Continuing Education Activity

Babies born with Pierre- Robin sequence commonly present with respiratory distress and feeding difficulties due to mandibular hypoplasia and posteriorly placed tongue. The associated cleft palate leads to recurrent upper respiratory tract and ear infections. These patients will require various surgical interventions to correct the anatomical abnormalities and other related defects. This activity outlines the evaluation and management of the Pierre- Robin sequence and highlights the role of the inter-professional team in managing patients with this condition.

Objectives:

• Outline the anesthetic management considerations for patients with Pierre- Robin sequence.

• Summarize the anticipated complications during the intraoperative and postoperative period among patients with Pierre-Robin sequence.

• Describe the common intubation methods before administering general anesthesia among patients with Pierre- Robin sequence.

• Explain the importance of monitoring patients with Pierre- Robin Sequence after extubation in the post-anesthesia care unit.

Introduction

Pierre Robin sequence (PRS) is a triad of micrognathia, posterior-inferior displacement of the tongue base (glossoptosis), and airway obstruction.[1] PRS affects approximately up to 1 in 14,000 newborns a year. PPRS can occur in isolation but is more often associated with other syndromes such as Fetal alcohol syndrome, Stickler syndrome, velocardiofacial syndrome, and Treacher-Collins syndrome.[2][3] At birth, neonates mainly exhibit signs of respiratory distress (stridor, retractions, and cyanosis); some manifest with feeding difficulty, gastroesophageal reflux, aspiration, and failure to thrive.[4][5]

A sequence is a pattern of congenital anomalies that result from a single defect during development. In PRS, micrognathia is the single initiating event that occurs during development. It results in a cascade of secondary defects such as glossoptosis and cleft palate. The abnormal mandible displaces the tongue into the nasopharynx, thus preventing the fusion of palatal shelves. This gives rise to varying severity of cleft palate. In addition to cleft palate, glossoptosis also gives rise to airway obstruction and obstructive sleep apnea if severe.[6]

In approximately 70% of cases of PRS, placing the neonate in a prone or lateral position relieves airway obstruction, but if the neonate desaturates, then a nasopharyngeal (NP) tube can be placed to bypass upper airway obstruction.[7][8] Patients with mild airway obstruction managed conservatively are at risk for failure to thrive due to feeding difficulties, gastroesophageal reflux, and aspiration. In such cases placing a gastrostomy tube until they achieve catch-up growth may help prevent the above complications. In acute severe airway obstruction, the patient must undergo an emergent tracheostomy to bypass the compromised airway.[9]

After initial stabilization of the patient, procedures such as tongue lip adhesion and mandibular distraction osteogenesis can correct glossoptosis, lengthen the mandible and relieve glossoptosis. Also, the above techniques may need to be performed in conservatively managed PRS who fail to achieve an adequate catch-up growth.[10][11] Patients often require palatoplasty to correct the palatal defect, fix feeding difficulties, and facilitate normal speech development.

The above-listed procedures require anesthetic intervention in the form of general anesthesia. Anesthesiology-assisted sedation may be needed in patients undergoing magnetic resonance imaging (MRI) and computed tomography (CT).

Issues of Concern

Pierre-Robin sequence (PRS) poses numerous challenges to anesthesiologists. 

1. The airway is challenging to ventilate and intubate due to craniofacial dysmorphology in patients with PRS. Maintaining a seal for ventilation using a facemask can be challenging due to facial deformities. Direct laryngoscopy and tracheal intubation tend to be very difficult during infancy but generally become more manageable with age and (mandibular) growth.
2. Post-operatively, PRS patients can develop spontaneous airway collapse. It may occur due to pre-existing airway obstruction, possible Obstructive Sleep Apnea, chronic hypoxia, and increased opioid sensitivity. It can be diagnosed with paradoxical breathing patterns, intercostal indrawing, subcostal, sternal recession, and tracheal tug.[12]
3. Neonates with PRS are increasingly sensitive to opioids- Infants who develop OSA due to glossoptosis have escalated opioid sensitivity due to the upregulation of opioid receptors in the brainstem. Patients with severe obstruction have significantly fewer opioid requirements and careful dose adjustments.[13]
4. Feeding difficulties, swallowing disorders, and co-existing gastroesophageal reflux are frequently complicated by bronchial microaspirations and pulmonary infections.[14] Therefore, aspiration precautions should be implemented before elective procedures.
5. PRS patients are generally malnourished and have a high frequency of failure to thrive due to difficulties with feeding and airway.[15]

Clinical Significance

Pre-anesthetic Assessment

Neonates/infants presenting with PRS present significant challenges to anesthesia providers in intraoperative and postoperative periods, especially with airway management. Preoperatively, anesthesiologists should obtain a detailed history of the patient's symptoms, including recent upper respiratory infections, features suggestive of reflux and aspiration, and details of the previous anesthetic intervention.

A detailed physical examination emphasizing airway evaluation and cardio-pulmonary examination is imperative to formulate an appropriate anesthetic management plan. Airway evaluation should include assessing the mouth opening, presence of cleft palate, degree of airway obstruction, the severity of micrognathia, presence of other craniofacial skeletal abnormalities. In addition, it is crucial to identify patients with features of OSA as it helps to predict intraoperative and postoperative airway complications and those who do not tolerate supine positioning. Physical examination should include oxygen saturation at room air in addition to heart rate, respiratory rate, and blood pressure.

Preoperative workup should encompass complete blood counts and other tests depending on comorbidities present, including serum electrolytes, renal function tests, video laryngoscopy, chest X-ray, and computed tomography (CT). If PRS is associated with other syndromes, a preoperative echocardiogram should be performed, especially in the presence of a murmur.[16]

Induction and Airway Management

Anesthesia providers should anticipate difficulty with ventilation, oxygenation, and intubation. Intubation can be performed with or without sedation and general anesthesia. The main objective of managing the anticipated difficult pediatric airway should be to maintain spontaneous ventilation under sedation or general anesthesia. Upper airway obstruction is very common in syndromic children and can be relieved with 2-handed jaw thrust and airway adjuncts like oropharyngeal airway, nasopharyngeal airway, or laryngeal mask airway (LMA). Otorhinolaryngology (ENT) surgeons should be available for emergency tracheostomy or bronchoscopy.

Several techniques have been described to secure the airway in Pierre Robin patients, including Laryngeal Mask Airway, fiberoptic scope, retrograde wire, and other proprietary intubation devices. While using direct laryngoscopy to intubate, the right paraglossal approach is found to be more effective than the standard technique. However, this approach makes passing an endotracheal tube more challenging, and a bougie may be required to aid intubation.[16] For tongue-lip adhesion and Mandibular distraction osteogenesis, general practice is to use nasal intubation. Awake fiberoptic intubation is more traditional; however, mask induction with asleep intubation with patient breathing spontaneously can be performed as well.

For awake fibreoptic intubation in neonates, intravenous access is obtained ideally before induction. The pharynx and oral cavity are anesthetized using topical lidocaine (2%) atomizer and jelly. The dose of lidocaine should be limited to 4 or 5 mg/kg. A vagolytic (atropine/glycopyrrolate) is administered to prevent bradycardia and as an anti-sialogogue. If intubating orally, an intubating supraglottic device may be helpful. On visualizing the vocal cords, an intravenous induction agent can be administered. A neuromuscular blocking agent is administered prior to passing the scope through the vocal cords to avoid laryngospasm. 

Anesthesia can be induced with both volatile and intravenous anesthetic agents like propofol. Sevoflurane is the most commonly used volatile agent in pediatric practice and is recommended to manage a difficult airway. Isoflurane can also be used as an alternative. Desflurane should be avoided in patients with bronchial hyperreactivity as it can cause laryngospasm, coughing, and increased secretions. 

In addition to inhalational agents, anesthesia can be maintained with opioids and alpha-2 agonists such as clonidine or dexmedetomidine, which may reduce opioid requirements and have analgesic and sedative properties. It can also reduce the incidence of emergence agitation.[17] Ketamine causes minimal respiratory depression by maintaining a near-normal ventilatory response to carbon dioxide; therefore, ketamine is preferred for procedures performed under sedation. Ketamine causes bronchodilation and counteracts intubation-induced bronchospasm. However, ketamine increases airway secretions, so anti-sialogogues should be administered as prophylaxis before using it.

Dexmedetomidine is a centrally acting alpha-2 receptor agonist which decreases the central sympathetic outflow. An exceptional characteristic of dexmedetomidine is the preservation of respiratory drive. It is associated with a low rate of occurrence of apnea, respiratory depression, and airway obstruction. Dexmedetomidine is highly favorable in children prone to airway collapse or respiratory depression. These features of dexmedetomidine, combined with a short half-life, make it a helpful sedative agent for ambulatory pediatric procedures (CT/ MRI).[18]

Intraoperative monitoring should include neuromuscular monitoring, rectal/ nasal temperature in addition to an electrocardiogram (EKG), non-invasive blood pressure (NIBP), end-tidal carbon dioxide (ETCO2), pulse oximetry. Complete reversal of neuromuscular block with monitoring and awake extubation should be conducted. A nasopharyngeal airway can be inserted before extubation to prevent postoperative airway obstruction. 

Patients with PRS have preexisting airway obstruction, obstructive sleep apnea (OSA), chronic hypoxia, and increased opioid sensitivity making them increasingly prone to develop postoperative respiratory complications. Prolonged surgical duration and pressure exerted on the base of the tongue by retractors and airway edema may worsen the preexisting obstruction.[19] The development of postoperative complications can be minimized by performing neck extension and jaw-thrust alone or using nasopharyngeal/ oropharyngeal airways. Post-operatively, nursing the child in a lateral position with neck extended can also reduce the possible complications.[12] To prevent postoperative respiratory obstruction, non-opioid analgesics, regional blocks, and local infiltration should be considered.

Enhancing Healthcare Team Outcomes

Infants born with Pierre Robin Sequence are at risk of developing airway-related complications, hypoxia, cor-pulmonale, and failure to thrive. Active multidisciplinary management of such infants is indispensable to reduce the complications of neurocognitive impairment secondary to the associated malformations. 

The preparation of a neonate/ infant who is scheduled to undergo surgery or anesthesia should involve the child's family, pediatrician, anesthesiologist, plastic surgeon, and other specialists caring for the child. Conveying relevant information among the individuals caring for the patient is vital to ensure a pleasant perioperative course. Pre-operatively, involving the nursing staff to provide appropriate feeding techniques to ensure adequate hydration and nutrition will reduce the incidence of regurgitations, aspiration and will improve growth and development. 

Shared decision-making involving the interprofessional provider team may prevent unnecessary surgeries and complications post-surgery. In addition, shared decision-making would allow them to determine the best possible management plan for the PRS patient. To establish a culture of patient safety and safe medication handling in the operation room and post-anesthesia care unit, the involvement of pharmacists is critical. Pharmacists should be involved in analyzing adequate dose adjustments in neonates, dosing frequencies, especially opioids and anti-emetics. Pharmacists can also be a part of educational activities and alert anesthesia providers about changes in labels or concentrations of anesthetic medications.[20]

Close postoperative monitoring of the PRS patients in the Post Anesthesia Care Unit (PACU) by the nursing staff and anesthesia providers can lead to early recognition of post-op complications, and early interventions will prevent catastrophes. Nursing professionals also play a critical role in helping neonate's parents/ family verbalize their concerns and prepare them to care for the baby appropriately. They can provide reassurance, reduce their anxiety and promote coping. Thus, a multidisciplinary team approach can enhance patient-centered care, improve outcomes, patient safety, and improve team performance.

Various aspects of teamwork to improve patient outcomes and safety include:

1. Adopting a quality collaboration by showing mutual respect and trust.
2. Developing shared goals, perception of a situation, and understanding of tasks and roles within the team.
3. Adaptive coordination allocates tasks for new team members, facilitates information exchange and planning in critical situations, and exhibits openness and excellent communication quality.
4. Practicing specific communication practices such as team briefing.
5. Leadership that encourages the participation of team members in the decision-making process and increases explicit leadership behavior in critical situations.[21] [Level 5]