wagner6_ch24_case_study_answers.docx

Chapter 24: Determinants and Assessment of Fluid and Electrolyte Balance Critical Thinking Checkpoint Case Studies Donald R., 75 years old, was admitted to the hospital with severe dyspnea. He has a history of chronic alcohol abuse and cirrhosis. On admission, the nurse assesses the following: thin, chronically ill-appearing male. Blood pressure 108/62 mm Hg; pulse 118/min.; RR 26/min.; temperature 97.8°F (36.6°C). He has 3+ pitting generalized edema. His abdomen is distended and tight. He has orthopnea and complains of shortness of breath. Mr. R. states that he has been confined to his chair or couch for the past 2 weeks because of his breathing difficulty and general weakness. This activity contains 5 questions. 1. Identify factors in Mr. R.'s history that affect his fluid and electrolyte balance. What additional data would be important to elicit? Answers: A nursing history is an essential component of an assessment of fluid and electrolyte balance in the high-acuity patient. Questions that should be asked include: Does the patient have an injury or disease process that can alter fluid and electrolyte balance? Mr. R. has cirrhosis. This can cause altered fluid and electrolyte balance, as there is increased fluid in the peritoneal cavity and less fluid in the intravascular compartment. This is why he is hypotensive. Does the patient have dietary restrictions that can alter fluid and electrolyte balance? Mr. R.'s abdominal distention and shortness of breath may cause nausea, vomiting, and decreased appetite. All of these conditions impair intake of fluids and electrolytes. Additional information that would be helpful to elicit: Is the patient receiving any medications that can alter fluid and electrolyte balance? How does the total intake of fluids compare with the total output of fluids? If there an imbalance, what is the imbalance and how long has this imbalance occurred? 2. Given Mr. R.'s vital signs, what vital sign changes would support the presence of orthostatic hypotension? Answer: Orthostatic vital sign measurement can be used to assess for dehydration, blood loss, and the effects of antihypertensive medications. Orthostatic hypotension is defined as a drop in blood pressure of more than 20 mm Hg or an increased in heart rate greater than 20/min. when going from a lying to sitting or sitting to standing position. Mr. R.'s current BP is 108/62 mm Hg and HR is 118/min. If Mr. R had orthostatic hypotension, his BP would decrease to 88/42 mm Hg and his pulse would increase to 138/min. 3. Mr. R. has generalized edema. Compare and contrast the pathophysiologic causes of generalized versus localized edema. Answer: Determining whether the edema is localized or generalized gives important clues as to its possible origin because pathologic conditions are usually associated with one or the other. Generalized edema is present all over the body and is primarily seen in the presence of decreased plasma proteins resulting from severe protein malnutrition. This is the case with Mr. R. Localized edema results from a more localized pathologic condition-for example, local inflammation and infection. Localized edema is confined to areas in which the causative condition is affecting the capillaries or lymph tissues (e.g., the area of inflammation, obstruction, or high capillary hydrostatic pressure). The edema associated with heart failure is considered localized because it is confined to the gravity-dependent body areas (e.g., feet, lower legs, and sacrum). Pulmonary edema caused by left-sided heart failure is localized edema created by increased capillary hydrostatic pressure in the lungs as a result of elevated left heart pressures. 4. What is the relationship between albumin and total calcium? Answer: Total calcium reflects calcium that is bound to albumin. If albumin is low, then serum calcium levels will be low. 5. Mr. R. has a BUN of 40 mg/dL and a Cr of 4.0 mg/dL. Calculate his BUN-to-Cr ratio. What is your interpretation of these results? Answer: 40/4 = 10:1. BUN and Cr are both elevated and the ratio remains at 10:1. The etiology is likely to be renal tubule dysfunction.