Perioperative anesthetic management of children with congenital central hypoventilation syndrome and rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation undergoing thoracoscopic phrenic nerve-diaphragm pacemaker implantation.

BACKGROUND: Congenital Central Hypoventilation Syndrome and Rapid-Onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation are rare neurocristopathies characterized by autonomic dysregulation including bradyarrhythmias, abnormal temperature control, and most significantly, abnormal control of breathing leading to tracheostomy and ventilator dependence as life support. Surgical advancements have made phrenic nerve-diaphragm pacemakers available, to eliminate the tether to a mechanical ventilator for 12-15 hours each day. The thoracoscopic approach to implantation has allowed for a less invasive approach which may have implications for pain control and recovery time. However, thoracoscopic implantation of these devices presents several challenges to the anesthesiologist in these complex ventilator-dependent patients, including, but not limited to, sequential lung isolation, prevention of hypothermia, and management of arrhythmias. Postoperative challenges may also include strategies to treat hemodynamic instability, managing the ventilator following lung derecruitment, and providing adequate pain control. AIMS: We aimed to describe the anesthetic management of Congenital Central Hypoventilation Syndrome and Rapid-Onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation patients undergoing thoracoscopic phrenic nerve-diaphragm pacemaker implantation and the nature and incidence of perioperative complications. METHODS: A retrospective chart review was performed of 14 children with Congenital Central Hypoventilation Syndrome and Rapid-Onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation undergoing phrenic nerve-diaphragm pacemaker implantation at a single academic pediatric hospital between 2009 and 2017. Demographic information, intraoperative management, and perioperative complications were analyzed from patient records. RESULTS: Twelve of 14 patients (86%) underwent an inhalational induction via tracheostomy. Lung isolation was achieved via fiberoptic guidance of a single lumen endotracheal tube sequentially into the right or left mainstem bronchi for 12 patients (86%). Double lumen endotracheal tubes were utilized in two patients (7%) and bronchial blockers in two patients (7%) for lung isolation. Anesthesia was maintained using a balanced technique of volatile agents (sevoflurane/isoflurane) and opioids (fentanyl). Bradyarrhythmias developed in six patients (43%) during surgery, 5 (36%) responded to anticholinergics and one patient (7%) required backup cardiac pacing using a previously implanted bipolar cardiac pacemaker. Intraoperative hypothermia (<35.5°C) was present in five patients (36%) despite the use of warming devices. Hypercarbia (>50 mm Hg) during lung isolation was present in eight patients (57%) and hemoglobin desaturation (<90%) in four patients (29%). Postoperatively, oxygen desaturation was a common complication with nine patients (64%) requiring supplemental oxygen administration via mechanical ventilator or manual bag ventilation. Opioids via patient-controlled analgesia devices (12 patients, 86%) or intermittent injection (two patients, 14%) were administered to all patients for postoperative pain control. Phrenic nerve-diaphragm pacemaker placement was successful thoracoscopically in all patients with no perioperative mortality. CONCLUSION: The main anesthetic challenges in patients with Congenital Central Hypoventilation Syndrome and Rapid-Onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation include hemodynamic instability, the propensity to develop hypothermia, hypercarbia/hypoxemia, and the need to perform bilateral sequential lung isolation requisite to the thoracoscopic implantation technique. Most anesthetic agents can be used safely in these patients; however, adequate knowledge of the susceptibility to complications, coupled with adequate preparation and understanding of the innate disease characteristics, are necessary to treat anticipated complications.

Comparison of laryngeal mask airway insertion methods, including the external larynx lift with pre-inflated cuff, on postoperative pharyngolaryngeal complications: A randomised clinical trial.

BACKGROUND: Postoperative pharyngolaryngeal complications are commonly reported following laryngeal mask airway (LMA) insertion. After induction of anaesthesia, the airway structures fall backwards under the influence of gravity, and this may contribute to difficulty in placement of a LMA. External airway alignment by lifting the larynx during insertion of an airway may avoid collision of the airway with laryngeal structures. OBJECTIVE(S): To compare pharyngolaryngeal complications after either conventional airway insertion with or without cuff semi-inflation and a method, including an external larynx lift. DESIGN: Randomised controlled, double-blind, clinical trial. SETTING: Ambulatory surgical operating rooms of a university hospital. PATIENTS: American Society of Anaesthesiologists class 1 to 3 patients undergoing ambulatory surgery scheduled to receive general anaesthesia for which a LMA was not contraindicated. INTERVENTIONS: Patients were randomised into three groups for LMA placement: G1, deflated airway; G2, pre-inflated cuff; G3, pre-inflated cuff with external lifting of the larynx. Assessment of pharyngolaryngeal complications (blinded assessor) was made at the time of LMA removal and again at 1, 2 and 24 h. MAIN OUTCOME MEASURES: A pharyngolaryngeal complication, defined as a composite of one or more of sore throat, dysphonia or dysphagia at any time point, or blood on the airway at removal. RESULTS: Of the 450 consecutive patients, 441 were studied. There were no differences in insertion times or number of insertion attempts among the groups. There was no difference in pharyngolaryngeal complications among the groups: G1, 57%; G2, 55%; G3, 52%, (P = 0.77). Blood on the airway was observed less frequently in G3 (9%) compared with G1 and G2 combined (17%): difference -8% (95% confidence interval of the difference -0.8 to -16%, P = 0.01). CONCLUSION: The external larynx lift technique was associated with a lower incidence of blood on the airway at removal, suggesting that the method may decrease trauma to the tissues of the upper airway during insertion. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01749033.