Question

Patient Profile: Mr. T., a 73-year-old man who lives alone, is admitted to the hospital because of weakness and confusion. He has a history of chronic heart failure and chronic diuretic use.

Objective Data:

• Neurologic: Confusion, slow to respond to questioning, generalized weakness
• Cardiovascular: BP 90/62, HR 112 and irregular, peripheral pulses weak; ECG indicates sinus tachycardia
• Pulmonary: Respirations 12/min and shallow
• Additional findings: Decreased skin turgor; dry mucous membranes

Significant Lab Results:

Serum electrolytes

• Na+ 141 mEq/L
• K+ 2.5 mEq/L
• Cl- 85 mEq/L
• HCO3- 43 mEq/L

BUN 42 mg/dl

Hct 49%

Arterial blood gases

• pH 7.52
• PaCO2 55 mmHg
• PaO2 88 mmHg
• HCO3- 42 mEq/L

Critical Thinking Questions

1. Evaluate Mr. T’s fluid volume and electrolyte status. Which physical assessment findings support your analysis? Which lab results support your analysis? What is the most likely etiology of these imbalances?

2. Explain the reasons for Mr. T’s ECG changes

3   Analyze the arterial blood gas results. What is the etiology of the primary imbalance? Is the body compensating for this imbalance?

4 Why has Mr. T’s advanced age placed him at risk for his fluid imbalance?

5. Discuss the role of aldosterone in the regulation of fluid and electrolyte balance. How will changes in aldosterone affect Mr. T’s fluid and electrolyte imbalances?

Answer 1

1.He has fluid electrolyte imbalance.He is hypovolemic,hypokalemic and has metabolic alkalosis.

The physical examination findings which support the bhypovolemia is the hypotension(90/62mmhg),tachycardia(112beats/minute) , the weak peripheral pulse and the shallow respiration,decreased skin turgor and the dry mucous membrane.

The l;ab result supporting the analysis is the value of pottasium and the value of chloride,these two can occur as aresult of hypovolemia.

The etiology of this fluid electrolyte imabalance is the fluid loss.It can be because of vomiting,diarrhoea,poor fluid intake,decreased cardiac output and use of certain medications like diuretics.In this case it is clearly mentioned that he has chronic heart failure and has chronic use of diuretics.

2) The main reaason for the changes in ECG is the chronic heart failure,Low HCt and low blood pressure.hypokalemia(Electrolytes are necessary for the proper functioning and for the proper conduction of the heart.When there is hypokalemia and hypochloremia it can affect the electrical impulse of the heart and can cause tachycardia) .

3). The ABG value shows the metabolic alkalosis(increased ph and high bicarbonate concentration.)The main reason fro his condition is the chronic use of diuretics,which intuirn caused the hypokalemia and the metabolic alkalosis.

Here the respiratory compensation is happening by slowing down the respiration to retain the carbondioxide.(partial compensation)

4) Age related decrease in the thirst sensation,decreased mental status (delirium),altered level of hormones which is responsible for th fliud electrolyte balance

5)Aldosterone is the main meneralocorticoid secreted by the adrenal gland,resposnsible for the fluid and electrolyte balance in our body.It stimulates the water and the sodium reabsorpion in the kidney(renal collecting duct) and to increase the potasium excretion in the kidneys.aldosterone may act on the central nervous system via the posterior pituitary gland to release vasopressin (ADH) which serves to conserve water by direct actions on renal tubular resorption.

Changes (increase) in al;dosterone can regulate the water reabsorption in the kidney,also it may work on the central nervous system to stimulate the pitutary gland to produce ADH,there by it can maintain the fluid electrolytre balance in his body.