Efficacy and safety of atropine-midazolam-ketamine in pediatric oncology patients

This study assessed the efficacy and safety of atropine-midazolamketamine as a sedative or analgesic regimen in pediatric oncology patients undergoing painful procedures. Of 136 consecutive pediatric patients undergoing painful procedures from June 1, 1997 to June 30, 1998, 69 patients (39 males and 30 females; mean age, 7.3 +/- 4.4 years) underwent 255 procedures using intravenous atropine 0.01 mg/kg plus midazolam 0.05 mg/kg plus ketamine up to 2.0 mg/ kg. Sedation monitoring forms for these 69 patients were examined retrospectively. Vital signs, pulse oximetry, patient status, clinical effects, adverse events, and patient or parent comments were recorded at 5-minute intervals from initiation of sedation until the child was awake. Clinical efficacy was defined as procedure completion with minimal patient distress; a clinically significant adverse event was defined as baseline deviation requiring acute medical intervention to prevent or ameliorate clinical deterioration. Transient clinical effects were defined as self-limited deviations in respiratory rate, heart rate, or blood pressure,15% of age-specific norms. Most of the participants were white males with leukemia or lymphoma who were undergoing lumbar punctures. Twenty-three procedures (9.0%) required additional administration of midazolam or ketamine for pain control or sedation. The 3 most frequent transient effects were hypertension in 71 procedures (27.8%), hypotension in 53 procedures (20.8%), and tachycardia in 49 procedures (19.2%). Twenty-five procedures (9.8%) had associated complications. Ten procedures (3.9%) had ketamine-associated emergent reactions, ranging from laughing and verbosity to screaming and crying. Nine procedures (3.5%) were associated with nausea, vomiting, or dry heaving, and 2 (0.8%) were associated with shaking chills after procedure completion. The clinically significant adverse event rate was 1.6% (n = 4, all during lumbar punctures). In 1 case, the procedure was terminated prematurely because of laryngospasm; in 3 cases oxygen supplementation was required because of hypoxemia. Clinically significant adverse events were associated with younger patients and increased ketamine doses. None of the adverse events had long-term sequelae, Results of the present study suggest that the atropine-midazolam-ketamine regimen is efficacious and demonstrates an acceptable safety profile in the majority of pediatric oncology patients undergoing properly supervised sedation.