Neurosurgery

neuroradiology and, as these procedures are often prolonged and uncomfortable, general anesthesia or sedation may be needed. Additional factors reducing patient acceptability of the MRI scanner are claustrophobia and the loud noise during scanning. Patients who need anesthesia or sedation include infants and children and confused or mentally ill adults. Unconscious or critically ill patients will need airway protection and ventilatory and cardiovascular support.

Procedures for which anesthesia may be required include computerized axial tomography (CAT scan), myelography, angiography and interventional radiology. The X-ray department is sometimes considered to be a hostile environment for anesthesia, and patient access may be limited, but exactly the same standards of monitoring and patient care are needed as in the operating room.

The requirements for anesthesia are similar to those for neurosurgery and include avoidance of fluctuations in heart rate and blood pressure, prevention of hypoxia, hypercapnia and raised venous pressure, and rapid recovery to allow for early neurological assessment. In many cases the laryngeal mask airway can be used to maintain the airway and avoid the need for intubation. Angiography in adults under local anesthesia with sedation may provide greater cardiovascular stability than with general anesthesia [26].

Many conditions are now treated by inter-ventional neuroradiology, including arteriove-nous malformations (AVMs), vascular tumors and aneurysms. Sometimes frequent neurological assessment is needed during the procedure, e.g. during embolization of AVMs. The patient needs to be awake and able to cooperate with testing but can be sedated for comfort between assessments. Propofol, with its rapid onset and offset of action, is ideal for this purpose. Sedation of this kind should be administered by an anesthesiologist as respiratory depression and even apnea can easily ensue. Adequate monitoring must be used, including pulse oximetry, ECG and blood pressure monitoring, and supplemental oxygen should be available. Equipment and drugs to support the airway, breathing and cardiovascular system must be readily available.

Endovascular obliteration of aneurysm sacs through superselective catheters placed during angiography is an increasingly popular alternative method of treatment to surgical clipping. The procedure can be prolonged in particular with large aneurysms and, as there is less need for patient assessment during the procedure, general anesthesia is often used for patient comfort.

The strong magnetic field of an MRI scanner can interfere with monitoring and anesthetic equipment. At the same time the equipment can cause degradation of the nuclear magnetic signals, leading to poor-quality images. Because of the strength of the magnetic field, ferromagnetic objects can become dangerous missiles in close proximity to the scanner and must be excluded or adequately secured. Special non-ferromagnetic equipment is available but adds significantly to the cost. Metal objects distort the field and result in poor image quality, and can also heat up and cause burns when subjected to radiofrequency electromagnetic fields. Reliable and accurate monitoring is essential in the MRI scanner as the patient cannot be easily seen and is remote from the anesthesiologist. Artifacts can be induced in the ECG by the radiofre-quency currents but can be minimized by the use of shielded cables, telemetry or fiberoptics. ECG electrodes must be non-magnetic and should be place carefully to reduce artifacts. Shielded MRI-compatible oximeters are available. Good airway control is important, as the anesthesiologist is not easily able to intervene if airway obstruction develops during the scan. The laryngeal mask airway is ideal for this purpose.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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