MIDAZOLAM FOR CONSCIOUS SEDATION DURING PEDIATRIC ONCOLOGY PROCEDURES - SAFETY AND RECOVERY PARAMETERS

Multiple bone marrow aspirations or biopsies and lumbar punctures are a necessary part of the diagnosis and treatment of many pediatric cancer patients. Pharmacologic sedation may decrease the distress associated with these procedures. Midazolam (MDZ, Versed) is a water-soluble, rapid-onset, short-duration benzodiazepine that has not been studied widely in children. We prospectively evaluated safety and recovery parameters for intravenous MDZ used for conscious sedation by oncologists (without an anesthesiologist in attendance) for 70 procedures (bone marrow aspirations, lumbar punctures, or bone marrow aspirations plus lumbar punctures) in 24 ambulatory pediatric cancer patients, aged 1.5 to 15.5 years. MDZ was used alone or in combination with morphine or fentanyl. Respiratory rate, oxygen saturation, blood pressure, and heart rate were monitored. Sedation, anxiolysis, and recovery were assessed with a behavior score and a modified recovery room discharge score. Restraint was not required in 45% of the procedures. In no case was a respiratory rate < 12 observed. In nine procedures (13%), an oxygen saturation less-than-or-equal-to 90 occurred, all within 10 minutes after the last dose of MDZ. Ten procedures (14%) required verbal stimulation to take deeper breaths. Two patients did not respond immediately to verbal stimulation and received face-mask oxygen. Hypoxemia was not correlated with opioid use. Hypoxemia appears to be related to total MDZ dose and may occur with normal respiratory rates; all cases resolved with verbal stimulation or face-mask oxygen without specific airway maneuvers or assisted ventilation. Heart rate and blood pressure remained stable in all 70 procedures. In all 70 procedures a satisfactory discharge score was achieved by 60 minutes after the last dose of MDZ. Full or partial amnesia was reported in 90% of the procedures. No long-term adverse effects were reported on follow-up. Midazolam appeared to offer effective sedation and amnesia in children undergoing bone marrow aspirations or lumbar punctures. Safe administration requires constant observation, use of pulse oximetry, and availability of supplemental oxygen and resuscitation equipment because significant hypoxemia can occur in patients breathing room air. A recovery period of 60 minutes appeared to be adequate.