CHAPTER ONE
- INTRODUCTION
Preeclampsia is a pregnancy specific syndrome and is one of the leading cause of maternal and fetal morbidity and mortality. Preeclampsia is defined as the existence of hypertension, proteinuria and edema, occurring after 20 weeks of gestation in previously normotensive women, (Sunithaet al.,2012)
The aetiology of preeclampsia is yet unknown, however, it is associated with alteration in electrolyte status in pregnant women (electrolytes like sodium, potassium, chloride, bicarbonate etc). Hypertension is a universal problem and it complicates at least 10% of all pregnancies. Fluid and electrolyte abnormalities are common in critically ill patients of which preeclampsia patients are not excluded,(Indumati et al.,2011). Hypertension or high blood pressure occurs when the blood flowing through the artery walls move faster and harder than needed. This excess pressure unnecessarily pounds the blood vessels and can cause them to get weak. However, when too much sodium is ingested, it can cause the body to retain more water and fluid than is necessary. This hoarding of excess fluid or water by the body and its continuous movement through the body causes blood pressure to increase inside the blood vessel walls,(Carretero and Oparil, 2015).
Electrolyte imbalances have been in the spotlight of medical focus for quite sometime and this has to do with the fact that electrolytes play paramount roles in acid base balance, muscle function as well as serving as co-factors for enzymes. Abnormal electrolyte concentrations may be the cause of, or consequence of a variety of medical disorders, (Burtis and Burns, 2015).
Electrolytes are charged low-molecular-mass molecules that are present in plasma and cytosol; usually ions of sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate, sulfate and lactate,(Brutis and Bruns,2015).Electrolytes may be classified as anions, which are negatively charged ions that migrate towards the anode or as cations, which are positively charged ions that migrate towards the cathode, with the anode being the positive electrode and the cathode being the negative electrode, all in an electrochemical environment,(Indumati et al., 2011)
Among the physiologically important electrolytes, we shall focus on the four major electrolytes for the purpose of this study which include: Na+ ,K+, Cl–and HCO3– which occur primarily as free ions in contrast to Mg2+, Ca2+, trace elements which are bound by proteins, especially albumin,(Burtis and Burns, 2015). Our focus on the four major electrolytes (Na+ ,K+, Cl–and HCO3–) the purpose of this study, stems from the fact that the determination of body fluid concentration of these four major electrolytes is readily carried out in the medical laboratories as ‘electrolyte profile’ and are of high clinical significance,(Baha,2014).
The specimens which are typically assayed in the laboratory for their electrolyte content are mostly serum and plasma. Capillary blood is another sample commonly analysed. Heparinised whole blood arterial or venous specimens obtained for blood gases and pH determinations may also be used with direct ion-selective electrodes (ISES). The use of plasma or whole blood provides the advantage of shortening turnaround time because it is not necessary to wait for the blood to clot, (Manjareeka and Nanda,2012).
Furthermore, plasma or whole blood provides a distinct advantage in determining K+ concentrations which are invariably higher in serum depending on platelet count (Burtis and Burns, 2015).
Sodium is the major cation present in the extracellular fluid. About 40% of the body’s serum is contained in the bones. Approximately 2-5% occurs within body organs and cells and the remaining 55% is in blood plasma and other extracellular fluids. The amount of sodium in blood plasma is typically 140nM, a much higher amount than as found in intracellular sodium (about 5nM). This asymmetric distribution of sodium ions is essential for human life, (Banks,2010).
Sodium helps in the regulation of acid base balance as it readily combines with chloride (Cl–) or bicarbonate (HCO3–) to regulate the acid base balance. Sodium is also largely responsible for the osmolarity of vascular fluids. Doubling Na+ levels gives the approximate serum osmolarity. It is also involved in the regulation of body fluid, such that increased serum levels can cause water retention,(Banks,2010).It maintains blood pressure in the sense that while sodium shifts into the cells, potassium (another electrolyte) shifts out of the cells repeatedly to maintain water balance and neuromuscular activity,(Anuradha and Begum,2016)
Sodium occurs naturally in most foods. For example milk, beef and cereals have sodium. It is also present in drinking water. Sodium is also added to various food products. Some of these added forms are monosodium glutamate, sodium nitrate, sodium saccharine, baking soda (sodium bicarbonate), sodium benzoate. The main source of sodium is the sodium chloride used in cooking and seasoning. About 4g of sodium is ingested everyday and about 96% of the sodium is excreted in the urine (Nwanjo, 2011).
Potassium is the most abundant intracellular cation. Only about 20% of the body potassium is extracellular. Since most intracellular potassium is contained within muscle cells, total body potassium is roughly proportional to lean body mass. An average 70kg adult has about 3500mEq of potassium. Potassium is one of the body’s most important minerals and most especially it is relevant to this research as it aids the lowering of blood pressure. Potassium as an electrolyte regulates the water balance and acid base balance in the blood and tissues alongside sodium,(Sayyed and Sonttake,2013).
Potassium is also important in cellular biochemical reactions and energy metabolism. It is active in glycogen and glucose metabolism, converting glucose to glycogen and that can be stored in the liver for future energy. It is also vital for the normal growth and building of muscles. It is a vital constituent of extracellular fluid since it influences muscle activity, especially the cardiac muscles,(Olanike,2014).The normal dietary intake of potassium is 4g/day. It is found in a variety of food sources as well as many fruits and vegetables. Most fruits and vegetables are high in potassium and low in sodium which enables them to prevent hypertension. Most potassium in food’s are lost during processing and canning of foods while less is lost from frozen fruits and vegetables (Nwanjo, 2011)
Potassium enters the cells more readily than sodium and instigates the brief sodium-potassium exchange across the cell membrane potential and allows the nerve impulse to progress. This electrical potential gradient created by the ‘sodium-potassium’ pump helps generate muscle contractions and regulate the heart beat which in turn aids or contributes to the regulation of blood pressure (Weeks and Mary, 2011).
Chloride is chiefly an extracellular anion and is present in large quantities in the serum, where it exerts an important influence on acid-base balance and osmotic pressure regulation and water balance, which in turn affects blood pressure (Nwanjo, 2011).
Bicarbonate is the most important buffering system that operates in cells and fluids. It operates mainly in the plasma. It is important in regulating acid base balance in the body (Nwanjo, 2011).
C-reactiveprotein (CRP) is a substance found in the area of acutely Ill individuals that is able to bind to the cellwall C-polyssacharide of Streptococcus pneumoniae. It is an early positive APR (acute phase reaction) and exhibits some of the most dramatic increases in concentration. It has been used extensively as a marker of inflammation, (Burtis and Burns,2015).
Preeclampsia is specific to human pregnancies and is quite transient in the sense that it has the possibility of degenerating to eclampsia in which the pregnant woman actually begins to experience fits of convulsions which gravely compromise the survival of both mother and child. It is for this reason that great care should be taken with preeclamptic women which involves evaluation of electrolyte levels as well as C-reactive protein, which is actually the reason behind this research work, (Bhaskar et al.,2015)
1.1. RESEARCH PROBLEM AND JUSTIFICATION
The research carried out was to investigate pregnant women with increase in blood Pressure as a result of electrolyte imbalance and increased circulating c-reactive protein, compromising the health and life of both mother and fetus. It is for this reason that the electrolyte and C-reactive protein evaluation becomes imperative in preeclamptic women to help advance maternal and foetal care during pregnancy and by implication reduce maternal and foetal morbidity and mortality, especially with this health implication (preeclampsia) of unknown aetiology.
1.2. AIM
The aim of his research work is to evaluate the electrolytes (sodium Na+, potassium K, chloride Cl, and bicarbonate HCO–3) as well as C-reactive protein in preeclampsia patients.
1.3. OBJECTIVES
The main objectives are:
- To determine the level of serum electrolytes in preeclampsia patients.
- To determine the level of serum C-reactive protein in preeclampsia patients.
- To elucidate the correlationship between electrolyte imbalance and preeclampsia.
