residual volume


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Related to residual volume: inspiratory reserve volume, total lung capacity

volume

 [vol´ūm]
the space occupied by a substance or a three-dimensional region; the capacity of such a region or of a container.
blood volume the plasma volume added to the red cell volume; see also blood volume.
closing volume (CV) the volume of gas in the lungs in excess of the residual volume at the time small airways in the dependent portions close during maximal exhalation; see also closing volume.
deficient fluid volume a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as decreased intravascular, interstitial, and/or intracellular fluid. This refers to dehydration, water loss alone without change in sodium. See also fluid volume. Formerly called fluid volume deficit.



When a person engages in normal physical activity and the environmental temperature is 20°C (68°F), the body loses about 2400 ml of water in 24 hours. About 1400 ml are lost in urine, 200 ml in feces, and 100 ml in sweat. The remaining 700 ml are lost through what is called insensible water loss, which takes place by diffusion through the skin and by evaporation from the lungs. About 300 ml of water diffuse through the epithelial cells daily. The lungs excrete about 400 ml per day.

A deficit of fluid volume occurs when there is either an excessive loss of body water or an inadequate compensatory intake. Etiologic factors include active loss through vomiting, diarrhea, gastric suctioning, drainage through operative wounds and tubes, burns, fistulas, hypermetabolic states, and drug-induced diuresis. Insufficient intake of water can be caused by nausea, immobility with inaccessibility of water, and lack of knowledge about the necessity of adequate fluid intake.
Patient Care. Assessment of the patient's hydration status includes monitoring lab data for such signs as increased packed red blood cell volume, increased plasma protein level, elevated specific gravity of urine, and increased blood urea nitrogen (BUN) out of proportion to a change in serum creatinine. In the absence of other problems, the serum sodium should remain within normal limits.



Recording daily weight gives information about the amount of water gained or lost each day. If there is a fluid volume deficit, intake and output measurements can give evidence of fluid imbalance. The urine appears concentrated and is usually well below the criterion of 50 ml of output per hour. Other objective assessment data include hypotension and a decrease in venous filling and in pulse volume and pressure. The mucous membranes are dry, as is the skin, which loses its turgor. The patient may complain of thirst and the body temperature may be elevated.

Patients at risk for profound and potentially fatal fluid volume deficit, as in severe burns, should be assessed frequently for mental acuity status and orientation to person, place, and time. Measures to improve hydration status should take into account the patient's ability to drink and retain fluids by mouth, preferences for certain fluids, and whether hot or cold drinks are preferred. The goal of oral fluid intake should be about 2000 ml per day. Explanations about the importance of an adequate fluid intake and assuring the availability of fresh water and fluids attractive to the patient can help reach the desired goal. Intravenous administration of fluids, especially isotonic saline, may be necessary if oral replacement is not possible. In severe and intractable fluid volume deficit a central venous catheter may be used to evaluate the extent of fluid loss and to guide replacement therapy.
excess fluid volume a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as increased isotonic fluid retention; see also fluid volume. Factors contributing to this include (1) arterial dilatation, as occurs in the inflammatory process; (2) reduced oncotic pressure, as in hypoproteinuria (particularly a deficit of albumin, which is responsible for 80 per cent of oncotic pressure), lymphatic obstruction, and increased capillary permeability, which allows water to escape into the tissues and produce swelling; (3) renal retention of sodium and consequently of water, as seen in renal failure; (4) inadequate circulation of blood through the general circulation, as in congestive heart failure, or through the portal circulation, as in liver failure; and (5) overproduction or administration of adrenocortical hormones.



Hypervolemia can occur when a patient receives excessive fluid replacement or repeated tap water enemas or, much less frequently, drinks more fluids than are eliminated. Characteristics of fluid volume excess include obvious swelling, localized or generalized; weight gain; pulmonary congestion with accompanying shortness of breath, orthopnea, and abnormal breath sounds; a fluid intake greater than output; distended neck veins; and changes in central venous and pulmonary artery pressures.
expiratory reserve volume the maximal amount of gas that can be exhaled from the resting end-expiratory level.
fluid volume the volume of the body fluids, including both intracellular fluid and extracellular fluid.
forced expiratory volume (FEV) the volume that can be exhaled from a full inhalation by exhaling as forcefully and rapidly as possible for a timed period. Times are denoted by subscripts, such as FEV0.5, FEV1.0, FEV2.0, and FEV3.0 for FEV values for 0.5, 1, 2, and 3 seconds.
inspiratory reserve volume the maximal amount of gas that can be inhaled from the end-inspiratory position.
mean corpuscular volume (MCV) the average volume of erythrocytes, conventionally expressed in cubic micrometers or femtoliters (μm3 = fL) per red cell, obtained by multiplying the hematocrit (in l/L) by 1000 and dividing by the red cell count (in millions per μL): MCV = Hct/RBC. Automated electronic blood cell counters generally obtain the MCV directly from the average pulse height of the voltage pulses produced during the red cell count. These instruments obtain the hematocrit indirectly from the equation Hct = MCV × RBC.
minute volume (MV) the quantity of gas exhaled from the lungs per minute; tidal volume multiplied by respiration rate.
packed-cell volume (PCV) hematocrit.
plasma volume the total volume of blood plasma, i.e., the extracellular fluid volume of the vascular space; see also blood volume.
red cell volume the total volume of red cells in the body; see also blood volume.
residual volume (RV) the amount of gas remaining in the lung at the end of a maximal exhalation.
risk for deficient fluid volume a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as being at risk for vascular, cellular, or intracellular dehydration. See also deficient fluid volume.
stroke volume the quantity of blood ejected from a ventricle at each beat of the heart; called also stroke output.
tidal volume the amount of gas passing into and out of the lungs in each respiratory cycle.

re·sid·u·al vol·ume (RV),

the volume of air remaining in the lungs after a maximal expiratory effort.

residual volume (RV)

Etymology: L, residuum, remainder, volumen, papyrus roll
the amount of air remaining in the lungs at the end of a maximum expiration.

re·sid·u·al vol·ume

(RV) (rē-zid'yū-ăl vol'yūm)
The volume of air remaining in the lungs after a maximal expiratory effort.
Synonym(s): residual air, residual capacity.

residual volume

The volume of air remaining in the lungs after maximal expiration.

residual volume

or

reserve volume

the air remaining in the lungs after respiration, with a volume of about 1200ml. see VITAL CAPACITY.

re·sid·u·al vol·ume

(RV) (rē-zid'yū-ăl vol'yūm)
The volume of air remaining in the lungs after a maximal expiration.
Synonym(s): residual capacity.
References in periodicals archive ?
Poor validity of residual volumes as a marker of aspiration in critically ill patients.
For example, when the volume down from TLC is measured, rather than using the commonly used method of measuring up from residual volume, most often very different results are obtained.
Ironically, inappropriately low gastric residual volume cut-offs to define enteral feeding protocols have been shown to result in unnecessary enteral feed stoppages, a phenomenon that was correlated with an increased incidence of infection and nosocomial pneumonia compared with patients who received significantly higher enteral formula volumes.
Gastric residual volume and aspiration in critically ill patients receiving gastric feedings.
7] This presents as higher than desirable gastric residual volumes of gastric secretions in the fasted patient and of enteral feed in the fed patient, and possibly also with vomiting in patients with large retained volumes in the stomach; this may be worsened by abnormal pyloric responses to feeds and persistent duodenal contractile motor waves that propagate in the wrong direction, provoking reflux from the duodenum in a retrograde fashion into the stomach.
Training had a slight impact on the residual volume for Syringe C and for PFS, although the residual volumes were not statistically different (there was a slight decrease in non-injected volume after training for PFS and Syringe C).
Indeed, the FDA recommends performing a comparative evaluation of the residual volume with and without the safety feature.
The patient is turned into the re-breathing bag at the end of an exhaled maximum breath or at residual volume, and the re-breathing continues for four minutes.
Three months following catheter removal, he feels well has no significant residual volume and a negative urine culture.
The study found no differences between groups in postvoid residual volumes, prostate-specific antigen levels, total prostate volumes, or transition zone volumes.
The new microplate washer achieves its high wash performance by having very low residual volumes (less than 2 il) and multiple aspiration points for each well.
Quantitation of urinary flow rates and postvoid residual volumes may be helpful in predicting response to therapy in selected patients, but there are no established cutoff abnormal values.