c3. BASIC PRInciples A (1-75) Flashcards
- If a patient is on MAO therapy, which is the vasopressor of choice>
a. mephentermine
b. phenylephrine
c. ephedrine
d. metaraminol
-b. direct acting vasopressors should be used in MAO therapy. Phenylephrine is the only direct-acting drug of the listed choices.
- A solution containing a 1:200,000 concentration equals:
a. 0.5 mcg/mL
b. 1 mcg/mL
c. 5 mcg/mL
d. 50 mcg/mL
c. 5 mcg/mL
Based on a system of grams per liter, a 1: 200,000 concentration is equal to 5 mcg/mL
- What premedication might be important in the diabetic patient which peripheral neuropathy.
a. sodium citrate to increase gastric pH
b. metoclopramide to increase gastric emptying
c. glycopyrrolate to decrease oral secretions
d. cimetidine for H2 receptor antagonism
-b. metoclopramide (reglan) to increase gastric emptying
Diabetic patients often have gastric atony; thus, a gastrokinetic agent such as reglan may be useful to ensure an empty stomach
- Which of the following would be a possible indication of a venous air embolism?
a. increased ETco2
b. decrease ETco2
c. increased arterial blood pressure
d. decreased pulmonary artery pressure
-b. decreased ETco2
Venous air embolism, such as seen in sitting procedures, may be detected by a reduced end expired CO2, resulting from the ventilation/perfusion mismatch.
- Which of the following IV solutions is best avoided in the neurosurgical patient?
a. balanced salt solution
b. dextrose and water
c. normal saline
d. lactated ringer’s solution
-b. dextrose and water
Glucose containing solutions are avoided in all neurosurgical patients because they can exacerbate ischemic damage and cerebral edema (glucose is hypertonic and will draw water to the site)
- One of the quickest ways to decrease intracranial pressure in the acute situation is:
a. cerebrospinal fluid drainage
b. corticosteroid administration
c. hyperventilation
d. loop diuretics
-c. hyperventilation reduces brain volume by decreasing cerebral blood flow through cerebral vasoconstriction. For every millimeter of mercury change, cerebral blood flow decreases by approximately 4%.
- In the patient with increased intracranial pressure, what should the ideal PaCO2 level be?
a. 30-35 mmHg
b. 22-29 mmHg
c. 25-30 mmHg
d. 35-40 mmHg
-c. Hyperventilation to tge PaCO2 of 25 to 30 mmHg is the mainstay of acute and subacute treatment for intracranial hypertension.
- Which inhalation agent increases pulmonary vascular resistance?
a. halothane
b. enflurane
c. nitrous oxide
d. isoflurane
-c. nitrous oxide
Most inhalation anesthetics in the absence of a pathologic process have little effect on or decrease pulmonary vascular resistance. Nitrous oxide may increase resistance, especially in patients with pulmonary hypertension.
- The operation of what monitoring device uses Lambert-Beer law?
a. pulse oximetry
b. ETCO2 monitoring
c. pneumatic blood pressure cuff
d. mass spectrometry
-a. pulse oximetry
The lambert beer law relates to the observation that oxygenated and reduced hemoglobin differ in their absorption of red and infrared light. Pulse oximetry monitoring is based on this principle.
- How do you calculate cardiac output?
a. CO = SVR x PVR
b. CO = SV x HR
c. CO = HR x SVR/2
d. CO = SV x PVR
-b. SV x HR
Cardiac output is equal to stroke volume times heart rate and is expressed in “liters/minute”. The normal range is 4 to 8
- How do you calculate cardiac index?
a. CI = SV x PVR
b. CI =CO x BSA
c. CI =CO/BSA
d. CI =NAP - CVP X BSA
-c. CI = CO/BSA
Cardiac Index is derived from the cardiac output divided by the body surface area and is expressed as “liters/minute/meters squared”. normal range is 2.5 to 4
- What is the normal value of a cardiac index?
a. 2.4-4.2 L/min
b. 5-6 L/min
c. 2-3 L/min
d. 5-6 L/min
-a. 2.5-4.2 L/min
cardiac output is derived from the cardiac output divided by body surface area and is expressed as liters per minute per meter squared
- How do you calculate systemic vascular resistance?
a. SVR = PVR X SV
b. SVR = (MAP-CVP) X 80/CO
c. SVR = MAP-CO/80
d. cannot determine
-b SVR = (MAP-CVP) X 80/CO or (MAP-CVP /CO X 80
Systemic vascular resistance is calculated from this formula
- What is the normal value for SVR?
a. 100-200 L/min
b. 900-1000 L/min/m2
c. 5-6 dynes/sec/cm-5
d. 1200-1500 dynes/sec/cm-5
-d. 1200-1500 dynes/sec/cm-5
that is the normal SVR
- All of the following are complications of central venous catheters except:
a. erratic and inacurate readings
b. infection
c. venous air embolism
d. catheter shearing
-a. erratic and inacurate readings
When proprely functioning venous catheters rarely give erratic and inacurate readings; however, the other complications are always possible
- Which vessel is at greatest risk of accidental puncture if a left internal jugular approach is used to place a central venous line?
a. subclavian vein
b. external jugular vein
c. carotid artery
d. subclavian artery
-c. carotid artery
Puncture of the carotid artery is especially prominent in left internal jugular cannulation. Using the right internal jugular is safer, with less likelihood of arterial puncture.
- One way to decrease the risk of venous air embolism during central line placement might include:
a. have the patient hold his or her breath during the procedure
b. administer vasopressors to increase blood pressure
c. place the patient in trendelenberg position
d. there is no way to prevent it
-c. place the patient in trendelenberg position
Air embolism can be avoidied by using the trendelenberg positon to increase venous pressure, which limits the possiblity of the entrance of air through the catheter.
- A patient with myasthenia gravis is at major surgical risk for:
a. aspiration pneumonitis
b. hypothermia
c. postoperative ventilatory failure
d. prolonged muscle paralysis after succinylcholine administration
-c. postoperative ventilatory failure
Although muscle strength frequently seems adequate early after anesthesia and surgery, many patients with myasthenia gravis experience deterioration and require ventilatory support after surgery.
- The patient complains of an intense, searing pain upon regional anesthetic injection; what most likely occured?
a. patient really just felt paresthesia
d. the needle hit the bone
c. intraneuronal injection
d. intra-arterial injection
-c. intraneuronal injection
Accidentally pinning a nerve against an ajacent structure increases the likelihood of intraneuronal injection. When this occurs, the injection should be stopped and the needle re-placed
- Name the induction agent of choice for a patient with cardiac tamponade?
a. thiopental sodium
b. propofol
c. etomidate
d. ketamine
-d. ketamine
Ketamine, by releasing catecholamines supports blood pressure. Patients with cardiac tamponade are decompensated and any cardiac depressant drug may cause precipitous hypotension.
- Which lung volume is reduced under anesthesia?
a. total lung capacity
b. residual volume
c. functional residual capacity
d. vital capacity
-c. FRC (functional residual capacity)
Induction of anesthesia consistantly produces a 15-20% reduction in functional residual capacity beyond which occurs in supine position.
- Why does functional residual capacity decreases in the supine or prone position?
a. compliance is reduced as abdominal contents push up against the diaphragm
b. intrathoracic blood volume decreases
c. pulmonary lung resistance increases as a patient’s position changes
d. there is no change in functional residual capacity
-a. compliance is reduced as abdominal contents push up against the diaphragm
Loss of diaphragmatic tone allows abdominal contents to rise up against the diaphragm. The higher position of the diaphragm decreases lung volumes.
- Which intravenous anesthetic directly appresses the adrenal cortex?
a. thiopental sodium
b. propofol
c. etomidate
d. ketamine
-c. etomidate
etomidate inhibits the conversion of cholesterol to cortisone by inhibiting conversion enzymes. This results in adrenal suppression.
- Numbness over the lateral aspect of the thigh may be caused by damage to what nerve?
a. lateral femoral cutaneous
b. common peroneal nerve
c. sciatic nerve
d. ulnar nerve
-a. lateral femoral cutaneous
The lateral femoral cutaneous nerve may be entrapped in the anetrior iliac spine under the inguinal ligament resulting in numbness in the thigh.
- Complications unique to nasotracheal intubation include all of the following except:
a. epistaxis
b. dislogdement of pharyngeal tonsils (adenoids)
c. tracheo-esophageal fistula
d. maxillary sinusitis
-c. tracheo-esophageal fistula
Complications of nasotracheal intubation may include epistaxis, dislodgement of pharyngeal tonsils, eustachian tube obstruction, maxillary sinusitis, bacteremia and gastric distention.
- Dextrose containing solutions are avoided in neurosurgery because they:
a. decrease urinary output
b. provide inadequate intravascular volume
c. promote cerebral edema
d. increase cellular metabolism
-c. promote cerebral edema
Dextrose in water (although isotonic) ACTS as a hypotonic solution, thus increasing brain water which may lead to cerebral edema.
- How much CO2 is dissolved in arterial blood?
a. 10 ml CO2/dL of blood
b. 5 ml CO2/dL of blood
c. 1.5 ml CO2/dL of blood
d. 2.5 ml CO2/dL of blood
-d. 2.5 mL CO2/dL of blood
Carbon dioxide is more soluble in blood than oxygen. It dissolves in plaasma as well as erythrocytes and represents approx 2.5 ml/dl of blood
- At what postconceptual age should a premature infant be scheduled for elective or outpatient surgery?
a. 30 weeks
b. 60 weeks
c. 120 weeks
d. 60 days
-b. 60 weeks
Premature infants younger than 60 weeks postconception are prone to postoperative episodes of obstructive and central apnea for up to 24 hours after surgery.
- Prematurity is deined as birth before ____ weeks gestation?
a. 20
b. 37
c. 45
d. 47
-b. 37
Prematurity is birth before 37 weeks gestation. This is in contrast to “small gestational age” which may describe a full term infant.
- What is the maintenance fluid requirement for a 5 kg patient?
a. 20 ml/hr
b. 22 ml/hr
c. 10 ml/hr
d. 14 ml/hr
-a. 20 ml/hr
The fluid requirements can be determined by the formula of: 4 ml/hr for the first 10 kg; 2 ml/kg for the nest 10 kg; and 1 ml/kg for the remaining kilograms.