Critical care Flashcards
1
Q
- A 58-year-old woman remains intubated in the
intensive care unit (ICU) after a recent abdominal
operation. In the operating room, she receives
more than 10 L of fluid and blood products, but has
received aggressive diuresis with furosemide postoperatively.
In the past 3 days, she has generated
12 L of urine output, and her blood urea nitrogen
(BUN) and serum creatinine (SCr) have steadily
increased to 40 and 1.5 mg/dL, respectively. Her
urine chloride (Cl) concentration was 9 mEq/L
(24 hours after her last dose of furosemide). This
morning, her arterial blood gas (ABG) reveals pH
7.50, Paco2 46 mm Hg, and bicarbonate (HCO3
−)
34 mEq/L. Her vital signs include blood pressure
85/40 mm Hg and heart rate 110 beats/minute.
Which action is best to improve her acid-base status?
A. 0.9% sodium chloride bolus.
B. 5% dextrose (D5W) bolus.
C. Hydrochloric acid infusion.
D. Acetazolamide intravenously.
A
- Answer: A
Hydrochloric acid infusions are rarely used in practice
and are typically reserved for more severe alkalosis
(pH greater than 7.55) that is not responding to conventional
therapy (Answer C is incorrect). Administering
D5W will provide hydration but will not correct intravascular
volume depletion (Answer B is incorrect).
Acetazolamide (Answer D) would be a consideration
if the metabolic alkalosis persisted after correcting
the underlying problem (i.e., volume contraction).
This patient’s ABG and urine Cl are consistent with a
saline-responsive metabolic alkalosis. In critically ill
patients, the most common cause of metabolic alkalosis
is volume contraction. In this case, the volume contraction
is probably caused by overly aggressive diuresis.
In patients receiving diuretics, the urine Cl should be
measured at least 12–24 hours after the last dose. In
addition, the patient is hypotensive with an elevated
heart rate, which probably represents hypovolemia.
This patient should receive a normal saline infusion
(Answer A is correct).
2
Q
- A 21-year-old man (weight 80 kg) admitted 1
day ago after a gunshot wound to the abdomen
is receiving mechanical ventilation and is thrashing
around in bed and pulling at his endotracheal
tube. His score is +3 on the Richmond Agitation-
Sedation Scale (RASS). The patient is negative for
delirium according to the Confusion Assessment
Method for the ICU (CAM-ICU). His pulmonary
status precludes extubation, and the attending physician
estimates that he will remain intubated for at
least 48 more hours. The medical team has decided
that his RASS goal should be between 0 and -1.
He is receiving a fentanyl infusion (150 mcg/hour),
which has been adequately controlling his pain
(Critical-Care Pain Observation Tool [CPOT] less
than 3 for 24 hours). Vital signs include blood pressure
110/70 mm Hg and heart rate 110 beats/minute.
His baseline QTc interval is 460 milliseconds.
Which is the best intervention for achieving this
patient’s RASS goal?
A. Initiate a dexmedetomidine 1-mcg/kg loading
dose over 10 minutes, followed by 0.2 mcg/kg/
hour.
B. Initiate a lorazepam 3-mg intravenous load,
followed by a lorazepam 3-mg/hour infusion.
C. Initiate propofol at 5 mcg/kg/minute and
titrate by 5 mcg/kg/minute every 5 minutes as
needed.
D. Initiate haloperidol 1 mg intravenously, and
double the dose every 20 minutes as needed.
A
- Answer: C
If analgesia with fentanyl is adequate, this patient needs
a sedative to achieve his RASS goal. Propofol is a sedative
that is easily titrated and cost-effective (Answer C is
correct). Dexmedetomidine is another safe and effective
option, even when used for longer than 24 hours, but it
has not been shown superior to propofol in randomized
controlled trials (Answer A is incorrect). Furthermore,
dexmedetomidine is more expensive than propofol, and
a loading dose is not recommended. Lorazepam should
be avoided in patients with (or at high risk of) delirium
and is not a preferred first-line agent in the guidelines
(Answer B is incorrect). Haloperidol is incorrect
because the patient is CAM-ICU negative (Answer D is
incorrect). Haloperidol can cause further prolongation
of the QTc interval and lead to torsades.
3
Q
- A 62-year-old woman is admitted to the medical
ICU for respiratory dysfunction necessitating
mechanical ventilation. She has no significant
medical history. Her chest radiograph reveals
bilateral lower lobe infiltrates, her white blood cell
count (WBC) is 21 × 103 cells/mm3, lactate is 1.7
mmol/L, temperature is 103.3°F (39.6°C), blood
pressure is 82/45 mm Hg (normal for her is 115/70
mm Hg), heart rate is 110 beats/minute, and respiratory
rate is 22 breaths/minute. After she is given
a diagnosis of community-acquired pneumonia,
she is empirically initiated on ceftriaxone 2 g/day
and azithromycin 500 mg/day intravenously. After
fluid resuscitation with 6 L of lactated Ringer solution,
her blood pressure is unchanged. Dopamine
is initiated and titrated to 9 mcg/kg/minute, with a
resulting blood pressure of 96/58 mm Hg, and her heart rate is 138 beats/minute. She has made less
than 100 mL of urine during the past 6 hours, and
her SCr has increased from 0.9 mg/dL to 1.3 mg/
dL. Her serum albumin concentration is 2.7 g/dL.
Which therapy is best for this patient at this time?
A. Administer 5% albumin 500 mL intravenously
over 1 hour and reassess mean arterial
pressure (MAP).
B. Initiate hydrocortisone 50 mg intravenously
every 6 hours.
C. Change dopamine to norepinephrine 0.01
mcg/kg/minute to maintain a MAP greater
than 65 mm Hg.
D. Reduce the dopamine infusion to 1 mcg/kg/
minute to maintain a urine output of at least 1
mL/kg/hour.
A
- Answer: C
This patient meets the definition for septic shock.
Treatment with 5% albumin is unlikely to offer additional
benefit because the patient’s MAP is at goal (more
than 65 mm Hg) (Answer A is incorrect). Furthermore,
colloids are no more effective than crystalloids for fluid
resuscitation, and a serum albumin concentration does
not predict the efficacy of albumin administration.Hydrocortisone is incorrect because the patient is not
persistently hypotensive after receiving fluids and
vasopressors (Answer B is incorrect). Although this
patient’s blood pressure is responding to the infusion of
dopamine, the heart rate has increased. Norepinephrine
(Answer C) is correct because it has similar efficacy,
but with fewer tachyarrhythmias than dopamine.
Dopamine should not be reduced because lower doses
are not renal protective (Answer D is incorrect).
4
Q
- A 92-year-old woman (weight 51 kg) is admitted
to the ICU with urosepsis and septic shock. She
lives in a long-term care facility and has a medical
history significant for coronary artery disease
and hypertension. Her blood pressure is 72/44 mm
Hg, central venous pressure (CVP) is 5 mm Hg,
heart rate 120 beats/minute, and oxygen saturation
(Sao2) is 99%; her laboratory values are normal,
except for a BUN of 74 mg/dL and Cr of 2.7 mg/dL
(baseline of 1.5 mg/dL). Her urine output is about
20 mL/hour. Appropriate empiric antibiotics were
initiated. Which therapy is most appropriate to initiate
next?
A. Norepinephrine 0.05 mcg/kg/minute.
B. Lactated Ringer solution 1500-mL bolus.
C. Dopamine 5 mcg/kg/minute.
D. Albumin 5% 500-mL bolus.
A
- Answer: B
The SSC guidelines recommend adequate fluid resuscitation
with either crystalloids or colloids before adding
vasopressor agents in patients with sepsis. This
patient’s CVP, blood pressure, heart rate, and BUN/
creatinine ratio indicate that she has intravascular
volume depletion and needs immediate volume
replacement. Therefore, intravenous fluids with either
crystalloid or colloid should be the next therapy added
to this patient’s regimen. Answers A and C are incorrect
because fluid resuscitation should be attempted
before adding vasopressors. No data favor colloids over
crystalloids, and the substantial increase in cost associated
with colloids precludes it from being first line;
therefore, Answer D (albumin) is incorrect. Lactated
Ringer solution is cost-effective and is a first-line agent
per current guidelines (Answer B is correct).
5
Q
- A 46-year-old man had a witnessed cardiac arrest
in an airport terminal. After about 5 minutes, emergency
medical services arrived, and defibrillator
pads were applied. The cardiac monitor showed
ventricular tachycardia (VT), and the patient had
no discernible pulse. He was defibrillated with
200 J without return of spontaneous circulation
(ROSC). He received an additional two shocks of
200 J with no improvement. Between shocks, the
patient received compressions. An intravenous line
was obtained, and an epinephrine 1-mg intravenous
push was given; chest compressions and artificial respirations were initiated. Within 1 minute, the
patient was reassessed. The cardiac monitor still
showed VT, and he remained pulseless; therefore,
another shock of 200 J, followed by an amiodarone
300-mg intravenous push, was administered. After
this, the patient was converted to a normal sinus
rhythm with a heart rate of 100 beats/minute. The
patient was then transported to the hospital, intubated
and unresponsive. Which recommendation is
most likely to improve this patient’s outcomes?
A. Administer sodium bicarbonate 50 mEq
intravenously.
B. Administer vasopressin 40 units intravenously.
C. Administer a continuous infusion of heparin.
D. Initiate a targeted temperature management
protocol.
A
- Answer: D
Targeted temperature management (i.e., therapeutic
hypothermia) improves neurologic recovery and mortality
in patients who have had a cardiac arrest (Answer
D is correct). Although the patient probably has a metabolic
acidosis, administering sodium bicarbonate
would not improve outcomes (Answer A is incorrect).
Vasopressin is no longer recommended in the ACLS
guidelines (Answer B is incorrect). Although acute coronary
syndrome is a common cause of cardiac arrest,
anticoagulation with heparin would be a consideration
after initiating targeted temperature management. A
continuous infusion of heparin does not improve mortality
in patients with an acute coronary syndrome
(Answer C is incorrect). Of note, the induction of hypothermia
would not necessarily interfere with treatment
plans for acute coronary syndrome (e.g., percutaneous
coronary intervention).
6
Q
- A 72-year-old man is admitted to the medical ICU
for post-cardiac arrest care with therapeutic hypothermia.
His body temperature was maintained
at 91.4°F (33°C) for 24 hours, and the health care
team decides it is time to rewarm slowly at 0.5°C
every hour. Which is most important to consider
during the rewarming phase?
A. Frequent laboratory monitoring is necessary
to guide potassium supplementation because
of the risk of hypokalemia.
B. A vecuronium continuous infusion should be
administered to prevent shivering.
C. Phenytoin should be administered for seizure
prophylaxis.
D. Frequent blood glucose monitoring is necessary,
given the risk of hypoglycemia.
A
- Answer: D
The cooling phase of therapeutic hypothermia may
cause an intracellular shift of potassium, leading to
decreased serum potassium on laboratory results.
During the rewarming phase, an extracellular shift
occurs, placing the patient at risk of hyperkalemia
(Answer A is incorrect). Paralytics are not mandatory
for shivering prevention during the rewarming phase
and should be avoided, if possible (Answer B is incorrect).
The rewarming phase of targeted temperature
management alone does not place the patient at an
increased risk of seizures, so prophylaxis with phenytoin
is not required (Answer C is incorrect). Answer D,
frequent blood glucose monitoring, is correct.
7
Q
7.A 65-year-old man with a history of hypothyroidism,
heart failure, and myocardial infarction is
admitted to the ICU with severe community-acquired
pneumonia. Six hours after admission, he
develops acute respiratory failure, hypotension,
and acute kidney injury from presumed sepsis. He
is placed on mechanical ventilation, and a nasogastric
tube is placed, with no plans for extubation.
Which is most appropriate for this patient’s stress
ulcer prophylaxis (SUP)?
A. Administer sucralfate 1 g four times daily by
nasogastric tube.
B. Administer magnesium hydroxide 30 mL four
times daily by nasogastric tube.
C. Administer famotidine 20 mg intravenously
daily.
D. No prophylaxis is indicated for this patient
because he has no risk factors for SUP.
A
- Answer: C
Mechanical ventilation for more than 48 hours is an
independent risk factor for stress ulcers; therefore,
Answer D is incorrect because the patient has a high
risk of developing a stress ulcer and should receive
prophylaxis. Antacids such as magnesium hydroxide
are not used to prevent stress ulcers because of their
need for frequent dosing and increased adverse effects
(Answer B is incorrect). Sucralfate was inferior to H2
receptor blockers in preventing clinically significant
bleeding (Answer A is incorrect). Histamine-2 receptor
blockers and PPIs are the two drug classes commonly
used to prevent stress ulcers in critically ill patients
(Answer C is correct).
8
Q
- A 45-year-old man is admitted to the ICU with
H1N1 causing respiratory failure. He is intubated
and sedated with fentanyl 200 mcg/hour and
propofol 25 mcg/kg/minute. He has received 4 L
of lactated Ringer solution and 1 L of albumin and
is currently receiving norepinephrine 0.15 mcg/kg/
minute and vasopressin 0.03 unit/minute for hemodynamic
support. His current vital signs are blood
pressure 85/58 mm Hg, heart rate 99 beats/minute,
and respiratory rate 18 breaths/minute. Which is
the best plan for this patient’s steroid therapy?
A. Initiate hydrocortisone 50 mg every 6 hours
intravenously.
B. Perform a cosyntropin stimulation test and
initiate hydrocortisone 50 mg every 6 hours
intravenously if the patient does not have an
increase greater than 9 mcg/dL from baseline.
C. Check a random cortisol and initiate
hydrocortisone
50 mg every 6 hours intravenously
if the result is less than 10 mcg/dL.
D. Steroids are not indicated at this time.
A
- Answer: A
The SSC suggests hydrocortisone at a dose of 200 mg
per day if fluids and vasopressors cannot restore hemodynamic
stability (Answer A is correct; Answer D is
incorrect). Although low, random cortisol concentrations
predict worse outcomes, there are no data supporting
treatment of low cortisol concentrations (Answer C
is incorrect). Because of the results of the most recent
clinical trial and increased health care costs, a cosyntropin
stimulation test is not recommended for patients
with septic shock (Answer B is incorrect).
9
Q
- A 19-year-old man (height 71 inches [180 cm],
weight 68 kg) is admitted to the ICU after ingesting
an unknown quantity of acetaminophen. After initial
resuscitation and treatment with acetylcysteine,
the patient remains unresponsive and intubated.
The intensivist would like to start enteral nutrition
(EN) as soon as possible. Which is the best way to
calculate the patient’s caloric and protein needs?
A. Estimate caloric needs at 25 kcal/kg and protein
at 1.2 g/kg.
B. Perform indirect calorimetry to estimate
caloric and protein needs.
C. Estimate caloric needs at 14 kcal/kg and protein
at 2 g/kg.
D. Calculate caloric needs based on the Mifflin
equation, and order a prealbumin concentration
to assess protein needs.
A
- Answer: A
There are many ways to estimate nutritional needs in
critically ill patients. In general, 25 kcal/kg is an appropriate
goal caloric intake per day. The recommended
protein intake for medically ill patients in the ICU is
1.2-1.5 g/kg (Answer A is correct). Indirect calorimetry
will most closely calculate caloric needs, but it does not provide information on the amount of protein needed
(Answer B is incorrect). Feeding at 11–14 kcal/kg is recommended
for patients with obesity, but this patient’s
BMI is less than 30 kg/m2 (Answer C is incorrect).
Prealbumin concentrations have not shown good correlation
with nutritional deficits in critically ill patients
and are not recommended (Answer D is incorrect).
10
Q
- A 57-year-old woman is admitted to the ICU with
injuries sustained after a fall from 12 feet. She has
traumatic brain injury and has been intubated for
airway protection. What is the best intervention
to prevent ventilator-associated pneumonia in this
patient?
A. Initiate pantoprazole 40 mg intravenously daily.
B. Perform selective digestive decontamination
with enteral polymyxin B sulfate, neomycin
sulfate, and vancomycin hydrochloride.
C. Maintain head of bed elevation at 20 degrees
at all times.
D. Start chlorhexidine 0.12% oral swabs twice
daily.
A
- Answer: D
Proton pump inhibitors have been associated with
an increase in ventilator-associated pneumonia
(Answer A is incorrect). Selective digestive decontamination
is effective, but because of its adverse
effects and increases in resistant bacteria, it is not
in widespread use and is not part of the Institute for
Healthcare Improvement ventilator bundle (Answer
B is incorrect). Head elevation prevents ventilatorassociated
pneumonia, but it should be 30–45 degrees
(Answer C is incorrect). Chlorhexidine is inexpensive,
carries few adverse effects, is easy to administer, and
is effective in the prevention of ventilator-associated
pneumonia (Answer D).
11
Q
- You are the critical care pharmacist for a 300-bed
hospital. The critical care committee wants to
institute an evidence-based glucose control protocol
for the ICU. What is the best goal to implement
for patients who present with septic shock?
A. Check blood glucose every 6 hours and treat
with sliding scale protocol when greater than
180 mg/dL.
B. Initiate insulin infusion with a target of
110–140 mg/dL for two blood glucose values
greater than 140 mg/dL.
C. Initiate insulin infusion with a target of
110–180 mg/dL for two blood glucose values
greater than 180 mg/dL.
D. Initiate insulin infusion with a target blood
glucose of 80–110 mg/dL for two blood glucose
values greater than 150 mg/dL.
A
- Answer: C
A sliding-scale protocol is inappropriate as the sole
therapy for hyperglycemia in the ICU (Answer A is
incorrect). The SSC and SCCM guidelines recommend
an insulin infusion for two blood glucose values
greater than 180 mg/dL (Answer B is incorrect). The
ideal blood glucose range for critically ill adults has yet
to be determined, but a goal of 80–110 mg/dL will not
improve outcomes and may increase mortality (Answer
D is incorrect). A target of 110–180 mg/dL prevents
hyperglycemia but without an excess risk of hypoglycemia
(Answer C is correct).
12
Q
- Which is the most appropriate therapy to reduce
the risk of delayed ischemia and improve neurologic
outcomes after an aneurysmal subarachnoid
hemorrhage (SAH)?
A. Clevidipine continuous infusion titrated to
maintain a systolic blood pressure (SBP) less
than 160 mm Hg.
B. Nimodipine 60 mg orally every 4 hours for 21
days.
C. Norepinephrine continuous infusion titrated
to maintain an SBP greater than 160 mm Hg.
D. Amlodipine 10 mg orally every 24 hours for 21
days.
A
- Answer: B
Nimodipine should be administered in all patients with
an aneurysmal SAH for 21 days to reduce the risk of
delayed cerebral ischemia and improve neurologic outcomes
(Answer B is correct). Blood pressure control
is important, and the guidelines recommend using a
titratable agent such as clevidipine to maintain a goal
systolic blood pressure less than 160 mm Hg (Answer
C is incorrect). The value of calcium antagonists other
than nimodipine for vasospasm remains uncertain
(Answers A and D are incorrect).
13
Q
Patient Cases
1. A 62-year-old woman has been hospitalized in the ICU for several weeks. Her hospital stay has been complicated
by aspiration pneumonia and sepsis, necessitating prolonged courses of antibiotics. For the past few
days, she has been having high temperatures, and her stool output has increased dramatically. Her most recent
stool samples have tested positive for Clostridioides difficile toxin, and her laboratory tests show serum sodium
138 mEq/L, K 3.5 mEq/L, Cl 115 mEq/L, HCO3
− 15 mEq/L, albumin 4.4 g/dL, pH 7.32, and Paco2 30 mm Hg.
Which is most consistent with this patient’s primary acid-base disturbance?
A. AG metabolic acidosis.
B. Non-AG metabolic acidosis.
C. Chloride-responsive metabolic alkalosis.
D. Acute respiratory acidosis.
A
- Answer: B
This patient’s ABG is consistent with metabolic acidosis.
The pH is less than 7.40, indicating primary acidosis
(Answer C is incorrect). The HCO3
− and Paco2 are
lower than normal, indicating this is metabolic in origin
(Answer D is incorrect). In metabolic acidosis, the
decrease in HCO3
− is the primary disorder. When metabolic
acidosis is present, the AG should be calculated
to provide additional insight about the potential cause
of the disorder. The AG is calculated by subtracting the
sum of measured anions (Cl− and HCO3
−) from cations
(Na+). This patient’s AG (8 mEq/L) is within the normal
reference range of 6–12 mEq/L; therefore, it is called
a normal AG metabolic acidosis or non-AG metabolic
acidosis (Answer B is correct; Answer A is incorrect).
C. difficile–induced diarrhea is the most likely cause of
this patient’s acid-base disorder.
14
Q
- A 32-year-old man with no pertinent medical history is admitted to the hospital after being “found down” in
his home with an empty bottle of alprazolam by his side. On arrival at the emergency department, he was neurologically
unresponsive, with the following ABG values: pH 7.21, Paco2 58 mm Hg, Pao2 90 mm Hg, HCO3−
24 mEq/L, and Sao2 86% on 2 L/minute of oxygen by nasal cannula. Which action is most appropriate?
A. Administer acetazolamide 500 mg intravenous push.
B. Administer 100% oxygen by face mask.
C. Give sodium bicarbonate 100 mEq intravenous push.
D. Provide urgent intubation.
A
- Answer: D
In patients without chronic obstructive pulmonary
disease, a Paco2 greater than 50 mm Hg is usually an
indication for mechanical ventilation, regardless of
oxygenation status. Oxygen therapy alone is unlikely
to correct this patient’s cause of respiratory failure
(hypoventilation) (Answer B is incorrect). Similarly,
his acid-base disturbance is consistent with a pure acute
respiratory acidosis (elevated Paco2, normal HCO3-)
and is therefore unlikely to respond to HCO3- (Answer
C is incorrect). Acetazolamide is used for metabolic
alkalosis (Answer A is incorrect). Given this patient’s
neurologic status and elevated Paco2, he should be intubated
and transferred to the ICU (Answer D is correct).
15
Q
- A 55-year-old woman is admitted to the hospital after several days of worsening shortness of breath. Recently,
she was discharged from the hospital after a similar episode and was doing fine until 3 days before admission,
when she developed a productive cough, necessitating an increase in her home oxygen and more frequent use
of her metered dose inhalers. On admission to the medical ICU, she was anxious and markedly distressed, with
rapid, shallow breaths. She was hypertensive (160/80 mm Hg), tachycardic (140 beats/minute), and tachypneic
(respiratory rate 28 breaths/minute). Her ABG showed pH 7.30, Paco2 59 mm Hg, Pao2 50 mm Hg, HCO3− 28
mEq/L, and Sao2 83% on 6 L/minute of oxygen by face mask, and she was immediately intubated. Her most
recent laboratory tests show serum sodium 142 mEq/L, K 3.8 mEq/L, Cl 109 mEq/L, HCO3− 28 mEq/L, and
albumin 4.1 g/dL. Which primary acid-base disturbance is most consistent with this patient’s presentation and
laboratory data?
A. AG metabolic acidosis.
B. Non-AG metabolic acidosis
C. Respiratory acidosis.
D. Respiratory alkalosis.
A
- Answer: C
This patient’s ABG is consistent with respiratory acidosis.
The pH is below 7.40, indicating acidosis (Answer
D is incorrect). The Paco2 is higher than normal (about
40 mm Hg). In chronic respiratory acidosis, the kidneys
conserve HCO3- (a base) to maintain a normal pH. This
patient’s compensatory metabolic alkalosis is obvious,
given that her serum HCO3- is 28 mEq/L (which
is about 4 mEq/L higher than normal). This patient’s
elevated HCO- concentration confirms the diagnosis
of
respiratory acidosis (because the HCO3- would be less
than 24 mEq/L if the acidemia were attributable to a
metabolic cause) (Answer C is correct; Answers A and
B are incorrect).
