Mrs. Ford is a 32 year old female who was admitted to the neuro ICU two days ago after a fall, which caused a large epidural hematoma over the left parietal lobe. She was intubated due to a low level of consciousness to protect her airway. An External Ventricular Drain (EVD) was placed to monitor her ICP. She also has an orogastric tube, and a Foley catheter in place
Critical Thinking Check
Bloom's Taxonomy: Application
You just started your shift, what nursing assessments will be your priority at this point?
VIEW ANSWER
Assess ventilator and respiratory status, lung sounds, SpO2
Assess EVD system for integrity and that it is draining appropriately
Complete neuro exam including pupils, GCS, reflexes, and LOC.
Full set of vitals plus assessing IV sites for signs of infiltration or infection
Assessing foley site and urine output
Turning and assessing skin top to tail
Mrs. Ford’s vital signs are as follows: BP124/68MAP86
HR84Temp 98.9 RR16 (ventilated) ICP12
She is not on any sedation. You determine her GCS is 6, she withdraws to pain, but does not open her eyes. Her pupils are equal and reactive bilaterally, 4mm. For this hour she has put out 120 ml of urine that is clear and yellow. She is receiving normal saline at 75 mL/hour as well as tube feeds at 40 mL/hour. Her EVD is open at 15 cmH2O and draining a clear pink fluid, 6 ml this hour.
faq lesson=”true” blooms=”Application” question=”Calculate her cerebral perfusion pressure.”]
CPP = MAP – ICP
86 – 12 = 74 mmHg [/faq]
Critical Thinking Check
Bloom's Taxonomy: Analysis
Given the assessment information that you have, what are you most concerned for with this patient?
VIEW ANSWER
Immobility – skin and muscle breakdown
Increased ICP → herniation → death
Seizures
Damage to Pituitary and/or Hypothalamus glands → can cause SIADH, DI, temperature regulation issues, as well as issues with CNS functions like breathing
This patient clearly has a significant brain injury. I would be concerned for and monitoring for the following complications:
Hourly urine output for Mrs. Ford For the last 3 hours were 180 mL, 240 mL, and 440 mL. The urine is clear and barely pale yellow. Her blood pressure is 108/56, HR is 104. Her ICP is 15.
Critical Thinking Check
Bloom's Taxonomy: Analysis
What could be going on physiologically with Mrs. Ford?
VIEW ANSWER
This is likely Diabetes Insipidus due to the known neurological issue and the excessive output of clear, barely pale yellow urine.
Neurological damage can cause damage to the pituitary gland – causing a LACK of secretion of ADH (Antidiuretic Hormone). This means the patient can no longer retain water and therefore begins to dump water excessively – this is why the urine looks almost like water.
This will cause the blood to be super concentrated and could cause a lot of other issues because of it.
Critical Thinking Check
Bloom's Taxonomy: Analysis
What further diagnostic testing do you expect the provider to order?
VIEW ANSWER
Note: Polyuria WITHOUT hyperosmolality may indicate Primary Polydipsia – a condition in which patients literally drink water excessively and send themselves into a water intoxication/hypernatremic state.
Check a CMP with serum osmolality to see if she is hyperosmolar or hypernatremic
Check urine specific gravity and urine osmolarity – again this can tell us if she’s dumping lots of urine or if she’s just dumping a ton of water. Low specific gravity indiacates DI.
Explain the significance of these lab values considering the patient's diagnosis.
VIEW ANSWER
The patient is dumping excessive amounts of water in the urine, that is why her urine specific gravity is so low
Because of the loss of water, the blood is now super concentrated, creating hypernatremia and a high serum osmolality.
Critical Thinking Check
Bloom's Taxonomy: Analysis
What medications and or treatment changes do you expect the provider to order?
VIEW ANSWER
The IV fluids need to be changed to D5W or D10W
Free water via the OG tube will also help with the sodium levels
DDAVP (Desmopressin) or Vasopressin should be ordered to replace the ADH that isn’t working
The provider orders the following:
Free water flush via OG Tube – 200 mL q4h
Change IVF to D5W at 125 mL/hr
Desmopressin (DDAVP) 2 mcg IV push q 12h
Daily weight
q4h Sodium and Serum Osmolality levels
You set the tube feeding pump to administer the free water and change the IV fluids while waiting for the DDAVP from the pharmacy
Critical Thinking Check
Bloom's Taxonomy: Analysis
What regular monitoring will need to be done for Mrs. Ford during this treatment?
VIEW ANSWER
Hourly urine output + urine specific gravity
Continue frequent monitoring of vital signs and ICP/CPP
Re-draw labs as ordered to ensure sodium is not being corrected too quickly
After 2 days of treatment, misses Fords urine output and urine specific gravity return to Baseline. However, she continues to have a GCS between 4 + 6, and now her left pupil is 8mm and fixed. The nurse notes her respiratory rate is erratic, her ICP is 18, and her heart rate is dropping.
Critical Thinking Check
Bloom's Taxonomy: Analysis
What do you believe could be happening to Mrs. Ford at this time?
VIEW ANSWER
Mrs. Ford may be experiencing brain herniation due to the bleeding and swelling in and around her brain
Unfortunately, many times these patients cannot be returned to their normal baseline due to the extent of the damage.