Pediatrics Volume 120, Number 6, 2007
Objective:
To determine the safety profile of propofol (a sedative-hypnotic agent) as a deep-sedation agent in a primarily outpatient program consisting of pediatric critical care physicians and specifically trained nurses with oversight provided by anesthesiology. Propofol's phamacologic properties as a deep-sedation agent iclude rapid onset, predictable level of sedation, and rapid recovery with minimal adverse effects. One hypothesis was investigated in this study: adverse events and/or airway interventions are more likely to occur in children with an abnormal airway score.
Methods:
All patients who received deep sedation during a 36-month period at two Children's Hospitals were included in this prospective study. Children were only excluded if no attempt at sedation was made because of acute illness or a condition that required the specialized skills of an anesthesiologist. All sedation venues were equipped with cardiorespiratory monitoring, pulse oximetry, oxygen, suctioning, a pediatric cardiopulmonary resuscitation cart and "Dr. Blue" activation switch (cardiopulmonary arrest signal). End-tidal CO2 used for pts undergoing MRI and as needed when risk factors are present.
Sedation Process:
A presedation assessment is administered and confirmed by the sedation nurse and intensivist. All pts receive supplemental oxygen and are monitored . Sedation level is monitored according to a std score and recorded every 3 minutes . The score is based on a previously devised 5-point sedation scale (1) agitated (2) alert (3) calm (4) drowsy (5) asleep, nonrousable and does not respond to minor stimulation. Intermittent bolus doses of propofol are used for short procedures, whereas an initial bolus, followed by continuous infusions used for longer procedures. Propofol dosing was rarely less than 2mg/kg. Continuous infusion in most cases is initiated at 150 micrograms/kg /min and titrated to effect. Supplemental boluses of 1-2 mg/kg are commonly used to maintain the patient's lack of movement through the procedure.
Airway Score:
Airway class I patients do not have historical features that seem to place them at increased risk for airway compromise during sedation. Class 2 patients exhibit any of the following: current stridor, snoring, obstructive sleep apnea, morbid obesity, craniofacial malformation, symptomatic asthma or heart disease, Gastroesophageal reflux disease, swallowing dysfuncion, or previous airway problems with sedation or anesthesia. All airway class 2 or ASA 3 patients were reviewed by the critical care physician for possible referral to anesthesiology for sedation care.
Results:
The following adverse reactions were identified, and statistical analysis of the data were performed:
- mild oxygen desaturation (85-90%)--1.73%
- serious oxygen desaturation (<85%)--2.9%
- laryngospasm --0.27%
- regurgitation without aspiration--0.05%
- regurgitation with aspiration --0.01%
- bronchospasm --0.15%
- hypotension --31.4%
- cases requiring oral airway --0.96%
- nasal trumpet --1.57%
- rescue breaths for >1 min. --0.37%
- intubation --0.03%
- sedation-induced ward or PICU admission --0.04%
- cardiac arrest medications --0%
- aborted sedation or procedure --0%
Conclusions:
Hypotension was commonplace but not problematic. It carries the potential as an additive hazard for the rare child who experiences a major complication such as anaphylaxis or severe bronchospasm. Respiratory events were common, particularly desaturation, but more study is required to determine the actual incidence of alveolar hypoventilation masked by supplemental oxygen therapy in the setting of a sedatio program. The airway score derived from a formatted questionaire seems to be predictive of respiratory events and interventions but requires more refinement to be of greater value. Actively seeking potential airway complications before they occur is a powerful educational concept that may benefit practitioners
