A Nasogastric (NG) tube is inserted preoperatively and is attached to low, intermittent suction. A client with an NG tube exhibits these symptoms: He is restless; serum electrolytes are Na 138, K 4.0, and blood pH 7.53. This client is most likely experiencing?

Appeared in: NORCET 5 mains

Explanation

Nasogastric (NG) suction removes hydrochloric acid from the stomach.
This loss of hydrogen ions (H+) causes the blood to become more alkaline, leading to a pH above the normal range of 7.35-7.45.
The client's blood pH of 7.53 is elevated, confirming a state of alkalosis.
Because the cause is the loss of stomach acid (a metabolic process, not a respiratory one), the condition is correctly identified as metabolic alkalosis.
Restlessness is a neurological symptom that can manifest with significant acid-base imbalances like metabolic alkalosis.

Option A: The client's serum potassium level is 4.0 mEq/L, which is within the normal range (typically 3.5-5.0 mEq/L). Hyperkalemia is defined as an elevated potassium level.
Option B: The client's serum sodium level is 138 mEq/L, which is within the normal range (typically 135-145 mEq/L). Hyponatremia is defined as a low sodium level.
Option C: This condition is characterized by a low blood pH (below 7.35) due to an excess of acid or loss of bicarbonate. The client's pH is high (7.53), indicating alkalosis.

Visual 1: Flowchart: Pathophysiology of Metabolic Alkalosis from NG Suction. This visual would trace the pathway from the loss of HCl in the stomach to the resulting increase in serum bicarbonate and elevated blood pH.
Visual 2: Chart: Normal Arterial Blood Gas (ABG) Values. A simple reference chart showing the normal ranges for pH, PaCO2, and HCO3 helps in quickly identifying deviations like the one in the question.

Clinical Relevance

Nursing practice connection: Knowing Metabolic Alkalosis from Nasogastric Suction helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses must diligently monitor clients with NG suction for early signs of metabolic alkalosis, including restlessness, confusion, muscle twitching, and changes in vital signs.
It is a critical nursing responsibility to check electrolyte and ABG lab results promptly and report any deviations to the healthcare provider for timely intervention.
What if? If the client was experiencing severe diarrhea instead of NG suction, the most likely diagnosis would be metabolic acidosis. This is because diarrhea causes a loss of bicarbonate-rich fluid from the lower gastrointestinal tract, leading to a decrease in blood pH.

How to Approach the Question

First, analyze the primary intervention and clinical context. The client has an NG tube on suction, a major clue pointing towards the loss of gastric acid.
Next, evaluate the key laboratory value: the blood pH. A pH of 7.53 is significantly higher than the normal upper limit of 7.45, which immediately indicates a state of alkalosis.
Based on the high pH, you can confidently eliminate any 'acidosis' options. This rules out 'Metabolic acidosis'.
Now, examine the electrolyte levels. The sodium (138 mEq/L) and potassium (4.0 mEq/L) are both within their normal ranges. This allows you to rule out 'Hyponatremia' and 'Hyperkalemia'.
Finally, synthesize the findings. The only remaining option is 'Metabolic alkalosis', which perfectly aligns with the clinical picture of acid loss from NG suction leading to an elevated blood pH.

Concept Tested & Keywords

Concept Tested: Metabolic Alkalosis from Nasogastric Suction
Stem keywords: Nasogastric (NG) tube, low, intermittent suction, restless, serum electrolytes, blood pH 7.53
Lead-in keywords: most likely experiencing
Clinical cues: pH 7.53 (indicates alkalosis)
Clinical cues: NG suction (known cause of acid loss)

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