module 10 case study

Question 1

Identify the signs that specifically indicate that Ms. Bales is experiencing some degree of renal injury.

Answer 1

Increased BUN & creatinine

Question 2

Explain why glomerulonephritis can be ruled out as a cause of renal injury in this case

Answer 2

No protein in urine

Question 3

If Ms. Bales produces 132 ml of urine over the first 6 hours after her admission, into which category of the RIFLE system does she fall? (Refer to RIFLE table on slide 17. Show your calculations: how many ml/h is she producing? How many ml/ h (over a 6 h period) would signify a category of risk for a person of her weight?). What is the medical term for the amount of urine that she is producing?

Answer 3

Risk: measure urine over 6 hours (injury: measure over 12 hours) 54kg/2 = 27mL/hr - should be making that amount… she made 132/6 hours = 22mL/hr she is at risk (oliguria)

Question 4

Based on the described signs/symptoms, propose the cause of the acute kidney injury that Ms. Bales is experiencing (i.e., pre-, intra-, post- renal (include the definition of each cause)). Explain your conclusions with the use of abnormal signs/symptoms exhibited by Ms. Bales.

Answer 4

Pre = amount of blood given to kidney (low blood pressure) post = due to obstruction intra = something in the kidney . . . she has low blood pressure & low blood volume = pre

Pre-renal acute kidney injury is a sudden loss of blood flow to the kidney which results in loss of function of the kidney. Post-renal acute kidney injury is due to urinary tract disorders. Intra-renal acute kidney injury is due to tubular necrosis as a result of ischemia and sepsis. The cause of the acute kidney injury that Ms. Bales’ is experiencing is pre-renal acute kidney injury as her BUN to creatinine ratio is higher than normal (21 to 1). Another abnormal sign/symptom that is exhibited is her poor skin turgor with dry mucus membranes, which further proves that she has low perfusion due to hypovolemia.

Question 5

Calculate the BUN:creatinine ratio (i.e., value for BUN divided by value for creatinine) – does it support the conclusion of the previous question?

Answer 5

BUN value of 40mg/dL÷Creatine value of 1.9mg/dL=21.1mg/dL (21:1). The ratio is over 20 which is higher than normal and shows that there is kidney malfunction due to prerenal acute kidney injury, so this does support the conclusion of the previous question.

Question 6

Considering the information on slides 14 and 15, explain how BUN can increase to a greater degree than creatinine (thus causing an increased BUN:creatinine ratio) when the rate of flow through the kidneys decreases.

Answer 6

Kidney injury – both BUN & creatinine will go up in blood. But if BUN goes up even higher, there has been slower flow of filtrate through nephron. Urea is reabsorbed in nephron. Creatinine is not a slower rate of flow through nephron means more urea can be reabsorbed = increased amount of urea in blood

Question 7

What is the state of Ms. Bales’ sodium balance? Explain the resultant mechanism that could lead to her dizziness.

Answer 7

Hypernatremia – cells have shrunk

Question 8

Identify the type of pH imbalance from which Ms. Bales is suffering and explain your conclusion

Answer 8

Metabolic acidosis (pH down & CO2 down)

Question 9

What is Ms. Bales’ anion gap? Does the value agree with her condition? Explain

Answer 9

Na+ – (HCO3 + Cl-) = 147 – (20+115) = 12 which is normal anion gap therefore she is losing bicarbonate from body caused by diarrhea

Question 10

Is her pH balance corrected, compensated, partially compensated, or not compensated? Support your conclusion with facts from her case.

Answer 10

Lower than should be – partially compensated metabolic acidosis

Question 11

An examination of the laboratory results shows problems with which organ? On which results do you base your answer?

Answer 11

Kidney, increased urea, protein urine, decreased in size, increased creatinine, decreased GFR

Question 12

Is this an acute or a chronic issue? Assign the condition to a stage of the disease and state your reasoning. (2)

Answer 12

Chronic – takes time for kidneys to shrink, GRF is less than 30 (stage 3)

Question 13

What is a likely cause for injury to the organ affected? Describe one probable specific site of injury within this organ, and support why you have chosen this site

Answer 13

High blood pressure (hypertension)

Question 14

Below is a list of health issues from which Peter is suffering. Describe how they are brought about from malfunctioning of the kidney.

Answer 14

He has protein in urine = glomer

Anemia due to loss erythropoietin

Azotemia = increased nitrogenous waste products in the blood

Loss ability to remove potassium

Metabolic acidosis

Hormonal problem – calcitriol (hypocalcaemia)

Respiratory system will be trying to compensate for metabolic acidosis

Question 15

Peter’s kidneys have probably been decreasing in function for years. Why have signs and symptoms only shown up relatively recently?

Answer 15

Intact nephron hypothesis

Question 16

Does a calculation of Peter’s anion gap fit with the pathophysiology of his disease? Explain your conclusion

Answer 16

Anion gap: 145 – (107+20) = 18 (greater than normal) not able to get rid of hydrogen so building up acids inside body (Na – (HCO3+Cl-)

Question 17

What is the main effect of hypernatremia? a. Describe the three main causes of hypernatremia – understand and be able to apply the listed causes under each main cause. b. Be familiar with the overall clinical manifestations for hypernatremia, no matter what the direct cause is. c. Name the effect on blood volume as a result of each of the three ways that hypernatremia can occur. d. Understand the manifestations that result from each of these three ways.

Answer 17

Loss of both water and sodium, but more water. Symptoms: dehydration = hypovolemia (manifestations include hypotension, weight loss, tachycardia, weak pulse), DI or decreased intake of water = blood volume doesn’t change significantly (no loss of salt) = none of symptoms caused by changes in blood volume, retention of both water and sodium, but more sodium than water = hypervolemia (manifestations include weight gain, bounding pulse, increased blood pressure)

Thirst, alterations in membrane potential, shrinking of nerve cells (intracellular dehydration), confusion, coma and convulsions if becomes excessive

Question 18

What is the main effect of hyponatremia (on slide 7)? a. Describe the three main causes of hyponatremia – understand and be able to apply the listed causes under each main cause. b. Be familiar with the overall clinical manifestations for hyponatremia, no matter what the direct cause is. c. Name the effect on blood volume as a result of each of the three ways that hyponatremia can occur. d. Understand the manifestations that result from each of these three ways.

Answer 18

Loss of both sodium and water, but more sodium than water = hypovolemia (manifestations include hypotension, weight loss, tachycardia, weak pulse), SIADH or excessive intake of water = blood volume doesn’t change significantly (no loss of salt) = none of symptoms caused by changes in blood volume, retention of both sodium and water, but more water than sodium = hypervolemia (manifestations include weight gain, bounding pulse, increased blood pressure)

Most seriously affected are cells of the brain and nervous system (in addition to cell swelling, membrane potential is also altered), causing neurological alterations: confusion, depressed reflexes, seizures, coma