Fluid therapy response

From the above, derives the fundamental concept that the newborn infant must be maintained in an adequate degree of hydration and in electrolyte balance in order for the infant to thrive. In some cases, where for one reason or other, the infant is not able to take fluids by mouth in the normal manner, one may need to resort to supplementary fluid therapy by vein. For a rational approach to this problem one needs to have available from the clinical chemical laboratory> rapid response in order to continuously monitor changes in electrolyte levels so that fluids can be modified so as to correct these abnormal-ities. 

Has the goal arterial blood pressure been achieved If not, give additional fluid therapy hourly blending crystalloids and isooncotic colloids based on inadequate blood pressure response. 

The laboratory tests used most commonly to assess hypovolemia are packed cell volume (PCV) and plasma total solids. Unfortunately, these tests are neither sensitive nor specific (Hansen DeFrancesco 2002). The PCV may be increased substantially by splenic contraction, making small increases very hard to interpret. A PCV of >50% usually represents hypovolemia. The plasma total solids (protein measured by refractometer) or total protein concentration (measured by a chemistry analyzer) also increases with hypovolemia. How-ever significant protein loss can occur in disease (particularly colitis), resulting in a low or normal protein concentration despite hypovolemia. Further, hypergammaglobulinemia (e.g. in cyathostomiosis) can increase the plasma total protein concentration without the presence of hypovolemia. The PCV and plasma total solids are most useful when greatly increased or when used serially to monitor the response to fluid therapy. 

Urine specific gravity is useful for monitoring the response to fluid therapy. Urine specific gravity can be measured easily in the field using a... 

The change in CVP in response to a fluid challenge (bolus of fluid) (Webb 1997) is perhaps more accurate but this awaits formal evaluation in the horse. The fluid challenge method of monitoring fluid therapy may prove particularly useful in acute renal failiue or pulmonary edema. In horses without pulmonary edema, a fluid... 

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. 

A. Hypotension, usually responsive to fluid therapy, has been reported with acute overdose. Bradycardia may also occur. 

RISK FOR INEFFECTIVE TISSUE PERFUSION RENAL When the patient is taking a drag tiiat is potentially toxic to die kidneys, die nurse must carefully monitor fluid intake and output. In some instances, die nurse may need to perform hourly measurements of die urinary output. Periodic laboratory tests are usually ordered to monitor the patient s response to therapy and to detect toxic drag reactions. Seram creatinine levels and BUN levels are checked frequentiy during the course of therapy to monitor kidney function. If the BUN exceeds 40 mg dL or if the serum creatinine level exceeds 3 mg cIL, the primary health care provider may discontinue the drug therapy or reduce the dosage until renal function improves. 

The nurse must carefully monitor fluid intake and output because this drug may be nephrotoxic (harmful to the kidneys). In some instances, the nurse may need to perform hourly measurements of the urinary output. Periodic laboratory tests are usually ordered to monitor the patient s response to therapy and detect toxic drug reactions. 

The expected outcomes for the patient may include an optimal response to therapy, management of common adverse reactions, an absence of diarrhea, maintenance of an adequate intake of fluids, maintenance of adequate nutrition, an understanding of the therapeutic regimen (hospitalized patients), and an understanding of and compliance with the prescribed therapeutic regimen (outpatients). 

Discuss ways to promote an optimal response to therapy and important points to keep in mind when educating patients about the use of an electrolyte ora solution to manage body fluids. 

Promoting an Optimal Response to Therapy Fhtients receiving an IV fluid should be made as comfortable as possible, although under some circumstances this may be difficult. The extremity used for administration should be made comfortable and supported as needed by a small pillow or other device An IV infusion pump may be ordered for the administration of these solutions. The nurse sets the alarm of the infusion pump and checks the functioning of the unit at frequent intervals. 

If diuretic therapy is warranted, monitor for therapeutic response by assessing weight loss and improvement of fluid retention, as well as exercise tolerance and presence of fatigue. 

Acutely, diuretics lower BP by causing diuresis. The reduction in plasma volume and stroke volume associated with diuresis decreases cardiac output and, consequently, BP. The initial drop in cardiac output causes a compensatory increase in peripheral vascular resistance. With chronic diuretic therapy, the extracellular fluid volume and plasma volume return almost to pretreatment levels, and peripheral vascular resistance falls below its pretreatment baseline. The reduction in peripheral vascular resistance is responsible for the long-term hypotensive effects. Thiazides lower BP by mobilizing sodium and water from arteriolar walls, which may contribute to decreased peripheral vascular resistance. 

In multidrug therapy, it is necessary to consider which agents rationally complement each other. A p-blocker (bradycardia, cardiodepression due to sympathetic blockade) can be effectively combined with nifedipine (reflex tachycardia), but obviously not with verapamil (bradycardia, cardiodepression). Monotherapy with ACE inhibitors (p. 124) produces an adequate reduction of blood pressure in 50% of patients the response rate is increased to 90% by combination with a (thiazide) diuretic. When vasodilators such as dihydralazine or minoxidil (p. 118) are given, p-blockers would serve to prevent reflex tachycardia, and diuretics to counteract fluid retention. 

Fiuid and eiectroiyte baiance The use of this drug does not preclude the administration of appropriate fluid and electrolyte therapy. Dehydration, particularly in children, may further influence the variability of response and may predispose to delayed difenoxin intoxication. Drug-induced inhibition of peristalsis may result in fluid retention in the colon, and this may further aggravate dehydration and electrolyte imbalance. 

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