Case study 3

MSN5031: Differential Diagnosis and Collaborative Management in Acute Care

Case Study #3

Case Presentation

A Medical Intensive Care Unit (MICU) Acute Care Nurse Practitioner consult was called to

request evaluation of a 26-year-old female who the emergency department with altered mental

status and hyperglycemia, a fingerstick blood glucose (BG) of 405 mg/dL. The consulting

physician reports the patient has a history of hypertension, type 1 diabetes, and depression.

General Survey & History of Present Illness

The patient appears slightly older than her stated age and is somewhat disheveled in appearance.

The head of the bed is at 450 and the patient is sitting quietly with her eyes closed and head tilted

to the side. She is taking rapid, shallow breaths. I attempt to wake her, and she is able to be

aroused, but is groggy. I ask her to tell me her name, but she is unable to do so, and quickly rests

her head back on the pillow and closes her eyes. Her boyfriend, with whom she lives, is at the

bedside. I ask him to briefly update me on the duration of this-current illness, and any factors

that he is aware of that may have precipitated the event.

He explains that she has been feeling ill for the past 3 days. She had a "stomach virus" with

vomiting that worsened over the last 24 hours. She was unable to go to work for the last 3 days

and was so weak she could hardly walk. He explains that she "couldn't keep anything down." He

noted that she became much harder to arouse and was sleeping more over the last 12 hours, so he

decided to bring her to the emergency department. I ask if she has taken any medications recently

or taken any illicit substances, and he reports that he is not aware of her taking anything. He also

states that she has no history of substance abuse, or use of illicit drugs or alcohol.

Because of her history of type 1 diabetes and the fingerstick BG of 405 mg/dL, I ask about her

insulin regimen. Her boyfriend reports that she had an insulin pump, but "it broke about 6

months ago and she was having a hard time getting a new one." He states that she did see a

"diabetes doctor" and that she is now being managed with "a shot at night and then shots before

eating." I ask if she was taking her insulin as prescribed prior to admission, and he is not certain.

He says she has felt so poorly that she "probably didn't need it because she wasn't eating" and he

admits that he did not see her give herself an injection in a couple of days. He notes that he

usually-sees her inject her insulin right before bed, so this is unusual. He reports that he is not

aware that she has any health problems other than diabetes and does not take any prescribed

medications other than insulin.

During the time I am speaking with the patient's boyfriend, the nurse obtains another set of vital

signs: heart rate (HR) 124 beats per minute, blood pressure (BP) 90/53 mm Hg, respiratory rate

(RR) 30/m.in; Sa02 95% on room air. The nurse also obtains the patient's weight, which is 65 kg.

Laboratory Results

The ABG results are as follows:

Result Reference Range

pH 7.13 7.35-7.45

PaCO2 17 mmHg 35-45 mmHg

PaO2 96 mmHg 80-100 mmHg

HCO3 10 mEq/L 22-26 mEq/L

Lactic acid 6.1 mmol/L <2 mmol/L

The metabolic panel results are as follows:

Result Reference Range

Sodium 136 mEq/L 136-145 mEq/L

Potassium 5.5 mEq/L 3.5-5 mEq/L

Serum CO2 10 mEq/L 23-28 mEq/L

Chloride 100 mEq/L 98-106 mEq/L

BUN 35 mg/dL 8-20 mg/dL

Creatinine 2.0 mg/Dl 0.7-1.3 mg/dL

Magnesium 1.8 mg/dL 1.5-2.4 mg/dL

Phosphorus 5.8 mg/dL 3.0-4.5 mg/dL

Glucose 435 mg/dL Fasting 70-105 mg/dL

Albumin 4.1 g/dL 3.5-5 g/dL

Stabilizing the Patient

While drawing the labs, the nurse places two 18-gauge intravenous (IV) lines. I order a dose-of sodium bicarbonate (50mEq) intravenous push to stabilize the pH, although this will only serve as a temporizing measure until the underlying disorder is corrected. I order a stat intravenous bolus of regular insulin 9.75 units (0.15 units/kg) with a continuous infusion rate of 6.5 units/h (0.1 units/kg/h)3 and two liters of 0.9% normal saline to be given over 1 hour. I also order noninvasive positive pressure ventilation (NIPPV) in an effort to further reduce the PaC02, support her spontaneous breathing, and prevent fatigue and subsequent hypoventilation, which would further decrease her pH. If she were alert she would spontaneously hyperventilate; however, because she is somnolent, her respiratory compensation is inadequate to correct her pH. Ventilatory support is indicated.

The patient does rouse appropriately with stimulation and has cough and swallow reflexes, thus

I am confident she can protect her airway, which is essential for use of non invasive positive

pressure ventilation (NIPPV). NIPPV settings on a spontaneous mode of bilevel positive airway

pressure (ie, BiPAP) ventilation are ordered at an inspiratory positive airway pressure (IPAP) of

10cm H20 (this is pressure support ventilation [PSV]) and an expiratory positive airway pressure

(EPAP) of 5 cm H20 with 21% oxygen, since her oxygenation is normal. This type of NIPPV

assists the patient's spontaneous respiratory effort and decreases the work of breathing. I then

arrange for transfer to the medical intensive care unit.

Review of Systems

• Constitutional: Denies fever, increasingly tired and weak. Denies falls or trauma.

• Cardiovascular: Boyfriend is not aware of any cardiac disorders, arrhythmias, or coronary

artery disease.

• Pulmonary: Denies cough, but he notes her breathing changed prior to bringing her to the

emergency room.

• Gastrointestinal: Reports nausea, vomiting, abdominal pain, and occasional diarrhea

which began about 72 hours ago. Minimal oral intake with at least 5 episodes of vomiting

in the last 24 hours.

• Genitourinary: Denies blood in her urine, change in urine smell, frequency, or amount.

• Musculoskeletal: Reports weakness following episodes of nausea and vomiting.

• Neurological: Denies headache, falls, history of seizure disorder or stroke, changes in

speech, difficulty swallowing.

• Endocrine: Insulin pump stopped working about 6 months ago. Currently being managed

with injections at night and with meals.

• Psychiatric: Mood is unchanged from normal. Boyfriend states she has a history of

depression but that it is well controlled, he is not aware of any suicidal ideations past or

present.

Physical Examination

Vital signs: Heart rate 125/min, blood pressure 91/46 mm Hg, respiratory rate 25/min, and

temperature 370C, SP02 97% on BiPAP with an IPAP of 10 cm H20, and an EPAP of 5 cm H2O

with 21% FiO2.

• Constitutional: 26-year-old female on NIPPV, thin, and appearing slightly— older than

stated age.

• Head/eyes/ears/neck/throat: Pupils are equal, round, reactive to light, oral examination

deferred as the patient is on NIPPV.

• Cardiovascular: Heart rate and rhythm regular, no murmurs, rub, or gallops. No edema

noted. Nail beds are pink, cool to touch; capillary refill +3 seconds.

• Pulmonary: Lungs clear to auscultation bilaterally.

• Gastrointestinal: Hyperactive bowel sounds, tympanic on percussion, abdomen soft, but

tender in all quadrants.

• Genitourinary: Unremarkable.

• Skin: intact, no rashes, lesions, or ulcerations; skin turgor +2 seconds.

• Neurological: Unable40 fully participate due to lethargy and NIPPV mask. No focal

neurologic deficits noted, face symmetric, reflexes intact and symmetric, appropriate

blink reflex and response to painful stimuli. Able to shake head yes and no appropriately

to questions occasionally.

Case Information

Upon arrival to the MICU, vital signs were as follows: heart rate 98 beats per

minute, blood pressure 95/56 mm Hg, respiratory rate 20/min, SpO2 96% on

NIPPV room air. The NP orders another liter of normal saline bolus, and then

reviewed the medical record for more information about the patient.

Notes from her outpatient endocrinologist are in the chart. She was prescribed

glargine (Lantus) 20 units subcutaneous injection nightly and insulin lisro

(Humalog) sliding scale with meals. The notes describe the patient as being

compliant with her current regimen over the last 6 months. The notes also state

that in the past, she has struggled with using an insulin pump. The chart states

that she did not managed the injection site, did not input date into the device when

eating, and found the device “a hassle”. She dropped the device, at which time it

ceased to function. Due to these issues, she was stated on the above-described

regimen.

Her last hemoglobin A1c (HbA1c) was 7%. Further evaluation of the EMR

reveals that she was given prescriptions for captopril 50mg every 12 hours for

hypertension and fluoxetine 20mg/day for depression. No other additional

medications were prescribed. Her baseline blood pressure is 125/60 mmHg.

Diagnostic Results

ECG: normal sinus rhythm, no evidence of ischemia, no peaked T waves

Abdominal radiograph: unremarkable, no signs of bowel obstruction or free air in

the abdomen

Urinalysis: negative for leukocytes or leukesterase, positive for ketones

Laboratory Results

CBC

Result Reference Range

WBC 5,000 cells/uL 4,000–10,000 cells/uL

Differential:

%Neutrophils, bans 3% 3%-5%

%Neutrophils, segmented 70% 37%-73%

%Lymphocytes 42% 20%-40%

%Basophils 1%

%Monocytes 7% 3%-7%

%Eosinophils 1% 1%-3%

Hemoglobin 14.5 g/dL 14.4-16.6 g/dL

Hematocrit 43% 42%-49%

Platelet count 280 10/L 189-287 10/L

Metabolic Panel

Result Reference Range

Sodium 140 mEq/L 136-145 mEq/L

Potassium 5.0 mEq/L 3.5-5 mEq/L

Serum CO2 20 mEq/L 23-28 mEq/L

Chloride 105 mEq/L 98-106 mEq/L

BUN 35 mg/dL 8-20 mg/dL

Creatinine 1.7 mg/Dl 0.7-1.3 mg/dL

Magnesium 1.4 mg/dL 1.5-2.4 mg/dL

Phosphorus 5.4 mg/dL 3.0-4.5 mg/dL

Glucose 368 mg/dL Fasting 70-105 mg/dL

ABG

Result Reference Range

pH 7.25 7.35-7.45

PaCO2 25 mmHg 35-45 mmHg

PaO2 96 mmHg 80-100 mmHg

HCO3 19 mEq/L 22-26 mEq/L

Lactic acid 4 mmol/L <2 mmol/L

Case Study Questions

1. What are the pertinent positives of this case?

2. What are the pertinent negatives of this case?

3. Based on the patient's symptoms and lab results, what is your primary

diagnosis and why?

4. What are the potential reasons for the patient's elevated BUN and

creatinine levels, and how would you address these in her treatment

plan?

5. Are there any additional labs / diagnostic testing you would consider?

If so, why?