Pediatric Non-Operating Room Anesthesia

Introduction

• NORA has rapidly expanded to include care of patients for medical and procedural specialties. Although some procedures are considered minimally invasive, the anesthetic implications can be significant.¹
• Unique challenges associated with NORA include:
  • Remote location far from familiar staff and resources
  • Limited access to the patient
  • Unfamiliar or outdated equipment
  • Suboptimal lighting and insufficient power supplies
  • Variability in anesthesia setup
  • Staff and proceduralists with limited medical or anesthesia background may not be familiar with standards and spectrum of anesthesia care (for example, NPO guidelines, children with anxiety, patient tolerance, etc.)
  • Distance from postanesthesia recovery unit (PACU)
• The American Society of Anesthesiologists (ASA) published a statement recommending adherence to the same ASA standards for preoperative evaluation, monitoring, and postanesthesia care recovery must be maintained in remote locations to ensure patient safety.²

NORA Setup

• Each anesthetic should be tailored to the unique patient needs, comorbidities, and imaging or procedure requirements.
• Per the ASA guidelines, each NORA site must include the following:²
  • Dependable source of oxygen, including a backup supply
  • Self-inflating resuscitation bag that can deliver positive pressure ventilation
  • Reliable source of suction
  • System for scavenging waste anesthetic gases if inhalation anesthetics are administered
  • Sufficient electrical outlets and emergency power supply
  • Adequate lighting
  • Ability to access patient, anesthesia machine, and monitoring equipment
  • Appropriate anesthesia drugs, IV fluids, and monitoring devices (including capnography)
  • Readily available emergency drugs and defibrillator
  • Ability for the anesthesia provider to request more assistance
  • Dedicated on-site PACU or ability to safely transport to a PACU

Radiology Suite: Computed Tomography and Magnetic Resonance Imaging

• The ability of pediatric patients to cooperate with laying still, even for noninvasive imaging, depends on the patient’s age and cognitive and emotional development.
• Computed tomography (CT) is typically brief, requiring a few minutes to obtain imaging, and may be completed with minimal or no anesthesia. Distraction technologies, child life specialists, parental support, or premedication can be employed to assist the child. CT-guided diagnostic or therapeutic procedures are more invasive and can be performed with sedation or general anesthesia.³
• The longer duration of magnetic resonance imaging (MRI) and the need for the patient to remain motionless for accurate imaging often require sedation or general anesthesia. In many cases, children can be safely sedated with a propofol infusion and natural airway with careful monitoring. Patient comorbidities or specific requirements for imaging, such as positioning, breath holding, or administration of oral contrast, may necessitate general anesthesia with an invasive airway.^1,4,5
• The MRI magnet is always on. Objects that are not MRI-compatible can become projectile and are a serious hazard to patients and surrounding personnel. The zone closest to the MRI scanner should be free of ferromagnetic objects, and patients and personnel working in the area should be screened prior to entering.⁵
• The anesthetic typically begins in an induction area separate from the MRI scanner. MRI-compatible monitors (nonferromagnetic EKG leads, blood pressure cuff, pulse oximeter, temperature probe, and end-tidal CO₂) are usually applied here prior to transport to the scanner. Direct contact of monitors with the patient’s skin should be avoided to decrease the risk of thermal injury. The magnetic field from MRI can interfere with monitors, creating artifacts.⁴
• Extensions for circuits, suction tubing, intravenous (IV) lines, and infusion pumps are needed.

Interventional Radiology

• A wide range of procedures can be executed with moderate or deep sedation to general anesthesia depending on the complexity and duration of the procedure, need for neuromuscular blockade, patient comorbidities and positioning.⁶
• Common medications utilized include midazolam, ketamine, dexmedetomidine, propofol, and opioids in combination with local anesthetic infiltration from the proceduralist.
• Fluoroscopy equipment is bulky and occupies large space, frequently limiting access to the patient, IV lines, or monitors. Extension tubing is often necessary.
• Invasive arterial monitoring may be indicated in some scenarios, especially for neuro-interventional procedures.
• Femoral endovascular access requires the patient to remain supine for several hours postprocedure. A smooth emergence and minimizing coughing reduce the risk of bleeding. Dexmedetomidine is a useful agent to reduce agitation and facilitate adherence to laying supine without respiratory compromise.⁵

Nuclear Medicine

• Positron emission tomography (PET) scans are done to diagnose disease states and for disease surveillance. Radiotracers, which are absorbed by the patient, emit small amounts of ionizing radiation that are captured by the scanning device.⁷
• PET most commonly utilizes the radiotracer 18F-FDG (fluorodeoxyglucose). Its short half-life of 110 minutes reduces radiation exposure compared to other commonly used radionuclides. FDG is cleared from the blood by urinary excretion.
• Imaging should be obtained an hour after IV administration of the radiotracer. These scans are not painful, and the procedure does not need analgesia. Anesthesia is used for patient cooperation and maintaining patient stillness, as motion influences image quality.⁵
• In most cases, sedation with a natural airway is appropriate. However, if the patient is obstructing or motion affects image quality, escalate to advanced airway management.
• Anesthetic agents do not interact with the radioactive tracer; volatile and IV agents are acceptable.
• Pregnant women should avoid contact with patients undergoing PET scans to minimize the risk of exposure to the fetus.⁷

Oncology Suite

• Oncology patients undergo many anesthetics for diagnosis and treatment. Radiation therapy consists of numerous sessions where sedation is required.⁵
• Prior to starting therapy, patients undergo scanning to precisely map the area of radiation treatment to avoid injury to healthy tissue and minimize treatment failure.
• A custom face cast is made initially and used during successive treatments. If any device, such as an oral or supraglottic airway, is used for the initial scan, these devices are needed for each subsequent session to ensure proper cast fitting.
• A variety of anesthetic medications can be used for radiation therapy, with IV propofol sedation with a natural airway being the most common technique used.
• Due to the risk of radiation exposure, anesthesia providers monitor the patient remotely with EKG, blood pressure, pulse oximetry, and capnography. It is vital to ensure that adequate ventilation and depth of anesthesia can be assessed frequently by direct visualization or video monitoring.⁵

Endoscopy

• Endoscopic procedures are common in the pediatric population and often require a deeper level of sedation or anesthesia compared to adults.
• Most pediatric patients may not tolerate IV access; inhalation induction is needed.
• Propofol sedation with a natural airway is an appropriate technique for most endoscopies and colonoscopies. However, patients at an increased risk of pulmonary aspiration or those requiring complex, prolonged procedures should receive general anesthesia.
• An endoscope can cause external compression of the airway, leading to upper airway obstruction and necessitating an endotracheal tube for airway support.
• Endoscopic retrograde cholangiopancreatography (ERCP) is typically performed with deep sedation or general anesthesia. ERCP is associated with an increased risk of airway complications.
• Most complications are related to inadequate oxygenation and ventilation or oversedation.^4,7

NORA Emergencies

• All emergency supplies should be available before inducing anesthesia in an off-site location.
  • This includes resuscitative equipment, such as airway supplies, medications (weight-based drug reference manual), and a code cart with a defibrillator.
  • Per the Malignant Hyperthermia Association of United States (MHAUS) recommendations, dantrolene must be available at all anesthetizing locations where malignant hyperthermia trigger agents are used.⁸
  • In a closed claims database study, the proportion of adverse respiratory events in NORA claims was double the rate of OR claims. One-third of adverse events in the NORA environment were associated with inadequate oxygenation/ventilation.⁴
• Perioperative anaphylaxis is a severe adverse event that requires immediate diagnosis and treatment.⁹
• Anaphylactic reactions during contrast administration can occur even with previous contrast exposure. Gadolinium and iodine-based contrast media are generally safe, but patients can still experience reactions that are classified as anaphylactoid or nonanaphylactoid.
• Patients can present with significant hypotension, cutaneous flushing, angioedema, and respiratory symptoms such as stridor or wheezing.
• Treatment consists of the following:
  • Discontinue the contrast, stop the imaging or procedure, increase oxygen to FiO₂ of 1.0, and secure the airway if not done already
  • Administer 10-30 mL/kg crystalloid bolus, methylprednisolone 2mg/kg IV and epinephrine 1-10 mcg/kg IV to decrease mediator release and support hemodynamics, H1 or H2 blockers such as diphenhydramine or famotidine may be used to decrease histamine-mediated effects, and albuterol to decrease bronchoconstriction
  • Consider an epinephrine infusion starting at 0.05 to 0.1 mcg/kg/min if numerous boluses of epinephrine are needed
  • Please see the OA summary on perioperative allergies and anaphylaxis for more details
• Anesthesia providers should also be prepared for emergencies in the MRI suite.
  • There should be a designated emergency area outside the scanner where all emergency equipment and medications are accessible.
  • In an emergency, the first step is to remove the patient from the scanner and transfer to the designated emergency area. This is important to avoid any ferrous material on equipment or personnel from harming the patient or staff.
  • In a life-threatening emergency, the magnet can be quenched. During a quench, the quench duct should evacuate the gas out of the building. If not properly vented, the large quantity of gases can displace oxygen inside the MRI suite, leading to hypoxia for both patient and staff members.¹⁰
  • Please see the OA summaries on MRI safety and advanced MRI safety for more details