Special pediatric disorders

Perioperative management

Patients with ASD have characteristic behaviors that impede their ability to cope with a diagnostic or surgical procedure requiring anesthesia care, including impaired communication and social skills, restrictive interests, repetitive behaviors, sensory issues, poor problem-solving abilities, and a high level of stress and anxiety. Because most children with ASD function best in predictable routine environments, being in a healthcare setting creates a highly stressful situation that may trigger maladaptive behaviors, including refusal to cooperate, refusal to take oral premedication, temper tantrums, and aggressive outbursts. These patients can be highly sensitive to the visual, tactile, and auditory stimuli of the perioperative setting, and even simple stimuli such as placing monitors or a face mask may overwhelm them. There is great variation in the severity of ASD in addition to the needs and the behavior of each individual patient. Therefore a key principle in the successful management of these patients is early communication with the family well ahead of the day of the procedure to develop an effective, individualized perioperative and anesthetic care plan so that the entire experience is as safe and comfortable as possible ( ; ). When the patient’s caregiver functions as an expert advisor, the unique needs of each patient can be best served. Because patients interact with a number of different healthcare providers other than the anesthesia team, a multidisciplinary approach, including nursing, anesthesia, and child life specialists, is most effective. An individualized healthcare plan for patients with developmental and behavioral challenges should be developed prior to the planned procedure in consultation with the patient and family to evaluate and plan accommodations for the child’s particular needs ( ). Elements of such a plan include minimizing waiting time, providing a quiet environment, knowing how to effectively communicate with the child, encouraging active participation by the child’s caregivers, ensuring that the patient’s personal toys and security items are present, providing appropriate distraction, and avoiding restraint when possible ( ). Child life specialists often develop such a plan and provide preoperative visits to the institution to familiarize the patient with the environment and the planned procedure. Preoperative consultation with the anesthesiologist may be helpful to develop an appropriate anesthetic plan, including the details of premedication, induction, emergence, and discharge ( ). The plan must be individualized, coordinated, and flexible should the need for alternative approaches arise. If the patient requires repeated anesthetics, this “adaptive care” plan can serve as a template for future encounters. If the patient requires multiple procedures under anesthesia, it is best to coordinate them during a single anesthetic.

Premedication of the patient with ASD is often necessary to facilitate the safe and reasonably smooth induction of anesthesia. It may be helpful to administer a nonsedating oral anxiolytic medication (diazepam or clonidine) at home under supervision of the child’s pediatrician before arrival at the healthcare institution. Contraindications to medication at home include major craniofacial airway abnormalities, sleep apnea, and significant cardiac disease. Benefits include decreased distress, improved patient experience, and better patient compliance for future visits ( ). Premedication shortly before induction of anesthesia is commonly accomplished with oral midazolam. However, the effects in patients with ASD may be unpredictable, and sedation may not be sufficient to allow for smooth induction ( ). Ketamine, which has minimal adverse reactions and is available in intravenous (IV), intramuscular, and oral dosing routes, is an effective and reliable preoperative sedative for patients with ASD ( ). Oral ketamine has a 17% bioavailability, compared with 93% when given intramuscularly or intravenously ( ). Oral ketamine and midazolam in combination may be especially helpful for patients with severe ASD. Oral or nasal (1 to 2 mcg/kg) dexmedetomidine has also been used. Currently, there is a lack of high-quality evidence to suggest best premedication practices ( ). A topical anesthetic cream is applied if an IV induction is planned. Depending on the degree of sedation and cooperation achieved, a mask induction or IV induction is chosen. Parental presence may make the induction smoother. Intramuscular ketamine (4 to 5 mg/kg) may be needed if the patient is agitated or combative on induction (see Chapter 16 , “Preoperative Preparation”). The use of music, video, television, toys, and electronic devices such as smartphones and tablets may be useful distraction techniques during the induction ( ; ). The use of restraints should be avoided whenever possible and should be discussed with the family beforehand.

Adequate analgesia, IV hydration, and antiemetic prophylaxis are important for a smooth recovery period. Although emergence agitation is a fairly common occurrence in pediatric patients, patients with ASD may react especially poorly to changes in their routine, and waking up in strange surroundings can be alarming for them. A bolus dose of dexmedetomidine (0.5 to 1 mcg/kg IV) given toward the end of the anesthetic may help prevent emergence agitation and may also be used to treat it in the recovery period. Involving parents early in the recovery phase; providing a quiet recovery environment with reduced noise, movement, and light; and removing IV catheters early all help promote a smooth recovery. Ambulatory anesthesia with early discharge allows these patients to return to their normal environment and routine as soon as possible. Should admission be required, it is important to acknowledge that parents have a wealth of knowledge about their child and to provide care in a true partnership with them. Although excellent review articles have been published ( ), there is an urgent need for more research to establish an evidence base upon which to improve clinical practice. Proactive preanesthetic evaluation, individualized treatment plans that are multidisciplinary and flexible, and implementing appropriate adaptations are critical to making the anesthetic experience more comfortable and less stressful for these patients and their families.

Preoperative assessment and care

Although the general health and emotional status of each child should be noted before induction of anesthesia, the preoperative assessment of the child with DS should focus particularly on the cardiovascular system, the airway, and the cervical spine. The goal of preoperative assessment is to optimize patient safety by choosing the appropriate setting and perioperative personnel and to identify risk factors that can be mitigated by preparation and intervention.

Outside the neonatal period, the DS patient undergoing anesthesia should be previously assessed by a cardiologist, including an echocardiogram by 6 months of age, as recommended by the AAP ( ). Regular follow-up with a cardiologist is imperative, particularly if the patient has a repaired lesion, as significant structural disease may not result in audible murmurs or be readily apparent by history. The newest American Heart Association guidelines should determine which children require antibiotic prophylaxis for subacute bacterial endocarditis ( ).

The patient’s respiratory status should be evaluated with a detailed history. Particular interest should be given to prior airway surgery and persistent symptoms of sleep-disordered breathing, including snoring, pauses in breathing, restless sleep, or daytime somnolence. A past history of croup or recent upper respiratory tract infection should raise a red flag, as postanesthesia upper airway complications and complications after ear/nose/throat (ENT) surgery are more frequent in patients with DS ( ). Children with DS are prone to multilevel upper airway collapse, often rendering their obstructive symptoms resistant to the standard first-line surgical treatment of adenotonsillectomy ( ). Drug-induced sedation endoscopy allows direct visualization of the airway at multiple levels during spontaneous breathing, demonstrating the type and degree of airway obstruction. The results may direct further surgery without the need of another sedation or hospital admission ( ).

Although routine cervical spine radiographs are not recommended in asymptomatic patients with DS for elective surgery, a careful and focused history probing for signs of neurologic change or deterioration should be elicited, followed by a physical examination to assess range of motion, strength, and reflexes ( ). These deficits may be difficult to identify in developmentally delayed patients. Subtle findings, such as reduced physical activity or reduced use of an extremity, may be present. Pain may occur in the neck, occiput, or head. More pronounced findings may include frank weakness or paralysis in the upper or lower extremities and gait disturbances. Although this is a high spinal cord pathology, the symptoms may present in the lower extremities ( ; ). If new neurologic deficits are present, further evaluation of the cervical spine and neurosurgical consultation are indicated before proceeding with elective surgery. For urgent surgery, the DS patient should be treated with appropriate cervical spine precautions.

Premedication

Like many pediatric patients, those with DS can benefit from anxiolytic premedication, often with midazolam. If the patient has significant airway obstruction, the dose of sedative premedication should be reduced or withheld. Careful observation of airway and respiratory status after sedation is necessary.

Children with DS are significantly more likely to experience bradycardia during and after sevoflurane induction. Studies indicate that having anticholinergic agents such as atropine available during induction may be prudent, particularly in reducing the copious secretions often present in patients with DS ( ). But with no significant difference in hypotension, pharmacologic interventions, or outcomes, universal prophylactic preinduction administration of atropine is unnecessary ( ).

Induction and maintenance of anesthesia

After ensuring the immediate availability of adjuncts such as oropharyngeal airways, laryngeal mask airways (LMAs), and difficult airway equipment, gentle mask induction may be performed with sevoflurane. Possibly because of their lower sympathetic tone and decreased circulating catecholamines, DS patients are more likely than other children to develop bradycardia during induction and should be monitored closely. This bradycardia is commonly corrected by simply decreasing the concentration of sevoflurane ( ). In one retrospective study, bradycardia with hypotension occurred in 57% of DS patients induced with sevoflurane compared with 12% in a control group. A multivariate analysis demonstrated an association with Down syndrome and low American Society of Anesthesiologists (ASA) physical status with bradycardia. The presence of congenital heart disease was not an independent predictor. Treatment in 24% consisted of an intramuscular or intravascular injection of an anticholinergic. None were administered sympathomimetics ( ).

A gentle jaw thrust may be necessary to maintain airway patency, along with the insertion of an oropharyngeal airway, because of the large tongue, small mouth, midface hypoplasia, floppy epiglottis, and baseline hypotonia. Intubation may be avoided entirely if surgical duration and conditions allow. Because subglottic stenosis is common, careful endotracheal intubation with a tube that is one or two sizes smaller than expected may be required. An LMA may be also be recommended ( ). Care must be taken in passing the tube, and a leak test must be performed to ensure appropriate endotracheal tube (ETT) size. Additionally, special care should be taken at all times during the manipulation of the neck, regardless of a reassuring radiograph. The flexion of the neck carries the greatest risk of subluxation in the presence of atlantoaxial instability. A laryngoscopy with the extension of the head and concomitant lifting of the skull may result in C1–C2 subluxation ( ). Although anesthesia societies have not produced clear guidelines, protection of the cervical spine may be achieved with either manual in-line stabilization, neck collars, or use of video laryngoscopy ( ). Awake extubation minimizes the risk for postoperative airway obstruction.

Postoperative care

Postoperative airway complications are a significant risk in patients with DS ( ). Therefore vigilance must be high, and plans should be in place to recognize and intervene in the event of obstruction. Continuous pulse oximetry, supplemental oxygen, and postanesthesia care unit (PACU) nurses who are well versed in maintaining airway patency are required. Postintubation croup has an average onset of 20 to 30 minutes after ETT removal and may be treated with IV dexamethasone or inhaled racemic epinephrine.

Pain management in the cognitively impaired pediatric patient can be a challenge. Because these patients often have difficulty verbalizing their discomfort, they express pain and discomfort more slowly and localize the stimulus less precisely than other patients ( ). This finding, coupled with a reluctance to administer higher-dose narcotics in a patient population prone to airway obstruction, puts DS patients at risk for inadequate pain therapy. Careful judgment based on objective physiologic parameters (e.g., heart rate, blood pressure), pain scales, and parental input are important for adequate analgesia. Ultrasound-guided peripheral and neuraxial blockade are excellent methods of analgesia that will reduce the need for postoperative narcotics that may cause respiratory depression (see Chapter 23 , Acute Pain Management, and Chapter 24 , Regional Anesthesia). The life expectancy of patients with DS has quadrupled in the last 50 years. Improved access to cardiac surgery and better medical management bring the promise that DS patients will be cared for frequently in the operating suite, providing a unique but rewarding challenge for anesthesia providers.

Antibiotics

Patients who are penicillin allergic may have a reaction if exposed to cephalosporins because of the similarities of the R1 side chain attached to the shared beta-lactam ring ( Fig. 54.2 ). The AAP now states that the likelihood of a cephalosporin allergic reaction is no higher in penicillin-allergic patients as long as the side chains of the two drugs are different ( ). Current recommendations by the American Academy of Allergy on cephalosporin use in the setting of proven penicillin allergy suggest that a convincing history of immunoglobulin E (IgE)–mediated allergy should mandate formal allergy testing and avoidance of the particular antibiotic class ( ). reviewed this topic in detail.