RADIOLOGY SUITE
Radiologic procedures that may require sedation/analgesia include
a number of imaging modalities such as radiology, ultrasonography, CT, and MRI, as
well as various
interventions that may be directed by the imaging modalities. Such interventions
include percutaneous drain placement, nephrostomy tube placement, percutaneous placement
of feeding tubes, placement of intravascular access catheters, thrombolysis, dilation
of stenotic vessels, embolization of tumors or arteriovenous malformations (AVMs),
and many other interventions. Advances in techniques of imaging, including the integration
of ultrasound, CT, and MRI into the field of diagnostic and therapeutic radiology,
have improved the ability to detect and diagnose disease and have provided new avenues
of therapeutic intervention; the field of interventional radiology is constantly
expanding. Tissue biopsy specimens may be obtained under radiologic guidance with
the aforementioned techniques, and some conditions may be treatable in the radiology
suite. For example, some solid tumors may be treated by guided tissue ablation.
[9]
Painful metastases may be treated by guided
radiofrequency (RF) ablation.[10]
Cerebrovascular
lesions may be treated endovascularly with guidance by digital subtraction angiography.
[11]
Advances in imaging capability, as well as
the availability of advanced endovascular devices and RF probes, has increased the
use of radiology suites and increased the demand for anesthesia services in these
areas.
General Considerations
In diagnostic and, especially, in therapeutic radiologic procedures,
the patient must often remain immobile for prolonged periods. Most procedures may
be accomplished with minimal to moderate sedation/analgesia.[12]
Cooperative patients may be able to undergo procedures with no or minimal sedation,
but obtunded patients or children will require, at a minimum, sedation/analgesia.
In some instances, however, cooperative patients may not tolerate the procedure
because of anxiety or claustrophobia. Patients in the radiology suite may have severe
underlying medical conditions such as cardiovascular, pulmonary, or neurologic disease.
Indeed, they may be in the radiology suite, as opposed to the operating suite, precisely
because their severe underlying disease precludes operative intervention. Finally,
anesthesiologists may be summoned relatively late in the care episode, after failure
of sedation/analgesia administered by the radiologist or nonanesthesia personnel.
Clearly, this situation is undesirable, and open communication between the departments
of radiology and anesthesiology is essential.
The work environment in the radiology suite is frequently ill
adapted to safe anesthetic care of patients. The rooms may be crowded, especially
in older radiology suites or those in which anesthesiologists were not consulted
during the design phase. Bulky radiology equipment may impede access to the patient.
Such equipment includes C-arm radiologic devices, mobile ultrasound machines, and
MRI cylinders in which the patient may be effectively isolated. Patients are frequently
moved during the procedures to facilitate imaging, and if such movement is not coordinated
with the anesthesia team, airway devices or intravascular access may become dislodged.
High-voltage equipment or the presence of intense magnetic fields may result in
current leakage being conducted to the patient by electrically conductive monitoring
leads. Lack of gas scavenging may limit the options of the anesthesiologist should
general anesthesia prove necessary for the procedure. Familiarity of the anesthesia
personnel with the environment in the anesthetizing location is essential to provide
safe patient care.
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