Anesthesia for the child with an inhaled foreign body

INTRODUCTION — Tracheobronchial foreign body aspiration (FBA) is a common cause of morbidity and mortality in young children. Children with known or suspected FBA may require rigid or flexible bronchoscopy, or rarely thoracotomy, for removal of foreign bodies.

This topic will discuss anesthetic management of bronchoscopy for FBA in children. Epidemiology, presentation, evaluation, and management of FBA in children are discussed separately, as well as anesthesia for bronchoscopy in adults. (See "Airway foreign bodies in children" and "Anesthesia for adult bronchoscopy".)

PREANESTHESIA EVALUATION — The usual preanesthesia evaluation should be performed whenever possible, including a history and anesthesia-directed physical examination. (See "General anesthesia in neonates and children: Agents and techniques", section on 'Preoperative evaluation'.)

Children in respiratory distress, or with suspected laryngeal or tracheal foreign body aspiration (FBA) should be taken urgently to the operating room for bronchoscopy. For other children, the timing of the bronchoscopy should be discussed with the surgeon. For children who are stable and at low risk of progression of airway obstruction, the procedure may be scheduled during optimal operating room staffing conditions [1] and after routine preoperative fasting (ie, six hours for solid foods, one hour for clear liquids) to minimize the risk of aspiration on induction of anesthesia. (See "Preoperative fasting in children and infants".)

Full stomach concerns should not delay procedures for children thought to be at risk of progression of airway obstruction. Aspiration of stomach contents has not been reported in large series of children with FBA, whereas there are multiple reports of progression from partial to complete airway obstruction, from movement or swelling of the foreign body, or swelling of the tracheobronchial mucosa [2-5]. For patients with full stomachs, a large bore gastric tube can be placed and suctioned after induction of anesthesia to reduce the volume of stomach contents.

Inhaled foreign bodies may cause pneumonia, atelectasis, hyperinflation distal to the obstruction, and/or bronchospasm, which may affect anesthetic management. Most children will come to the operating room after evaluation that has determined the location of the foreign body, timing of aspiration, and type of foreign body (algorithm 1). (See "Airway foreign bodies in children", section on 'Suspected foreign body aspiration'.)

These issues, as well as the plan for rigid or flexible bronchoscopy, the mode of ventilation during maintenance of anesthesia, and the need for neuromuscular blockade, should be discussed with the surgeon to plan the anesthetic. For any surgery, and particularly for procedures in which the airway is used by both the surgical and anesthesia teams, excellent, closed-loop communication and in-depth pre-planning for both anesthesia and surgery are warranted to maximize patient safety.

OPERATING ROOM TEAM PREPARATION — In addition to the usual preparation for anesthesia, the bronchoscopist should be present in the operating room, with the equipment necessary for emergency airway rescue, prior to induction of anesthesia. All operating room nursing and technician staff should be part of the pre-procedure planning process.

ANESTHESIA FOR RIGID BRONCHOSCOPY — Rigid bronchoscopy is the procedure of choice for foreign body removal. (See "Airway foreign bodies in children", section on 'Bronchoscopy'.)

General anesthesia is required for children who undergo rigid bronchoscopy.

Premedication — Premedication for children with foreign body aspiration (FBA) should be administered as it would be for other children who undergo anesthesia. We routinely premedicate pediatric patients with intravenous midazolam to facilitate separation from parents or caregivers and transfer into the operating room suite for the procedure. (See "General anesthesia in neonates and children: Agents and techniques", section on 'Patient and parent or caregiver preparation for anesthesia'.)

Monitoring and intravenous access — The basic physiologic monitoring modalities used for adults during anesthesia are used for children as well, with appropriately sized equipment. (See "General anesthesia in neonates and children: Agents and techniques", section on 'Monitoring'.)

Unless an intravenous catheter is already in place, the decision to place one before or after induction of general anesthesia depends on the patient's age and the clinical scenario. (See "General anesthesia in neonates and children: Agents and techniques", section on 'Choice of induction technique'.)

Induction of anesthesia for rigid bronchoscopy — Whether an inhaled or intravenous induction is performed, the goal should be to maintain spontaneous ventilation, particularly for children with proximal (ie, laryngeal or tracheal) FBA. The use of positive pressure ventilation may theoretically move a foreign body in the tracheobronchial tree and convert a partial obstruction to a complete obstruction. Avoidance of positive pressure ventilation is less important if the foreign body is located distally in the bronchus.

We routinely perform an inhalation induction with 100 percent oxygen and sevoflurane and maintain spontaneous ventilation during induction. After induction, the bronchoscopist sprays the vocal cords and trachea with 1 or 2% lidocaine, often only 2 to 3 mL total volume, limited by weight-based maximum doses (ie, 4 to 5 mg/kg without epinephrine, 5 to 7 mg/kg with epinephrine).

Maintenance of anesthesia — Patients require deep general anesthesia to tolerate rigid bronchoscopy. The decisions to employ an intravenous versus an inhaled technique, to administer neuromuscular blocking agents (NMBAs), and to use intermittent positive pressure ventilation, spontaneous ventilation, or jet ventilation should be discussed with the bronchoscopist. The optimal choice of anesthetic agents and mode of ventilation are debated among pediatric anesthesiologists, and practice varies.

Choice of anesthetic agents — Inhalation anesthesia, intravenous anesthesia, or a combination of the two can be used for bronchoscopy for foreign body retrieval. The author routinely uses a combination of inhaled sevoflurane, intravenous propofol (either as a continuous infusion or administered as boluses as needed), and intravenous dexmedetomidine (either as a continuous infusion or administered as an upfront bolus) for induction and maintenance of anesthesia. Others add a remifentanil infusion to help the patient tolerate the rigid bronchoscope; remifentanil may be particularly useful in this setting because of its rapid onset and offset. (See "General anesthesia in neonates and children: Agents and techniques", section on 'Intravenous induction medications'.)

We avoid NMBAs unless required urgently.

Considerations when choosing anesthetic agents for rigid bronchoscopy include the following:

●Maintaining an adequate depth of anesthesia may be difficult with inhaled anesthetics (ie, sevoflurane, isoflurane, or halothane) because of intermittent interruption of ventilation and leak around the bronchoscope. Inhalation anesthesia during rigid bronchoscopy also pollutes the operating room with anesthetic gases.

●Total intravenous anesthesia (TIVA) allows for a continuous level of anesthesia regardless of ventilation, but can also more easily abolish spontaneous ventilation. TIVA is usually administered with NMBAs and controlled ventilation. In one study, TIVA administered with spontaneous ventilation (without NMBAs) was associated with increased movement, breath holding, and laryngospasm, compared with inhalation anesthesia [6]. (See "General anesthesia in neonates and children: Agents and techniques", section on 'Maintenance of anesthesia'.)

●The combination of inhalation anesthesia with intravenous agents helps achieve a more stable, adequate depth of anesthesia than inhalation agents alone, while allowing spontaneous ventilation.

Oxygenation — Supplemental oxygen can be administered via nasal canula or through an oral RAE tube placed in the corner of the mouth, during spontaneous ventilation or during apneic oxygenation. We find that supplemental oxygen delivered by simple nasal canula is less noisy and distracting for clinicians than humidified high flow nasal canula and provides plenty of oxygen reserve during airway manipulation and bronchoscopy [7]. Options for apneic oxygenation in children are discussed separately. (See "Management of the difficult airway for pediatric anesthesia", section on 'Apneic oxygenation'.)

Mode of ventilation during rigid bronchoscopy — The plan for ventilation during the procedure should be discussed preoperatively with the bronchoscopist. The discussion should include the possible need for changes during the procedure as dictated by the clinical conditions. In one small study of children who underwent rigid bronchoscopy for FBA, 36 children were randomly assigned to either spontaneous ventilation or controlled ventilation with paralysis during halothane anesthesia [8]. All 17 children in the spontaneous ventilation group required conversion to assisted ventilation because of oxygen desaturation or inadequate depth of anesthesia. In practice, the choice between spontaneous and controlled ventilation is often one of personal preference, and does not usually affect the outcome of the procedure.

Spontaneous ventilation during the maintenance of anesthesia minimizes the chance that an unstable foreign body will be moved more distally, and negative pressure (spontaneous) ventilation can theoretically allow for better oxygenation and ventilation for some obstructive lesions [9]. The ability to ventilate with positive pressure around an airway obstruction is not guaranteed, even with a ventilating bronchoscope.

In most cases of foreign body retrieval, a ventilating rigid bronchoscope is used, which provides the option to attempt positive pressure ventilation through the ventilating port when needed due to the hypoventilation that occurs at the required depth of anesthesia or as a result of administration of neuromuscular blocking agents (NMBAs). If a non-ventilating bronchoscope is used, intermittent mask ventilation is an option.

Emergence from anesthesia — Once the foreign body and the bronchoscope are removed, airway secretions should be suctioned while the child is still deeply anesthetized to minimize the chance of laryngospasm. The technique for emergence is driven largely by the state of pulmonary gas exchange and the amount of airway edema. For uncomplicated procedures without airway edema, we prefer to allow the child to emerge without an airway device in place, with oxygen administered by face mask. Patients with airway edema, persistent oxygen desaturation, or residual neuromuscular blockade may require endotracheal intubation and delayed emergence or recovery in the intensive care unit.

POSTOPERATIVE MANAGEMENT — Most patients who undergo uncomplicated removal soon after aspiration of a foreign body are discharged from the hospital within four hours of bronchoscopy [10]. Patients who require lengthy bronchoscopy or develop complications, including airway trauma, pneumonia, atelectasis, pneumothorax or pneumomediastinum, or who require postoperative oxygen supplementation may require admission to the hospital and/or intensive care unit for further treatment [11].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Airway foreign bodies in children" and "Society guideline links: Pediatric anesthesia".)

SUMMARY AND RECOMMENDATIONS

●Timing of bronchoscopy – Children in respiratory distress or with suspected laryngeal or tracheal foreign body aspiration (FBA) should be taken urgently to the operating room for bronchoscopy. Timing of bronchoscopy for other children should be discussed with the bronchoscopist (algorithm 1) (see 'Preanesthesia evaluation' above):

•For children with low risk of progression of airway obstruction, bronchoscopy may be performed during optimal operating room staffing hours and after appropriate fasting.

•Full stomach concerns should not delay procedures for children thought to be at risk of progression of airway obstruction.

●Preoperative evaluation – The location of the foreign body, associated complications (eg, pneumonia, atelectasis, bronchospasm), planned procedure, and requirements for management of ventilation should be discussed with the bronchoscopist preoperatively. (See 'Preanesthesia evaluation' above.)

●Anesthetic management – General anesthesia is required for children who undergo rigid bronchoscopy. Rigid bronchoscopy is the procedure of choice for foreign body removal. (See 'Anesthesia for rigid bronchoscopy' above.)

•During induction of anesthesia, the goal should be to maintain spontaneous ventilation, particularly for children with proximal (ie, laryngeal or tracheal) FBA. Avoidance of positive pressure ventilation is less important if the foreign body is located distally in the bronchus. (See 'Induction of anesthesia for rigid bronchoscopy' above.)

•Patients require deep general anesthesia to tolerate rigid bronchoscopy. The author routinely administers a combination of inhaled sevoflurane, intravenous propofol, and intravenous dexmedetomidine for maintenance of anesthesia for rigid bronchoscopy for FBA. (See 'Choice of anesthetic agents' above.)

•Spontaneous ventilation during bronchoscopy may minimize the chance that an unstable foreign body will move distally and obstruct the airway. However, positive pressure ventilation may be required either because of hypoventilation at the required depth of anesthesia or because of administration of neuromuscular blocking agents (NMBAs). (See 'Mode of ventilation during rigid bronchoscopy' above.)

●Emergence from anesthesia – For uncomplicated procedures, we prefer to allow the patient to emerge from anesthesia with oxygen administered by face mask. Patients with airway edema, oxygen desaturation, or residual neuromuscular blockade may require endotracheal intubation and delayed emergence. (See 'Emergence from anesthesia' above.)