Water Balance (BH) is the relationship between income and bodily losses . Since ions (electrolytes) are diluted in the volume (hydro ) we speak of the hydroelectrolyte balance .
Calculation of the water balance
In order to calculate the water balance , income and bodily losses are quantified in different ways to establish a balance in a given period of time no longer than 24 hours.
It is usually measured in patients who are in intensive care (ICU) with kidney and heart problems, with loss of fluid volume, blood or electrolytes.
Types of Water Balance
- Normal: When the daily intake of fluids is equal to those eliminated.
- Positive: When the daily intake of liquids is greater than those eliminated.
- Negative: When the daily intake of liquids is less than those eliminated.
Depending on the time in which the water balance is quantified, it can be classified into
- Partial: When income and losses are counted in a time interval, example in 6 hours.
- Total: When done in a 24-hour period.
Procedure to measure water balance
- Prepare the BH record sheet with the patient’s data .
- Select the measuring instruments.
- Have devices with a measuring ruler as the case may be.
- Carry out the procedure with the use of universal protections ( gloves , hat , mask , etc.)
- Measure the amounts of fluids administered to the patient by the different routes:
- Enteral: diets, commercial preparations, water , juices , and other beverages .
- Parenteral: According to the treatment guideline, medications and serum therapy through central and peripheral venous routes.
- Measure the amounts of fluids eliminated by different routes, urinary, catheters , surgical , thoracic drains , ostomies , etc.
- Quantify insensitive losses, vomiting, sweating, breathing, etc.
- Check that the containers are completely empty, as the wells from previous measurements would distort the results in terms of quantity and assessment of the drainage characteristics.
- Outline the amounts of fluids administered and ingested on the patient’s chart.
- Program the enteral or parenteral infusion pumps correctly according to the indicated schedule.
- Record the results on the BH sheet.
Water Balance Sheet
This record sheet is the responsibility of the nursing staff and allows detecting possible changes in the fluid and electrolyte balance and establishing guidelines in the treatment that will be provided to the patient. Generally it is quantified in 24 hours, registering the income and expenses of liquids in shifts and making a summation at the end of this period of time.
Interpretation of the Water Balance Result
The results obtained allow the doctor to precisely adjust not only the volume, but also the quantity and quality of the ions, to avoid metabolic decompensations that would aggravate the patient’s pathology . Water imbalance is the existence of abnormally low or high volumes of the total body fluids and can lead to a compromise of the state of health of an individual and be especially risky in people of extreme ages or with acute pathologies.
Result of the water balance
The result of the water balance can be Hydration or Dehydration . This result can be related to:
- Excess volume ( Edema )
- Fluid retention.
- Increase in sodium intake, which causes greater retention of body water.
- Rapid and exaggerated delivery of intravenous volumes.
- Volume deficit (Dehydration)
- Excessive fluid loss caused by vomiting , diarrhea , drainage .
- Decreased intake.
- Bleeding
- Use of diuretics.
- Febrile states.
- It can also be related to:
- Balance AB.
- Tachycardia. Increased blood pressure or central venous pressure (CVP).
- Increased urinary flow.
- Displacement of liquids to a third space: ascites , extensive and / or deep burns , internal bleeding in cavities or joints.
Mechanisms that maintain the water balance:
The homeostasis of the total volume of water is maintained in the body mainly by mechanisms that adjust excretion with intake and secondarily, by mechanisms that adjust said intake.
The infants , patients with neurological or psychological disorders and some elderly are unable to perceive or respond to the thirst mechanism, taking risk of electrolyte imbalances.
Water imbalances
It is the existence of abnormally low or high volumes of the total body fluids. Water imbalances can lead to a compromise of the health status of an individual and be especially risky in people of extreme ages, with acute and / or chronic diseases such as cardiac, kidney, respiratory or hemodynamic instability states .