Fluid imbalance

When we RTs are called to assess a patient due to a low spo2, or increased crackles in the bases, or increased dyspnea as noted by the nurse, one of the #1 things to consider is if the patient is wet.

For the record, normal urine output is 1-2 liters per day, or 25-50 ml/hr. Likewise, a patient's normal fluid balance is a measure of fluid intakes mainly form drinking or through the IV. It is my observation that fluid overload is quite often overlooked by the nurse.

I say this with no disrespect to nurses. We, as RTs, are a part of the patient care team. If the nurse (or the physician) does not pick up on the probable cause of the patient's symptoms, we RTs -- via our assessment and skills -- must pick it up.

Often, by being proactive, the teamwork and observant skills of the nurse and the respiratory therapist, or a combination of the two, can pick up on early signs of fluid overload and prevent a worsening condition from developing.

The best ways to assess for fluid overload is to assess the patient:

• drop in spo2
• dyspnea at rest (late sign) or with exertion (early sign)
• cyanotic
• diaphoretic
• audible wheezes (very common sign, and quite often mistaken for bronchospasm)
• auscultation: crackles or rhales in bases, should have good air movement if lungs are otherwise not compromised, COPD patients may sound diminished and may be hard to determine if there are crackles, may have coarse wheezes on inspiration and expiration that are heard well in throat (may be audible too).
• check flow sheet or nurses notes for urine inputs and outputs (i&o's). If the ins exceed the outs, or if there is a trend where the ins are exceeding the outs.
• IVs are set high
• patient is post operative (pt's are overhydrated during surgery)
• history if kidney (renal) failure
• history of CHF, pulmonary edema, heart surgery or other cardiac history
• COPD history, particularly late stage (they retain fluid due to right heart to left heart failure)
• old age
• end stage disease process
• peripheral edema
• hypertension

Of course you'll want to give the bronchodilator breathing treatment the nurse will recommend and the doctor will order, but then you provide the nurse and/or physician with your assessment. A good RT will get good at this rather within the first few weeks on the job.

We will continue to teach the following:

• Not all that wheezes is bronchospasm.
• Dyspnea is not always caused by bronchospasm
• Not all that causes dyspnea is bornchospasm
• Audible wheeze is not bronchospasm, it's secretions (or dehydration or inflammation)
• We RTs are open minded, and wrong sometimes

A negative fluid balance may also cause an upper airway wheeze that radiates throughout the lungfields and mimics a bronchospasm wheeze. A trained ear can tell the difference.

The following can cause negative output:

• insufficient hydration
• asthmatic (exacerbation)
• excessive urine output from meds (diuretics like lasix, bumex or xanthines like theophylline

Low urine output can result in:

• Hypotension (low cardiac output)
• upper airway wheeze
• severe vomiting (watch for electrolyte imbalance)
• diarrhea