Anesthesia and the neurosurgical patient: part II--neuroradiologic procedures.

In Part II of a continuing series on neuroanesthesia, the author discusses the many variables in managing anesthesia for neuroradiologic procedures, encompassing pneumoencephalography, angiography, myelography, and computerized axial tomography (CA T scans). From the discovery of the X-ray to the introduction of computed tomography, the one basic and most important requirement for obtaining a satisfactory and interpretable neuroradiologic study is the immobilization of the patient to be examined. Movement during the study will only increase the complication rate with repetition and will subject the patient to additional and unnecessary radiation exposure. Nurse anesthetists should be somewhat familiar with neuroradiologic diagnostic tools, the position of patients for the various procedures and the anaphylactic reactions which may occur with the use of iodinated contrast material. 1 Most radiology suites are situated away from the operating rooms, either on a different floor or even in a different wing of the hospital. Because of the isolation of radiology suites, nurse anesthetists must be even more aware of proper functioning anesthesia equipment, availability of adequate suctioning devices, and all possible drugs that might be needed. These are only a few of the ways that we can provide the patient with the best care possible. Before a procedure begins, be sure that ventilation , monitoring and resuscitation equipment is immediately available in the radiology suite. ECG monitoring is essential, especially if controlled ventilation is used. Arrhythmias may be the earliest sign that pressure is developing on the brain stem. Intravenous sedation may be used in the neu-roradiologic procedures. If this is the anesthetic technique being considered, it is extremely important that the anesthetist is able to view the patient at all times to determine that the airway is patent and that respiration remains optimum in order to avoid a rise in the carbon dioxide level which would, in turn, increase the intracranial pressure. The ECG should be monitored in the same manner as in a general anesthetic. A pre-cordial or esophageal stethoscope should be used for monitoring the breath sounds and heart tones. The choice of whether the procedure should be under local sedation or general anesthesia is dependent on several factors. Will the young child or older adult be able to remain still or will the fear and lack of understanding prevent their im-mobilization? This is a "foreign" area for many patients and, understandably, apprehension and anxiety run high. Can the semicomatose patient follow commands? …