More and more pediatric anesthesia cases are scheduled in non operating room (OR) locations. These locations are often far from the main surgical area, and some anesthesiologists feel out of place in these environments because they may not have easy access to anesthesia equipment and helpful personnel. This chapter will review the implications for anesthetizing children in the most common non-OR areas so that you will now feel “in place” when you are assigned there.
The location of the anesthetic does not alter the standard of care with regard to safety standards of monitoring and personnel. At all times, the American Society of Anesthesiologists Guidelines for Nonoperating Room Anesthetizing Locations applies. When total intravenous (IV) anesthesia is administered, it is not necessary to also have a full anesthesia machine with inhaled anesthetics. Children with anticipated difficult airways (ventilation or intubation) should first have their airway safely secured in the main operating room area where there is a full complement of equipment and personnel, and then be transported to the location of the procedure with an endotracheal tube and continuous capnography.
The cost efficiency of anesthetizing children in remote areas may also present an additional challenge. The daily schedule should take into account the time it takes to transport patients between anesthetizing locations and the postanesthesia care unit (PACU). Unexpected delays are common and should be incorporated into the normal scheduling times (so they become expected delays). Ideally, in any given institution, a subset of anesthesiologists will make up the “off-site team” so that differences in preferences and techniques will be minimized and a trusting relationship can develop between members of the team and staff in these areas.
Magnetic Resonance Imaging
General anesthesia for magnetic resonance imaging (MRI) has become easier to accomplish with the advent of MRI-compatible anesthesia machines, monitoring stations, and electronic infusion pumps, which are nonferromagnetic. MRI-compatible temperature monitors are especially indicated for neonates and small infants because the relatively cold environment in the scanner room predisposes this population to hypothermia. These patients should be covered with several layers of blankets and the MRI fan should be turned off. Limiting the volume of IV fluids administered will also minimize hypothermia. There are many possible anesthetic techniques for pediatric MRI. If the child is an outpatient and does not have preexisting IV access, general anesthesia is induced by inhaled sevoflurane. This may occur within the MRI scanner room or at a nearby separate anesthetizing location, depending on the location of the anesthesia machine and supplies.
At our institution, children for MRI undergo induction of general anesthesia by sevoflurane inhalation in an area separate from the scanner, to optimize the use of ferromagnetic equipment that cannot be used in the immediate scanner vicinity. We maintain two induction rooms and two anesthesia machines in a central location between MRI magnets. Maintenance of general anesthesia is most often accomplished using a laryngeal mask airway and sevoflurane in oxygen. This technique reliably eliminates upper airway obstruction that may occur with a propofol infusion and natural airway technique, and administration of ondansetron eliminates nearly all post-operative nausea and vomiting (PONV). Endotracheal intubation is preferred for small infants and neonates. Intubated children who require scans of the head or neck will benefit from the use of an oral RAE tube, because of its lower profile when using a head coil.
The most important anesthetic consideration in MRI is to ensure that no ferromagnetic objects are accidentally brought into the MRI scanner room. In the presence of a strong magnetic field, these objects become dangerous projectile missiles that can maim or fatally injure the patient or personnel ( Fig. 30.1 ). This includes all types of anesthesia equipment, oxygen tanks, IV poles, gurneys, etc. All oxygen tanks in the MRI facility should be made of aluminum. Each MRI facility must have strict safety precautions that limit the number and types of personnel allowed into the scanner area, and protocols should be established to detect metallic objects transported into the facility. We typically monitor the child using a remote access monitor in an adjacent room ( Fig. 30.2 ).
Computerized Tomography
Computerized tomography (CT) scan technology has improved to the point where most scans are so brief that the need for sedation or anesthesia in children has decreased considerably. However, children with severe anxiety or significant medical disease will still require our services. There are few anesthetic implications for the child who requires general anesthesia for a CT scan. Standard anesthesia machines and monitoring devices can be used in close proximity to the child. The anesthesia provider may remain near the child during the scan (with lead protection) ( Fig. 30.3 ) or may leave the room during the brief scan as long as the child’s airway is patent.