providers Parents are often the best source of information about the child’s expected reaction to the procedure Some parents may know that, despite a pain-free procedural technique using topical anesthetic for a facial laceration, their child will be so fearful of strangers that nonpharmacologic techniques will not suffice Conversely, a parent may express that her child was calm throughout his or her last laceration repair and may only need distraction during the procedure in addition to local analgesia TABLE 129.4 INFORMATION THAT CAN ASSIST CLINICIAN IN DETERMINING TYPE OF AGENT NEEDED FOR PROCEDURAL SEDATION AND ANALGESIA Procedure Patient Agent Expected pain severity Expected pain duration Required duration of immobility Expected distress or fear caused by procedure Current pain rating Prior experiences Developmental age Onset Duration Desired effects Initial reaction to provider Parental expectation Unwanted effects METHODS OF DELIVERY Delivery route of analgesics and sedatives is an important consideration when choosing an analgesic or PSA regimen Pharmacologic factors such as drug onset, absorption, and duration of action can affect choice of delivery The safety of certain medications and regimens should be taken into account; the presence of a working peripheral IV line allows for quick delivery of reversal agents or resuscitation medications Conversely, while an IV delivery route may be preferred in a certain instance, IV placement may not be possible due to body habitus, vein sclerosis, dehydration, or patient cooperation, among others, and a different delivery route must be considered The IM route is not ideal because it causes delayed drug absorption and the dosage of drug given cannot be titrated Subcutaneous (SC) administration can also be an option for certain medications in patients without IV access Also, pain inflicted on the child must not be ignored; IV, IM, and SC routes are painful Oral medications can be a good option if there is no contraindication, however the onset of action can be delayed compared with other routes The intranasal (IN) delivery route has gained popularity IN drugs have several advantages, including faster absorption compared with oral or IM, no first-pass metabolism, and avoidance of a painful needle stick Some children find the nasal route noxious IN medications should be administered into the well-vascularized nasal vestibule Volumes of 0.3 mL or less are easily absorbed, while larger volumes may run off into the posterior pharynx Although IN medications can be administered by dripping, spray, and nebulization, the majority of recent studies have used atomization into each nostril to increase surface area and decrease swallowing of the drug The ideal medication for the IN route has a low molecular weight, is highly lipophilic, and has neutral pH Conditions that may affect IN drug absorption include presence of blood or nasal secretions, impaired ciliary function, or anatomical conditions such as polyps SEDATIVES The sedative/hypnotic agents include benzodiazepines, chloral hydrate, barbiturates, etomidate, propofol, and nitrous oxide (N2 O) Ketamine is considered a dissociative agent and has both sedative and analgesic properties Dexmedetomidine, an α2 -adrenoceptor agonist, also provides both sedation and analgesia The relative advantages and disadvantages of these agents are listed in Table 129.5 Benzodiazepines Some children who are undergoing painless procedures may be too young, anxious, or emotionally labile to remain still enough for the procedure to be successful Benzodiazepines can provide anxiolysis, sedation, muscle relaxation, and amnesia during frightening or painful procedures such as CT scans, echocardiography, and electroencephalography It is important to remember that these agents not provide any analgesia and should not be used alone for painful procedures Benzodiazepines depress all levels of the central nervous system (CNS) by binding to the γ-aminobutyric acid (GABA) receptor complex and modulating GABA, which is a major inhibitory neurotransmitter in the brain Of these, midazolam is considered the most efficacious during PSA, offering the advantage of rapid onset, rapid offset, and relatively wide therapeutic range The other distinct advantage of midazolam is the multiple potential routes of administration, including IM, oral, and IN Parenteral administration is the fastest and more reliable method; however, it requires another painful procedure (IV placement or IM injection) Children tolerate oral midazolam well; it is less intrusive or irritating than other routes and its onset of action is approximately 10 to 20 minutes IN midazolam has an onset within minutes, however as mentioned above it can be very irritating to the nasal mucosa One study comparing midazolam administered either IN, oral, or buccal routes found the IN group had a higher percentage of children achieving adequate sedation and higher parent satisfaction It is important to note that instead of the anticipated effect of sedation, benzodiazepines can cause hyperactivity, agitation, and restlessness, known as a paradoxical reaction, in less than 1% of children and adults To date, there are no identified factors that predict which child will have a paradoxical reaction and treatment is largely supportive, although some case reports state flumazenil may be effective Since benzodiazepines have no analgesic properties, they are often used concomitantly with analgesics during painful procedures This combination can lead to more side effects, particularly respiratory depression, than use of either drug alone A reversal agent, flumazenil, can be used in case of severe adverse effects due to benzodiazepine administration The initial dose of flumazenil is 0.01 mg/kg (maximum dose 0.2 mg) and may be repeated every minute to total maximum dose of mg The duration of action is less than 60 minutes, so sedation may reoccur if medium- or long-acting benzodiazepines are used Chloral Hydrate Chloral hydrate, once a widely used sedative for young children and infants, has fallen out of favor due to its unreliable onset and duration and side effect profile Chloral hydrate has no analgesic effects, but at recommended doses produces a light level of sleep and allows airway reflexes to be maintained Chloral hydrate is absorbed rapidly through the oral or rectal mucosa, and is then metabolized by the liver to trichloroethanol, the active ingredient Although the transmucosal absorption avoids the need for a painful needle stick, the variable onset and long duration of action of chloral hydrate render it less useful in most emergency situations Other clinically significant adverse effects seen are respiratory depression, hypotension, cardiac dysrhythmias, and vomiting Also less common but worrisome side effects include esophagitis, enteritis, and intestinal perforation Paradoxical excitability may occur, particularly in children with developmental delay or pre-existing emotional problems The cardiorespiratory effects can be more pronounced in very young infants or those born prematurely, and the dosage, monitoring, and observation periods should be adjusted accordingly ... the variable onset and long duration of action of chloral hydrate render it less useful in most emergency situations Other clinically significant adverse effects seen are respiratory depression,