Question

Kevin Harney, age 14, did not appear for breakfast when his mother called him. “That's unusual,” she thought. “He has been so hungry lately. And he is so skinny, he really needs the food!” She found Kevin lying on his bed, breathing rapidly and deeply. He responded slowly with one or two words at a time to her increasingly frantic questions. Some of his answers did not make sense. Kevin's parents took him to the nearest emergency department, where his laboratory tests showed arterial blood pH 7.20, Paco2 21 mm Hg (2.8 kPa), serum concentration 8 mEq/L (8 mmol/L), and glucose concentration 450 mg/dL (25 mmol/L). Kevin was diagnosed with diabetic ketoacidosis (DKA) arising from previously undiagnosed type 1 diabetes. During Kevin's hospitalization, interventions focused initially on intensive collaborative management of his disrupted acid-base balance with insulin and IV fluid to treat the diabetes. As a safety intervention, Kevin was positioned on his side to prevent aspiration if he vomited. During this phase of management, attention also was given to supporting his parents, explaining that Kevin's unusual breathing pattern actually was beneficial to him and letting his mother assume the task of protecting Kevin's lips by keeping them lubricated. Careful monitoring of blood values and physical assessment parameters was used to follow his progress and modify therapy when his condition changed. As Kevin began to be more responsive and stable, the focus of nursing interventions expanded to teaching Kevin and his parents about type 1 diabetes, how to manage it, and how to recognize the signs of hyperglycemia. Although not directed specifically at acid-base balance, this teaching helped prevent future episodes of diabetic ketoacidosis through disease management. Case Analysis Kevin developed diabetic ketoacidosis, a type of metabolic acidosis (too much metabolic acid), from a combination of excessive production and decreased excretion of metabolic acid. Because of his type 1 diabetes, Kevin's pancreas no longer was able to secrete insulin. The resulting metabolic problems included hyperglycemia and incomplete metabolism of fat that generated large amounts of ketoacids (increased acid production). Although Kevin did not have kidney disease, his kidneys were unable to excrete enough ketoacids to prevent their accumulation. An initial osmotic diuresis from hyperglycemia often decreases the extracellular fluid volume (ECV) and decreases glomerular filtration rate, causing oliguria when the ECV becomes low. Oliguria decreased the excretion of the ketoacids, contributing to their accumulation. As his blood pH decreased, Kevin's chemoreceptors triggered compensatory hyperventilation. Kevin's arterial blood gas values demonstrate his disrupted acid-base balance: decreased pH (acidosis from too much acid), decreased Paco2 (carbonic acid removed by compensatory hyperventilation), and decreased concentration (used in buffering the excess metabolic acids). Interventions directed at treating Kevin's diabetes and promoting safety, comfort, and teaching provided effective care.

Questions

1. In terms of acid-base balance, what is your interpretation of Kevin’s rapid, deep breathing?

2. What arterial blood gas values would indicate that Kevin had regained acid-base balance?

Answer 1

1-The patient is said to be suffering a metabolic acidosis in DKA.Blood gas analysis at this stage revels redused ph combination with reduced bicarbonate concentration.In severe DKA pH may fall below 7.0 and bicarbonate below 10 mmol/L.Here the patient having blood values like metabolic acidosis.Deep and labourd breathing pattern often assosiated with severe metabolic asidosis,particularly diabetic keto acidosis.in metabolic acidosis breathing is first rapid and shallow but as acidosis worsens breathing gradually becomes deep laboured and gasping.

2.pH should be between 7.35-7.45

Pao2- 75-100mmHg

PaCo2 35-45mmHg

Bicarboante 22-26mEq/L