What are the appropriate anesthesia, medication, and pain management strategies for a 7-year-old patient (20kg) undergoing orthopedic casting of both lower limbs, who experiences bronchospasm (co thắt phế quản), tachycardia (mạch nhanh), and stable blood pressure during the procedure?

From the Guidelines

For a 7-year-old, 20kg patient undergoing orthopedic casting of both lower limbs, intravenous anesthesia with Ketamine is recommended, along with preoperative administration of inhaled salbutamol to mitigate the risk of bronchospasm. The typical dose for Ketamine in children is 1-2 mg/kg IV 1. Given the patient's weight, the dose would be 20-40mg of Ketamine.

Anesthesia and Bronchospasm Management

• The choice of anesthesia should prioritize the patient's safety and comfort, considering their history of bronchospasm and tachycardia.
• Inhaled salbutamol (2.5mg) should be administered preoperatively to reduce the risk of perioperative bronchospasm, as recommended by the French guidelines for pediatric anesthesia 1.
• If bronchospasm occurs during the procedure, use Ventolin (salbutamol) inhaler, 2-4 puffs via spacer device, as it is the first-line treatment for acute bronchospasm due to its rapid onset of action.

Post-Procedure Pain Management

• Post-procedure pain should be managed with Paracetamol, either orally (15 mg/kg every 4-6 hours) or rectally (20 mg/kg every 4-6 hours), as recommended by the European Society for Paediatric Anaesthesiology (ESPA) pain management ladder initiative 1.
• Paracetamol is safe and effective for post-procedure pain in children, avoiding the risks associated with opioids or invasive pain management techniques.
• The use of NSAIDs or metamizole may also be considered, but Paracetamol is generally the preferred first-line treatment for mild to moderate pain in children.

Key Considerations

• Ketamine is preferred over Propofol in children due to its analgesic properties and cardiovascular stability 1.
• The patient's stable blood pressure and tachycardia should be closely monitored during the procedure, and the anesthetic plan should be adjusted accordingly.
• The use of a facemask is associated with less perioperative respiratory adverse events in children with an upper respiratory tract infection, but the choice of airway device ultimately depends on multiple factors, including the type and duration of surgery 1.

From the FDA Drug Label

Pediatric Patients Most patients aged 3 years through 16 years and classified ASA-PS I or II require 2.5 mg/kg to 3. 5 mg/kg of propofol injectable emulsion for induction when unpremedicated or when lightly premedicated with oral benzodiazepines or intramuscular opioids. A lower dosage is recommended for pediatric patients classified as ASA-PS III or IV Changes in vital signs indicating a stress response to surgical stimulation or the emergence from anesthesia may be controlled by the administration of 25 mg (2. 5 mL) to 50 mg (5 mL) incremental boluses and/or by increasing the infusion rate of propofol injectable emulsion.

For a 7-year-old patient (20kg) undergoing orthopedic casting of both lower limbs, who experiences bronchospasm, tachycardia, and stable blood pressure during the procedure, the appropriate anesthesia and medication strategy would be to:

• Use a lower dosage of propofol injectable emulsion for induction, considering the patient's age and potential ASA-PS classification.
• Administer incremental boluses of 25 mg (2.5 mL) to 50 mg (5 mL) and/or increase the infusion rate of propofol injectable emulsion to control changes in vital signs indicating a stress response to surgical stimulation.
• Consider using other medications, such as anticholinergic agents, to manage potential increases in vagal tone.
• Monitor closely for cardiorespiratory depression, apnea, and airway obstruction, especially following rapid bolus administration.
• Use slow infusion or slow injection techniques for MAC sedation to minimize undesirable cardiorespiratory effects.
• Consider premedication with opioids, such as morphine, to decrease the necessary propofol injectable emulsion maintenance infusion rates and therapeutic blood concentrations 2.
• Titrate downward the infusion rate of propofol injectable emulsion in the absence of clinical signs of light anesthesia to avoid administration at rates higher than clinically necessary 2.

From the Research

Anesthesia and Medication Strategies

• For a 7-year-old patient undergoing orthopedic casting of both lower limbs, propofol can be used for intraoperative sedation, as it is a popular agent for providing sedation in pediatric populations during procedures like lumbar puncture and spinal anesthesia 3.
• Clonidine can be used as an adjuvant to provide postoperative analgesia with a local anesthetic agent, and it has been shown to reduce the requirements of propofol sedation whether administered intravenously or intrathecally 3.
• Another option for brief orthopedic procedural sedation is the use of propofol/fentanyl (P/F) or ketamine/midazolam (K/M), with P/F offering a quicker offset and smoother recovery profile, although it has a greater potential for respiratory depression and airway obstruction 4.

Pain Management Strategies

• The use of regional anesthesia, such as peripheral nerve blocks, has increased over time for children undergoing ambulatory orthopedic procedures, and it can be performed in conjunction with general anesthesia 5.
• The choice of anesthesia and pain management strategy should take into account the patient's medical history, including conditions such as bronchospasm and tachycardia, and stable blood pressure during the procedure.
• It is essential to monitor the patient's vital signs and adjust the anesthesia and pain management strategy as needed to ensure the patient's safety and comfort during the procedure.

Considerations for Orthopedic Casting

• When applying a cast, it is recommended to use cotton padding for the liner and fiberglass or plaster, depending on the expected swelling, and to ensure a well-molded cast to prevent further fracture displacement 6.
• Cast valving is a valuable technique to decrease pressure and prevent discomfort and complications like compartment syndrome, and patient education is crucial for proper cast maintenance 6.