Fluid therapy rehydration

The fluid therapy plan should be divided into three stages initial resuscitation, rehydration and maintenance. The focus of resuscitation is the rapid reversal of hypovolemia. Rehydration aims to replace fluid losses. The maintenance phase aims to prevent the occurrence of further fluid deficits. In severely hypovolemic horses, a transition phase, in which fluid rates are higher than those calculated for the rehydration phase, may be necessary after initial resuscitation. The need for this should be assessed based on the clinical and laboratory responses to the initial resuscitation. Although plasma electrolyte imbalances may... 

The rehydration phase aims to replace extravascular fluid losses. Crystalloid fluids are a logical choice for rehydration as they readily diffuse into the interstitial fluid from the vasculature (Spalding Goodwin 1999, Vaupshas Levy 1990). Rehydration should take place over the first 12-24 h of therapy. The amount given should be based on the clinical estimate of the degree of dehydration and the response to fluid therapy. 

Acute bronchitis is caused most commonly by respiratory viruses and almost always is self-limiting with therapy targeting associated symptoms, such as lethargy, malaise, or fever (ibuprofen or acetaminophen), fluids for rehydration, and in some patients cough suppressants. The routine use of antibiotics should be avoided. 

Because the severity of symptoms and the absolute serum concentration are poorly correlated in some patients, institution of therapy should be dictated by the clinical scenario. All patients with hypercalcemia should be treated with aggressive rehydration normal saline at 200 to 300 mL/hour is a routine initial fluid prescription. For patients with mild hypocalcemia, hydration alone may provide adequate therapy. The moderate and severe forms of hypercalcemia are more likely to have significant manifestations and require prompt initiation of additional therapy. These patients may present with anorexia, confusion, and/or cardiac manifestations (bradycardia and arrhythmias with ECG changes). Total calcium concentrations greater than 13 mg/dL (3.25 mmol/L) are particularly worrisome, as these levels can unexpectedly precipitate acute renal failure, ventricular arrhythmias, and sudden death. 

Multiple pharmacologic interventions are available for the treatment of hypercalcemia (Table 96-10). Furosemide 20 to 40 mg/day may be added to hydration once rehydration has been achieved to avoid fluid overload and enhance renal excretion of calcium. Although effective in relieving symptoms, hydration and diuretics are temporary measures that are useful until the onset of antiresorptive therapy thus hydration and antiresorptive therapy should be initiated simultaneously. 

The mainstay of treatment for cholera consists of fluid and electrolyte replacement with ORT to restore fluid and electrolyte losses. Rice-based rehydration formulations are the preferred ORT for cholera patients. In patients who cannot tolerate ORT, IV therapy with Ringer s lactate can be used. 

Supportive therapy Maintenance of blood pressure, artificial respiration, rehydration (fluid/electrolyte therapy) and control of convulsions. 

Diarrhoea is often of infective origin, but management is generaiiy non-specific. Diarrhoea is aiso common foiiowing antibiotic therapy which disturbs normai bowei flora. Repiacement therapy using eiectroiyte soiutions may be needed, and can be iife-saving in severe diarrhoea, especiaiiy in chiidren. Orai rehydration is preferred, aithough parenterai fluids may be required. 

CM was started on intravenous insulin, fluids, and electrolyte replenishment. Her nausea and vomiting resolved and, although initially, she required 60-70 units of insulin intravenously per day to attain glycaemic control, her blood glucose dropped to 7.4 mmol/L after 4 days of intensive care. However, despite treatment of her diabetic ketoacidosis, including significant rehydration therapy, CM was still found to have an elevated but stable serum creatinine of 246 micromol/L, and so she was transferred from the intensive care unit to the renal unit for further management. 

Therapies include oral rehydration, absorbents, antimotility agents such as opioids or intestinal flora modifiers. In all cases maintaining fluid intake helps to improve symptoms. Very occasionally, an antibiotic maybe necessary, depending on the organism involved. 

The first line of treatment for acute diarrhoea is fluid and electrolyte replacement by oral rehydration therapy (ORT). 

Rehydration and maintenance of water and electrolytes are primary treatment goals until the diarrheal episode ends. If the patient is volume depleted, rehydration should be directed at replacing water and electrolytes to normal body composition. Then water and electrolyte composition are maintained by replacing losses. Many patients will not develop volume depletion and therefore will only require maintenance fluid and electrolyte therapy. Parenteral and enteral routes may be used for supplying water and electrolytes. If vomiting and dehydration are not severe, enteral feeding is the less costly and preferred method. In the United States, many commercial oral rehydration preparations are available (Table 36-3). 

For those patients with normal to moderately impaired renal function, the cornerstone of initial treatment of hypercalcemia is volume expansion to increase urinary calcium excretion (see Table 49-6). Patients with severe renal insufficiency usually do not tolerate volume expansion they may be initiated on therapy with calcitonin. Patients with symptomatic hypercalcemia are often dehydrated secondary to vomiting and polyuria thus rehydration with saline-containing fluids is necessary to interrupt the stimulus for sodium and calcium reabsorption in the renal mbule. ° Rehydration can be accomplished by the infusion of normal saline at rates of 200 to 300 mL/h, depending on concomitant conditions (primarily cardiovascular and renal) and extent of hypercalcemia. Adequacy of hydration is assessed by measuring fluid intake and output or by central venous pressure monitoring. Loop diuretics such as furosemide (40 to 80 mg IV every 1 to 4 hours) or ethacrynic acid (for patients with sulfa allergies) may also be instiffited to increase urinary calcium excretion and to minimize the development of volume overload from the administration of saline (see Table 49-6). Loop diuretics such as furosemide... 

Fluid and electrolyte replacement is the cornerstone of therapy. Oral rehydration therapy is preferred in most cases of mild and moderate diarrhea. The necessary components of oral replacement therapy are glucose, sodium, potassium, chloride, and water. 

After startiug rehydration therapy, parents should be instructed to observe the child for a reversal of the signs of dehydration, increased stool consistency, and decreased stool frequency. If ORT is not improving the fluid status and the patient continues to produce frequent, large-volume watery stools, close supervision with medical support is justifled. ... 

Appropriate follow-up care of patients with acute diarrhea is based on successful restoration of fluid losses. The clinical signs and symptoms (see Table 111-1) that led to the diagnosis also can indicate adequate rehydration and should be assessed frequently. Because oral rehydration therapy is now preferred, routine laboratory testing often is unnecessary. Electrolytes should be measured in those receiving parenteral fluids, when oral replacement fails, or when signs of hypernatremia or hypokalemia are present. Follow-up stool samples to ensure complete evacuation of the infecting pathogen may be necessary only... 

Regardless of the serotypes, the primary goal of therapy is restoration of fluid and electrolyte losses caused by watery diarrhea. ORT is the preferred method of rehydration, and several studies showed reduction in fluid requirements by 32% to 35% when rice-based instead of glucose-based ORT solutions are used (50-80 g rice instead of 20 g glucose per liter). In patients who cannot tolerate ORT, IV Ringer s lactate solution can be used. Normal saline is not recommended because it does not correct metabolic acidosis. After rehydration, maintenance fluid is given based on accurate recording of intake and output volumes. 

The need for fluid replacement is obvious. Oral rehydration is preferred over intravenous administration of fluids and electrolytes since it is noninvasive. In many third world countries, it is the only therapy available in remote areas. The rehydration formula includes 50-80 g/L rice (or other starch), 3.5 g/L sodium chloride, 2.5 g/L sodium bicarbonate, and 1.5 g/L potassium chloride. Oral rehydration takes advantage of the cotransport of Na and glucose across the cells lining the intestine. Thus, the channel protein brings glucose into the cells, and Na+ is carried along. Movement of these materials into the cells will help alleviate the osmotic imbalance, reduce the diarrhea, and correct the fluid and electrolyte imbalance. 

Clinical Perspective Oral Rehydration Therapy, above, describes one of the most lethal and pervasive examples of cellular fluid imbalance. 

Dennis Veere. Dennis Veere was diagnosed with cholera. He was ) placed on intravenous rehydration therapy, followed by oral rehydration therapy with high glucose and Na -containing fluids (to be continued in Chapter 11). 

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