The need for pediatric sedation has increased for elective and emergency procedures in nontraditional settings in imaging facilities and elsewhere. Sedation is a wide spectrum of conscious states affiliated with many potential pitfalls before, during and after the sedation period. The goals of pediatric sedation are to guard the child’s safety and welfare, minimize physical discomfort and pain, control anxiety/minimize psychological trauma, maximize potential for amnesia, control behavior/movement for safety of procedure and return patient to state allowing safe discharge.
The American Society of Anesthesiology has defined the levels of sedation based on four physiologic responses (responsiveness, airway, spontaneous ventilation, and cardiovascular function):
Moderate Sedation/Analgesia (“Conscious Sedation”) is a drug-induced depression of consciousness during which the patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.
Deep Sedation/Analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.
The term “minimal sedation” rarely applies to sedation of children, who must be rendered unconscious for most procedures, especially painful procedures. Unlike adults, moderate to deep sedation is required for most pediatric procedures to be performed successfully. However, in patients of any age, even if one attempts moderate sedation, it can rapidly and unpredictably become deep sedation or general anesthesia due to interindividual variability and unpredictable response to medications. Limitations of “the sedation continuum” are recognized, particularly patient response to verbal or tactile stimulation to determine depth of sedation. Future efforts are underway for reformulation of sedation continuum based on objective vital signs monitoring.
Sedation lies on a continuum that extends from fully awake to general anesthesia. This continuum is associated with a variety of adverse effects. From a pulmonary standpoint, oxygen desaturation, hypoventilation, apnea, upper airway obstruction, bronchospasm, laryngospasm, and aspiration are all potential concerns. From a cardiovascular standpoint, hypotension from fasting-related hypovolemia, hypertension from anxiety, pain, hypoxia, hypercarbia, bladder distension, or cardiac dysrhythmias and cardiopulmonary impairment are concerns. Prediction of a patient’s response to medications is limited due to interindividual variability.
Given this variability, individuals who provide sedation must be able to provide rescue therapy further down the sedation spectrum than their intended range; that is, when administering moderate sedation/analgesia one should be able to rescue patients who enter a state of deep sedation/analgesia, and those providing deep sedation/analgesia should be able to rescue patients who may slip into a general anesthesia state. Mastery of a variety of techniques is needed to keep patients safe. Adequate resources for rescue are a prerequisite for moderate sedation.