Overview
Definition:
Procedural sedation and analgesia (PSA) is the administration of medications to depress a patient's central nervous system to allow for a procedure to be performed, while maintaining the patient's cardiorespiratory function
It aims to provide amnesia, anxiolysis, analgesia, and immobility
In pediatrics, PSA is critical for reducing patient distress during common medical and surgical interventions.
Epidemiology:
PSA is widely used across various pediatric settings, including emergency departments, radiology suites, and procedural areas
While specific incidence data varies by procedure and institution, it is estimated that millions of pediatric procedures are performed annually requiring sedation
Complication rates are generally low when appropriate guidelines are followed.
Clinical Significance:
Appropriate fasting guidelines and effective airway risk stratification are paramount for ensuring patient safety during pediatric procedural sedation
Inadequate fasting increases the risk of aspiration, a potentially life-threatening complication
Conversely, overly restrictive fasting can lead to hypoglycemia and dehydration
Understanding airway anatomy and potential challenges allows for proactive management and prevention of respiratory emergencies.
Fasting Guidelines
Rationale:
Fasting prior to sedation reduces the volume and acidity of gastric contents, thereby minimizing the risk of aspiration pneumonitis
Current guidelines are evidence-based and aim to balance safety with patient comfort and physiological needs.
Recommendations:
For clear liquids (e.g., water, clear fruit juices without pulp, electrolyte solutions): 2 hours prior to elective procedures
For breast milk: 4 hours prior to elective procedures
For infant formula and light meals (e.g., toast, crackers): 6 hours prior to elective procedures
For heavy meals (e.g., fried foods, fatty foods, meats): 8 hours prior to elective procedures
These are general guidelines and may be modified based on patient-specific factors and the nature of the procedure.
Exceptions And Modifications:
In emergency situations, fasting guidelines may be waived or modified
Patients with specific medical conditions (e.g., gastroesophageal reflux disease, delayed gastric emptying) may require individualized fasting protocols
The decision to proceed with or without adequate fasting must be made by a qualified clinician after careful risk-benefit assessment.
Special Populations:
Neonates and infants younger than 3 months have different gastric emptying times and are at higher risk for hypoglycemia
these factors should be considered
Patients with metabolic disorders or those receiving certain medications may also require adjustments.
Airway Risk Stratification
Importance:
Pediatric airway management is challenging due to anatomical differences (smaller diameter, higher larynx, more anterior larynx, larger occiput, prominent adenoids/tonsils) and physiological immaturity
Stratifying risk allows for tailored preparation and appropriate equipment selection.
Risk Factors:
Factors increasing airway risk include: age < 1 year
prematurity
known difficult airway (e.g., craniofacial anomalies, syndromes like Down syndrome, Pierre Robin sequence)
obesity
upper respiratory tract infection
obstructive sleep apnea
tonsillar hypertrophy
foreign body in airway
conditions associated with increased secretions (e.g., cerebral palsy)
urgent/emergent procedures
Patients with increased secretions or a propensity for laryngospasm also pose a higher risk.
Assessment Tools:
While formal scoring systems are less standardized in pediatrics compared to adults, a systematic assessment should include: evaluation of facial structure for anomalies
assessment of mouth opening and thyromental distance (though less reliable in young infants)
presence of loose teeth
assessment of neck mobility
history of stridor or obstructive breathing
recent upper respiratory infection symptoms
The LEMON criteria, adapted for pediatrics, can be useful (Look externally, Evaluate 3-3-2 rule, Mallampati score, Obstruction, Neck mobility).
Preparedness:
Based on risk stratification, ensure availability of appropriate airway equipment: various sizes of endotracheal tubes, nasopharyngeal and oropharyngeal airways, laryngoscope blades (straight and curved), stylets, suction catheters, bag-valve-mask (BVM) devices, and emergency medications
Advanced airway management equipment (e.g., video laryngoscope, supraglottic airway devices) should be readily accessible for higher-risk patients or anticipated difficult airways.
Sedation Agents And Protocols
Common Agents:
Agents commonly used in pediatric procedural sedation include: Midazolam (benzodiazepine for anxiolysis and amnesia), Fentanyl or other opioids (for analgesia), Ketamine (dissociative anesthetic with analgesic and bronchodilator properties), Propofol (short-acting hypnotic), Nitrous oxide (inhalational agent for mild sedation and analgesia).
Selection Criteria:
Agent selection depends on the procedure type, patient age and comorbidities, desired level of sedation/analgesia, and the clinician's experience
For painful procedures, a combination of an analgesic and an anxiolytic is often preferred
For non-painful procedures like imaging, an anxiolytic or hypnotic may suffice.
Monitoring Parameters:
Continuous monitoring is essential and includes: heart rate, respiratory rate, blood pressure, oxygen saturation (SpO2), end-tidal carbon dioxide (if available), and level of consciousness/responsiveness
Visual assessment of chest rise and air entry is critical.
Equipment Considerations:
Appropriate monitoring equipment for pediatric patients must be available, including pediatric-sized blood pressure cuffs, pulse oximeter probes, and capnography sensors
Emergency resuscitation equipment and medications must be immediately accessible.
Management Of Respiratory Complications
Hypoxemia:
Management of hypoxemia involves ensuring a patent airway, providing supplemental oxygen, and using bag-valve-mask ventilation if spontaneous breathing is inadequate
Advanced airway interventions may be necessary.
Apnea And Hypoventilation:
These are managed by stimulation, airway repositioning, assisted ventilation with BVM, and potential administration of respiratory stimulants (though this is less common and generally not recommended as a first-line approach).
Laryngospasm:
Treatment involves positive pressure ventilation with 100% oxygen
If unsuccessful, a small dose of succinylcholine (if intubation is not contraindicated) or deepening the anesthetic may be considered to break the spasm
Epinephrine can also be used.
Bronchospasm:
Requires administration of inhaled bronchodilators (e.g., albuterol) and, if severe, systemic corticosteroids
The choice of sedation agent should also be reviewed as some agents can exacerbate bronchospasm.
Key Points
Exam Focus:
Understanding the age-specific fasting guidelines for clear liquids, breast milk, and formula is crucial
Recognition of pediatric airway anatomy variations and factors predisposing to difficult intubation/airway management is high-yield
Knowing the primary indications and contraindications for common pediatric sedation agents.
Clinical Pearls:
Always have age-appropriate airway equipment immediately available for any procedure involving sedation
Perform a thorough pre-sedation assessment including airway evaluation and review of fasting status
Do not hesitate to use supplemental oxygen and a capnograph if available
Titrate medications to effect, not just to a dose
Never leave a sedated child unattended.
Common Mistakes:
Inadequate fasting leading to aspiration
Failure to perform a thorough airway assessment
Using adult-sized equipment on pediatric patients
Over-sedation leading to respiratory depression or apnea
Inadequate monitoring of vital signs
Not having resuscitation equipment readily accessible.