Critical Thinking Case

Mrs. S is a 28-year-old patient, with a 12-year history of type I diabetes mellitus. Her husband states that she has had a “bad cold” for several days. Yesterday she stayed in bed and slept all day. She was “too ill” to check her blood sugar, and since she was not really eating, she did not take her insulin. This morning, she was not able to stand up and vomited twice. A Gram stain of Mrs. S’s blood contains gram-positive cocci in clusters. Her admission vital signs are: BP = 90/60; HR = 118 bpm (sinus tachycardia); RR = 32/min; T = 102.3° F; O₂ sat via pulse oximetry = 96%. Her serum glucose is 398 mg/dl, and she is positive for serum ketones. She is admitted with a diagnosis of DKA. 

Her baseline ABGs on 2 L of oxygen are: pH = 7.25; PCO₂ = 28; HCO₃ = 14; PaO_{2 =} 92; O₂ sat = 96%. Her respirations are deep, rapid, and labored. She has bronchial breath sounds in the right axillary area. There is bilateral chest expansion and no evidence of cyanosis. 

A regular insulin bolus is given and a regular insulin drip is initiated. Mrs. S’s IV fluids are infusing at 800 ml/hr. Her vital signs after 2 hours in the unit are: BP = 120/70; HR = 78 bpm (normal sinus rhythm); RR = 22/min; O₂ sat = 100%. Her serum glucose is 250 mg/dl and serum potassium is 4.0 mEq/L. She is more alert and is feeling hungry. 

1. What is insulin’s function in the body? What is the most significant basic defect in the development of DKA? 
2. What is the cause of Ms. S experiencing DKA?  Describe the pathophysiologic rationale for your answer. 
3. List the classic signs and symptoms of DKA. Which signs and symptoms did Ms. S experience? What are the pathophysiologic causes of these signs and symptoms? 
4. What is an anion gap? Why is the anion gap important to follow in the treatment of DKA? 
5. What acid base disturbance is Ms. S experiencing? What compensatory mechanisms are in effect at this time? 
6. What is the primary nursing diagnosis for Ms. S.? What are the goals for treatment (both independent and collaborative)? What interventions are imperative to initiate immediately? What interventions are important within the next 12-24 hours? 
7. What are potential lab abnormalities for a patient in DKA? 
8. What nursing considerations are important in planning Ms. S’s discharge?