Review Exam 1 Chapter 21 Flashcards
CO and BP are often decreased in which positions (select all that apply) A. Sitting B. Prone C. Flexed Lateral D. Supine
Sitting, Prone, Flexed Lateral
(anywhere that lower extremities are dependent) pg 403
Hemodynamic changes are generally minimal in which positions (select all that apply) A. Supine B. Prone C. Lateral D. Lithotomy
Supine and Lateral
In the prone position, CVP is (increased or decreased), LV volume is (increased or decreased)?
CVP increased, LVV reduced
(probably due to decreased venous return and increased thoracic pressure. CI may be decreased or unchanged in the prone position and may depend on the frame used). Pg 403
Elevation of the legs in the lithotomy position may increase BP due to autotransfusion of how much blood per leg? A. 80-100 mL B 100-250 mL C 200-300 mL D 500 mL
B 100-250 mL per leg
Pg 403
MAP increases or decreases by approximately _____mmHg per inch for each change in height between the heart and body region?
A 1
B 2
C 3
D 4
B. 2 mmHg
Therefore regions elevated above the heart in the head up, sitting, or lithotomy positions may be at risk for hypoperfusion and ischemia, particularly if hypotension occurs. pg 403
For a pt in the head-up sitting position, when raised to 90 degrees, CO can decrease by as much as _____% due to blood pooling in the extremities.
20%
PG 403
When the pt is in the seated position, as compared to supine, CI is (increased or decreased), CVP (increased or decreased), PCWP (increased or decreased) and SVR is (increased or decreased)?
A. CI decreased, CVP decreased, PCWP increased, SVR decreased
B CI decreased, CVP decreased, PCWP decreased, SVR decreased
C CI increased, CVP increased, PCWP decreased, SVR increased
D CI decreased, CVP decreased, PCWP decreased, SVR increased
D. all decreased except SVR which is increased.
In procedures in which the head is elevated and CPP is a concern, A line monitoring should be used with the transducer at the level of the COW. (pg 403)
Proper positioning of the kidney rest in a pt in the lateral decubitous position is:
A under the dependent flank
B under the dependent last rib
C under the dependent iliac crest
D. under the dependent greater trochanter
C. Under the dependent iliac crest.
elevation of the kidney rest under the flank may cause vena cava compression. pg 403
Explain how large tidal volumes and peep affect atrial filling and cardiac output.
By increasing intrathoracic pressure, there is a subsequent reduction in atrial filling and cardiac output.
Name four interventions that may attenuate some position induced hemodynamic changes:
Slow assumption of surgical position, nitrous/narcotic technique that allows for a MAC <0.5, gradually attaining the desired MAC, intravascular volume loading prior to positioning (in pts not susceptible to volume overload).
PG 403
The combination of lithotomy and __________ may have a detrimental effect on myocardial function in pts with CAD.
A. Left Tilt
B. Right Tilt
C. Reverse Trend
D. Trend
D. Trendelenberg
because CVP, PAP, and PCWP are increased, whereas CO is decreased. The Trendelenberg position may increase myocardial work by increasing central blood volume, CO, and SV- pts with poor cardiac fxn have decreased CO if the central blood volume is increased. THEY MOVE TO A WORSE POSITION ON THE FRANK STARLING CURVE.
The lower extremities of pts with PVD may be at risk of ischemia in which positions? (select all that apply) A. Lithotomy B. Reverse Trend C. Trend D. Prone
A and C. Lithotomy and Trend because a relative state of hypoperfusion exists when the lower extremities are elevated above the heart.
Pg 404
Positional changes my result in redistribution of ventilation and perfusion. These changes are less in the \_\_\_\_\_\_\_\_ position and more evident in \_\_\_\_\_\_ and \_\_\_\_\_\_\_\_ positions. A. Sitting, prone, lateral B. Prone, supine, lateral C. Sitting, supine, prone D. Prone, sitting, lateral
A. Less in sitting, more evident in prone and lateral.
Pg 404
T or F: In the prone position changes in V/Q ratios have been postulated as the cause of improved oxygenation.
True
More lung volume is present posteriorly than anteriorly as anterior mediastinal structures occupy a lot of space, so posterior lung segments are better ventilated. Ventilation is more uniform and V/Q matching is better in the prone position than in the supine position. PG 404
T or F: In the lateral position, ventilation and perfusion are greater in the dependent lung, than in the nondependent lung of awake, spontaneously breathing patient.
True
Pg 404
Patients are susceptible to atelectasis in the lateral position because \_\_\_\_\_\_\_\_\_\_\_ occurs above \_\_\_\_\_\_\_\_\_\_\_. A. closing volumes, FRC B. FRC, Vital Capacity C. FRC, Residual Volume D. closing volumes, ERV
A. Closing volumes, FRC
Closing volumes occur above FRC with closing occuring earlier in the dependent than in the nondependent lung.
Pg 404
In one lung ventilation, administration of oxygen at \_\_\_\_\_\_\_\_L/min to the non-ventilated lung can significantly improve oxygenation, as well as the addition of 5-10 cm H20 of CPAP. A. 1-2 B. 2-4 C. 5-6 D. 8-10
B. 2-4 L/min
Pg 404
In anesthetized patients in the lateral position, abdominal contents shift (cephalad/caudad) thereby (increasing/decreasing) ventilation in the dependent lung?
cephalad, decreasing and reducing the compliance.
In the nondependent lung the ventilation is greater, and teh compliance increased due to the caudal shift of the upper hemidiaphragm allowing unrestricted lung excursion.
Pg 405
In the awake pt ventilation favors the (dependent/non-dependent) lung. With the addition of anesthesia, PPV, and paralysis the (dependent,nondependent) lung is easier to ventilate?
dependent, non dependent. Due to the displacement of the relaxed diaphragm by abdominal viscera and downward force of the mediastinum resulting in decreased compliance of the lower lung.
Name the four primary mechanisms for nerve injury.
Transection, compression, stretch, kinking.
Pg 405
In the exaggerated lithotomy position, which type of nerve injury is most likely to occur to the femoral nerve A. Transection B. Compression C. Stretch D. Kinking
Kinking
The femoral nerve can be kinked under the inguinal ligament when thighs are flexed up.
A common component of all peripheral nerve injuries is ________
ischemia
High or low mean arterial blood pressure may augment the development of ischemic conditions?
Low. Pressure applied over a body surface may limit venous capillary outflow causing a rise in venous capillary pressure and a decrease in the hydrostatic pressure gradient between interstitial tissues and the capillary. Ultimately tissue edema occurs as fluid is sequestered in the cells and interstitial space. As venous capillary pressures rise, the A-V pressure gradient is reduced, decreasing flow to tissues along the capillary. If arterial pressure is low, it is quicker to become obstructed and ischemia results.
True or False, tissue metabolism continues in the absence of blood flow?
True, when ischemia ensues, ATP production is decreased, causing failure of the NaK pump and accumulation of Na in the cell….which results in the osmotic gradient favoring fluid moving into the cell—intracellular volume increases = edema.
Peripheral nerves are composed of bundles of nerve fibers known as ________.
fascicles
Pg 406
Each nerve fiber is composed of one or more axons sheathed by _____________.
Schwann cells (neurolemma) that are either myelinated or unmyelinated.
The axons and the neurolemma are covered by a loose connective tissue called the _____________.
endoneurium
The __________ is a tough connective tissue that binds the fascicles into identifiable structures.
perineurium
