Intraoperative Monitoring Data Flashcards
What are the potential complications of arterial
cannulation for blood pressure monitoring and what
are the factors that increase the incidence of these
complications?
Factors associated with an increased risk of complications due to
intra-arterial monitoring such as thrombosis, vasospasm,
infection, hematoma, nerve damage, and loss of digits include
female gender, hyperlipidemia, prolonged cannulation, repeated
insertion attempts, hyperlipidemia, and use of vasopressors.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 93-94
How does the presence of air in an arterial pressure
monitoring tubing system affect the estimation of the
blood pressure? What about the presence of
stopcocks in the system?
The presence of air in the transducer tubing and the addition of
stopcocks and longer tubing can decrease the frequency of the
monitoring system and lead to overdamping which will tend to
underestimate the systolic blood pressure.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 95
What are Korotkoff sounds?
Korotkoff sounds represent the audible representation of the pulse
when checking the blood pressure using a stethoscope. When
assessing the blood pressure using a blood pressure cuff and a
stethoscope, the onset of Korotkoff sounds indicates the systolic
blood pressure and the disappearance of the sounds indicates
diastolic blood pressure.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 90.
How does the position of the arm affect the accuracy
of non-invasive blood pressure monitoring?
If the NIBP cuff is not level with the heart, then a correction must
be made to compensate for the difference between arm and
systemic pressure. For every 10 cm the cuff is above the level of
the heart, you must add 7.5 mm Hg to estimate the systemic
pressure accurately. Likewise, for every 10 cm the NIBP cuff is
below the level of the heart, you must subtract 7.5 mm Hg to
correctly estimate the systemic pressure.
Dorsch JA, Dorsch SE. Understanding Anesthesia Equipment.
5th ed. Philadelphia, PA: Lippincott Williams and Wilkins, 2008:
839.
If a patient with severe peripheral vascular disease
exhibits different blood pressures in each arm, which
one should you use?
If the blood pressure readings between two extremities vary
significantly in patients with peripheral vascular disease, you
should record the higher pressure.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 88.
What are the components of a central venous
pressure waveform and what does each represent?
A central venous pressure tracing exhibits several waveforms
worth noting: the a wave represents atrial contraction, the c wave
represents elevation of the tricuspid valve during ventricular
contraction, the v wave represents venous return against a closed
tricuspid valve, and the x and y descents represent downward
displacement of the ventricle during systole and opening of the
tricuspid valve during diastole.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 104.
What component of a central venous pressure
waveform would be missing in a patient with atrial
fibrillation?
Because it represents atrial contraction, the a wave would be
absent in patients with atrial fibrillation.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 104.
What are somatosensory evoked potentials? When
are they used?
Somatosensory evoked potentials assess the dorsal spinal column
and sensory cortex and are best for monitoring during spinal
surgery, carotid endarterectomy, and aortic surgery.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 134.
What are visual evoked potentials and when are they
used?
Visual evoked potentials assess the integrity of the optic nerve and
upper brainstem and are best for monitoring during pituitary
resection.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 134
What are brainstem auditory evoked potentials and
when are they used?
Brainstem auditory evoked potentials assess the integrity of the
8th cranial nerve and the auditory pathways above the pons and
are best for monitoring during posterior fossa surgery.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 134.
What is the difference between capnometry,
capnogram, and capnography?
Capnometry refers to all methods of measuring carbon dioxide
levels. A capnogram is a continuous display of measured CO2
levels. Capnography is the recording of a CO2 measurement.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 315
What can cause a slope in the plateau phase of the
capnograph
A slope in the plateau represents prolonged exhalation and can
result from obstruction of expired gases, COPD, or a V/Q
mismatch.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 316.
Does the presence of ETCO2 on the capnograph rule
out esophageal intubation?
No, positive pressure ventilation by mask can force air into the
stomach. On esophageal intubation, there may be a short-lived
indication of CO2 on the capnograph. The presence of persistent
ETCO2, however, is a useful aid in confirming endotracheal
intubation.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 316.
What are the most common factors that decrease the
ETCO2 measurement?
Hypothermia, hypothyroidism, hyperventilation, hypoperfusion, and
pulmonary embolism all result in a decreased ETCO2.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 705.
What are the most common factors that result in an
increased ETCO2?
Hyperthermia, sepsis, malignant hyperthermia, shivering, and
hyperthyroidism are all factors that increase the metabolic rate and
subsequently, the amount of carbon dioxide produced.
Hypoventilation and rebreathing are non-metabolic causes of an
increased ETCO2.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 705.
