Transcript Critical / Perioperative Care

ABSITE Review Conference
Topic
Month
Head and Neck / Breast
August 09
Alimentary
Sept 09
Alimentary / Abdomen
Oct 09
Abdomen / Endocrine
Nov 09
Vascular / Pediatric Surgery
Dec 09
Surgical Physiology +
Critical Care
Jan 10
Trauma / Orthopedics
Feb 10
TBD
Mar 10
Surgical Physiology +
Critical Care /
Anesthesia
Apr 10
Oncology / Skin + Soft Tissue/
Transplant Immunology
May 10
Thoracic Surgery/ Gynecology/
Urology
June 10
Critical / Perioperative Care
A 36y M sustained a gunshot wound to the abdomen during a
robbery of his home. He sustained a right colon injury requiring a
colectomy, grade IV liver injury, and inferior vena caval injury
requiring repair. He received massive transfusion, and on admission
to the ICU had a PaO2/FiO2 ratio of 120, consistent with a diagnosis
of severe ARDS. Pulmonary artery pressures were increased at
65/32. Inhaled nitric oxide was administered. All except which of
the following have been demonstrated as beneficial effects of
inhaled nitric oxide in adult ARDS?
a.
b.
c.
d.
e.
Significant increase in PaO2
Reduced mortality in adult ARDS
Decreased pulmonary arterial pressures
Improved right ventricular function
Resolution of pulmonary hypertension
Critical / Perioperative Care
•
•
•
•
Answer b.
ALI: PaO2/FiO2 < 300
ARDS PaO2/FiO2 < 200
Both consist of acute hypoxic respiratory failure with
bilateral pulmonary infiltrates that are not attributed to left
atrial hypertension.
• Inhaled nitric oxide improves oxygenation in ALI & ARDS
but has no effect on the duration of ventilatory support or
mortality.
• Other strategies that can be tried with ARDS/ALI are
high-frequency oscillation and prone positioning.
Critical / Perioperative Care
•
A 20 y/o man fell through the ice while skating on a
lake in the middle of winter and was submerged for 10
minutes before rescue. He was intubated at the scene
and arrives in the emergency department with the first
temperature recorded at 32°C. How will cold
temperature affect the measurement of this patient’s
PaO2.
a.
b.
c.
d.
e.
No effect
10% increase in PaO2
50% increase in PaO2
10% decrease in PaO2
50% decrease in PaO2
Critical / Perioperative Care
•
A 20 y/o man fell through the ice while skating on a
lake in the middle of winter and was submerged for 10
minutes before rescue. He was intubated at the scene
and arrives in the emergency department with the first
temperature recorded at 32°C. How will cold
temperature affect the measurement of this patient’s
PaO2.
a.
b.
c.
d.
e.
No effect
10% increase in PaO2
50% increase in PaO2
10% decrease in PaO2
50% decrease in PaO2
Answer b.
Critical / Perioperative Care
Critical / Perioperative Care
•
A 42y F otherwise healthy undergoes a laparoscopic
cholecystectomy for symptomatic cholelithiasis. In the recovery
room, her temperature has increased to 43°C, heart rate is 130
beats per minute, blood pressure is 190/100, and respiratory rate
is 42 breaths per minute. She has muscular rigidity, and an ABG
on a nonrebreathing mask shows a pH of 7.1, pCO2 of 55, PO2 of
60, and an HCO3 of 16. Her lactate is 8.0. Which of the following
is false?
a.
b.
c.
d.
e.
Thus process is associated with a significant increase in oxygen
consumption
Myoplasmic calcium concentration is increased
Succinylcholine has been implicated as a cause
Inhibiting the sarcoplasmic reticulum calcium release with dantrolene
will exacerbate the disease process.
Muscle biopsy confirms the diagnosis.
Critical / Perioperative Care
• Answer d.
• The patient is demonstrating signs and symptoms consistent with
malignant hyperthermia.
• Anesthetic agents associated with malignant hyperthermia include
inhalational gasses such as halothane, enflurane, isoflurane, and
sevoflurane. Succinylcholine is also implicated.
• Onset may occur within 30 minutes or as late as 24 hours.
• The pathogenesis is thought to be abnormal function of the
sarcoplasmic calcium release channels of skeletal muscles.
• The signs and symptoms at presentation are: muscle rigidity,
increased O2 consumption, fever, hypoxia, and lactic acidosis.
• Treatment is primarily supportive. Dantrolene should also be
administered which directly inhibits the major calcium release
channel in the sarcoplasmic reticulum and has led to a decrease in
mortality of over 80%.
Critical / Perioperative Care
•
Which sample of blood will have the
lowest oxygen tension?
a.
b.
c.
d.
Coronary sinus
Femoral vein
Portal vein
Renal vein
Critical / Perioperative Care
•
Which sample of blood will have the
lowest oxygen tension?
a.
b.
c.
d.
Coronary sinus
Femoral vein
Portal vein
Renal vein
Answer a. The oxygen tension in the coronary
sinus is usually about 30%.
Critical / Perioperative Care
•
Which sample of blood will have the
highest oxygen tension?
a.
b.
c.
d.
Coronary sinus
Femoral vein
Portal vein
Renal vein
Critical / Perioperative Care
•
Which sample of blood will have the highest
oxygen tension?
a.
b.
c.
d.
Coronary sinus
Femoral vein
Portal vein
Renal vein
Answer d. The kidney receives 25% of the cardiac
output. The kidney does not require this much
oxygen and thus the renal vein has a relatively high
oxygen tension – approximately 80%.
Critical / Perioperative Care
•
IABP improvement in coronary flow is
primarily due to:
a.
b.
c.
d.
Afterload reduction
Resting the heart
Diastolic augmentation
Decreased heart rate
Critical / Perioperative Care
•
IABP improvement in coronary flow is primarily
due to:
a.
b.
c.
d.
Afterload reduction
Resting the heart
Diastolic augmentation
Decreased heart rate
Answer c. Coronary perfusion to the heart typically
occurs during diastole. This the IABP inflates
during diatole. Therefore, it should deflate on the p
wave and inflate on the T wave. It should not be
used in patients with severe aortic regurgitation.
Critical / Perioperative Care
•
Post-op day 1 after a right upper
lobectomy, your patient has a fever to
102.0. The most likely source of the
fever is:
a.
b.
c.
d.
PMN’s
Platelets
Macrophages
Lymphocytes
Critical / Perioperative Care
•
Post-op day 1 after a right upper lobectomy,
your patient has a fever to 102.0. The most
likely source of the fever is:
a.
b.
c.
d.
PMN’s
Platelets
Macrophages
Lymphocytes
Answer c. Alveolar macrophages are activated with
atelectasis and cause fever.
Critical / Perioperative Care
•
The cytokine which induces the fever in
the above patient is:
a.
b.
c.
d.
IL-1
IL-6
IL-8
IL-10
Critical / Perioperative Care
•
The cytokine which induces the fever in the
above patient is:
a.
b.
c.
d.
IL-1
IL-6
IL-8
IL-10
Answer a. IL-1 is released by the macrophages
and acts on the hypothalamus to cause fever.
Critical / Perioperative Care
•
A patient stops making urine after
surgery. All of the following values are
consistent with pre-renal failure except:
a.
b.
c.
d.
Urine Na 5
BUN/Cr ratio 35
FeNa = 0.1%
Urine osmolality 200 mOsm
Critical / Perioperative Care
• Answer d. All of the following are
consistent with pre-renal azotemia:
•
FeNa < 1%
•
Urine Na < 20
•
BUN/Cr ratio > 20
•
Urine osmolality > 500 mOsm
Critical / Perioperative Care
•
Which of the following extubation criteria
parameters is most sensitive for
predicting successful extubation:
a.
b.
c.
d.
Minute ventilation
Rapid shallow breating index
PO2 of 60 mmHg
PCO2 of 45 mmHg
Critical / Perioperative Care
•
Which of the following extubation criteria
parameters is most sensitive for predicting
successful extubation:
a.
b.
c.
d.
Minute ventilation
Rapid shallow breating index
PO2 of 60 mmHg
PCO2 of 45 mmHg
Answer b. RSBI = respiratory rate/tidal volume (L). It
should be < 100.
Critical / Perioperative Care
•
A ventilated patient has the following
ABG: pH 7.5, PCO2 55, HCO 35. This
condition is most likely caused by:
a.
b.
c.
d.
Poor minute ventilation
Aggressive NG tube suctioning
Renal failure
Severe sepsis
Critical / Perioperative Care
•
A ventilated patient has the following ABG: pH
7.5, PCO2 55, HCO 35. This condition is most
likely caused by:
a.
b.
c.
d.
Poor minute ventilation
Aggressive NG tube suctioning
Renal failure
Severe sepsis
Answer b. Metabolic alkalosis. NGT suctioning is the
most likely to cause a metabolic alkalosis.
Critical / Perioperative Care
•
A ventilated patient has the following
ABG: pH 7.5, CO2 24, HCO3 18. This
condition is most likely caused by:
a.
b.
c.
d.
Low minute ventilation
NGT suctioning
Renal failure
High minute ventilation
Critical / Perioperative Care
•
A ventilated patient has the following
ABG: pH 7.5, CO2 24, HCO3 18. This
condition is most likely caused by:
a.
b.
c.
d.
Low minute ventilation
NGT suctioning
Renal failure
High minute ventilation
Answer d. Respiratory alkalosis.
Critical / Perioperative Care
•
A critical care patient has the following
pulmonary artery catheter values:
cardiac index 1.8, SVR 3000, and wedge
pressure of 5. This is most consistent
with:
a.
b.
c.
d.
Septic shock
Hypovolemic shock
Cardiogenic shock
Neurogenic shock
Critical / Perioperative Care
• Answer b.
• Normal values
• CO: 4 – 8 L/min – but it is dependent on the size
of the patient
• CI: 2.6 – 4.2
• SVR: 1000 - 1300
• Wedge: 8 – 12
• Thus, poor cardiac index, poor filling pressures,
and a high SVR suggests hypovolemic shock.
Critical / Perioperative Care
•
A critical care patient has the following
pulmonary artery catheter values:
cardiac index 1.8, SVR 3000, and wedge
pressure of 28. This is consistent with:
a.
b.
c.
d.
Septic shock
Hypovolemic shock
Cardiogenic shock
Neurogenic shock
Critical / Perioperative Care
• Answer c. Low cardiac index, high SVR,
and high wedge pressure is most consistent
with cardiogenic shock.
CI
Septic shock
Hypovolemic
shock
Cardiogenic
shock
Neurogenic shock
SVR
Wedge
Critical / Perioperative Care
• Answer c. Low cardiac index, high SVR,
and high wedge pressure is most consistent
with cardiogenic shock.
Septic shock
Hypovolemic
shock
Cardiogenic
shock
Neurogenic shock
CI
SVR
Wedge
H
L
L
Critical / Perioperative Care
• Answer c. Low cardiac index, high SVR,
and high wedge pressure is most consistent
with cardiogenic shock.
CI
SVR
Wedge
Septic shock
H
L
L
Hypovolemic
shock
L
H
L
Cardiogenic
shock
Neurogenic shock
Critical / Perioperative Care
• Answer c. Low cardiac index, high SVR,
and high wedge pressure is most consistent
with cardiogenic shock.
CI
SVR
Wedge
Septic shock
H
L
L
Hypovolemic
shock
L
H
L
Cardiogenic
shock
L
H
H
Neurogenic shock
Critical / Perioperative Care
• Answer c. Low cardiac index, high SVR,
and high wedge pressure is most consistent
with cardiogenic shock.
CI
SVR
Wedge
Septic shock
H
L
L
Hypovolemic
shock
L
H
L
Cardiogenic
shock
L
H
H
Neurogenic shock L
L
L
Critical / Perioperative Care
•
All of the following are true of atrial
natiuretic peptide except:
a. Released from the atria when stretched
b. Causes natiuresis and diuresis
c. Is an inherent method of removing excess
volume in patients with CHF
d. Is a steroid hormone
Critical / Perioperative Care
•
All of the following are true of atrial natiuretic
peptide except:
a. Released from the atria when stretched
b. Causes natiuresis and diuresis
c. Is an inherent method of removing excess volume in
patients with CHF
d. Is a steroid hormone
Answer d. ANP is released from the atrium when
stretched. It inhibits Na absorption and water
absorption at the collecting ducts.
Critical / Perioperative Care
•
The diagnosis of abdominal
compartment syndrome is made with a
bladder pressure greater than
a.
b.
c.
d.
20mm Hg
40mm Hg
60mm Hg
80mm Hg
Critical / Perioperative Care
•
The diagnosis of abdominal compartment
syndrome is made with a bladder pressure
greater than
a.
b.
c.
d.
20mm Hg
40mm Hg
60mm Hg
80mm Hg
Answer A. Patients should be taken to the OR for a
decompressive laparotomy depending on their
clinical signs.
Critical / Perioperative Care
•
Refeeding syndrome results in al of the
following except:
a.
b.
c.
d.
Hypokalemia
Hypomagnesemia
Hyponatremia
Hypophosphatemia
Critical / Perioperative Care
• Answer c. Re-feeding syndrome can
result in hypokalemia, hypomagnesemia,
and hypophosphatemia. It occurs in
patients who are severely malnourished
and then start receiving appropriate
nutrition. The electrolyte abnormalities
can contribute to cardiac arrhythmias.
Critical / Perioperative Care
•
A respiratory quotient < 0.7 indicates:
a.
b.
c.
d.
Starvation
Overfeeding
Pure protein nutrition
Pure glucose
Critical / Perioperative Care
• Answer a. The RQ refers to the CO2
produced compared to O2 consumed.
• Carbohydrates
• Protein
• Fat
Critical / Perioperative Care
• Answer a. The RQ refers to the CO2
produced compared to O2 consumed.
• Carbohydrates
1.0
• Protein
0.8
• Fat
0.7
Critical / Perioperative Care
•
A patient in gentamicin has a peak level
of 80 and a trough of < 1. The most
appropriate management is:
a.
b.
c.
d.
Continue current dosing
Decrease dose but maintain frequency
Decrease dose and frequency
Maintain dose and decrease frequency
Critical / Perioperative Care
• Answer b. To increase the peak of the
drug, one needs to decrease the dose of
the drug. (The peak level is taken 1 hour
after dosing). To decrease the trough of a
drug, you need to increase the interval at
which the drug is given (decrease
frequency or longer time between doses).
Critical / Perioperative Care
•
Of the anesthetics listed below, which
one is most likely to cause an allergic
reaction?
a.
b.
c.
d.
Lidocaine
Bupivocaine
Mepivicaine
Procaine
Critical / Perioperative Care
• Answer d. Amide-type local anesthetics
have two i's in their names and rarely
cause allergic reactions. Ester-type local
anesthetics have one i in their name and
can cause allergic reactions because of
their PABA analogue.
Critical / Perioperative Care
•
The most predominant cell type in a 7
day old wound is:
a.
b.
c.
d.
PMNs
Macrophages
Lymphocytes
Fibroblasts
Critical / Perioperative Care
•
•
•
•
Answer d.
Day 0 – 2: PMN
Day 3 – 4: Macrophages
Day > 5: Fibroblasts
Critical / Perioperative Care
•
The most predominant type of collagen
being synthesized in a healing wound in
the 1st 24 hours is:
a.
b.
c.
d.
Type I
Type II
Type III
Type IV
Critical / Perioperative Care
• Answer c. This is eventually replaced with
Type I collagen which is present in mature
wounds and is the most predominant in
the body. Type II collagen is in articular
cartilage and Type IV collagen is present
in the basal lamina / basement membrane.
Critical / Perioperative Care
•
The maximum collagen amount in a
wound occurs at:
a.
b.
c.
d.
1 week
3 weeks
8 weeks
3 months
Critical / Perioperative Care
• Answer b. The maximum collagen
accumulation occurs at 2 – 3 weeks. After
that, the amount of collagen stays the
same but continued cross-linking improves
strength.
Critical / Perioperative Care
•
The most important cell involved in
wound healing is:
a.
b.
c.
d.
PMNs
Macrophages
Platelets
Lymphocytes
Critical / Perioperative Care
• Answer b. The most important cell type
involved in wound healing is
macrophages. Wound healing can occur
without one of the other cell types except
macrophages whose cytokine and growth
factor synthesis are instrumental to getting
the right cells to the wound for healing to
occur.
Critical / Perioperative Care
•
Steroids have been shown to slow
wound healing. The vitamin that has
been shown to prevent the negative
effect of steroids on wound healing is:
a.
b.
c.
d.
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Critical / Perioperative Care
•
Steroids have been shown to slow wound
healing. The vitamin that has been shown to
prevent the negative effect of steroids on
wound healing is:
a.
b.
c.
d.
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Answer a.
Critical / Perioperative Care
•
All of the following are true of keloids
except:
a.
b.
c.
d.
They are confined to the original scar area
Can be treated with silicone injections
Can be treated with steroids
Can be treated with XRT
Critical / Perioperative Care
• Answer a. Keloids are not confined to the
original scar (hypertrophic scar tissue is).
Keloids are treated with silicone injections,
steroids, and XRT.
Critical / Perioperative Care
•
Which of the following would be typical of
an enteral hepatic-failure formula?
a. Lower fluid volume, potassium, phosphorus,
and magnesium
b. Fifty percent reduction of carbohydrates
c. Fifty percent of proteins are in the form of
branched-chain amino acids (leucine,
isoleucine, and valine)
d. Increased arginine, omega-3 fatty acids, and
beta-carotene
Critical / Perioperative Care
• Answer C. Increasing the percentage in
branched-chain amino acids reduces the
amount of aromatic amino acids which can
cause encephalopathy in patients with
hepatic failure.
Critical / Perioperative Care
•
Nitric oxide (NO)
a.
b.
c.
d.
Is primarily made in hepatocytes
Has a half-life of 20 – 30 minutes
Is formed from the oxidation of L-arginine
Can increase thrombosis in small vessels
Critical / Perioperative Care
• Answer C. This reaction is catalyzed by
nitric oxide synthase (NOS). NO is
primarily synthesized in the endothelium
and causes vasodilation of the
vasculature.
Critical / Perioperative Care
•
The most frequent trace mineral
deficiency that develops in patients on
parenteral nutrition is:
a.
b.
c.
d.
Calcium
Chromium
Magnesium
Zinc
Critical / Perioperative Care
• Answer D.
• Zinc deficiency – eczematoid rash either
diffusely or in intertriginous areas
• Copper deficiency – microcytic anemia
• Chromium deficiency – glucose
intolerance
Critical / Perioperative Care
•
A 28y F who has been on TPN for 4
weeks develops scaling acrodermatitis
and alopecia. This condition is most
likely a result of:
a.
b.
c.
d.
Linoleic acid deficiency
Zinc deficiency
Vitamin C deficiency
Magnesium deficiency
Critical / Perioperative Care
• Answer A. Patients on prolonged TPN are
at risk of developing essential fatty acid
deficiency. Early signs of deficiency
include scaling of the skin on the digits
and shedding of hair with alopecia. There
are three types of essential fatty acids:
linoleic acid, arachadonic acid, and
linolenic acid.
Critical / Perioperative Care
•
Metabolic acidosis with a normal anion
gap occurs with:
a.
b.
c.
d.
Diabetic acidosis
Renal failure
Severe diarrhea
Starvation
Critical / Perioperative Care
• Answer C. Metabolic acidosis with a
normal anion gap results from either acid
administration or loss of bicarbonate from
the GI tract such as diarrhea, fistulas
(enteric, pancreatic, or biliary),
ureterosigmoidoscopy, or from renal loss.
The bicarbonate loss is accompanied by a
gain of chloride, thus the AG remains
unchanged.
Critical / Perioperative Care
•
The primary defect in von Willebrand’s
disease is:
a.
b.
c.
d.
Inadequate production of fibrin
Excessive fibrinolysis
Failure of platelet aggregation
Failure of vessel constriction
Critical / Perioperative Care
• Answer C. vWD is a disorder with low
factor VIII much like hemophelia A.
However, the defect in vWD is a low level
of vWF which is a carreier for factor VIII.
vWF is also responsible for platelet
adhesion to the subendothelium and
resultant aggregation.
Critical / Perioperative Care
•
Each of the following factors requires
vitamin K for its production except:
a.
b.
c.
d.
Factor VIII
Factor X
Factor IX
Factor VII
Critical / Perioperative Care
•
Each of the following factors requires vitamin K
for its production except:
a.
b.
c.
d.
Factor VIII
Factor X
Factor IX
Factor VII
–
–
Answer A.
Vitamin K dependent clotting factors: II, VII, IX, X,
and Proteins C & S.
Critical / Perioperative Care
•
Which of the following is not in the
intrinsic pathway of coagulation?
a.
b.
c.
d.
e.
II
XII
XI
IX
VII
Critical / Perioperative Care
Critical / Perioperative Care
•
A patient has a blood pressure of 70/50 mm
Hg and a serum lactate level of 30 mg/100 mL
(normal: 6 – 16). His cardiac output is 1.9
L/min, and his central venous pressure is 2 cm
H2O. The most likely diagnosis is:
a.
b.
c.
d.
Congestive heart failure
Cardiac tamponade
Hypovolemic shock
Septic shock
Critical / Perioperative Care
• Answer C. CHF and cardiac tamponade
are associated with a high CVP. Septic
shock, particularly in its early phases, is
associated with greater than normal
cardiac output.
Critical / Perioperative Care
•
Dobutamine:
a. Increases cardiac output and causes
peripheral vasodilation
b. Decreases cardiac output and causes
peripheral vasodilation
c. Increases cardiac output and causes
peripheral vasoconstriction
d. Decreases cardiac output and causes
peripheral vasoconstriction
Critical / Perioperative Care
• Answer A.
• Dobutamine: Primary stimulates β1 receptors
to increase cardiac output but also stimulates β1
receptors which dilate peripheral vascular beds.
• Dopamine:
Stimulates α receptors
(vasoconstriction), β1 receptors, and β2
receptors with its effects on β receptors
predominating at lower doses.
• Thus, dopamine is preferable to dobutamine in
treatment of cardiac dysfunction in hypotensive
patients.
Critical / Perioperative Care
•
The best method for hair removal from
an operative field is:
a.
b.
c.
d.
Razor the night before
Razor the week before
Razor in the operating room
Hair clippers in the operating room
Critical / Perioperative Care
•
The best method for hair removal from
an operative field is:
a.
b.
c.
d.
Razor the night before
Razor the week before
Razor in the operating room
Hair clippers in the operating room
Answer D. Hair removal should take place
using a clipper rather than a razor.
Critical / Perioperative Care
•
Which of the following values indicates an
adult with a significant risk for pulmonary
problems after an abdominal operation?
a. Forced expiratory volume in 1 second (FEV1) 2.5 L
b. Forced vital capacity (FVC) 80% of predicted value
c. Maximum breathing capacity (MBC) 70% of
predicted value
d. PaCO2 50 mm Hg
Critical / Perioperative Care
•
•
•
•
•
Answer D.
Acceptable pulmonary function tests:
PaCO2 < 45
FEV1 > 2 L
FVC > 70 – 80% predicted value
Critical / Perioperative Care
•
Which of the following conditions is/are
usually associated with elevated dead
space ventilation?
a.
b.
c.
d.
e.
Low CO
Pulmonary embolism
Pulmonary hypertension
ARDS
All of the above
Critical / Perioperative Care
•
Which of the following conditions is/are usually
associated with elevated dead space
ventilation?
a.
b.
c.
d.
e.
Low CO
Pulmonary embolism
Pulmonary hypertension
ARDS
All of the above
Answer E. Increased dead space ventilation is
associated with a decrease in the end tidal CO2.
This scenario has been on past ABSITE exams.
Critical / Perioperative Care
•
A 50y M trauma patient is admitted to the ICU with a GCS of 8,
unilateral posturing, and a systolic blood pressure of 70 mm Hg.
Accepted treatment of thus patient includes which of the
following?
a.
e.
Fluid resuscitation to reach a cerebral perfusion pressure of 70
mmHg or above.
Mild hyperventilation to a PaCO2 of 35 mm Hg
Transient moderate hypothermia
Cerebrospinal fluid drainage for persistent elevated intracranial
pressure
d
f.
All of the above
b.
c.
d.
Critical / Perioperative Care
• Answer f. As a rule of thumb a
ventriculostomy catheter should be placed
for a GCS < 8.
Critical / Perioperative Care
•
What controls local coronary artery
vasodilation?
a.
b.
c.
d.
Acetylcholine
Adenosine
Prostaglandin E2
Thromboxane
Critical / Perioperative Care
• Answer D. Adenosine is an important
mediator of active hyperemia and
autoregulation. It serves as a metabolic
coupler between oxygen consumption and
coronary blood flow. Nitric oxide is also an
important regulator of coronary blood flow.
Critical / Perioperative Care
•
A 25y F presents with persistent headaches
and polyuria. You draw serum and urine labs
and they come back as the following: Serum
osmolarity: 310, urine osmolarity 250, serum
sodium 150. These are most consistent with:
a.
b.
c.
d.
SIADH
Diabetes insipidus
Fluid volume deficit
Fluid volume excess
Critical / Perioperative Care
• Answer b. Diabetes insipidus can be
either central or nephrogenic. Central is
characterized by decreased secretion of
ADH and can be treated with
desmopressin. In contrast, nephrogenic
diabetes insipidus is characterized ADH
resistance in the kidney and is usually
treated with nonhormonal drugs.
Critical / Perioperative Care
Serum Osmolality
Urine Osmolality
Clinical Significance
Normal: 282 – 295 mOsm
Normal: 500 – 800 mOsm
Normal  Increased
Increased
Fluid volume deficit
Decreased
Decreased
Fluid volume excess
Normal
Decreased
Increased fluid intake or diuretics
Normal  Increased
Decreased (with no increase with
fluid intake)
Kidneys unable to concentrate
urine OR Diabetes Insipidus
Decreased
Increased
SIADH
Critical / Perioperative Care
•
A 5y F comes to the ER after being bit by
a cat three days ago. The area is
erythematous and the mother says that
she has been having fevers. What is the
most likely source of the infection?
a.
b.
c.
d.
Pasturella
Staphylococcus Aureus
Bartonella
Brucella
Critical / Perioperative Care
• Answer A. There is also some Staph in
the canine mouth. Bartonella is
associated with cat scratch fever. Brucella
is responsible for “Mediterranean Fever.”
Critical / Perioperative Care
•
Which of the following is most consistent
with a diagnosis of COPD
(emphysema)?
a.
b.
c.
d.
Increased FEV1
Decreased TLC
Decreased RV
Decreased FEV1/FVC ratio
Critical / Perioperative Care
• Answer d. An FEV1/FVC ratio 0.70 is
consistent with a diagnosis of COPD. This
ratio also decreased with age and can
thus lead to a false diagnosis of COPD in
some elderly patients.
Critical / Perioperative Care
Critical / Perioperative Care
•
A 56y M post liver transplant patient
undergoes a ventral hernia repair. On the
night following surgery he develops abdominal
pain and low urine output. You bolus him with
normal saline and he does not respond. You
check his HCT and it is normal. His blood
pressure starts to fall. What is the next most
important step in his management?
a.
b.
c.
d.
Additional fluid
Start a pressor
Give him steroids (gluco+mineralocorticoid)
Flush the foley catheter
Critical / Perioperative Care
• Answer c. This is the typical presentation
of a patient with adrenal insufficiency:
• GI: nausea, vomiting, abd pain, diarrhea
• psych: apathetic affect
• electrolytes: hypoNa, hyperK, hypoCl,
hypoglycemia
• acid/base: metabolic acidosis
Critical / Perioperative Care
•
Which of the following statements are
true? Milrinone:
a.
b.
c.
d.
Is a cAMP phosphodiesterase inhibitor
Is An inotrope
Causes decreased SVR and PVR
Causes less thrombocytopenia than
amrinone
e. A and B
f. All of the above
Critical / Perioperative Care
•
Which of the following statements are true?
Milrinone:
a.
b.
c.
d.
e.
f.
Is a cAMP phosphodiesterase inhibitor
Is An inotrope
Causes decreased SVR and PVR
Causes less thrombocytopenia than amrinone
A and B
All of the above
Answer F. All of the statements are true.
Critical / Perioperative Care
•
Isoproterenol:
a.
b.
c.
d.
Activates β1 and β2 receptors equally
Activates β1 receptors only
Activates β2 receptors only
Activates α1 and α2 receptors
Critical / Perioperative Care
•
Isoproterenol:
a.
b.
c.
d.
Activates β1 and β2 receptors equally
Activates β1 receptors only
Activates β2 receptors only
Activates α1 and α2 receptors
Answer a. It’s primary use is for bradycardia or heart
block. It can cause tachycardia which predisposes
to cardiac dysrhythmias. It should not be given to
patients with myocardial ischemia.
Critical / Perioperative Care
Critical / Perioperative Care
•
Which of the following is true re: first
order pharmacokinetics?
a. Rate of elimination is variable
b. Can occur in overdose situations where
clearance processes are saturated
c. Half-life does not vary with the dose
d. All of the above
Critical / Perioperative Care
• Answer C.
• First-order kinetics:
• A constant fraction of the drug is removed during a
period of time.
• The absolute amount of drug removed is
proportional to the concentration of drug
• It takes approximately 5 half-lives for a drug with
first-order kinetics to be completely (almost)
eliminated.
• In zero-order kinetics a constant amount of the
drug is removed regardless of the concentration.
Critical / Perioperative Care
GOOD LUCK!