Maintenance fluids

Concentrate intravenous medications ° Evaluate maintenance fluids ° Concentrate parenteral nutrition 0 Use concentrated enteral nutrition products Avoid and/or discontinue nephrotoxins wherever possible... 

Calculate the daily maintenance fluid requirement for patients given their age, weight, and gender. 

Once TBW has been restored, the volume of maintenance fluid equals the basal fluid requirement plus ongoing exceptional losses. If the pathophysiologic process leading to TBW depletion has not been identified and corrected (or accounted for in the calculation of maintenance fluid requirements), TBW depletion will quickly recur. To review the concepts involved in the calculation of replacement fluids for a representative patient (see Patient Encounter 2). 

TABLE 24-2. Useful Calculations for the Estimate of Patient Maintenance Fluid Requirements... 

In patients with peritonitis, hypovolemia is often accompanied by acidosis, so large volumes of a solution such as lac-tated Ringers may be required initially to restore intravascular volume. Maintenance fluids should be instituted (after intravascular volume is restored) with 0.9% sodium chloride and potassium chloride (20 mEq/L) or 5% dextrose and 0.45% sodium chloride with potassium chloride (20 mEq/L). The administration rate should be based on estimated daily fluid loss through urine and nasogastric suction, including 0.5 to 1.0 L for insensible fluid loss. Potassium would not be included routinely if the patient is hyperkalemic or has renal insufficiency. Aggressive fluid therapy often must be continued in the postoperative period because fluid will continue to sequester in the peritoneal cavity, bowel wall, and lumen. 

PN generally should not be used to treat acute fluid abnormalities. Rather, PN should be adjusted to minimize worsening of underlying fluid disturbances, taking into account other fluids the patient is receiving. Daily maintenance fluid requirements for adults can be estimated with the following equation ... 

Fluid Adjust PN to provide minimal amount of fluid, then take into consideration other fluid sources (e.g., other IV fluids) and adjust to meet daily maintenance fluid needs Safer and more cost-effective to adjust IV fluids rather than PN 1 500 mL + (20 mL/kg x 40 kg) = 1 500 mL + 800 mL = 2300 mL/day... 

Two classes of polyionic fluid are available, those for resuscitation and those for maintenance. Maintenance fluids (Normosol-M), Plasma-lyte M, Plasmalyte-56, contain higher potassium (15-30 mEq/1 (15-30 mmol/1)) and lower sodium (40-60 mEq/1 (40-60 mmol/1)) and chloride (40-60 mEq/1 (40-60 mmol/1)) concentrations than resuscitation fluids (Normosol-R), Plasma-lyte 148, Isolec, lactated Ringer s solution. Currently, maintenance fluids are not available commercially in volumes of greater than 1 liter, which has led to the practice of adding potassium chloride (at 10-20 mEq/1) to resuscitation formulas so that they can be used as maintenance fluids in equine medicine. Commercial maintenance fluids should be considered as a treatment option in equine neonates. 

Maintenance fluid therapy, acute fluid resuscitation, edema Burn patients, edema... 

Crystalloids Crystalloids are replacement and maintenance fluid therapy. These include dextrose,... 

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). 

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. 

Central PICC line placed with maintenance fluids ... 

Box 2 Hourly Maintenance Fluid Infusion Calculation (Using 4-2-1 Formula)... 

Example For a 25-kg child, the maintenance fluid rate would be ... 

Dehydration may also result if the patient does not drink plenty of water during the treatment. Specifically it is recommended that a child drink (or be given intravenously) one and a half times maintenance fluids. That amount is determined according to the age and weight of the child. ... 

Corrosion problems on commercial aircraft are the result of combinations of factors whose causes can be found in the basic design, manufacturing, and operations of the aircraft. Some of these factors are summarized in Table 1 (manufacturer), and Table 2 (operator and service environment). These present unique problems to the manufacturer who must make the best design, materials, and process choices that are compatible with structural requirements and the economics of building and operating an airplane. In order to achieve these ends, corrosion testing must help establish requirements for structural materials and compatible finish systems, as well as a host of manufacturing aids, interior materials, and operational maintenance fluids that will... 

Maintenance fluids Resistance to general corrosion Deionized, distilled... 

Maintenance fluids Resistance of selected aerospace None—Allowable weight... 

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