOTICS:  So much we have seen when it comes to broad spectrum antibiotics, now let us look drugs with a narrow spectrum of activity.  These are drugs that are limited in action and they will be able to kill just a selected number of microbes.  In this set of drugs, we look at drugs like Isoniazid, which is almost entirely active on only mycobacteria.

RELATED;

1.  CLASSIFICATION OF DRUGS

2.  DYNAMICS OF DRUGS AND THE HUMAN BODY

3.  METRONIDAZOLE

4.  ISONIAZID

HYPERTENSION

 

OBJECTIVES OF THE SESSION:  By the end of our discussion here, the learner/reader/medical student will be able to;

1.  Differentiate between the normal and hypertensive blood pressures

2.  Explain the effects of increasing blood pressure on the body organs

3.  Describe the different types and stages of hypertension

INTRODUCTION: Hypertension is defined as a systolic blood pressure greater than 140 mmHg and a diastolic pressure greater than 90 mmHg, based on two or more measurements. Hypertension can be classified as follows:

a) Normal: systolic less than 120 mmHg; diastolic less than 80 mmHg

b) Prehypertension: systolic 120 to 139 mmHg; diastolic 80 to 89 mmHg

c) Stage 1: systolic 140 to 159 mm Hg; diastolic 90 to 99 mmHg

d) Stage 2: systolic 160 mmHg; diastolic 100 mmHg

CONSEQUENCES OF HYPERTENSION: Hypertension is a major risk factor for atherosclerotic cardiovascular disease, HF, stroke, and kidney failure. Hypertension carries the risk for premature morbidity or mortality, which increases as systolic and diastolic pressures rise. Prolonged blood pressure elevation damages blood vessels in target organs (heart, kidneys, brain, and eyes).

Essential (Primary) Hypertension: In the adult population with hypertension, between 90% and 95% have essential (primary) hypertension, which has no identifiable medical cause; it appears to be a multifactorial, polygenic condition. For high blood pressure to occur, an increase in peripheral resistance and/or cardiac output must occur secondary to increased sympathetic stimulation, sodium reabsorption, increased renin–angiotensin–aldosterone system activity, decreased vasodilation of the arterioles, or resistance to insulin action. Hypertensive emergencies and urgencies may occur in patients whose hypertension has been poorly controlled, whose hypertension has been undiagnosed, or in those who have abruptly discontinued their medications.

Secondary Hypertension: Secondary hypertension is characterized by elevations in blood pressure with a specific cause, such as narrowing of the renal arteries, renal parenchymal disease, hyperaldosteronism (mineralocorticoid hypertension), certain medications, pregnancy, and coarctation of the aorta. Hypertension can also be acute, a sign of an underlying condition that causes a change in peripheral resistance or cardiac output.

CLINICAL MANIFESTATIONS: Physical examination may reveal no abnormality other than high blood pressure. Changes in the retinas with hemorrhages, exudates, narrowed arterioles, and cotton–wool spots (small infarctions), and papilledema may be seen in severe hypertension. Symptoms usually indicate vascular damage related to organ systems served by involved vessels. Coronary artery disease with angina or myocardial infarction is the most common consequence. Left ventricular hypertrophy may occur; HF ensues. Pathologic changes may occur in the kidney (nocturia and increased BUN and creatinine levels). Cerebrovascular involvement may occur (stroke or transient ischemic attack [TIA] [ie, alterations in vision or speech, dizziness, weakness, a sudden fall, or transient or permanent hemiplegia]).

ASSESSMENT AND DIAGNOSTIC METHODS: History and physical examination, including retinal examination; laboratory studies for organ damage, including urinalysis, blood chemistry (sodium, potassium, creatinine, fasting glucose, total and high-density lipoprotein); ECG; and echocardiography to assess left ventricular hypertrophy. Additional studies, such as creatinine clearance, renin level, urine tests, and 24-hour urine protein, may be performed.

MEDICAL MANAGEMENT: The goal of any treatment program is to prevent death and complications by achieving and maintaining an arterial blood pressure at or below 140/90 mm Hg (130/80 mm Hg for people with diabetes mellitus or chronic kidney disease), whenever possible. Nonpharmacologic approaches include weight reduction; restriction of alcohol and sodium; regular exercise and relaxation. A DASH (Dietary Approaches to Stop Hypertension) diet high in fruits, vegetables, and low-fat dairy products has been shown to lower elevated pressures. Select a drug class that has the greatest effectiveness, fewest side effects, and best chance of acceptance by patient. Two classes of drugs are available as first-line therapy: diuretics and beta-blockers. Promote compliance by avoiding complicated drug schedules.

RELATED;

1. CONGESTIVE CARDIAC FAILURE  

2. CHAMBERS AND CIRCULATION THROUGH THE HEART  

3. CARDIAC CYCLE AND THE HEART SOUNDS  

4. ARTERIOSCLEROSIS

5.  MEDICAL CONDITIONS

REFERENCES

DIABETES MELLITUS

 

INTRODUCTION: Diabetes mellitus is a group of metabolic disorders characterized by elevated levels of blood glucose (hyperglycemia) resulting from defects in insulin secretion, insulin action, or both. INSULIN AS A CHEMICAL OF LIFE  Three major acute complications of diabetes related to short-term imbalances in blood glucose levels are hypoglycemia, diabetic ketoacidosis (DKA), and hyperglycemic hyperosmolar nonketotic syndrome (HHNS). Long-term hyperglycemia may contribute to chronic microvascular complications such as kidney and eye disease, and neuropathic complications. Diabetes is also associated with an increased occurrence of macrovascular diseases, including coronary artery disease (myocardial infarction), cerebrovascular disease (stroke), and peripheral vascular disease. [coronaryartery disease]

TYPES OF DIABETES TYPE 1 (FORMERLY INSULIN-DEPENDENT DIABETES MELLITUS): About 5% to 10% of patients with diabetes have type 1 diabetes. It is characterized by destruction of the pancreatic beta-cells due to genetic, immunologic, and possibly environmental factors. In this medical condition, insulin injections are needed to control the blood glucose levels. Type 1 diabetes has a sudden onset, usually before the age of 30 years.

TYPE 2 (FORMERLY NON–INSULIN-DEPENDENT DIABETES MELLITUS): About 90% to 95% of patients with diabetes have type 2 diabetes. It results from a decreased sensitivity to insulin also known as insulin resistance, or from a decreased amount of insulin production. Type 2 diabetes is first treated with diet and exercise, and then with oral hypoglycemic agents as needed. Type 2 diabetes occurs most frequently in patients older than 30 years and in patients with obesity.

Gestational Diabetes Mellitus: Gestational diabetes is characterized by any degree of glucose intolerance with onset during pregnancy (second or third trimester). Risks for gestational diabetes include marked obesity, a personal history of gestational diabetes, glycosuria, or a strong family history of diabetes. High-risk ethnic groups include Hispanic Americans, Native Americans, Asian Americans, African Americans, and Pacific Islanders. It increases their risk for hypertensive disorders of pregnancy. 

Clinical Manifestations: Polyuria, polydipsia, and polyphagia. Fatigue and weakness, sudden vision changes, tingling or numbness in hands or feet, dry skin, skin lesions or wounds that are slow to heal, and recurrent infections. Onset of type 1 diabetes may be associated with sudden weight loss or nausea, vomiting, or stomach pains. Type 2 diabetes results from a slow (over years), progressive glucose intolerance and results in long-term complications if diabetes goes undetected for many years such as in case of eye disease, peripheral neuropathy, or peripheral vascular disease. Complications may have developed before the actual diagnosis is made.

Signs and symptoms of DKA: These include; abdominal pain, nausea, vomiting, hyperventilation, and a fruity breath odor. Untreated DKA may result in altered level of consciousness, coma, and death.

RELATED;

1.  DRUG ADMINISTRATION TECHNIQUES USED IN MEDICINE  

2.  DIABETES INSPIDUS

3.  INSULIN AND THE HUMAN BODY

4.  MEDICINE AND SURGERY 

REFERENCES